Improvements in Driving and Brake Mechanism for Cycles.
Year: 1899

page_text: Date of Application, 'st Aug., 1899
Complete Specification Left 1st May 1900-Accepted 2nd June 1900
PROVISIONAL SPECIFICATION.
Improvements in Driving and Brake Mechanism for Cycles.
We, WILLIAM HENRY TOMKIES, of 4, Fort Buildings, Southwark Park Road,
Bermondsey, S.E., Engineer, and WILLIAM CHARLES WEBB, of 35, Curlew Street,
Horsleydown, S.E., Wharf Company's Secretary, do hereby declare the nature
of this invention to be as follows:
This invention has reference to an improved construction of driving and brake
mechanism for cycles, which comprises a wheel adapted to be driven by suitable
means from the pedal shaft of the machine and which we will, for purposes of
description, assume to be a sprocket or chain wheel driven by an endless chain
and will hereinafter call the sprocket wheel. This wheel is mounted to be capable
of rotating freely about the axis of the driving wheel of the machine
and has holes formed through it at a suitable distance apart,
these holes having parts of their walls inclined in an annular direc-
tion or merging into grooves those at one side of the wheel having
a reverse direction to those at the other side. The inclined portions con-
stitute grooves of gradually decreasing depth whose general direction is that of
circular arcs struck from the centre of the wheel. On to the hub of the driving
wheel there are screwed or secured two flanged rings. The flange of the one ring.
has its inner face formed at intervals with shallow cavities to accommodate balls.
The flange of the other ring is or may be faced with material that will offer
frictional resistance to rotation, such as a ring of vulcanized fibre or other suit-
able substance. Between the two flanges are mounted the sprocket wheel and a
third ring which is provided with horns or means adapted by contact with a part
of the machine frame or other stop to prevent or arrest rotation of this ring.
That face of this third ring which is next to the sprocket wheel is formed with
shallow cavities adapted to accommodate balls.
The arrangement is such that assuming the sprocket wheel to be driven in a
forward direction, those of its grooves or inclined parts which are next the flange
formed with cavities will by pressure against the interposed balls drive that
flange and consequently the driving wheel of the machine forward-if the rider
stops the pedals, the driving wheel will be free to rotate without the sprocket
wheel; and if the rider back-pedals the brake will be applied, that is to say,
those grooves or inclined parts of the walls of the holes in the sprocket wheel
which are next the thirdly mentioned ring will by pressure against the interposed
balls (which will have passed through the holes in the sprocket wheel) force
the balls against the thirdly mentioned ring which cannot rotate, thus causing
the reverse side of the sprocket wheel to press against one of the flanges fixed on
the driving wheel and causing the other of said flanges to press with its frcitional
surface against the thirdly mentioned ring, at the opposite side thereof to that
at which the sprocket wheel is located.
The details of construction may be more or less varied to suit circumstances.
The thirdly mentioned ring may in some cases be arranged to be capable of

page_text: partial rotation and be provided with means whereby the rider can operate it in
order to apply another or an additional brake.
Other modifications in detail may also be made.
Dated this 1st day of August 1899.
For the Aunlicants
Improvements in Driving and Brake Mechanism for Cycles.
We, WILLIAM HENRY TOMKIES, of 4, Fort Buildings, Southwark Park Road,
Bermondsey, S.E., Engineer, and WILLIAM CHARLES WEBB, of 35, Curlew Street,
Horsleydown, S.E., Wharf Company's Secretary, do hereby declare the nature
of this invention and in what manner the same is to be performed to be particu-
larly described and ascertained in and by the following statement.
This invention has reference to an improved construction of driving and brake
mechanism for cycles as will now be described with reference to the accompany-
ing illustrative drawings wherein Fig. 1 shews in side elevation driving and
brake mechanism according to this invention applied to the rear or driving wheel
of a bicycle. Fig. 2 is a cross section on the line A-A of Fig. 1. Figs. 3, 4
and 5 are side elevations shewing relatively to the machine, the outer side of an
inner ring, the outer side of a sprocket wheel, and the inner side of a brake ring.
Figs. 6, 7, and 8 are developed cross sections on the lines B-B, C-C; and
D-D respectively of Figs. 3, 4 and 5.
On
The improved driving and brake mechanism comprises a wheel a adapted to
be driven by suitable means from the pedal or crank shaft of the machine and
which, for purposes of description, is shown as a sprocket or chain wheel adapted
to be driven by an endless chain and is hereinafter called the sprocket wheel.
This wheel is mounted to be capable of rotating freely about the hub of the driv-
ing wheel c of the machine and has inclined holes d (Figs. 4 and 7) formed
through it at a suitable distance apart, these holes having parts of their walls
inclined in an annular direction and merging into grooves e and f, the grooves e
at one side of the wheel having a reverse direction to those f at the other side.
The inclined portions constitute grooves of gradually descreasing depth, whose
general direction is that of circular arcs struck from the centre of the wheel.
to the hub g of the driving wheel c there are screwed or otherwise secured two
flanged rings h and i. The flange of the inner ringh has its face that is next
the sprocket wheel a formed at intervals with shallow cavities 7, (Figs. 2,3
and 4) arranged in a circular row, to accommodate steel or other hard balls m.
The flange n of the other or outer ring is or may be faced with material that
will offer frictional resistance to rotation, such as a ring o of vulcanized fibre or
other suitable substance. Between the flanges and n of the two rings are
mounted the sprocket wheel a and a third ring p, hereinafter called for distinc-
tion the brake ring, which is provided with means such as horns q adapted by
contact with a part of the machine frames or other stop to prevent or limit
the rotation of this ring. That face of the brake ring which is next to the
sprocket wheel a is formed with shallow cavities t (Figs. 2, 5 and 8), arranged in
a circular row, to accommodate the balls m. The sprocket wheel a can rotate
freely about the hub g between the flanged part of the ring h and the ring i
but cannot move laterally relatively thereto. The brake ring has a small
lateral play between the sprocket wheel a and the flange n of the ring i.

