Improvements in Cycle Driving Mechanism.
Year: 1897

page_text: Date of Application, 8th Feb., 1897-Accepted, 17th July, 1897
COMPLETE SPECIFICATION.
Improvements in Cycle Driving Mechanism.
I, SIMON PIERRE FRANÇOIS LEHMкGHL, of 122, Malabhastraat, The Hague,
Netherlands, Engineer, do hereby declare the nature of my invention for "Improve-
ments in cycle driving mechanism," and in what manner tho same is to he
performed, to be particularly described and ascertained in and by the following
statement:-
My invention relates to a cycle crank which is furnished with two rings, of which
oue is fastened to the crank, and the other bears the pedal; and to a ring-formed
cycle crank consisting of two rings of which one is fastened to the crank axle and
the other bears the pedal. The object of this invention is to shorten the path of
the pedal. To show that it is possible in this way to shorten the path of the pedal,
serves Sheet I. On the crank a b is fastened the ring, and the ring ", can turn
round this ring, but only in one direction. The pedal is fastoned instead of to
the crank to the ring, If during the downstroke the ring, cannot turn round,,
then it is clear that the pedal runs through the path P, P, P,; the end of the
crank running through the path α, The pedal being arrived in the position P,,
the ring, with the pedal begins to turn back round the ring, while the whole
system turns round the crank axle C. Then it is clear that the pedal can run
through the path P, P. P₁, the oud of the crank running through the path a, a, a,.
In the same manner it is possible that the centre of the pedal runs through the
path N, M, S or N₁, M, S and paths between these.
The shortening can be tit.
It is impossible to stop otherwise but with half power namely but in the point q.
This is a disadvantage of the system.
Sheet II and Sheet III show how this invention is to be performed. Sheet II
Fig. 1 shows a side elevation of a cycle crank furnished with two rings. Fig. 2
shows a horizontal section of the same. On the crank axle a is fixed in the usual
manner the crank c c. On this crank is fastened by means of the rectangular
plates P and P, and by means of the little screws S the ring r, on which is fixed
the ratched wheel W.
At the outside of this ring is made a balltrack (race). The ring, has a balltrack
(race) at the inside and the balls b fasten the two rings together but do not prevent
them from turning round each other. On the ring, is fixed a click (pawl) d that
is held in position by means of a little spring e. This click prevents the ring r,
from turning round the ring r, in one direction but permits turning in the other
direction.
'The eye K of the ring, serves to fasten thereto the pedal. If this eye K is
fixed by means of a screw to the eye K, of the crank, then the system is in use
like an universal crank.
Sheet II Fig. 3 shows the side elevation of another ring formed orank of which
Fig. 4 shows a horizontal section. On the crank axle A is fixed the ring .. At
the inside of this ring is made a balltrack (race) and on the outside are teeth W
such as of a wratched wheel. At the outside of the ring r, is also made a ball track

page_text: and the balls b fasten the rings together. On this ring r, is fixed the part I, which
is furnishod with a click d with tho little spring e.
Sheet III Fig. 1 shows the side elevation of a ring formed crank which is
made dustproof, Fig. 2 being a horizontal section of the same. The ring is
fastened to the craukaxle a in the usual manner. At the inner sido of this ring
is mado a ball track and a number of teeth W forming a ratched wheel. On the
ring, at the outside is made a ball track and tho balls b fasten these rings together.
On this are fixed the click d and the ring formed parts 2, which make the
construction dustproof and also the part L in the eye K of which the pedal must be
fastened. By means of the screw S can the ring r. be fastened to the ring 1, and
then it has in use the same effect as an universal crank.
Sheet III Fig. 3 shows the side elovation of a ring formed crank which is
made dustproof and of which the crank axle is situated within the circumference
of the rings.
Fig. 4 shows a horizontal section of the same.
On the crank axle a is fixed
the ring, on which a number of teeth P are fixed. The ring 1' is fixed theroto
by means of the balls b and on this ring are fastened the click & and the spring 6,
the parts z, which make the construction dustproof and the part L, in the eye K
of which the pedal must be fastened.
LMNO shows one of the paths through which the pedal can run.
Fig. 5 shows the side olevation of a ring formed crank, the centre of the rings of
which is the same as the centre of the crank axle a.
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 :-
1. A crank furnished with two rings, of which one is fastened to the crank and
the other can turn round the former, one being furnished with a ratched wheel,
the other with a click.
2. A ring formed crank, consisting of two rings, of which one is fastened to the
crank axle, the other can turn round the former and one of the two being furnished
with a ratched wheol, the othor with a click.
Noted this 2nd day of Wohmione 1907