the use of a pen, the tracer _t_, fig. 10, would be terminated above as
a hollow conical cup, into which he would introduce a pointed style held
as a pen. In this case the tracer _t_, would be made as short or _low_
as possible, to bring the style so much the nearer to the paper; and
thus to prevent all anomalous movements.
OF
AN EYE MACHINE,
_Or Machine for making the Eyes of Hooks and Eyes_.
If it were enquired why this Machine is offered to the public without
the Hook Machine; the answer would be, this only is _finished_: and it
is wished to present nothing here that admits even a doubt of its
utility. The drawings given in Plate 20, figs. 1, 2 and 3, are more
intended to be useful in the construction of this Machine than complete
in _appearance_: so that nothing has been done by way of shading, but
what it was thought would the better distinguish the parts from each
other, and facilitate their assemblage in one effective Machine. The
Machine consists first of a slide _A B_, (worked by a lever-handle, a
crank, or any proper first motion.) It glides between two cheeks _C D_,
(see the _end_ view in fig. 1) connected with the several parts about to
be mentioned. This slide is marked _A B_ in all the three figures. It
carries (by means of the screws _a b_, coming through the slits _c d_,
in the main Plate _E F_) a plate _g_, the chief use of which is to
support a tumbler _e_, whose use is to throw the eye, when made, from
the machinery: which tumbler is kept to its work by the spring _i_, as
will be further explained presently. This slide itself has a peculiar
form at the end _B_, (fig. 2) which is shewn by dotted lines at _c d_ in
fig. 1. It is a slit, with the corners rounded off for the purpose of
working the springs _now_ to be described. These springs _m n_, (see
fig. 2) are fixed to a _cock_, itself screwed behind the main plate: and
they come through the latter to the _left-hand-ends_ of the small curved
mortices seen (with the springs) at _m n_ fig. 1. The slide _A B_ then,
with its forked end shewn by the dotted lines at _c d_, is destined to
take the springs _m n_ and carry them to _r s_, where they are _now_
seen surrounded by the eye _almost_ formed: for in this motion these
springs take the wire (shewn by the lines dotted _across_ the Machine
and previously _cut_ by the sheers _u_) and meeting with the obstacles
_t v_, being the thicker parts of the clams _t v w_, they bend it into
the form _r s_--when the screws _a b_ lay hold of the sloping ends of
the clams _c t w v d_, and squeeze them together; by which operation the
hooks _t v_ finish the _eye_, by rolling its two ends round the springs
_m n_ now in the position _r s_. Where note, that the slit _c d_ of the
slide _A B_ is so formed as, when it has carried these springs _m n_ to
_r s_, to slide forward without doing any thing more to them, while
closing the clams. It performs, however, some other less important
operations, to which it is now necessary to allude: among other things
this slide works the sheers _u_ that cut the wire, and _that_, by means
of the doubly wedged hook _x_, which goes back with the plate _G_, doing
nothing: but which by the action of its springs fixed at _a_, falls
_under_ the sloping end of the sheers _u_; and, when the slide, by the
screw _b_, carries it to the right hand, raises the end _x_ of the
sheers _u_, and cuts the wire near _v_, to prepare it for the operations
already described. The part _y_ in the two figs. 1 and 2, is the other
cheek of the sheers fixed by screws to the main plate, and covered by a
small plate _z_, in which a _nick_ is cut to form a passage for the
wire, and present it to the sheers, that they may cut it to the proper
length, after having directed it right across the springs _r s_, then
placed by their elasticity at _m n_. It hardly need be added that a
_stop_ is placed at _o_, to determine the length of the wire so as to
form the eye complete, and not to admit more wire than is sufficient;
all which is regulated between the sheers and the _stop_, by proper
adjusting screws, which it is very easy to suppose or supply.
Fig. 3 is intended chiefly to shew the mechanism by which the eye, when
finished, is thrown off the pin round which it is bent by the springs _m
n_. It consists of a _tumbler_ _e_, placed in a mortice in the end of
the plate _g_, and kept to a given position by the pressure of the
spring _i_. When the slide _A B_ is carried forward, toward _E_, to
perform the operations already noticed, this tumbler _e_, gives way to
the angle _G_ of the _doffing lever_ _m G_, (this lever being shewn also
between _c m_ & _d n_ in fig. 1) and rides towards _m_ without producing
any effect either on the plate _G_ or the lever _m G_: but when it has
once passed the said angle _G_, it cannot go again toward _F_ without
depressing smartly the end _G_ of that lever, and thereby raising the
end _m_, thus starting the eye from the stud _m_, round which it had
been bent by the processes above described.
