Improvements in and connected with Variable Throw Cranks.
Year: 1899

page_text: Date of Application, 10th Oct., 1899-Accepted, 3rd Feb.,
1900
COMPLETE SPECIFICATION.
Improvements in and connected with Variable Throw Cranks.
I, GEORGE CROYDON MARKS, of 18, Southampton Buildings. Chancery Lane,
London, W.C., Consulting Engineer and Chartered Patent Agent (being a
communication from John Potter Murphy, of Aldine Hotel, Philadelphia, Penn-
sylvania, United States of America, General Superintendent), 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:―
My invention relates to mechanism for transmitting power and particularly
to mechanism for transmitting power with variable speed. My invention has
to do particularly with that type of varying speed transmitting devices in which
the power is transmitted through a crank pin of variable eccentricity and the
leading feature of my invention has to do with the provision of improved
mechanism for adjusting the eccentricity of the crank pin, the movements of
which, to and from the centre about which it moves, I control by means of an
hydraulic cylinder seated in the crank disc of the engine and a plunger moving
in such cylinder and in turn controlling the position of the crank pin.
In connection with the hydraulically controlled crank pin, a further object of
my invention is, to balance the weights in the crank pin disc;-to provide in a
convenient way for the entrance and exhaust of the motive fluid to the hydraulic
cylinder aforesaid;-to provide convenient and effective actuating mechanism
for the control of the crank pin;-to provide an effective braking device for
checking the motion of the engine when desired and generally to perfect and
adapt the mechanism for successful use.
The nature of my improvements will be best understood as described in con-
nection with the drawings in which they are illustrated and in which
Figure 1 is a side elevation of an automobile vehicle equipped with my
improvements which are especially, though not exclusively, adapted for this use.
Figure 2 is a side elevation on an enlarged scale of the pump which I use for
controlling the position of the crank pin."
Figure 3 is a plan view of this pump and
Figure 4 a cross-sectional view taken as on the section line 4-4 of Fig. 2.
Figure 5 is a plan view of the engine which I have illustrated in connection
with the devices to which my invention peculiarly relates.
Figure 6 is an enlarged plan view of the crank shaft of the engine and its
immediate connections shown partly in central longitudinal section.
Figure 7 is a face view of the crank pin disc.
Figure 8 a cross sectional view taken on the line 8-8 of Fig. 7.
Figure 9 a cross sectional view taken on the line 9-9 of Fig. 7.
Figure 10 is a face view of a modified form of crank pin disc shown partly
in section as on the line 10-10 of Fig. 11.
Figure 11 is an edge view of the modified crank disc shown partly in section
taken as on the line 11-11 of Fig. 10 and
Figure 12 is again a section through the modified crank pin disc taken as on
the section line 12-12 of Fig. 10.

page_text: R, Fig. 1, indicates the body of the wagon which is supported in the usual
way on the running gear in which the front and rear axles are connected by a
truss frame, the compression members of which are indicated at, R¹ and the
tension members at R2, R3 indicating the front bolster to..which the ends of the
truss members are attached and R the front axle or rather axles because stud
axles are usually employed; R³ the rear axles to the axle boxes of which the
rear ends of the truss frame may conveniently be connected. R6 R6 indicate
struts connecting the members R¹ and R2 as indicated. R7 indicate ears or
projections only one of which is shown in the drawing, which are formed on a
cradle bar R8 and which are secured on the front struts R. In a similar
way R, Fig. 1, indicates an ear or projection on a cradle bar R10 (see Fig. 5)
which has two such ears one connected with each of the rear struts:R6; the cradle
bars are thus free to move up and down on the struts but are elastically held
in position by springs as clearly shown in Fig. 1. The cradle bars R8 Rio sup-
port the casing N of the engine (see Figs. 1 and 5) the casing having a projec-
tion N8 in front by which it is secured to the cradle bar R8 while the cradle
bar R10 is carried in a Ụ shape under the body of the casing. E, see Fig. 1,
indicates a crank pin ariven by an engine contained in the casing N and con-
necting with rods Q and Q¹ one of which connects with an upwardly and the
other with a downwardly extending clutch lever Q2, each such lever controlling
the movements of one of the clutches indicated at Q3 and which, in any con-
venient way, are adapted to engage the rear axle R³ when moved in one direction
and to move freely on the casing in the other direction. The parts above described
do not form a part of my present invention, though in some features they involve
features of construction which I believe to be new with me and which form
the subject-matter of my co-pending application, No. 20326 filed 10th October
1899.
