Improvements in Twin Brakes for Cycles.
Year: 1897

page_text: Date of Application, 9th Dec., 1897
Complete Specification Left, 8th Oct., 1898-Accepted, 9th Dec., 1898
Improvements in Twin Brakes for Cycles.
1, CHRISTOPIDER GEORGE COOPER, of 27, Wellington Park, Clifton, Bristol,
Accountant, do hereby declare the nature of this invention to be as follows:-
My invention relates to improvements in brakes which are made to grip on
rach side of the rims of cycle wheels, and consists in so arranging the shoes which
hold the brake blocks, that they may slide on or in connection with the back
stays of the machine, the pressure being thus applied in a direct line from the
centre to the periphery of the wheel, and the brakes operating with certainty
on an appreciable portion of the rim.
With brakes hitherto made to act on the rim of the wheel, the shoes are hinged
or pivotted, and their first contact with the rim is at the point furthest from the
pivot ar hinge, and their touching surface is gradually increased as the lever is
pressed, this causes the brake pads to wear away very rapidly at one place, and
their action on the rim to be unsatisfactory; by my invention the brakes are made
to slide up and down parallel to the back stays and to present the whole touching
surface of the pad to the rim at the same time, whereby the pressure is distributed;
provision is also made for equalising the pressure, and to adapt it when in use
to any inequalities in the rim.
In carrying this invention into effect, the pressure is obtained from the ordinary
brake lever attached to the head near the handle bar, but instead of being conveyed
to the back stays by cranks and levers attached on one side ouly of the frame,
loop bell crank levers are provided, which are attached to the down tubes, and rods
affixed to the centre front and back of these loops enable the pressure to be con-
veyed centrally throughout, and thus prevent undue strain on the machine, whilst
the two long arms of the levers are conveyed to the back stays in readiness to
netuate the brakes. Brake shoes are made to slide up and down parallel to the
back stays, the shoes may be attached to rods or tubes fitted to slide inside other
tubes fastened to the back stave, or they may have grips fastened to them which
surround the stay tubes and slide up and down, or guides may be provided in
any other suitable manner, attached to, or connected with the stay tubes, in which
the shoes may slide vertically in the manner described.
To ensure accuracy in working, and to adapt the brakes to any inequalities in
the rim, the two lung arms of the levers already described are attached to a fulcrum
on the bar pivotted to the stay tubes above the path of the wheel, the short arm
of this lever is fitted with a knuckle, ball, or universal joint, or to a hook, on
which a compensating plate or slout wire bow is attached in the form of a swivel
plate or frame, the centre being suspended to the hook or joint, and an eye or
hook at either end to support rods which are attached to the brake shoes already
described, the oscillating properties of the plate or bow so suspended will com-
pensate and equalise the action of each brake on either side of the rim.
The levers and connections being positive in their action throughout, a spring
or bent wire of sufficient strength for effectually operating the brake is provided,

page_text: and is so constructed that it will yield or give way under any undue pressure,
and thus prevent damage or accident.
The brake shoes, which act in the manner described, are fitted with grips to
hold the pads or blocks, which may be of leather, rubber, or any other suitable
material, these grips or pads extend on each side of the shoe for any convenient
distance, and are shaped to coincide with the rim of the wheel on which they are
to bear, the outer edge of the grip is extended upwards for a short distance to
form a shield which lies parallel to the rim, thus preventing the grips or pads
from coming into contact with the spokes of the wheel.
Dated this 8th day of December 1897
J. G. WESTLAKE,
Applicant's Agent, 2, John Street, Bristol,
I, CHRISTOPHER GEORGE COOPER, of 27, Wellington Park, Clifton, Bristol,
Accountant, 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:-
My invention relates to improvements in twin brakes which are made to bear
on both sides of the rims of cycle wheels, and cousists in so arranging the brake
shoes and blocks that they may slide on or in connection with the back stays of
the machine, the pressure being applied in a direct line from the centre to the
periphery of the wheel, thus causing the brakes to act with certainty on an appre-
ciable surface of the rims.
