Improvements in and in the Manufacture of Pitch Chains.
Year: 1891

page_text: Date of Application, 21st July, 1891
Complete Specification Left, 16th Apr., 1892-Accepted, 21st May, 1892
PROVISIONAL SPECIFICATION.
Improvements in and in the Manufacture of Pitch Chains.
I HANS RENOLD of Green Lane Manchester in the County of Lancaster
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to the chains designed to be employed in the transmission
of rotary motion. Such chains consist of metal links jointed together as is well
understood. It would be of great advantage if the pitch of the links would remain
constant during the life of the chain but in practice the wear at the joints causes
the whole chain to lengthen so that the pitch of the links is gradually increasing so
long as the chain is in use. A former invention for which Letters Patent No. 1219
of the year 1880 have been granted to me had for its object to lessen this tendency
of the chain to increase in length. I connected together the inner links of the
chain by means of tubes which were secured by each end in the eyes of such links
the result being that cach joint pin had a bearing extending across the said inner
links so that the rate of increase in pitch was greatly reduced. The object of my
present invention is to still further increase the durability and practical efficiency
of the chain. Owing to the absence of shoulders upon the joint tubes it has been
difficult to firmly rivet the tube ends in the link eyes and at the same time to keep
the links at the required uniform distance apart. To obtain these shoulders I
shrink or tightly force an outer tube over the first tube such outer tube being
shorter than the inner tube. I prefer to make these tubes and the joint pins of
good cast steel and for facility of production I make the tubes of sheet metal bent
into a tubular form as mentioned with reference to the first tube in the Specification
of my former invention. The ends of the outer tube are left rough so as to aid in
preventing the turning of the inner tube in the link eyes. To lessen the wearing
tendency I harden and if necessary temper the tubes or compound tube and the joint
pin leaving the parts as hard as possible without being too brittle for their purposes.
As the parts are then too hard to rivet I soften the ends of the joint pin and of the
inner tube. For this purpose I purpose to use highly heated melted lead.
I place
the parts in holders adapted to contain a number of the parts. In the case of the
tubes a perforated plate or carrier may be used the tubes being placed in position
with one end of the inner tube projecting downward through a perforation. The
carrier being floated or placed upon the lead the ends of the tubes become softened.
The joint pins may be similarly placed or clamped in holders with their ends pro-
jecting above and below. Any suitable form of holder or carrier may be used
the intention being that the holder or carrier shall check the transmission of heat
to the wearing parts of the pins and tubes. After the partial softening the tubes
may be riveted in the links the outer tubes keeping the links at a regular determined
distance apart. In some cases bowls are mounted to revolve upon the outer tubes.
These are made of steel and may or may not be hardened. I sometimes grind the
bores of the hardened bowls or tubes with a lap to render them true. After the
tubes have been riveted in place as aforesaid I sometimes grind the outer sides of
the links to remove projecting parts of the tubes and irregular prominences on
the links and to produce truer and more parallel surfaces. I mass a number of the
chain sections together upon the table of a grinding machine and subject the
sections to the action of the grinder. The sections are reversed and the other sides
are ground. I may fix the sections in holders or carriers which can be reversed so
as to subject both sides of the sections to the grinder. I may also grind the inner
faces of the outer links. The sections are lastly connected together by means of

