Improvements relating to Cycle and like Chain Wheels.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements relating to Cycle and like Chain Wheels.
I, WALTER BERNARD CHALLEN, of the Firm of Taylor and Challen, Limited,
of Derwent Foundry, Constitution Hill, in the City of Birmingham, Engineers,
do hereby declare the nature of this invention to be as follows:-
This invention consists of improvements relating to cycle and like chain
wheels, my object being to produce such wheels from wrought metal in a more
economical and expeditious manner than is possible by the present method of
manufacture.
I produce chain wheels in accordance with my invention from sheet metal,
preferably mild steel, of a thickness equal to or but slightly in excess of the
required finished width of the wheels. From such sheets and with any suitable
machine I punch or press out blanks or discs and subsequently pierce a central
eye or aperture through the same. By suitably formed punches and dies arranged
upon a hydraulic or power press or like machine, the peripheries of the discs
are then pressed and drawn in such a manner as to leave smooth and accurately
pitched projections properly shaped into teeth of the correct form for gearing
with the cycle or other driving chains.
I thus dispense with the ordinary milling or like cutting operations in the
construction of chain wheels in accordance with my invention, it being necessary
only to turn or face the sides of each wheel and to screw or otherwise finish its
central aperture, after the pressing operations hereinbefore described.
This ocul
AGAL 1907
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
and 13. Temple Street, Birmingham,
Agents for the Applicant.
Improvements relating to Cycle and like Chain wheels,
I. WALTER BERNARD CHALLEN. of the Firm of Taylor and Challen_Limited,
of Derwent Foundry, Constitution Hill, in the City of Birmingham, Engineers,
do hereby declare the nature of this invention and in what manner the same
ED27

page_text: is to be performed, to be particularly described and ascertained in and by the
following statement:-
:-
This invention consists of improvements relating to cycle and like chain
wheels, my object being to produce such wheels from wrought metal in a more
economical and expeditious manner than is possible by the present methods of
manufacture.
In the accompanying sheet of explanatory drawings to be hereinafter referred
to.-
Figure 1 is a plan and Figure 2 a sectional end view of the chain wheel
blank as first produced from the sheet metal, whilst Figures 3 and 4 are similar
views of the blank after passing through the periphery finishing tools. Figure 5
is an elevation, with part in section, of the finished wheel.
Figure 6 is a sectional plan of the finishing punch and die, and Figure 7.a
sectional elevation of the punch.
Figure 8 is a sectional elevation showing the wheel blank under operation
between the punch and the die, the section being taken through the line a b
Figure 6.
The same reference letters in the different views indicate the same parts.
I produce chain wheels in accordance with my invention from sheet metal,
preferably mild steel, of a thickness equal to or but slightly in excess of the
required finished width of the wheels. From such sheets and with any suitable
machine I punch or press out blanks such as A (Figures 1 and 2) having teeth
around its periphery, the said periphery of the blank being slightly in excess
(about 05 inch) of the required finished diameter of the wheel. The blank A
is then forced by the punch B through the die Cand its toothed periphery is
thus accurately formed to the required finished shape. The chain wheel so
formed is shown at Figures 3 and 4.
The die C is made to the exact shape and dimensions to give the finished
periphery of the wheel as shown at Figure 3, but the punch B is made sufficiently
smaller to leave an annular channel of about 08 inch in width all round the
periphery between the punch B and the die C. With such tools the surplus
metal around the periphery of the blank A. due to its diameter being in excess
of the required finished diameter of the wheel, will be caused to flow at right
angles to the fat faces of the blank and up the annular channel between the
punch and the die as the former tool passes through the latter. By thus setting
up a flow of the metal I am enabled to draw the periphery of the disc to the
required dimensions and to produce a bright and smooth surface for the chain
to work upon.
After leaving the die C the blank or wheel has the fin like projection A¹
(Figure 4) cut or faced off in any convenient manner; the wheel after such facing
is shown at Figure 5.
I employ my finishing tools in combination with any suitable hydraulic or
other press or machine of sufficient power.
By the application of my invention I am enabled to dispense with the ordinary
milling or like cutting operation in the construction of chain wheels, it being
necessary only to turn or face the sides of each wheel and to screw or otherwise
finish its central aperture, after the pressing operations herein before described.
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:
1. The improved process of manufacturing cycle and like chain wheels com-
prising the subjection of metal blanks having peripheries larger than the required
finished peripheries of the wheels, to a pressure sufficient to cause the surplus
metal at the said peripheries to flow at right angles to the faces of the blanks,
substantially as and for the purpose described.

page_text: a
2. In the manufacture of cycle and like chain wheels from metal blanks, the
combination with a pressing machine of a punch as B and die as C having
flowing metal channel between them, substantially as described and as illus-
trated.
UGKU
TO
Oh day of August LORD.
MARKS & CLERK,
18, Southampton Buildings, London, W.C.,
and 13, Temple Street, Birmingham,
Agents for the Applicant.