IMPROVEMENTS IN THE CRANKS OF VELOCIPEDES WHEREBY THE LENGTH OF THE STROKE MAY BE AUTOMATICALLY VARIED AT THE WILL OF THE RIDER
Year: 1885

page_text: the Rider.
I HENRY WILLIAM GODFREY of The Hythe, Staines, in the County of Surrey
Engineer do hereby declare the nature of my Invention for the IMPROVEMENTS IN
THE CRANKS OF VELOCIPEDES WHEREBY THE LENGTH OF THE STROKE MAY BE
AUTOMATICALLY VARIED AT THE WILL OF THE RIDER to be as follows:-
I use an hollow crank axle, upon each end of which I fix, a suitably shaped
sleeve or case, into which, the moving crank arm slides telescopically. Inside the
hollow axle I place a small solid spindle, which rotates freely in its place, to each
end of this spindle I fix a small pinion, which engages a toothed rack corre-
spondingly cut upon the sliding crank arms, or instead of the pinions, I fix a short
arm which engages a pin suitably fixed on the moving crank arm-]
-It then follows
that motion imparted to one arm in any direction, must be communicated to the
other, through the solid spindle being thus connected with the respective, sliding
arms.
When it is required to vary the throw of the crank, the rider simply presses
with his foot, upon the pedal when the cranks are in a vertical position, if to
lengthen them he must press upon the pedal at the bottom of the stroke, when the
sliding arms are thrust simultaneously from their respective guides or cases, but if
it is desired to shorten the throw, the pressure must be given as the foot passes the
the top stroke, when the crank arms will be driven back into their cases, and the
throw consequently shortened-To prevent any undue tendency of the cranks
shifting involuntarily in their cases, I introduce a small spring, suitably arranged,
Upon this spring is a tooth or teeth which engages a corresponding notch or
notches upon the sliding crank arm, this spring is slightly in compression while
engaging the notches, and must be overcome and the tooth forced from its position
simultaneously with the motion of the arm-The coupling of the crank arms by
the means stated is not absolutely necessary, as each arm may work separately and
independently of the other and be retained in their respective positions by the
spring or catch before mentioned. Or the crank arm may be fixed to the axle in
the usual manner, and the case carrying the pedal may be made to slide upon its
outer end.
Signed this Thirteenth day of March 1885.

page_text: the Rider.
HENRY WILLIAM GODFREY of The Hythe Staines, in the County of Middlesex
Engineer 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 :-
I use a hollow crank axle upon each end of which I fix a suitably shaped sleeve
or case into which the moving crank arm slides telescopically. Inside the hollow
axle I place a small solid spindle which rotates freely in its place, to each end of
this spindle I fix a small pinion which engages a toothed rack correspondingly cut
upon the sliding crank arms or instead of the pinions I fix a short arm which has a
projecting pin carrying a loose block which slides in a groove cut in the moving
crank arm.
It then follows that motion imparted to one in any direction must be
communicated to the other through the solid spindle being thus connected with the
respective sliding crank arms. When it is required to vary the throw of the crank,
the rider simply presses with his foot upon the pedal when the cranks are in
a vertical position, if to lengthen them he must press upon the pedal at the bottom
of the stroke when the sliding arms are thrust simultaneously from their respectivo
sleeves or cases, but if it is desired to shorten the throw the pressure must be given
as the foot passes the top stroke when the crank arms will be driven back into
their cases and the throw consequently shortened To prevent any undue tendency
of the cranks shifting involuntarily in their cases I introduce a small spring suit-
ably arranged upon this spring is a tooth or teeth which engages a corresponding
notch or notches upon the sliding crank arm, this spring is slightly in compression
while engaging the notches and must be overcome and the tooth forced from
its position simultaneously with the motion of the arm. The coupling of the
crank arms by the means stated is not absolutely necessary, as each arm may work
seperately and independently of the other, and be retained in their respective
positions by the spring or catch before mentioned or the crank arms may be fixed
to the axle in the usual manner and the case carrying the pedal may be made to
slide upon its outer side.
In order that my said Invention may be more fully understood I will proceed to
describe the drawing annexed.
DESCRIPTION OF THE DRAWING.
Fig. 1 is a front elevation with part of the cover plate removed Fig. 2 is
a section on line a b. Fig. 3 is a side elevation of the crank with the pedal fitted
thereto. Figs. 4 & 5 are views of the cover plate L. Fig. 6 is a side elevation.
Fig. 7 is a front elevation of the same with part of the cover plate removed
shewing the arrangement when using a rack and pinion. A is a hollow axle on
which is fitted the sleeve or case B. C is the crank arm D is an arm having a
projecting pin which carries the friction block E which slides in the groove G cut

page_text: in the crank arm C. H is a recess in the crank arm C to allow the moving of the
arm D which is fitted onto the spindle F it then follows that any motion imparted
to one crank must through the spindle F be communicated to the other K is
a spring with projections ii fitting into the notches k k¹ this spring prevents the
crank moving involuntarily, the spring may be fitted with a screw if necessary for
adjustment M is a feather on the crank C and slides in a groove in the sleeve or
case B.
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
First. Variable throw cranks for Velocipedes constructed in such a manner
that the length of throw may be automatically varied at the will of the rider
substantially as described.
Secondly. The combination of parts for the construction of variable throw
cranks substantially as described.
Dated this 19th dow of Denamhan 100%