Improvements in or relating to Power-transmission Apparatus.
Year: 1897

page_text: Date of Application, 18th June, 1897
Complete Specification Left, 18th Apr., 1898-Accepted, 18th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Power-transmission Apparatus.
I, JOHN WILLIAM HALL, of 1, Wiltshire Road, Brixton, in the County of
Surrey, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to power-transmission apparatus of the kind described
in the Specifications of prior Letters Patent Nos. 6590/96 and 7479/96 granted
to me, its object being the construction of improved details of such apparatus.
One of the objects of the present invention is the provision of mechanism for
correlating the adjustment of a crank pin to which the connecting-rods of the
motor cylinders are connected to the adjustment of a valve by which the flow of
fluid through a "short-circuiting" passage is controlled, or for correlating the
adjustment of the equivalents of such valve and crank pin; other objects of this
invention include improved constructions of mechanism for operating and con-
trolling the short-circuiting valve, of gear controlling the slide valves of the
motor cylinders, mechanism for adjusting the pump crank pins, expansion
chambers for the fluid contents of the apparatus, improved charging-valves and
an improvement relating to the utilization of the fluid circulated from one part
of the apparatus to another.
One example of such construction is as follows:--One one side of a disc which
rotates in company with the adjustable crank-pin of the motor cylinders is a
spiral tooth, and on the same disc is a spiral cam; this tooth and cam together
control the short-circuiting valve automatically by means of a lever which at
one end is connected to a rocker pivotted to a fixed support; the rocker is pro-
vided with teeth which gear with the spiral tooth and therefore will be oscillated
by rotation of the disc aforesaid. The lever connected to the rocker is arranged
to bear upon the spiral cam and to operate directly or through mechanism upon
the short-circuiting valve.
The movement of the lever is normally automatically effected by the action
of the cam upon it, and the object of the spiral tooth and rocker is to so move
the lever as to keep one part of it on the parts of the spiral cam or of the
surface on which that cam is formed, with which it is desired that it should
co-operate in the different angular positions of the crank pin and the disc
moving with the latter. Conveniently the lever engages a shaft arranged to
slide endwise in the crank-shaft of the motor cylinders, and connected with the
short-circuiting valve. The spiral cam may be one which extends spirally through
360°, its face sloping gradually down from its highest point in opposite directions
through 180° each way; the spiral tooth, cam and rocker are so disposed in
relation to each other that the movements of the short-circuiting valve are cor-
related in the desired manner to the adjustment of the crank-pin of the motor
cylinders.
If desired, instead of operating the valve by a shaft which is movable endwise

page_text: under the action of the lever, that lever or apparatus such as toothed gear sub-
stituted therefor may be arranged to adjust that shaft by rotating it instead
of reciprocating it.
In one construction of apparatus according to this invention it is necessary
to the obtainment of the desired variations in the speed of the driven part that
when the crank-pin of the motor cylinders is moved from what may be termed
a neutral position, the short-circuiting valve should be slowly closed through
the first 180° of such movement of the crank-pin, and should not thereafter
commence to open but should be kept closed through a continuation of such
movement, say through a further 180° in the same direction; this result is
ensured by making the spiral cam merge into the flat surface upon which it is
formed on the end of each arc 180° on each side of its highest portion, and
by causing the lever to travel upon the flat instead of upon the cam at such
times as the valve is to be kept closed.
Another improvement forming part of the present invention comprises means
which normally keep the lever above referred to in gear with the cam by which
it is operated, but permit it to be operated manually when desired and return
it to its proper position on the cam when released; for instance one end of the
lever can be controlled by a spring in such a manner that it will tend always
to bear upon the cam, there being a slot made in the lever to receive the end
of a link operated manually, the slot being so arranged that the automatic
adjustment of the lever by the cam will not be interfered with by the link
employed to move the lever by hand. The spring may be contained between
the piston and cover of a cylinder pivotted to the frame, the piston rod being
connected to the lever.
If desired the link aforesaid may be in operative connection with the brake
gear so that operation of the lever independently of the cam causes a simultaneous
application of the brake.
The restoration of the lever to its proper place with regard to the cam will
occur under the action of the spring and rocker before referred to, even though
the cam should have been adjusted in the interval between the removal of the
lever from contact therewith and its return to place.
In order to prevent the occurrence of violent shocks or stresses in the working
parts of the apparatus which might arise upon the possibly sudden restoration
of the lever before referred to, to its working position on the cam, the lever should
be so controlled that it will be impossible for it to go back to its proper or
working position except when the adjustable crank pin and disc or cam attached
thereto, are in their neutral or non-working position.
