Improvements in and relating to Driving and Brake Mechanism for Cycles.
Year: 1898

page_text: Date of Application, 27th Apr., 1898-Accepted, 9th July, 1898
COMPLETE SPECIFICATION.
Improvements in and relating to Driving and Brake Mechanism
for Cycles.
We, JAMES BORCHERDING, Engineer, of 596, Buntenthorsteinweg, and WILHELM
FINCKE, Cycle Manufacturer, of 2, Ausser der Schleifmuhle, both of Bremen, in the
Empire of Germany, 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 driving mechanism for cycles, which enables the rider
when travelling down gradients of utilising the momentum of the cycle and of
resting the feet upon the pedals, and also, in the case of danger or of too great
a velocity of the cycle, of effecting a certain breaking action by pack pedalling.
It has already been attempted at different times to render the hind wheel loose
or freely revolving when travelling down gradients by the action of a pawl or single
ratchet mechanism with screws, springs or the like. But these devices have not
come into practical use in consequence of the noise and great friction produced,
and also in consequence of the insecure throwing into gear of the ratchet mechanism.
Now the essential part of the present invention consists of the ratchet mechanism
which is characterised by the fact that between the box or case-like part of a
loosely mounted chain wheel, and a disc or pulley fixed to the revolving hub or
axle, there are arranged arresting bodies (which are advantageously constituted
by balls or rollers) which jam themselves, when the chain wheel revolves in one
direction, between the edge (which is formed with inclined surfaces) of the disc,
and the chain wheel but which when the chain wheel is at rest or when it is
rotating in the opposite direction, assume such a position that they can no longer
jam, and therefore allow the chain wheel to revolve freely.
This invention is illustrated in the accompanying drawings in which Figure 1
is a side elevation of the hub of the hind wheel, shewing the ratchet mechanism
in section. Figure 2 is an elevation of the ratchet mechanism proper partly in
section, in the condition in which the jamming effect is not taking place.
Figure 3 is a similar view showing the jamming effect that has taken place.
Figure 4 shows another form of construction of the ratchet mechanism. Figure 5
shews the hind wheel hub brake, which is connected with the ratchet mechanism,
in the state of rest. Figure 6 shows the same, during the braking operation,
and Figure 7 is a plan of the combined brake ratchet.
The chain wheel b is mounted on one side of the hind wheel hub a, so as to be
capable of revolving loosely on the axle h, and its box or case-like part c on the
right and left hand sides respectively takes over discs d and e, which are formed
with teeth on their edges. Between the box or case-like edge c of the chain
wheel b, and the edge of the disc d (Figure 2), there are provided jamming
bodies which are preferably constituted by rollers, and which are either situated
at the deepest points of the toothed or wedge-like serrated edges of the discs, and
thus allow of an independent rotation of the chain wheel b, or they jam themselves
between the edge cand the higher situated parts of the disc d, and then couple
the chain wheel with the hub.
If the cycle is driven in the proper way in the forward direction and the chain

page_text: wheel 6 moves in the direction of the arrow shown in Figure 2, the jamming bodies f
act in such a manner that they drive the hub a round, through the medium of
the disc d. If now the cyclist wishes to rest, for example when travelling down
a gradient, he simply leaves his feet on the pedals, but without pressing upon the
same, whereupon the jamming bodies f drop into the deeper grooved portions of
the disc and uncouple the chain wheel b, which is then driven steadily further,
so that a good utilization of the momentum is effected. In order also to provide
an effective and conveniently operated brake, together with the new cycle driving
mechanism, the arrangement or procedure is as follows:
-
The ratchet disc e (Figures 1 and 3) is formed with inclined tooth grooves which
are cut in opposite directions, to those of the disc d, and then with the help of
the jamming bodies g, the disc e can be coupled with the box or case-like part c,
of the chain wheel b, when there is no coupling effected between c and d. If now,
the chain wheel 6 be rotated backwards, by back pedalling, the disc e is locked
and moved backwards, and a rod n which is jointed to the pin o of the disc e is
caused by means of a lever m pivotted at m and of the bar 1, and also of the
joint link k, to press a brake band i, around the hub, a, and thus to produce a
braking action. The braking bodies g and the disc e are closed in by a cover
plate g in which there is also provided a guide groove p, Figure 2. In this guide
groove when the disc e is shifted, there moves a screw r, so as to limit the extent
of movement of the disc e. Either the hub a or the brake band i is lined or coated
with leather or other suitable material for the purpose of protecting the respective
brake parts as much as possible.
Figure 4 shows ratchet bodies f¹ which have a wedge-like shape and which are
moved forwards by means of springs f.
It may also be stated that the driving mechanism can be employed independently
of the brake in which case it will be of advantage that the chain wheel which is
directly connected to the pedal crank should be mounted loose, and be provided
with the ratchet mechanism.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is―
(1) Driving mechanism for cycles, characterised by the fact that one chain
wheel is arranged loose, and encloses with its box or case-like part c, jamming
bodies balls or rollers, which when the chain wheel rotates in one direction, get
jammed between the inner surface of the case or box part and the inclined surfaces
which are formed on the edge of a disc that is fixed to the axle or hub to be rotated,
whilst when the chain wheel is at rest, or revolves in the opposite direction, the
said bodies or balls drop into the deeper places of the edge of the disc and then
allow the axle or wheel hub to run independently of the loose chain wheel.
(2) Mechanism for driving cycles in accordance with Claim 1, characterised by
the fact that the chain wheel b which is mounted so as to revolve loose on the axle
of the hind wheel, jams or locks when it moves forwards, through the medium of
braking bodies (rollers or balls) the grooved disc d which is arranged on the hub
of the hind wheel, whilst when the said chain wheel moves backwards it releases
this disc, but locks the disc e which is connected by means of rods with a band
brake that embraces the hub of the hind wheel.
(3) The improved mechanism for driving cycles, substantially as hereinbefore
described and shown.
TL 031 1
Dated this 27th day of April 1898.
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M. I. Mech. E.,
Consulting Engineer, & Patent Agent, 70, Chancery Lane, London, W.C.,
Associate Agent.