Improvements in Driving Gear for Velocipedes.
Year: 1898

page_text: Date of Application, 4th Mar., 1898-Accepted, 10th Sept., 1898
COMPLETE SPECIFICATION.
Improvements in Driving Gear for Velocipedes.
We, JULIUS ALEXANDER NICOLAJ RASMUSSEN, of Tojhuset, Armorer, and
CHARLES BENTON HART RASMUSSEN, of 2, Kalkbranderivej, Machine Constructor,
both in Copenhagen, in the Kingdom of Denmark, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be parti-
cularly described and ascertained in 'and by the following statement:-
In velocipedes in which the transmission of the motive power is effected by
bevel wheels, instead of by the ordinary chain gear, efforts have been made to
reduce the friction either, by the employment of very fine bevel wheels, the shape
of the teeth being as mathematically accurate as possible, or by causing the pinion
to rotate in ball-bearings or round a bolt placed through two walls.
None of these arrangements however, entirely obviates friction arising from the
slight shifting in the bearings which is unavoidable during the working of the
machine.
The present invention consists in a driving gear for chainless cycles in which
the teeth of the wheels are made of such a form, that their accurate and free gear-
ing is not affected by the above mentioned shifting, as they only touch each other
at points and not as usual in a line.
In the accompanying drawing
Figure 1 shows a horizontal section through the crank shaft bearing of a cycle
constructed according to the present invention.
Figure 2 shows a perspective view of part of the specially formed driving wheel.
Figure 3 is a section through the wheel between two teeth.
Figures 4 and 5 are sections on the lines a-b and c-d of Figure 3 respectively,
and
Figure 6 is a perspective view of part of the specially formed pinion.
As will be seen from Figures 2, 4 and 5 the teeth m of the driving wheel A
are so made that their transverse section is limited by convex curves on the sides,
while the teeth n of the pinion B (Figure 6) are each made in the form of a
frustrum of a cone cut out of the wheel itself.
The ordinary lines of contact between the wheel and the pinion teeth will then
be reduced to points of contact, and the slight shifting of the axles or bearings
during the working will not add to the friction. The teeth of the pinion being
furthermore cut out of the wheel itself the division of the teeth may be brought
about with an accuracy corresponding to the division plate.
The arrangement described offers in this respect a great advantage compared
with the above mentioned formerly adopted means, as the drilling of holes, the
screw-cutting for the ball-cups and the like prevent a similar accuracy in the
division of the teeth.
To spread and diminish the wear of the conical teeth n of the pinion they may
be inserted in sockets p (Figure 1) of tempered steel kept in their place by means
of a common disc g placed on the wheel-nave.
From the crank-axle the motion is transmitted by the above described wheels A

page_text: and B to the driving shaft C and further to the axle of the rear wheel by a gear-
ing similar to the one above described but in the latter case the wheel is fixed
to the end of the shaft C and the pinion B to the axle of the rear wheel.
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 driving gear for chainless cycles having a driving wheel A
arranged on the crank-axle and a similar wheel on the rear end of the driving
shaft C the teeth of the said wheels A being formed so that their transverse sec-
tion is limited by convex curves; pinions B on the fore end of the driving shaft C
and on the axle of the rear wheel respectively whose teeth n, which may if desired
be provided with sockets 2 of tempered steel, and formed conical in shape, sub-
stantially as described.
2. In the pinion B referred to in Claim 1 the arrangement of a plate g engag-
ing the ends of the conical teeth and fixed to the wheel-nave in such a manner
that all the sockets ? placed over the teeth are kept in their place by a single
plate substantially as described.
Dated this fun day of Mare
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.