Improvements in Power Transmitting Mechanisms.
Year: 1899

page_text: Improvements in Power Transmitting Mechanisms.
ANTHONY GEORGE NEW, of "The Voltage," Woking, in the County of Surrey,
Engineer, and REGINALD DONKIN, of Englefield Green, near Staines, in the
County of Surrey, Engineer, and THE ELECTRIC MOTIVE POWER COMPANY, LIMITED,
Engineers, of 74, Caistor Road, Balham, in the County of Surrey, do hereby
declare the nature of this invention to be as follows:-
The object of the present invention, which is particularly applicable to motor-
cars, tramcars and launches, is to provide means by which the relative speed
of a driven wheel or shaft, as also its direction of rotation, may be varied
gradually, while power is being transmitted to it from an engine, motor or
other driving mechanism, whose speed may remain constant.
The invention consists in the application of expanding pulleys, such as those
described in Specification No. 6996 of 1898, to vary the speed at which one por-
tion of an epicyclic train, either having bevel or spur wheels; is caused to.
revolve. The epicyclic train consists of three portions, gearing with one another
and each portion being capable of different relative speed or direction of rota-
tion about a common axis; one form of such epicyclic train is the well-known
differential gear or jack-in-the-box."
"6
It is well known that if one portion of an epicyclic gear, such as that above
mentioned, is caused to revolve at various speeds, and a second portion is caused
to revolve at a constant speed, that the third portion will, in consequence, revolve
at various speeds, remain stationary or change its direction of rotation accord-
ing to the variations in speed (in one direction of rotation) of the one portion.
We are aware that epicyclic gears have been employed to obtain this effect,
but those hitherto known have not been satisfactory, for the purposes above
mentioned; for various reasons, chief amongst which being the absence of suit-
able mechanisms for causing the one driven portion to revolve at various speeds
accurately and without slip.
One, method of carrying our invention into effect is as follows:-
:-
Fixed rigidly to each end of a shaft, which is mounted so that it is capable of
rocking about its axis, is an arm which carries a pulley wheel connected to
rotate together with a chain or spur wheel, in bearings provided on the arm. The
two arms are fixed upon the shaft at an angle of 180 degrees to each other, and
the axes of the two pulleys (and spur or chain) wheels are non-coincident with
the axis of the shaft, but are opposite to one another and parallel with it.
Mounted to revolve freely upon the shaft and rigidly connected together are
(1) a chain, spur or other wheel which is driven by the motor, engine or other

page_text: driving mechanism. (2) a chain or spur wheel, gearing with the chain or spur
wheel connected to the pulley (mounted upon the one arm), and (3) one of the
concentric wheels forming a part of a differential or epicyclic train. Also
mounted to revolve freely upon the shaft is a sleeve which carries at one end
a chain or spur wheel, gearing with the chain or spur wheel connected to the
pulley (mounted on the other arm), and at the other end carries the spider
upon which the intermediate wheels of the differential train are mounted:
Upon this sleeve, and between the wheel and the spider above mentioned, is
mounted to revolve freely an outer sleeve, and this outer sleeve is rigidly
attached both to the other of the concentric wheels forming a part of the
differential train, and also to a chain, spur or other wheel, which imparts motion
to the driving wheels of a vehicle, the propeller shaft of a launch or the like.
Mounted in bearings, which are preferably so arranged as to slide in guides,
and to tend to do so (by reason of springs) in a direction away from the shaft.
above mentioned, is a countershaft arranged at a suitable distance from the above
mentioned shaft and parellel to it. This countershaft carries two expanding
pulleys, one in line with each of the pulley wheels upon the arms of the shaft
first above mentioned. These two expanding pulleys are arranged in such a
manner that as the one is expanded the other is proportionately contracted.
Belts or ropes pass from these two pulleys to the respective pulleys carried by
the shaft, the one transmits power from the engine-driven wheel on the shaft
to the countershaft, and the other transmits this power from the countershaft
to the sleeve on the shaft, which carries the spider in the differential train pre-
viously described. The result of varying the sizes of the two expanding pulleys,
is to tighten the one belt, and to slacken the other, and this tendency causes the
shaft, carrying the pulleys, to rock about its axis, thereby maintaining the
effective tightness of the belts upon their pulleys, while still keeping the chain
or spur wheels, which are connected with these pulleys, in gear with those
mounted concentrically about the shaft.
