Improvements in Back-pedalling Brakes for Cycles.
Year: 1899

page_text: 0
PROVISIONAL SPECIFICATION.
Improvements in Back-pedalling Brakes for Cycles.
I, CHARLES THOMAS BROCK SANGSTER, General Manager to the Cycle Com-
ponents Manufacturing Company Limited, of Bournbrook, near the City of
Birmingham, do hereby declare the nature of this invention to be as follows:-
This invention relates to back-pedalling brakes for cycles, and particularly
to that class in which a pair of brake shoes are drawn into frictional contact
with the inner periphery of a back wheel rim by means of a stud or projection
on the inside face of a driving sprocket or chain wheel acting upon or actuating
a system of levers connected with the swinging arms which carry the shoes. This
stud, during forward pedalling, has heretofore been arranged to wipe idly past
a yielding arm or member of a lever system arranged within its path and with-
out communicating any movement to the brake shoes, but when a rider back-
pedals, then the said stud is carried round backwards with the chain wheel and
comes against or engages the top edge of the arm, which is depressed and the
brake thereby applied.
According to one part of my present invention, the brake shoes are carried
by a pair of swinging arms pivoted to clips or the like attached to the back forks
of the framing and having jointed to their lower ends respectively the termina-
tion of the branches of a fork or stirrup-shaped frame embracing the wheel.
This frame is suitably connected, such as by means of an adjustable power-
transmission rod, to a rocking arm or lever carried by a sleeve encircling a
spindle, which is supported by an attachment plate, suitably secured by screws
or otherwise to the barrel of the bottom bracket. That end of the said sleeve
coming nearest to the chain wheel is also provided with a hollow arm or box-
like projection, with an open side or edge, presented to the said chain wheel
and located within the said box is a laterally sliding block or yielding catch.
working upon a pair of transversely-disposed guide pins outwardly terminated
by stops or enlargements and encircled by springs bearing against the back of
the said piece and tending to force it outwards against the stops. A part of the
outer edge of the slide is bevelled or inclined upwardly and portions of the top
and bottom of the box enclosing it are gapped or cut away coincidently with the
said incline.
Upon the inner face of the chain wheel or driving sprocket is a stud or pro-
jection preferably having a bevelled edge and so arranged upon the said wheel
as to pass, in every forward revolution, through the gaps of the box arm, and
wipe past the sliding piece, which yields inwardly to admit of the said stud
passing without communicating any movement to the arm and lever, after
which the said slide is forced outwards again into its normal position by the
pressure of the springs behind it. When, however, the chain wheel is caused to
rotate backwardly by a rider back-pedalling, the stud moves with it and strikes
against and is blocked by the projecting top edge of the slide (which may also
be bevelled downwardly to correspond with the bevel of the stud) thus causing

page_text: the box arm to turn downwardly or partially round with the wheel, and carry
with it, the sleeve, whose motion is in turn transmitted through the connecting
rod and fork frame to the levers carrying the brake shoes, which are thereby
applied to the wheel rim.
On forward-pedalling being resumed, the brake is automatically taken off by
means of a spring arranged between a fixed member of the cycle franie and
one of the arms of the lever system. The said arm, or the sleeve carrying it, may
be provided with a suitable stop which comes against a portion of the bottom
bracket and co-operates with the said spring, for retaining the box arni and
yielding slide in their proper positions within the path of the actuating stud.
This brake mechanism is particularly applicable for use in connection with
cycles having "free" driving wheels.
2)
According to another part of my invention, instead of employing a yielding
slide for the wheel stud to wipe past in forward pedalling, but which is engaged
by the said stud or back pedalling and forms a connection between it and the
brake mechanism to be operated, I may arrange upon the chain wheel end of the
sleeve carrying the rocking lever, and within the path of the stud or projection
on the inner face of the said chain wheel, a pivoted wiper arm, with its inner
end jointed to the said sleeve and preferably coming between a pair of knuckles
er ears, with shoulders or edge parts of the arm adapted to come or bear against.
parts of the knuckles which form stops or abutments when the said arm is
depressed by the wheel stud coming upon its top edge when the rider back
pedals, but in the other direction, the arm has a certain freedom of movement
which permits of it yielding or being raised out of the way and without com-
municating any movement to the brake lever, every time the wheel wipes under
and past it in ordinary forward driving. The arm is normally supported or
retained in the path of the stud by means of a light spring, which may be
arranged in several different ways.
For instance, one side of the arm may carry a projecting pin which is encircled
by a rat-trap or coiled spring with its two ends extended into limbs, one of
which is suitably connected to the wiper arm, whilst the other and longer
limb is extended towards the joint end of the said arm and bears upon a flat or
other abutment formed either upon or by the edge of one of the joint ears
or knuckles, or upon the side of it or elsewhere.
Or a similar double-limbed spring may be carried either upon an extension of
the wiper-arm pivot, or upon a separate pin projecting from one of the joint
ears, and one limb of it may take through a stud on the side of the said arir or
be otherwise connected with it, whilst the other may take into a small hole in
the sleeve to which the arm is jointed, or into one of the knuckles, or any other
convenient part which is fixed relative to the wiper arm.
Instead of such a spring as described, I may use a small spiral spring one
end of which is secured to the wiper arm and the other end to a knuckle, or to
the sleeve.
In every case these springs are double acting and serve to retain the wiper
arm to its normal position either after it has been lifted by the stud wiping
under it, or depressed by the stud coming against its top edge for operating the
brake. The usual take-off spring for relieving the pressure of the brake upon
the rim, is in every case, provided between the rocking arm fixed on or to the
sleeve and a part of the cycle framing.

