Improvements in Pitch Chains.
Year: 1891

page_text: COMPLETE SPECIFICATION.
Improvements in Pitch Chains.
I, CHARLES ALEXIS SEBIN of 33, Rue de l'Orillon, Paris, France, Chain
Maker, 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 relates to improvements in pitch chains and it has for its object
to enable those parts of the joints which are subjected to friction to be made of
hardened steel so as to prevent elongation and loss of pitch and consequent breaking
of the chain. It is known that hardening prevents the elongation, and increases
the durability, of the chain but in making the joints by rivetting or upsetting as
usual it is impossible to apply it to all the parts subject to friction whereas by the
improved construction of this invention the whole of the friction is borne by
parts which have been hardened.
The invention is illustrated in the accompanying drawings, forming part of this
Specification, wherein
Figure 1 represents a face view of the improved pitch chain;
Figures 2, 3, and 4 are sections on lines 1-2, 3-4, and 5-6 respectively.
a is the joint-pin made of drawn steel, which is represented as of hexagonal
section although it may be made of square, rectangular, or polygonal form, rivetted
at the ends against the outer pair of links b. This pin a passes through a bush c
of hardened steel having a bore corresponding in form to the pin a and fitting
thereon as one. d is a sleeve, also of hardened steel, fitting loose upon the bush c
and provided at one or both extremities with flats (as shewn in Figure 4) fitting
in correspondingly-shaped eyes in the inner pair of links e e so as to turn with
them on the bush c. f is an outer sleeve or friction roller, also of hardened steel,
which turns freely upon sleeve d between the links e e. Thus the outer pair of
links in whose eyes the pin a fits are connected together by the said pin and by
the bush e so that the links b pin a and bush c turn together as one the bush c
forming the axis of the joint on which the sleeve d turns whilst the inner pair of
links e are connected together by, and turn with, the sleeve d which by its
shouldered ends acts as a distance piece to hold the links e apart.
It will be obvious that the form and dimensions of the parts of which these
improved pitch chains are composed, may be varied and that such chains may be
applied for transmitting motion generally, as in velocipedes and other machines.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
1. The herein described improvement in the construction of pitch chains, con-
sisting in the combination of the hard steel bush c and pin a connected to and
turning as one with the outer pair of links, as described, with the hard steel
sleeve d turning with the inner pair of links upon the bush c, as described.
2. The combination, in the same joint, of the three tubular parts-viz. the bush c
fitting on the pin a, the sleeve d fitting upon c, and the outer sleeve or roller f
surrounding the whole, all substantially as herein before shewn and for the purpose
specified.
Dated this 20th a
1001
By A. M. & Wm. Clark,
C. A. SEBIN.
53. Chancery Lane, London, Chartered Patent Agents.