A New or Improved Rim Brake for Cycles.
Year: 1899

page_text: Date of Application, 2nd Aug., 1899
Complete Specification Left, 15th Nov., 1899-Accepted, 23rd Dec., 1899
TRUVIDIONAL SPECIFICATION.
A New or Improved Rim Brake for Cycles.
FREDERICK WILLIAM BYWATER, Cycle Engineer, Carrs Mill Cycle Works,
Bradford Road, Birstall, nr. Leeds, do hereby declare the nature of this inven-
tion to be as follows:-
This invention is in relation to a new or improved rim brake for cycles and
consists of attaching to the front or back forks a grip clutch so arranged as to
grip the rim of the wheel, the said grip is worked upon suitable stands on the said
1orks and action is given to the said grip by a connection from the handle-bar
by a flexible shaft to work a suitable worn wheel & cam, the said grip clutch
consists of two levers opened out at the top by means of a cam and grip the
rim at the opposite ends of the levers, the ends of levers is filled in with com-
position so as not to damage the rims.
Dated thig 31st day of August 1800
I, FREDERICK WILLIAM BYWATER, of Corrs Mills Cycle Works, Bradford Road,
Birstall, near Leeds, in the County of York, Cycle Manufacturer and Repairer,
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:-
This invention relates to a new or improved rim brake for bicycle and like
wheels, and comprises a grip clutch attached to the front forks or rear stays of
the machine frame and arranged to grip both sides of the rim of the wheel,
the said grip clutch being specially constructed to be actuated by cam or cam
block or wedge deriving motion from a twisting handle on the handle bar; or
from the ordinary brake lever and plunger; or, in the case of machines fitted
with free wheels, from the reverse or backward movement of the cranks when
their forward motion is suspended.
In the accompanying drawings forming a part of this specification,
Fig. 1 is front elevation, partly in section, of so much of a bicycle as is
essential to shew the application of my improved rim brake and the method of
actuating the sliding cam block or wedge from a twisting handle on the handle
bar;
Fig. 2 is elevation and Fig. 3 plan view of a modified cam adapted to act
rotatively on the grip brake:

page_text: Fig. 4 is front elevation, similar to Fig. 1, shewing the method of actuating
the sliding cam block or wedge by the ordinary brake lever and plunger;
Fig. 5 is side elevation of Fig. 4;
Fig. 6 is side elevation and Fig. 7 plan view of my improved rim brake as
applied to the rear wheel and actuated by the backward movement of the pedal
cranks;
Fig. 8 is enlarged front elevation of the brake shewing a modification of the
actuating cam block or wedge.
The same letters of reference denote corresponding parts in all the figures.
Referring firstly to Fig. 1, letter a represents a pair of brake shoes adapted
to act on each side of the rim of the wheel and carried by or formed on the
lower ends of levers c centred or pivotted on studs & secured to the front forks e
of the machine. The upper ends of levers c are bent or shaped to converge
towards each other from their extremities for a suitable portion of their length
in the form of the letter V, the inner or opposing sides of such portions of the
levers being mitred or bevelled on both edges to enter and fit corresponding
grooves or ways cut or formed in the sides of a cam block or wedge f placed
between said converging portions of the levers. The cam block or wedge has
a screw threaded opening formed centrally through same in and through which
is adapted to work a coarse screw g on the lower end of the rod or spindle h
supported at opposite ends in bearings i and j. On the upper end of the spindle
is a worm wheel into which gears a worm fast on a flexible shaft m connected
to any ordinary form of twisting handle on the handle bar ", such twisting
handle being well known and forming no part of this invention.
To apply the brake, the rider actuates the twisting handle to turn or rotate
the flexible shaft m which through worm and worm wheel gives rotary
motion in one direction to the spindle or rod and consequently to the screw g
thereon, whereby the cam block or wedge f is caused to work downward on
said screw, thus forcing the upper ends of the levers c outwardly and bringing
the lower ends thereof nearer to each other, by which means the brake shoes
are forced tightly against the two sides of the rim b, the brake power applied
being under the control of the rider and varying with the extent of downward
movement of the cam block or wedge f. The brake is applied progressively
and acts firmly and equally throughout, while liability to slip round the rim and
to strain or otherwise damage the rim is minimised.
The brake shoes a are preferably formed to receive blocks o of leather, com-
position, or the like, to prevent injury to the surface of the rim.
The reverse movement of the twisting handle turns the spindle h and screw g,
in the opposite direction to that previously specified and raises the cam block
or wedge to its normal position. Flat springs p pressing against the levers c,
above the fulcra d, or a spiral spring connected at each end to said levers,
ensure the return of the parts to their normal positions and remove the brake
on the cam block or wedge f being elevated again after applying the brake.
In lieu of a sliding cam block or wedge, I may secure to the rod, or spindle, h
in a suitable position between the upper converging ends of the levers c, an
oval or equivalent shaped cam f (see Figs. 2 and 3) which normally presents
its shorter radii to the levers c, but, when the rod or spindle h is turned by
the action of the twisting handle as before described, the longer radii of said
cam are brought progressively to bear on the lever c which are therefore forced
away from each other and bring the brake shoes a to bear on the rim b, the
action being approximately the same as described with reference to Fig. 1 but
the cam acting rotatively with the rod or spindle instead of sliding vertically
thereon.
In Figs. 4 and 5, I shew the method of actuating my improved rim brake
by the ordinary brake lever and plunger of the tyre brake. The cam block or
wedge is secured in a suitable position on the plunger h to engage with the
opposing sides of the bent upper ends of the levers c. The pull by hand on the

