Improvements in and relating to Chains and Shackles, and in Methods of Making the same.
Year: 1893

page_text: Date of Application, 8th Sept., 1893
Complete Specification Left, 8th June, 1894-Accepted, 25th Aug., 1894
PROVISIONAL SPECIFICATION.
Improvements in and relating to Chains and Shackles, and in
Methods of Making the same.
I, GRAHAM STEVENSON of 117 Onslow Drive, Dennistoun, Glasgow, Consulting
Engineer, do hereby declare the nature of this invention to be as follows:
This invention relates to certain improvements in the structure of chain links
or shackles and also in the methods of manufacturing the same and it has for its
object to make chains and shackles much stronger and more durable than heretofore
and to cheapen their price.
In carrying out my invention I so form the whole or any number of the links
of a chain that they may each serve the purposes and perform the functions either
of ordinary links or those commonly called "shackle" links, i.e. links composed of
two or more pieces capable of being locked or jointed together.
The improvements mainly relate to the heavier classes of chains, i.e. to such.
chains as are commonly used with differential pulley lifting blocks, cranes, cables,
ships' anchors, and the like, where great strength and durability are desiderata.
The links of such chains, under this invention, whilst resembling some of the
present forms in so far as their purposes and applications are concerned differ very
considerably in the material and mode of manufacture and in other points herein-
after referred to.
I prefer to employ steel in place of iron for the construction of the links, the
respective pieces used being generally and variously of a more highly carbonized
character than it is desirable or possible to use in the present systems of chain
making, as a consequence the strength required at the several points of the link to
resist tensile, bending, and shearing strains can be made greater than in what are
called shackle links or even in welded links as heretofore made.
The bars or rods from which the blanks are cut for forming the links, in place
of being rolled of an uniform cross-section throughout their lengths, as hitherto,
are or may be rolled of such an irregular or changing cross-section that cuttings
from them will be of such a form or configuration that they can be finished by a
simple process of machine stamping instead of, as at present, having to hammer
pieces into shape by hand. By this method of rolling and stamping the production
will be rendered much cheaper and more rapid.
The lines of the joints of the several pieces -forming the link are, preferably,
formed through the end or ends in place of the sides as in ordinary shackle links,
whereby greater strength and cheapness are insured.
Both the side and end pieces are varied alike in their cross and longitudinal
sections and also in the sectional areas of their points which has the effect of
increasing, jointly with the increased carbonisation herein before referred to, the
power of said pieces to resist the various amounts and characters of the strains at
different points. The usual uniformity of section and of carbonisation in existing
links renders them weaker at some and stronger at other points.
The sides of the links are made rectilineal and oval in cross section, except at
the points forming the knees, in virtue of each and both of these conditions the
links can be constructed of a smaller measurement across the outside lines of their
sides, so that more length of chain can be accommodated on winding drums or
barrels than with chains formed as usual, with curved or barrel shaped lines
longitudinally and a round cross section which while requiring more room cannot
be so smoothly and snugly coiled up.
As it is, in some instances, desirable that the links of a chain should be as short

page_text: as possible, the links may be so made and joined together as to bear or butt end to
end against one another with just sufficient clearance left as will permit of the free
bending of the chain over the pulleys or drums on which it works.
In the case of chains driving or driven by sprocketed or pocketed wheels, as in
lifting pulley blocks or wheels of like types, it is of the utmost importance;
(1) that the lengths or pitches of the links should be absolutely uniform; (2) that
the inner edges or parts of the link ends or points of contact of link with link
should have as extensive bearing surfaces as possible in order to ensure durability
and permanency in accurate pitch; (3) that the outer edges or parts of the links
at the knees where they engage with the sprockets or pockets should roll with
them into and out of gear as freely and with as little friction as possible.
It will on a little reflection be seen that the 1st and 2nd features can be readily
attained as each link is, or may be stamped in the same die and that the inner
bearing surfaces of their ends are enlarged in the manner hereinbefore set forth.
The 3rd feature is attained by making the ends and knees of the links rectilinear,
looking in plan at the link, and not curvilinear, as usual.
The links may be constructed by several different methods of operation and in
two or more pieces depending for preference on the dimensions of the links for
each chain and the conditions of the works or establishments engaged in their
manufacture. In some cases it will be necessary in order to gain the maximum
profit to lay down extensive plant, whilst, in other cases, a comparatively small
plant may suffice. For example, in most cases it will be preferable to manufacture
the steel, roll the bars for the links, cut the pieces as the bars come from the rolls
and while the rolling heat is on them, join the pieces into links and link the links
together so as to form chains all in the one factory. Under such conditions it
would be preferable to construct the links of one main, one secondary piece and a
rivet or pin. The main piece would be cut, so as to give the best results, length-
ways to the cross-section of the bar which would be rolled of a suitable cross-
sectional conformation so as to shape the piece and suit it for being stamped
into the complete form. When completely shaped the piece would resemble the
letter the gap or hiatus being somewhat less in width than the central opening
of the link. The end faces of the piece would not be cut plain or straight across
but would be stepped or grooved in a dove-tail fashion and be capable of being
either dove-tailed or locked into each other or of being joined by a male double
dove-tailed key or wedge driven into their dove-tailed female grooves.
