Improvements in the Manufacture of Pitch Chains.
Year: 1887

page_text: [Communicated from abroad by JOSEPH ANDREW JEFFREY, of Columbus, County of
Franklin, United States of America, Manufacturer.]
Improvements in the Manufacture of Pitch Chains.
I, HAROLD IMRAY of No. 28 Southampton Buildings, Chancery Lane, in the
County of Middlesex, Fellow of the Institute of Patent Agents, 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 the manufacture of pitch chains as I will describe referring
to the accompanying drawings.
Figure 1 is a face view of a strip of steel, wrought iron, or other suitable metal,
from which may be cut side bars adapted for my improved chain.
Figure 2 is an edge view of Figure 1.
Figure 3 is a view of one of the finished side bars.
Figure 4 is a section of Figure 3.
Figure 5 is an edge view of Figure 3.
Figure 6 is a plan view of two of the bars in position.
Figure 7 is a side view of a tube from which can be cut the thimbles or tubular end
bars.
Figure 8 shews the thimble ready for insertion.
Figure 9 is a section of a link after the parts have been secured together.
Figure 10 is a side view of the same.
Figure 11 shows the pintle detached.
Figure 12 is a plan view, partly in section, of the chain.
Figure 13 shows a modification in which the thimbles are made in sections.
Figure 14 shows a modification of the tubular end bar.
Figure 15 shows a rectangular link made in accordance with my invention.
In the drawings A A represent the side bars of the links. They may be of any
desired shape, as, for instance, straight as shown in Figure 15, or curved as shewn in
Figures 5, 9, and 12. They are formed of strips or bars of metal of such dimensions
ID 877

page_text: and weights as are required. For ordinary purposes, I find that the bars do not
need to be so thick or wide as to prevent thein from being easily swaged into shape.
However, so far as the side bars are concerned I do not wish to be limited to making
them in this way.
At one end of each side bar there is a circular or other shaped seat, B, adapted to
receive one end of the tubular end bar C. By preference I also provide each of these
seats with a notch b.
The tubular end bars (or thimbles) are short sections of tubing, preferably of steel
tubing, and are of substantially the right length to project through the side bars and
be flush with their outer faces when the chain is finished.
After these thimbles are cut into proper lengths, they are inserted in the seats B, B
securely fastened by riveting or upseting, or by brazing, sweating, or any of the
methods for fastening together two pieces of metal.
At I have shown a key driven firmly into the notch or key seat b; and, when
desired, there may be a corresponding key seat in each end of the thimble. By one
or other of these means a rigidity of connection is secured and this thimble becomes
a tubular end bar of the link.
At the opposite end of the link its side bars are provided with pintle seats D, D, one
or both of which may be provided with notches or key seats d.
E is the pintle, circular in cross section throughout except that by preference, it is
provided with a lug, spline or feather e adapted to enter one of the key seats and
thus prevent the pintle from rotating relatively to either. of the side bars in which
it is thus mounted. F is the head of the pintle, and ff are short spurs or lugs
projecting from its opposite end.
After the parts of the chain thus described are assembled accidental displacement
of the pintles may be prevented by slightly bending outward the spurs ff. Or the
projecting end of the pintle may be slightly rivoted or upset against the adjacent face
of the side bar, thus dispensing with the spurs.
When it is desired to use an anti-friction roller G it may be placed over the tubular
end bar before the side bar is secured to the ends of the thimble.
:―
Among the advantages which are incident to my invention are the following:-
1. Great strength in proportion to weight is attained, from the fact that the side
bars can be made with the fibre or grain running lengthwise, while, at the same time
all danger of weakening from unequal tension at the junction of the side bars and
end bars is avoided.
2. Great accuracy in the length of the links can be attained.
3. Great accuracy in the fit of the articulating parts is insured.
4. Economy in manufacture.
5. Great durability, and immunity from increase of length of chain during use
whereby a proper tracking of the chain upon the sprocket wheels may be had; a
matter of great importance where high speed and high tension are required.
These capabilities are readily attained in my invention, as will be understood when
it is remembered that the side bars can be produced in great quantities with almost
unerring accuracy by the use of many of the well known machines for punching and
swaging, and that steel tubing of great uniformity of bore, of outside diameter and
contour can be produced at moderate cost.
The locking of the pintles in their seats d d insures that the wear shall occur at
the points where the pintles engage with the tubular end bars.
And the durability of these parts may be further increased by slightly tempering
or otherwise hardening the engaging surfaces of both the tubular end bars and
the pintles, or either of them.
In Figure 13 each end bar is made in two sections, one of which is secured to
its respective side bar. This construction has some advantages. For instance the
rollers can be applied after the thimbles have been secured to the side bars, and
if either side bar or the thimble needs replacing at any time, such parts can be
taken out and duplicates put in. This is a quite important matter, particularly
in large chains for exceedingly heavy work, to which a construction of this kind