At the right of fig. 1 near _F_, is an object, the use of which is too
evident to need description. It is a double spring for the purpose of
keeping the _hooks_ _c t w v d_ pressed against the pins, near _t v_,
which determine the position of the said hooks; and the degree of _bend_
first given to the wire by passing the points _t v_.
There are some less important parts and operations left undrawn, in
order to prevent confusion in the figures: but they are such as would
strike any person having the above under his eye. In a word I have done
what I thought best to aid the construction of this Instrument:--which
is represented at two thirds of its natural size--but whose dimensions,
of course, would vary with that of the objects to be produced by it.
OF
A VENTILATOR,
_Rotatory yet by pressure_.
By this title I wish to distinguish this Ventilator from all such as act
by the mere centrifugal force of the air: and to make this distinction
the more palpable, I would add that _this_ Machine acts like a pump,
that is by means of a space alternately contracted and expanded, into
which the air enters, and from which it is expelled _by force_ as water
is from a pump. The means are the following: _A B_ (fig. 4 of Plate 20)
is a hollow cylinder, of a diameter proportioned to the effect wanted to
be produced. _C_ is a cylinder closed at both ends, which fills that
just mentioned as far as the length goes, excepting _a play_ of about
1/8 of an inch. This interior cylinder revolves in the former; but _not_
on its own centre. It revolves on an axis _E_ eccentric to itself, but
exactly concentric with the outer cylinder _A B_. The centre therefore,
of the inner cylinder _C_, describes a circle within the outer one,
which is always parallel to its circumference. On the axis _of motion_
of this cylinder _C_, and outside of that _A B_, are fixed two cranks _E
F_ fig. 5, which exactly reach from its centre of motion to its centre
of figure: so that whatever circle the latter describes _in_ the large
cylinder, the former describe the same line _without it_. And hence any
slide or valve _D_, driven by these cranks, will always touch, or be
equally near, the circumference of that interior cylinder _C_. The valve
_D_ then, worked by the bars _G_ from without, forms a constant
separation between the right and left hand parts of the _lunular_ space
left between the fixed and moveable cylinders; and if the latter turns
from _C_ by _B_ to _D_, the right hand space _C B G_ is the _plenum_,
and the left hand space _C A D_ is the vacuum of this Instrument; or in
other words the air will flow _in_, through the passage _H_, and flow
_out_ through the passage _I_: and by a contrary motion of _C_, it would
do the contrary--but I prefer the first process because any pressure
within the valve _D_ is not liable, then, to press the valve upon the
drum _C_, and produce contact and friction; which in the second case it
might do. Suffice it to add, that the quantity of air displaced at each
revolution of _C_ round its centre of motion, is the difference between
the area of the drum _C_ and that of the cylinder _A B_: and that its
quantity at each part of the revolution is proportionate to the
curvilinear triangle _G B_, multiplied by the length of either cylinder.
In the prospectus, this Machine was said to be good as “a gas meter,”
which I still think it is. For such a purpose however, _friction and
eccentricity of weight_ should be obviated, by placing the axis _E_, _in
a perpendicular position_: when I doubt not it would measure flowing gas
better than many of the machines that have been proposed for that
purpose.
OF
A COMBINATION OF WHEELS
_To raise Water_.
