Some of the most primitive methods are still in use, and may possibly
still be found of service in particular cases.
=1019. Scoop wheel.=
=1020. Dipping trough.=
=1021. Endless chain of buckets.=
=1022. Archimedean screw;= a spiral pipe serves the same purpose as the
worm revolving in a cylindrical case.
[Illustration: 1006.-1022.]
=1023. Chain pump,= frequently used still. The lower length of pipe
should be bored to fit the buckets on chain; the rest of the pipe may be
a little larger in diameter and not bored.
=1024. Lifting wheel= for raising water.
The following four examples are machines for raising water to any height
by employing a fall of water of comparative low pressure:--
=1025. Hydraulic ram.= A stream of water runs down the incline pipe and
flows away at the ball valve; when its speed reaches a certain point it
suddenly closes the ball valve, and the shock opens the delivery valve,
water flows into the air vessel till the power of the stream is checked,
when the delivery valve closes, the ball drops, and the action is
repeated.
=1026. The Robinet.= Direct-action water pressure self-acting pump;
performs the same work as the hydraulic ram, that is by using a low fall
and large quantity of water it raises a smaller quantity to a greater
height, the low-pressure water acting on the large double-acting piston.
The valve is reversed by the motion of the engine.
=1027. Hydraulic pumping engine.= A modification of the Robinet. ~A~ is
the driving cylinder, ~B~ the pump. The main slide valve is worked by
two pistons, and the pressure water distributed by an auxiliary four-way
cock or small slide valve, connected to a stop rod from the main
crosshead. See also No. 1741. See Sec. 93.
=1028. Water wheel and pump.=
=1029. Single-acting bucket or suction pump.=
=1030. Single-acting ram force pump.= Sometimes an open top cylinder and
piston are used instead of a ram, as No. 1029.
=1031. Double-acting ram and piston pump.= Forces on both strokes; sucks
only on the up stroke.
=1032. Double-acting plunger or ram pump,= externally packed; a
favourite arrangement.
=1033. Double-acting piston pump,= four valves. This is of course a type
of a very great variety of pumps.
=1034. Double-action piston pump,= without valves. The piston has an
oscillating or radial motion (see plan), as well as an up and down
motion, so that the two ports are alternately open to the upper and
under side of piston by the small passages ~A~ ~A~. The required motion
can be obtained from No. 406, crank motion.
=1035. Rope pump.= A simple endless soft or porous rope absorbs water at
its lower part (immersed), which water is pressed out of it between the
rollers at top.
=1036. Apparatus to supply air to air vessels.= The main pump at every
stroke draws a small quantity of water from the small air vessel ~A~,
and on the return stroke forces an equal quantity of air from the
smaller to the larger vessel ~B~. ~C~ is a double air valve.
=1037. Combined bucket and plunger pump= draws on the up stroke only,
but delivers on both strokes.
=1038. Air pump,= with foot and head valves.
=1039. Hand or power pump.= Can be thrown into action from the crank
shaft by fastening the set screw, or may be worked independently by the
hand lever.
=1040. “Worthington” pattern of plunger pump,= double acting.
[Illustration: 1023.-1040.]
=1041. Double barrel pump,= with bucket pistons. The water passes both
pistons, which are fitted with valves opening opposite ways.
=1042. Oscillating sector= or quadrant pump, with one vane or piston.
=1043. Double quadrant pump.= The two vanes are worked by links from a
single crank.
=1044. Oscillating pump,= with two radial vanes keyed to a central
rocking shaft.
=1045. Hollow plug;= oil or water feeder.
=1046. Double ram pump.=
Rising mains in mines and wells have been used as the main pump rods
in some instances.
In pumping up to a tank or reservoir from which a down service pipe is
taken, the pump can be arranged to deliver into this pipe at its
nearest convenient point, instead of having a second pipe from the
pump to the tank.
=1047. Schmid’s trunk cyl. hydraulic pumping engine= utilises a
low-pressure supply to force from the annular side of the piston a
high-pressure service.
See also rotary engines and pumps, Section 75.
Pumping engines, Section 61.