Improvements in Brakes for Bicycles and like Vehicles.
Year: 1896

page_text: Date of Application, 16th Jan., 186
Complete Specification Left, 24th Sept., 1896-Accepted, 21st Nov., 1896
PROVISIONAL SPECIFICATION.
Improvements in Brakes for Bicycles and like Vehicles.
We, HAROLD SIBREE REXWORTHY, of 43 Helix Road, Brixton Hill, in the
County of London, Engineer, and WILLIAM KING, of 43 Chantry Road, Stockwell,
in the County of London, Restaurateur, do hereby declare the nature of this
invention to be as follows:-
This invention has reference to a construction of brake for bicycles and like
vehicles according to which rotation of a sprocket or other wheel forming part of
the driving mechanism of the vehicle is retarded or arrested by causing a friction
device or devices connected to such wheel to make contact more or less close with
a relatively fixed annular friction surface by slight backward motion of the pedal
cranks or of one of them relatively to the sprocket or other wheel or retardation
of the crank or cranks such as to result in the sprocket or other wheel overtaking
the crank or cranks as for example when the rider "back pedals."
In an arrangement of this kind, the friction devices, of which there are two,...
resemble curved bars or links bent to the form of arcs of circles or approximately
so and arranged within an annular frictional surface formed within a cup-like body
or ring secured to a disc or plate fixed to the framing of the vehicle. One end
of each such curved bar is jointed by a pin to the sprocket or other wheel which
is arranged concentrically to the annular friction surface. The other end of each
curved bar is jointed to a pin carried by a plate formed in one with or fixed to
the corresponding pedal crank which is mounted on the boss of the sprocket or
other wheel so as to be capable of turning freely thereon through a small angle.
The joint pins carried by the plates are arranged at opposite sides of the centre
of motion of the crank, and project through slots in the adjacent side of the.
sprocket or other wheel, the arrangement being such that when the crank is
driven in a forward' direction, the joint pins bear against the forward ends of the
slots and drive the sprocket wheels, at which time the curved bars are held out of
contact with the friction ring, but upon back pedalling or resisting the rotary
motion of the crank, produced by the momentum of the machine and rider the.
joint pins connected with the crank will move backward in their slots and cause."
the friction bars to bulge outward and come in frictional contact with the interior.
of the annular friction surface which will then act to retard the motion of the
sprocket wheel and connected parts with more or less force according to the amonnt
of resistance offered to the rotation of the crank. Upon removal of this resistance,
or upon again driving the crank in a forward direction, the curved bars will resume
their original position and the braking action will cease.
One or each of the plates carrying a joint pin, may be connected to the sprocket.
or other wheel by one or more bolts extending or each extending through a slot in the,
adjacent side of the wheel, so that the crank will be held end ways on the boss without
interfering with its ability to partly turn thereon. The pedal crank at the opposite
side of the machine may be fixed upon a cross shaft upon which the sprocket or other
wheel hereinbefore referred to is also fixed.

page_text: COMPLETE SPECIFICATION.
Improvements in Brakes for Bicycles and like Vehicles.
We, HAROLD SIBREE REXWORTHY, of 43 Helix Road, Brixton Hill, in the
County of London, Engineer, and WILLIAM KING, of 43 Chantry Road, Stockwell,
in the County of London, Restaurateur, 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 has reference to the construction as hereinafter described of
brakes for bicycles and like vehicles of the kind in which rotation of a sprocket
or other wheel forming part of the driving mechanism of the vehicle is retarded
or arrested by causing a friction device or devices connected to such wheel to
make contact more or less close with a relatively fixed annular friction surface by
slight backward motion of the pedal cranks, or of one of them, relatively to the
sprocket or other wheel, or retardation of the crank or cranks such as to result
in the sprocket or other wheel overtaking the crank or cranks as for example
when the rider "back pedals."
Referring to the accompanying illustrative drawings Figs. 1 and 2 show 'sectional
views taken in planes at right angles to each other, of apparatus according to this
invention: 1, 1 are two friction devices in the form of curved bars or links bent to
the form of arcs of circles or approximately so and arranged within an annular
frictional surface 2 formed within a ring 3 carried by a disc or plate 4 fixed to the
framing 5 of the vehicle, the said ring and the disc or plate forming a cup-like body.
The frictional surface 2 may conveniently be formed by band or ring of suitable
substance such as leather or copper attached to the inner side of the ring 3. One end
of each bar 1 is jointed by a pin 6 to the sprocket wheel 7 which is fixed upon the
shaft 8 concéntrically to the annular friction surface. The other end of each bar 1 is
jointed to a pin 9 carried by a plate 10 formed in one with, or it may be fixed to, the
corresponding pedal crank which is mounted on the boss 7 of the sprocket
wheel so as to be capable of turning freely thereon through a small angle. The joint
pins 9 carried by the plates 10 project through slots 11 in the adjacent side of the
sprocket wheel, the arrangement being such that, when the crank is driven in a
forward direction, the joint pins hear, as represented, against the forward ends of the
slots and drive the sprocket wheel. At this time the bars 1 are held out of contact
with the friction ring 2, but upon back pedalling or resisting the rotary motion of the
crank produced by the momentum of the machine and rider, the joint pins 9 connected
with the crank will move backward in their slots 11 and cause the bars 1 to bulge
outward and come in frictional contact with the interior of the annular friction
surface 2, which will then act to retard the motion of the sprocket wheel 7 and
connected parts with more or less force according to the amount of resistance offered
to the rotation of the crank. Upon again driving the crank in a forward direction
the bars 1 will resume their original positions and the braking action will cease. The
same thing will happen on mere removal of the resistance to forward rotation of the
crank, if the bars 1 be made as we prefer that they should be of a springy nature and
with a set giving them a tendency to maintain their driving positions. One or each of
the plates 10 is connected to the sprocket wheel by one or more bolts 12 extending or
each extending through a slot 13 in the adjacent side of the wheel, so that the crank
will be held in position endways on the boss without interfering with its ability to
partly turn thereon. The pedal crank at the opposite side of the machine may be
fixed upon the shaft 8.
Figs. 3 and 4 show a modification wherein the cranks are keyed to the axle and
the sprocket wheel is loose on the axle, the parts in other respects being similar in
construction and arrangement and bearing like'reference numbers to those described
with reference to Figs. 1 and 2.

page_text: Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A brake of the kind referred to for bicycles and like vehicles comprising a crank
and a sprocket wheel capable of limited rotary movement relatively to each other, a
fixed annular internal friction surface and friction devices (or a friction device) such
as 1, 1 jointed at one end to the sprocket wheel and at the other to the crank and
adapted to have the outer surfaces (or surface) thereof moved into and out of contact.
with the fixed internal friction surface respectively by the backward movement or
retardation of and by the forward movement of the pedal cranks (or one of them)
relatively to the sprocket wheel.
2 The heroinabove described and illustrated improved brake for bicycles and like.
hicles.
Dated this 22nd day of September 1896.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
For the Applicants,
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.