Since the one pulley on the countershaft expands while the other contracts
the pulls of the two belts as also the centrifugal force acting upon the parts of
the two pulleys themselves tend to balance one another, and consequently we
may use expanding pulleys of a new form in which radially moving sections
of one expanding pulley are connected to corresponding sections of the other
pulley through simple or compound levers, or through levers combined with
a sliding sleeve. In these cases we may either vary the gear ratio, for which
this invention provides, by causing the contraction and expansion of the pulleys
direct or by causing the rocking shaft to move through an angle.
When using expanding pulleys, such as those described in Specification
No. 6996 of 1898, in which a mechanical action, controlled by hand, causes the
pulleys to contract or expand we prefer to arrange one mechanical device for
actuating both pulleys.
By a suitable arrangement of the ratios of the various chain, spurs, bevel and
pulleys wheels the wheel which imparts motion from the outer sleeve about the
shaft, to propel the car, tram, boat or the like may be made to remain stationary
or to revolve at any speed within limits in either direction without altering the
speed at which the motor or engine driven wheel revolves or its direction of
rotation; all these changes can be effected gradually and uninterruptedly, and
are caused solely by allowing one expanding pulley to expand, and the other
to contract.
It must be understood that we do not bind ourselves to any particular form
of epicyclic train, or to any arrangement of connecting mechanisms which are
driven by or drive the three concentrically revolving portions, or their relative
connections to cach portion neither do we bind ourselves to any particular form
of expanding pulleys.
We prefer to arrange a hand control for the expanding pulleys, so that definite
positions of a hand lever will correspond with definite pulley sizes, but we may

page_text: provide means by which a speed governor, either on the driving or engine shaft,
or on the driven or universally moving shaft or sleeve can automatically vary
such control.
We may also combine an automatic control with a 'hand regulator so that
the relative connection between the governor speed, and the pulley sizes can be
varied as desired.
It will be understood that the power transmission mechanism not only con-
stitutes a gradually varying universal gear, but that only a portion of the power
is transmitted through the expanding pulleys and their belts. The bearings
in which the countershaft, above mentioned, revolves are preferably mounted in
guides and provided with springs in order that any stretching of the belts may
be taken up and compensated for automatically or a similar effect may be ob-
tained in any other well known manner such as a spring torsional adjustment
of the arms upon the shaft. It will be also understood that the actual range of
the speed gear can be varied to practically any extent.
".
The expanding pulleys may be mounted on arms on a rocking countershaft,
with a connecting and revolving sleeve about the countershaft (to which sleeve
they are both connected by gearing) between them, in a similar manner to; and
instead of, the pulleys on the shaft arms; in this case ordinary pulleys would
be used concentrically on the shaft.
We may even arrange rocking jockey-pulleys on a separate rocking shaft,
using concentric pulleys on both the shaft and the countershaft, to obtain a
similar result.
Improvements in Power Transmitting Mechanisms.
We, ANTHONY GEORGE NEW, of "The Voltage," Woking, in the County of
Surrey, Engineer, REGINALD DONKIN, formerly of Englefield Green, near Staines,
now of 58, Gap Road, Wimbledon, Engineer, and THE ELECTRIC MOTIVE POWER
COMPANY, LIMITED, Engineers, of 74, Caistor Road, Balham, in the County of
Surrey, 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:-
Our invention which is particularly applicable to motor cars, tramcars and
launchies relates to variable speed gearing so arranged as to enable the relative
speed and the relative direction of rotation of a driven wheel or shaft to bo
gradually varied from zero to a certain maximum while power being trans-
mitted to it from an engine or other driving mechanism, whose speed may remain
constant.
The invention consists of an arrangement by which the speed at which a cer-
tain portion of a differential gear or epicyclic train rotates may be varied with-
out necessitating any variation of the speed of the engine driving it. For this
purpose we arrange upon one shaft two expanding pulleys which are inversely
operated in such a manner that as the one is caused to expand the other is

page_text: caused to contract. Power is transmitted between these expanding pulleys and
two independently mounted wheels, each capable of revolving concentrically
upon another shaft or shafts by means of two belts or their equivalents.. These
two belts run over two pulleys which are mounted eccentrically to the other
liaft or shafts, but which preferably have their axes of rotation parallel to the
axis of rotation of that shaft and which may be carried in bearings upon arms
pivotted about the same shaft. These pulleys which are balanced one against
the other aro each rigidly connected with chain, spur or other gear wheels which
respectively gear continuously with each of the two concentrically' mounted
wheels, upon this other shaft. The bearings which carry the pulley wheels are
.connected together in such a manner that the pulleys are balanced one against
the other so that any movement of the one pulley towards the shaft carrying the
expanding pulleys causes the other pulley to be moved away from that shaft.
