=On water, vessels are propelled by:=
=a. Sails.=
=b. Steamships,= by screw, paddle-wheel, stern wheel, water jet, and
steam jet.
=c. Wave engine.=
=d. Barges and rafts= usually employ tidal motion only.
=e. Rowing boats,= &c., hand power paddle and screw boats, horse
towage.
=In air, balloons are propelled by:=
=a. Wind,= acting on the inflated balloon, or on an umbrella-shaped or
other sail; also on the under side of inclined planes of large area.
=b. Balloons= of elongated form have been propelled by an engine
placed in the car, driving either a large screw propeller or wings.
c. Various attempts have been made to work flying machines (generally
having some form of wings) by the power of a man’s hands and feet,
with very little success.
Section 60.--MOTIVE POWER.
It is assumed that all physical energy is derived more or less directly
from the sun, whose rays combine: 1, heat; 2, light; 3, actinic or
chemical power.
=Heat= may be obtained:
a. By direct use of the sun’s rays.
b. From any combustible material.
c. From chemical reaction.
=Light= does not separately develop power.
=Chemical reactions= are employed to develop heat, combustion,
contraction, or expansion, as means of developing power.
From the foregoing elementary physical sources the following are the
practical sources of our power for mechanical purposes.
Electrical power.
Magnetic power.
Tidal motion.
Falling water.
Descending weights.
Wave motion.
Wind.
Expansion of air or other gases.
Steam.
Explosives.
Fuels, hydrocarbons, &c.
These are employed in producing power by the following apparatus or
motors:--
=Electric motors= driven from a dynamo, battery, or accumulator.
=Magnetic power= cannot be employed continuously as a motor, as it
gives out only as much as it receives.
=Tidal motion= can be utilised to drive any kind of wheel, see Water
Wheels, Section 90. It can also be stored in a reservoir, driving a
water engine as it flows in and out on the flood and ebb; or a
floating vessel may, by its rise and fall, communicate motion to
machines.
=Falling water;= for machines employed to utilise, see Water Wheels,
Section 90; Turbines, Water-pressure Engines, &c., Section 93.
=Descending weights= must first of course be raised, absorbing as much
power in raising as they give out in falling, neglecting friction.
Clockwork; water; or compression of a spring (see Section 80);
multiplying pulleys (see Section 42), are the apparatus employed to
utilise this form of energy.
=Wave motion= is too uncertain and erratic to be a practicable source
of power. Rocking air-compressing chambers, rocking pumps, &c., have
obtained some small measure of success.
=Wind,= windmills. See Section 95.
=Expansion of air and gases.= Ascending currents of hot air from a
fire are used to drive a light screw motor, fan, &c. Hot-air engines,
see Ryder’s patent and numerous others, which depend upon alternate
expansion and contraction of air by heating and cooling. Air
compressed in an accumulator or reservoir is employed to give motion
to multiplying pulleys or an air engine.
=Expansion of liquids,= other than water (by heat), into the gaseous
form. Engines in which the fuel is burnt under pressure and the total
products of combustion employed (with or without steam) to drive a
motor.
=Steam= is in reality one of the last-mentioned sources of power; it
is employed by direct pressure on a piston or ram (see Section 32); or
to produce direct rotary motion (see Section 75); also in the jet
pump, No. 801; or injector (see Section 45); or by direct pressure on
a body of water contained in a closed vessel, as in the pulsometer,
steam accumulator, &c.
=Explosives= are substances which, by application of flame, heat,
percussion, &c., suddenly assume the gaseous form, thus increasing
their bulk many hundred times, usually in a small fraction of a second
of time. A second class comprise explosive mixtures of gases, such as
hydrogen, and oxygen, carburetted hydrogen, and air. Some attempts
have been made to employ explosive substances to drive engines in
various ways, but with no permanent success. The second class of
explosive mixtures of gases are largely employed in the gas engine,
petroleum engine, and their varieties.
=Fuels, hydrocarbons,= &c., are employed to evaporate water into
steam; to expand air or other gases, or convert liquids into gases;
and also by vaporisation to supply gas for use in some forms of gas
engine.
Section 61.--PUMPING ENGINES, TYPES OF.
VERTICAL ENGINES.
=1114. Vertical direct-acting,= with either ram pump, ram and piston
pump, or piston only. See Section 56.
=1115. Slot and crank motion,= a variety of the last named. Of course
any other kind of crank driving can be employed. See Section 10.
The frame standards are frequently used as air vessels or valve
chests.
=1116. Direct-acting ram pump,= with fly-wheel worked off crosshead pin.
=1117. Direct-acting,= with yoke crosshead; much used in the northern
counties. The standards form air vessels and valve boxes, and they are
made both of the piston and ram types.
=1118. Three-cylinder,= with yoke crosshead. Either the centre cylinder
or the two side ones can be used as the steam motor cylinders, or the
pumps.
HORIZONTAL ENGINES.
=1119. The ordinary direct-acting engine,= with either steam-moved or
tappet valves, see Tangye’s “Special,” the “Coalbrookdale,” and others,
in which the slide valve is operated by pistons controlled by auxiliary
tappet valves on the same principle as No. 1506.
=1120. Direct-acting,= with crosshead and guide bars between the
cylinders.
=1121. Two modifications of No. 1120.=
=1123. Direct-acting,= with rocking lever valve motion; see the
“Worthington” and other “Duplex” pumps, in which two engines are
combined so that one works the valve of the other.
=1122, 1124, & 1125. Other forms of direct-acting engines.=
=1126. Horizontal compound direct-acting.= The high-pressure cylinder,
low-pressure ditto, and receiver are side by side, and the air pump and
main pump in line with the steam cylinders.
[Illustration: 1112.-1126.]
=1127. Horizontal pumping engine,= with yoked crossheads and crank in
centre.
=1128 & 1129. Horizontal compound lever engines.=
=1130. Davey’s patent vertical compound beam mining pump.=
The Cornish beam pumping engine is too well known to need
illustration.
In mining pumps the pump rod has occasionally been made of iron pipe
and employed as the rising main.
=1131. Geared pumping engine,= with steam cylinder and pump side by
side; the speed of the steam piston is reduced on the pump by spur
gearing.
Section 62.--PAWL AND RATCHET MOTIONS.
INTERMITTENT MOTION.
=1132. The common ratchet-wheel and pawl,= or detent.
=1133. Ditto,= with compound pawls to check angular motion less than the
pitch of the teeth.
=1134. Locking pawl.=
=1135. Strut-action pawl.=
=1136. Indiarubber ball pawl;= sometimes a solid roller is substituted
for the indiarubber ball.
=1137. Reverse ratchets,= for continuous feed from an oscillating arm.
=1138. Ball and socket ratchet,= will work at an angle.
=1139. Pawl,= used with ordinary spur teeth, and sometimes made
reversible (see dotted lines), to drive the opposite way.
=1140. Ratchet bosses.=
=1141. Silent pawl;= the pawl is lifted out of gear while reversing by
the motion of the toggle joint and lever.
=1142. Crown ratchet and pawl.=
=1143. Application of No. 1136= as a silent feed motion.
=1144. Click and detent continuous feed motion.=
=1145. Hare’s foot ratchet motion= with detent.
=1146. Silent feed.= The jaw grips the rim of wheel when moving in one
direction and runs loose the other way.
=1147. Reciprocating= into intermittent rotary motion.
[Illustration: 1127.-1147.]
=1148. Reciprocating circular motion= into intermittent circular ditto,
Kaiser’s patent.
=1149. Continuous circular motion= into intermittent ditto, Kaiser’s
patent. The wheel ~A~ is locked by the ring ~C~ while the finger ~B~ is
out of gear, the ring then passing between the teeth of ~A~.
=1150. Cam-ring intermittent feed motion.=
=1151. Modification of the last named;= in both the wheel is locked
during the dead movement of the cam by the flange passing between the
teeth.
=1152. Slot wheel and pin gear.=
=1153. Segment-wheel intermittent feed motion;= locked during the dead
movement of driving wheel.
=1154. The pawl is lifted out of gear= at each revolution of the pin
wheel ~A~ and the ratchet moved one or more teeth.
=1155. Double pawls and links= for continuous feed motion.
=1156. The cam= ~A~ is eccentric to the wheel ~B~, and slips out of gear
at any required point while the driving wheel makes a partial
revolution.
=1157. Spring-pawl feed motion;= the large wheel with pawl attached
drives the ratchet wheel.
=1158. Rocking lever and double pawls= for raising a rack.
=1159. Internal pawls,= dropping into gear by gravitation.
=1160. The pawl is lifted out of gear= by the act of putting the handle
on the square end of shaft, the handle having a boss shaped so as to
lift the pawl.
=1161. Star wheel and fixed pawl= for conveying intermittent motion to
screw on revolving disc; used for boring-bars, slide rests, &c.
=1162. Pendulum and ratchet escapement.=
=1163. Cylinder escapement.=
=1164. Pendulum and double ratchet wheel escapement.=
=1165. Enlarged plan of cylinder escapement.=
=1166. Lever escapement.=
=1167. Double pawl and pin wheel escapement.=
=1168. Three-leg pendulum escapement.=
=1169. Self-sustaining ratchet motion.= Pulling the cord ~A~ throws the
pawl out of gear by the straightening of the cord forcing back the bent
pawl lever.
=1170. Verge escapement.=
=1171. Intermittent circular motion= by revolving pawl and detent.
[Illustration: 1148.-1171.]
=1172. Spanner ratchet;= a simple spanner having a pin near one end of
one of the jaws which slips into the teeth of the ratchet wheel.
=1173. ~V~ pawl;= operates by wedging itself between the ~V~ flanges.
=1174. Gravity pawls and ratchet wheel.=
=1175. Ratchet wheel,= used to govern the striking gear of a clock.
=1176. The pawl is hinged to the jointed end of the lever,= and is
pulled out of gear by the return movement of the rod--silent feed.
=1177. Pawl and rack.=
=1178. Roller and inclined segmental recess= for silent feed motion.
=1179. Gripping pawls and ring= for silent feed motion.
Snail ratchet, No. 725.
Section 63.--PRESSING.
The ordinary Screw press and Hydraulic press are well-known machines.
=1180. Rack and screw press.=
=1181. Power press or stamp,= with double crank movement worked from
below.
=1182. Dick’s anti-friction press,= with rolling contacts throughout.
=1183. Hydraulic press,= with dies for lead pipe making; a similar press
is used for making earthenware drain and flue pipes, the material being
forced out of an annular orifice.
=1184. Wedge press.=
=1185. Ster-hydraulic press;= a strand or rope is wound upon a barrel
inside the cylinder, thus displacing the water and raising the ram.
=1186. Screw fly press.=
=1187. Combined screw and hydraulic press.= The screw is worked down by
hand until the pressure becomes too great for hand power, when the
pressing is finished by the hydraulic ram.
=1188. Revolving dies.=
=1189. The “Boomer” double-screw toggle press,= with increasing pressure
as the press follower descends.
=1190. Revolving toggle press,= with similar capabilities but more
restricted movement.
=1191. Sector and link press= for increasing pressure.
[Illustration: 1172.-1191.]
=1192. Press dies,= with sliding plate for discharging.
=1193. Screw and toggle press;= a modification of No. 1189.
=1194. Double ram hydraulic press= for two pressures; the small ram is
employed to give the first pressure, the large ram then finishes the
pressing.
See also Section 13.
Section 64.--POWER AND SPEED, CONTRIVANCES TO VARY.
(See Mechanical Powers, Section 53.)
Section 65.--QUICK RETURN MOTIONS.
Employed for machines having a slow movement one way, and a quicker
return movement.
=1195. Slot lever and crank motion;= gives a varying speed, quickest
when the crank pin is at the bottom centre, and slowest when at the top,
with a slight pause at each end of stroke.
=1196. Whitworth’s motion.= The pin ~A~ in the wheel ~B~ travels
eccentrically in the crank disc, which is eccentric to the fixed boss on
which the driving wheel ~B~ runs, so that the radius of the driving
motion of the pin varies as it revolves and it travels up and down the
slot in the disc.
=1197. By two belts,= one open and one crossed, and driving drums of
different diameters.