This may be effected as follows:-On the edge of the lever next the cam is
a projection on which is pivotted a short lever, one end of which is fitted with
a spring and the other end of which goes under or behind the edge of a further
portion of the spiral cam face which extends beyond the edge of that part of
the cam face on which the main lever works.
The short lever is so pivotted and the further extended edge of the cam is
so formed as to permit of the normal movement of the lever due to the movements
of the disc and cam face, and also to permit of the complete withdrawal of the
lever and its roller from the cam by means of the aforesaid link, when so desired,
to stop the apparatus, but it will be impossible for the lever to return to its
working position until the disc and cam have been so rotated that a notch cut
in the extended edge of the cam (and which corresponds in position with the.
neutral or non-working position of the adjustable crank pin) coincides with
the end of the short secondary lever pivotted on the main lever thus allowing the
latter to return to its working position on the cam which previously it could
not do owing to the end of the short lever resting on the face of the cam instead
of behind it. Any equivalent interlocking device may be employed for a like
purpose:
A convenient connection between the short-circuiting valve and shaft by which

page_text: it is operated from the exterior of the apparatus comprises a disc adapted to
slide upon a portion of the motor crank-shaft; this disc is encircled by a strap,
which is coupled by a universal joint to one end of a link, the other end of
which is operatively connected with the short-circuiting valve. The link is so
disposed that movement of the disc from the exterior of the apparatus in the
direction of the axial line of the adjusting shaft will effect to the desired degree
the adjustment of the valve, but so that movement of the disc in its own plane
will have no material effect upon the valve.
An alternative construction of control gear for the short-circuiting valve is
one in which it may very conveniently be combined with adjusting gear for
an eccentric sheave controlling the slide valves regulating the passage of fluid
to the motor cylinders, although these gears may be used separately if desired:
The control gear for the short-circuiting valve comprises a sleeve rotatable on
a stationary stud; this sleeve is externally screw-threaded and geared with a
pinion keyed on the end of an operating shaft. A nut encircles the screw.
threaded portion of the sleeve and has a circular groove turned therein to receive
one end of a lever or other device, which by the endwise movement of the nut
will be caused to operate the valve. From the nut extend two fingers adapted
to slide in holes' in a casing encircling the sleeve. Although this casing is
given under certain circumstances a slight angular adjustment relatively to
the stationary stud, this angular movement may be disregarded and the casing
may be considered as stationary. To adjust the valve by the gear just described
the pinion is rotated to turn the sleeve; upon such rotation of the sleeve the nut
which is prevented from rotating with the sleeve will be caused to travel endwise
along the screw-threaded portion thereof so as to carry with it the valve-adjusting
device, and thus adjust the valve. The adjustment of the eccentric sheave is
effected by means of a pinion fixed on the end of an extension from the crank
pin of the motor cylinders so as to be concentric with the axis of the crank shaft ;
this pinion engages with an internally toothed ring fixed to the sheave. The
diameter of the pinion at its pitch line is half the pitch-line diameter of the
internally toothed ring, so that any point on the pitch line of the pinion will
describe a straight line relatively to the ring when the pinion and ring are
rotated in gear with each other, and as it describes a straight line relatively
to the ring it will also describe a straight line relatively to the sheave which is
integral with the ring. The pinion is so disposed that the axis of the crank
pin passes through a point in the pitch line thereof and the ring is concentric
with the axis of rotation of the apparatus, so that adjustment of the crank pin
by adjustment of the crank shaft will cause the eccentric to turn about the fixed
stud so as to maintain a constant angle with the virtual radius of the crank,
that is to say, so that the angular advance of the eccentric is constant.
By an alternative construction of valve gear according to this invention the
sheave is pivotted eccentrically upon a bearing which is co-axial with the axis
of rotation of the driven shaft, and upon that sheave is fixed a guide or guides
with which one or more projections from the crank pin engage; the crank
pin thus engaged with the guides so acts upon them as to turn the latter and the
sheave about the bearing aforesaid in such a manner as to preserve the appro-
priate angular advance of the eccentric, despite the movement of the crank pin
and eccentric relatively to the shaft in their adjustment.
In one construction of this device the guides intersect each other and the
axis of the bearing and have upon the centre line of one of them the centre of
the sheave; in this case they are engaged by projections from the crank pin
situated at the opposite ends of the diameter of a circle in which the crank pin
moves during its adjustment.
The employment of two projections from the crank pin and guides upon the
eccentric is necessary where one of the projections in its movement of adjustment
becomes concentric with the axis of rotation of the crank shaft and with the
point of intersection of the guides, so as to be unable to exert a turning moment

page_text: upon the guides; but if the range of adjustment is limited so that the projection
does not thus become concentric with the parts referred to, a single projection
and guide will suffice.