page_text: brake lever causes the plunger h to be depressed, as usual, thus forcing the
wedge downward and actuating the levers c to apply the brake as before
described.
The plunger may have applied to its lower end, or may retain, the ordinary
tyre brake shoe r thus forming a combined rim and tyre brake as shewn at
Fig. 4.
At Figs. Gand 1 shew the application of my improved rim brake to the rear
or driving wheel of a bicycle. The cam block or wedge f is secured to a sliding
plate or rod h supported in bearings in a brackets attached to the rear stays t.
When the machine is fitted with a free wheel, the said plate or rod h is coupled
by a link or connecting rod u to a clutch rim fitting on a clutch of any ordinary
kind on the crank shaft. This clutch rim, as is well known, remains stationary
when the machine is being propelled but, when the rider ceases to rotate the
cranks in a forward direction and the machine runs free, any backward move-
ment of the pedal cranks causes the rim to be engaged with the clutch and
turn therewith and, consequently, through connecting rod and sliding plate h.
the wedge f is forced forward between the converging ends of the levers c and
opens them out, thus bringing the brake shoes into engagement with each
side of the rim b. When the machine is not provided with a free wheel, the
sliding plate h can be actuated by a wire cord from the brake lever or twisting
handle on the handle bar.
In Fig. 8 I shew a modification consisting of a strap or block f having
openings therethrough, into which enter the upper ends of the levers c. This
block is secured to the plunger h or actuating rod and, when forced forward
over the converging ends of the levers c, it gradually moves them apart and
applies the brake in the same manner as in the case of the cam block or wedge
of which it forms an equivalent.
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 rim brake comprising a pair of levers c carrying at one end brake shoes a
and having their opposite ends bent or shaped to converge toward each other
from the extremities for a suitable distance, and a cam or cam block or wedge
acting rotatively or by sliding motion between the converging ends of the said
levers to expand them and close the opposite ends or brake shoes upon the sides
of the rim of the wheel, substantially as herein set forth and shewn on the
drawings.
(2) In a rim brake the combination of levers c carrying brake shoes a, cam
or cam block or wedge or its equivalent for actuating said levers to close the
brake shoes upon the sides of the rim under pressure and the means for giving
rotary or sliding motion to the cam or cam block or wedge to actuate the levers c
substantially as herein described with reference to the several figures on the
drawings.
"
(3) The combination of grip levers c, cam block or wedge f, plunger h, and
tyre brake shoe r, comprising the herein described combined rim and tyre brake,
substantially as set forth and shewn at Fig. 4.
Tafod this 10th day of November 1899
TASKER & CROSSLEY,
Patent Agents, Huddersfield, Agents for Applicant.