=1198. By two belts,= one open and one crossed, but driven by the same
drum. The middle pulley is loose, the left hand pulley is fast to the
spur wheel, and the right hand pulley to the spur pinion.
Segment gear, gearing alternately with the internal ring and the
central pinion. See No. 724.
See Section 74.
Section 66.--ROPE GEARING.
=1199. ~V~-grooved pulley rim= for round rope.
=1200. Multiple pulley rim,= used for rope driving in mills, &c.
=1201. Single ~V~-grooved pulley= for hand ropes.
=1202. Pulley for wire rope= transmission, with wood bedding in the
groove.
=1203, 1204, & 1205. Clip pulleys,= which grip the rope by its own
tension.
=Ordinary round grooved pulley.= See Section 71, No. 1241.
=Rope grip pulley,= with snugs to wedge the rope and prevent slipping.
See Section 71, No. 1242.
=Pit head sheave.= Used for quick running wire ropes. The boss is
usually split to allow of expansion in cooling, and the arms are of
wrought iron. See Section 71, No. 1243.
=1206. Rope driving.=
=1207. Rope driving,= with tightening pulley and weight.
=1208. Rope grip pulleys,= for driving a vertical rope, the large pulley
has a ~V~ groove into which the rope is pressed by the small pulley.
=1209. Jigger hoisting rope gear,= used for whip cranes, &c., instead of
spur gearing.
=Wire rope transmission.= Endless wire ropes of small diameter are
used running over large pulleys and driven at a high speed (usually
3000 to 4000 feet per minute). This kind of power may be carried
considerable distances and over uneven ground, but it is not desirable
to have horizontal angles in the direction of the rope.
Section 67.--RESERVOIRS OF POWER. ACCUMULATORS.
=a. The fly-wheel= or its equivalent.
=b. Springs.= See Section 80.
=c. Weights.=
=d. Air or gas compressed into a reservoir;= air vessel, bellows. See
Section 7.
=e. Water raised into an elevated reservoir= or tank, or pumped into a
loaded accumulator. Variable Pressure Accumulator, No. 1586.
=f. Electricity stored in accumulators.=
=g. Explosives.=
=h. Pendulum.= Sometimes used to accumulate power to be given out
suddenly, as in punching.
Section 68.--RECIPROCATING AND CIRCULAR MOTION, CONVERTING ONE INTO THE
OTHER.
(See Circular and Reciprocating Motion, Section 21).
(See Pawl and Ratchet Motions, Section 62).
Section 69.--RAISING AND LOWERING.
(1.) BY HAND POWER.
=a. The ordinary winch and crank handle.=
=b. Winch,= worked by an endless hand rope and wheel, similar to Nos.
1210, 1220.
=1210. Hand rope and barrel hoist.= In this machine gearing may be
interposed between the hand rope wheel and rope drum to increase the
power and reduce speed.
=c. Differential blocks= of various patterns (see Weston’s, Pickering’s,
Moore’s, &c.). See Section 31.
=d. By screw gear,= as in the ordinary screw jack. Sec. 78.
=e. Rack and pinion gear.= See No. 754.
=f. Worm and wheel gear.= See Section 84.
Note as to brake wheels: these should always be upon the _load_ shaft
so that the braking is not transmitted to the load through toothed
gearing. Worm gear usually will not sustain a load without a brake
wheel, unless there is an excess of friction which should not exist.
=g. Friction gear.= See Section 38.
(2.) BY POWER.
This may be applied to any of the above as follows:--
=a or b.= To the ordinary winch by either gearing (see Section 84),
belts (see Section 3), or friction gear (see Section 38).
=b. By gripping= the endless rope between grip wheels (see 1208) the
small wheel can be thrown into gear to grip the rope by a lever, cam or
screw.
=c. Differential gear= may be driven from a shaft by belts or gearing.
See Sections 84 and 3.
=d. Screw gear.= Ditto.
=e. Rack gear.= Ditto.
=f. Worm and wheel gear.= Ditto.
=g. Friction gear= is usually driven as No. 1211.
=1211. Where the barrel shaft has a slight horizontal movement,= so
that, by the lever, it can be forced into gear with the friction pinion
to raise the load, or into the brake block to sustain the load or lower
it.
Grooved friction ~V~ gearing is also sometimes used. See No. 667.
[Illustration: 1192.-1211.]
(3.) HYDRAULIC GEAR. See Section 42.
=The direct-acting plan= is simply a ram and cylinder, as in the
hydraulic press, the ram being as long as the height of travel of the
cage. For multiplying cylinder hydraulic gear, see Section 42.
=Balancing the dead load of cage, &c.= This is usually done by weights
attached to the end of ropes running over overhead pulleys and
fastened to the cage, as in No. 370, or by an auxiliary cylinder and
ram of short stroke loaded to the required weight, and communicating
with the lift cylinder by a pipe. See Section 20.
(4.) FOR LOWERING WEIGHTS ONLY.
=a. An hydraulic cylinder and piston= may be used, to which the cage is
directly attached either above or below, the cage or platform being
overbalanced by a counterbalance weight and rope (running over a pulley
as No. 370), which is sufficient to raise it empty. The speed is
controlled by a pass valve which allows the water to pass from one side
of the piston to the other. See Section 5.
=b. An ordinary ~V~ wheel and brake wheel= may be used, the cage being
overbalanced as last described; the motion is controlled solely by the
brake. Or, an hydraulic brake cylinder may be used in connection with a
rope or chain attached to the cage. See note to Section 5.
Other hoisting devices are:
=Direct-acting steam or air cylinders,= the piston rods being coupled
direct to the cage.
=Air vessels,= on the principle of the gasometer, but of a height
equal to the travel, and diameter proportional to the pressure of air
employed.
=1212. Internal screw elevator.= The vertical shaft has a feather
groove, and carries a double crosshead with a wheel at each end, which
run on the spiral guides and raise the cage.
=1213. Screw elevator,= for ice, &c. Vertical creeper.
=1214. Travelling hoist,= with in and out motion and rope.
=1215. Steam digger and hoist.=
=1216. Hauling capstan.= The rope, which is payed on and off the barrel,
“fleets” itself as it travels along the barrel owing to its conical
shaped flanges.
=1217. Richmond’s patent differential telescopic hydraulic lift.= The
water under each piston is forced into the next cylinder above, so that
the rams all travel upwards at proportional speeds, so as to reach the
top of their stroke at the same time.
=1218. Self-sustaining gear.= The revolution of the pinion tends to lift
the barrel and its brake wheel out of the brake; lowering is performed
by relieving the brake wheel by a lever which raises it from the brake.
Cherry’s patent.
=1219. Belt hoist.= Worked by a loose vertical belt, which is tightened
by the lever and pulley when required to hoist, and in lowering a load
the belt friction acts as a brake.
=1220. Travelling hand hoist,= with endless rope.
=1221. Travelling cathead hoist.= The cathead can be run back with its
load; the winch is sometimes fixed to the travelling beam and moves in
and out with it.
=1222. Winding engine,= usual type for direct acting.
=1223. Geared winding engine.=
=1224. Steam winch, horizontal arrangement.=
=1225. Steam winch, diagonal arrangement.=
=1226. Steam winch, horizontal worm-gear plan.=
[Illustration: 1212.-1226.]
=1227. Continuous lift,= for parcels, &c. Has a number of small cages,
boxes, or platforms suspended from horizontal pivots in two endless
chains; the cages are guided so as always to hang vertical.
=1228. Continuous lift,= for passengers. Sometimes the cages are
suspended from two endless chains at their tops, as last described; or
sometimes from two endless chains, but with attachments to the cages at
corners diagonally opposite each other; and sometimes from a single
endless chain at the back, provided with guides, &c.
=1229. Continuous barrel hoist.=
See also Cranes, Section 18.
Section 70.--RELIEVING PRESSURE ON BEARINGS. ANTI-FRICTION BEARINGS.
=1230. The pivots of two rollers or shafts= bear against the inside of a
stiff ring producing rolling contact, but the rollers or shafts must run
in the same direction. Used for roller mills, &c.
=1231. The same device, but for three rollers= or shafts.
=1232. The shaft is guided vertically= and its weight is borne by a
large roller with small pivots.
=1233. The shaft runs in the ~V~ between two rollers= as last described.
=1234. Roller or ball bearing.= The friction is least when the rollers
have end pivots to run in loose rings so that the rollers are kept apart
and do not rub each other in revolving.
=1235. Hydraulic bearing,= the shaft being sustained by water (or
preferably oil) pressure.
=1236. Vertical shaft,= with cone rollers.
=1237. Vertical shaft,= with ball bearing.
=1238. Vertical shaft,= flanged and coned for cone rollers.
=1239. Ordinary swivelling castor.=
=1240. Ball castor.=
Section 71.--ROPE, BELT, AND CHAIN PULLEYS.
(See also Section 66.)
=1241. Pulley for round rope= without any grip.
=1242. Round grooved pulley= for round rope with gripping snugs.
=1243. ~V~ pulley for round rope;= pithead pulley.
=Pulley for wire rope transmission,= high speed with wood bedding. See
Section 66, No. 1202.
=Multiple rope gripping pulley= for rope driving. See Section 66, No.
1200.
=1244. Belt pulley,= flat fare.
=1245. Belt pulley,= crown face. The rounding tends to keep the belt
from running off.
=1246. Flanged belt pulley.=
=1247. Speed cone for belt.=
=1248. Round grooved chain pulley.=
[Illustration: 1227.-1248.]
=1249. Double grooved chain pulley;= prevents the chain twisting.
=1250. Pitched chain snug pulley or sprocket pulley.= The pitch of snugs
should be slightly longer than the chain, to allow for wear and
stretching of the chain.
=1251. Chain sprocket wheel,= for long link chain at slow speeds.
=1252. Sprocket wheel,= for long flat link pitched chains.
=1253 & 1254. Sections of rim= showing single and double links.
=1255. Sprocket wheel,= for Ewart’s patent pitched chains. See Chains
&c., Section 11.
Section 72.--RIDDLING AND SCREENING.
=1256. Square mesh wire gauze.=
=1257. Perforated plate.=
=1258. Parallel bars or wires.=
=1259. Hexagon or triangular mesh wire work.=
=1260. Slit and square hole perforations,= used for seeds, &c.
A form of variable mesh is manufactured by parallel series of diagonal
bars jointed by pins to sliding cross-bars, so that the angle of the
mesh bars can be altered and thus the spaces reduced or enlarged, on
the same principle as No. 617.
=1261. Sloping screen.=
=1262. Cylindrical or slope reel screen.=
=1263. Cylindrical graduated screen or sizer.=
=1264. Rotary screen,= with rolling bevil gear motion. See No. 711.
=1265. Rotary horizontal screen.=
=1266. Shaking or jigging screen.= Sometimes supplied with a blast or
aspirator to carry off the lighter particles.
=1267. Eccentric or angular barrel screen or mixer.=
=1268. Air blast sizing or graduating apparatus.=
=1269. Edison’s magnetic sizing apparatus= for iron or steel particles.
[Illustration: 1249.-1269.]
=1270. Graduating or sizing screens,= either fixed as shown or kept in
motion like No. 1266.
See also Concentrating and Separating, Section 26.
Section 73.--RAIL AND TRAM ROADS.
=1271. Square bar rails.=
=1272. ~L~-iron tram road;= often made of cast-iron with the joints
dove-tailed together.
=1273. ~T~-iron tram road.=
=1274. Tram road,= with flanged plates for ordinary vehicles.
=1275. Tram road,= with one channel plate and one flat plate.
=1276. Bridge rail.=
=1277. Bulb-head flanged rail.=
=1278. Double headed rail.=
=1279. “Barlow” rail.=
=1280. Bulb rail.=
=1281. Flush grooved tramway rail.= See Nos. 1839-1841.
=1282. Rolled joist rail.=
=1283. Bulb-iron rail.=
=1284. Edge’s patent perforated rail and toothed wheel.=
Many forms of combined chair and sleeper are manufactured in wrought
iron and steel.
=1285. Left-hand switch.=
=1286. Shunting carriage,= for transverse shunting; carries a short
section of the main road and runs across it on independent rails laid on
a lower level; often used instead of a turntable for shunting.