A, Fig. 6, indicates one end of the crank shaft of the engine which, as shown,
is formed with a threaded extension A¹ of smaller diameter. The other end of
the crank shaft is indicated at A3, A3 and A4 indicating the cranks and a con-
tinuous channel A2 being formed through the shaft and cranks, as clearly indi-
cated, the said channel, however, in the portion A5 of the shaft merging into
a cylindrical enlargement A which in turn merges into a still further enlarge-
ment indicated at A7 A8, the portion A8 being internally threaded. As shown
the extreme outer end of the portion As of the shaft is provided with an exter-
nally threaded projection A". B, Figs. 6, 8 and 9, is a central projecting stud
on the rear face of the crank disc having a perforation at its end adapted to
receive the end A of the shaft and a threaded extension B' into which the
threaded end A¹ of the shaft screws as shown in Fig. 6. N' and N¹ Fig. 6
indicate bearings for the crank shaft formed in the casing N, N2 Na indicating
hard steel bearing liners and N³ rollers. e indicates the crank disc proper
which in my preferred construction I provide with a steel or iron rim or tire, so
to speak, C. In the disc c I form a cylinder C¹ which may conveniently extend
through the disc proper c as clearly shown in Figs. 7, 8 and 9, the cylinder
lying transversely through the centre of the disc and being provided with a
slot C on the front of the disc. On each side of the central cylindrical passage
I form in the disc c parallel passages which may conveniently also be cylindrical,
as indicated at C3 C3, and at convenient points, preferably at right angles and
through the centre of the disc I form connecting passages C* C* opened toward
the face of the disc and provided with journal bearings C5 at their bottom.
C6 C6 indicate blocks or plates for closing the face of these openings C which
are formed with journal bearings C7 facing the bearings C5 as is best shown
in Fig. 9. C indicates a port or channel formed in the disc c opening near the
periphery of this disc into the cylinder C¹, as shown in Fig. 8, and at the centre
of the disc into the projecting stud B so as to communicate freely with the
channel A2 in the crank shaft. D is a plunger fitting and moving in the
cylinder C¹, and, as shown, formed with a threaded perforation D' into which

page_text: screws the crank pin E, the position of this perforation being preferably such
that when the cylinder D is at the bottom of its stroke the perforation will.coin-
cide with the centre of the crank pin disc. The plunger D is formed with racks
indicated at D2 D2, Fig. 7, formed on its opposite sides and, as shown, it is also
formed with a spring receiving cup 13 on its inner end. Findicates a powerful
spring situated in the portion of the cylindrical passage opposite to that in which
the plunger works and arranged, as shown, to act against the plunger and hold
it normally in the position indicated in Figs. 7 and 8. G G, Figs. 7. and 9,
are counterweights moving in the passages C³ C³ and formed with racks G. on
their faces lying opposite to the plunger D. H H are spur wheels situated in:
the passages C and provided with journals which fit into the journal bear::
ings C and C as shown in Fig. 9. These spur wheels are of a size and character;
to engage with their teeth in the opposite racks D2 and G' so that any movement
of the plunger. is necessarily concurrent with a movement of the counterweights
in the opposite direction. I is a face plate secured to and moving with the crank
pin E in a groove formed on the face of the disc, the plate being of dimensions.
and character. tis indicated in Figs. 7 and 8 to cover the slot C. It will be
obvious that any fluid introduced under sufficient pressure through the channels A³
and C will force the plunger D to move in the cylinder Covercoming the force
exerted by the spring F and moving the crank pin E further away from the
centre of its disc and that the movement of the crank pin as already noted will
automatically shift the position of the counterweights which are arranged to
balance the other moving parts contained in the disc and maintain the weight
of the whole in a substantially balanced condition. A relaxation of the pressure,
by permitting the fluid to escape, permits the powerful spring F to move the
plunger back, to or toward its normal position shifting the position of the crank
pin nearer to the centre of the disc. The best method known to me for admitting
and exhausting the fluid which controls the position of the crank pin is through
the crank shaft of the engine, as indicated in Fig. 6, and where this method is
availed of I carry the fluid from a pipe K leading from the pump or other device
where the necessary pressure and motion is given to the fluid, through channels N'
and N formed in a bracket N' of the engine casing N. The channelled bracket N
has a perforation №5 at its end in line with the perforation A in the portion A³
of the crank shaft and into this perforation N5 I screw a pipe O having threads 03
at its outer end and conveniently a jam nut 06, the said pipe extending through
the threaded perforation A8 and into the cylindrical perforation A6 with which
it makes a nice fit. The portion 02 of the pipe which fits in the cylinder A6
is formed with a multiplicity of annular channels which on well known prin-
ciples have the effect of preventing leakage. I also prefer to form the pipe O
with a collar 01 which will fit against the shoulder A7 formed between the por-
tions A and A8 and to secure the pipe O in proper position in the crank shaft I
employ a long heel nut-indicated at 05 which screws into the threaded perfora-
tion A as shown.
