Improved Brake and Variable Gear for Cycles and other Vehicles.
Year: 1896

page_text: Date of Application, 27th Mar., 1896
Complete Specification Left, 27th July, 1896-Accepted, 26th Sept., 1896
PROVISIONAL SPECIFICATION.
Improved Brake and Variable Gear for Cycles and other Vehicles.
LEWIS WELLS BROADWELL, Gentleman Clapham Lodge, Clapham Common,
South Side, S.W. FREDERICK OXBORROW, Bootmaker, 160 Manor Street,
Clapham, S.W. do hereby declare the nature of this invention to be as follows:-
To furnish an automatic brake and variable gear for cycles; also, a brake for
motor and other vehicles; and the manner in which it is to be carried out is
substantially as follows:-
We mount the driving-chain-wheel of a cycle upon the crank-shaft thereof
without being affixed to it, but free to revolve upon it. We then affix to the same
crank-shaft two sectional spring disks, one on each side the chain-wheel, and having
disks of leather, or other suitable material between it and them. These spring
disks have diameters nearly equal to that of the chain-wheel and bearing upon it
near its periphery and sufficiently to carry it around with them when the cycle is
being driven upon a level or nearly level road.
To be able to regulate the degree of frictional pressure of the spring disks upon
chain-wheel the right-hand pedal-crank is screwed upon its shaft into contact with
the adjoining spring disk and fastened there by a movable key, so that when
necessary, the key may be withdrawn and the crank given one or more turns
thereby compressing the spring disks and thus increasing their frictional pressure
upon the chain-wheel.
When this device is to be employed as a variable gear; as for example, when
mounting an ascent where a low gear becomes necessary, it develops itself auto-
matically by the slight slipping of the chain-wheel between the spring disks. The
proper degree of this slippage acts as a low-gear, greatly relieves the driver of the
cycle and thus enables him to mount a hill which otherwise he could not do.
When this device is to be employed as an automatic brake it is only necessary to
cease pedaling, and if necessary to back pedal somewhat, when the friction of the
spring disks upon the chain wheel griped between them, will soon bring the vehicle
to rest.
When the device is to be utilised as a brake upon motor or other vehicles we
supply a lever-clutch by means of which the rotation of the spring disks will be
arrested at once and their retarding action upon the chain-wheel will soon arrest
the vehicle.
March 17th 1006
L. W. BROADWELL.
F. OXBORROW.
Improved Brake and Variable Gear for Cycles and other
LEWIS WELLS BROADWELL, Gentleman, of "Clapham Lodge," Clapham
Common S.W. and FREDERICK OXBORROW, Bootmaker, of 160 Manor Street,
Clapham S.W. 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 :-
We mount the driving chain-wheel of a cycle upon the crank shaft thereof

