POTOMONTs in variable Speed Gears.
Year: 1898

page_text: POTOMONTs in variable Speed Gears.
I, ANTHONY GEORGE NEW, of the Voltage, Woking, Surrey, Engineer, do hereby
declare the nature of this invention to be as follows:-
My invention consists of an improved expanding pulley; in the employment
of two or more such improved expanding pulleys on separate counter-shafts when
employed on a motor car or under other conditions where variable speed is
required; of means whereby the belt or equivalent appliance which transmits
motion in this case from one or more of my expanding pulleys to the other or
others is automatically maintained at the proper degree of tightness; and of
means by which when desired the belt may be allowed to slip.
My improved expanding pulley consists essentially of two discs arranged and
fixed a certain distance apart upon a shaft and provided with spiral slots
or grooves on their inner faces. In these spiral slots and between the discs are
arranged a number of rods, one end each in each of the said slots and capable of
movement spirally in the grooves or slots away from or towards the shaft. Between
the spirally slotted or grooved dises and close to them are arranged a pair of
second discs, connected together on a sleeve mounted freely upon the shaft in such
manner as under ordinary circumstances to be capable of revolving regularly with
it. The second discs are provided with radial slots commencing near the centre,
and ending near the circumference. The rods which are moveable in the spiral
slots or grooves in the outer discs pass through these slots there being one rod
through each radial slot. The whole assemblage of rods and discs constitutes a
pulley or an open or partial cylinder. The inner discs which are provided with
the radial slots, though under normal circumstances revolving with the spirally
grooved discs and the shaft are capable while the whole arrangement is revolving
of being moved relatively to the spirally slotted dises either in one sense or in
the other. When this relative movement is caused to take place in one sense the
rods being moved circumferentially by the radial slotted dises are caused by the
action of the spiral slot in which their ends are confined to approach more nearly
to the axle of the pulley, and the diameter of the open or partial cylinder which
they form consequently diminishes. When this relative movement is caused to
take place in the opposite sense the rods are caused to recede from the axle, and
the diameter of the cylinder which they form consequently increases in size. In
order to effect this relative movement I mount a sleeve upon the shaft outside
the fixed discs and to this sleeve I fix the inside radially slotted discs. This sleeve
which is mounted on screw thread on the shaft forms part of or is rigidly con-
nected with a worm-wheel, which in turn engages with the worm.
bearings for which are attached to a feather keyed sleeve on the shaft is provided.
This worm the

page_text: at its end with a star sprocket wheel or equivalent device, which as it revolves
with the whole pulley the shaft and other parts can be made to engage with a
catch or equivalent appliance, which will cause it to turn in one direction or with
a similar catch which will cause it to turn in the opposite direction. The control
of these catches enables me to vary the size of the cylinder formed by the parallel
rods within the limit prescribed by the size of the disc. The screw thread on the
sleeve carrying the worm wheel is attached to the radially slotted discs in such
a manner as to be capable of longitudinal travel which the screw gives it when
the relative movement takes place and this longitudinal travel I arrange so as to
make the star sprocket wheel travel gradually away from whichever catch is causing
it to turn.
By this means I can vary the size of the pulley in proportion to the positions
occupied by the catches.
When employing my improved expanding pulley to obtain a variable gear, for
instance in a motor car or similar vehicle, I prefer to arrange one or more of
them upon one counter shaft, and the same number upon another counter-shaft.