By this arrangement both of the driving belts, each of which transmits energy
between one expanding pulley and one eccentrically mounted pulley, are main-
tained at equal tightness altliough the relative sizes of the expanding pulleys
may be varied. It is well known that with, an epicyclic train, composed of
three concentrically revolving parts, the movements of any one part or clement
will depend upon the speed and direction of rotation of the other two parts. If
therefore an epicyclic train is mounted upon the shaft which carries the concen-
trically mounted, pulley-driven; chain or spur wheels above referred to and these
two chain or spur wheels are connected rigidly to two parts of the epicyclic train
respectively then either by driving one of these two elements of the train or by
driving the shaft carrying the two expanding pulleys at a certain speed the third
clement of the epicyclic train will be caused to revolve at certain speeds and
in either direction of rotation or to remain stationary according to the relative
sizes of the two expanding pulleys. We prefer to arrange for the engine to
drive one of the two elements of the epicyclic train rather than to drive the
shaft carrying the two expanding pulleys because in this case only a portion of
the power is transmitted through either of the expanding pulleys or their belts.
For a similar reason, viz, in order to reduce the amount of energy transmitted
through the belts, we prefer to arrange for the engine to directly drive that
element of the epicyclic train which carries the intermediate (or planet) gear
wheels although other methods are also shown in the drawings attached hereto.
We also prefer to arrange for both the engine driven portions of the epicyclic
train to revolve in the same direction. We may use either spur wheels or beve!
wheels in the construction of the epicyclic trains.
"
We are aware that epicyclic trains with cone pulleys and friction disks have
been used for obtaining a similar effect as for example by Houldsworth in his
well known bobbin motion invented by him in 1820 but those hitherto known
have not been satisfactory, especially for transmitting any considerable amount of
power, owing to the inaccuracy and inefficiency of these mechanisms for causing
the necessary variations of speed of its. variably driven parts. We are also aware
that expanding pulleys have been used for obtaining variations in the relative
speed of a driven shaft but as hitherto used it has been necessary to mount these
on separate shafts so that the power is transmitted from the one shaft through
the driving belt between the two pulleys to the other shaft and this has necessi-
tated the use of special devices for maintaining the proper degree of tightness
of the belt while in use. We are also aware that epicyclic trains have been
used in conjunction with two motors or engines, the resultant speed and direc-
tion of rotation being regulated by controlling the speed or speeds of one or
both motors; in the present invention however only one motor is required and
its speed may remain constant or may be varied if desired.
In order to more fully show and describe our invention we will refer to the
drawings attached hereto.
Fig. 1 is a plan view of the transmission gear as applied to a motor-car in

page_text: which the engine drives one portion of an epicyclic gear direct, and in which
the epicyclic gear is arranged about the main driving shaft of the vehicle.
Fig. 2 is an elevation of the same.
Fig. 3 is a plan view of an alternative method, by which the two belts main-
tain an equal relative tightness and in which the epicyclic gear is arranged on
a separate countershaft.
Fig. 4 is an elevation of the same.
Fig. 5 is a similar view to Fig. I but in which the engine drives the shaft.
carrying the expanding pulleys direct.
Fig. 6 is an elevation of the same.
Figs. 6 & 7 are a plan & an elevation showing the details of construction of
the various parts more clearly & illustrating the preferred arrangement of parts.
Referring to Figures 1 & 2, A represents a pinion wheel forming one part of
an epicyclic train and this pinion wheel is connected by means of the sleeve A³
to the differential gear (or jack-in-the-box) A', which is capable of transmitting
differential motion in the usual manner to the driving wheels of the vehicle
through the driving shafts A, A, whose speed and direction of rotation rela-
tively to that of the engine it is desired to vary at will. B and B are two
expanding pulleys mounted upon the shaft B and so arranged that the one is '
caused to contract as the other is caused to expand, by means of the mechanism
operated by the controlling handle B and as more particularly described herein-
after. C and D are two chain wheels mounted freely about the shaft A³.
The wheel C is fixed to a sleeve C which also carries a pinion wheel C³, form-
ing a second portion of the epicyclic train, and a chain wheel C. The wheel D
contains pins upon which pinion wheels D' are free to revolve and these
wheels Di form the third (or planet) portion of the epicyclic train.
