An Improved Expanding Crank for Velocipedes and other Machines.
Year: 1895

page_text: Date of Application, 23rd Dec., 1895
Complete Specification Left, 23rd Sept., 1896-Accepted, 7th Nov., 1896
PROVISIONAL SPECIFICATION.
An Improved Expanding Crank for Velocipedes and other
Machines.
1, HENRY JOSEPH WARSOP 4 Bertha Terrace Brierley Street Nottingham do
hereby declare the nature of this invention to be as follows:-
:-
I claim a new way in getting a longer leverage when the force is being applied
to the crank and shorter leverage where there is no force on the said crank by
means of an eccentric motion at the leverage end of the said crank.
The disc which forms part of the eccentric is fixed in the leverage end of the
said crank running in any suitable bearing.
The pedal is fixed stationary to the said disc in any suitable way to formn
the eccentric motion at the leverage end of the said crank, which is the means of
lengthening and shortening the leverage of the said crank.
Dated this 21st day of December 1895.
An Improved Expanding Crank for Velocipedes and other
Machines.
1, HENRY JOSEPH WARSOP of No. 4 Bertha Terrace, Brierley Street,
Nottingham, 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 my invention is to form an expanding crank-for velocipedes and
other machines whereby, when the propelling power is applied to the greatest
advantage, the leverage of the crank is gradually lengthened; and shortened again
when the propelling force is applied with less effect.
And in order that my said invention may be more fully understood and readily
carried out and into effect, I shall now proceed more particularly to describe the
same; and for that purpose shall refer to the several figures on the annexed sheet
of drawings wherein the same letters of reference indicate corresponding parts in
all the figures.
Fig. 1 is an elevation ehowing one of my improved cranks complete-and partly
in section, and showing also the relative positions of the pedal in dotted lines at
four points of its revolution.
Fig. 2 is a longitudinal section in plan of my crank through Kine 1-2 (Fig. 1).
In these views C is the crank secured by the usual means on the axle F which
imparts motion to the velocipede or the like.
The leverage or outer end of the crank is formed with a circular ring A, in
which is turned a semicircular or suitable shaped ball race for the friction balls to
turn in.
A disc B-also formed with a ball race or path around its outer circumference

page_text: turns freely in the ring A on the balls D. D, which are kept in place in the crank
by the adjustable covering ringE screwed into ring A of the crank, and suitably
secured therein.
At any suitable distance from the centre of disc B, I firmly fix therein a
suitable axle M for carrying the pedal P; which is also firmly attached to the
axle M in such a manner that when the foot is placed on the pedal P, and when
turning the crank thereby, the disc or eccentric B turns on the balls D. D in the
ring A as the crank is turned by the foot on the pedal P; which remains hori-
zontal or nearly so-during each revolution. By this means the length of the
leverage of the crank from M to F is gradually increased from the position 1-
Fig. 1 where it is the shortest on its upward stroke past 3 to the position 2,
where the leverage from M to F is the longest; then in the direction of the
arrows round past 4 to 1 again; and so on during each revolution of the
crank.
Thus on pedalling from positions 3 to 2, where the power is applied to the
greatest advantage, the length of the crank from F to pedal P is gradually
increased; and from the positions 4 to 1-where the power is applied to the
least advantage-the length of the crank is gradually decreased.
The circle S shows the path of the centre of ring A; and the circle T the path
of the centre of axle M and pedal P.
When back-pedalling, if the pedal be turned over until the axle M coincides
with the centre 7-8, the times of lengthening and shortening the crank are
reversed to suit the altered times when the power is required to be exerted to the
greatest and least advantage respectively.
In some cases I may have two or more series of friction balls D. D in the
crank end A; and I may also have one or more series of friction balls in the
centre of the pedal, and also in the outer end of same, in any desired combination.
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 :-
1st. In cranks for velocipedes and the like the means of lengthening and
shortening the distance from the axle to the pedal by means of one or more
eccentrics fastened to the pedal in combination with one or more suitable friction
bearings in the crank end for the eccentric or eccentrics to turn in, all for the
purposes mentioned and substantially as herein before described and shown in the
drawings herewith.
2nd. In cranks for velocipedes and the like fitting the outer end thereof with
one or more eccentrics turning in suitable bearings in the same in combination
with a pedal firmly fixed out of the centre of same therein, all substantially
as described herein for the purposes named and as shown in the drawings
herewith.
3rd. In cranks for velocipedes and other machines the arrangement and
combination of parts as shown in Figs. 1 and 2, for the purposes mentioned and
substantially as herein before described, and shown in the drawings herewith.
Dated this 22nd day of September 1896.
H. WALKER HILL,
2 Church Gate, Nottingham, Agent for the Applicant.