This _mode_ of raising water in its simplicity, is I think called the
Persian wheel. The buckets hang upon centres, dip in the _under_ water,
fill themselves there, and by meeting an obstacle above which turns the
buckets aside, they empty themselves into the upper _back_, from which
the water is conveyed to the general reservoir prepared for it. This
present Machine is such an extension of the above principle as to make
it applicable to considerable degrees of elevation, and to many
situations where a single wheel would be of no service. Having observed
that in every _train of wheels_, the circumferences of any two wheels,
have motions _towards_ each other, as well as _from_ each other; I
perceived that, in a vertical train, this circumstance might be laid
hold of to compose a machine for raising water. Be therefore, (Plate 21,
fig. 1) _A B C D_ four of a set of wheels thus intended: on the left of
the lowest wheel the buckets move _upward_, as indicated by the arrow;
while those at _B_ move downward, coming thus to meet the former. The
buckets _A_ are full, and those _B_ are empty; and as the latter, by the
motions of the _equal_ toothed wheels on which they are hung will
infallibly meet the former, and even plunge into them at _I K_ and _L_,
it is only to put a _clack_ of leather or a valve, in the bottom of
_all_ the buckets, and we have a machine that will raise water to the
top-most wheel, be it ever so high, and there the water will be poured
out into the vessel _M_, as in the common Persian wheel above alluded
to. On this principle the first change of buckets will take place at
_I_; where the lower bucket belonging to the wheel _B G_ will take the
water from the upper bucket of the wheel _A H_; when the bucket _I_ will
go down, nearly empty, by _H_ and fill itself again in the under water;
But the bucket of the wheel _B G_ having now _got_ the water, will rise
by _G_ to _K_, where another bucket belonging to the wheel _C F_ will
come empty, and plunging itself into _that_, take its water and go
upward by way of _C_ to _L_, where a similar change will take place and
the water from _L_ will rise by _E_ to _M_, into which vessel it will be
poured by the _canting_ of the bucket as seen in the figure. Thus it
appears that any number of toothed wheels geering together, surrounded
with buckets _valved_ at bottom, and receiving power from any one of
their number, will raise simply and effectually a quantity of water _not
small_ in proportion to the power employed, and by means that promise
great durability to the Machine.
OF
AN ECCENTRIC BAR PRESS,
_For clearing wetted goods of Water_.
This press (see Plate 21, fig. 2) is indefinitely powerful. It was
invented for the use of my late beloved brother, then contractor with
government for cleansing the sea bedding. It is composed of a centre
piece _A_, strongly fixed to a post in the ground, the bars _A B_ _A C_
being suspended above it, so as to remain horizontally moveable, while
describing 1/4 of a revolution round the general centre _A_. The
blankets (or other goods) are put into the space _s_, (on a net nailed
_under_ the bars) while in the position _A B_; and the whole is then
thrown with force towards _B C_; the length _A C_ being so calculated as
to cease pressing at the desired moment: for such is the _power_ of this
Machine, even without this projectile force, that were the stress not
moderated, nothing could remain whole under its operation. It is clear
however, that, when this operation _begins_ at _s_, the relative motion
of the jaws _s_ and _B_ is assignable, and even visible, as shewn by the
dotted circles; but as the whole approaches toward _B C_ that relative
motion becomes insensible, the circles parallel, and consequently the
power infinite: which is all I shall say on the theory of this Machine.
OF
A COLOUR MILL,
_For Calico Printers_.
This Machine is delineated in fig. 3 of Plate 21. It has several
properties which I think important in the process of grinding colours,
either in a wet state or a dry. It consists of a frame _A B_, which has
a hollow centre, through which the axis of the bevel wheel _C D_ is
brought in such manner as to geer with the bevel pinion _P_, in whatever
position the frame _A B_ may be placed. The axis of the pinion _P_
carries a vessel _of which_ _E F G_ _is a section_, and in which rolls a
well turned and heavy ball _H_, _upon_ the colour to be ground: which it
crushes in the line of direction of its centre, and to a greater or
lesser _width_ according to the diameter of the ball, as compared with
the section of the groove _E G_, in which it rolls. Now as the motion of
the vessel _E G F_, is oblique to the perpendicular, the contact between
it and the ball does _not_ take place in any great circle of the latter:
but is constantly varying by a twist in its motion dependent upon the
angle of the vessel’s inclination to the horizon. From hence arises the
_impossibility_ of any colour remaining on the ball unground: and in
order likewise, that none may remain uncrushed in any part of the vessel
_E F G_, the frame _A B_ gives it constantly new positions, _one_ of
which is represented by the dotted lines _I K_: where it is seen that
the ball bears on a different line of the vessel’s bottom than it did
before. This also adds still greater change of action to the ball
itself, and occasions (taking both these properties together) an
unbounded variety of effect, which necessarily brings every particle of
colour under the ball by the mere continuance of motion: and thus grinds
it all without any care on the part of the attendants. It may be added,
that this vibrating motion of the frame _A B_, is easily made to result
from an eccentric stud and proper connecting rods behind the frame; all
which is too easy to require further description.