With many of the rim brakes at present in use, the shoes are either hinged
or pivoted, and their first contact with the rim is at the point furthest from the
fulcrum, their touching surfaces being gradually increased as the pressure is
applied; this causes the brake pads to wear away rapidly in one place, and their
action on the rim to be unreliable; the object of my invention is to provide means
whereby the brake shoes and pads are inserted in or attached to frames sliding
up and down parallel to and in contact with the back stays, and present the
whole touching surface of the pads to the rims at the same time, whereby the
pressure is distributed; provision is also made for ensuring the compensation of
The two brakes, so that they will act simultaneously on each side of the rim, and
accommodate the pressure to any possible inequalities in the rim.
In putting this invention into operation, the pressure is obtained by means of
the ordinary lever attached to the head of the machine near the handle bar, and
is conveyed to the back stays by cranks and levers, loop or double bell crank
levers being used where the lever, crank, or connecting rod has to pass any inter-
vening down tube, the rods being attached in the centre at the ends of these bell
cranks, enable the power to be conveyed centrally throughout, and thus prevent
undue strain on any one part of the machine. The shoes are fitted on frames
attached to rods or tubes which are made to slide inside auxiliary tubes attached
to the stay tubes, or the frames may have grips attached by which they are held
in position for sliding up and down the tubes, or guides may be provided in other
suitable ways to permit the frames containing the brake shoes to slide parallel
to and in connection with the stay tubes.
My invention includes appliances which are improvements and modifications

page_text: of those described in my Specification No. 26923 of 1896, for which Letters l'atent
have been granted, these enable the improved brake to be operated with greater
efficiency and simplicity.
The means employed for putting my invention into operation will be moro
fully described in connection with the accompanying sheets of drawings, in which
Figure 1 is the front part of a bicycle frame with the rod from the lever on the
handle bar for operating the double bell crank lever; Fig. 2 is the back part of
frame, with connecting rod actuating a twin lever fitted between the back
stay tubes; Fig. 3 is a back view of the stay tubes with a section of the rim and
tyre, and rods depending from the twin lever to actuate the frames inserted in
auxiliary tubes; Fig. 4 is a plan of the double bell crank lever attached to the
front tubes; and Fig. 5 is a plan of the divided connecting rod, the arms of which
actuate the twin lever inserted between the stay tubes; Figs. 6 and 7 are inside
and end views of an alternative frame for containing the shoes, which is attached
by grips to the stay tubes, with wires or rods to serve as guides when the frame
is actuated by rods from the twin lever.
These seven figures on the first sheet of the drawings contain the principal essen-
tial features of the invention, and brakes made in accordance therewith are
specially applicable where the back stays are placed at sufficient distance apart
to allow the twin lever to be attached to lugs placed between them, and where the
rims present a very considerable proportion of horizontal surface on which the
pads may act when pulled in a vertical direction, but as the variety in the distances
apart of the back stays and in the shape of the rims is considerable and frequently
changing, it is necessary to provide modifications which will enable the brake to
be fitted to and used on machines having these variously shaped rims, stay tubes,
aud spaces between them; the nature of these modifications is shown in the suc-
ceeding figures:-Fig. 8 is a transverse view of a frame with the stay tubes almost
meeting at the top, involving a change in the connecting rod and loops to the lever,
in the lever itself, and in the shape of the frame which partly forms and contains
the brake shoes; Fig. 9 is a plan of the metal stamping ready for bending, the
various dotted lines indicating where certain parts are to be bent, some in one
direction, and some in the opposite direction; Fig. 10 shows one side of the frame,
with the parts bent ready for engaging on the stay tube: Fig. 11 shows the outer
side of a stay tube with the clips surrounding it, the projecting parts on the other
side holding the pad, which is secured to the frame by screws passing through
horizontal slots in the plate, (Fig. 12,) through the pad, and bolted on the outside
by nuts as shown; Fig. 13 is a side view of the back of the machine shown in
Fig. 8, with one of the stay tubes partly removed to show the frame in operation
with the shoes and pads ready for action near the rim.
Fig. 14 shows a variation of the divided connecting rod, the arms being united
in consequence of the narrow space between the stays in which they have to
operate, and joined to a rod which actuates a single lever and Fig. 15 is a plan
of a clip attached to the down tube, on which the lever is fulcrumed.