Instead of the projection and guides, any other linkage such as one giving
say a straight-line motion, may be adopted between the crank pin and the
eccentric sheave to give the desired movement to the latter during the variation
of throw of the former as described.
In apparatus of the kind described the throw of the crank pins of the pump
portion of the device may be made variable by means of "floating" gear of the
kind described in the said Specification of prior Letters Patent No. 6590 of 1896.
To compensate for variation in the bulk of the liquid contained in the apparatus
expansion-chambers are provided; one of these conveniently takes the form of a
cylindrical cavity in say the fixed shaft or pivot of the apparatus, communicating
by way of the inner end with the interior of the casing and capable of. being
connected by a branch passage with a reservoir or pump. Within the cavity fits
a hydraulically-packed piston, loaded for example by means of a spring in com-
pression between it and the closed end of the cavity. Any variation of the bulk
of liquid contained in the casing will be automatically compensated by the move-
ment of the loaded piston so that no air-spaces will occur upon contraction of
the liquid, nor will any undue stress be put on the apparatus by its expansion;
moreover the packing of the piston or the devices therein can be arranged to
constitute a non-return valve past which oil can be forced into the apparatus for
charging.
If desired the cavity may be maintained in communication with an accumu-
lator.
In the apparatus described in the aforesaid specifications of prior patents
circulation of liquid occurs in a circuit which is almost wholly internal; but the
circulation might be made to take place through an external circuit in order that
the liquid under pressure therein should be utilised if desired for useful pur-
poses. There may be a cooler in the circuit, whether internal or external, if
desired.
Dated this 18th day of June 1897.
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Power-transmission Apparatus.
I, WILLIAM HALL, of 15, Holland Road, formerly of 1, Wiltshire Road,
Brixton, in the County of Surrey, Engineer, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement:-
This invention relates to power-transmission apparatus of the kind described
in the Specifications of prior Letters Patent No. 6590/96 and No. 7479/96 granted
to me, its object being the construction of improved details for such apparatus.
One of the objects of the present invention is the provision, in such apparatus
as is described in the latter of the two specifications above referred to, of
mechanism for correlating the adjustment of the crank-pin, to which the con-
necting-rods of the motor-cylinders are connected, to the adjustment of the valve
by which the flow of fluid through the "short-circuiting" passage is controlled;
other objects of this invention are improved constructions of mechanism for
operating and controlling the short-circuiting valve, and of gear controlling the

page_text: slide-valves of the motor-cylinders: the invention comprises also improvements
relating to the cooling of the circulating fluid and the employment of an
equalizer in conjunction therewith.
In the accompanying drawings.
i
Figure 1 is a plan partly in section on a plane a-a Figure 2, containing
the axis of rotation X Y, of one construction of apparatus according to this
invention, the shaft J having been turned, in Figure 1, through an angle of
180° from the position assumed for it in the laying out of Figure 2, which is
an end elevation of the same apparatus.
Figure 3 is an underside view of the apparatus illustrated in Figure 2.
Figure 4 is a view of a worm-wheel forming part of Figures 1, 2 and 3 with
a portion of the boss removed, the boss being in section on the line 4-4 of
Figure 1.
Figure 5 is a longitudinal central section of part of a power-transmission
apparatus of the kind illustrated in Figure 1, showing to a large scale a con-
struction of the improved gear for controlling the short-circuiting valve and of
improved gear for the valves of the motor-cylinders according to this invention.
Figures 6 and 7 are transverse sections on the lines 6-6 and 7-7 respectively
of Figure 5.
Figure 8 is a view corresponding to a portion (Figure 2) of the drawings
appended to the Specification of the aforesaid prior Letters Patent No. 7479/96
with the addition of an equalizer as hereinafter explained.
Like letters indicate like parts throughout the drawings, and parts in the
present specification corresponding with those in the Specification of the afore-
said prior Letters Patent No. 7479/96 are correspondingly lettered to facilitate
comparison.
With reference first to Figures 1, 2 and 3, K is a "short-circuiting" valve
which may be of any other desired form or construction and operates to vary
the freedom of circulation of fluid in the apparatus in the manner and for the
purpose described in the above mentioned Specification of prior Letters Patent
with regard to the valve K therein referred to.