Power is transmitted to the chain wheel C from the engine E by the chain Et
and part of the power is then transmitted by the chain wheel C to the expanding
pulley B by means of a chain F which drives a chain wheel F, fixed to a pulley
wheel which is mounted in bearings upon arms which ride freely about
the shaft A, and by means of a belt F. The power transmitted to the expanding
pulley B drives the shaft B and the expanding pulley B' and is then transmitted
by means of the belt G to the chain wheel I by means of the eccentrically
mounted pulley G¹, the chain wheel connected to it G2, and the chain driven by
it G. The pulley G is mounted in bearings carried by the arms G4 which ride
freely about the shaft A
H, H is a chain connected at each end to the arms 13 and G respectively and
this chain passes over pulley wheels H¹, H' which are fixed to the framework
of the vehicle and is provided with a tightening screw II?.
The expanding pulleys shown consist of segments whose ends are carried in
slots in disks mounted about the shaft B. Each end of each segment is carried
in a slot in a disk fixed to the shaft B and in a slot in a disk fixed to a sleeve
mounted freely upon the shaft B. The slots in the one disk are radial and in
the other disk are spiral and hence any relative rotary motion of the disks
causes the pulley segments to recede from or to approach the shaft B.
The sleeve carrying the disks of the expanding pulley B is secured to a
toothed wheel K and the sleeve carrying the disks of the pulley B₁ is secured
to the toothed wheel K. K is a toothed wheel having, nearly but not quite the
same number of teeth as K' and K3 and is fixed rigidly to the shaft B. K³ is
a brake slieave which is free to revolve in bearings upon the sleeves connected
to the wheels K', K; this brake sheave contains a toothed wheel K which is
free to revolve upon a pin secured to the sheave and which meshes with the
three toothed wheels K', K and K. The brake sheave K which tends to revolve
together with the shaft B can be retarded or stopped by means of the hand
lever B and if retarded or stopped will cause the one expanding pulley to expand
and the other to contract owing to the mechanism above described. K is a

page_text: second brake sheave mounted freely about the shaft but connected by means of
a differential or reversing gear K" with the brake sheave K3 in such a manner
that if the sheave K be retarded or stopped. by means of the lever B³ the brake
sheave K is caused to revolve faster than the shaft 13 and lience to cause an
opposite expansion and contraction effect upon the expanding pulleys B1 and B2
to that caused by retarding or holding the brake sheave.K.
The manner in which the speed and direction of rotation of the driving shaft A³
is regulated as desired by means of the controlling lever B is as follows:-The
engine E drives the pinion wheel C, which is one element of the epicyclic train,
at a constant relative speed and is able to drive the pins carrying the planet
pinion wheels at any speed over a very wide range, such speed depending
upon the relative sizes of the expanding pulleys 13 and 133 to the pulleys (1
and the belts G and F which are, crossed belts being maintained at an
equal degree of tightness owing to the chain H which compels any motion of
the one pulley G₁ or F towards the shaft B to cause the other of these two
pulleys to recede from that shaft. If the chain wheel 1 which carries the
pinions '1' is caused to revolve at one half the speed at which the pinion wheel C³
is being driven then the pinion wheel A and consequently the driving shaft A³
will remain at rest whereas if the speed of the chain wheel. D is gradually de-
creased the pinion wheel A will be driven at a gradually increasing speed in
the opposite direction of rotation to that of the pinion wheel C and chain wheel D
and if the speed of 1) is gradually increased the pinion wheel A will be driven
at an increasing speed in the same direction as the pinion C³.
-
Referring to Figures 3 and 4 a similar arrangement of parts and actuated in
a similar manner to that shown in Figures 1 & 2 exists but the epicyclic train
is mounted upon a rocking shaft L and the power is transmitted from the
pinion wheel A to a differential gear L' which is mounted upon the driving
shaft L through the chains L and L' and the countershaft I
In this arrange-
ment of parts a different method of maintaining an equal tightness of the belts
is shewn and consists in mounting the bearings of the pulley wheels G¹ and F
upon arms which are fixed opposite each other as shewn to the shaft L which
sliaft is capable of rocking in suitable bearings and upon which shaft the various
rotating portions of the gear as shown and described are free to revolve.
Referring to Figures 5 & 6, an alternative method of arrangement is shown
and consists of a similar distribution of parts to that shown in Figures 1 & 2
but the power from the engine E is transmitted to the expanding pulley shaft B
by means of the chain M. In this case the speed at which both the engine
driven portions of the epicyclic train, viz. the chain wheel D and the pinion
wheel C, revolve are varied simultaneously when the controlling lever B³ is
operated, the power being transmitted from the shaft B to the epicyclic train
clements D and C through the belts G and F. We do not bind ourselves to
the use of any particular form of expanding pulleys neither do we restrict our-
selves to any particular arrangement of the rocking arms or their equivalent
which cause an equal tension on the two belts, or of the means of taking up
any stretching of the belts. It will be understood that the actual range of the
speed gear can be varied to practically any extent in one or both directions and
that higher or equal maximum speeds in either direction can be provided for.