:
Figs. 16, 17, and 18 represent another variation in the shape of the frame which
is necessary when the rim presents a very narrow and wedge shaped surface at
the base, and where a pressure brought against the sides of the rim would cause
a constant outward strain upon the guide stays; to avoid this, the plates which form
the shoes converge rapidly towards each other, and are placed on a frame as shown;
Fig. 16 is a plan of the stamped plates, with dotted lines showing where returns
are to be made at right angles to the face of the plate; Fig. 17 shows two of these
plates with the parts bent outwards, fastened together at the top by a rod working
in a swivel, connected by a rod to the top lever; Fig. 18 shows the frame, con-
sisting of two plates one on each side the stay tubes, working up and down parallel
to them, with shoes and pads ready to operate against a narrow rim.
The same letters indicate similar parts in all the figures.
Referring in the first instance to Figs. 1 to 5, A is the down rod from the lever
on the handle bar to a swivel or ball joint a at the front of a double bell crank

page_text: lever B, which surrounds the front down tube and is fastened thereto by clips
or the like, from the lever B a connecting rod C extends to divided long arms 1)
attached to the upper cranks of a twin lever E fulcrumed on bearings Fattached
to the down stay tubes, the lever being placed between then, the horizontal cranks
of the lever are connected by a cross bar, in the centre of which a ball joint, hook,
or swivel is placed, which supports a curved plate G, to which rods H are attached,
these are connected to shoes fixed on the top of rods or tubes which slide in
auxiliary tubes i fastened to the inner surface of the stay tubes; the tops of the
shoes are fitted with screws and plates to receive pieces of rubber, leather, or other
suitable material J, to serve as pads and bear against the rim of the wheel;
coiled springs are inserted within the tubes and fastened to the shoes and the lower
ends of the principal tubes to keep the brakes away from the rim when not in use;
springs of a similar nature are attached to the various kinds of frames which
support the shoes and pads. Figures 6 and 7 show a variation in the construction
of the frames and their attachment to the stay tubes; plates K are formed with
angle plates at the top and bottom and projecting ears at the sides, against which
clips are fastened, these clips are placed round the tubes and fastened rigidly
thereto by screws or other means; the shoes I' are attached to rods M passing
through holes in the angle plates; the shoes are suspended to and actuated by the
rods as in Figs. 2 and 3, and the springs keep the pads away from the rim
when not in use.
The principal and essential features of the invention are shown in these figures,
where the brake shoes slide up and down in or on frames parallel to the atay tubes
without causing any strain thereon, and also the oscillating property of the curved
plate which works on a pivot or the like, so that it is impossible for any strain
or pressure to be put on the brake on one side of the rim until the one on the
other side receives a corresponding strain, and thus any inequalities in the rim
will not affect the simultaneous action of cach brake.
Figures 8 to 15 indicate a modification of the appliances previously described,
rendered necessary by the very narrow space between the back stays of some
machines, as shown by Fig. 8: the curved plate G is elongated, and placed with
the shors and pads attached thereto around the rim and tyre; the divided arms I)
are united at D', and instead of the twin lever E a single lever E' is used, and a
fulcrum clip is placed and fastened around the down tube instead of the two
fulcrums on the stay tubes, as shown in Fig. 15; a pivot F at the end of the
clip forms a fulcrum on which the single lever E¹ is placed, the upper crank of
this lever is operated by the united long arms 1', and the lower crank is attached
to a rod H', the elongated frame N is substituted for the curved plate G, but is
suspended from the lever by the rod H', bearing in a knuckle or pivot joint, so
that the oscillating property of the plate G already described is transferred to
the elongated frame: this frame is made from a single stamping, as shown in
Fig. 9; the projections O, P, Q, as indicated by dotted lines, being bent in oppo-
site ways as shown in Figs. 10 and 11 to form clips which loosely surround
the stay tubes and also bearings or frames for the brake shoes and pads; the plate
is finally curved as shown, and placed in position around the rim and tyre, and
hung by the rod H' to the lever E', being pivoted as described, the frame will
oscillate freely and cause the brakes to act simultaneously on the rim: the tri-
angular parts P of the plate form projections turned at right angles to the frame,
and the small pieces Q are turned outwards nearly parallel to the frame, with
vertically elongated slots therein, on which the pad J is placed, and then an outer
plate R, (Fig. 12) with horizontally elongated slots, is fastened with screws or
bolts to the turned out plates Q, the plate R and the parts Qforming the shoe
with the pad J placed between them as described.