=1287. Tramway switch.=
[Illustration: 1270.-1287.]
=1288. Right and left-hand switch and crossing,= showing arrangement of
guard-rails.
=1289. Flat bar= on edge rail.
See Section 99 for other sections of rails.
Section 74.--REVERSING GEAR.
For Reversing Gear of Steam Engines, see Section 79.
=1290. Reversible driving motion= by open and crossed belts, with two
loose and one fast pulleys.
=1291. Reversible driving motion= by single belt, two fast pulleys and
one loose ditto and bevil gear, one bevil pinion having a sleeve to
which its fast pulley is keyed, the other bevil pinion being keyed to
the shaft.
=1292. Reversible driving motion= by single belt, with quick and slow
motions; a modification of the last.
=1293. By double clutch and bevil gear.=
=1294. Reversing friction cones or bevils.=
=1295. Three-wheel gear.= The driving wheel ~A~ can be put into gear
either with the driven wheel ~C~ or idle wheel ~B~.
=1296. Double clutch and spur gear= reversing motion, with idle wheel.
=1297. Reversing pinions,= as used on the ordinary screw-cutting lathe.
There are many varieties of this gear in use.
=1298. Application of single belt gear to= No. 1296.
=1299. Self-reversing gear,= with one belt, two fast and one loose
pulleys. The large spur wheel is driven from the bevil gear, and carries
the weighted lever past the vertical position by a stop on the
face-plate or disc, when it falls over and reverses the belt fork. See
No. 1026.
[Illustration: 1288.-1299.]
=1300. Self-reversing gear,= as applied to planing machines. The stops
can be set at any required distance apart, to alter the length of travel
of the machine bed. This plan requires a heavy table to carry the belt
across the loose pulley to the other fast pulley.
=1301. Reversible belt-shifting hand gear.=
=1302. Right and left hand screw reversing traverse motion.= Each lever
has a half nut, which can be put in gear with the screw to drive either
way. See also No. 163.
=1303. Best form of fast and loose pulleys= for open and crossed belt
reversing gear, as used in No. 1290; the fast pulley is rather larger in
diameter than the two loose ones.
=1304. Single-belt reversing pulleys,= the reverse motion on the shaft
being obtained by intercepting an idle wheel ~A~ between the
epicycloidal wheel ~B~ and the shaft pinion ~C~, the middle pulley being
the loose one; the idle wheel is carried by a fixed bracket and pin.
NOTE.--Reversible motion can be obtained direct from any steam engine
fitted with reversing motion. See Valve Motions, No. 1436, &c.
Segment Reversing Gear, No. 724.
Section 75.--ROTARY ENGINES, PUMPS, &c.
Nearly all rotary engines can be used either as motors, pumps, blowers,
or meters, and most of the following typical devices have been applied
to all four purposes. Most of them are reversible by simply reversing
the direction of the motor fluid.
=1305. Disston’s;= used as a pressure blower.
=1306. Root’s, blower and pump.=
=1307. Root’s.=
=1308. Mackenzie’s;= may have one, two, or three vanes.
=1309. Gould’s.=
=1310. Bagley and Sewall’s.=
=1311. Greindl’s rotary pump.=
=1312, 1313, 1314, & 1315. Varieties of intergeared piston rotary
engines.=
[Illustration: 1300.-1314.]
=1316. The small crescent-shaped piston= revolves three times to one
revolution of the three-armed piston.
=1317. The hinged shutter= is thrown out of the way each time the
revolving arm passes it.
=1318. Sliding shutter= and cam piston device.
=1319 & 1320. Varieties of the “Root” engine.=
=1321. The hinged vanes= are closed upon the revolving piston as they
pass the flat side of the casing.
=1322. Has an eccentric piston and two hinged vanes.=
=1323. Eccentric piston and sliding diaphragm.=
=1324. Klein’s motion.= The eccentric ring revolves in contact with the
inner and outer casings, but is prevented from revolving on its axis by
the fixed shutter and slot.
=1325. Baker’s pressure blower.=
=1326. A modification of No. 1323.=
=1327. The eccentric ring= revolves on its centre, allowing the vanes to
alternately project into the steam space as the wheel revolves.
=1328. Ivory’s.= An eccentric cam and two sliding shutters, with a
central steam inlet.
=1329. Mellor’s= has a rocking vane oscillated by an eccentric piston
carried round by a crank.
=1330. Eccentric piston and two sliding vanes= or steam stops.
=1331. Differential rotary engine,= with elliptical gear (see Section
34), or Stewart’s differential gear (No. 554) may be employed.
=The “Tower” spherical engine= is a well-known form of rotary engine.
See _Engineer_, August 10th, 1883.
=1332. An eccentric four-armed piston,= with four rolling stoppers or
packings.
=1333. Mellor’s patent pump= has a rocking vane or partition, with
packing device which accommodates itself to the revolving oval piston.
[Illustration: 1315.-1333.]
=1334. Bisschop’s disc engine,= with three or four cylinders, single
acting, whose rams press alternately on the edge of the disc.
=1335. Another form of disc engine,= in which partitions (rising and
falling vertically) form the steam stops.
=1336. A modification of 1316.=
=1337. Rotary or centrifugal pump= or fan, numerous varieties of which
are in use. Many of the later forms, as Blackman’s and others, have the
vanes fixed diagonally so as to propel the air at right angles to the
plane of motion.
Section 76.--SHAFTING.
Employed to convey motion from a motor to various forms of driven
machinery by gearing of various kinds. See Sections 3, 11, 38, 40, and
84.
Materials employed are:--Round, square, or polygonal wrought iron or
steel bars, cast iron, wood, iron or steel tubes, planished round iron
and steel bars, &c.
=Stow’s flexible shafting.= See No. 442.
=1338. Longitudinal section of a cast-iron shaft.= These are sometimes
made of a ~X~ section.
=1339. Wooden shaft= with end ferrules and iron end centres.
=1340, 1341, & 1342. End view and sections of ditto,= solid hexagonal
and hollow circular.
=1343, 1344, & 1345. Arrangements of line shafting= in a machine-shop or
factory, with or without overhead travelling crane.
=1346. Example of a line shaft,= showing bearings (see Section 46),
couplings (see Section 16), pulleys (see Section 3), and gearing (see
Sections 3, 84).
Shafts to be used as rollers are usually made hollow of wrought iron
or other metal tube, tin plate, zinc plate, or sheet iron riveted; or
sometimes, as No. 1342, of wood laggings fixed to solid polygonal
blocks or centres, either continuous or in short pieces fixed at
intervals.
See also next Section (77).
Section 77.--SPINDLES AND CENTRES.
=1347. Spindle= with sunk end bearings.
=1348. Spindle= with one sunk bearing and one collar.
=1349. Plain spindle= with two loose collars. Where pedestals with loose
caps are used (see Section 46) the collars may be solid with the
spindle, but with a long shaft the collars should be at one end only as
shown, to allow of expansion. A wheel frequently occupies the place of
one or both collars, and serves the same purpose.
[Illustration: 1334.-1349.]
=1350. Coned centre,= fixed.
=1351. Collar centre pin or stud bolt,= fixed.
=1352. Coned centre= for roller or similar detail, driven in place.
=1353. Parallel centre= for roller or similar detail, keyed in place.
=1354. Square centre= for crane barrel, &c. See Nos. 634 and 635.
=1355 & 1356. Lathe headstock spindles,= solid or hollow; sometimes made
with conical and sometimes with parallel necks.
=1357. Conical crane post.=
=1358. Conical cart axle.=
=1359. Universal centres,= employed to allow of a machine (or part of
ditto), such as a drill, to be adjusted at any possible angle, the
machine being fixed to one end of bar ~A~.
=1360. Railway carriage axle.= For cranked axles, see Section 10.
=1361. Square neck centre bolt.= The square neck prevents the bolt
turning and loosening the nut.
=1362. Coned and cottered crank pin= or centre, sometimes secured by a
nut, as No. 1350.
=1363. Centre pin and bracket,= adjustable to various angles.
=1364 & 1365. Two methods of securing end of rod to any solid part of
machine;= used for steam hammer heads.
=1366. Hollow post centre,= with water or steam channel to allow for
swivelling.
=1367. Group of sleeve centres,= employed to allow of several pairs of
lever or wheel motions being taken independently on a single shaft.
=1368. Ordinary centre pin,= with nut, washer, and split pin.
=1369. Ordinary centre pin,= with split pin and washer.
[Illustration: 1350.-1369.]
Section 78.--SCREW GEAR, BOLTS, &c.
=1370. Square thread screw.= Single, double, or multiple thread.
=1371. ~V~ thread screw.=
=1372. Enlarged section of ~V~ thread.=
=1373. Strongest thread= when the strain is always in one direction.
=1374. Round thread screw.=
=1375. Geared thread,= to be used with ordinary wheel teeth, the section
of thread being that of a rack of the same pitch as wheel.
=1376. Earth screw,= screw pile, screw mooring, earth borer. See No.
530.
=1377. Fixed screw,= with hand wheel to revolve the nut, the screw
having no rotation.
=1378. Conical screw;= used for chucks, &c. With two, three, or more
sliding jaws chased to fit the conical thread.
=1379 & 1380. Differential screws.= One fixed, the other revolving,
impart a motion equal to the difference of pitch of the two screws (see
Section 31). See No. 1430.
=1381. Screw,= with half nut; the bearings of the screw being fixed act
as a fulcrum for the motion of the half nut, which may be attached to
any sliding device; employed for jaw chucks.
=1382. Screw and worm gear,= used for screw jacks, &c. The worm gears
with a worm wheel having a central nut running on the main screw.
=1383. Mutilated screw and nut.= In one position the nut can slide on
the screw, and a partial turn locks it. Used for instantaneous grip
vices, &c.
=1384. Spiral worm= for three or four jaw chucks, expanding devices, &c.
See Sections 28 and 36.
=1385, 1386, & 1387. Screw driver heads= for screws.
=1388 & 1389. Hexagon and square heads= for ordinary spanners.
=1390. Form of head= requiring special spanner or pointed bar.
[Illustration: 1370.-1390.]
=1391. Cylinder head bolt,= with drilled holes and special spanner.
=1392. Cylinder head,= but with flutes instead of holes for spanner.
=1393. Cylinder head,= but with two flats cut on the head to suit an
ordinary spanner.
=1394. Socket head,= to receive a second screw.
=1395. Eye bolt.=
=1396. Thumb screw.=
=1397. Thumb or shutter screw.=
=1398. Milled head screw.=
=1399. ~T~ head screw.=
=1400. Thumb or fly nut and screw.=
=1401. Hexagon collar stud= to receive a nut or other female screwed
fixing.
=1402. Bolt head= for forked spanner, used for sunk or countersunk
heads.
=1403. Hexagon head,= with solid washer or collar.
=1404. ~T~ head bolt= for ~T~ grooves in castings.
=1405 & 1406. Countersunk heads.=
=1407. Eye bolt,= with flat sides and straight eye for a pin or bolt.
=1408. Snap head.=
=1409. Hook bolt.=
=1410 & 1411. Lewis bolts, rag bolts.=
=1412. Cottered bolt.=
=1413, 1414, & 1415. Lewis bolts and key pieces.=
[Illustration: 1391.-1415.]
=1416. Collar stud.=
=1417. Split spring head bolt.=
=1418. Hook bolt.=
=1419. Solid head and collar bolt, bed bolt.=
=1420 & 1421. Heads for bolts= to slide and turn in ~T~ grooves of
planing machines, &c.
=1422. Countersunk bed bolt.= Boiler stay.
=1423, 1424, & 1425. Methods of finishing screw heads= to prevent
catching passing articles.
=1426. Screw head,= with cross dovetails to carry a key or screwing
lever.
=1427 & 1428. Right and left-hand screw couplings= for tie rods, &c.
=1429. Ring coupling= for 2, 3, 4 or more rod ends for tie bracing.
=1430. Right and left-hand screw couplings= with halved ends to prevent
the rods turning; may be made with one fine and one coarse thread for
differential motion, or with right and left-hand threads.
=1431. Rifling,= as used in ordnance, &c., i.e. an internal multiple
screw thread of very long pitch.
