Improvements in and connected with Brakes for Cycles and the like.
Year: 1899

page_text: Date of Application, 28th July, 1899-Accepted, 9th Sept., 1899
COMPLETE SPECIFICATION.
Improvements in and connected with Brakes for Cycles and the like.
A communication from abroad by WLADIMER BRANKOVITCH, of 48, Rue de Malte,
Paris, in the French Republic.
I, PHILIP MIDDLETON JUSTICE, of 55 and 56, Chancery Lane, in the County of
Middlesex, Fellow of the Chartered Institute of Patent Agents, 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 an automatic brake for the hub of the driving wheel
of cycles, and is more especially applicable to chain-actuated cycles.
Its characteristic feature consists in producing a braking effect upon back-
pedalling, and in retaining indefinitely the same degree of braking power as
long as the pressure upon the pedals is not modified. In case of breakage of the
chain a device is provided for checking the wheel.
One form of the invention is illustrated in the accompanying drawing, in
which
Fig. 1 is a front elevation of the brake,
Fig. 2 a vertical section, and
Figs. 3, 4 and 5 perspective views, shewing respectively the socket, the pinion
and the spring.
Upon the hub a of the machine a socket b is screwed, the neck of which is
conical. The cylindrical part 63 is provided with recesses, in which balls 63
of a suitable diameter are located. This part if desired may be made solid with
the hub.
The pinion is formed of a toothed rim of rectangular section the interior
diameter of which is equal to the diameter of the cylindrical part 6 of the
socket 6. Helicoidal grooves c¹ of suitable pitch and section permit of the pinion
being screwed on the socket b, the balls serving as the screw threads; so that a
slight forward or backward rotation of the pinion causes a lateral movement of
the latter in one diretcion or the other. The helicoidal grooves c¹ are so arranged
as to drive the pinion-on forward pedalling-toward the neck of the socket
and to engage the cone 6 by a corresponding cone c carried sideways of the
wheel by the vertical part of the rim of the pinion. Upon the other side this
vertical part carries a second cone which, during the braking action, serves
to act upon the cone of a metal spring d, open at d.
This spring has a flat external surface d³. Internally it is provided with a
flange d made conical upon both sides d and d, one of these conical faces d'
being acted on by the cone of the pinion, and the other face de bearing against
the cone e of a washer e firmly connected with the hub by a nut f. The pinion
also carries a tenon which so engages with the open part d' as to keep pinion
and the spring in connection during rotary motion.
When the spring is expanded under the action of the pinion, it exerts a braking
effect upon a flat open ring g, preferably made of bronze and fixed in any suitable
J

