Driving Gear and Brake Mechanism for Velocipedes.
Year: 1899

page_text: Date of Application, 28th Jan., 1899-Accepted, 27th May, 1899
COMPLETE SPECIFICATION.
Driving Gear and Brake Mechanism for Velocipedes.
I, OTTO GEHRKE, of 35, Kreuzbergstrasse, Berlin, in the Empire of Germany,
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:
The object of this invention is gear or mechanism for driving the treadle of
velocipedes and which is characterized by the fact that the pedal is not rigidly
connected with the ordinary driving gear but can turn independently thereof,
being only connected therewith when the pedal is depressed. In this arrange-
ment, a highly efficient transmission of power is obtained as the proportion of
leverage can be selected at will. Moreover a particularly simple and highly
efficient brake can be provided and can be actuated from the pedal lever by a
stronger pressure of the foot on one of the pedals.
In the accompanying drawings is shown one way of carrying the invention
into practice, Fig. 1 being a side view of a bicycle shown on the right hand side,
Fig. 2 a plan of the driving gear, Fig. 3 a side view of the same on the left
hand side and Figs. 4 and 5 detail views of the end of the pedal lever. The two arms
of the rear wheel fork a are connected together by an axis b upon which is mounted
a pair of intermediate wheels c, c', this axis being carried in ball bearings. The
wheels c, c', have ratchet teeth wherein gears a pawl d, d¹³, jointed to the shortest
end of the pedal lever e, e¹, turning on the fixed axis p, p¹. As the chain wheels
are inside and the levers e, e¹, outside the arms of the fork, the connection between
the pawl and the pedal lever is effected by a pin q of sufficient length. The axis p
does not co-operate with the axis b. When the pedal is depressed, the pawl
gears into the teeth and causes the intermediate wheel to turn. The motion of the
latter is transmitted in any suitable manner either by means of the chain
wheels g, gl, and the chain h or otherwise to the rear wheel. As each one of the
pedal levers accomplishes its return motion, the pawl is raised by a spiral spring f
and subsequently drops down without coming into contact with the intermediate
wheel until-in consequence of the eccentric attachment of the lever e, e¹,-it
comes again into gear with the said wheel. For the backward motion of the
pedals, both are connected together by a chain i guided over the roller k fixed to
the frame of the machine. When one of the pedal levers is depressed the chain
end connected to that pedal is pulled upon and the other pedal is correspondingly
raised. The fork arms a are so bent that they should not impede the motion of
the pin g.
The brake apparatus shown in Fig. 3 is actuated by the left hand pedal lever e
and consists of a ring n fixed to the left intermediate wheel c¹ and acted upon by
a brake lever o furnished with a brake block. This lever o turns on an axis fixed
to the frame of the machine and is provided with a second arm o¹ carrying an
adjustable pressure screw 7. The latter is so adjusted that, in the ordinary manner,
the lever o does not come into contact therewith, but should the latter lever be
depressed with more power than usual the rear end of the same would be pressed
with great force against the brake ring.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
:―
1. Driving gear for the pedal levers of velocipedes characterized by the rotation
-with the aid of the pawl 'd, d, of the intermediate wheels c, c¹, by means of the
pedal levers e, e¹, mounted eccentrically to the said intermediate wheels, these
pawls setting by means of suitable transmission gear-the driving wheel in
motion, and being thrown out of gear when the pedal levers accomplish their
return motion.
2. In driving gear of the kind above claimed a brake consisting of a lever o, o¹,
jointed to the frame, one arm of which acts on a brake ring n fixed on to the
intermediate wheel axis as soon as ever the pedal lever comes-in consequence of
extra pressure being developed in pedalling into contact with an adjustable stop
of the other lever arm.
Dated this 27th day of January 1899
CRUIKSHANK & FAIRWEATHER,
Chartered Patent Agents,
62, Saint Vincent Street, Glasgow, Agents for the Applicant.