Improvements in Driving Gear for Velocipedes and other Road Vehicles.
Year: 1897

page_text: Date of Application, 1st June, 1897
Complete Specification Left, 12th Feb., 1898-Accepted, 19th Mar., 1898
PROVISIONAL SPECIFICATION.
Improvements in Driving Gear for Velocipedes and other Road
Vehicles.
I, SALOMON FRANK, of 21, Friedberger Landstrasse, Frankfort-on-the-Main,
in the Empire of Germany, Mechanical Engineer, do hereby declare the nature
of this invention to be as follows:-
-
The object of this invention is to provide a chain driving gear for velocipedes
and other road vehicles which can be rapidly changed, to vary the speed of motion
as required by circumstances. According to this invention the chain is con-
ducted over two rollers situated outside the gearing proper and made adjustable
in a vertical direction; so that by them the chain can be caused to operate either
of two or more chain-wheels of different dimensions.
The accompanying diagrams illustrate arrangements by which the invention
can be carried into effect but I do not limit myself to the precise arrangements
illustrated.
Referring first to Figures 1 and 2 on the crank-shaft of a velocipede for example
are mounted two chain-wheels a and b of different diameters; the pinion e being
fast on the rear-wheel axle, upon which there is also mounted so that it can be
turned thereon a lever, of such length that it extends beyond the chain wheels
secured on the crank shaft. The front part of this lever carries two rollers d d³,
over which the chain also passes. The rollers d and d¹ are so arranged that the
upper portion of the chain can be engaged with the larger wheel b while the lower
portion of the chain can be engaged with the smaller wheel a according to
whether a high or low speed is to be transmitted. By operating any suitable con-
trivance connected with the aforesaid lever the chain can be thrown into gear with
either wheel (a or b) quickly and reliably, even whilst the machine is in motion.
In Figure 1, the chain f is shewn as engaging with the smaller wheel a, while
in Figure 2 it is shewn as engaging with the larger wheel b; the said chain f,
in either case, constantly moving over the rollers d d¹. The gear in the position
illustrated in Figure 1 is for use in ascending gradients, or in riding against the
wind, while the gear in the position illustrated in Figure 2 is for use on a level
road.
Another arrangement of the improved driving gear is illustrated in Figures
and 4 wherein two, three or more wheels such as bb1b of different diameters are
mounted on the crank-axle. In order to vary the speed, or to alter the disposition
of the driving gear to suit the nature of the ground or other circumstances the
chain is brought into engagement with the desired wheel in the set by adjusting
the lever carrying the rollers d and moving the wheels or the lever laterally.
This also may be effected while the machine is in motion.
Here,
A further modification of the arrangement is illustrated in Figure 5.
also. a set of wheels b, b1, b.
is mounted on the crank axle: but

page_text: one roller e only, is used in this case it being situated in front of the
wheels b, 61, 63. ; the chain f being carried over the roller e from the wheel c,
and being operated by either of the gear wheels b, 61, 63, according to the adjustment
of the wheel e. In this arrangement the friction is materially reduced, a fact
which becomes particularly noticeable in ascending slopes or riding against the
wind.
The adjustment of the rollers may be effected by any suitable means such as by
pivotting the lever, carrying the said rollers, to the rear-wheel axle and guiding
it in a slide-way upon a crank axle, so that it may be adjusted and fixed according
to requirements.
The arrangement may be still further modified by placing the rollers behind
the gear-wheel or pinion on the rear-wheel axle instead of in front; and the set
of gear wheels may be mounted upon the rear-wheel axle, so as to distribute the
load more evenly, and not to interfere with the cyclist's movements in operating
the pedals.
Note this 1at dov of Tuna 1907
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Velocipedes and other Road
Vehicles:
I, SALOMON FRANK, of 21, Friedberger Landstrasse, Frankfort-on-the-Main,
in the Empire of Germany, Mechanical Engineer, do hereby declare the nature
of this invention and in what manner the same is to be performed to be particu-
larly described and ascertained in and by the following statement:
-
The object of this invention is to provide a chain driving gear for velocipedes
and other road vehicles which can be rapidly changed to vary the speed of motion
as required by circumstances.
According to this invention the chain is conducted over two rollers, situated
outside the gearing proper, and made adjustable in a vertical direction; so that
by them the chain can be caused to operate either of two, or more, chain wheels
of different dimensions.
The diagrams accompanying my Provisional Specification illustrate arrange-
ments by which the invention can be carried into effect but I do not limit myself
to the precise arrangements illustrated. Referring first to Figures 1 and 2 on
the crank shaft of a velocipede, for example, are mounted two chain wheels a
and of different diameters, the pinion c being fast on the rear wheel axle, upon
which there is also mounted so that it can be turned thereon, a lever, of such
length that it extends beyond the chain wheels secured on the crank shaft. The
front part of this lever carries two rollers d d over which the chain also passes.
The rollers and are so arranged that the upper portion of the chain can be
engaged with the larger wheel b while the lower portion of the chain can be
engaged with the smaller wheel a according to whether a high, or low, speed is
to be transmitted. By operating any suitable contrivance connected with the
aforesaid lever the chain can be thrown into gear with either wheel (a or b)
quickly and reliably even whilst the machine is in motion.
In Figure 1, the chain f is shewn as engaging with the smaller
while in Figure 2 it is shewn as engaging with the larger
the said chain f in either case constantly moving over the
wheel a
wheel b;

page_text: rollers dd. The gear in the position illustrated in Figure 1 is for use in ascend-
ing gradients, or in riding against the wind, while the gear in the position illus-
trated in Figure 2 is for use on a level road.
Another arrangement of the improved driving gear is illustrated in Figures 3
and 4, wherein two, three, or more wheels such as bb1b of different diameters
are mounted on the crank axle. In order to vary the speed, or to alter the dis-.
position of the driving gear to suit the nature of the ground, or other circum-
stances the chain is brought into engagement with the desired wheel in the set
by adjusting the lever carrying the rollers dd and moving the wheels on the
lever laterally. This also may be effected while the machine is in motion.
A further modification of the arrangement is illustrated in Figure 5. Here,
also, a set of wheels bb12.
is mounted on the crank axle but one roller e
only is used in this case it being situated in front of the wheels bb162...
the chain f being carried over the roller e from the wheel c and being operated
by either of the gear wheels bb162... according to the adjustment of the wheel e.
In this arrangement the friction is materially reduced, a fact which becomes
particularly noticeable in ascending slopes or riding against the wind.
The adjustment of the rollers may be effected by any suitable means, such as
by pivotting the lever, carrying the said rollers, to the rear wheel axle and guid-
ing it in a slideway upon a crank axle so that it may be adjusted and fixed.
according to requirements.
The arrangenient may be still further modified by placing the rollers behind
the gear wheel, or pinion, on the rear wheel axle, instead of in front, and the set
of gear wheels may be mounted upon the rear-wheel axle, so as to distribute the
load more evenly, and not to interfere with the cyclists movements in operating
the pedals.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what
I claim is:
1. In driving gear for velocipedes and other road vehicles two rollers (such
as d and d) over which the driving chain passes, and through the medium of
which the said chain may be thrown into gear with either of two chain wheels
of different sizes (such as a and b) for the purpose of varying the speed sub-
stantially as herein before described.
2. Driving gear for velocipedes or other road vehicles of the character herein-
before described in which a system, or series, of wheels of different diameters (such
as 6 1 2. ) is employed to vary the speed by throwing the chain into with
gear
one, or other, of the said gear-wheels substantially as hereinbefore described.
Dated this 12th day of February 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.