Improvements in and relating to Interchangeable Driving Gear for Cycles.
Year: 1899

page_text: Date of Application, 1st Sept., 1899--Accepted, 7th Oct., 1899
COMPLETE SPECIFICATION.
Improvements in and relating to Interchangeable Driving Gear
for Cycles.
I, CARL PLAGEMANN, of Elsterwerda, in the Empire of Germany, Watch-Maker,
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:-
As known, riding up hill on a bicycle especially on one with a high gear is
very tiring which could easily be altered if it were possible at the beginning of
a hill to throw the ordinary used high gear out of action whilst riding and use
instead chain wheels of equal size and gear.
This invention renders this possible; it relates to a device which by means of
a lever, the high gear can be thrown out of action quickly and easily and at the
same time a chain wheel gear of equal ratio is put into action at will during
riding.
In the annexed drawing Fig. 1 represents a gentleman's bicycle, and Fig. 2 a
lady's bicycle in side view with the device adapted thereto, whilst Fig. 3 shows
the device in plan view, the actuating lever being omitted. In Fig. 4 the lever
is shown in plan and side view.
The arrangement consists of a frame R inserted into the frame of the bicycle;
in this frame R the pedal crank axle A is seated in a suitable manner. In the
middle of this axle A a crown-wheel K is fastened provided on both bearing
parts with teeth and driven by the pedals k. Besides this crown-wheel K there
are two chain-wheels L of equal size, which are arranged loosely and displaceably
on the axle A. On the inner bearing part towards the crown-wheel K each of the
two chain wheels is provided with a toothed rim each conforming with the
respective one of the crown-wheel K. On the other side to the crown-wheel each
of these chain wheels is provided with a prolongation of its nave which each possess
a groove. Into these grooves the forked ends of a fork G which is mounted
movably on the bicycle frame can engage. As soon as the same is moved toward
the right or left it takes the two chain-wheels with it in the respective direction,
whereby the one or the other are respectively put into or thrown out of gear
with the crown-wheel. On the axle H of the hind-wheel are also two chain-
wheels one of which is the ordinary small chain-wheel for the high gear, whilst
the other one is of the same size as its front driving chain-wheel.
As soon as the rider wants to ride with the ordinary high gear, he pushes
the lever towards the left, whereby the left hand driving wheel L, hitherto out
of gear, gears with the crown-wheel K and is consequently put in action by the
cranks K whereby also the bicycle goes faster in consequence of the high gear.
If a hill is met whilst riding, which could be ridden with high gear only with
great difficulty and strength, it is only necessary to push the lever towards the
right whereby the high gear is thrown out of action and the hitherto loose
running chain-wheel L and with it the equally large wheel on the axle H is
put in action. Because there is no gear ratio the rider can go up the hill without
any special difficulty.

page_text: In order that the lever cannot get loose whilst riding and quit its position,
the same is preferably provided with suitable receiving devices.
Having now particularly described and ascertained the nature of my
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
An improved interchangeable driving gear for cycles in which the ordinary
high gear can be put out of action and chain wheels of equal ratio can be put in
action consisting of a frame R arranged on the bicycle frame wherein the pedal
crank-axle A carrying loose and displaceably arranged chain-wheels L L and
a fixed double-sided crown-wheel K; in connection with a fork-like lever G
whose ends are also forked and engage into grooves of the prolonged chain-
wheel-naves and consequently by displacing the lever towards the right or the left
the throwing out of or putting into action of the one or the other chain-wheels of
the double-chain-wheels, is done and consequently an alteration of the driving
gear ratio is effected.
HERBERT HADDAN & Co.,
Agents to Applicant,
18, Buckingham Street, Strand, London.