The
secondary piece would also, by preference, be cut from bars suitably rolled out for
being stamped into finished form. This piece would also be formed with stepped
or grooved faces to correspond, fit into, and lock with those on the main piece so
as to form a bridge to the gap. To further secure the joints a pin or its equivalent
is or may be passed through the knees adjoining the gap and also through the
bridge piece. The holes for the reception of the pin are, preferably, punched at
the same time as the pieces are stamped. The bridge piece and pin are inserted
by pressing machines which also rivet the pins when the links are being connected
together so as to form the chain. When, however, it is desired to add links to
chains or splice two or more pieces of chain together, at the places of their
employment, the bridge piece and pin are driven home by hand and the pin there-
after rivetted.
To separate a link from a chain it is only necessary to cut one of the rivets and
drive out the pin and bridge piece.
In cases where the conditions and powers of production may be different from
those before set forth the links may be formed in four pieces and two rivets or pins
be used, in this case both ends of the link would be open, two pieces would form
the sides and two the ends and these pieces would be dove-tailed or locked and
rivetted together in the same or similar manner to the link having a single gap or
opening.
If desired the link may be formed in two pieces, each of which forms a side,
and two knees or half ends. These when put together with the knees of the

page_text: different pieces facing each other would form the link, the parts being, as before,
secured by dove-tails or wedges.
If desired the pieces may have half dove-tails or steps which lock into each
other or each side piece may be made with a male projection at one end and a
female opening at the other. The projections, in this case, lock into the openings
when the link is being formed.
Dated this 7th day of September 1893.
H. D. FITZPATRICK.
70, Wellington Street, Glasgow, Agent.
COMPLETE SPECIFICATION.
Improvements in and relating to Chains and Shackles, and in
Methods of Making the same.
I, GRAHAM STEVENSON, of 117 Onslow Drive Dennistoun, Glasgow, Consulting
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 :-
This invention relates to certain improvements in the structure of chain links
or shackles and also in the methods of manufacturing the same and it has for its
object to make chains and shackles much stronger and more durable than heretofore
and to cheapen their price.
In carrying out my invention I so form the whole or any number of the links of
a chain that they may each serve the purpose and perform the functions either of
ordinary links or those commonly called shackle links, i.e. links composed of two
or more pieces capable of being locked or jointed together.
Steel is used in constructing the links, the respective pieces being generally and
variously of a more highly carbonized character than it is desirable or possible to
use in the present systems of chain making, as a consequence the strength required
at the several points of the link to resist tensile, bending and shearing strains can
be made greater than in what are called shackle links or even in welded links as
heretofore made.
The bars or rods from which the blanks are cut for forming the links, in place
of being rolled of an uniform cross section throughout their lengths, as hitherto,
are or may be rolled of such an irregular or changing cross section that cuttings
from them will be of such a form or configuration that they can be finished by a
simple process of machine stamping instead of, as at present, having to hammer
pieces into shape by hand. By this method of rolling and stamping the production
will be rendered inuch cheaper and more rapid...
The lines of the joints of the several pieces forming the link are, preferably,
formed through the end or ends in place of the sides, as in ordinary shackle links,
whereby greater strength and cheapness are insured. Both the side and end pieces
are varied alike in their cross and longitudinal sections and also in the sectional
areas of their points which has the effect of increasing, jointly with the increased
carbonisation herein before referred to, the power of said pieces to resist the various
amounts and characters of the strains at different points. The usual uniformity of
section and of carbonisation in existing links renders them weaker at some and
stronger at other points.
The sides of the links are made rectilineal and oval in cross section, except at
the points forming the knees. In virtue of each and both of these conditions the
links can be constructed of a smaller measurement across the outside lines of their
sides, so that more length of chain can be accommodated on winding drums or barrels
than with chains formed as usual with curved or barrel shaped lines longitudinally
and a round cross section, which, while requiring more room, cannot be so smoothly
and snugly coiled up.

page_text: As it is, in some instances, desirable that the links of a chain should be as short
as possible, the links may be so made and joined together as to bear or butt, end
to end, against one another with just sufficient clearance left as will permit of the
free bending of the chain over the pulleys or drums on which it works..