page_text: the outer links and pins which are secured in the eyes of the outer links by riveting
as usual.
.
T
T
2
2001
DUTTON & FULTON,
1, St. James Square, Manchester, Agents.
COMPLETE SPECIFICATION.
Improvements in and in the Manufacture of Pitch Chains.
I HANS RENOLD of Green Lane, Manchester, in the County of Lancaster,
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 and accompanying drawings
:-
My invention relates to the chains designed to be employed in the transmission
of rotary motion. Such chains consist of metal links jointed together as is well
understood. It would be of great advantage if the pitch of the links would remain
constant during the life of the chain but in practice the wear of the joints causes
the whole chain to lengthen so that the pitch of the links is gradually increasing so
long as the chain is in use. A former invention for which Letters Patent No. 1219
of the year 1880 have been granted to me had for its object to lessen this tendency
of the chain to increase in length. I connected together the inner links of the
chain by means of tubes which were secured by each end in the eyes of such links
the result being that each joint pin had a bearing extending across the said inner links
so that the rate of increase in pitch was greatly reduced. The object of my present
invention is to still further increase the durability and practical efficiency of the chain.
Owing to the absence of shoulders upon the joint tubes it has been difficult to firmly
rivet the tube ends in the link eyes and at the same time to keep the links at the
required uniform distance apart. To obviate this defect I provide each joint tube
with shoulders.
In the accompanying drawings Fig. 1 illustrates the improved formation of a
joint tube a a representing the ordinary pins and the improved joint tubes.
Each tube is shouldered down at so that the parts which fit in the eyes of the
inner links ce are a little less in diameter than the middle part of the tube. In
the example the two ends of each joint tube are turned a little excentric with
respect to the middle portion of the tube. My object in doing this is to obtain a
greater thickness of metal on the side which is subject to reduction during the
ordinary working of the chain. It will be seen that the parts are so put together
as that in each case the thicker parts of the shells of the tube ends will receive the
frictional wear of the pin a. I turn the ends of the pins and tubes slightly conical
as shown and force the parts together before riveting, less riveting being required
which is an advantage especially when the parts have been hardened as herein before
mentioned. Fig. 2 illustrates an alternative method of obtaining shoulders upon the
tubes. In this example outer tubes are tightly shrunk upon inner tubes 62 the
outer tubes being made equal in length to the required distance apart of the inner
links. I prefer to make the tubes and joint pins of good cast steel and to lessen
the wearing tendency I harden and if necessary temper the tubes and the joint pins
leaving the parts as hard as possible without being too brittle for their purposes.
As the parts are then too hard to rivet I soften the ends of the joint pins and of
the tubes or of the inner tube 62 as the case may be. I place the parts in holders
adapted to contain a number of the parts. In the case of the tubes a perforated
plate or carrier may be used the tubes being placed in position with one end of the
tube projecting downward through a perforation as indicated in Fig. 3. A large
number of the tubes can thus be treated at one operation. The tubes being lifted
together by means of the holder are placed with their ends resting on a metal plate

page_text: which has been raised to a red heat and the tubes are allowed to remain in contact
with the plate until the ends have become softened in a suitable degree. The metal
plate besides serving to carry the tubes assists in checking the upward transmission
of heat to the central part of the tube which it is my object to leave hard. On
renoval from the plate the tubes may be placed upon a cold slab or be plunged
into a cooling fluid. The other ends of the tubes are then softened in the same
manner. The joint pins may be similarly placed or clamped in holders with their
ends projecting above and below, the ends of the pins being softened in the same
manner as the tubes. Any suitable form of holder or carrier may be used for the
tubes or pins and if preferred melted lead might be used in the softening process
but I have found the heated plate to be more advantageous. After the partial
softening the tubes may be riveted in the links the outer tubes keeping the links at
a regular determined distance apart. In some cases bowls are mounted to revolve
upon the outer tubes as indicated at e in Fig. 1.
These bowls are made of steel and may or may not be hardened. I sometimes
grind the bores of the hardened bowls or tubes with a lap to render them true.
After the tubes have been riveted in place as aforesaid I sometimes grind the outer
sides of the links to remove projecting parts of the tubes and irregular prominences
on the links and to produce truer and more parallel surfaces. I mass a number of
the chain sections together upon the table of a grinding machine and subject the
sections to the action of the grinder. The sections are afterwards reversed and the
other sides are ground. I may fix the sections in holders or carriers which can be
reversed so as to subject both sides of the sections to the grinder. I may also grind
the inner faces of the outer links c¹. The sections are lastly connected together by
means of the outer links and pins which are secured in the eyes of the outer links
by riveting as usual.
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. The chain partly composed of links connected together in pairs by means of
tubes formed with shoulders at which keep the links c' at a fixed distance apart
as set forth.
2. The chain composed of links connected together by means of joint pins a and
tubes b made of cast steel hardened or hardened and tempered and softened at the
ends by contact with heated metal substantially as and for the purpose set forth.
3. The method of softening the ends of steel pins and tubes for use in the
manufacture of pitch chains substantially as set forth and indicated.
4. The chain composed of links connected together by means of joint pins and
tubes of cast steel the parts being formed treated and put together as set forth and
indicated.
Dated this 14th day of April 1901
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.