0
Referring at this time to parts shown in connection with Figs. 5 and 6 but not
forming any, part of my present invention I will state that P is a worm wheel
which operates a shaft P¹ which through a universal connection På rotates a
shaft. P³ controlling the cams which regulate the admission and exhaust of the
engine. P indicates a governor which by connection P5 and a further connec-
tion Po operates to regulate valves of the engine and P7 is a clutch starting
device for setting the crank shaft in motion and starting the engine, this device
being held in place by a plate 04 and a nut 07 screwing on the threaded nut A'
of the shaft. The engine and other appliances thus partially indicated form the
subject matter of another application for Letters Patent No. 20323 filed, 10th
October 1899, and are partially shown in the present case merely because in actual
practice I have used the devices to which this case especially refers in connection
with the said engine and appliances and in the manner indicated in the drawings,

page_text: Referring now to Figs. 1, 2, 3 and 4 it will be noticed that the pipe K¹ to.
which reference has already been made leads to the pump cylinder indicated at J.
This pump cylinder is formed with an admission port J and an exhaust port J2,
the admission port leading through a valve box J3 containing a non-return
valve J5, into a supply pipe K, leading to a reservoir such as indicated, for
instance, at k in Fig. 1. The delivery port J2 leads through a valve box j³ also
provided with a non-return valve J and through a second valve box J' into the
pipe K¹. A port J connects the valve boxes J3 and J7 through a port or passage
which is normally held closed by a valve JB. L indicates the plunger working in
the cylinder and connected by means of a universal joint indicated at L' with
a plunger rod L2 which in turn connects with the lower end L3 of a lever L³ L+.
pivoted at L5 and the upper end L of which is in convenient reach of the driver's
seat as shown in Fig. 1. The valve J8 is connected with a stem M having secured
to its free end a downwardly extending arm M¹, see Fig. 2, having rearwardly
extending arms M² M². M³ is a shaft secured in bearings firmly connected with
the pump cylinder J and having at one end a cylindrical portion M. which lies
between the arms M2 M² and an upwardly extending lever arm M5 as well as a
cam indicated at m³ which presses against the portion of the arm M lying between
the arms M² M². At the other end of the shaft M3 is secured the hub M6 of a
lever M which in turn is secured to a rod M connected at its upper end with a
lever M which as shown is a foot lever and is easily reached from the driver's
seat, see Fig. 1. To the upper end of the lever M is secured a rod M8 which runs
backward under the wagon body, as shown in Fig. 1, and is connected with a
lever to which is fastened a brake band M2 working on a brake drum Q2 as
indicated at the right hand side of Fig. 1.
When the operator desires to move the crank pin E outward from the centre
of its disc and thus to increase the throw of the clutches controlled by it he
moves the lever L L3 so as to operate the plunger L drawing fluid, which will
conveniently be oil, from the reservoir k through the pipe K and the valve J³
into the cylinder J and forcing it out through the port J and valve into the
conduit K and thence through the passages described into the cylinder in the
crank pin disc. When on the other hand he desires to arrest or lessen the stroke
of the clutches he places his foot on the foot lever M10 moving the lever M7
downward and rotating the shaft M³ toward the left, this motion of the shaft
presses the cam m against the rod M¹ and pushes it and the rod M inward
through the rod M lifting the valve Ja from its seat and permitting the flow of
the liquid backward from the pipe K¹ through the valve box J7 and port J into
the reservoir, the force of the spring in the crank disc as soon as the hydraulic
pressure is relieved forcing the crank pin back to its central and inoperative
position, at the same time in the construction shown the movement of the
shaft M³ acting through the lever M5, rod M8 and lever M applies the brake to
the rear or driven axle of the vehicle, and it will be seen that by the mechanism
I have described I can at all times regulate the operation of the motor upon the
rear axle or other driving shaft of the machine without in any way checking or
arresting the motion of the motor.