page_text: without being affixed, but, free to revolve upon it. We then affix to this same
crank shaft two dish-shaped friction disks, one on each side of said chain wheel
with leather or other suitable friction material between it and them. These
friction disks, made of any suitable material, have a diameter a little less than that
of the chain-wheel and when properly adjusted together will press upon each side of
it near its periphery with sufficient force to carry it around with them and thus propel
the cycle. To regulate the frictional pressure of these disks upon the driving chain-
wheel, the right hand pedal crank preferably, is screwed upon its shaft into contact
with its adjoining friction disk and fastened there by means of a spring or screw key
in such a manner that the key can be quickly withdrawn, and the crank then be given
one or more turns in either direction, thereby increasing or decreasing the frictional
pressure of the disks upon the driving chain-wheel. This constitutes the automatic
brake, because to inodify or arrest the speed of the cycle, it will only be necessary
to modify or arrest the pedaling, then the friction of the two disks upon the driving
chain-wheel, now moved by momentum only, will soon modify the speed or bring
the vehicle to a standstill. A special advantage attending the employment of this
automatic brake is that in case of the desire or necessity to suddenly dismount when
going at a great speed, the rider needs only to throw his whole weight upon either
pedal when down, which not only brings the automatic brake into action but enables
the driver to safely dismount because of the slippage which then takes place
between the chain wheel and friction disks, which allows the pedal crank to remain
stationary, or nearly so. The automatic brake feature of this invention may be
employed independently of that of the variable gear, if desired. When this device
is to be employed as a variable gear, for example, when climbing a hill, or, resisting
a head wind, or traversing a rough road, and a low gear becomes desirable, it is
automatically developed by means of a regulated degree of slippage which then
takes place between the chain-wheel and the two friction disks, caused by the
increased resistance. This low gear develops itself to a greater or less degree, just
in proportion to the greater or less necessity for it, and is therefore genuinely
automatic in its action, no special act whatever on the part of driver being necessary
to produce it. The normal gear will likewise automatically return so soon as the
level is again reached, and the necessity for a low gear no longer exists.
A properly regulated degree of slippage is indispensable to the development and
operation of the variable gear; whilst too much of it, or none at all, would be
fatal to it. The utilization of this slippage is in fact equivalent in its practical
effect, to reducing the diameter of the driving chain-wheel; which means increase
of leverage and corresponding decrease in labor of driving the cycle. We achieve
the desired regulation of this slippage by the employment of a peculiarly shaped
and peculiarly applied gear spring upon the pedal shaft between a friction disk
and the driving chain-wheel, having a spring ratchet F, see Fig. 5B,-attached
to it and engaging in a notch made to receive in the pedal shaft to compel its
forward movement together with the friction disks, but leaving the pedal shaft
free to move in the reverse direction so as not to impede the brake action. In
case the brake alone is to be employed then we omit the variable gear spring
with its ratchet and apply the latter to the chain-wheel instead; in order to
prevent slippage taking place when climbing a hill or fighting a head wind.
Therefore, when slippage commences the two curved ends of gear spring are
brought into contact with the spokes i of the chain-wheel, or with any other
obstructions affixed to it for the purpose of frequently checking the slippage and
thereby rendering its action and effect intermittent, which is essential to its success
in producing a variable gear. The tension of this gear spring upon and in sur-
mounting these obstructions is regulated by means of the two small set screws S
passing through the adjoining friction disk as shown in drawings (see Fig. 3) or a
spiral spring placed around the pedal shaft between the gear spring and friction
disk may be substituted for the set screws. This gear spring is only brought into
action by the slippage of chain-wheel between the friction disks which it effectually
governs when once properly adjusted.

page_text: In the accompanying drawings:-
Fig. I. represents a dished friction disk in plan, a being the friction surface around
and near its periphery, 6 the dished part, and c the shaft hole.
Fig. 11. is a central sectional view of such a friction disk; similar letters referring
to similar parts in all the figures.
Fig. III. represents a central sectional view of the whole device in combination,
and mounted upon the pedal shaft, in which A represents the chain-wheel; b the
friction disks, B the regulating gear spring; s the small set screws for regulating
pressure of gear spring upon chain-wheel obstructions; his the pedal shaft, C the
pedal crank, and D the screw key.
Fig. IV. is a plan view of the driving chain-wheel A.
Fig. V. is a plan view of the regulating gear spring B with its spring ratchet F.
Fig. VI. represents the curved ends of said gear spring.
Having now particularly described and ascertained the nature of this inven-
tion, and in what manner it is to be carried out we declare that what we
claim is :-
Ist. Mounting the driving chain-wheel of a cycle upon the pedal shaft thereof,
loosely and free to revolve upon it, as and for the purpose herein described and
illustrated by the drawings.
Ind. The two dish-shaped friction disks fixed to the same pedal shaft of a
cycle, one upon each side of the driving chain-wheel, as aud for the purpose above
described and illustrated by the drawings.
IIIrd. The regulating gear spring as above described and illustrated by
Fig. 5B.
IVth. The obstructions i on chain-wheel in combination with regulating gear
spring as described and illustrated.
Vth. The two small set screws for regulating pressure of gear spring upon
obstructions of chain-wheel as above described and illustrated in Fig. 3 of
drawings.
VIth. Utilizing the slippage of chain-wheel between the two friction disks, for
the automatic development of a variable gear and brake for cycles as herein
described and illustrated by the accompanying drawings.
VIIth. The employment of a pedal crank having a spring or screw key
fastening for quickly and conveniently regulating the pressure of the friction disks,
upon the chain-wheel, as and for the purpose herein described and illustrated.
VIIlth. The employment of the ratchet F as in Fig. 5B, or on chain-wheel as
above described."
IXth. The combination and employment of all the parts of this invention,
especially as shown in Fig. III. in the accompanying drawings, as and for the
purposes herein described and illustrated by accompanying drawings.
Xth. The employment of the brake feature of this device for motor carriages
and other vehicles.
L. W. BROADWELL.
F. OXBORROW.