Improvements in Driving Mechanism for Cycles.
Year: 1894

page_text: Date of Application, 13th Dec., 1894-Accepted, 2nd Feb., 1895
Improvements in Driving Mechanism for Cycles.
We MAX KOHL of 1A Monhaupt Strasse Merchant, and LEOPOLD SERWOTKA
of 13 III Lytzow Strasse, District Surveyor, both of Breslau, 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:-
The present improvements in cycle wheels consists in the arrangement of a.
strong spiral spring inside the wheel frame and in the method of putting this spring
in tension and of utilising this tension.
The accompanying drawing shows the various improvements which we will
proceed to describe.
Within the wheel frame Figs. 3 and 4 inside a chamber is fixed a strong
spiral spring d, fastened to a short rotating spindle c, parallel to the driving axle.
Over the outside turn of this spiral spring d, is pushed a toothed circle f, to which
the outer end of the spring is fastened. If the spindle c, be rotated in the
direction of the arrow and if the same be stopped by a ratchet wheel and
pawl g, h, a rotating movement of the circle f, follows as a development of the
tension, and this movement is transmitted by the gearing i, through the inter-
mediate spindle k, and thence to the driving axle b. In this case the spring tension
assists the rider in the propulsion of the cycle.
In order to maintain the spring in tension, the inventors use the bodily weight
of the rider exerted in a jolting manner owing to irregularities in the level of the
road. The shocks exerted in this manner on the saddle are transmitted through
a spring-supported rod o, to connecting rod sliding in the longitudinal slot t,
of the frame-head p, and thence through the lever v, on the ratchet wheel x,
toothed wheels 1, 2 and 3 and thereby to the spring spindle c.
As the ratchet wheel a, can be easily detached from the connecting rod n, a
tension of the spring may be effected by hand before starting, by rotating the
lever v.
The intermediate spindle k, is connected to the axle 5, of the toothed wheel 2,
by a chain z. On this axle 5, is placed the chain wheel 4, which by the movement
of the lever 7, by the rider, can be put in or out of gear with the wheel 2.
The
By virtue of this arrangement a tension of the spring can be effected also from
the treadle, such tension taking place in particular when descending hills.
resistance exerted in this case by the spring in tension is given out as a counter-
action on the driving spindle b, in the checking or brakeing thereof and of the
wheel driven therefrom.
By fitting the described arrangement to a cycle wheel, the wheel can be used
in two ways.
(1) By withdrawal of the gear i, and after disconnecting the lever v, from the
rod n, as an ordinary cycle wheel. (2) By insertion of the parts i, and v, as a wheel
with spring tension. In the latter case the spring tension may be used (a) to
assist in travelling, in which case the operation of the spring may take place,
(I) By hand through the lever v.
(11) From the seat.
1.
(111) Simultaneously from the seat and treadle.
(b) To assist the brake, in which case the operation of the spring takes place

page_text: The movement from the back wheel takes place after coupling the gearing +,
with the gearing 2. The power of the wheel is then transmitted through the
chain from the axis of the back wheel on to the treadle, partly lost there and the
excess used by means of the parts n, 1, 2, 4, 2, 3, to put the spring in tension.
The transmission does not take place direct from the toothed circle f, of the
spring, that is from the spindle k, on to the driving wheel B, Fig. 1, but is
transmitted thereto with the aid of a set of gearing. The manner of this gearing,
which is shown in Figs. 1 and 2, avoids the friction which takes place in ordinary
toothed wheels and completely dispenses therewith.
By virtue of this transmission, the spring tension may be utilised to produce a
large number of turns of the chain wheel B, and on the other hand to effect the
tension of the spring from the treadle, gradually and with little expense of power,
in spite of the great speed of travelling.
Fig. 1 of the annexed drawing shows a vertical section through the axles of the
wheels, whilst Fig. 2 is a vertical section through X-X of Fig. 1.
One of the two treadle cranks A, A¹, namely A is formed as a double armed
lever, the point of rotation of which lays in the axis of the wheel b, itself. The
gear chain wheel B, is fixed firmly on the tubular axle C, which is itself loosely
fitted on the crank axle. The axle C, is provided with a pin wheel D, and
surrounded by a second axle E, which is firmly connected to the disc G.
disc G, is provided with a shrouded toothed gearing formed from a rotatable
cylinder Z. By means of the rod F; E, and G, are immovably connected to the
wheel-frame.
This
The crank A, is lengthened past the wheel axis and carries here a stud H, on
which a larger toothed wheel M, and a smaller toothed wheel N are rotatively
fitted. These two toothed wheels M, and N, are either firmly fastened together
or are produced from a single piece of metal.
So that the friction may be as little as possible the toothed gear of the wheels M,
and N, is formed of segment shaped projections which engage in the cylinders Z,
of the large wheel G, and also in those which are arranged between the
pin-wheel D.
As these cylinders are rotatable on pins S, only a slight rolling friction takes
place on the rotation of the wheels. The cylinders can be also replaced by ball
bearings.
By the action of the crank the small wheel N,
actuated, also the cylinders
of G, whilst the wheel M, is also put into motion and engages with the pin
wheel D, and rotates the cylinder C, with the chain wheel B. As now G, is
tightly fixed to the wheel frame, the wheel N, is by this means rotated at a high
speed by the revolution of the crank. This speed of rotation is still further
increased by the transmission between M, and D.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
1. An improved spring action and brake apparatus for cycle wheels, distin-
guished by the spiral spring d, which is actuated for giving assistance in travelling
either by the jolts occurring to the_rider_on_the_seat alone,-or-simultaneously with
this, from the back wheel, or also by hand, whilst its tension for assistance in
applying the brake takes place from the back wheel; the transmission from the
seat being effected by means of detachable levers v, ratchet and pawl x, and
toothed wheels 1, 2, 3, and the transmission from the back wheel being. effected
through the driving chain of the cycle wheel, chain wheels m, 1, chains n, z, and
a sliding gear 4, in such manner that after disengaging the lever v, a tension of
the spring d, can be made by hand and after simultaneously withdrawing the
gear i, engaging in the toothed circle fastened to the spiral spring, the wheel can
be used as an ordinary cycle wheel as herein explained and set forth.
2. With a cycle wheel fitted with the arrangement described in Claim 1 an

page_text: apparatus enabling the spring-tension to be used for obtaining a high speed of
rotation and to maintain this in spite of rapid travelling, distinguished by a treadle
crank constructed in the form of a double armed lever to the free arm of which
are fixed two firmly connected cog wheels M, N, of different diameters, the
smaller of which gears into a disc G, fixed firmly to the frame and provided on
the interior with pins or teeth, whilst the other larger wheel M by engaging in
the pin-wheel D, fitted on the crank axle b, effects the rotation of the tubular
axle C, and the driving chain disc B, fixed thereon at increased speed compared
to the movement of the treadle spindle, as herein described and set forth.
Dated this 13th day of December 1894.
S. S. BROMHEAD,
97, Newgate Street, London, E.C., Patent Agent.