We prefer to use crossed belts for transmitting the power between the expand-
ing and the ordinary pulleys because when used in this manner the tightness
of the belts remains nearly constant under all working speed conditions but
we may use uncrossed belts.
1)
In Figs. 7 and 8, which are larger scale drawings, the engine E is shown
driving the chain wheel by means of the chain E. The chain wheel E' is
attached to the planet wheel (D) portion of the epicyclic gear 1 by the sleeve C¹,
to which they are fixed. The sleeve C also carries fixed to it the chain wheel C
which drives the pulley F¹ by means of a chain wheel F. The pulley F¹ is

page_text: carried upon hearings in the arms F3, which are -mounted freely about the
shaft A3 and the sleeve C. Power is transmitted to the countershaft B by
means of the belt F, which drives an expanding pulley B. The two expanding
pulleys shown in the drawing are both fixed to the countershaft B and are
inversely operated by the lever B in such a manner that as the one expands
the other contracts; the pulleys are formed of a number of sections S, whose ends
are carried in spiral grooves in disks S¹; these sections $ are also carried in
radial slots in other disks S3; the disks S are fixed rigidly to the shaft B but
the disks S are mounted upon sleeves S³ which are mounted freely about the
shaft and are connected rigidly as shown with spur wheels K and K respec-
tively. The relative rotation of the disks S¹ and the disks Sa cause the pulley
segments to approach or recede from the shaft B and hence to form a larger or
smaller pulley wheel. Between the spur wheels K and K is mounted a spur
wheel K, which is keyed to the shaft B and which has nearly but not quite as
many teeth as the spur wheels K' and K. K³ is a brake sheave which rides
freely about the shaft B and which is fitted with a pinion wheel T and with
an internal planet wheel K³, gearing with the spur wheels K', K and K³. K* is
a second brake sheave mounted freely about the shaft and carrying a pinion
wheel T. K are planet pinion wheels gearing with the pinions T and T,
and are mounted upon a spider which is keyed to the sleeve carrying the spur
wheel K. The action of the lever B³ is to retard and hold the brake sheaves K³
or K when it is desired to expand the one pulley and contract the other pulley
or vice versa; this effect is obtained by virtue of the gearing described above.
Power is transmitted from the expanding pulley B₁ to the pulley G¹ by means
of the belt G. The pulley G is mounted in a similar manner to that already
described in connection with the pulley F¹, power being transmitted from it
to the pinion wheel A of the epicyclic gear by means of the chain wheel G2 and
the chain G; the arms G support the pulley G: The belts F and G are main-
tained at equal tightness by means of the cord H which tends to rock the arms F
and G so as to tighten the belts. The cord H passes round the pulleys H', H¹
and therefore tightens whichever belt may become slack, owing to the action of
the expanding pulleys, and at the same time slackens whichever belt may tend
to become over tight, by the same action.
The planet wheels of the epicyclic gear are driven by the engine direct and
the wheel A can be driven by the engine at varying speeds, it therefore follows
that the pinion wheel C will be caused to revolve at various speeds, to remain
stationary or to revolve in either direction according to the operation of the
lever B. The wheel-C is fixed to a sleeve which connects it rigidly to the
outer portion of the differential gear A'; the wheel is therefore able to drive
the wheels of the vehicle.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that
what we claim is
(1) A variable speed transmission gear comprising the combination of a
pair of inversely operated expanding and contracting pulleys on one shaft, a
pair of plain pulleys connected by belts to the expanding and contracting pulleys
respectively and balanced one against the other to equalize the belt tension and
gear-wheels or their equivalent in continuous engagement with each of the
plain pulleys for the transmission of power; whereby the relative speeds of the
two plain pulleys and of the shaft can be varied by varying the relative sizes of
the expanding and contracting pulleys, for the purposes described.
(2) A variable speed and reversing transmission gear comprising the com-
bination of the elements of Claim 1, and an epicyclic train the gear wheels or
their equivalent being in continuous engagement with any two elements of the
epicyclic train whereby when either of these elements or when the shaft is
driven in one direction by a prime mover the third element is caused to remain

page_text: stationary, to vary its direction of rotation, or its relative speed, by varying the
relative sizes of the expanding and contracting pulleys for the purpose described.
(3) The alternative forms of balanced pulleys and continuously engaging gear
substantially as described and shown in the drawings.
(4) The alternative forms of variable speed and reversing transmission gear
substantially as described and shewn in the drawings.