=1432. Screw spanner;= the weight prevents it working loose.
=1433. Belt screw.=
=1434. Gib cotter bolts.=
See also pipe couplings, Nos. 1071, 1072, 1073, 1074, 1075, and 1062,
1068, 1070.
For spiral worms and creepers, see Section 57.
Spiral pump, No. 1022.
_Note_ that it is possible to construct a screw with an increasing or
decreasing pitch, as is done with the screw propeller. See also No.
1378.
Double screw gear, No. 727.
Snail worm gear, No. 730.
Worm and crown gear, No. 733.
Worm and spiral gear, see Section 84.
Section 79.--SLIDE AND OTHER VALVE GEAR.
It would be neither easy nor useful, besides being beyond the scope of
this work, to attempt to illustrate all the varieties of gear employed
to work the valves of steam and other motor engines. I shall therefore
only illustrate the more important types in general use, the details of
which may be varied to suit individual cases.
=1435. Is the ordinary slide valve gear= with single eccentric for
engines running always in one direction.
=1436. Ordinary link motion reversing gear= with two eccentrics; the
link, having a shifting motion, is so arranged that either eccentric can
be put into gear with the slide valve, the other eccentric running idle;
or when in the mid position, as in sketch, both eccentrics run idle and
the slide valve has no motion. By setting the link at intermediate
positions the travel of the valve can be varied, and consequently the
cut off also within certain limits.
[Illustration: 1416.-1436.]
=1437. Nicholson’s patent reversing gear,= without eccentrics. The
drawing explains itself. This gear cannot be run in the intermediate
positions, as a link motion to vary the cut off. This limits its
usefulness to simple reversing only.
=1438. Automatic governor expansion= for single eccentric engine; the
position of the connecting rod end in the swinging link is dependent on
the governor, and thus also the travel of the slide valve.
=1439. Side shaft motion= for operating Cornish, Corliss, and spindle
valves. The valves can be driven from this shaft by cams, eccentrics, or
gearing.
=1440. Gab lever= for throwing the eccentric out of gear and thus
stopping the engine.
=1441. Sector and link reversing motion= for oscillating engine;
sometimes a shifting eccentric is used instead of link motion, as No.
1443.
=1442. Reversing sector link motion= for an oscillating engine; the
valve is operated from the link, the angle of which is altered by the
hand lever, there is therefore no lead to the valve.
=1443. Shifting eccentric and balance= sometimes used for reversing
instead of double eccentrics and link; the loose eccentric is carried
round in either direction by a stop piece on the shaft, fixed so as to
give the correct lead both ways.
=1444. Murdoch’s variable expansion gear= (see _Mechanical World_,
September 29th, 1888) has one eccentric which operates a double arm
lever, the outer end of which moves a sliding fulcrum along the valve
rod lever, so that the leverage of the valve rod lever varies at
different parts of the stroke. The sliding fulcrum is attached to a
radius rod.
=1445. Proell’s automatic expansion gear.= Shown applied to special
double beat valves, but is sometimes applied to a special throttle
valve, and is then applicable to any ordinary engine. The action of the
governor alters the lap of the catches upon the ends of the valve
levers, thus varying the time that the valves are kept open; the catches
are centered on an oscillating ~T~ lever, operated from an eccentric on
the main shaft.
=1446. Marshall’s valve gear,= driven by one eccentric on crank shaft.
The sector rocking centre is moved along the curved slot to reverse the
engine, giving similar motion to the valve rod as in the case of the
ordinary link reversing gear No. 1436.
[Illustration: 1437.-1446.]
=1447. The Bremmé valve gear= with single eccentric; the valve rod is
operated by a lever and bent connecting rod from the end of the
eccentric rod; the latter is constrained to move in an arc by a
three-link attachment to a fixed bearing behind the eccentric rod and a
movable one at the right-hand end of the horizontal link. To reverse,
the arm and sector are turned to the dotted position by the worm and
hand wheel shaft.
=1448. Joy’s valve gear,= operated by a pin on the connecting rod. The
slotted ~T~ lever is connected to the hand lever for reversing, and when
reversed stands at the same angle from a vertical line but on the
opposite side. The fulcrum of the valve rod lever has a sliding motion
in the slot of the ~T~ lever.
=1449. Variable expansion gear= by hand power. There are many
applications of this type used to vary the travel of a cut-off valve.
=1450. Corliss valve gear,= operated by a single eccentric, has two
steam and two exhaust valves similar to No. 1642, worked from pins on a
rocking wrist plate. The steam valves have trips, regulated by the
governor, on a similar principle to No. 1445.
=1451. Crank shaft governor= with shifting eccentric: the centrifugal
action of the weights, acting against springs, is used to revolve the
inner eccentric so as to vary the throw of the main eccentric from which
the slide valve is driven.
=1452. Another form:= in this also the throw of the eccentric is varied
by the action of the governor ball.
=1453. Another form of automatic governor expansion trip gear= in
connection with Cornish valves; a single eccentric operates the four
valves, and the contacts of the catches and steam valve levers are
regulated by the governor, the lower or exhaust valves having a constant
motion.
[Illustration: 1447.-1453.]
=1454. Double angular slide valve= for varying the cut off by a
transverse motion given to the valve from outside, either by hand gear
or by the governor, the valve being made wider than the valve face, as
dotted lines.
=1455. H. Jack’s variable expansion gear,= with one eccentric. Patent
No. 4167/85.
=1456. Variable cut-off valve= on the back of the main slide, the rod of
which can be revolved by hand or from the governor to vary the opening
of the cut off valves.
=1457. A plan to effect the same object= but by a cylindrical cut off
valve.
=1458. English’s expansion gear.= Two eccentrics. The expansion valve
has no lap, and the gear gives a constant relative motion to both
valves.
=1459. Tappet gear,= sometimes used for water-pressure engines, &c.
Section 80.--SPRINGS.
=1460. Open spiral spring= for tension.
=1461. Close spiral spring.=
=1462. Open spiral spring= for compression.
=1463. Open spiral spring= (square thread) for compression.
=1464. Double volute chair spring.=
=1465. Spindle-shaped open or close spiral spring= for tension.
=1466. Parallel open or close spiral spring= with coned ends.
=1467 & 1468. Volute springs.=
[Illustration: 1454.-1467.]
=1469. Torsional spiral spring.=
=1470. Wire staple torsional spiral spring,= used for hinging; the ends
of the wire are bent at a right angle and driven into the wood.
=1471. Fixed spring.=
=1472 & 1473. Sear springs.=
=1474. Flat spiral spring.=
=1475. Plate spring.=
=1476. Indiarubber spring= for tension.
=1477. Wire spring.=
=1478. Ribbon spring= for torsion.
=1479. Compound rubber disc spring.=
=1480. Air cushion or spring piston.=
=1481. Laminated plate wagon spring.=
=1482. Compound dished disc or bent plate spring.=
=1483. Loop spring.=
=1484. Flat spiral spring, clock spring or coil spring.=
=1485. Split ring spring.=
[Illustration: 1468.-1485.]
=1486. Spring pole= for foot hammer motion, &c.
=1487 to 1489. Spring washers.=
=1490. Spindle-shaped compression spring.=
=1491. Flat spiral spring= for piston rings.
See also Nos. 1729, 630, 1501, 1503, 11, 767, 768; and Section 35
(Elastic Wheels) for other forms of springs and applications of them.
For equalising the tension of a spring, see No. 1592 and 1602.
Section 81.--SAFETY APPLIANCES FOR VARIOUS USES.
FOR HOIST CAGES, &c.
=1492. Cam gear;= operates by gripping the wood guides by a serrated
eccentric cam surface on the breakage of the rope, the cam being pulled
round by a spring which is kept out of action by the tension of the rope
until it breaks.
=1493. Strut or pawl gear;= explains itself.
=1494. Double wedge gear.=
=1495. Governor gear.= The rope attached to the cage drives a governor
acting on a brake or catch which is thrown into action if the cage gains
excessive speed, used in Attwood Beaver’s Patent; American Elevator Co.,
&c.
=1496. Rack and pawl gear.=
=1497. Cross grip lever gear.=
=1498. Safety hook= to prevent accident from overwinding; the projecting
horns ~A A~ strike the edges of the plate ~B~, and throw the shackle ~C~
at top out of gear.
=For hoist doors= the best appliance is an ordinary spring lock opened
only by a key, the doors being provided with springs to close them.
Various automatic doors, revolving shutters, and other devices have
also been tried. A simple and effectual protection is a continuous
open-work screen wound upon a roller at top and bottom of lift, and
attached to the top and bottom of cage and rising and falling with it,
so that the doors into lift are all covered at all times except the
one at which the cage happens to stand.
=Safety valves= (see Section 89). Various automatic alarm signals are
applied to boilers to warn against low water or excessive pressure.
=Automatic valves= and other devices are applied to pumping and steam
engines to prevent running away. See note to Section 41.
[Illustration: 1486.-1498.]
Section 82.--STEAM TRAPS.
To collect and discharge condensed steam from pipes, &c.
=1499. Trap operated by a modified form of ball cock,= which rises as
the box fills with condensed water and opens the discharge valve.
=1500. Effects the same object by a floating basin.= The condensed water
enters the box outside the basin, fills it, and lifts the basin which
closes the discharge outlet; when the box is full the water overflows
into the basin and sinks it, thus opening the outlet valve.
=1501. Trap operated by expansion= of a bent spring which closes the
valve, on the principle that live steam is hotter than the water
condensed from it.
=1502. Tredgold’s trap.= The valve is opened by a simple float.
=1503. Wilson’s trap,= like 1501, is dependent on the different
expansion of a spring under the difference of temperature of the steam
and condensed water. In this case the spring is formed of a steel and
brass plate riveted together.
There are many other forms upon similar principles to the foregoing.
Section 83.--STARTING VALVES.
The valves used for starting steam and other engines are usually merely
of the ordinary screw down or sliding types. See Section 89.
For starting and controlling all other forms of reciprocating cylinder
motors, such as hydraulic lifting cylinders and presses for all
purposes, the ordinary slide valve with either two or three ports is
the common device; also the ordinary three or four way cock. See
Section 89.
=1504. Locke’s 3-way balanced valve,= which is balanced in all
positions. ~A~ is the supply, ~B~ the cylinder branch, and ~C~ exhaust.
=1505. Fenby’s 3-way equilibrium starting valve.= ~A~ supply, ~B~
cylinder branch, ~C~ exhaust.
=1506. Auxiliary valve and pistons= to start large slide valves too
heavy for direct hand power. A 3-way cock is shown as the auxiliary
valve, but a small slide valve or piston valve may be substituted. See
note at foot of Section 93, also Nos. 1740 and 1741.
=1507. Auxiliary valve and bellows= for air, as sometimes used in large
organs to open heavy “pallets.” The small valve ~A~ is opened by the
pressure of the finger on the corresponding key of keyboard, and allows
the pressure of air to enter the small bellows which operates the large
valve ~B~.
=1508. Four plunger valve,= used for double power hydraulic lift
cylinders employing a trunk piston. For the low power the pressure water
acts on both sides of the piston; for the double power it acts only on
the back of piston, the front side being then open to the exhaust.
=1509. A starting valve,= having two ordinary wing or spindle valves,
either of which is lifted by a double cam or wiper on a spindle passing
through a stuffing box on side of valve case. ~A~ supply, ~B~ cylinder
port, ~C~ exhaust.
[Illustration: 1499.-1509.]
=1510 & 1511. Two methods of operating starting valves= for hydraulic
lifting machines. 1510 acts by counter balance weights and a single
rope, each of the weights being heavy enough to move the valve, and 1511
by an endless rope.
=1512. Low pressure starting valve,= used for piston hydraulic cylinders
in which the lifting is performed by the down stroke of the piston rod,
and in lowering, the valve allows the water to pass from above to below
the piston, the water being exhausted from below the piston on its down
stroke when the valve is in the position shown.
=1513. Oscillating valve,= with plunger face kept up by a spring. The
oscillating valve has two ports passing out at opposite ends, through
stuffing boxes, to either end of the cylinder; the inlet is at top and
discharge at bottom.
