Improvements in Driving Mechanism for Velocipedes.
Year: 1893

page_text: Date of Application, 8th Feb., 1893
Complete Specification Left. 21st Mar., 1893-Accepted, 13th May, 1593
PROVISIONAL SPECIFICATION.
Improvements in Driving Mechanism for Velocipedes.
1, JÖRGEN CAJUS STALLKNECHT, of Horsens, Denmark, Manufacturer, do
ereby declare the nature of this invention to be as follows:-
This invention relates to an improved toothed-wheel gearing adapted to be inserted
n the boss or nave of the driving wheel of the velocipede, and which serves to
mpart to the same a greater speed of revolution than that of the crank axle, with
less friction than with the usual forms of gearing.
The said gearing comprises two connected planet wheels of unequal size, mounted
on a stud fixed in the boss, the larger of which engages a fixed toothed-wheel
secured to the wheel-fork of the velocipede, whilst the smaller gears with a
toothed-wheel keyed on the crank axle.
The improved gearing being enclosed in the boss of the wheel is effectually
protected from dust and dirt.
In the accompanying drawings,
Fig. 1 is a part transverse section of a velocipede wheel with gearing arranged
according to this invention, and,
Fig. 2 is a diagrammatic part elevation of the same.
Of the four toothed-wheels, a, b, m and n, the toothed-wheel a is fixed by
screwing or keying on the crank axle x, said axle being rotated by means of the
cranks on which are mounted the pedals (not shown in the drawings).
The wheels and bare formed in one or fixed to each other and rotate about the
axle y which is fixed in the boss of the driving wheel, which boss in this case is
considerably enlarged and made of dished or cup shape.
The wheel m is mounted on the end of the wheel-fork of the velocipede in such a
manner as to be prevented from rotating.
The wheel a gears with the wheel band has a greater number of teeth than the
latter, whilst the wheel n which has approximately the same number of teeth as the
wheel a, gears with the wheel m which has approximately the same number of teeth
as the wheel b.
It will thus be seen that if the wheel a be actuated by means of the pedals, the
axle y
will then, since the wheel m cannot rotate, move around in the same
direction as the wheel a. If the number of teeth is properly chosen, the axle y, and
with it the driving wheel, will receive a greater speed of rotation than the wheel a
or the crank axle.
For example if the wheel a has 26 teeth, the wheel 15 teeth, the wheel n
25 teeth, and the wheel m 16 teeth, the wheel a will, each time when the axle y
moves once round the axle x, only make (1÷x) that is to say of a
will move
revolution, or vice versa when the wheel a moves round once, the axle
round times, the wheel b having a tendency to rotate the wheel a (x2) times
in a backward direction, each time the axle y moves once round the axle .
A driving wheel of 40 inches diameter will thus for every revolution of the
cranks, move through the same distance as a wheel of 63.41 inches upon which the
cranks act directly, or the gearing-up is 63-41.
The friction in this mechanism is much less than with other toothed-whee
gearing, because the speed of revolution of the toothed-wheels is in this case
5 considerably less, as the axle y follows the movement of the cranks.
CUL.... 1902
J. C. STALLKNECHT,
By L. W., per F. B.

page_text: 1
COMPLETE SPECIFICATION.
Improvements in Driving Mechanism for Velocipedes.
I, JÖRGEN CAJUS STALLKNECHT, of Horsens, Denmark, Manufacturer, 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 improved construction of toothed-wheel gearing
adapted to be inserted in the boss or nave of the driving wheel of a velocipede, the
object being to impart to such driving wheel a greater speed of revolution than
that of the crank axle, with less friction than with the usual forms of gearing
heretofore adopted.
My improved gearing comprises two connected planet wheels of unequal size,
mounted on a stud fixed to the boss of the driving wheel, and the larger of which
engages a toothed-wheel fixed to the wheel-fork of the velocipede, whilst the
smaller wheel gears with a toothed-wheel keyed on the crank axle.
The improved gearing can be enclosed in the boss of the wheel so as to be
effectually protected from dust and dirt.
In the drawings filed with my Provisional Specification,
Fig. 1 is a part transverse section of a velocipede wheel with gearing constructed
and arranged according to this invention, and
Fig. 2 is a diagrammatic part elevation of the same.
a, b, m and n are the four toothed-wheels. The toothed-wheel a is fixed by
screwing or keying on the crank axle .c, which is rotated by means of the cranks k
on which are mounted the pedals (not shown in the drawings). The wheels n and b
are formed in one piece or fixed to each other, and rotate about the study which is
fixed in the boss of the driving wheel which in the example shown is considerably
enlarged and made of dished or cup shape so as to partly enclose the gearing.
The wheel m is mounted on the end of the wheel-fork of the velocipede in such a
manner as to be prevented from rotating. The wheel a gears with the wheel and
has a greater number of teeth than the latter, whilst the wheel n, which has
approximately the same number of teeth as the wheel a, gears with the wheel m
which has approximately the same number of teeth as the wheel b.
It will thus be seen that if the wheel a be actuated by means of the pedals, the
stud
will since the wheel m cannot rotate, move around in the same direction as
the wheel a. If the number of teeth is properly chosen, the stud y, and with it the
driving wheel, can be driven at a greater speed of rotation than the wheel a or the
crank axle.
:
For example if the wheel a have 26 teeth, the wheel 15 teeth, the wheel n
25 teeth, and the wheel m 16 teeth, the wheel a will, each time when the axle
moves once round the axle.c, only make (1-13.) that is to say of a revolution,
or vice versa when the wheel a moves round once, the axle y will move round times,
the wheel b having a tendency to rotate the wheel a (8.) times in a backward
direction, each time the axle y moves once round the axle <.
A driving wheel of 40 inches diameter will thus for every revolution of the
cranks, move through the same distance as a wheel of 63.41 inches upon which the
cranks act directly, or the gearing-up is in the ratio of 40 to 63.41.
The friction in this mechanism is much less than with other toothed-wheel gearing,
because other speed of revolution of the toothed-wheels is in this case considerably
less, as the axle y follows the movement of the cranks.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
In a velocipede, driving mechanism comprising two connected planet wheels of

page_text: unequal size mounted on a stud fixed to the boss of the driving wheel of the
velocipede the larger of the two wheels gearing with a fixed toothed wheel secured
to the wheel fork of the velocipede whilst the smaller wheel gears with a toothed
wheel keyed on the crank axle substantially as described and shown, whether or
not the boss of the driving wheel be so formed as to partly enclose the said driving
mechanism.
L 1000
J. C. STALLKNECHT,
By L. W., per F. B.