OF
A DYNAMOMETER,
_Or a second Machine to measure power & resistance in motion_.
In Plate 21 fig. 4, there is a representation of this Instrument. It is
composed of a frame _A B_, containing a strong shaft _C D_, on which are
placed the three following objects. First, a fixed pulley _E_, working
by a strap, the Machine whose resistance is to be measured. 2ndly, a
loose pulley _F_, receiving the power from the _mover_ whatever it be.
And 3rdly, a barrel _G_, which is the acting pulley, when the strap is
put on it from _F_ in the common method. But this barrel _G_ acts by
means of a barrel-spring within it, which is hooked by one end to the
boss of the shaft, and the other to the rim of the barrel, as is usual
for barrel-springs in general. Now the power produces the desired motion
by coiling this spring to the necessary degree: and to make that degree
_visible_, there is fixed to this barrel _G_ a spiral _s_, which as the
spring bends, drives _outward_ the stud _t_, and with it the _finger_
_v_, which, pointing to the graduated scale, shews at once the number of
pounds with which the spring acts on the shaft _C D_ to turn it. By
these means the stress on the straps and on the Machine turned is known;
of which also the velocity is easily determined by counting the number
of revolutions performed by either of the pulleys _E F G_, which are
alike in diameter.
* * * * *
In ending the first part of this work, I gave my readers room to expect
_this part_ “within three months,” and am happy now to fulfil that
engagement. Although these pages contain fewer errors than the
former--an apology is due for those that have crept in: to which I add
the promise that every thing shall be done to lessen them further in the
future parts, and wholly to correct them before the work closes.
Page 100, line 2, for “:”, read ∷;
„ 126, „ 4, „ “on its surface” read at its pitch line.
„ 126, „ 17, „ “its height _f g_,” read the length required.
„ 129, „ 16, „ “2,” read 4,
„ „ „ 20, „ “imperfect,” read homely.
„ 144, „ 7, take away “_alone_.”
„ „ „ 8, for “usually” read chiefly.
„ 146, „ 23, for “the friction,” read it.
„ 147, „ 1, for “nothing,” read little or nothing.
In fig. 7 of Plate 19, slope the groove of both _faces_ the same way.
* * * * *
A few words seem wanting to complete the description of the Cutting
Engine above given. They relate principally to the cutter-frame and
cutters. Although, with a view to celerity, I have shewn the cutter
_out_ of the frame (fig. 4) yet a common frame, carrying the arbor on
points, may be used with propriety; and would often be an eligible
substitute for the frame above described. In cutting bevel wheels
however, either on this Machine or that to be described, there is a form
of the cutter frame which leaves less freedom of choice, as the cutter
itself _must_ have a peculiar form and position. To return to the cutter
for spur wheels, their form (or section) depends on the degree of
_finish_ which the wheels require. For _rough_ work they may be
cylindrical on the face, the sides being _under cut_, so as to leave
them thickest at the circumference--whence a certain coarseness of cut
ensues, but without _any injury_ to the spiral form. But, generally
speaking, the cutters are best, when made a little tapering towards the
edge, and toothed on both sides as well as on the circumference. The
teeth should be tolerably fine, but not very so, unless great
_smoothness_ of surface were required: and we have seen above that, in
this System, great smoothness is very seldom necessary, _provided the
obliquities be correct_. I may add, that those cutters used on common
engines, whose great rapidity compensates for the small number of their
teeth, would not answer here, on account of the twisting motion in the
wheel. But nothing prevents using cutters, so formed on the sides, as to
round off the teeth in the act of cutting--only the cutter must be so
thin as that its thickness, added to the aforesaid twist, may not make
the _spaces_ too wide. A little observation will render these things
familiar to an attentive observer: nor shall this work conclude before
all that I have gathered from long observation on this subject, be fully
known to my readers.
J. W.
_5, Bedford-street, Chorlton Row,_
_20th. November, 1822._
PART THIRD.
A NEW CENTURY OF
Inventions.
It has been observed and regretted by a well-known writer, that “a
periodical work resembles a public carriage--which _must_ depart at the
usual hour, whether full or empty;”--and having undertaken to deliver
_this_ work at stated periods, I have found myself in a situation not
unsimilar: the consequence of which has been a too cursory view of some
of the subjects. I feel however, that _this_ is not a sufficient apology
for any essential defect: nor would it be more so to say that, although
verging to old age, I am still a young author. Yet I may claim the
privilege of supplying, in the latter parts of the work, what is most
deficient in the former; and thus of proving that I do not intentionally
neglect any thing that might make it practically useful.