=1514. Balanced self-acting starting valve,= suitable for large machines
and low pressure. The upper piston is larger than the lower or main
piston, and the space above the upper piston can be put in communication
with the pressure water below it, or the exhaust port by the small
piston valve at top operated by the hand gear; so that the main piston
is operated by the pressure water acting on it.
Section 84.--TOOTHED GEARING.
=1515. Spur gearing.= For construction of teeth see text books.
=1516. Strongest form of spur teeth= for motion in one direction only.
=1517. Half shrouded spur teeth.=
=1518. Whole shrouded spur teeth.=
=1519. Double helical spur teeth,= stronger by 15 per cent. than
straight teeth; work without backlash or noise, and may be half or whole
shrouded; section of tooth on plane of motion is the same as the
ordinary spur teeth (No. 1515).
=1520. Crown wheel and pinion.=
=1521. Long teeth spur wheels or “star” wheels.= Used on roller mangles,
&c., where the centres rise and fall.
[Illustration: 1510.-1521.]
=1522. Plain bevil gear;= shafts at right angles.
=1523. Plain bevil gear;= shafts at acute angles.
=1524. Plain bevil gear;= shafts at obtuse angle.
=1525. Plain bevil gear;= four shafts at right angles.
=1526. Skew bevils;= shafts not in line with one another.
NOTE.--Where the pair are both of same diameter they are called “mitre
wheels.”
=1527. Spur wheel and pinion;= to increase or decrease power and speed
the diameters can be varied to almost any proportion.
=1528. “Screw gear”;= single helical gear.
=1529. Skew spur wheels;= shafts not parallel.
=1530. Dr. Hooke’s gear.= Three or more separate wheels of similar or
dissimilar pitch fixed together so as to divide the pitch and reduce
backlash.
=1531. The same result obtained by two wheels,= one fixed to shaft, the
other loose and forced round by a spring so as to follow the pitch of
the pinion and destroy all backlash.
=1532. Mortise wheel teeth.=
=1533. Mortise wheel teeth;= another method.
NOTE.--Wood teeth are usually one-third thicker than the iron teeth
they gear into.
=1534. Pin wheel and pinion gear.=
=1535. Lantern wheel.=
=1536. Screw gear,= used in place of bevil gear. Shafts at right angles;
teeth at an angle of 45°.
=1537. Variable speed cone gear.=
=1538. Variable speed square gear.=
=1539. Variable speed oval or elliptical gear.=
=1540. Irregular gear.=
=1541. Internal or epicycloidal gear.= See Nos. 550 and 1545.
Used for differential blocks, &c. Note that both wheel and pinion run
in the same direction, and that more teeth are in gear at one time
than with external gear as No. 1527.
[Illustration: 1522.-1541.]
=1542 & 1543. Varieties of “mangle” gear.= The pinion being revolved
continuously in one direction produces a reciprocating motion of the
wheel; the pinion shaft travels from inside the wheel to outside, and
_vice versâ_, by rising and falling in the slot in the frame. See also
No. 423.
=1544. Differential gear.= See Section 31. One wheel has one or more
teeth more than the other; used for counters, &c.
=1545. Moore’s patent differential epicycloidal gear.= The pinion and
wheel are loose on the shaft and eccentric. One wheel has one tooth more
than the other.
=1546. Multiplying bevil gear.= ~A~ is a fixed wheel, the cross ~C~ is
keyed to shaft, ~B~ loose on ditto, ~D~ and ~E~ loose on ~C~; then ~B~
is driven at a speed greater than the shaft in proportion to the
diameters of the gear. See Patent No. 12,696, 1884.
=1547. Double worm gear,= right and left hand threads. Neutralises the
end thrust on shaft. ~A~ and ~B~ may be geared together.
=1548. Pointed gear;= used for light work and for minimum of friction.
=1549. Curved worm gear,= for heavy strains. Several teeth are in gear
at once, but the thread, having a varying section and pitch, is
difficult to cut.
=1550. Antifriction worm gear= (Hawkins’). The wheel has four rollers;
when one pair is nearly out of gear with the worm, the next pair is
coming into gear. This worm is also difficult to cut.
=1551. Crown worm gear.=
=1552. Ball joint mitre gear.=
=1553. Multiplying rack gear.= The upper moving rack is driven at twice
the speed of the spur wheel rod. The lower rack is fixed; used on
planing and printing machines.
=1554 to 1557. Varieties of worm gear,= with straight, hollowed, and
curved teeth; the latter are strongest.
=1558. Worm and rack gear.=
[Illustration: 1542.-1558.]
=1559. Differential worm gear.= The worm gears into two wheels, one
having one tooth more than the other.
See also Sections 40 and 31.
Section 85.--TRANSMISSION OF POWER.
=a. By belt, chain, or rope.= See Sections 3, 66.
=b. By shafting.= See Section 76.
=c. By gearing.= See Sections 84 and 40.
=d. By steam or air= conveyed in pipes (elastic fluids).
=e. By water, glycerine, or oil= conveyed in pipes (non-elastic fluids).
=f. By stiff rods= running over guides.
=g. By wires or ropes= running over guide pulleys--wire rope
transmission. See Section 66.
=h. By electricity= conveyed along wire conductors.
Section 86.--TANKS AND CISTERNS.
=1560. Plan of square tank= of ordinary form; formed of cast iron
flanged plates and wrought iron tie rods, the joints are either made
with rust cement or planed and jointed with tape and red lead.
=1561. Plan of square tank= with rounded angles.
=1562. Circular tank.= No tie rods required.
=1563. Elliptical tank.= Requires tie rods across the flat sides.
=1564. Polygonal tank.= No tie rods required.
=1565. Elevation of square or polygonal tank.=
=1566. Elevation of cylindrical or circular tank.=
=1567 & 1568. Condensing or cooling tanks.= Surface condensers with
sloping trays or tubes.
=1569. Wrought iron tank,= usual section, formed of sheets and ~L~ irons
riveted together.
=1570 & 1571. Circulating or depositing tanks.=
=1572. Boiler saddle tank.=
=1573. Circulating tank= for hot water.
The level of water may be maintained in tanks by either an overflow
pipe or notch, or by a ball cock on the supply pipe. Glass water
gauges can be fixed outside to show the level of the water inside; and
floats are used, attached to a cord and pulleys, for the same purpose.
See also No. 1730.
Section 87.--THROWING IN AND OUT OF GEAR.
=1574. The driving wheel= is loose on shaft, and is locked to its shaft
by the hand wheel nut (see No. 945), or by a ratchet wheel and locking
pawl.
=1575. Two half-nuts= are lifted in or out of gear with the screw by cam
or lever motion. See No. 942.
=1576. One shaft runs in eccentric bearings,= which can be revolved so
as to throw it out of gear with the other shaft.
[Illustration: 1559.-1576.]
=1577. Radius bar and slot.= The stud wheel can be shifted in or out of
gear along the slot.
=1578. Sliding back shaft,= slides out of gear. See dotted lines.
=1579. Method of throwing a pulley out of gear= by slacking the belt.
This is done either by a cam bearing or sliding motion to the driver
shaft. Works best vertically. See also No. 1219.
=1580. Cam slot motion= for back shaft. To throw it in or out of gear.
=1581. Motion employed for punching machines,= &c. To set the punch in
or out of action by a cam and hand lever.
Section 88.--VARIABLE MOTION AND VARIABLE POWER.
=For variable speed and power= by spur gear, see Sections 84 and 40.
=For variable speed and power= by bevil gear, see Section 84.
=For variable speed and power= by cam gear, see Section 9.
=For variable speed and power= by belt gear, see Section 3.
=1582. Variable speed belt cones,= for crossed belts. Angle of cones
should not exceed 15°.
=1583. Stepped cone gear.=
=1584. Variable throw crank pin.= (See Hastie’s Patent, 3561, 1878;
Knowelden and Edwards’, 2996, 1858.)
=1585. Beam motion,= with variable fulcrum to alter the proportionate
lengths of stroke of driving and driven cylinders. See also No. 1606.
=1586. Variable pressure accumulator.= Both cylinders are in
communication by a pipe, and the pressure varies with the angle between
the rams.
=1587. Wright’s variable gear.= The radius of frictional contact of the
wheels varies as they are moved closer together or separated.
=1588. Olmsted’s variable cone friction gear,= with intermediate double
cone idle wheel instead of belt.
=1589. Convex and concave cones= for _open_ belts.
=1590. Three speed gear,= each separate pair of spur gear being driven
by its own belt pulley on separate sleeve pieces.
=1591. Irregular or elliptical gear.=
=1592. Lever combination= to obtain an even tension from a spring
throughout its motion.
[Illustration: 1577.-1592.]
=1593. Scroll spur gear.=
=1594. Scroll gear= for obtaining a variable pull from a weight.
=1595. Variable friction gear.= The pinion can be moved up or down from
the centre to the outside of disc to vary the speed.
=1596. Owen’s compound lever variable pressure air pumps.= The pressure
increasing and speed decreasing as the pistons rise to the top of their
stroke.
=1597. 2-speed gear= by one belt. One loose pulley ~B~ carries a
transverse mitre wheel, which, gearing into the fixed mitre wheel ~A~,
drives the mitre wheel pulley ~C~ keyed to shaft at twice the speed of
pulley ~B~ when the belt is on ~B~; by shifting the belt to pulley ~C~,
the speed is 1 to 1. The third pulley is loose for running idle.
=1598. 2-speed bevel gear= with three wheels and sliding shaft, by which
either pair can be put into gear.
=1599. 2-speed bevel gear= with four wheels and sliding shaft.
=1600. Increasing speed cone and screw,= friction gear. The cone is
driven by frictional contact with the pinion.
=1601. Variable fulcrum lever,= with shifting pin and hole adjustment.
=1602. Fusee barrel,= as used in clocks and watches to equalise the
tension of spring on the movement; may also be employed to give a
variable speed. The spring is usually similar to No. 1484, and coiled in
the upper barrel.
=1603. Variable throw crank pin and slot,= much used for variable feed
motions in combination with some type of pawl and ratchet gear.
=1604. Variable travel imparted to the piston rod from the crank= by
altering the point of attachment of the link ~A~ to the slot.
=1605. Variable power pistons,= single-acting.
=1606. Effects the same ends as No. 1601 or 1585,= by shifting the
fulcrum point along the slot by means of a screw.
[Illustration: 1593.-1606.]
=1607. Variable throw crank pin= by means of a jointed crank and radial
adjusting screw.
=1608. Variable throw crank pin= by attaching the crank pin to an
eccentric disc. See Section 10.
=1609. Wind motor-fan or turbine,= with variable-angle vanes actuated by
a central sleeve and cam or lever gear.
=1610. Variable friction cone gear;= the small friction pinion can be
moved radially to and fro to alter the leverage and consequently speed
of driving radius from the cone.
In the steam engine, compressed air engine, and gas engine (these
being all elastic fluids), the power given out is varied by altering
the supply of steam, air, or gas. In the water wheel the power may be
varied by altering the quantity of water (or head of water) supplied
to the wheel. In the turbine the power can be varied by altering the
head of supply water and the angle of vanes; altering the quantity
reduces the speed and efficiency. The turbine will not work well under
great variations of either head or quantity.
See also Nos. 736, 722, 723, 1190, 1191, 381, 382, 384, 385, 377, 372,
373; and Sections 20 and 40.
For variable pressure or tension by springs, see Section 80.
Variable balance weights, Section 20.
Section 89.--VALVES AND COCKS.
Of the almost innumerable varieties of valves and cocks in use the
following are selected as types without reference to special uses, each
type having its peculiar value, and the drawings are only intended to
indicate the special features of each type without such details as may
be varied to suit each particular requirement or application.
=1611. The common plug cock.=
=1612. The same,= but with screwed gland.
=1613. 2-way or 3-way plug cock,= with packed gland.
=1614. Hollow plug blow-off cock,= with packed gland.
=1615. Back pressure or check valve,= self closing.
=1616. Ball valve and guard,= self closing.
=1617. Indiarubber disc and grating valve.=
=1618. Double flap indiarubber or leather= and grating valve.
=1619. Simple flap valve= faced with rubber or leather.