J is a crank pin to which the movement of the valve K has to be correlated;
it is carried on a secondary shaft J₁ journalled eccentrically within another
shaft C, which affords a long and rigid bearing for it in which it is adjustable,
but in which it is normally prevented from. rotating. By rotating the secondary
shaft J within its long bearing in the shaft C the radial distance of the crank
pin J from the axis of rotation X Y, that is to say its effective throw, can be
varied from the maximum distance, (at which it is shown in the drawing) to
nil, the latter condition obtaining when the secondary shaft J' is so far rotated
as to bring the axis of the crank pin J into coincidence with the axis of
rotation XY. J2 is a worm wheel fixed on the outer end of the secondary
shaft J, so that by a worm the latter can be rotated within the fixed shaft C,
the worm gearing serving also to prevent its accidental rotation.
The parts C, J, J, J2 and K above referred to are arranged to operate like
the parts correspondingly lettered in the aforesaid Specification of prior Letters
Patent No. 7479/96.
One construction of apparatus by which correlation between the adjustment of
the crank pin J and that of the valve K is established will now be described,
assuming for convenience of explanation that the crank pin J is primarily made
to become concentric with the axis of rotation X Y.
On one side of the worm wheel J2 is a spiral tooth J and on the boss of the
worn wheel is a spiral cam J5; this tooth and cam together control the valve K
automatically by means of a lever L, which at one end is connected to a rocker M
pivotted to an extension B3 of the frame B, and provided with teeth M¹ gearing
with the spiral tooth J; the other end of the lever L is connected by a shaft N
to the valve K. The rocker M. will be oscillated by the action of the spiral
tooth J, during rotation of the worm wheel J. L' is a roller carried in the

page_text: lever L at a point intermediate between that at which it is connected to the
rocker M and its opposite end by which it is connected to a manual control
apparatus hereinafter described; this roller bears on the cam J5 and flat face J'
of the boss of the worm wheel.
N is a shaft movable endwise in the secondary shaft J¹ and operatively con-
nected at its inner end to the valve K in the manner hereinafter explained.
The endwise movement of the shaft N is normally automatically effected by the
action of the cam J5 upon the lever L (through the roller L'), and the object of
the spiral tooth J and rocker M is to so move the lever as to keep one part of
it, (the roller L in the present instance) on the parts of the spiral cam J³ or of the
face J of the boss on which that cam is formed, that it may co-operate with that
cam or face in all the different angular positions of the crank pin J, in company
with which the worm wheel J2 and boss J' move; there is, as will hereinafter
appear, a special relationship between the cam J5 and the crank pin J.
The part L of the lever L is slotted or otherwise formed to engage the
shaft N which is provided at its outer end with discs N¹, N³ between which the
part L³ of the lever L is received; the slotted part L of the lever L is provided
so that the engagement of the lever L and shaft N shall not be affected by move-
ment of the lever L in the direction of its own length.
The cam J5 in the present example is one which extends spirally through 360°,
its face sloping gradually down from its highest point J6, in opposite directions
through 180° each way, to merge at each end into the flat face J of the portion
of the worm wheel J2 on which it is placed. The special relationship between the
cam J5 and the crank pin J which consists in the arrangement that the highest
point J of the cam J5 is situated with regard to the axis of the shaft J¹ in a fixed
or constant relationship to the crank pin J is necessitated because when the
crank pin J and axis of rotation are concentric and in what is hereinafter
termed the "neutral" position, the valve K should be wide open and conse-
quently the spiral tooth J4, cam J5, and rocker M and lever L are so disposed
in relation to each other and the crank that when the crank pin is thus concentric
the highest part J of the cam J5 comes against the roller L¹ and therefore the
lever L will have drawn the shaft N outward from the shaft J¹ to one extremo
of its travel, which corresponds with the adjustment of the valve K into a
position giving maximum opening.
It is necessary to the obtainment of the variation in the speed of the casing D
as described in the aforesaid Specification of prior Letters Patent No. 7479 of
1896 that when the crank pin J is moved out of the assumed position of concen-
tricity and "neutrality" in either direction from the assumed starting-point,
the valve K should be slowly closed during the first 180° of such movement,
and should not thereafter commence to reopen but should be kept closed during
any continuation of such movement, say through a further 180° in the same
direction beyond the extent of the first 180° specified. This result is ensured
by making the spiral cam merge into the flat face J7 of the boss of the worm
wheel J at the end of each arc of 180° on either side of the highest portion Jo,
and by so arranging the spiral tooth J* that it moves the lever L'endwise to such
an extent that after causing the roller L¹ to roll upon one or other of the inclined
portions of the cam during the first 180° of the movement of the latter, the
roller is kept, in any continuation of such angular movement, upon the flat
portion J of the worm wheel Ja, from which the shaft N can obtain no movement. .
