Improvements in or relating to Chain Wheels for Driving Purposes.
Year: 1893

page_text: Date of Application, 2nd Sept., 1893
Complete Specification Left, 4th June, 1894-Accepted, 4th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in or relating to Chain Wheels for Driving Purposes.
I, CECIL WAGENER HOLMES of The Leicester Cycle Works, Friday Street,
Leicester, Cycle Manufacturer, do hereby declare the nature of this invention to
be as follows:-
The
This invention relates to chain wheels, particularly those used upon cycles, and
more especially the larger or driving chain wheel, the invention having particular
relation to the interchangeability and ready application and removal of the wheel.
Upon the axle or other part to which the wheel is to be attached, but usually
the crank axle, 1 secure by keying or other suitable means a boss or hub having a
flange against which the wheel proper can fit and a screwed cylindrical portion
upon which a ring nut may be screwed to hold the wheel in position. One or
more portions of the flange are cut away as a clutch the wheel being provided with
projecting or embossed lugs adapted to engage with the recesses in the boss.
wheel itself is not provided with any boss in the ordinary sense of the term, being
preferably quite flat and of substantially the same thickness throughout excepting
at the lugs and rim. The nut may be provided with radial holes for the purpose of
receiving a pin spanner or it may be provided with flats by which it can be turned.
The crank would preferably be of one of the known forms of detachable cranks.
Where this device is to be applied to the hub of a road wheel the construction
would be the same but the hub would take the place of the before mentioned boss.
With this arrangement the chain wheel can easily be removed in case of accident
or for the purpose of altering the gearing by employing a wheel having more or
less teeth, both ring nut and chain wheel having sufficiently large openings to pass
over the crank without requiring its removal from the axle, all that is necessary
being to remove the pedal.
Dated this 29th day of August 1893.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Chain Wheels for Driving Purposes.
I, CECIL WAGENER HOLMES of The Leicester Cycle Works, Friday Street,
Leicester, Cycle Manufacturer, do hereby declare the nature of this invention and
in what manner the same is to be performed, to he particularly described and
ascertained in and by the following statement :-
This invention relates to chain wheels, particularly those used upon cycles, and
more especially the larger or driving chain wheel, the invention having particular
relation to the interchangeability and ready application and removal of the wheel.
Upon the axle or other part to which the wheel is to be attached, but usually
the crank axle, I secure by keying or other suitable means a boss or hub having
a flange against which the wheel proper can fit and a screwed cylindrical
portion upon which a ring nut may be screwed to hold the wheel in position. One
or more portions of the flange are cut away as a clutch the wheel being provided

page_text: with projecting or embossed lugs adapted to engage with the recesses in the boss.
The wheel itself is not provided with any boss in the ordinary sense of the term,
being preferably quite flat and of substantially the same thickness throughout
excepting at the lugs and rim. The nut may be provided with radial holes for
the purpose of receiving a pin spanner or it may be provided with flats by which
it can be turned. The crank would. preferably be of one of the known forms of
detachable cranks.
Where this device is to be applied to the hub of a road wheel the construction
would be the same but the hub would take the place of the before mentioned boss.
With this arrangement the chain wheel can easily be removed in case of
accident or for the purpose of altering the gearing by employing a wheel having
more or less teeth, both ring nut and chain wheel having sufficiently large openings
to pass over the crank without requiring its removal from the axle, all that is
necessary being to remove the pedal.
In the accompanying drawings I have illustrated only the application of this
invention to the chain wheel of a crank axle as other applications will be easily
understood with the assistance of these drawings and the description.
Figure 1 is a back view of the parts.
Figure 2 is a perspective view of the screwed boss or hub.
Figure 3 is a section through wheel and boss.
Figure 4 a section through the wheel only.
Figure 5 a perspective view of the nut and
Figure 6 of the spanner suitable for turning it.
A is the chain wheel having a central opening A' large enough to fit over
the screwed portion B¹ of the boss B. Around the opening A' are segmental
lugs A² whose interior curved surfaces are adapted to fit over the reduced circular
portions B² of the boss B while the larger circular portions or lugs B³ of the
boss fit the open spaces A³ between the lugs A2 so that when the wheel and the boss
are placed together as in Figure 3 they are held rigidly together as if formed in
one piece. The nut C is adapted to screw on to the screwed portion B' of the
boss B and when the nut is screwed up the boss and the wheel are held rigidly
together. For the purpose of screwing up the nut radial holes or recesses C' may
be provided to receive the pin or projection D' of the circular or pin spanner Ď
by which the nut can be easily turned. If the crank E be permanently keyed or
fixed on to the shaft so that it cannot be removed, or if the crank E be formed in
one piece with the boss or otherwise permanently connected thereto, the wheel A
and nut C must be made with sufficiently large openings to pass over the crank.
If however the crank E be of the detachable kind and can be easily removed from
the shaft it will only be necessary for the opening A¹ in the wheel to be sufficiently
large to pass over the axle. Perhaps the most convenient arrangement is to form
the crank E and boss B in one piece as shown in Figures 2 and 3 of the drawings
so that the one key or cottar passing through the hole E' of the crank will secure
both crank and boss to the axle so that the wheel and its connecting parts can be
entirely removed when it is required to apply a new wheel or change it for one of
a different number of teeth.
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 :-
1. In an attachment device for chain wheels the combination with a chain wheel
such as A A' A' A³ of a boss such as B B¹ B2 B3 substantially as described and
illustrated in the accompanying drawings.
2. In an attachment device for chain wheels the combination with a boss such
as B B1 B2 B3 of a crank formed in one piece or permanently connected therewith
substantially as described and illustrated in the accompanying drawings.
3. In an attachment device for chain wheels the combination with a boss such

page_text: as B B¹ B' B³ and wheel such as A A' A' A' of a ring nut such as C having an
opening large enough to pass over the crank substantially as described and
illustrated in the accompanying drawings.
Dated this 10th day of May 1894.
CECIL W. HOLMES.
W. P. Thompson & Boult,
Agents for the Applicant.