=1620. Rocking or rolling valve.= For opening and closing gradually and
easily against pressure.
=1621. Roll-up valve.= For same purposes as the last named.
[Illustration: 1607.-1621.]
=1622. Sector full-way screw down valve,= shown closed; when open the
disc is up in the chamber out of the waterway.
=1623. Double face valve;= the spindle is screwed into the stuffing-box
neck and the lower valve, the upper one being pinned to the spindle; the
thread in the lower valve is twice the pitch of the upper thread.
=1624 & 1625. Spring relief valves;= the springs are adjusted to blow
off at any stated pressure, which may be regulated by a screw or nut
(not shown).
=1626. Weighted lever relief valve or safety valve.=
=1627. Reducing valve,= can be adjusted by the balance weight to pass
fluids from a high pressure to any lower pressure.
=1628. Another form,= with spring balance adjustment and equilibrium
valve.
=1629. Equilibrium valve.=
=1630. Equilibrium valve,= not steam tight, but serrated, to cut off
gradually, employed for governors of steam engines.
=1631. Equilibrium cylindrical grating valve,= may be used to open and
close either by vertical or revolving motion.
=1632. Common throttle or butterfly valve.=
=1633. Duplex throttle or damper= for a three-way pipe or flue.
[Illustration: 1622.-1633.]
=1634. Hydraulic high-pressure check valve,= with long guide wings.
=1635. Hydraulic plug or spindle valve and seating;= all seatings for
high pressure should be narrow and hard.
=1636. Duplex or Ramsbottom safety valve;= each valve serves as a
fulcrum by which to lift the other. One fulcrum point should be jointed
to the lever and the latter move in a vertical guide, or else the point
of attachment of the spring to the lever be placed below the level of
the valve seatings.
=1637. A modification of the last named.=
=1638. Pass valve,= used for pneumatic despatch tubes.
=1639. Oscillating lever duplex valve.=
=1640. Simple radial disc valve or sluice.=
=1641 & 1642. Oscillating cylindrical valves.= Corliss valves; sometimes
made tapered or conical.
=1643. Multiple ball valve,= for high lift delivery valve of large
pumping engines. Balls are of guttapercha, and open and close without
shock.
=1644. Multiple ring valve.= The rings open and close in succession,
thus avoiding shocks.
=1645. Double beat ring valve.=
=1646. Double beat equilibrium or Cornish valve.= The upper seating can
be made of such area as to partly or entirely balance the valve.
=1647. Multiple ring valve.= The indiarubber rings expand and contract
over the perforations.
[Illustration: 1634.-1647.]
=1648. Double-beat valve,= with sunk seating.
=1649. Common ~D~ slide valve,= with three ports.
=1650. Duplex or double ~D~ slide.=
=1651. Another form,= partly in equilibrium.
=1652. Equilibrium slide valve,= with circular packed trunk on back, of
area sufficient to balance the face area of valve.
=1653. Similar result= obtained by a piston and link.
=1654. Equilibrium piston valve= employed in lieu of the slide valve.
~A~ steam pipe, ~B B~ exhaust.
=1655. Gridiron slide valve.=
=1656. Common plate slide valve or sluice,= used for blast pipes.
=1657. Floating ball valve,= for automatic discharge of air from water
mains.
=1658. Ordinary double-faced sluice valve,= lifts clear of the water
way.
[Illustration: 1648.-1658.]
=1659. Single face sluice valve,= for sewage water, &c.
=1660. Flap sluice valve.= Tidal outlet valve.
=1661. Diaphragm valve.=
=1662. Oscillating disc valve,= for gas.
=1663. Large 3 or 4-way plug cock.=
=1664. Finger valve,= closed by a spring.
=1665. Taper cone valve,= for gradually closing an outlet.
=1666. Dome valve,= used for hot blast, hot gases, &c. This form retains
its shape when heated, expanding evenly.
=1667. Common floating ball tap.=
=1668. Three-way air valve.=
=1669. Duplex slide,= used to close a number of openings at once.
=1670. West’s spiral valve,= with indiarubber cord which expands and
contracts over a spiral perforated groove.
=1671. Dennis’ self-lifting valve.= The valve is kept to its seat by the
pressure being admitted on to its back through small hole ~A~; when the
larger hole ~B~ is opened by the spindle the back pressure is relieved
and the valve lifted by the pressure below its conical underside.
=1672. Common cone plug.=
[Illustration: 1659.-1672.]
=1673. Equilibrium plug or cylindrical valve,= double ported.
=1674. Another form of self-lifting valve.= See No. 1671 for
description.
=1675. Compound flap valve.=
=1676. Indiarubber pump valve.=
=1677. Venetian shutter or compound butterfly valve.=
=1678. Bye pass= used to allow a small flow when the main valve is shut
off. Used also to equalise pressure on both sides of a large valve to
enable it to open easily.
=1679. Bell and hopper, or cup and cone;= used for blast furnaces, coke
ovens, and gas generators.
=1680. Cup valve and suspended weight.=
=1681. Four-way valve= for hot water pipes, &c.
=1682. Oscillating valve.=
=1683. Gas purifier centre valve, for four purifiers;= to work one
purifier off and three on, or all four on at once. It is similar in plan
to No. 1684, but has an additional top valve which allows the gas to
pass into the fourth purifier; the top valve has an independent sleeve
and lever motion.
=1684. Gas purifier centre valve,= employed to deliver and discharge gas
into and out of any one, two, or three out of four purifiers. The motion
of the gas is shown by the arrows.
=1685. Conical grating valve= with radial slots, opened or closed by
revolving motion.
Section 90.--WATER WHEELS AND TURBINES.
=1686. Simple undershot wheel.=
=1687. Breast wheel.=
[Illustration: 1673.-1687.]
=1688. High breast wheel.=
=1689. Overshot wheel.=
=1690. Return overshot wheel.=
=1691. Internal feed re-action wheel.=
=1692. Sunk wheel,= driven by air: may be used as a meter for gas or
air.
=1693. Current wheel,= driven by tidal or river current.
=1694. Flutter wheel,= with high fall.
=1695. Horizontal wheel.=
=1696. Re-action wheel,= the oldest form of turbine.
=1697. Engel’s diagonal wheel.=
=1698. Scoop wheel= for raising water. See also No. 1024.
=1699. Wheel, with internal buckets= and feed.
_Note_ that most of these may be reversed and made into water raising
machines, as No. 1698.
=1700 to 1703. Sections of various forms of buckets= in wood and iron.
No. 1703 is a ventilated bucket which allows air to escape as the water
enters.
For governing speed of water wheels and turbines, see Section 41.
=1704. Fourneyron’s turbine,= outward flow; the outer vanes are fixed,
the inner ones revolve with the shaft.
=1705. Jonval’s turbine,= downward flow; either the upper or lower set
is fixed.
=1706. Swain’s turbine,= inward and downward flow, with inward curved
vanes or flumes.
[Illustration: 1688.-1706.]
=1707. Leffel’s turbine,= inward and downward flow; has one outer ring
of fixed vanes and two inner sets revolving, but having different angles
of flow.
=1708. Undershot jet wheel= for high pressure water.
Many other forms of turbines are extant, but are mostly modifications
of the above types. The best types have means of varying the angle of
the vanes and areas of passages to suit varying quantities of water.
Section 91.--WHEELS IN SEGMENTS.
=1709. Heavy gearing= for rolling mills, &c., with dovetailed joints
wedged and packed.
=1710. Wheel cast in sectors= bolted together.
=1711. Bevil wheel in halves.=
=1712. Wheel with rim in segments= bolted together, and provided with
bored and cottered sockets for arms in both rim and boss.
=1713. Fly wheel rim,= cottered and dowelled together.
=1714. Arms and boss cast in one:= the rim in segments, bolted together
and to the arms.
=1715. Tension wheel.= The tie spokes are sometimes arranged in two sets
at a slight angle to each other to prevent the rim turning without the
boss. Bicycle wheels are of this class.
=1716. Wrought-iron wheel,= with cast boss.
=1717. Wrought-iron wheel,= with cast boss.
=1718. Rim in segments= bolted together, wood arms and cast boss, with
sockets to receive arms; this type is much used for water wheels.
[Illustration: 1707.-1718.]
=1719. Railway wheel:= boss of cast iron with wrought-iron arms cast in.
The rim is of rolled iron or steel riveted on. There are numerous
methods of fastening the tyres to arms, detailed in the _Engineer_, July
23rd, 1880.
=1720. Spring rim split pulley.=
=1721. Segment fly-wheel,= with long radial bolts to secure the rim,
arms, and boss together.
=1722. Large centre boss,= with rim segments bolted to it.
=1723. Wheel in halves;= the boss is held together by two bolts acting
as cotters.
Section 92.--WEIGHING, MEASURING, INDICATING PRESSURES, etc.
=1724. Weighing by a beam with equal arms.= Weights ~A~ = package ~B~.
=1725. Weighing by a beam with unequal arms.= Weight ~A~ constant;
leverage of ditto variable by shifting it along the graduated arm of
lever.
=1726. Graduated measuring vessel.=
=1727. Similar principle applied by compound levers with unequal arms.=
The table is supported on four points on the arms of levers loosely
jointed together in the centre; one lever is extended and coupled by a
rod to a graduated lever with sliding weight. Knife edges are used for
bearings for all weighing machines by leverage. See No. 958. This
construction is the basis of most of the ordinary weighing machines in
use.
=1728. Duckham’s patent hydraulic weighing machine.= The article to be
weighed is suspended from the hook, and exerts a pressure on the ram.
The corresponding pressure on the liquid (usually oil or glycerine) is
indicated on the pressure gauge, which is graduated to show the weight.
=1729. Spring balance.=
=1730. Appliance for indicating depth of water= in a cistern by an air
bell and pipe connected to a ~U~ water gauge. The pressure on the air in
the bell varies with the depth or head of water above it, and is
indicated on the gauge. A modification of this is employed for sounding
at sea.
Weights of substances may be ascertained by their displacement in
water or mercury, or by supporting the weighing scale on a free piston
resting on an ascertained area of water or mercury, the pressure
produced being indicated by a gauge.
=1731. Micrometer gauge.=
=1732. Radial arm weighing machine.=
=1733. Small weighing device,= depending upon the angle the card assumes
in respect of the vertical pointer, which is on a free pivot.
=1734. Automatic measuring or weighing device.= The material fills one
compartment until it overbalances, when it falls and empties itself; the
material then fills the other compartment, and so on.
[Illustration: 1719.-1734.]
=1735. Wet gas meter.= The gas enters at the centre, and as the
compartments fill they rise out of the water, the gas being discharged
at the outer ports into the casing.
=1736. Measuring wheel.=
=1737. Measuring wheel.=
=1738. Double slide measurer.=
=1739. Automatic tipping scale.= When full, to equal the weight, it
falls and tips by striking a fixed stop; the scale then turns over and
returns to its position, and is refilled.
=1740. An ordinary piston and cylinder= are often employed to measure
liquids, and fitted with a reversing valve on the same principle as Nos.
1026, 1027, and 1741. See also note to Sec. 93.
Most of the rotary devices (see Section 75) have been employed as
meters for liquids and gases. See No. 1692.
Dry gas meters usually employ an expanding bellows, or light piston,
with a self-reversing valve, similar to Nos. 1299 and 1026. See also
Section 44.
Section 93.--WATER-PRESSURE ENGINES.
See also Section 56.
Hydraulic ram. See No. 1025.
Robinet. See No. 1026.
Two- or three-cylinder engines, with slide valves operated either by
eccentrics as in the steam engine, or by the oscillation of the
cylinder. The slide valves have no lap or lead; there is no cushioning
except what is given by an air vessel on the supply pipe. Three-cylinder
engines are usually made single acting with rams. See No. 1743.
=1741. Single cylinder engines.= These must have the slide or other
distributing valve reversed by pistons ~A~, ~A~, operated by the
pressure of the supply water. This is usually done by an auxiliary valve
~B~, reversed by the main piston rod ~C~. This valve admits the pressure
water to the pistons ~A~, ~A~, which reverse the main slide valve. See
No. 1506. See note below.
