Improvements in Chain Shackles or Couplings.
Year: 1889

page_text: Date of Application, 24th May, 1889-Accepted; 7th Sept., 1889
COMPLETE SPECIFICATION.
Improvements in Chain Shackles or Couplings.
I ROBERT JAMES RAE of 85 Gracechurch Street London 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 refers to the construction of chain shackles, or couplings, similar
in shape to the ordinary links of a chain, and more especially, to the formation of
certain parts of such shackles or couplings, as well as to the method of fastening
them together, in order to increase their strength, and afford ready means of
securing or detaching the chains, while as in the case of certain improvements embraced
in my former Patent No. 17599 dated 3rd December 1888, the form of the shackle
allows it to pass round a windlass barrel, or through a hawse, pipe, and otherwise, as
freely as the rest of the chain, thereby preventing the damage and delays so
frequently caused by shackles as hitherto made.
The Invention is carried out as follows. The body of the shackle is composed of
two parts, each resembling somewhat in form the letter U, and so constructed, that
when joined or drawn together, as shewn in Figs. 7 and 10 of the annexed drawing,
the shape of the shackle externally, is very nearly like that of an ordinary chain link.
The said Figs. 7 and 10 likewise shew an improved method of constructing the
stems and sockets of the shackle, instead of making these parallel with the centre
line of the shackle, as shewn in Figs. 1 and 4, they are formed at a considerable angle
therewith, the object being to reduce thereby, the strain on the keys or fastenings
that serve to hold the two halves of the shackle together.
The shackles are usually intended to be secured or fastened together as shewn
in Figs. 1 and 10, by means of suitably shaped keys which pass through the stems
and sockets of the shackle, and are then drawn firmly into the required position by
circular, or other shaped nuts operating upon screws provided on the ends of the
keys for that purpose, these nuts also serve to form the stud which is used to
prevent the collapse of the shackle, when the latter is subjected to severe lateral
strain.
It is however sometimes preferred to secure the shackle together as shewn in Figs. 4
and 7, and in such case the stems and sockets of the shackle are constructed with
recesses shaped to receive, and fit the ends of a duplex key, capable of being inserted
and turned into its proper position diagonally, and thereby secure the two halves of
the shackle firmly together. The stud or distance block ased in this instance to
prevent the shackle collapsing, may be made in halves as shewn in the drawing, or
otherwise, and being shaped so as to fit closely between the sides of the shackle, as
well as around the duplex key, serves to hold the latter firmly in its place, a bolt and
split pin, or other fastening, is provided to secure the stud or block in its proper
position.
The distance block may, when so preferred, be modified in shape, the sides thereof
being made flat, or with projections or teeth of suitable shape formed thereon as shewn in
Figs. 13 and 14, the other parts of the shackle being in such case shaped so as to
match with, and fit the block. A suitable key fastens all together.
The section of the stems and sockets of the shackle may be of D shape as shewn
in the drawing, or of any other suitable section.
In the accompanying drawings
Fig. 1, is a plan of shackle shewing the method of securing the parts together by
means of the keys a. a. at each side, drawn into the required position and securely
held by the nuts b. b. which also act as a stud for the shackle.
tion of th
1

page_text: Fig. 4 plan of a shackle secured together by the duplex key c which is held in place
by the stud or distance block e.
Fig. 5 side elevation of Fig. 4.
Fig. 6 cross section of Fig. 4 at C. D.
Fig. 7 plan of a shackle shewing the stems f.f. and the corresponding sockets
formed at an angle with the centre line, and secured by means of duplex key c and
stud e as in Fig. 4.
Fig. 8 side elevation of Fig. 7.
Fig. 9 cross section of Fig. 7 at E. F.
Fig. 10 plan of a shackle of like form to Fig. 7, but secured by means of keys a. a.
and nuts b. b. as in Fig. 1.
Fig. 11 side elevation of Fig. 10.
Fig. 12 cross section of Fig. 10 at G. H.
Figs. 13 and 14 plans of shackles shewing modified forms of distance blocks
or studs.
Fig. 15 cross section of Figs. 13 and 14 at T. K. shewing the key, g. which serves
to secure the parts together.
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,
The construction of chain shackles or couplings, the bodies thereof being composed
of two parts formed, and fitted together, as shewn in Figs. 7 and 10, and further-
more securing together the parts of the aforesaid, or other like description of chain
shackles or couplings, either by means of keys with screwed ends, operated and secure
by nuts, which act also as a stud for the shackle, or by means of the, so termed, duplex
keys and their corresponding attachments, or by means of keys and distance blocks or
studs formed and fitted as shewn in Figs. 13 and 14, substantially as hereinbefore
described, and illustrated by the accompanying drawings.
Dated this 24th day of May 1889.