The elongated slots in the parts Q and the plate R are in reverse directions
to permit accurate adjustments; the horizontal slots in the plate R allow it to
be fitted on shoes or parts of shoes sliding against stay tubes of any width, the

page_text: screws being placed therein and in the pads at such a distance apart that the shoes
will slide up and down without friction; and the vertical slots in the parts Q
are to allow the plate R and the pad attached thereto by screws to be raised and
adjusted to the required distance from the rim when the pad has become worn.
Figs. 16, 17, and 18 show another shaped frame, which is desirable when the
rims are very narrow at the base, and the pressure can only be applied at the sides,
which in the ordinary way would cause a displacement of the stay tubes, this is
avoided by making that part of the frame which forms the shoes at an angle that
will correspond to the curve of the rim on which the pads have to bear; Fig. 10
is a plan of a stamped plate S the projections T thereou being turned at right angles
on the parts shown by dotted lines, the direction of these lines is varied as required,
so that the shoes and pads may converge towards the rim according to the part
on which they are required to operate; two of the plates S are united at the top
by a rod working in a swivel joint, and the four projecting ears T turned
outwards as shown, the pad is placed on the ears and the plate R
(Fig. 12) fastened thereto, the slots in the ears and in the plate admitting a rigid
fastening of the pad in the shoe, while the two plates S are adjusted to the right
distance apart for the frame so formed to slide freely up and down the stay tubes,
and the shoe and pad raised and adjusted when the latter becomes worn.
When the plates so formed and joined are placed on each side the tubes, sus-
pended by the rod H to the lever E and the shoes and pads fitted as shown in
Fig. 18, the frame will oscillate freely and slide up and down the stay tubes in
the manner already described.
For drop frame or ladies' cycles it will be necessary to attach the fulcrum and
lever near the bottom bracket and to cause the brakes to act on the rim in the front
of the wheel in this case the back fork tubes serve as guides, and the various
parts attached to them instead of to the back stay tubes, and the connecting rod
conveyed down the slant tube from the front in such a manner as will be evident
to any cycle engineer.
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. In the construction of twin brakes to operate on the rims of cycles, the
formation of a double bell crauk lever fastened to the front down tube in such a
manner that the pressure on the handle bar lever is conveyed centrally to and from
the front and back of the crank lever all arranged to prevent any unequal strain
on any of the parts, substantially as described and shown.
2. In the construction of twin rim brakes for cycles, suspending the frames
which contain the shoes and pads by a rod or rods, connected at the upper or lower
end to a pivot, swivel, or knuckle joiut, in such a manner that they will oscillate
freely, and thus cause each pad to bear simultaneously on the rim, substantially
as described.
3. In the construction of twin rim brakes for cycles, attaching the brake shoes
and pads to frames that surround or operate in connection with the stay tubes
in such a manner that when the brakes are operated, they will slide to and fro
parallel to the tubes and convey the pressure in a direct line from the hub to
the rim of the wheel, substantially as described and shown.
4. In the arrangement of frames for holding the shoes and pads for cycle brakes
as described, making the necessary parts adjustable, so that they will accommodate
any width of stay tubes, and have their projecting cars turned at such an angle
to the stay tubes as to present the pads in the converging direction required to
bear efficiently ou the rim, according to the various sizes and shapes of rims used,
substantially as described and shown.
5. In the formation of the holes in the plates by which the two parts of the
shoc are bolted together, making these holes elongated in opposite directions,
the horizontal slots being for the adjustment of the frames to the various widths

page_text: of tubes; and the vertical slots for raising, adjusting, and securing the pads at
the right distance from the rim, substantially as described.
6. In the construction of twin rim brakes for cycles, the combination of the
various appliances herein described for the purpose of producing a brake to slide
easily to and fro in connection with the stay tubes, and that will oscillate freely
to distribute the pressure and compensate for any inequalities in the rim, sub-
stantially as and for the purposes herein set forth and illustrated in the accom-
panying drawings.
Dated this 6th day of October 1898
J. G. WESTLAKE,
Applicant's Agent, 2, John Street, Bristol,