=1742. Mode of working an underground pumping engine= by water cylinders
above ground, connected to those below by pipes ~A~, ~A~. ~B~ is the
suction, ~C~ the delivery.
=1743. One, two, or three cylinder water engine.= The ports are in the
segmental base of the cylinder, have no lap, and are opened and closed
by the oscillation of the cylinder.
=1744. Circular oscillating cylinder,= in a case which opens and closes
its ports by its own oscillation.
In lieu of the weighted lever valve gear for single cylinder water
pressure engines, the engine may be arranged to compress a spring
during the stroke, which at the end of the stroke shall be released,
and by its expansion reverse the valve.
Section 94.--WASHING.
=1745. Cylindrical revolving screen washer,= for roots, &c.
=1746. Tub and paddle washer.=
[Illustration: 1735.-1746.]
=1747. Coal washer.= The water is kept in motion up and down through the
screen ~A~ by a cylinder and piston ~B~; the mud sinks to ~C~ and the
washed coal passes over to ~D~. Both are removed continuously by
elevators or worms. See Section 57.
For washing ores sloping screens either plain or perforated are often
used, a stream of water being kept flowing over the ore, which is kept
in motion. See Nos. 1266 and 477, also Cylindrical Revolving Screens,
as No. 1262.
=1748. Cylindrical perforated drum,= with internal fixed spiral flange
which causes the material to travel at a fixed rate of motion. The
cylinder may be revolved in a water trough as No. 1745, or water may be
fed in with the material and the casing be unperforated.
=1749. A contrivance to keep a continuous circulation= in a boiling tub
or copper in which clothes, &c., are washed. The hot water from the
bottom rises up the tin tube, and is discharged on the surface.
=1750. Corrugated rollers washing device, for fabrics.=
=1751. Water trough and dipping band,= for washing cloths, wool, paper,
&c.
Domestic washers comprise, besides the ordinary tub and dolly, washing
boards, having corrugated surfaces; rocking and revolving boxes,
having a churn-like motion. Brushes also are sometimes used.
Section 95.--WINDMILLS AND FEATHERING WHEELS.
=1752. Feathering paddle wheel.= Each float has a bracket and pin at
back, with connecting rod to a common eccentric (fixed), through which
the shaft revolves.
=1753. Spiral vane or cowl,= for chimney top. Used to drive a vertical
worm inside the chimney cap to maintain an upward draught, by employing
the wind as a motive power.
=1754. Windmill sails,= with angular adjustment by a sliding device on
the shaft.
=1755. Feathering horizontal windmill.= Each float is hinged a little
out of centre to the arms, so that the pressure of wind (see arrow)
turns the floats to the positions in the sketch as they revolve.
=1756. Hollow semi-spherical cup windmill= or motor.
=1757. Wind motor,= with curved vanes. These last two revolve in the
direction of the arrows, because the wind has more hold upon the hollow
sides of the cups and vanes than on the convex side.
=1758. Self-feathering wind wheel.=
=1759. Spiral wind wheel.=
[Illustration: 1747.-1759.]
Section 96.--WINDING APPARATUS.
=1760. Barrel or drum,= for wire, &c.
=1761. Winding barrel,= for cranes, winches, &c.
=1762. Fusee barrel.= See No. 1602.
=1763. Grooved barrel,= for chain. Prevents the chain riding as it
coils.
=1764. Hexagon frame winder,= for yarn, &c.
=1765. Spool.=
=1766. Card winder.=
=1767 & 1768. Bobbins.= There are a great many patterns in use for
various trades.
=1769. Appliance for winding bobbins= of cotton, and other machinery.
The bobbin is stationary and the flyer revolves, the thread passing up
its centre and down one arm through the eye, which has an up and down
feed motion to wind the thread on evenly.
=1770. Mode of feeding the thread= on to the spindles to cause it to
coil evenly by an oscillating arm and pin over which the thread passes.
=1771. Drum,= for flat rope or chain wound upon itself.
For winding engines and winches, see Nos. 1222 to 1226.
See also Rope Gear, Section 66.
Section 97.--HANDLES, &c., FOR VARIOUS PURPOSES.
=1772. Knob handle.=
=1773. Loop handle,= hinged.
=1774. Loop handle,= fixed.
=1775. ~T~ handle.=
=1776. Plain handle.=
=1777. Sash lift= or drawer handle.
=1778. Hand bar.=
=1779. Swing door handle.=
=1780. Sunk or flush loop handle.=
=1781. Hinged lifting levers.=
=1782. Bent handle,= for radial motion.
[Illustration: 1760.-1782.]
=1783. Hand wheel.=
=1784. Cranked ~T~ handle.=
=1785. Capstan wheel.=
=1786. Bow or lifting handle,= for ladles, buckets, &c.
=1787. ~T~ bar handle,= for two hands.
=1788. Cross hand lever,= four, six, or eight arms.
=1789. Loop handle,= sometimes cast into a casting.
=1790. Ring handle.=
=1791. Double bar pushing handles.=
=1792. Bent handle,= for radial motion.
=1793. Weighted handle.=
=1794. Vice handle,= with sliding lever bar.
=1795. Hand bar,= with forked lever attachment for pumps, &c.
=1796. ~S~ lever double cranked handle.=
=1797. Stirrup handle.=
=1798. ~T~ lifting handle or key,= for opening flush doors or manhole
covers.
=1799. Thumb screw head.=
=1800. Straight handle,= with suspending eye.
=1801. Capstan wheel,= for screw gear.
=1802. Ventilated twisted handle.=
=1803 & 1804. Loop handles.=
[Illustration: 1783.-1803.]
=1805. Spring lock lever handle.=
=1806. “Coffee pot” handle.=
See also Section 48.
Section 98.--APPARATUS FOR DRAWING CURVES.
See Gearing, Section 40; Ellipsograph, Section 34.
=1807. Cyclograph,= for describing arcs, the chord and versed sine being
given. Fix pins at ~A~ and ~B~, fasten together at ~C~ two slips of
wood, hold the pencil at ~D~, and move the slips round, keeping them
against the pins. See also No. 11.
=1808. Hyperbolagraph.= Height and focus are given as for 1809, and
string fixed to ~B~, and focus ~A~; the arm is pivoted at ~C~, and the
pencil used as described for No. 1809.
=1809. Parabolagraph.= The height of parabolic curve ~H~ and focus ~A~
are given. A string is fastened to end of set square at ~B~, reaching to
~C~, and the other end fixed to a pin in the focus ~A~. A pencil held in
the loop and kept against edge of set square as it is moved to left or
right will describe the parabolic curve.
=1810. Cycloidograph,= describes the hypo- or epi-cycloid. A
modification of this is used to draw the curves of the teeth of wheels.
=Pentagraph,= for reducing or enlarging outline drawings, No. 1924.
=Helicograph,= to describe a regular helix by a central fixed bevil
wheel which drives the radial bevil wheel screw and scribing pencil,
No. 1925.
=A simple helicograph,= with radial screw and roller nut, which
travels along the screw as the apparatus is revolved on its centre
pin, No. 1926.
Section 99.--MATERIALS EMPLOYED IN CONSTRUCTION
The following memoranda relate only to such materials as are required in
connection with machinery or mechanical constructions, and are intended
to supply particulars of the dimensions of the manufactured or raw
material, giving the sections manufactured and the limits as to size
available for incorporation in any design under consideration.
=Rolled iron and steel bars= are manufactured as below:--
=1811. Rounds,= from ³⁄₁₆″ to 7³⁄₄″ diameter, and up to 18′ long.
=1812. Squares,= from ³⁄₁₆″ to 6″ square, and up to 18′ long.
=1813. Flats,= from ¹⁄₂″ to 14″ wide, and up to 18′ long.
=1814, 1815, 1816, 1817, 1818, & 1819. ~L~ iron sections= are made from
³⁄₄″ × ³⁄₄″ up to 14″ × 3³⁄₄″, or to 12¹⁄₂″ united inches, with equal or
unequal flanges, and up to 30′ long; but the acute, obtuse, and round
angled sections are not usually stocked.
=1820 & 1821. ~T~ irons,= from 1″ × 1″ up to 12 united inches, or to 9″
× 4″, and up to 30′ long.
=1822. Rolled girder iron,= from 3″ deep to 20″ deep × 10″ flanges, and
to 36′ long, in hundreds of sections.
=1823. Zore girders,= from 3″ to 8″ deep, and to 24′ long.
=1824. Channel iron,= from ³⁄₄″ to 12″ wide, and to 25′ long.
=1825. Convex iron,= from 1″ to 6″ wide, and up to 20′ long.
=1826. Cope iron,= from 1″ to 4″ wide, and to 20′ long.
[Illustration: 1804.-1826.]
=1827. Half-round iron,= from ¹⁄₂″ to 4″ wide, and to 20′ long.
=1828. Funnel ring iron,= from 3¹⁄₂″ × ³⁄₁₆″ to 8″ × ⁹⁄₁₆″ wide, and up
to 18′ long.
=1829. Jackstay iron.=
=1830. Hollow cope iron.=
=1831, 1832, & 1838. Rail sections= (see Section 73), usually made in
18′ to 30′ lengths, and numerous sections of from 22 lbs. to 84 lbs. per
yard.
=1833. Bulb ~L~ iron.=
=1834. Deck beam or bulb ~T~ iron,= up to 16″ × 6″.
=1835. Bulb ~L~ iron,= up to 10″ × 4″.
=1836. Bulb iron,= to 13″ wide.
=1837. Pile iron.=
=1839, 1840, & 1841. Flush tram rails,= 18′ to 30′ long.
=1842, 1843, & 1849. Fire bar iron.=
=1844. Double ~L~ iron,= ¹⁄₂″ × 1″ × ¹⁄₂″ to 5″ × 5″ × ¹⁄₂″.
=1845. Cross iron.=
=1846, 1847, & 1853. Sash bar iron.= Hundreds of special sections are
manufactured.
=1848. Bevil edge iron.=
=1850. Octagon bar iron.=
=1851. Hexagon bar iron.=
=1852. Tyre iron,= made in many sections. See note to No. 1719.
[Illustration: 1827.-1853.]
=1855. Bevilled flat iron.=
=1856. Trough iron.= Used for bridge flooring, fire-proof floors, &c.
=1857. Double convex iron.=
=1858 & 1859. Tramplate iron.=
=1860 & 1861. Chair or sleeper iron.=
=1862. Oval iron.=
=1863, 1864, & 1865. Round edged flats.=
=1866. Segment round iron.=
=1867. Round edged convex iron.=
=1868. Bevilled flat iron.=
=1869. Bevil edge flat iron.=
=1870. Bevilled flat iron.=
=1871. Round edged hollow convex iron.=
=1872. Taper edged hollow convex iron.=
=1873. Boiler tube expansion ring iron.=
=1874. Moulded flat bar.=
In addition to the above, iron ornamental mouldings are rolled with
moulded and relief ornaments in bars, from ⁵⁄₈″ to 2³⁄₄″ wide, and up
to 16′ or 18′ long. Also plain mouldings similar in sections to those
used in joinery.
=Plates= (iron and steel) are manufactured from ¹⁄₈″ to ³⁄₄″ thick
ordinary. Thicker plates are rolled to order up to 20″ thick.
Stocked sizes of ordinary plates are 4′ × 2′ up to 14′ × 4′ 6″.
=Strips= from 7″ to 22″ wide, and up to 30′ long.
=Chequered plates,= with diamond, oval or square recessed patterns,
are made 6′ × 2′ up to 8′ × 3′ 6″.
=Sheets,= plain, in thicknesses from No. 10 w.g. to No. 36 w.g., and
from 6′ × 2′ to 10′ × 4′.
Corrugated sheets, plain or galvanised, from No. 16 to No. 26 w.g.,
and from 6′ × 2′ to 9′ × 2′.
Tinned sheets, same as above.
Cold rolled sheets, same as above.
Planished sheets, same as above.
Lead-coated sheets, same as above.
Tin plates, terne plates, 14″ × 20″, 17″ × 12¹⁄₂″, 15″ × 11″, 14″ ×
10″, 24″ × 20″, 28″ × 10″, 28″ × 20″.
Hoops, from ⁵⁄₈″ to 7″ wide, and from No. 8 to No. 24 w.g.