In the case of chains driving or driven by sprocketed or pocketed wheels, as in
lifting pulley blocks or wheels of like types, it is of the utmost importance,
(1) that the lengths or pitches of the links should be absolutely uniform; (2) that
the inner edges or parts of the link ends or points of contact of link with link
should have as extensive bearing surfaces as possible in order to insure durability
and permanency in accurate pitch; (3) that the outer edges or parts of the links
at the knees where they engage with the sprockets or pockets should roll with them
into and out of gear as freely and with as little friction as possible.
It will, on a little reflection, be seen that the 1st and 2nd features can be readily
attained as each link, is, or may be, stamped in the same die and that the inner
⚫ bearing surfaces of their ends are enlarged in the manner herein before set forth.
The 3rd feature is attained by making the ends and knees of the links rectilinear,
looking in plan at the link, and not curvilinear as usual.
And in order that my said invention may be properly understood I have hereunto
appended an explanatory sheet of drawings, whereon,
Fig. 1 is a plan view to a small scale of a bar.
Fig. 2 is a plan to a small scale of a blank e cut from the end of the bar..
Fig. 3 is a cross section to a small scale, of the blank e.
Fig. 4 is a plan, Fig. 5 a longitudinal section, and Fig. 6 a cross section of the
blank as it appears after being stamped.
Fig. 7 is a plan of the finished link.
Figs. 8, 9, 10, 11 and 12 are views showing the method of making locking keys j
for the links from a rolled bar.
Figs. 13 and 14 show in plan another form of the link.
Fig. 15 is a plan view of a bar from which the link Fig. 14 is made, and Fig. 16
is a plan view, to a small scale, of a blank cut from the bar.
J
1
Figs. 17, 18, 19, 20 and 21 are plan views of different forms of the link.
Figs. 18 and 194 are detail views.
Fig. 22 is a perspective view of the bar from which the keying wedges used for
the link Fig. 19 are cut.
Fig. 23 shows a chain composed of alternate solid links and keyed links the latter
being the same as the link at Fig. 7.
. On the drawings the same reference letters wherever repeated indicate the same
or similar parts.
- The links may be constructed by several different methods of operation and in
two or more pieces depending for preference on the dimensions of the links for each
chain and the conditions of the works or establishments engaged in their manufacture.
In some cases it will be necessary, in order to gain the maximum profit, to lay
down extensive plant, whilst, in other cases, a comparatively small plant may
suffice. For example, in most cases it will be preferable to manufacture the steel,
roll the bars for the links, cut the pieces as the bars coine from the rolls and while
the rolling heat is on them, join the pieces into links and link the links together so
as to form the chains all in the one factory. Under such conditions it would be
preferable to construct the liuks of one main piece a, one secondary piece b, and a
rivet or pin c. The main piece would preferably be cut so as to give the best
results lengthways to the cross-section of the bar which would, preferably, be
rolled of a suitable cross-sectional conformation so as to shape the piece and suit it
for being stamped into the complete form.
In manufacturing the link Figs. 4 to 7, a long flat bar d (Fig. 1) of the cross
section shown at Fig. 3 is fed into a suitable stamping and cutting machine, and, at
one operation, the blanke is cut off from the end of the bar and is punched with a
hole. The blank is then inserted in a suitable stamping press which cuts out
the gap or hiatus 9, as shown at Fig. 4 and forms the sides and ends of the link

page_text: to the proper shape. The end faces of the main piece are not cut straight across
but are stepped or grooved as shown at h, h¹ for the reception of a locking key or
wedge which is formed with corresponding steps j, (Fig. 7).
The main piece a which, as shown at Fig. 4, is of a U shape with a gap g some-
what less in width than the central opening f, is now made into the finished link
(Fig. 7) by inserting the key ; and passing a pine through the knees adjoining the
gap and also through the key or bridge piece. The holes c¹ for the reception of
the pin are preferably punched at the same time as the pieces are stamped.
The key and pin c are inserted by pressing machines which also rivet the pins
when the links are being connected together so as to form the chain. When,
however, it is desired to add links to chains or splice two or more pieces of chain
together, at the places of their employment, the bridge piece and pin are driven
home by hand and the pin thereafter rivetted.
To separate a link from a chain it is only necessary to cut one of the rivets and
drive out the pin and bridge piece.
As will be seen (Figs. 4, 5 and 6) the cross-section of the link varies considerably,
being thick and somewhat elliptical at the ends and comparatively thin and some-
what flattened at the sides, in order to give increased strength at the points of the
link which have the greatest strain and to insure, as far as possible, a sufficient
strength or power throughout the link to resist the various amounts and characters
of the strains at the different points.
