IMPROVEMENTS IN CRANKS FOR VELOCIPEDES
Year: 1880

page_text: LETTERS PATENT to Josiah Turner, of the City of Coventry, in the County of
"
Warwick, Manager of the Coventry Machinists Company, for an Invention of
"IMPROVEMENTS IN CRANKS FOR VELOCIPEDES."
PROVISIONAL SPECIFICATION left by the said Josiah Turner at the Office
of the Commissioners of Patents on the 7th July 1880.
JOSIAH TURNER, of the City of Coventry, in the County of Warwick,
Manager of the Coventry Machinists Company. "IMPROVEMENTS IN CRANKS FOR
VELOCIPEDES."
The object of this Invention is to provide a facile means for attaching cranks to
their axles, and of ensuring the tightening up of the same should they become
loose.
To effect this object I cone the ends of the axle to receive the cranks, and groove
the cones longitudinally to receive a key or feather. The crank sockets I bore to
fit the conical ends of the axle, and provide them with keys to enter the longitudinal
grooves, and thereby lock the cranks to the axle.
On the ends of the axle beyond the cones I cut screw threads to receive lock.
nuts, which are countersunk into the sockets of the crank arms, and I thus form
simple and efficient fastenings for the detachable cranks. Should the cranks
become loose by rough or continued wear, it will only be necessary to screw up the
nuts, and the cranks will be forced further onto the cones, and thereby fixed
securely in place.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by the
said Josiah Turner in the Great Seal Patent Office on the 6th January 1881.
JOSIAH TURNER, of the City of Coventry, in the County of Warwick,
Manager of the Coventry Machinists Company. "IMPROVEMENTS IN CRANKS
FOR VELOCIPEDES."
The object of this Invention is to construct the cranks of velocipedes in such a
manner as to allow of their being rapidly and securely attached to or removed from
their axles, and also to permit of their being tightened up should they become loose
by wear.
In carrying out this Invention I cone the ends or the axle to receive the
improved cranks, and groove these coned ends longitudinally to receive a key or
feather.
The sockets of the crank arms I bore to fit the conical ends of the axle, and
provide them with keys to enter the longitudinal grooves, and thereby lock the
cranks to the axle.
On the extreme ends of the axle beyond the cones I cut screw threads to receive
circular nuts, which are countersunk into the sockets of the crank arms, and I thus
form simple and efficient fastenings for the detachable cranks. Should the cranks
become loose by rough or continued wear, it will only be necessary to screw up the
nuts, and the cranks_will be forced further onto the cones, and thereby fixed
securely in place.
The construction of these improved detachable cranks and the manner in which
they are secured to the ends of the axles will be clearly seen on reference to the
accompanying Drawing, wherein I have shewn one of the cranks as applied to the
axle of a bicycle fitted with ball bearings.
Fig. 1 is an end elevation showing the crank in position; Fig. 2 is a transverse
vertical section of the same, and Fig. 3 is a detached view of the crank arm showing
its inner face.
In these Figures the same letters of reference indicate corresponding parts.
A is the axle; a, the coned end of the same to which the crank arm is fitted;
a' is a groove cut in the coned end a and longitudinally thereof, for the purpose of
receiving a steel key or feather b¹ projecting beyond the inner periphery of the
coned socket b of the crank arm B.
The extreme end a³ of the axlo A is threaded to receive a circular nut C, which
nut is provided on its outer face with holes c, to allow of its being screwed well
home by a spanner provided for the purpose, having pins formed thereon to enter
the said holes c.
The outer face of the crank arm B is bored out to receive the circular nut C, and
when all the parts are in position the nut C will be countersunk, and its outer face
will be flush or nearly so with the outer face of the crank arm B.
On tightening up the nut C on the threaded end as of the axle, the coned socket
of the crank B will be forced tightly onto the coned end a of the axle, and be
prevented from turning thereon by reason of the feather b' with which the said
crank socket is provided, and which enters or interlocks with the grooves a¹.
I would remark that with the view of obtaining a better grip, and avoiding all
chance of shearing off the key or feather b', the said key b' should extend
longitudinally the entire length of the groove a¹ cut in the coned end of the axle.
Should the crank arm wear loose upon the axle, it will merely be necessary to
tighten up the nut C, thereby forcing the crank arm B further onto the coned end a
of the axle A.
If desired the interlocking steel key or feather may be inserted in the coned end
of the axle so as to project beyond the periphery thereof, and the corresponding
groove may be cut in the interior of the coned socket of the crank arm.

page_text: Should the coned socket of the crank arm from any cause become jammed upon
the coned end of the axle, and it be desired to remove the crank or cranks so as to
reduce the width of way required for the bicycle, it will only be necessary to
partially unscrew the outer cap of the ball bearing, whereby a steady pressure will
be applied to the inner face of the crank arm, and the coned socket thereof will be
easily forced from off the coned end of the axle. This will be understood on
reference to the Drawing, in which D represents the outer cap of the ball bearing.
Having now set forth the nature of the said Invention of "Improvements in
Cranks for Velocipedes," and explained the manner of carrying the same into effect,
I wish it to be understood that I claim,-
Constructing detachable cranks for velocipedes with conical sockets, which fit
onto the coned ends of the axles and interlock therewith by means of feathers and
grooves, substantially in the manner and for the purpose herein shewn and
described.
In witness whereof, I, the said Josiah Turner, have hereunto set my hand and
seal, the Third, day of January, in the year of our Lord One thousand
eight bundred and eighty one.
JOSIAH TURNER. (L.S.)