Improvements in Driving Mechanism for Bicycles, Automobiles, and other Machines.
Year: 1899

page_text: Date of Application, 12th Dec., 1899-Accepted, 13th Jan., 1900
COMPLETE SPECIFICATION.
Improvements in Driving Mechanism for Bicycles, Automobiles,
and other Machines.
I, FRANK WILSON WUNDERLICH, of 84, Gray Street, in the Town of Arlington,
County of Middlesex, State of Massachusetts, United States of America, Book-
keeper, 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:-
My invention relates to improvements in driving mechanism for bicycles, auto-
mobiles and other machines; and the object of my invention is to provide a more
efficient means of keeping the chain in place; to reduce the number of rubbing
surfaces and thereby to reduce the friction; to reduce the number of parts; and
to simplify and cheapen the construction.
In the drawings illustrating the principle of my invention and the best mode
now known to me of applying that principle,
Fig. 1 is a perspective view showing the driving chain in engagement with the
sprocket wheel.
Fig. 2 is a section on the line A-A of Fig. 1.
Fig. 3 is a side elevation of a modified form of my new driving mechanism;
and
Fig. 4 is a section on line B-B of Fig. 3.
a is a sprocket wheel provided with teeth b. Journalled in the outer portion
of the wheel and near the base portion of each tooth b is a shaft c upon the ends
of which are mounted rollers d. The convex surface or rim portion of the roller
is smooth and not grooved.
The side links e of the chain are formed with a notch f which adapts them
to engage the rollers d; and the shafts c are so placed that when the side links e
are in engagement with the rollers d, the chain is held out of contact with the
peripheral or rim portion g of the wheel. This construction avoids the friction
which takes place between the rim portion of the wheel and the chain. Dirt and
grit accumulating on the rim portion of the ordinary wheel increase its diameter,
thereby causing a tightening of the chain and greatly increased pressure and
friction between the wheel and chain.
In the modification shown in Figs. 3 and 4, the teeth of the sprocket wheel
are dispensed with. The projecting walls of the notch in the side-links of the
chain are elongated and thus serve to prevent lateral displacement of the chain.
The advantages of my present construction are: first, fewness of parts, thus
cheapening and simplifying the construction; second, fewness of rubbing sur-
faces; third, reduction of friction due to structural features, the result so much
sought after in driving mechanism for bicycles and motor vehicles; fourth,
practical efficiency; and fifth, simplicity in construction and cheapness in
manufacture.

page_text: Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is: :-
The combination of a chain, the side links of which are notched to engage and
bear upon rollers; a wheel provided with teeth; a plurality of shafts mounted
in said wheel; and a plurality of rollers mounted on said shafts, said rollers
engaging in notches in the side links of said chain and holding said chain out
of contact with the rim of said wheel; the teeth of the sprocket wheel entering
between the side links of the chain and preventing lateral displacement of said
chain.
Dated this 12th day of December 1899
HERBERT HADDAN & Co.,
Agents to Applicant, 18, Buckingham Street, Strand, London.