Improvements in the Manufacture of Chains and Apparatus for that Purpose.
Year: 1889

page_text: Date of Application, 21st Feb., 1889
Complete Specification Left, 11th Dec., 1889- Accepted, 1st Feb.,
1890
TRU IONAD
Improvements in the Manufacture of Chains and Apparatus for
that Purpose.
I, ARTHUR GEORGE DUFAUD CRAWSHAY of No. 12 North Street Westminster, in
the County of Middlesex, Engineer, do hereby declare the nature of this invention to
be as follows:-
In chains, as they are usually made, where each link has its two ends welded
together, there is apt to be a failure at the weld, especially when the material
employed is steel.
My invention relates to a construction of chain in such a manner that the strength
of each link is rendered in great measure independent of the weld, and to apparatus
employed in constructing chains in this manner. For this purpose having taken a
bar of suitable section and length with both its ends tapered off on opposite sides, I
coil this barwith several convolutions on a roller, guiding the convolutions by means
of a helically grooved pressing roller so that they are kept apart a distance about
equal to the thickness of a finished link. Each convolution, instead of being truly
helical, has a portion of its length made of quicker pitch than the rest, all
these portions, when the bar is fully coiled, coming into coincidence with the
two ends of the bar. Having taken the coiled bar off the roller on which it was
coiled, I pass a previously finished link on to it in the same manner as a key
is passed on to a split ring, and I then squeeze the convolutions together by
hammering or pressure. Having then heated the blank link thus formed, and if
necessary, flattened it so as to bring it to the desired approximately elliptical form, I,
by hammering or pressure, weld the convolutions together and shape the link to the
desired circular section, using for this purpose suitabledies, which are made so as to deal
with the two halves of the link successively, the previously formed link remaining
engaged in the one half while the dies act on the other. As the section of the blank
link, when it is made from flat bar, is at first approximately square, two sets of dies
may with advantage be employed to shape it, the one set giving it an octagonal
section and the other set finishing it to the circular section.
As link after link is thus made, the last made link in each case is engaged in the
coil of the next, and thus a chain is manufactured in continuous length.
· Dated this 21st day of February 1889.
ABEL & IMKAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Chains and Apparatus for
that Purpose.
*I. ARTHUR GEORGE DUFAUD CRAWSHAY of No. 12 North Street Westminster 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:-
In chains, as they are usually made where each link has its two ends welded
together, there is apt to be a failure at the weld, especially when the material
employed is steel.
My invention relates to a construction of chain in such a manner that the strength
of each link is rendered in great measure independent of the weld, and to apparatus
For this purpose, having taken a bar
employed in constructing chains in this manner.
of suitable section and length with both its ends tapered off or scarfed on opposite sides.

page_text: I coil this bar with several convolutions on a roller, guiding the convolutions by means
of a helically grooved pressing roller so that they are kept apart a distance about
equal to the thickness of a finished link. Each couvolution, instead of being truly
helical, has a portion of its length made of quicker pitch than the rest, all these
portions, when the bar is fully coiled, coming into coincidence with the two ends of
the bar. Having taken the coiled bar off the roller on which it was coiled, I pass a
previously finished link on to it in the same manner as a key is passed on to a split ring,
and I then squeeze the convolutions together by hammering or pressure. Having
then heated the blank link thus formed, and if necessary, flattened it so as to bring it
to the desired approximately elliptical form, I, by hammering or pressure, weld the
convolutions together and shape the link to the desired circular section, using for this
purpose suitable dies, which are made so as to deal with the two halves of the link
successively, the previously formed link remaining engaged in the one half while the
dies act on the other. As the section of the blank link, when it is made from flat
bar, is at first approximately square, two sets of dies may with advantage be employed
to shape it, the one set giving it an octagonal section and the other set finishing it to
the circular section.
As link after link is thus made, the last made link in each case is engaged in the
coil of the next, and thus a chain is manufactured in continuous length.
Figure 1 of the accompanying drawings is a vertical longitudinal section of a
machine such I employ for helically winding the bars constituting links of the chain.
Figure 2 is a front view, and Figure 3 is a plan of the machine. Figure 4 is a side
view and Figure 5 a front view of the helically grooved guide roller shewn separately.
Figure 6 shews the coiled bar as made with its convolutions open. Figure 7 shews it
with the convolutions closed together. Figures 8 to 14 inclusive illustrate tools used
for finishing the links. Figures 8, 9 and 10 being respectively a side view, a plan
and an end view of the bottom or anvil tool. Figures 11 12 and 15 are corresponding
views of the top tool for giving the link octagonal section. Figures 13 14 and 15 are
corresponding views of the top tool for finishing the link to circular section. In
Figures 11 and 13 these tools are shewn inserted.
The machine shewn by Figures 1 to 5 inclusive is arranged to give the links at once
the approximately elliptical form of the finished links. A is the elliptical roller on
which the iron bar is wound. This roller has a projection which enters a recess Y in
the upper roller E, which is also elliptical and has a groove formed, not truly helical,
but with a portion, of quicker pitch in each turn, this forming a set off or joggle in
each convolution of the link in line with the scarfed ends of the bar. J is the prime
moving shaft driven by belt on fast and loose pullies L M or it may be by a winch
handle P. On J are two pinions K and K' sliding on a feather. The larger pinion K
gears with pinion O on shaft B, or K may be slid out of gear with O and the smaller
pinion K¹ may be slid into gear with 01 also on the shaft B on which is keyed the
roller A. The pinion gears with a long pinion G on the upper shaft F on which is
keyed the roller E. The shaft F is held in working position by a stop bar H engaged
in a groove of the shaft, but on disengaging this stop, the shaft can be moved length-
wise by a swivel handle T, the pinion G still remaining in gear with O. The bearings
of the upper shaft F are held down by setting screws on blocks Z interposed between
them and those of the lower shaft J, these blocks being of various thicknesses or made
up of a greater or less number of packing plates to suit different dimensions of bars
acted on by the rollers A and E and different dimensions of these rollers.
The bar to be operated on having its ends tapered off or scarfed on opposite
sides is introduced between the rollers A and E with its end against the projec-
tion on A between which and the recess Y in the upper roller E this end is
clamped. As the rollers revolve, the bar is wound on the lower roller A, guided by
the groove in E to take the shape shewn in Fig. 6. The shaft F is then pulled
forwards pushing the coiled bar off A. When the last link of the chain has been
passed along the convolutions of the coiled bar, as a key is passed on to a split ring,
the coils are closed together as shown in Fig. 7, the section which they form together
being approximately square. The link is then heated and subjected to blows or

page_text: pressure between the tools or swages shewn by Figs. S to 15 inclusive. Part of the
bottom tool Figs. 8 and 9 and the top tool Figs. 11 and 12 serve first to reduce the
link to an octagonal section. The other part of the bottom tool and the top tool
Figs. 13 and 14 reduce the octagonal to circular section. When dealing with certain
qualities of metal at suitable heats, the stage of octagonal forming may be dispensed
with, the circular section being produced at once by the latter set of tools.
Each tool which shapes half of the link has a notch or recess W to receive the
link already made which is engaged with the new link, in a position at right angles
to it.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. The herein described process of manufacturing chains by first coiling a bar of
metal helically with joggles to suit the scarfs of the ends and with the convolutions
separated, then engaging with the coil a link previously made, flattening the coil, and
finally shaping the link by suitable tools or dies.
2. For coiling a bar to form a link in the manner above referred to, the machine
substantially as herein described with reference to Figs. 1 to 5 inclusive.
Dated this 11th day of December 1889.
ABEL & IMRAY,
Agents for the Applicant.