IMPROVEMENTS IN ELASTIC COUPLINGS FOR ROPES CHAINS RODS AND OTHER MEANS OF CONNECTION THAT ARE LIABLE TO STRAIN
Year: 1882

page_text: LETTERS PATENT to John Greenwood of Southend in the County of Essex
for an invention of IMPROVEMENTS IN ELASTIC COUPLINGS FOR ROPES CHAINS
RODS AND OTHER MEANS OF CONNECTION THAT ARE LIABLE TO STRAIN
PROVISIONAL SPECIFICATION left by the said John Greenwood at the
Office of the Commissioners of Patents on the 11th May 1882.
JOHN GREENWOOD of Southend in the County of Essex "IMPROVEMENTS IN
ELASTIC COUPLINGS FOR ROPES, CHAINS RODS AND OTHER MEANS OF CONNECTION
THAT ARE LIABLE TO STRAIN
»
According to my present invention I construct elastic couplings for ropes chains
rods and other means of connection that are liable to strain as follows:-
A tubular stem having an eye or hook or other means of attachment at one end
and open at the other end has longitudinal slots formed along the greater part of
its length on opposite sides, and has inserted into its open end a rod either solid or
tubular which at its inner end has a split key or cotter driven through it, such
key passing through the slots of the tubular stem. Upon this stem I place a spiral
or helical spring, bearing with its one end against the projecting ends of the before
mentioned cotter, while the other end bears against a nut screwed on to the end of
the tubular stem. Thus any tensional strain put upon the coupling causes the rod
to be drawn out of the tubular stem, thereby compressing the spring to a degree
corresponding to the strain, and the amount of this strain may be conveniently
indicated by a scale marked on the tubular stem, along which the cotter slides.
By preference I construct the spring of two separate parts and I employ the
description known as "volute springs," the coils of which slide within each other on
compression.
According to another modification for use where the coupling is required to act
both in tension and compression, the double volute spring, formed in one piece
formed in one piece, has its one end attached to the tubular stem and its other end
to the rod, which in this case is merely carried up the stem so as to guide it.
Thus on tension being applied the spring is extended by the pull on the rod and
on compression being applied it is compressed by the inward thrust of the rod.
This construction may be applied with advantage for connecting rudder heads to
the screw gear for working them, so as to afford the rudder a certain amount of
yielding action under sudden severe strain.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Greenwood in the Great Seal Patent Office on the
10th November 1882.
JOHN GREENWOOD of Southend, in the county of Essex
"IMPROVEMENTS IN
ELASTIC COUPLINGS FOR ROPES, CHAINS, RODS AND OTHER MEANS OF CONNECTION
THAT ARE LIABLE TO STRAIN
"
According to my present invention I construct elastic couplings for ropes
chains rods and other means of connection that are liable to strain as follows:
A tubular stem having an eye or hook or other means of attachment at one end
and open at the other end has longitudinal slots formed along the greater part of
its length on opposite sides, and has inserted into its open end a rod either solid or
tubular which at its inner end has a split key or cotter driven through it, such key
passing through the slots of the tubular stem. Upon this stem I place a spiral or
helical spring, bearing with its one end against the projecting ends of the before
montioned cotter, while the other end bears against a nut screwed on to the end of
the tubular stem. Thus any tensional strain put upon the coupling causes the rod
to be drawn out of the tubular stem, thereby compressing the spring to a degree
corresponding to the strain, and the amount of this strain can be conveniently
indicated by a scale marked on the tubutar stem, along which the cotter slides.
By preference I construct the spring of two separate parts and I employ the
description known as "Volute Springs," the coils of which slide within each other
on compression.
According to another modification for use where the coupling is required to act
both in tension and compression, the double "volute spring" formed in one piece
has its one end attached to the tubular stem and its other end to the rod, which in
this case is merely carried up the stem so as to guide it. Thus on tension being
applied the spring is extended by the pull on the said rod and on compression
being applied it is compressed by the inward thrust of the rod. This construction
may be applied with advantage for connecting rudder heads to the screw gear for
working them, so as to afford the rudder a certain amount of yielding action under
sudden severe strain
DESCRIPTION TO THE DRAWINGS.
Fig 1 shews a side view, Fig: 2 a longitudinal section and Fig 3 a cross
section on line X X of the construction of the first described arrangement of
the improved elastic coupling which I prefer to employ. A is the tubular stem
having an eye A' by which it is attached to the chain or rod, and provided with a
screw nut B at the other end. C is the second stem, which may be either solid or
tubular also having a ring C¹ at its outer end, and which passes into the open end
of A and has at its inner end a split key D passing through it and projecting
through longitudinal slots A2 A2 in A and also through the loose collar E which is
free to slide up and down upon A. Between the nut B and the collar E are
confined the volute springs F F bearing respectively with their small ends against
the flanges of the nut and collar, while they butt with their large ends against the
grooved disc or washer G, sliding loose on A. These springs may either be single
as at Fig: 1 or double as at Fig: 2. where a second pair of springs H His
arranged within F F¹, butting with their small ends against the inner end of the
nut and collar, and with their large ends against inner grooves of the disc G. On
a strain being applied to the chain or rod to which the coupling is attached, the
stem C will be drawn more or less out of A, thereby causing the collar E to slide
up A and to compress the springs to a corresponding extent.

page_text: Fig. 4 shows the second before described modification of the coupling, adapted to
yield both to compression and extension. In this arrangement the entire double
volute spring F is made of one piece, or it may be formed of two parts fixed firmly
together at x, the one small end being fixed either by a cotter as shewn, or
otherwise, to the tubular rod A while the other small end is attached to the rod C
which slides within A. Thus, on the outer ends of A and C being forced together,
the spring F will be compressed, while when a tensional strain is put upon them,
the spring will be extended. Two such couplings are here shown serving as links
for connecting the screened sleeves I I, on the right and left handed screw threads
of the capstan spindle J to the cross head K of a rudder post L, so that when a
sudden severe strain is put upon the rudder, it will be capable of yielding
somewhat in causing the coupling links to be compressed or extended.
Having thus described, the nature of my invention and in what manner the
same is to be performed, I wish it to be understood that I do not limit myself to
the precise arrangements of my improved coupling as shewn on the accompanying
drawings but, I claim :-
First In elastic couplings the combination of the slotted tubular rod or
stein A with the inner rod or stem C, and the spring or springs F confined between
the nut B or its equivalent, fixed to the rod A, and the collar E or its equivalent
fixed to the rod C, arranged and operating substantially as herein described with
reference to figs. 1 2 and 3 of the accompanying drawings
Second-In elastic couplings the combination of the tubular rod or stem A with
the inner rod or stem C and the spring or springs F attached at one end to the
rod A and at the other end to the rod C, arranged and operating substantially as
herein described with reference to Fig 4 of the accompanying drawings:
In Witness Whereof, I the said John Greenwood have hereunto set my
hand and seal this seventh day of November in the year of our Lord, one
thousand, eight hundred and eighty two:
JOHN GREENWOOD (L.S.)