From the foregoing, and from a consideration of the Specification of Letters
Patent No. 7479 of 1896, it will be evident that the lever L and the flat face J7
are engaged at such times as the valve is to be kept closed, whereas the opening
of the valve is effected by the cam J5, and it will also be seen that the valve K
becomes quite closed upon completion of the first 180° movement of the cam
as aforesaid, and consequently the maximum pressure will be set up within the
apparatus at a time when the crank pin J is so situated that a maximum rota-

page_text: tional effort is transmitted to the casing B by the fluid between the motor
pistons H and the pump pistons D³.
Any further movement of the crank pin brings it in again towards the axis
of rotation X Y and therefore the pressure is maintained, but as the roller L¹
would be upon the flat face J' during such further movement, the valve K will
remain shut, and therefore the speed of the casing D increases the rotational
effort thereof decreasing.
In Figure 1 the wheel J is shown as turned from the position in which it is
shown in Figures 2 and 3 through 180° and the valve K fully closed.
Although in the preceding description the nature and range of the adjustments
of the parts J and K have been specified in detail and the means by which their
correlation is effected are also described in detail with special reference to the
nature and range assumed, it is to be clearly understood that the nature and
range of these adjustments in another machine according to this invention may
differ from those assumed in the example, and that the mechanism for correlating
them will require to be correspondingly modified, any such modification falling
within the ambit of the present invention.
<
As hereinbefore stated it is necessary that when the crank pin J is moved
out of the assumed position of concentricity in either direction, the valve K
should be slowly closed during the first 180° of such movement, and should not
thereafter commence to re-open; it is necessary also that rotation of the cam J5
in the direction in which the worm wheel J2 is moved to give the crank pin J
adjustment regulating the rotation of the casing G in its operation to drive
say a motor car backwards, or astern," that is to say rotation of the cam J5
in the direction of the arrow shown thereon in Figure 2, should be limited in
the present example to an angular movement of not much more than 180°.
Rotation of the cam J5 in the reverse direction (to regulate driving "ahead")
may extend through 360°. The angles of 180° and 360° aforesaid are reckoned.
from the position in which the highest portion Je of the cam J5 is shown in
Figure 2 in relation to the lever L. The reason that such limitation is necessary
will presently be explained. Any convenient mechanism may be employed to
render it impossible that the limits of angular movement above prescribed should
be exceeded. In the construction illustrated by Figures 1, 2, 3, and 4 this
limitation is effected by means of an arm B7 pivotted at B8 to the framing D,
and engaging by means of a pin B9 with a spiral groove J10 (Figure 4)
in the face J of the worm-wheel Ja see Figure 1. The pin B is always in
engagement with the spiral groove, which is closed at its ends, and consequently
the cam J5 and boss J7 cannot be turned through more than the one and a
half turns through which the spiral groove extends.
There are two reasons why a limitation of the astern adjustment of the worm
wheel J and crank pin J are necessary; the first reason is that it is not deemed
judicious to enable the apparatus to be driven backward at a high rate of speed
when it is employed to operate say a road vehicle; the second reason is that when
apparatus operating in the manner described in the Specification of the aforesaid
prior Letters Patent No. 7479 of 1896 is adjusted in going astern, there is a
point in the adjustment of the crank-pin J at which the reaction between the
pump pistons B2 and the pump covers D8 set up by the former and tending to
rotate the casing D in a given direction is exactly balanced by a reaction between
the motor pistons H and the covers of the motor cylinders G tending to rotate the
casing in the opposite direction: under these circumstances any effort exerted
by the engine will tend to burst the casing and will not transmit any rotative
effort to the driven device.
The position of the point in the astern adjustment. of the crank pin J at
which this bursting tendency would arise depends upon the diameters and strokes
of the pump and motor pistons; in the example illustrated it would not occur
within the range of adjustment permitted; in other apparatus the scope per-

page_text: missible for this astern adjustment could be varied in accordance with the.
capacities of the pump and motor cylinders as above explained.
It will be understood that in cases wherein reversal of the motion of the
casing D is conveniently obtainable by reversing the direction of rotation of the
prime mover and therefore of the driving shaft A of the apparatus, the spiral
groove J10 and arm 139 would be so arranged as to limit what might be termed
the new" astern adjustment, (i.e. astern adjustment after reversal of the prime
mover) in like manner to that in which they limited the original astern adjust-
ment. For this purpose there might be a spiral groove extending through
more than the one and a half revolutions before referred to, provided with
screwed studs to block those portions of it which at any time were not required
for use.