With these views I commence this third _part_: intending first to
continue the description of the Cutting Engine given at page 121, _and
here applied to Bevil Wheels_; and then to re-consider, shortly, one or
two other objects, that were too rapidly passed over in their proper
places.
Plate 22, repeats at fig. 1, the first figure of Plate 15; by way of
shewing the additions required to extend this method of cutting teeth,
to Bevil Wheels. These additions are _first_, a disk _n n_,
concentrically fixed to the main axis _A B_ of the engine. And,
_second_, an inclined plane _o_, of _variable_ obliquity, connected by
a joint with the _forked_ sliding bar _p q_, by which the plane _o_ is
put in contact with the disk, at whatever distance the cutter-stand _e
f_ may be from the common centre, _which distance_ depends, of course,
on the diameter of the wheel to be cut; and to secure which is the
office of the fixing screw _r_, in the figure.
It is now evident that for the disk _n n_, and the shaft _A B_ to rise,
the slide _p q_ and the cutter-stand _e f_ must recede: and _this_ more
or less according to the degree of obliquity of the inclined plane _o_,
that is according to the slope of the _bottom_ of the teeth in the wheel
_w_: see the dotted line _w p_.
A circumstance presents itself, that should be here explained: when the
bevil of the wheel _w_, or the cone of which the wheel is a part, is
very obtuse, the cutter-stand _e f_, can not be driven back by the
action of the disk _n n_ on the plane _o_, without too great a stress
being applied from below, to the axis _A B_. (See the apparatus _I M O
N_, Plate 16, fig. 2.) In this case therefore, the handle _R_ is not
used: but a weight is suspended to the end _N_ of the lever _M N_,
sufficient to give the whole System _A B_, a tendency _to rise_; and the
operator now acts on the screw _g_, so as to draw back the plane _o_; by
which motion the disk _m n_ with it’s axis _A B_ is _suffered_ to move
upward, and the wheel is cut, as desired. But on the other hand when the
wheels are portions of _acute_ cones, they are cut by means of the
aforesaid handle; by which the plane _o_ and the cutter-stand are
_forced_ backward as before intimated.
We proceed now to describe the perpendicular part of the cutter stand _e
f_; which is made double, as shewn at _i k_ in fig. 4 of Plate 15; and
is also perforated at various heights to receive the bolt which forms
the centre of motion of the arm _m u_, the latter having a cylindrical
boss _u_, fitted into the _fork_ of the stand _e f_, and so graduated as
to determine the angle of it’s obliquity to the horizon, or it’s
parallelism to the dotted line _w p_, which indicates the slope of the
bottom of the teeth on the wheel. Finally, the cutter-frame _x_ is
fastened to this arm at right angles to it, and thus forms a right angle
(or nearly so) with the surface of the wheel: and is, moreover, directed
to the centre, produced, of the shaft _A B_. This latter fact is
strictly true, only when the teeth required are of so common a kind as
_not_ to require greater exactness: for in theory the sides of the
cutter (supposed cylindrical) must alternately direct to that
centre--namely, _that_ side which is actually cutting: so that a
provision must be made to shift the cutter spindle sideways, a distance
equal to it’s diameter; this being no more than what is necessary in
every system of wheel cutting.
We may also consider here, the form of the cutter itself, _v_, fig. 1.
It is slightly conical, (more or less so according to it’s use) and of
no greater diameter than the smallest width of the _spaces_ between the
teeth of the wheel. A common disk-like cutter would not produce perfect,
nor even tolerable teeth on a bevil wheel. The reason of this will
appear by considering that a spiral line, either on a cone or it’s base,
_turns_ more the further it is from the centre, and less the nearer it
comes to it. So that a _flat_ cutter placed at _any_ angle, is parallel
to the curve at _one_ place only; whence the propriety of using a cutter
of the kind represented in this figure. It is however true, that the
first opening of the spaces may be made with a common cutter; but it
should be very thin comparatively with the spaces required: and it’s cut
would serve only as a _sketch_ of such space, serving principally to
permit the metal to escape while finishing the teeth with the cutter
just described.