Improvements in and connected with Driving Mechanism for Bicycles.
Year: 1898

page_text: Date of Application, 15th Feb., 1898-Accepted, 1st Oct., 1898
COMPLETE SPECIFICATION.
[Communicated from abroad by FRANK JOHN WADMAN, of 106, Matson Avenue,
Onondaga, in the County of Onondaga, State of New York, Printer, and
EMIL LAASS, of 300, McBride Street, Syracuse, in the County of Onondaga,
State of New York, Solicitor of Patents, both in the United States of
America.]
Improvements in and connected with Driving Mechanism for
Bicycles.
I, WILLIAM PHILLIPS THOMPSON, F.C.S., M.I.M.E., of the Agency for Foreign
Patent Solicitors, 322, High Holborn, in the County of Middlesex, 6, Lord Street,
Liverpool, and 6, Bank Street, Manchester, both in the County of Lancaster, and
Lower Temple Street, Birmingham, in the County of Warwick, Civil Engineer,
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 improvement in propelling mechanism for bicycles,
and it has special reference to that class of mechanism in which reciprocating
rods or pitmen are employed for transmitting rotary motion from a crank shaft
to the driving wheel. The main object of the invention is to provide mechanism
by which great power and speed can be obtained with comparatively little
exertion on the part of the rider of the bicycle, and furthermore, the object is
to produce a construction which shall be simple and durable and also very
efficient in its operation, and at the same time will present a neat appearance.
And to that end the invention consists in the novel construction and com-
bination of parts as hereinafter fully described and specifically set forth in the
claims.
In the annexed drawings, Figure 1 is a side elevation of a bicycle equipped
with my improved propelling mechanism, Figure 2 is an enlarged detail side
view of said mechanism, Figure 3 shews a plan view of the same, and Figure 4
is a further enlarged sectional view of the so called crank-hanger or bracket,
Figure 5 is an enlarged transverse section shewing the construction of the ends
of the rods by which said rods are jointly pivoted to the single wristpin on the
gear, and Figure 6 shews said ends of the rod separated from each other.
In referring to the drawings a a¹ represent the rear-fork members, and b b the
rear braces of the bicycle frame A, which frame is provided with the usual
bracket c. The fork-member a is bent outwardly further than the fork-
member a¹ and is joined to the rear brace b by means of a vertically disposed
plate d to permit the application and operation of my improved propelling
mechanism which will now be explained.
In the bracket c is journalled an oscillatory shaft e provided with two inde-
pendently operating pedal-levers f f¹, the lever f being rigidly secured thereto,
and the lever f¹ journaled on said shaft.
On the shaft e is journaled a rock-arm g preferably formed integral with the
journaled lever f¹, and rigidly secured on said shaft is a similar arm g¹.

page_text: B represents the driving-wheel, to the hub of which is secured a pinion i. On
the aforesaid plate d of the frame is pivoted a gear-wheel j which meshes with
the pinion i, and said gear receives rotary motion from the oscillatory arms g, g',
by means of two rods or pitmen which are pivoted at their front ends to the
rock-arms gg respectively, and are pivoted jointly at their rear ends to a single
wrist-pin on the gear wheel j, which, by means of the aforesaid pinion i, imparts
accelerated motion to the driving wheel B.
are
The rock-arms g gl are each provided with a slot m in which the pitment
pivoted, said slots allowing the pitmen to be shifted toward and from the
shaft e to increase or diminish the leverage of said arms and vary the thrust of
the pedal-levers accordingly.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what I claim is:-
1. In a bicycle, the combination with the frame and driving-wheel, of two
levers operating independently of each other, pedals imparting oscillatory motion
to said levers, pitmen receiving reciprocating motion from the levers, and gears
transmitting rotary motion from said pitmen to the driving-wheel, as set forth.
2. The combination with the frame and driving-wheel, of a shaft journaled
on the frame, a lever fixed to said shaft, a lever journaled on said shaft, separate
pedals operating said levers, pitmen connected to the levers, and gears trans-
mitting rotary motion from said pitmen to the driving-wheel, as set forth.
3. The combination with the frame and driving-wheel, of a pinion secured to
said, wheel, a gear-wheel mounted on the frame and meshing with said pinion, a
single wrist-pin on said gear-wheel, pedal-levers mounted on the frame, rock-
arms actuated by said pedal-levers, and two pitmen connected respectively to the
two rock-arms and pivoted in common to the aforesaid wrist-pin, as set forth.
Dated this 15th day of February 1898
W. P. THOMPSON & Co.,
322, High Holborn, London, W.C., Patent Agents for the Applicant.