Another improvement forming part of the present invention comprises means
which normally keep the lever L above referred to in gear with the cam J5 by
which it is operated, permit it to be operated instantaneously by hand when
desired to instantaneously stop the casing D by short-circuiting through the
valve K the circulating fluid, and return the lever to its proper position on the
cam when released; for instance the end L³ of the lever L can be connected as
shown in Figure 3 to a piston LA. working in a cylinder L5 pivotted at 134 to
the framing B and closed at its outer end by a cover. between which cover and
the piston L is a spring L. This spring tends always to keep, the roller L'
close against the cam J6 or face J7 of the worm-wheel J. L7 is a slotted arm
forming part of the end L³ of the lever L, and receiving a pin L8 in a link L'
arranged to be operated by a lever L10 manually controlled. The pin L8 and
slotted arm L7 are so arranged in relation to each other that whilst the link .L"
can be caused to move the lever L in a such a direction as to draw the shaft N
outward and thereby open the valve K to enable the casing to stop, the link L'
when released by the hand gear will offer no obstacle to the return of the lever L3
by the spring Le into position to bring the roller L¹ into engagement with the
proper portion of the cam J5 or face J7 of the worm-wheel J2; nor will it offer
any obstacle to the subsequent movement of the lever L by the cam. Tho
maintenance of the roller L' opposite its proper place on the boss of the worm-
wheel is ensured even though the wormwheel should be adjusted in an interval
between the removal of the roller from contact therewith and its return to place,
because the lever L is always adjusted endwise to the necessary extent by the
rocker M, whether the roller L' be in contact with the worm-wheel or not.
The rod L18 by which the bell crank lever L10 is caused to actuate the lever L
can be connected to a brake gear if desired so that the act of opening the valve K
results in the simultaneous application of the brake to the casing D or the
apparatus driven thereby.
In order to prevent the occurrence of violent shocks or stresses in various
parts of the apparatus which might ensue upon the sudden restoration of the
lever L to its working position on the cam J5 at times when the relative positions
of the crank-pin J¹ and valve K would render such return injurious, the lever
may be so controlled that it will be impossible for it to go back towards the
cam except when the adjustable crank pin J and the cam are in the neutral
position in which the return of the lever into contact with the face of the cam
could effect no harm. This may be effected by the device illustrated in
Figs. 2 & 3 in which stop or a bolt V is arranged to slide endwise in guides L19
on the face of the lever L, these guides being so formed as not only to permit
the bolt to have movement in the direction of its length but also to have a
slight movement away from the lever in a direction transverse to its length. A
spring Vis arranged to act upon the bolt so as to tend at all times to move
it in the direction of the arrow marked upon it as far as the stop. V2 will allow;
a spring V³ carried upon the bolt is placed in compression between it and the
adjacent face of the lever L so as to tend to move it as far from the lever L
as the guides L₁ permit. On the face J' of the worm wheel J2 is a spiral

page_text: thread J15 of one and a half turns; a finger V on the bolt V ordinarily engages
with the inner circumference J" of the threads J, which, acting upon the
finger V will keep the bolt in the position in which it is indicated by dotted
lines in the drawing until a recessed portion J2 of the thread J15 comes behind
the finger which will then be moved into the recess in the direction of the
arrow shown upon it in Fig. 3, as far as the stop V2 permits. This recess J12
is so situated on the face J' of the worm wheel J2 that when the highest point Jo
of the cam J is acting upon the lever L, or in other words when the lever L
has been moved by the cam Ja to put the valve K in the neutral position pre-
viously referred to the recess J12 is in alignment with and ready to receive the
finger V, which at such a time will be extended into it a short distance towards
the face J by the action of the spring V³; therefore the movement given to
the lever L by the slotted link L must exceed that given to it by the cam J³,
by an amount slightly in excess of that by which the finger V overlaps the inner
circumference of the thread J15, in order that it may be able to free the finger
and the thread as hereinafter explained. If the thread J15 be rotated by rotation
of the worm wheel J2 whilst the finger V is in the recess one or other of the
curved sides J13 of the recess will move the bolt endwise along the lever L in
a direction opposite to that which is indicated by the arrow on the bolt, com-.
pressing the spring V and causing the finger to be pressed by the latter against
the inner circumference J" of the thread; consequently if the lever L is moved
sufficiently far away from the worm wheel at any time after the latter and the
thread J have rotated to move the recess J out of alignment with the finger V4
the bolt will be forced in the direction of the arrow so as to bring the finger
above the top face of the thread, which latter inasmuch as it is recessed only at Ja
will bear against the finger V and become an obstacle preventing the return
of the lever L until the recess J12 is brought once more into alignment with the
finger; to bring the recess into such alignment necessitates readjustment of the
worm wheel J2 and crank J into the neutral position; from the foregoing it will
be seen that withdrawal of the lever L from contact with the cam J5 at any
time at which the crank pin is not in its neutral position makes it necessary
to restore the crank to the neutral position before the lever can be returned to
make the apparatus again operative.