One of these counter-shafts is driven by the engine and the other drives the
vehicle. The catches above described which control the size of the cylinder formed
by the horizontal rods of the pulley, that is to say the effective size of my
expanding pulley is controlled directly or indirectly by hand and is arranged so
as to vary the size of the pulley on the one counter-shaft. Motion is of course
transmitted from the pulley or pullevs on one of the counter-shafts to the other or
others by a flexible belt rope or chain. The bearings of the other counter-shaft
the pulleys on which are preferably and normally not controlled by hand are
susceptible of movement backwards and forwards in guides or equivalently but
are held in a certain position by the action of powerful springs. When I increase
the size of the pulley or pulleys on the one counter-shaft, the effect is necessarily to
tighten the belt, and this puts an increasing pressure upon the bearings of the
other counter-shaft, which causes them to approach the first counter-shaft com-
pressing at the same time the springs which retain its bearings in position. When
a slight movement of this kind has taken place, it brings the change gear of the
expanding pulley or pulleys upon it and namely the star sprocket wheel attached
to the worm above described and the catch which has the effect of diminishing
the effective size of the pulley into contact and so reduces the pressure of the
belt, and this action continues as long as the pressure of the belt is abnormal, and
only ceases when the counter-shaft in its moveable bearings has returned t
approximately its normal position in obedience to the artion of the spring. When
on the other hand the pulley or pulleys on the first counter-shatt are diminished
in size the belt tends to become looser, and the serond counter-shaft retreats from it
under the action of the springs which control its bearings till the change gear
which controls its size is thrown into ertion with the other catel which i perates
that change of gear so as to increase its size until the pressure of the belt or belts
again becomes normal, and brings the counter-shaft into such a position that the
sprocket wheel of the change gear and the catch no longer come into contact. By
the arrangement of the strength of the springs I can control the tightness of the
belt.
When I desire to allow the belt or belts to slip altogether I operate the catch
which varies the size of the pulley or pulleys on the second counter-shaft the
bearings of which are controlled by the springs in such a manner as to cause it to
continuously diminish the size of the pulley or pulleys upon it beyond the point
at which the springs acting on the bearings can continue to come into play, by
which means the diameter of the pulleys is so much diminished that the belt
slips altogether. When I desire again to tighten the belt and to allow the whole
mechanism to operate in its ordinary manner I bring back this catch to its original
position. The rods forming the pulleys or cylinder may be of any convenient 5
Shape but I prefer to make them all in such a manner that their outside working

page_text: faces meet when at their nearest position to the shaft and so that these faces are
all equidistant from the centre.
I do not bind myself as to the arrangement of the spirally or radially slotted
discs relatively to each other or the shaft.
Dated this 2nd dar of March 1808
I, ANTHONY GEORGE NEW, of the Voltage, Woking, Surrey, Engineer, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:-
My invention consists of an improved expanding pulley; in the employment
of two or more such improved expanding pulleys on separate counter-shafts when
employed on a motor car or under other conditions where variable speed is
required; of means whereby the belt or equivalent appliance which transmits
motion in this case from one or more of my expanding pulleys to the other or
others is automatically maintained at the proper degree of tightness; and of
means by which when desired the belt may be allowed to slip by discontinuing the
automatic tightening action temporarily and placing the diminishing catch in
action.
My improved expanding pulley consists essentially of two discs arranged and
fixed a certain distance apart upon a shaft and provided with spiral slots
or grooves on their inner faces. In these spiral slots and between the discs are
arranged a number of rods, one end each in each of the said slots and capable of
movement spirally in the grooves or slots away from or towards the shaft. Between
the spirally slotted or grooved discs and close to them are arranged a pair of
second discs, connected together on a sleeve mounted freely upon the shaft in such
manner as under ordinary circumstances to be capable of revolving regularly with
it. The second discs are provided with radial slots commencing near the centre,
and ending near the circumference. The rods which are moveable in the spiral
slots or grooves in the outer discs pass through these slots there being one rod
through each radial slot. The whole assemblage of rods and discs constitutes a
pulley or an open or partial cylinder. The inner discs which are provided with
the radial slots, though under normal circumstances revolving with the spirally
grooved discs and the shaft are capable while the whole arrangement is revolving
of being moved relatively to the spirally slotted discs either in one sense or in
the other. When this relative movement is caused to take place in one sense the
rods being moved circumferentially by the radial slotted dises are caused by the
action of the spiral slot in which their ends are confined to approach more nearly
to the axle of the pulley, and the diameter of the open or partial cylinder which
they form consequently diminishes. When this relative movement is caused to
take place in the opposite sense the rods are caused to recede from the axle, and
the diameter of the cylinder which they form consequently increases in size. In
order to effect this relative movement I mount a sleeve upon the shaft outside
the fixed dises arranged in such a manner that the sleeve in turning about the shaft
turns the inside radially slotted discs. This sleeve, which on the non-
automatically controlled pulley or pulleys is mounted on a screw thread
on the shaft, is provided with a worm-wheel or is rigidly connected
to a worm-wheel, which in turn engages with a Worm. This worm the
bearings for which are attached to a feather keyed sleeve on the shaft is provided

page_text: at its end with a star sprocket wheel or equivalent device, which as it revolves
with the whole pulley the shaft and other parts can be made to engage with a
catch or equivalent appliance, which will cause it to turn in one direction or with
a similar catch which will cause it to turn in the opposite direction. The control
of these catches enables me to vary the size of the cylinder formed by the parallel
rods within the limit prescribed by the size of the disc. The sleeve carrying the
worm wheel on the non-automatically controlled pulley is attached to the radially
slotted discs in such a manner as to be capable of longitudinal travel which the
screw gives it when the relative movement takes place without transmitting longi-
tudinal motion to the discs and this longitudinal travel I arrange so as to make
the star sprocket wheel travel gradually away from whichever catch is causing it
to turn. The sleeve carrying the worm-wheel on the automatically controlled
pulley does not require this travel and may consequently be mounted freely on
the shaft but incapable of longitudinal travel.