page_text: Improvements in Back-pedalling Brakes for Cycles.
I, CHARLES THOMAS BROCK SANGSTER, General Manager to the Cycle Com-
ponents Manufacturing Company Limited, of Bournbrook, near the City of
Birmingham, 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 back-pedalling brakes for cycles and particularly of
that class in which a pair of brake shoes are drawn into frictional contact with
the inner periphery of a back-wheel rim by means of a stud or projection on
the inside face of a driving sprocket or chain wheel acting upon or actuating a
system of levers connected with the swinging arms which carry the shoes. This
stud during forward pedalling, has heretofore been arranged to wipe idly past a
yielding arm or member of the lever system arranged within its path, without
communicating any movement to the brake shoes, but when a rider back-pedals,
then the said stud is carried round backwards with the chain wheel and comes
against or engages the top edge of the arm, which is depressed and the brake
thereby applied.
According to one part of my present invention, I propose to communicate the
movement of the backwardly rotating chain wheel to the lever mechanism of
the brake through the medium of a special form of catch or yielding slide.
Figure 1 of the accompanying drawings represents a prespective view of back-
pedalling brake mechanism fitted with my improved device for communicating
back pedalling motion to the brake, but which is inoperative during forward
pedalling.
Figure 2 represents a side elevation of the said brake mechanism, upon an
enlarged scale.
Figure 3 is a front elevation of a portion of the improved mechanism, with
the casing or hollow arm which contains the spring catch device broken away to
show the internal arrangement..
Figure 4 represents an underside plan of the brake, with the catch in horizontal
section.
The same letters of reference indicate corresponding parts in the said Figures 1
to 4.
In the brake mechanism shown in the said figures, the brake shoes, are
carried by a pair of swinging arms a¹, pivoted to clips a², attached to the back
forks b, of the cycle framing and having respectively jointed the terminations of
the branches of a fork or stirrup-shaped frame c embracing the wheel de
and connected by means of an adjustable power-transmission rod to an arm or
lever e carried by one end of a hollow rock shaft or sleeve e, turning about a
spindle e², supported by an attachment plate e secured to the barrel of the
bottom bracket. The other end of the said rock sleeve, adjacent to the chain
wheelf, is provided with a hollow arm or box-like projection g with an open
side g¹ presented to the said chain wheel and located within the casing thus
formed is a laterally sliding block or inwardly yielding catch h, working upon
a pair of transversely-disposed guide pins h', outwardly terminated by stops or
enlargements h². Springs i bear against the back of the said block h, and tend
to force it outwards against the stops h². A part of the outer edge of the slide
is bevelled or inclined upwardly at h³ and portions of the edges of the box
enclosing it are gapped or cut away at g², g³ coincidently with the said incline.
Upon the inner face of the chain wheel or driving sprocket is a stud or pro-