page_text: manner to (or adapted to bear against) the frame by means of a screw g¹ so as
to prevent it from turning. This ring g interposed between the spring and the
flange of the toothed rim of the pinion, is centred and maintained in a suitable
position by a thin plate h secured upon the axle of the wheel by a binding nut,
which also prevents dust from settling in the parts of the brake.
The operation is as follows:-
--
On exerting a pressure in a forward direction upon the cranks, the pinion, by
means of its helicoidal grooves takes a lateral movement toward the wheel and
engages by its cone c³, the cone b¹ of the socket, which is firmly connected with
the hub.
On trying to slacken the speed by back pedalling, the difference of speed which
tends to take place between the socket b and the pinion will have the effect of dis-
placing the pinion in the direction away from the wheel; so that the cone c³ of
the pinion will act upon the cone of the spring which, while bearing against
the cone e of the washer by means of its cone d³, will cause an expansion in a
radial direction, and exert a braking effect upon the ring g. This ring expands
in its turn and exerts a braking effect upon the flanged rim of the pinion.
-
An important feature to which importance is attached and which is not met
with in any of the systems employed up to the present time, is the following:-
In brakes worked by back pedalling the whole effort exerted by the foot upon
the pedals, is transmitted, more or less in its entirety to the brake, but it is
always this effort alone which acts whereas in the case of the present arrange-
ment this effort is automatically increased.
As soon as the pinion has acted upon the spring so as to press it against the
open ring the fiction of the latter against this spring will have the effect of
slackening its rotary movement with the pinion. Now, the pinion is carried
round by the hub; if therefore the spring turns less rapidly, it will abut, with
the front edge of its opening, against the tenon of the pinion and will tend to
stop the latter in its rotation, the effect of which will be, to assist automatically
the slackening of the pinion relatively to the hub and, consequently, to increase
the braking effect. The slackening of the pinion and, consequently the difference
of speed between the pinion and the hub are further increased, when after the
spring has acted upon the open ring 9, the latter exerts a braking effect upon the
pinion itself.
If therefore a spring of a suitable power be used the curious
fact occurs that its sole strain or effort upon the pinion for slackening the same
relatively to the hub, is sufficient to impart to the spring a tendency of move-
ment which is strong enough to maintain the spring in an extended position,
and, consequently, to maintain the same degree of braking for an indefinite
period if the feet are simply allowed to follow the pedals in their rotation without
exerting an effort in either a forward or a backward direction. It will also be
observed that the braking is effected upon very large surfaces and uniformly
over the whole periphery.
For the purpose of automatically braking the wheel on a breakage of the
chain the open ring g is provided with a hook g² so arranged that, when the
broken chain drops, there will always be one link that will engage with the
hook. Figs. 1 and 2 represent the broken chain a, one link of which in its de-
scending movement has caught into the hook g², so that the pinion can no longer
turn and will instantaneously effect a blocking of the brake which will be ener-
getic in proportion to the speed of the machine.
Another advantage consists in the fact that the pedals can be caught again,
if they have been accidentally lost in travelling down hill or otherwise. For
this purpose all that is necessary is to wait for their coming round; a simple
knock with the foot against the passing pedal causing a braking effect of a
certain intensity; and as this braking effect is permanent, it is only necessary
to repeat the operation until the movement of the pedals has been slackened
sufficiently to permit of their being caught without difficulty.
It may be remarked that the balls, moving in the screw threads of the pinion,

page_text: are not subject to much wear as they only work to displace the pinion laterally,
and do not support or take up any weight of the brake and are absolutely inde-
pendent thereof.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is: -
1. A brake actuated by back-pedalling, carried on the hub of the driving wheel
of cycles and the like having a pinion rotating in one direction or the other
acording as the pedalling is effected in forward or backward direction, and
adapted to engage during the forward movement, by means of a cone with a
corresponding cone of the hub or of a piece rigidly secured to the hub; and to
expand radially, during back-pedalling, a spring which produces a braking
effect upon a fixed part of the frame substantially as described.
2. In a brake of the kind described in the preceding claim, the arrangement
of pinion acting by a cone upon a corresponding cone of an open spring for
expanding the latter and carrying a tenon or part serving to engage with the
open part of the spring for carrying round the latter when the pinion turns in
a forward direction and to offer a point of support and a point of thrust to the
spring when the latter in its expanded position, exerts a braking effect upon a
fixed open ring, and consequently tends to turn less quickly than the pinion,
substantially as and for the purpose set forth.
3. In a brake of the kind described in the first claim, a conical washer serving
as a support in an axial direction for the open spring substantially as and for the
purpose described.
4. In a brake of the kind described in the first claim, the arrangement of
open ring secured to the frame, which ring, during the braking atcion, is ex-
panded under the action of an open spring, and exerts in its turn a braking
effect upon the chain pinion, substantially as described.
5. An open expansible ring secured to the frame of a cycle or the like and
provided with a hook or part into which a link of the chain will fall if the latter
should break, the object being to stop the chain pinion and thus produce an
automatic braking effect, substantially as described.
6. In a brake of the kind described in the first claim the employment of a
plate for centering the braking ring fixed to the frame, and for preventing dust
from settling in the parts of the brake, substantially as described.
Dated this 28th day of July 1899.
PHILIP M. JUSTICE.