By this means I can vary the size of the hand adjusted pulley in proportion to
the positions occupied by the catches.
When employing my improved expanding pulley to obtain a variable gear, for
instance in a motor car or similar vehicle, I prefer to arrange one or more of
them upon one counter shaft, and the same number upon another counter-shaft.
One of these counter-shafts is driven by the engine and the other drives the
vehicle. The catches above described which control the size of the cylinder formed
by the horizontal rods of the pulley, that is to say the effective size of my
expanding pulley is controlled directly or indirectly by hand and is arranged so
as to vary the size of the pulley on the one counter-shaft. Motion is of course
transmitted from the pulley or pulleys on one of the counter-shafts to the other or
others by a flexible belt rope or chain. The bearings of the other counter-shaft
the pulleys on which are preferably and normally not controlled by hand are
susceptible of movement backwards and forwards in guides or equivalently but
are held in a certain position by the action of powerful springs. When I increase
the size of the pulley or pulleys on the one counter-shaft, the effect is necessarily to
tighten the belt, and this puts an increasing pressure upon the bearings of the
other counter-shaft, which causes them to approach the first counter-shaft com-
pressing at the same time the springs which retain its bearings in position. When
a slight movement of this kind has taken place, it brings the change gear of the
expanding pulley or pulleys upon it and namely the star sprocket wheel attached
to the worm above described and the catch which has the effect of diminishing
the effective size of the pulley into contact and so reduces the pressure of the
belt, and this action continues as long as the pressure of the belt is abnormal, and
only cases when the counter-shaft in its moveable bearings has returned to
approximately its normal position in obedience to the action of the spring. When
on the other hand the pulley or pulleys on the first counter-shaft are diminished
in size the belt tends to become looser, and the second counter-shaft retreats from it
under the action of the springs which control its bearings till the change gear
which controls its size is thrown into artion with the other catch which operates
that change of gear so as to increase its size until the pressure of the belt or belts
again becomes normal, and brings the counter-shaft into such a position that the
sprocket wheel of the change gear and the catch no longer come into contact.
the arrangement of the strength of the springs I can control the tightness of the
belt.
By
When I desire to allow the belt or belts to slip altogether I disconnect the
mechanical control temporarily between the catch which varies the size of the
pulley or pulleys on the second counter-shaft and the bearings which are con-
trolled by the springs and actuate the catch by hand in such a manner as to cause
it to diminish the size of the pulley or pulleys upon it beyond the point at which
the springs acting on the bearings can continue to come into play, by which
means the diameter of the pulleys is so much diminished that the helt slips
altogether. When I desire again to tighten the belt and to allow the whole
mechanism to operate in its ordinary manner I reestablish the mechanical auto-

page_text: matic control and bring back this catch to its original position. I may however
dispense with this method and use a clutch to obtain the same result. The rods
forming the pulley or cylinder may be of any convenient shape but I prefer to
make them all in such a manner that their outside working faces meet when at
their nearest position to the shaft and so that these faces are all equidistant from
the centre.
In order that the nature of this invention may be more fully understood, refer-
ence is made to the accompanying drawing, in which a sectional plan of my
arrangement is shown.
