AN IMPROVED COUPLING FOR CONNECTING CHAINS, CHAIN CABLES, AND FOR OTHER PURPOSES.
Year: 1883

page_text: LETTERS PATENT to John Henry Vidal at present of Sunderland in the
County of Durham Commander. R.N. for an Invention of "AN IMPROVED
COUPLING FOR CONNECTING CHAINS, CHAIN CABLES, AND FOR OTHER
PURPOSES.'
"
PROVISIONAL SPECIFICATION left by the said John Henry Vidal at the
Office of the Commissioners of Patents on the 2nd February 1883.
JOHN HENRY VIDAL at present of Sunderland in the County of Durham,
Commander R.N. "AN IMPROVED COUPLING FOR CONNECTING CHAINS, CHAIN
CABLES, AND FOR OTHER PURPOSES."
My Invention relates to an improved coupling for connecting chains and chain
cables, and for making fast tackles to sails and spars and for other similar purposes
connected with deck work on board ship, and generally for purposes for which
ordinary shackles are now used.
The advantages of my improved coupling are, strength, simplicity of construction,
and perfect security against becoming accidentally disengaged by shaking about or
otherwise, combined with facility of being attached and detached quickly without
the use of any tools, and perfect immunity from being set fast by rust as is
frequently the case with ordinary shackles. Moreover the coupling is so designed
that it can be exchanged for the existing shackle in any chain cable now in use,
and may be made to conform sufficiently near to the other links of the chain in
size and shape to permit of its fitting the recesses made to receive the links of the
chain in the barrels of steam capstans and other machinery.
The coupling consists essentially of a pair of hook shaped members or half links
provided at one end, which I will distinguish as the heel, with a closed eye through
which passes an ordinary round or oval closed link, hereafter called the joint link,
the two hooks being thus connected to the same joint link. Their heel ends are
side by side and preferably rebated so as to be halved together at the heel ends to
enable their hooks to lie in the same plane or nearly so. The openings of the two
hooks or members face in opposite directions and the hooked end of the one
member fits within that of the other so that when thus closed upon a link of a
Dinn 11