page_text: jection preferably having a bevelled edge and so arranged upon the said
wheel as to pass, in every forward revolution, through the gaps 2, 3, of the box
arm and wipe past the sliding piece, which yields inwardly to admit of the said
stud passing without communicating any movement to the arm and lever, after
which the said slide is forced outwards again into its normal position by the
pressure of the springs behind it. When, however the chain wheel is caused to
rotate backwardly by a rider back-pedalling, the stud moves with it and strikes
against and is blocked by the top edge of the slide (which may also be bevelled
downwardly to correspond with the bevel of the stud) thus causing the box arm
to turn downwards or partially round with the wheel, a corresponding movement
is transmitted through the rock sleeve to the lever at the other end whose
motion is in turn transmitted through the connecting rod and fork frame to
the levers carrying the brake shoes, which are thereby applied to the wheel
rim.
On forward-pedalling being resumed, the brake is automatically taken off by
means of a spring arranged between a fixed member of the cycle frame and
one of the arms e¹ of the lever system, which is also provided with a suitable
stop, designed to come against a portion of the bottom bracket and co-operate
with the said spring for retaining the box arm and yielding slide or catch in
their proper positions within the path of the actuating stud.
According to another form of my invention, (which is represented in side
elevation in Figure 5 and in back elevation in Figure 6) instead of employing
a yielding slide for the wheel stud to wipe past in forward pedalling, but be
engaged by the said stud on back-pedalling for forming a connection between it
and the brake mechanism to be operated, I may arrange upon the chain wheel
end of the sleeve e carrying the rocking lever e and within the path of the stud
or projection, on the inner face of the said chain wheel f, a pivoted wiper
arm g with its inner end jointed at g', to the said sleeve and preferably coming
between a pair of knuckles or ears, with a shoulder 3 on the forward edge
of the said arm adapted to come or bear against parts of the knuckles which
form stops or abutments when the said arm is depressed by the wheel stud i
coming upon its rearward edge when the rider back pedals, but in the other
direction, the arm has a certain freedom of movement which permits of it
yielding or being raised out of the way and without communicating any move-
ment to the brake lever, every time the wheel wipes under and past it in ordinary
forward driving. The arm is normally supported retained or kept suspended
in the proper position within the path of the stud, and returned to its normal
position every time after the said stud has wiped past it, by means of a light
spring, which may be arranged in several different ways.
Thus in the said Figures 5 and 6, a double-limbed coiled or rat-trap spring k,
is carried upon a pin 2, which may either be an extension of the wiper-arm
pivot, or a separate pin projecting from one of the joint ears, and one limb
of it may take through a stud, on the side of the said arm or be otherwise
connected with it, whilst the other limb, may take into a small hole in the
sleeve to which the arm is jointed, or into one of the knuckles, or any other
convenient part which is fixed relative to the wiper arm.
Figure 7 represents a back elevation and Figure S a side view of a modified
form of spring for keeping the wiper arm in suspension and returning it to its
normal position after it has yielded to admit of the passage of the actuating
stud.
In this arrangement, the inner side of the wiper arm carries a projecting
pin which is encircled by a rat-trap or coiled spring with its two ends
extended into limbs 2, 3, the former of which is connected to the wiper arm by
engaging within a hole g³ formed in it whilst the other and longer limb is
extended towards the joint end of the said arm and bears upon a flat or other
abutment, formed either upon or by the edge of one of the joint ears or
knuckles, or upon the side of it or elsewhere.

page_text: Instead of such a spring as described, I may use a small spiral spring k such
as represented in Figure 9, one end of which is secured to the wiper arm g
whilst the other end is connected either to a hook g³, carried by a joint knuckle,
or to the rock sleeve or shaft of the brake mechanism.
In all these arrangements, the springs are double acting and serve to return
the wiper arm to its normal position either after it has been lifted by the stud
wiping under it, or depressed by the stud coming against its top edge for operat-
ing the brake, but as a further modification, I may employ a pair of re-acting
springs acting in opposite directions to act upon the wiper arm in the manner
as described where double-acting springs are used. The usual take-off spring
for relieving the pressure of the brake upon the rim, is in every case, provided
between the rocking arm fixed on or to the sleeve and a part of the cycle framing.
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:
First In back-pedalling cycle brake mechanism actuated by means of a
stud or equivalent projection on the face of the chain wheel, the employment of
a laterally sliding spring block or inwardly yielding catch, located with a box
arm constituting one of the lever members of the mechanism and adapted to
yield inwards for the wheel stud to wipe past it inoperatively during forward
pedalling, but to be engaged by the said stud, when the rider back pedals, for
establishing connection between the said chain wheel and the brake mechanism
to be operated, substantially as herein described and also as set forth in Figures 1
to 4.
Secondly-In back-pedalling cycle brake mechanism operated by means of a
stud or equivalent projection on the face of the chain wheel acting upon a
jointed wiper arm or member of the lever mechanism; the employment in
connection with the said wiper arm, of a spring or springs, or a double-acting
spring, arranged in either of the several ways herein described and also as
set forth in Figures 5, 6, 7, 8 and 9, by the re-action or rebound of which, the
wiper arm is kept in its proper position, or held in suspension within the path
of the operating stud, and is returned to its normal position after yielding to,
or being acted upon, by the said stud.