I have shown in Fig. 1 a lever S within easy reach of the driver's seat which
is pivoted at $8 and formed with an extension $7 connecting through a rod S
with a lever S which in turn operates a shaft Shaving secured to its lower
portion arms S³, the purpose of which is to actuate a device acting directly upon
the clutches and by which they are adjusted either to an inoperative position or
to a position in which they operate in opposite directions. These devices form the
subject matter of a co-pending application No. 17503 filed 29th August 1899
and need not therefore be further described or illustrated in the present case.
In the figures of the drawings heretofore specifically referred to I have shown
what I believe to be the best construction for operating the adjustable crank pin,
the mechanism described, however, is capable of many modifications without
avoidance of my invention, and in Figs. 10, 11 and 12 I have illustrated onė

page_text: such modification. In these figures I have shown the disc c with a central trans-
verse cylinder Co and parallel lateral passages C¹³ and have also illustrated the
plunger as situated in the central cylinder and the counterweights in the lateral
passages, the plunger and counterweights being operatively connected as before
by means of spur wheels H. In the modified construction, however I have
shown instead of a spring F acting directly on the plunger two springs f f acting
directly on the counterweights but of course indirectly on the plunger in the same
way as before. In place however of a single channel C8 leading to one end of
the cylinder Co I have in the modification shown two channels 18 leading to
opposite ends of the cylinder Co and connecting with two channels a¹ formed
through the crank shaft of the engine. In such a device as this the pump used
for controlling the position of the crank pin will draw from one side of the
cylinder what it forces into the other side, but for obvious reasons is less con-
veniently practicable than the construction which I have previously described.
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. A rotary head having a transverse cylinder formed in it inside the plane of
its outer face in combination with a plunger movable in the cylinder, a crank
pin secured directly to said plunger and so as to project from the outer face of
the head, a driving shaft for actuating the head, and channels for introducing
and exhausting pressure fluid to and from the cylinder to move the plunger and
adjust the eccentricity of the crank pin, said channels being formed in the shaft
and head aforesaid.
2. A rotating head having a transverse channel formed in it said channel
comprising a cylinder at one end, a plunger movable in the cylinder aforesaid
and having a crank pin secured in it, resilient means secured to the head and
arranged to exert its force against the plunger to force it home in the cylinder
and a channel for fluid under pressure leading to the outer end of the cylinder.
3. A rotating head having a transverse channel formed in it said channel com-
prising a cylinder at one end and a spring chamber at the other, a plunger movable
in the cylinder aforesaid and having a crank pin secured to it, a spring situated
in the spring chamber and acting against the end of the plunger to force it home
in the cylinder, and a channel for fluid under pressure leading to the outer end
of the cylinder.
4. A rotary head in combination with a transversely movable slide having a
crank pin secured thereto, transversely movable counterweight mechanism, means
connecting the crank-pin-slide and counterweight mechanism as described and
so that they will move simultaneously and so as to balance each other and the
head as a whole, and means for moving the slide to adjust the eccentricity of
the crank pin.
5. A rotary head in combination with a transversely movable slide having a
crank pin secured thereto, transversely movable counterweight mechanism,
means connecting the crank-pin-slide and counterweight mechanism as described
and so that they will move simultaneously and so as to balance each other and
the head as a whole, resilient means arranged to oppose the movement of the
pin away from the centre of the head, and means for moving the slide to adjust
the eccentricity of the crank pin.
6. A rotary head in combination with a transversely movable slide having a
crank pin secured thereto, two counterweights, each moving in guides in the
head parallel to the crank-pin-slide and one on each side of said slide, racks
formed in or secured to the opposite side of the slide and counterweights, pinions
journalled in the head between the slide and counterweights with their teeth in
engagement with the racks and means for actuating the slide and through it
the pin and counterweight.