page_text: The cavities and t may be made of semi-spherical or part spherical shape, or,
as shown, as shallow inclined holes having a sharp projecting edge at one end
and of gradually decreasing depth towards the other end.
As will be seen, the arrangement is such that assuming the sprocket wheel a
to be driven in a forward direction, say, in the direction of the arrow (Fig. 1),
those of its grooves or inclined parts, viz. e, which are next the flange k of the
inner ring h will, by pressure against the interposed balls m, drive that flange
and consequently the driving wheel of the machine forward; if the rider stops
the pedals, the driving wheel c will be free to rotate in a forward direction
without the sprocket wheel a the balls m then moving back into the holes d;
and if the rider back-pedals, the brake will be applied, that is to say, those
grooves or inclined parts f of the walls of the holes d in the sprocket wheel a
which are next the brake ring will, by pressure against the interposed balls m
(which will have passed through the holes d in the sprocket wheel a) force the.
balls against one side of the brake ring p which cannot rotate, thus causing the
reverse side of the sprocket wheel to press against the flange of the ring / and
causing the flange n of the other ring to press with its frictional surface o against
the ring at the opposite side thereof to that at which the sprocket wheel is
located. If the brake ring is free to move laterally to a small extent, as it
usually will be, and as it is in the arrangement shown, such ring will be simply
pressed against the frictional surface of the ring i by the balls m when the
sprocket wheel is back pedalled.
The details of construction may be more or less varied to suit circumstances.
For example the grooves e for driving purposes, instead of being of gradually
decreasing depth may be of uniform depth, the balls then acting against the rear
ends of such grooves and the front ends or edges of the cavities in the ring h.
Again Figs. 9, 10, 11 and 12 are similar views to Figs. 2, 3, 4 and 5 respec-
tively showing a modified construction wherein the sprocket wheel a is unpro-
vided with holes such as d (Figs. 2, 4 and 7), so that the pairs of oppositely
extending grooves e and f on its opposite sides are disconnected from each other,
and instead of forming the outer side of the flange kof ring hand the inner side of
the brake ring peach with a series of cavities, each of these parts is formed with a
single annular groove or t' of curved section as shown in Figs. 10 and 12. In this
case two sets of balls m will be required one for use between the wheel a and the
flange of ring and the other for use between the said wheel and the brake
ring p. When the cavities and t (Figs. 2 to 8) are thus omitted, the driving
and braking are effected simply by the jamming of the balls m between one or
other side of the sprocket wheel and the adjacent ring and i, but we prefer to
use the cavities, as in the arrangement shown in Figs. 1 to 8, because the driving
and braking are then effected by the balls without any jamming thereof the balls
being then subjected to a shearing action instead of a compressive action.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed we declare that what
we claim is :-
1. Driving and brake mechanism for cycles wherein, the sprocket or other wheel
to which rotary motion is imparted and a non-rotatable brake ring are arranged
between two flanged rings fixed to the hub of the driving wheel of the cycle,
and there are formed between the said sprocket or other wheel and the flanged
ring on one side thereof, and the said wheel and the brake ring on the other side
thereof oppositely extending circular are shaped grooves in which balls can work
in such manner that when the sprocket or other wheel is rotated in a forward
direction this wheel and the ring next it will become locked together by balls
between them, and on backward rotation of the said wheel the said two parts will
become disconnected and the brake ring will by balls located between it and the
said wheel be forced laterally against the other ring on the hub so as to retard or
arrest the motion of such ring and hub, and when the sprocket or other wheel

page_text: is held stationary, the said balls will be inoperative and the cycle can run forward
independently of the driving and brake mechanism, substantially as described.
2. Driving and brake mechanism for a cycle, comprising two rings fixed on
the hub of the driving wheel of the cycle, a rotatable sprocket or other wheel
adapted to be driven from the pedal shaft of the cycle and a nou rotatable brake
ring arranged between the said two rings, the said sprocket or other wheel being
formed with holes that extend in an inclined direction therethrough and merge into
circular arc-shaped grooves formed at opposite sides of the sprocket wheel, the
grooves at one side of the said wheel extending in an opposite direction to those
at the other side thereof, and balls arranged to work in the said grooves and holes,
the arrangement being such that the balls will pass from one side of the sprocket
wheel to the other and act against one of the said flanged rings or against the
said brake ring, or remain in the holes according as the rider pedals in a forward
direction, or back pedals, or keeps the pedals stationary, substantially as described.
3. Driving and brake mechanism of the kind specified in the preceding claims
wherein the hub ring and the brake ring located on opposite sides of the sprocket
or other wheel are formed on the sides next such wheel and opposite the circular
grooves therein with annular sets of cavities or t into one or other of which the
balls can enter according as the mechanism is being used for driving or braking
purposes, whereby the balls will be subjected to shearing in contradistinction to
crushing stress when in their operative position, substantially as described.
4. Driving and brake mechanism for cycles, constructed arranged and operat-
ing substantially as hereinbefore described with reference to and shewn in Figs. 1
to 8 inclusive, or modified according to Figs. 9 to 12 inclusive of the accompany-
ing drawings.
Dated this 1st day of May 1900.
For the Applicants,
W. LLOYD WISE,
46, Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.