Improvements in the Manufacture of Driving Chains for Cycles and other such like purposes.
Year: 1897

page_text: Date of Application, 31st Aug., 1896-Accepted, 28th Aug., 1897
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Driving Chains for Cycles and
other such like purposes.
We, ERNEST CHARLES BRADLAUGH SMITH of 13 Avenue Road, Aston, Birmingham in
the County of Warwick Machinist, and SAMUEL BONSOR of Victoria Road, Tamworth, in
the County of Warwick, Accountant do hereby declare the nature of our said invention
and in what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:—
Our invention has for its object improvements in the manufacture of driving chains
for Cycles and other such like purposes, by which greater endurance is imparted to
the chain by our particular mode of manufacture and the nature of the parts
constituting the same.
Driving chains for Cycles and other such like purposes which are constructed of
links and joint pins and which drive over sprocket wheels are continually changing
the position of the links in their relation the one to the other for the reason that the
links are sometimes in a line the one with the other and sometimes curved round the
periphery of sprocket wheels and sometimes hanging in a flat curve on the under
side of the chain as in the case of Cycles which change of position is provided for by
the rivet joints which continually wear more or less loose which alters the length of
the chain and conduces to back-lash and vibration which our invention is designed
to obviate in a large degree and which we accomplish by making the rivet which is
so liable to wear hard at its central portion which forms the journal and sufficiently
soft at the ends to allow of the necessary enlargement to fasten it in the side links,
as, for instance by a rivet head, though the desirability for such a pin or pivot has
been known it has hitherto been found most difficult to produce in practise in a
satisfactory manner. Now by our new mode and means of procedure we overcome
the difficulties and produce the desired result in the following manner :-
In order that our invention may be clearly understood and more easily carried into
practical effect we have appended hereunto a sheet of drawings which give examples
of our tools and by which we will explain our invention but it must be understood
that the shape of the tools may be considerably varied so as to operate on a larger or
Sinaller number of rivets at once.
Figure 1 is a perspective view of such a plate or tool A as we use in the manufacture
of our pins or rivets a³.
Figure 2 is another form of tool in two halves A A.
Figure 3 is a broken off plan of another modification of tool.
Figure 4 is a cross section at 1. 2 Figure 3.
Figure 5 shows a plain rivet a³.
We take a plain plate of metal of any desired or convenient shape such as
A Figure 1 and drill or form therein any number of holes a² into which the pins a³
will fit so as to touch the hole all the way round, or in other words a fair fit, but with
the end or ends of the rivet projecting above or beyond the face of the plate as shown
at the right hand end of Figure 1, or the plate or tool may be made in two parts as
seen at Figure 2 with the pin a³ projecting on both faces and bound tightly between
Prins 77

page_text: the two plates by clamps or screws, or other means, or the tool may be about as thick
as the pins are long as seen at Figures 3 and 4 with counter-sunk or recessed
portions at around each pin end as there shown in plan and section. Now when the
pins are placed in such like tools I apply heat by means of a blow pipe, or blast, or
hot irons applied to the ends of the pins while they are embraced by the cooling
tools or their equivalents in such a manner that the centre of the pin which forms
the journal is kept cool and hard while the ends are softened so as to allow them to
be enlarged or rivetted in the links of the chain. That is to say we make our pins
from steel and harden them first. Then the pins are placed in the tools and the ends
are softened. Then they are placed in position in the chain links and then enlarged
or rivetted or otherwise fastened by the manipulation of the soft ends of the rivets
by which means we preserve the hardened central portion of the pin so as to wear
much longer. It will be quite evident that the plate or holder A may be a round
dise fixed on a spindle so as to be turned either vertically or horizontally and the
holder may take the form of a convenient tool for holding one or a few pins at once
such for instance as tongs with sufficiently massive heads to keep the centre of the
pin cool.
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
claim is
we
The improvements in the manufacture of driving chains for Cycles and other such
like purposes consisting of the particular process of manufacture by which the pins a³
are first hardened after which the heads of the pins are softened by the application of
heat while the pin is encompassed by a cool medium such as the tools illustrated on
the accompanying drawings and substantially as herein set forth.
Dated this 29th day of August 1896.