page_text: chain, the strain will be borne by both. The inner hook has a small pin or horn
projecting from the bend at its end which is received in a corresponding hole in the
bend of the outer hook, this pin or horn being of sufficient length, and the eyes at
the heel end of the members, although perfectly loose, yet fitting with sufficient
closeness to the joint link to prevent the hooks or members becoming disengaged
except when brought into such a position with regard to one another and to the
joint link as it is impossible for them to be caused to assume under any
circumstances of their use.
The horn or pin may or may not project quite through and beyond the bend of
the larger hook, and it may itself have a hole in its projecting end through which
may be passed for greater security a small safety or locking ring to form a stop,
this ring being an open ring sprung into position or otherwise secured. Generally
two such pairs of hooks would be so connected to or pivoted upon the same joint
link to form a complete independent coupling for connecting two chains or tackles,
but one pair of hooks only may be used supposing the joint link to be permanently
attached to a chain.
To uncouple the hooks, they must be separated first at the heel ends until the
horn or pin on the one can be disengaged from the other and this can only be done
by turning the joint link into such a position as to admit of the eyes at the heel
ends being moved apart until they reach, or nearly so, the opposite ends of an oval
joint link, or opposite points of a circular joint link, as the case may be. Similarly
in coupling up, the heel ends must be separated to allow the horn or pin to first
enter its hole in the link, after which the eyes at the heel ends are brought close
together and the safety ring, if any, is then inserted through the horn or pin.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Henry Vidal in the Great Seal Patent Office on the
1st August 1883.
JOHN HENRY VIDAL at present of Sunderland in the County of Durham
Commander R.N. "AN IMPROVED COUPLING FOR CONNECTING CHAINS CHAIN
CABLES AND FOR OTHER PURPOSES
"
My Invention relates to an improved coupling suitable for making fast sails and
spars, and for other similar purposes, for connecting chains and chain cables and
generally for purposes for which ordinary shackles are now used. The coupling
would be especially useful in collieries for attaching the trucks to the ropes or
chains for hauling and for detaching them therefrom.
The principal advantages of this coupling are that it combines perfect security
against accidental disengagement, with the greatest facility for coupling and
uncoupling, and that it cannot possibly set fast by rust.
The coupling consists essentially of a pair of "sister hooks" pivotted side by
side upon an ordinary link, the two hooks when closed facing in opposite directions
and lying in or about the same plane, the one within the other, so as to mutually
close one another. The inner hook is provided with a projecting pin or horn
which fits in a corresponding hole in the outer hook and retains the one link in
place within the other. The parts are so constructed that they cannot become
disengaged except when brought into a position with regard to one another which
it is impossible for them to assume under any circumstances of their use.
Buch pairs of hooks may be pivotted upon the same link to form a complete
coupling for inserting between two chains or tackles, but a single pair of hooks will
be sufficient if the link on which they pivot is attached to a chain or rope as would
usually be the case with tackles.
Two
To uncouple the hooks they must be separated at the heel ends and turned into
different planes to enable the horn or pin on the one to be disengaged from the
other which can only be done by turning the link on which they pivot into a
position which it cannot assume so long as there is any strain on it.
In order that the Invention may be more readily understood I have illustrated
it in the accompanying drawings and will proceed to describe it with reference
thereto.
Figures 1 and 2 represent in side and edge views a light form of coupling for
general use such as for making fast tackles to sails and spars on board a yacht for
example. In these figures the coupling is represented closed. Figure 3 shows the
same coupling in the act of being opened. Figure 4 represents the form of the
coupling for connecting chain cables and such like heavy work. In this figure
the coupling is represented as double, whilst in the preceding figures it is shewn
single.
A B are the two hooks or hook shaped members composing the coupling. They
fit the one within the other as shown when in the closed position. Each is formed
with an eye C at the heel end, and through the eye of each passes the same link D
which is a common oval, round, or shackle shaped link, this link forming the joint
pin as it were upon which the two hooks A B are pivotted. The hooks are halved
together at the heel end, that is to say, the eyes C are made only of about half the
thickness of the rest of the books so that when in the closed position the hooks lie
in the same plane and the hook portion of the coupling is of approximately uniform
width looked at edgewise as in Figure 2. E is a small pin or horn projecting
from the bend of the inner hook B and received in a corresponding hole through

page_text: the hook A, whereby the one hook is securely retained within the other.
In some cases for greater security this pin might pass quite through the link A, as
in Figure 4, and have a small safety split ring passed through a hole in its
projecting end to lock it in position, but this will rarely be required.
In Figures 1, 2, 3 a wire or other rope or block is intended to be permanently
made fast to the link D.
The construction is the same in Figure 4 as in the preceding figures except that
the hooks are made stronger and the coupling is double, that is to say, there are
two similar pairs of hooks pivotted upon the same link D.
Referring to Figure 3 it will be seen that to open the coupling it is necessary to
first separate considerably the eyes C at the heel ends of the link and at the same
time turn the hook B into a plane almost perpendicular to that of the hook A and
this can only be done by turning up the joint link D into a position which it can
only assume when free from strain. This being done the horn E can now be
withdrawn from the hole in the other hook and the two hooks immediately fall
apart. The closing of the coupling is effected by reversing these operations.
Having described the nature of my Invention and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the herein-
before in part recited Letters Patent is :-
1st A coupling for the purposes specified consisting essentially of a pair of hooks
or hook shaped members pivotted side by side at their heel ends and fitting the one
within the other so as to mutually close one another, and provided with means of
retaining them in this position, substantially as specified.
2nd The combination of a pair of hooks A B fitting one within the other and
mutually closing one another, a link D on which they are pivotted side by side,
and a pin or horn E substantially as shown and described for the purpose
specified.
In witness whereof I the said John Henry Vidal have hereunto set my hand
and seal this Twenty-eighth day of July in the year of our Lord One thousand
eight hundred and eighty three.