Improved Crank for Cycles.
Year: 1894

page_text: Date of Application, 22nd Dec., 1894-Accepted, 28th Jan., 1885
Improved Crank for Cycles.
OSCAR WERNICK, of Schutzenstrasse of Potsdam near Berlin, in the Empire of
Germany, Merchant, do hereby declare the nature of my said 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 a crank or treadle-lever for cycles and has for its object
to more advantageously transmit the power or pressure exerted on the pedals.
This I attain by providing means for effecting a greater leverage for each down-
stroke of the crank and for the automatic return of same into the noumal position,
the path to be travelled by the foot on the up-stroke being thereby shortened.
My improved crank consists of two or more pivotally connected arms, preferably
cm ved, and subject to the action of a sping in such manner that on each down-
stroke such spring is put under tension corresponding to the extent of outward
movement of the outer arm of the crank and, on the up-stroke, forces said aim
mto its original or normal position again. The arrangement is also such that the
tension of the spring may be regulated at will.
In order that my invention may be thoroughly understood will now describe
same with reference to the accompanying drawing in which :-
Fig. 1 is a side view of the crank, the full lines showing the pedal arm in its
shortened or normal position and the dotted lines in the lengthened position.
Fig. 2 18 a front view of same,
Fig. 3 a vertical section on a larger scale drawn on line - of Fig. 1.
Fig. 4 is a vertical section drawn on line y-y of Fig. 3 and
Fig. 5 is a part plan view and part horizontal section of Fig. 4.
In the example shown in the drawings, the crank or lever cousists of the arm a
keyed on the axle of the cycle and the arm 6 carrying the pedal p
The arm is
arranged between the forks a¹ of the arm a and pivotally connected to same by
bolt c.
The arms a and b are preferably curved in order to give them a better
appearance, by thus curving the parts the arrangement may at the same time be
such that a fee and unimpeded movement is left for the feet in pedalling. The
arms provided on its side with a strong pine passing through the curved slot h
In one of the forks a' and engaging the hooked end of a spiral spring s; the other
end of the latter is secured to a sleeve g forming part of the sping-casing d and
pivotally arranged on the bolt c This casing dis secured to the forks a¹ but may
be readily released as hereafter more fully described.
The crank is subjected to the action of springs in the following manner: On
the downward thrust of the foot the pedal arm is depressed to such an extent
that the pedal now descubes the arc instead of a, the sping being also strained
to a like degree by the pin e engaging with same and sliding in the slot along
with the aim ; immediately after the crank reaches its position cones ponding to
about the position indicated by line to and the pressure of the foot is released from
the ascending pedal, the springs acts on the arm band forces same backwards,
until the normal position is reached.
In order to regulate the tension of the spring s, the arrangement is such that
after loosening or unscrewing the bolt c screwed in the forks a', the casing together
with sleeve g may be turned by inserting a suitable tool in the holes d' of the
casing d. The latter is secured by means of pins or lugs ƒ having bevelled or

page_text: hook-like ends engaging in corresponding holes m in the forks a', or in noy other
suitable manner. The pins are bevelled in such manner that on turning the casing d
in the direction shown by the arrow (Fig. 4), the lugs of the latter clear the holes
of the fork a' after the bolt c is somewhat unscrewed; the casing may thus be
turned half round so as to increase the tension of the spring, whereas the return
of the casing is prevented by the pins engaging in the holes m
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. Improved crank for cycles, cousisting of two or more curved arnis pivotally
connected to each other, the outer arm, after being actuated by the pressure on the
treadle, being returned to its normal position during the up-stroke by the action of
a spring, substantially as described and shown in the drawing.
2 In an improved crank for cycles as claimed in Claim I a spung (s) hooked
on a pin (e) of arm (b) and thus participating in the movements of the latter,
said spring being put under tension on each down-sti oke of the crank and
automatically forcing the arm (b) into its original position, thereby shortening the
path to be travelled by the foot during the up-stroke of the pedal, substantially as
described and shown in the drawing.
3. In combination with a crank for cycles as described in the foregoing claims, &
device for regulating the tension of the spring (s) secured to a sleeve of the
casing (9), consisting of pins (f) suitably arranged on the casing and provided with
bevelled or hook-like ends which engage with correspondingly-formed holes of
arm (a), substantially as described and shown in the drawing.
Dated the 22nd day of Danamba 1001
E. P. ALEXANDER & SON,
19, Southampton Buildings, London, W.C., Agents.