The spring 3 between the bolt and the lever is provided in order that the
finger at such times as it slips over the angle of the thread J15 into contact
with the interior circumference of the latter may be operated by such spring
instead of by the action of the stronger spring Le so that wear of the edges of
that finger and angle is minimised. It is to be clearly understood that for pre-
venting the sudden return of the lever L at times when as above explained
the position of the crank pin J¹ and valve K would render such return injurious,
other automatic devices than that which is above referred to can be adopted,
and made to operate in equivalent fashion.
The means by which the inner end of the shaft N in Figure 1 is enabled
to operate the short-circuiting valve K will now be described:-
A stud R on which the eccentric Q is pivotted (see also Figure 1 of the drawings
appended to the Specification of prior Letters Patent No. 7479 of 1896) is
bored centrally to receive a spindle N movable endwise and connected by the
end No and the levers and links N° N, N1, N2 to the valve K or other device
which is to be adjusted. This spindle No has at its other end a head N with a
circular groove in it; this head is received in the slot of an arm N8 extended
from the rod N which as aforesaid is movable endwise. By imparting endwise
movement to this rod N the spindle N. will also be moved endwise to effect
through the levers and links Nº N°, N", N2, the adjustment of the valve K.
The circular groove in the head N is provided, because when the apparatus is
at work, the parts N' and No have relative rotation.
If desired, instead of operating the valve K by a shaft N which is movable
endwise under the action of a lever that lever or apparatus such as toothed gear

page_text: substituted therefor may be arranged to adjust the shaft N by rotating it instead
of reciprocating it, and any desired mechanism may be used to operatively connect
the inner end of the shaft N. with the valve.
Figures 5, 6 and 7 relate to a construction of control gear for the eccentric
sheave Q alternative to that which is described and illustrated in the Specification
of prior Letters Patent No. 7479 of 1896. It is usually necessary to have the
eccentric sheave in. power-transmission apparatus of the kind to which that and
the present specification relate so arranged and adjustable that although the
crank pin J (Figure 1) has an angular and radial adjustment relatively to the
axis of rotation X Y, a line joining the centre of the pin with that axis shall
always be at right angles to another line joining the axis of rotation with the
centre of the eccentric; i.e., it is necessary to keep the angular advance of the
eccentric constant. In the apparatus illustrated by Figures 4, 5 and 6 the control
gear for the eccentric sheave Q comprises a pinion J8 fixed on the end of an
extension J⁹ from the crank pin J so as to be concentric with the axis of the
crank shaft J. This pinion engages with an internally-toothed ring Q6 secured
to the eccentric sheave Q. The diameter of the pinion J8 on the pitch line is
one half the pitch-line diameter of the internally toothed ring Q, and it follows
therefore that any point on the pitch line of the pinion will describe a straight
line relatively to the ring when the pinion and ring are rotated in gear with
each other; and as it describes a straight line relatively to the ring, it will also
describe a straight line relatively to the sheave Q which is integral with the ring.
The pinion J is so disposed that the axis of the crank pin J passes through
a point in the pitch line thereof, and the ring Q6 is concentric with the axis of
rotation of the apparatus, so that adjustment of the crank pin J by rotation of
the shaft J will cause the ring Q and sheave Q to turn about the stud.R; in this
movement owing to the relative dimensions and arrangement of the gears J8,QG
being such as is described, the crank pin J traverses relatively to a radius passing
from the centre of the eccentric Q to the axis of rotation of the apparatus, a
straight line path maintaining a constant angle with the radius aforesaid, and
also intersecting the axis of rotation of the apparatus so that angular advance
of the eccentric is constant despite the movement of both crank and eccentric
relatively to the stud R in their adjustment.
In every alternate revolution of the crank pin J to and past the axis of rotation
(at which its virtual throw disappears) it will be found that the eccentric which
as now shown has, say, positive advance, will have the advance changed from
positive to negative as the crank pin passes the axial line; consequently the
device could be employed to constitute a reversing-gear applicable to many types
of motor in addition to that to which its application is herein described.
The proportions of the gear-wheels J8 Q6 may be such as to give the eccentric
sheave adjustment in a curve instead of in a straight line.
