Improvements in
Year: 1896

page_text: Date of Application, 17th Oct., 1896
I, MARK THOMAS DENNE of Holford Works, Perry Barr, near Birmingham, in
the County of Stafford, Engineer, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in Velocipedes, and consists of an
improved method of fixing cranks, chain wheels, and other parts of cycles together,
which is more secure than the methods at present employed for attaching such
parts.
In carrying my invention into effect, when attaching a chainwheel to a crank,
I preferably employ a crank of the type known as a "banjo" crank, which is
provided with a rim of considerably larger diameter than the axle, while the
boss of the chain wheel is bored to correspond. The outer periphery of the said
rim upon the crank is provided with a series of grooves or serrations, while the
inner surface of the chain wheel boss has projections or serrations adapted to
engage with the grooves or serrations, respectively, upon the crank.
In order to prevent lateral displacement and to further secure the chainwheel
upon the crank, screws, rivets, or other fastenings may be employed, or the outer
edge of the rim of the crank may be spun or turned over into a countersink in
the chain wheel boss.
Dated this Fifteenth day of October. 1896.
COMPLETE SPECIFICATION.
Improvements in Velocipedes.
I, MARK THOMAS DENNE of Holford Works, Perry Barr, near Birmingham, in
the County of Stafford, 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:-
My invention relates to Improvements in Velocipedes, and has for its object
the provision of improved means for fixing cranks, chain wheels, and other parts
of cycles together.
In carrying my invention into effect, when attaching a chain wheel to a crank,
I preferably employ a crank of the type known as a "banjo crank," which is
provided with a circular rim of considerably larger diameter than the axle,
while the boss of the chain wheel is bored to correspond. The outer periphery
of the said rim upon the crank is provided with a series of grooves or serrations,

page_text: while the inner surface of the chain wheel boss has projections or serrations
adapted to engage with the grooves or serrations of the crank.
In order to prevent lateral displacement, and to further secure the chain wheel
upon the crank, screws, rivets, or other fastenings may be employed or the outer
edge of the rim of the crank may be spun or turned over into a countersink in
the chain wheel boss.
To enable my invention to be fully understood, I describe the same as applied
to the crank and chain wheel shewn in the accompanying drawings. Fig. 1 is
a plan of the crank and wheel, and Fig. 2 a section through the centre of same.
Fig. 3 is also a section through the centre of crank and wheel, shewing a modifica-
tion of same.
Referring more particularly to Fig. 1:-
A is the rim or boss upon the. crank which is first turned to a diameter A,
after which recesses d. d. are cut; the bottoms of the recesses being circular,
and of a diameter B. The boss C of the chain wheel is bored to a size which
would fit the diameter B, and has recesses the bottoms of which
are. of the
diameter A; thus the projections upon the crank correspond with the recesses in
the chain wheel boss, and the chain wheel being forced over the rim, is securely
held from turning, while any strain tending to revolve the rim within the hole is
equally distributed over the entire circumference.
To prevent lateral displacement, I may employ screws as shewn in Fig. 3 at e,
or rivets or other fastening or I may spin or turn over the edge of the rim upon
the crank as shewn in Fig. 2 at f.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
The combination with a rim or, boss, and the hole wherein it is adapted to fit,
of projections upon the said rim or boss adapted to engage with correspo
recesses formed in the hole, substantially as described.
Dead this 12th day of July 1907
MARK THOMAS DENNE.