Figures 8 to 12 show a method of maring the keys from a rolled bar k. This
bar as shown in side view at Fig. 8 and in section at Fig. 9 is rolled with a convex
upper surface, at kl, a concave lower surface at and with angled projecting
ridges k, k. The bar is placed in a suitable stamping machine and a piece or
blank of the section shown at Fig. 9 and front elevation at Fig. 10 is cut off and
is, preferably, at the same time, rounded into the shape shown in side view at
Fig. 11 so as to fit into the gap of the link blank shown at Fig. 4 and to coincide
with the knees at each side of the gap. The blank is then placed in another
machine and the hole m (Fig. 12) punched in it. If desired the blank may be
shaped and the hole m punched in it at one operation. The ridges k, k* form the
steps,, of the finished key.
The key is now finished and can be inserted into the gap of the link and secured
in place by a pin as herein before described.
Figs. 13 and 14 show a slightly different form of link r having two holes o o¹ and
a central web or bridge piece o³. In this case the blank, Fig. 16, is cut off
the flat bar Fig. 15, and the two holes o, o' punched in it at one operation. The
blank is then placed in a second stamping machine and the gap 9 with its side
steps h, his cut in it and also the sides, ends and cross web of the blank are
founded off in the same manner as with the link blank Fig. 4. The link is
finished by inserting a key ; and passing a pin or rivet through it.
Fig. 17 shows in plan view a keyed link suitable for making chains which are
driven by or which drive sprocketted or pocketed wheels. The only departure in
the construction of the link from the forms hereinbefore described is that its ends
and knees are formed rectilinear, in plan as shown, and not curvilinear. The key
is made and rivetted or pinned in place in the same manner as with the other
links.
In Fig. 18 a link is shown which is formed in two pieces a¹, a³ each of which
forms a side and two knees. These when put together with the knees of the
different pieces facing each other form the link, the parts being, as before, secured
by stepped key pieces ;,; and pins or rivets c. The picces a', a' may be cut off
and formed or shaped from a bar which is rolled of the cross section shown at
Fig. 184.
Fig. 19 shows a link which may be cut and shaped at either one or two operations
direct from a flat bar. The faces of the upper ends are formed or cut with dovetail
grooves m, 7721 (see Fig. 19A) and to finish the link its sides are pressed together
and a dovetail key n (Fig. 19) is forced into the grooves m, m². A pin c may be

page_text: '
passed through the ends and dovetail key and rivetted up. The key may be
inserted by hand if so desired.
Fig. 22 shows a rolled bar from which the dovetail keys are cut. As will be
seen this bar is rolled with two longitudinal grooves, one at the upper side and one
at the lower.
Figs. 20 and 21 show a link which may be formed in three operations. A blank
such as shown at Fig. 2 is first cut off the bar and this blank is then formed into
the shape shown at Fig. 20 with a male projection p on one end or face of the open
jaw and a female dovetail groove p¹ on the other face of the jaw. To finish the
link it is finally put into a third machine which presses the link into the shape
shown at Fig. 21 and at the same time closes it by forcing the projection p into the
groove p'. The alternate links of the chain are of course joined to the link before
it is closed.
If desired the link may be made with a web as indicated in dotted lines at q.
Instead of stamping the link blanks Figs. 4, 19 and 20 out of a flat metal bar
they may be formed from a round bar which is bent and shaped into form at either
one or two operations. The links would in this case be finished in the same manner
as before.
If desired, as shown at Fig. 23, each alternate link may in place of being formed
in two or more pieces be formed in one piece solid and without welding; the other
links being made in two or more pieces as hereinbefore described, thus virtually
constituting a chain of solid and shackle links alternately. In the figure t are the
solid links and t¹ the shackle links.
I am aware that secondary or bridge pieces have heretofore been used in chain
links and shackles and it is to be understood that I make no claim for such
per se.
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
consider novel and desire to claim is :-
1. A chain link or shackle made substantially as hereinbefore described with
reference to Figs. 1 to 7 of the drawings annexed.
2. A chain link or shackle made substantially as hereinbefore described with
reference to Figs. 13 and 14, of the drawings annexed.
°
3. A chain link or shackle made substantially as hereinbefore described with
reference to Fig. 17 of the drawings annexed.
4. A chain link or shackle made substantially as hereinbefore described with
reference to Fig. 18 of the drawings annexed.
5. A chain link or shackle made substantially as herein before described with
reference to Fig. 19 of the drawings annexed.
6. A chain link or shackle made substantially as hereinbefore described with
reference to Figs. 20 and 21 of the drawings annexed.
Dated this 6th day of June 1894.
H. D. FITZPATRICK,
70, Wellington Street, Glasgow, Agent.