Improvements in Spring Cable Tension Devices.
Year: 1897

page_text: Date of Application, 18th June, 1897
Complete Specification Left, 21st Jan., 1898-Accepted, 26th Feb., 1898
Improvements in Spring Cable Tension Devices.
I, ALEXANDER MELVILLE CLARK, of the Firm of A. M. & Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Chartered Institute
of Patent Agents, do hereby declare the nature of this invention (a communica-
tion to me by Thomas Spurr Whitman, of Annapolis, Nova Scotia, Merchant),
to be as follows:-
―:
This invention has particular reference to cables for towing ships and consists
in interposing in such cables, whether chain or wire or otherwise, a spring tension
device which may consist of a series of links of chain interposed somewhere in
the cable, the links of which spring tension are preferably constructed as follows:-
An ordinary link with a flattened perforated end is longitudinally apertured at
the end opposite to the perforated end and through this aperture a headed bolt
passes. Around this headed bolt is a spiral spring which bears against the link
and against a sliding nut or cross-head carried on the bolt. This sliding nut or
cross-head slides in the link and receives the thrust of the spiral spring. The
head of the bolt is apertured so as to be joined to an adjacent link by passing
through the aperture thereof.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
COMPLETE SPECIFICATION.
Improvements in Spring Cable Tension Devices.
I, ALEXANDER MELVILLE CLARK, of the Firm of A. M. & Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Chartered Institute
of Patent Agents, do hereby declare the nature of this invention (a communica-
tion to me by Thomas Spurr Whitman, Merchant, of Annapolis Royal, Nova
Scotia) 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 spring cable tension devices and has for its object to
produce a device specially applicable for towing vessels or serving as ground
tackle for anchoring the same in shoal water.
The accompanying drawing shews a spring tension cable device embodying
the invention. In this drawing Figure 1 is a side view of a section of the spring
tension cable device, and Figure 2 is a section on line 2-2 of Figure 1.
The present invention is mainly directed to producing a device with which
vessels may be towed or anchored with safety. At present it is the custom to

page_text: tow vessels with hemp or manilla hawsers by reason of the fact that the hemp or
manilla hawser having a certain amount of "give" or spring, will lengthen under
strain and contract when the strain is removed, which is a very valuable function
as the strain on the towing or anchoring hawser is always variable by reason of
the lurching of vessels in a seaway. An inherent defect of this method is that
the hawsers require to be quite bulky and likewise are very short-lived as they
become useless when their stretching and contracting qualities have disappeared.
The life of an ordinary towing hawser is about one year during which period all
the stretch has been taken out of it and it is as rigid and inert as a wire cable.
It has been found almost impossible to employ wire cables for towing by reason
of the fact that they do not stretch and consequently break under sudden strains,
the broken end coming aboard and doing considerable damage, frequently sweep-
ing the deck clear of occupants. All these dangers and difficulties are obviated by
the improved apparatus which while constituting a safe towing apparatus, never-
theless enables me to employ wire cables for towing. In order to accomplish
this purpose I interpolate a spring chain cable in a wire towing cable or ground
tackle.
a
The preferred form of the device is shown in Figures 1 and 2 as comprising
series of springy disengageable links. Each of these links is shown as consisting
of a perforated loop a provided with an aperture 6₁ at one end running laterally
therethrough and an aperture 13 at the other end running axially therethrough.
Passing through the aperture c¹³ is a bolt or rod dwhich is shown as provided at
one end with a ring e¹ and at the other end with a cross-head f2, having grooved
or bifurcated ends embracing the side members of the link so as to be guided there
by, the crosshead being secured to the bolt by a pin g². Surrounding the bolt or
rod is a spring which is confined between the crosshead f2 and the opposite
end of the link a¹. Several of these links may be joined together as shown,
ordinarily a sufficient number of joints to make up a length of about six fathoms
called a
shackle," which will be found sufficient for most purposes. It will
be observed that when the cross-head is keyed to the rod or bar d by the pin or
key g, the rod or bar will not turn in the said cross-head, but the cross-head and
bar will be held rigidly together, so that the link so constituted will not in this
instance be a swivelling link but will be a rigid link. A greater or less number of
links may be used, as links may be taken out of the tension device by knocking
out the pin in the cross-head and removing the bolt and spring.
66
When the device is to be employed as ground tackle I preferably attach a section
or shackle" of the spring tension device to the anchor and attach the anchor
chain to the free end thereof, so as to interpolate the said device in the ground
tackle. When employed in a towing device, a section or "shackle
"of the spring
tension device is interpolated in the length of the towing device, that is to say,
the inelastic steel wire cables are rendered elastic by putting the spring tension
cable device therein at intervals. It will be readily understood that by reason
of the great elasticity of the device I can attach the same to the bitts of the towing
vessel and place those bitts as far aft as possible. Heretofore this result has been
unobtainable by reason of the fact that on account of the more or less inelastic
character of the towing device, if the bitts of the towing vessel were placed too
far aft, the lurching of the vessel towed would cause the stern of the towing vessel
to be "yanked around and would render it difficult, if not impossible to steer
her. This difficulty, however, is entirely overcome by reason of the springy
character of the towing device which will take up the strain itself instead of
bringing all the strain suddenly to bear upon the towing vessel.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what I
claim is:-
1. In a device of the character specified, the combination of a cable and a spring
tension device interpolated in its length, the said spring tension device come

page_text: a series of joined links each of which links consists of a plurality of parts engaging
with and movable with respect to each other and having a spiral spring interposed
between the said movable parts.
2. A spring tension link comprising a loop a¹ apertured axially, a bar passing
through the said aperture and into the enclosed portion of the loop, a cross-head
secured rigidly to the bar and provided with bifurcated ends embracing the sides
of the link so as to be guided thereby and a spring surrounding the bar and
interposed between the cross-head and the link, substantially as described and for
the purposes set forth.
3. A spring link comprising a loop a¹ apertured axially, a movable member d
passing through the said aperture and into the enclosed portion of the loop and
a spiral steel spring propelling the movable member into the said loop and press-
ing the said movable member firmly against the inside of the adjacent end of the
loop a when the link is not under tension.
4. In a spring link, the combination of a loop, a bar entering the said loop, a
sliding cross-head engaging the sides of the loop and sliding thereon and having
bifurcated ends embracing the said sides of the loop, the said bar and cross-head
being secured together and a spring interposed between the cross-head and the
inner wall of the loop, substantially as described and for the purposes set forth.
Dated this 21st day of January 1898
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.