With reference to Figure 8 it may sometimes be advantageous to insert in the
circulation passages E or their equivalent leading from each valve chamber E
to its neighbours a spring-loaded piston or other equalizing device which will take
up any shocks that may be communicated to the water in those passages, so as to
prevent any irregularity in the effort exercised by the pump piston upon the
circulating fluid being transmitted to the casing D and the apparatus driven
thereby. A spring loaded piston E" of the kind above referred to is illustrated
in Figure 8; it is retained in a small chamber E¹² inserted in one of the circula-
tion passages E5 so that one face of the piston is acted upon by the fluid in
that passage whilst the other is loaded by the spring E13 in compression between
the back of the piston and the outer end of the chamber E¹³, which is in com-
munication by way of the pipe E¼ with one of the passages E' which is open
to the interior of the crank chamber.
The circulation (which in Figure 8 takes place through the passages E5).
might be arranged externally as is suggested in the Specification of prior Letters
Patent No. 7479 of 1896, in which case a diaphragm D would be provided in

page_text: the casing D as indicated by chain lines in Figure 1, and the circulating fluid
passed according to the present invention, through the passages 001 and a
cooler of any convenient construction before returning to the chamber in which
the crank-pin A² rotates.
In apparatus of the kind described the crank-pins of the pump portion of
the device may be made variable by means of "floating" gear of the kind
described and claimed in the Specification of prior Letters Patent No. 6590
of 1896.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is:
1. In power-transmission apparatus of the kind described correlating the
adjustments of the valve K and the crank-pin J for the purpose specified.
2. In power-transmission apparatus of the kind described the combination
with a crank-pin J and valve K of mechanism whereby a correlation such as is
herein before indicated is obtained between their adjustments.
3. In power transmission apparatus of the kind described the combination
with an adjustable crank-pin J and valve K of a cam such as J5 and mechanism
to control substantially as and for the purpose described the adjustment of the
valve K in relation to that of the crank-pin.
4. In power-transmission apparatus of the kind described the combination
substantially as described with the rod N and crank-pin J of a lever L cam
such as J and mechanism for maintaining the lever L in variable relationship
to the cam J5.
5. In power-transmission apparatus of the kind described the combination
with the 'rod N and crank-pin J of a spring or weight controlled lever such as L
cam such as J5 rocker such as M and spiral tooth such as J substantially as
and for the purpose described.
6. In power-transmission apparatus of the kind described the combination
with the crank-pin J and mechanism for adjusting it, of means for limiting
the "astern adjustment for the purpose described.
7. In power-transmission apparatus of the kind described the combination
with a crank-pin J and mechanism for adjusting it of an arm B7 and wheel
or disc such as Js with a spiral groove J10 substantially as and for the purpose
described.
8. In power-transmission apparatus of the kind described the combination
with the valve K lever L and cam J5 of means to prevent the lever after
movement away from the cam from returning towards until the cam is in the
neutral", position aforesaid.
"
9. In power-transmission apparatus of the kind described effecting a prompt
stop by instantaneous short-circuiting substantially as described.
10. In power-transmission apparatus of the kind described the combination
with a spring or weight-controlled lever such as L of a slotted portion L' and
link L, arranged and operating substantially as and for the purpose described.
11. In power-transmission apparatus of the kind described the combination
with the lever L of a stop such as V and recessed spiral thread J5 arranged
and operating substantially as and for the purpose described.
12. In power-transmission apparatus of the kind described the combination
with the lever L of a spring-operated bolt such as V movable along and also
away from the lever for the purpose described.
13. In power-transmission apparatus of the kind described the combination
with the valve K rod N and stud R of a spindle N5 movable endwise and con-
centric with the stud R substantially as and for the purpose described.
14. In power-transmission apparatus of the kind described the combination
with a crank pin J and eccentric sheave Q adjustable about different centres

page_text: of an operative connection between the two comprising hypo-cycloidal gearing
controlling the angular advance of the sheave.
15. In power-transmission apparatus of the kind described the combination
with an adjustable eccentric-sheave such as Q and crank-pin such as J of gears
such as QJ8 one operatively connected to the sheave and the other to 'the
crank-pin substantially as and for the purpose described.
16. În power-transmission apparatus of the kind described the combination
and arrangement of parts constituting the complete gear for adjusting an eccen-
tric Q and valve K substantially as and for the purpose described and illustrated
in Figures 1, 2 and 3 of the accompanying drawings.
17. In power-transmission apparatus of the kind described the combination
and arrangement of parts constituting the complete gear for adjusting an eccen-
tric substantially as described and illustrated in Figures 4, 5 and 6 of the
accompanying drawings.