page_text: 5
is especially applicable and wherein each side bar is a heavy piece of metal
requiring considerable labour to produce, finish and secure to its respective thimble
section.
Under some circumstances I propose to make the ends of the thimbles of somewhat
reduced size, in order to effectually prevent the side bars from being forced too far
upon the ends of said end bars.
As shown, these reduced ends are of uniform diameter throughout thus forming
shoulders but these ends might be made tapering and yet secure substantially
the same results.
In Figure 14 the ends of the tubular end bar are slightly flattened or slabbed
off and their seats in the side bars are correspondingly shaped, whereby the placing
of the upper and lower edges of the side bars in parallel planes is facilitated.
In Figure 15 I have shown a rectangular link as contradistinguished from a
U shaped link.
In this figure both end bars are formed of tube sections or thimbles, CC, like
those of the other figures, except that their outer surface is cylindrical and of
uniform diameter from end to end, instead of having their ends different in form.
In this figure the alternate side bars H H may be duplicates of each other ; each
bar having at its ends, duplicate pintle seats, each provided with a notch to receive
the spline or feather e of the pintle.
In the chain shown in figure 13 the tubular end bars may be each made in two
parts of about equal lengths separate from each other on the lines x x (Figs. 13
and 15). Or the tubular end bars may extend from one side bar across the entire
length or width of the link to the opposite side bar; in which case the adjacent end
of the side bar may have a seat of such diameter as will receive the end of the tubular
end bar; or it may have a smaller seat of sufficient size to receive the pintle, as
indicated at g Figure 15.
While I prefer to make both the side bars and tubular end bars of steel, yet it is
apparent that many of the advantages which are incident to my invention may be
attained by the use of malleable iron side bars, or wrought iron side bars. In fact,
some of these advantages are obtainable with the use of tubing made of metal other
than steel.
It will be readily understood that chains containing my invention can be run under
high tension and at high speed with much less wear of the sprocket wheels than results
from the use of chains of the ordinary construction whereby they are specially
valuable under conditions which make it inconvenient (or otherwise undesirable) to take
out the sprocket wheels and put in new ones.
While I have set forth the best way now known to me for carrying my invention
into effect, I do not wish to be limited to the details herein explained, because many
modifications will naturally suggest themselves to any one skilled in the art of chain
making, and without departing from the spirit of my invention.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is
1. A chain link having a tubular end bar formed of steel to receive the pintle,
substantially as set forth.
2. A chain link having a tubular end bar formed of steel, a steel pintle, and side
bars connecting the pintles and the tubular end bar substantially as set forth.
. A chain link having the side bars formed separately from each other, a
pintle, and a tubular end bar formed separately from the side bars, substantially as set
forth.
4. A chain link having the side bars formed separately from each other the pintle
and the tubular end bar for the pintle formed separately from and rigidly to the side
bars substantially as set forth.
5. A chain link having the side bars formed separately from each other, the pintle,

page_text: and the tubular end bar formed in separable sections, each section being constructed
separately from, but rigidly secured to one of the side bars, substantially as set forth.
6. The herein described chain link, it having side bars formed with perforations at
the ends, the thimble formed separately from the side bars and rigidly secured in the
said perforations at the ends, and a pintle adapted to pass through such a thimble
and to be fastened in place, as described.
7. The herein described improvement in the art of making chain links, it consisting
in forming strips or bars to serve as side bars of the links, forming apertures in the
said bar at the ends, cutting tubing into sections, inserting the said tube sections into
the apertures of the said side bars and fastening the said tube sections rigidly in place,
substantially as set forth.
8. The combination with the link, having the side bars formed separately from each
other, the tubular bearing formed separately from and rigidly secured to the said side
bars, of the pintle situated in the said tubular bearing, and the side bars of the
adjacent link rigidly secured to the said pintle, substantially as set forth.
Dated this 1st day of December 1887.
ABEL & IMRAY,
Agents for the Applicant.