=1875. Wire; sections manufactured= in hard iron, soft iron, soft steel,
hard steel, tempered steel, piano wire, covered wire (wound with either
cotton, silk, guttapercha, flax, &c.), or copper wire. Also brass,
copper, lead, zinc, and other metal wire, hard or soft; tinned iron
wire, galvanised iron wire, tinned brass wire, coppered iron wire,
lead-coated iron wire.
[Illustration: 1854.-1875.]
=Pipes= (see Section 57) =and tubes= of wrought iron, either butt or
lap welded, or solid drawn, are made in four qualities or
strengths:--1. Gas tube; 2. Steam or water tube; 3. Boiler flue tube;
4. Hydraulic tube. These are manufactured from ¹⁄₄″ to 3″ internal
diameters; boiler flue tubes to 9″ diameter, but much larger sizes can
be made to order.
Solid drawn steel tubes are made up to 10″ diameter; larger sizes are
made to order.
Special steel or wrought iron pipes, flanged with ~L~ iron, are made
up to 4′ diameter with welded joints, and welded steel or wrought iron
socket and spigot pipes up to 24″ diameter.
=Cast iron pipes= are made in the following strengths:--Rainwater
pipes, hot-water pipes, gas mains, water mains, hydraulic mains for
high pressure, and the thicknesses of metal vary according to the
pressures. Diameters from 1¹⁄₂″ up to 4′, and lengths usually 6′ and
9′. See Section 57.
=Castings= are made in cast iron of various mixtures, according to
strength, toughness, or hardness required, and of any weight up to 20
tons. Chilled iron castings are made for hard wear, as in crusher
rolls, &c., but cannot be machined; they are usually ground smooth by
a grindstone or emery wheel.
=Steel castings= are made in either Bessemer, Siemens-Martin,
Thomas-Gilchrist, or in crucible steel, the latter being most relied
upon. They require annealing to soften them sufficiently for
machining, are almost invariably “blown” or honeycombed, and rarely
homogeneous, or twice alike from the same pattern or cast.
=Wrought-iron castings,= Mitis metal, &c., are also obtainable, but
malleable cast iron castings are most relied upon for toughness, the
process having now attained great perfection, but is not applicable to
very thick castings.
Pressed iron on steel forgings of simple forms are now obtainable at
low prices.
=Forgings= in wrought iron and steel can now be made to almost any
size, shape, and weight, and are replacing many structures formerly
made of cast iron or built up.
=Other metals= employed are copper, brass, tin, zinc, phosphor-bronze,
lead, antimony, bismuth, pewter, Muntz metal, aluminium, sodium,
potassium, platinum, gold, silver, nickel, and a great variety of the
bronzes, which are valuable compounds varying in tenacity and hardness
from the hardest steel to that of soft copper. Most of the above are
manufactured into wire, sheets, tubes, rods, &c., and can in addition
be cast into any form from a crucible. Copper can be forged but not
welded; joints in it are generally brazed or soldered.
=Other materials= employed comprise--
=Timber.= Yellow, white, and red pine in logs, deals, and battens;
logs, up to about 3′ diameter by 35′ to 40′ long; deals, 9″, 10″, and
11″ wide, and from 1¹⁄₂″ to 4″ thick--a few wide deals are imported up
to 22″ wide--spruce and fir, sycamore, pear tree, willow, poplar, &c.
The following table gives a list of woods and their applications:--
TABULAR STATEMENT OF THE WOODS COMMONLY IN USE IN GREAT BRITAIN.
FOR BUILDING.
_Ship-building._--Cedars, deals, elms, firs, larches, locust, oaks, &c.,
&c.
_Wet works, as piles, foundations, &c._--Alder, beech, elm, oak,
plane-tree, white cedar.
_House carpentry._--Deals, oaks, pines, sweet chestnut.
FOR MACHINERY AND MILL-WORK.
_Frames, &c._--Ash, beech, birch, deals, elm, mahogany, oak, pines.
_Rollers, &c._--Box, lignum vitæ, mahogany.
_Teeth of wheels, &c._--Crab-tree, hornbeam, locust.
_Foundry patterns._--Alder, deal, mahogany, pine.
FOR TURNERY.
_Common wood for toys (softest)._--Alder, beech (small), birch (small),
sallow, willow.
_Best woods for Tunbridge ware._--Holly, horse chestnut, sycamore (white
woods); apple-tree, pear-tree, plum-tree (brown woods).
_Hardest English woods._--Beech (large), box, elm, oak, walnut.
FOR FURNITURE.
_Common furniture and inside works._--Beech, birch, cedars, cherry-tree,
deal, pines.
_Best furniture._--Amboyna, black ebony, cherry-tree, Coromandel,
mahogany, maple, oak (various kinds), rose-wood, satin-wood,
sandal-wood, sweet chestnut, sweet cedar, tulip-wood, walnut,
zebra-wood.
_Foreign hard woods, several of which are only used for ornamental
turnery._--
1. Amboyna. 13. Greenheart. 25. Peruvian.
2. Beef-wood. 14. Grenadillo. 26. Princes-wood.
3. Black Bot. B. wood. 15. Iron-wood. 27. Purple-wood.
4. Black ebony. 16. King-wood. 28. Red sanders.
5. Box-wood. 17. Lignum vitæ. 29. Rosetta.
6. Brazil-wood. 18. Locust. 30. Rose-wood.
7. Braziletto. 19. Mahogany. 31. Sandal-wood.
8. Bullet-wood. 20. Maple. 32. Satin-wood.
9. Cam-wood. 21. Mustaiba. 33. Snake-wood.
10. Cocoa-wood. 22. Olive-tree & root. 34. Tulip-wood.
11. Coromandel. 23. Palmyra. 35. Yacca-wood.
12. Green ebony. 24. Partridge-wood. 36. Zebra-wood.
Nos. 3, 8, 16, 33, and 34 are frequently scarce.
Nos. 3, 5, 8, 9, 10 are generally close, hard, even tinted, and the
more proper for eccentric turning, but others may also be employed.
Nos. 4, 5, 10, 12, 14, 17, 18, 19, 30, 32 are generally abundant and
extensively used. All the woods may be used for plain turning.
MISCELLANEOUS PROPERTIES.
_Elasticity._--Ash, hazel, hickory, lance-wood, sweet chestnut
(small), snake-wood, yew.
_Inelasticity and toughness._--Beech, elm, lignum vitæ, oak, walnut.
_Even grain, proper for carving._--Lime-tree, pear-tree, pine.
_Durability in dry works._--Cedar, oak, poplar, sweet chestnut, yellow
deal.
_Colouring matter_ (_red dyes_).--Brazil, braziletto, cam-wood,
log-wood Nicaragua, red sanders, sapan-wood.
_Colouring matter_ (_green dye_).--Green ebony.
_Colouring matter_ (_yellow dyes_).--Fustic, zantes.
_Scent._--Camphor wood, cedar, rose-wood, sandal-wood, satin-wood,
sassafras.
=Indiarubber,= manufactured into sheets, with or without canvas
insertion of single, double, or treble thickness, up to 36″ wide and to
¹⁄₂″ thick; cord to 1″ diameter; tubes, plain, or with canvas insertion
or wire coiled inside or outside, from ¹⁄₄″ to 4″ bore, usually in 30′
and 60′ lengths. Washers, rings, rollers, strips, belts, and moulded
articles of every form.
=Guttapercha= is manufactured into similar articles.
=Leather.= Most of the varieties are manufactured from the skins of
oxen, sheep, goats, deer, horses, dogs, hogs, and seals, and the larger
skins are divided into butts, shoulders, cheeks, and bellies, the
dimensions depending of course upon the size of the animals. Ox hides
are the largest and kid skins the smallest in general use.
For mechanical purposes ox hide, raw or tanned, is chiefly used, as
for valves, seatings, belts, piston leathers, &c. Sheep skins can be
obtained either strained, half-strained, or unstrained; the first are
hard and comparatively stiff, the last-named soft and pliable as
cloth. Other soft varieties are goats’ skins and chamois leather.
There are many imitations of leather, but they are rarely employed in
mechanical constructions.
=Vulcanised fibre= is often used for similar purposes to leather, as for
valves, seatings, joints, &c. It is made in two varieties, medium and
hard, and in sheets up to 1″ thick.
=Ebonite.= A hard, black, horny substance, moulded into any required
shape.
=Papier mâché.= Solid paper, moulded from pulp into any required form.
=Asbestos,= in sheets, cord, packing of various sections, loose fibre,
millboard, &c.
=Ivory,= from tusks and teeth.
=Bone.=
=Vegetable ivory;= nuts about the size of eggs.
Packings for glands, &c., are made of cotton, hemp, and other fibres,
asbestos, indiarubber, &c., in round, square, and other sections.
Section 100.--HEATING APPARATUS.
For general purposes this comprises Furnaces, Stoves, Ranges, Ovens,
Boilers (see Section 6), Hot-blast, Steam-heated Vessels, Gas Jets,
&c., most of which are tolerably well known and in common use.
For special purposes in connection with machinery various heating
devices are required, of which steam and gas are those most
universally used. Steam tubes or coils may be carried through any
fixed or movable part of a machine. Steam-heated surfaces, such as
tables, pans, chambers, &c., steam-jacketed cylinders, and similar
contrivances, are much used. Gas jets from perforated tubes, which may
be shaped to any required position, are also convenient for dry heat
and higher temperatures than can be obtained from steam.
Hot irons are sometimes used, shaped to fit a cavity, but of course
require to be replaced periodically.
Hot water in pipes or jackets, and hot air in flues are common
appliances for warming and drying; with the former its circulation
must be provided for, and with the latter, either a forced draught or
an upward inclination given to the flues to maintain circulation.
=1876. Gill pipes= for radiating the beat of steam or hot water.
=1877. Gill stove,= on similar principle, presents an extensive surface
in contact with the air for radiation of heat.
Section 101.--DRAWING AND ROLLING METALS, &c.
=1878. Rolls for bar iron,= grooved to suit the section required,
one-half the groove being usually in each roll, and the size and shape
of the grooves are graduated down from that of the square billet to the
finished bar.
=1879. Grooved rolls= for producing a tapered bar.
=1880. Rollers for turning up= and welding tubes from a flat strip.
=1881. Bending rollers.=
=1882. Rolls for solid tyres,= without a weld.
=1883. Wire drawing apparatus.=
For grips for drawing wire, &c., see Nos. 505, 518. Laths of various
sections are drawn through suitable steel dies by a draw bench; the
end of the lath is held by a grip tongs and the lath drawn forcibly
through the dies (using a lubricant) and afterwards straightened.
Rolling does not answer for this kind of work.
The drawing frame used for cotton and other fibres has two, three, or
more pairs of rollers; the lower rollers are grooved longitudinally
and the upper ones weighted and covered with leather, the lower ones
being geared together to drive at proportionate speeds, so that in
passing through, the material is stretched between each pair of
rollers, the object being to extend and lay all the fibres parallel.
For drawing lead pipes, see No. 1183. Earthenware pipes are made by a
similar process.
Section 102.--STRUTS AND TIES.
=1884. Ordinary solid swelled distance rod= with collars, used for
compressive strains.
=1885. Similar strut,= but formed of tube with end collars screwed in.
=1886. Double flat-bar cambered strut,= stiffened by distance pieces and
bolts.
=1887, 1888, 1889, & 1890. Sections of varieties of the foregoing.=
=1891. Braced strut;= usually of flat bars on edge, riveted together at
the intersections.
=1892. Tubular swelled strut,= of plate iron, used for masts, sheer
legs, crane jibs, &c.
=1893. Built up strut,= from segmental bars.
=1894. Trussed strut;= the trussing is 90° apart, but may be at any
angle; the central bar of course takes the actual thrust, and the truss
rods keep it from bending or buckling. See also Nos. 295 to 300, 320.
=Ties,= for tensile strain only are usually of round iron, flat or
other simple section, tube, or even chain, rope, or wire.
[Illustration: 1876.-1894.]
Section 103.--MARINE ENGINES (TYPES OF).
Many varieties will be found illustrated under Section 32. The following
are modern types:--