page_text: A rotary head in combination with a transversely. movable slide havingia
crank pin secured thereto, two counterweights, each. moving in guides in the
head. parallel to the crank-pin-slide and one on each side of said: slide, racks
formed in or secured to the opposite sides of the slide and.counterweights, pinions
journalled in the head between the slide and counterweights with their teeth in
engagement with the racks, resilient means arranged to oppose the movement of
the pin and connected parts away from the position they occupy when the pin
is at the centre of the head, and means for actuating the slide and through it the
pin and counterweights.
8. The rotating head c. having a central transversely extending cylinder..C
and lateral parallel channel's C C³, a slot C³ formed in the face of the head
leading into cylinder C, connecting passages C* C* between the cylinder C
and the channels. C3 C3 and a fluid channel C leading to one end of cylinder. CL
in combination with a plunger working in the cylinder C₁ and having a crank
pin E attached to it and projecting through slot C, counterweights working in
channels CC3, the plunger and counterweights having their opposite sides
provided with racks, and spur wheels H H journalled in passages C4 C4 having
their teeth in engagement with the racks aforesaid.
19. The rotating. head having a central transversely extending cylinder, C
and lateral parallel channels C³ C³, a slot C2 formed in the face of the head
leading into cylinder C, connecting passages C C between the, cylinder. C'
and the channels C3 C3 and a fluid channel C8 leading to one end of cylinder C¹
ini combination with a rim C surrounding the head a plunger working in the
cylinder and having a crank pin E attached to it and projecting through
slot C³, counterweights working in channels C3 C3, the plunger and counter-
weights having their opposite sides provided with racks, and spur wheels H H
journalled in passages CC having their teeth in engagement with the racks
aforesaid.
'
10. The combination with a head having a transverse cylinder formed in it
and a channel formed in the head leading from its centre to one end of the
cylinder aforesaid, a shaft secured to the head and having a channel. formed
through it said channel connected with the channel in the head at one end, and
with a cylindrical enlargement A6 at the other end of the shaft, a fixed tube O
having a portion 02 fitting in cylinder A6 and formed with a multiplicity of
annular grooves on its outer surface and a support for the outer end of the tube
having a port as №6 in communication with the end of the tube.
11. In combination with a head having a transverse cylinder formed in it
and a channel formed in the head leading from its centre to one end, of the
cylinder, aforesaid, a shaft secured to the head and having a channel; formed
through it said channel connecting with the channel in the head at one end and
with an inner cylindrical enlargement A6 and through said enlargement.A
into an outer larger and threaded enlargement A8 at the other end of the shaft,
a fixed tube O having a portion 02, fitting in cylinder A and formed with
multiplicity of annular grooves on its outer surface, an annular shoulder O
adapted to rest on a shoulder A' at the end of enlargement As, a threaded tubular
bushing 05 screwing into the enlargement A8 and around tube O, and a support
for the outer end of the tube having a port as No in communication with the end
of the tube.
12. In combination with a rotating head having a transverse. hydraulic
cylinder formed in it and a crank pin actuating plunger movable therein,
resilient means tending to force the plunger home in its cylinder and to hold the
pin in or about a central position, a channel leading to the end of the cylinder in
the head, a reservoir of liquid, a pump cylinder connected to said reservoir and
to the channel leading to the cylinder in the head, a plunger working in the
pump cylinder, valves arranged as described and so that the plunger will draw
liquid from the reservoir and force it into the cylinder in the head, a port con-
necting the delivery passage of the pump and the reservoir, a normally seated

page_text: valve for closing said port, means for opening said valve at will and means for
actuating the pump plunger.
13. In combination with a rotating head having a transverse hydraulic cylinder
formed in it and a crank pin actuating plunger movable therein, mechanism
driven by said crank pin including a brake drum, a brake arranged to check
the movement of said mechanism by pressure on said drum, resilient means
tending to force the plunger home in its cylinder and to hold the pin in or about
a central position, a channel leading to the end of the cylinder on the head, a
reservoir of liquid, a pump cylinder connected to said reservoir and to the
channel leading to the cylinder in the head, a plunger working in the pump
cylinder, valves arranged as described and so that the plunger will draw liquid
from the reservoir and force it into the cylinder in the head, a port connecting
the delivery passage of the pump and the reservoir, a normally seated valve for
closing said port, a lever arranged when actuated to simultaneously open said
valve and apply the brake and means for actuating the pump plunger.
1
1000
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
13, Temple Street, Birmingham, and 25, Cross Street, Manchester, Agents.