Improvements in or connected with Cranks and Axles specially applicable for Bicycles.
Year: 1897

page_text: Date of Application, 16th Oct., 1897
Complete Specification Left, 18th July, 1898-Accepted, 10th Sept., 1898
PROVISIONAL SPECIFICATION.
Improvements in or connected with Cranks and Axles specially
applicable for Bicycles.
We, THE ANGULAR-HOLE MACHINE COMPANY LIMITED, of Dashwood House,
New Broad Street, in the City of London, Manufacturers, and ALFRED WOOD,
Junior, of Lily Bank, The Greaves, Lancaster, in the County of Lancaster,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention has for its object to provide improved means for attaching cranks
to their shafts whereby the said cranks can be more firmly fixed than heretofore
and readily removed from the shaft when desired, the said invention being especially
applicable for use in connection with the pedal cranks and axles of bicycles.
According to the said invention the portion of the crank shaft upon which the
crank arm is fixed is made of square or other suitable polygonal shape and the
crank arm is formed with a correspondingly shaped hole which will fit on to
the end of the crank shaft. The polygonally shaped end of the said shaft is
formed with saw cuts or slots communicating with a longitudinal hole in the
end of the shaft which is screw-threaded and into which a taper screw plug can
be introduced in such a manner that when the crank arm has been placed upon
the shaft and the said taper plug is screwed inwards the polygonally shaped end
of the shaft will be expanded to bear tightly against the sides of the aperture in
the crank arm and thus hold the latter firmly in position.
It will be understood that in order to remove the crank arm from the shaft it
is only necessary to loosen the said screw 'so as to allow the end of the said shaft
to contract slightly.
The arrangement herein before described possesses the great advantage that it
will not work loose in use as is frequently the case when a crank arm is fixed
upon a crank shaft by means of a key.
This 16th day al Octahan 1807
COMPLETE SPECIFICATION.
Improvements in or connected with Cranks and Axles specially
applicable for Bicycles.
We, THE ANGULAR-HOLE MACHINE COMPANY LIMITED, of Dashwood House,
New Broad Street, in the City of London, Manufacturers, and ALFRED WOOD,

page_text: Junior, of Lily Bank, The Greaves, Lancaster, in the County of Lancaster
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:
This invention has for its object to provide improved means for attaching cranks
to their shafts whereby the said cranks can be more firmly fixed than heretofore
and readily removed when desired, the said invention being especially applicable
for use in connection with the pedal cranks and axles of bicycles.
According to the said invention the portion of the crank shaft upon which the
crank arm is fixed is made of square or other suitable polygonal shape and the
crank arm is formed with a correspondingly shaped hole which will fit on to
the end of the crank shaft. The polygonally shaped end of the said shaft is
formed with saw cuts or slots communicating with a longitudinal hole in the
end of the shaft which is screw-threaded and into which a taper screw plug can
be introduced in such a manner that when the crank arm has been placed upon
the shaft and the said taper plug is screwed inwards the polygonally shaped end
of the shaft will be expanded to bear tightly against the sides of the aperture in
the crank arm and thus hold the latter firmly in position.
It will be understood that in order to remove the crank arm from the shaft it
is only necessary to loosen the said screw so as to allow the end of the said shaft
to contract slightly.
The arrangement hereinbefore described possesses the great advantage that it
will not work loose in use as is frequently the case when a crank arm is fixed
upon a crank shaft by means of a key.
To enable our invention to be fully understood we will describe the same by
reference to the accompanying drawing, in which:-
Figure 1 is a sectional elevation of a bicycle crank axle and cranks constructed
according to our invention; and,
Figure 2 is an end view of the same:
Figures 3 and 4 are an elevation and end view respectively of the axle detached;
and,
Figure 5 is an elevation of the taper screw.
a is the crank axle the ends b, b of which are, as shewn, made of square section
and e, e are the crank arms or cranks which are formed with square holes (prefer-
ably by means of what are known as angular hole drilling machines) and fit upon
the said ends b, b.
d, d are the screw threaded holes formed longitudinally in the ends b, b and e, e
are the saw cuts for allowing the expansion of the said ends. In the drawing
two saw cuts extending diagonally across the ends are shown, a single saw cut,
however, will allow of the desired expansion, and this cut may be made diagonally
or not as desired. f. are the taper screws which are inserted into the holes d, d.
In practice the taper is just sufficient to ensure that when the said screws are
"home" as shown in Figures 1 and 2, the axle ends b, b shall be expanded to
the desired extent.
We prefer that the screws should have flat heads, or heads only slightly rounded
as shown, and be screwed up by a "tommy," holes for receiving the teeth of which
are indicated at g, g.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:
1. The combination of a crank axle having an end of square or other polygonal
shape in transverse section and formed with a longitudinal hole screw-threaded
and with a saw cut or saw cuts, a crank arm fitted upon the said polygonal end
and a taper screw for expanding the said end, all substantially as, and for the
purposes, described.

page_text: 2. Crank axles and crank arms constructed and adapted to be fixed together,
substantially as herein before described and illustrated in the accompanying
drawing.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London,
Agents for the Applicants.