S and S' are the two counter-shafts on which are mounted the expanding pulleys
with their connected gear and appliances. The bearings of the one shaft S are
as shown rigidly secured to the undercarriage or framework F of the vehicle;
while the bearings 61 of the shaft S are secured to blocks OO which are suscep-
tible of movement backwards and forwards in guides gg. The blocks 00 are
secured to the system of levers which are in turn attached to the spiral
springs RR.
The expanding pulleys on each of the shafts SS₁ consist of horizontal rods and
of the discs dddd. The discs dd are provided with spiral slots rr shown in
section. The discs d' d' which are provided with radial slots are situated as shown
inside the discs dd. The rods on which the belt run pass through the radial
slots their heads or ends reposing in the spiral slots r r.
The discs d d form part
of or are rigidly secured to a sleeve s which is keyed to the shaft. One end of it
is provided with a screw thread in the hand adjusted pulley and a set of thrust
rings in the automatically adjusted one which engages with a corresponding thread
or set of thrust rings in an outer sleeve s which latter is divided into two portions
forming a clutch; the one portion being bolted to the plate and the other
carrying the worm w which engages with a worm-wheel forming part of a pinion
wheel, which in turn engages with a pinion wheel attached to the large sprocket
wheel H. The plate is bolted to the radially slotted disc d which are further
connected together rigidly by the loose collar m. K and K are catches con-
nected with the levers LL. These catches may be made to engage with the
sprocket wheel H either right or left as it comes round or may be made to miss
it altogether.
When the hand lever L is moved in one direction the sprocket wheel H engages
at each revolution on one side with the catch K, turning it a certain amount.
This causes a partial revolution of the pinion and consequently of the worm w.
This in turn causes a partial revolution of the sleeve s¹, causing it to screw along
the sleeves and moving the worm w and wheels h and H away from the catch K
and causing the portion of the sleeve s¹ which is bolted to the plate p, and in
consequence the discs d'd', to revolve a certain amount relatively to the spirally
slotted dises d d. This movement is the same as that familiarly known and used
in the common scroll chuck. It has for a result to vary the distance of the rods
forming the belt driving surface of the pulley from the axle or shaft, and con-
sequently varying its size. When the wheel H is caused to revolve in the opposite
direction owing to the lever L being moved in the other direction and the catch K
engaging in consequence with the opposite side of the wheel H these motions are
reversed causing the two parts of the sleeve s¹ to be withdrawn from one another
until the required pulley diameter is obtained, and the wheel H moved out of con-
tact with the catch K and also causing the relative motion of the discs d' d'
and to be reversed and the distance of the rods from the axle or shaft and in
consequence the working size of the pulley to be altered in the opposite sense
to the required extent (according to the position of the hand lever L).
Instead of effecting these movements by means of the worm-wheel and gear
shown in the drawing I may make the shaft S hollow and operate clutches in the
sleeve s by hydraulic means.
The inter-action of the two similar expanding pulleys on the shafts SS¹ is as
follows:-When the expanding pulley on S is increased in size in the manner

page_text: above described the belt is of course proportionately tightened. This exercises a
forward pressure upon the shaft or counter-shatt S tending to pull it forward-a
tendency to which its bearing, mounted on the sliding blocks which as pre-
viously explained are connected by the levers to the spiral springs R R enable
it to vield. This has the effect of causing the lever L which is fixed to the
bearing to operate the catch to engage with the wheel H of its expanding
pulley in such a manner as to make the said expanding pulley smaller. When on
the other hand the size of the expanding pulley mounted on S decreases the belt
becomes slackened, and the blocks oo yielding to the action of the spiral
springs R R are drawn back causing the catch K to operate its expanding pulley
so as to increase its diameter. In this way the belt is always kept tight, and
a varying gear obtained.
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. The method of increasing or diminishing the effective size of expanding
pulleys by the relative movements of radially and spirally slotted discs, through
which pass the rods forming the working surface of the pulley.
2. The employment of the means shown and described for causing the variations
in size of one expanding pulley connected to or driving another by means of a
belt or equivalent appliance to vary the diameter or size of that other expanding
pulley in a corresponding degree so as to produce a varying gear and to keep the
belt or equivalent appliance always tight.
Dated the 22nd December 1898.