Improvements in and relating to Driving Chains.
Year: 1889

page_text: Date of Application, 9th Jan., 1889
Complete Specification Left, 9th Oct., 1889-Accepted, 9th Nov., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Driving Chains.
I, GEORGE DOUGLAS LEECHMAN of 17 Manor Park Road in the parish of Willesden
in the county of Middlesex, Engineer do hereby declare the nature of this invention
to be as follows:-
My invention relates to pitch chains for driving velocipedes lawn mowing, and other
small machines, and it has for its objects, facilitating the replacement of broken
links, the ready alteration of the length of the chain, and a reduction in width and
weight.
To attain these ends 1 form the intermediate or alternate links of my chain in
two parts, and I fix them together by suitable screws, or rivets, the former for
preference.
Each half of the link consists of a plate with a small boss at each end. These
bosses are circular in form and are provided with holes. When the two parts of the
link are screwed or rivetted together by means of suitable screws or rivets passing
through the holes in the said bosses, the bosses form pins on which the connecting
links which may be of the type used on the "Humber" pattern chain, or of any
other suitable and convenient type-turn.
It will thus be seen that the screws or rivets sustain no wear, but are used merely
to keep the two parts of the double link together, thus they may be made much
smaller and lighter than usual, and as screws, have no tendency to work loose.
I countersink the holes in the double link so that the heads of the connecting,
screws or rivets do not stand proud of the link.
By this construction of chain I am able to materially reduce the width without
decreasing the wearing surface.
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
Royal Courts Chambers, 70, Chancery Lane, London, W.C.,
Agent for the Applicant.
COMPLETE SPECIFICATION..
Improvements in and relating to Driving Chains.
I, GEORGE DOUGLAS LEECHMAN, of 17 Manor Park Road, in the parish of Willesden
in the County of Middlesex, 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 :-
My invention relates to pitch chains for driving velocipedes, lawn mowing, and
other small machines, and it has for its objects facilitating the replacement of broken
links, the ready alteration of the length of the chain the reduction of width and
weight and the simplification of manufacture.
I attain these ends in the manner illustrated in the accompanying drawing in
which Figure 1. is a view in side elevation of one pattern of my improved chain and
Figure 2. is a view in plan thereof, partly in section. Figure 3 is a view in side
elevation of another pattern of the chain, and Figure 4. is a plan thereof, partly in
section.
Throughout these views similar parts are marked with like letters of reference.
The intermediate or alternate links A A etc. of my improved chain are formed in
two parts of identical shape. Each part of the link consists of a plate a having a

page_text: small boss a' at each end. These bosses are circular in form and are of a depth
slightly exceeding half the width of the connecting links B B etc. of the chain so
that when the two parts of each link A are screwed or rivetted, together the
links B B the bosses bb etc. of which are adapted to fit on the bosses a¹ a¹-will
freely turn thereon. The two parts of each of the links A A etc. are fastened
together by means of screws or rivets etc. passing through holes a² a² etc.
in the bosses a¹ a¹ etc. These connecting links B B etc. may either be solid of the
type illustrated by Figures 1. and 2-known as the "Humber pattern" chain-or
of the skeleton type as illustrated by Figures 3 and 4, or of any other suitable and
convenient type.
It will be seen that as the screws or rivets a etc. are only used to hold the two
parts of the links A A etc. together they sustain no wear the links B B etc. turning
on the outer surfaces of the bosses a¹ a¹ of the links A A etc.
Under these conditions the screws or rivets may be made of soft metal which
simplifies the manufacture of the chain if the links are rivetted together. As the
bosses a¹ a¹ on each plate a forming the link A butt against each other when the said
plates are fixed together to form a link, the rivets may be rivetted up tight without
binding the joints in the chain a feature not possessed by any other chain having a
plain rivet. When I connect the links together by screws-which affords an easy
and ready manner of altering the length of the chain or replacing broken or damaged
links I prefer to insert the screws alternately from each side of the links. As there
is no wear or friction on the screws there is no tendency for them to work loose.
Another feature possessed by my improved clain is that, as all the wear takes place
between the links of the chain and not hetween the links and the rivets or pins, the
links forming the joints can be hardened thus enabling the chain to be put together
with soft rivets.
A further advantage possessed by my improved chain is that as one screw or rivet
is sufficient to hold the two parts of each of the links A A etc. together, the Ichain
is not rendered useless by the breakage of one or more rivets or screws providing
that at least one rivet in each link is perfect. In cheap forms of my improved chain
I use but one screw or rivet in each link A, and in that case I do not drill a hole
through one of the bosses a¹ on each plate a.
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 ;-
1st. The improved chain constructed, arranged, and operating, substantially as and
for the purpose set forth.
2nd. In a driving chain, constructing the alternate links in two parts each having
bosses adapted to abutt against each other and to be held together by a screw or rivet
passing through one or more of the said bosses, and to form bearings for the con-
necting links to turn on, as set forth.
3rd. In a driving chain the combination of the plates a a having bosses a¹ a¹ at
each end and adapted to be fixed together by screws or rivets xx so as to form a solid
link A, and of the links B B adapted to fit over the bosses a¹ a¹ of the links. A A,
all combined, arranged, and operating, as and for the purpose set forth.
4th. The improved construction of chain, admitting of the hardening of the wearing
parts of the joints, of the use of soft rivets, and of the rivetting of the said rivets
hard up, as and for the purpose set forth.
DL: daw of October 1880
ROBT. ED. PHILLIPS, M.I.M.E.,
Consulting Engineer and Patent Agent,
Royal Courts Chambers, 70, 71 & 72, Chancery Lane, London, W.C.,
Agent for the Applicant.