Improvements in the Manufacture of Combined Metallico and Vegetable or Textile Cables or Ropes.
Year: 1896

page_text: Date of Application, 22nd Apr., 1896-Accepted, 6th June, 1896
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Combined Metallico and
Vegetable or Textile Cables or Ropes.
I, REGINALD HADDAN of the Firm of Herbert Haddan aud Co. of 18, Buckingham
Street, Strand, W.C. London, Patent Agent do hereby declare the nature of this
invention a communication to me from abroad by Claude Marie Auguste Gaston
Boucles and the Firm of Boucley, Bardou, Clero and Co. (Corderie Contrale,)
both of Paris, in the Republic of France, Rope Manufacturers, 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 the manufacture of cables or ropes and its purpose is to
improve the manufacture of such as are made of metallic material such as steel
wire, in combination with vegetable generally termed textile material such as homp,
manilla, or equivalent substances so that regard may be bad for the different
degrees to which these materials can or will stretch under tension. The improved
rope is designed to permit tho metallic part of the rope to follow the textile-part
when the latter stretches and yet to bear its share of the strain in the rope
without risk of breaking so long as the limits to which the textile material may
stretch without breaking are not surpassed.
The improved rope may consist of any number of the strands hereinafter described
twisted together in the ordinary way.
Each said strand is composed of a central core of rope yaru a suitable number of
steel or other wires wound helically around the said core but without touching
each other and an outer covering of rope yarn preferably wound spirally around
the metallic part and core aforesaid; this outer covering may be single double or
multiple.
The diameter of the textile core bears such relation to the pitch of the helix of
wire that the rope in stretching under tension causes the coils of the wire belices
first to become separated to a greater distance from each other thus reducing the
diameter of the helices and exercising a lateral compression on the central core,
thus also causing a tension on the wires which then bear their part in the resistance of
the rope. This tension will become stronger in proportion as the cable itself stretches
until a moment will arrive when the wires will commence to stretch this moment
being so timed that during further stretching the limits to which the textile material
and the wires may be stretched without respectively breaking will be reached
simultaneously.
Thus in effect the cable permits each of its component parts to receive and
simultaneously support the same relative strain, thus giving to the improved rope
or cable the same capacity of permanent or elastic stretch that is possessed by
textile ropes with the advantage of greater strength so that the improved ropes are
lighter, more flexible and smaller than textile ropes of the same strength.
In order to further explain the manufacture of our improved cable we have
shown in the annexed drawing in Fig. 1 a cable or bawser with four strands and in
Fig. 2.a cross section thereof Fig. 3 shows a cable obtained by twining together
four hawsers similar to that shown in Fig. 1. In Figs. 1 and 2 it will bo seen that
the improved cables are composed of any number of strands A, twisted together in
the usual manner and each containing a core B, formed of a strand of hemp, manilla
or other convenient textile substance furnished with a cover C of steel wires
D
1

page_text: belically arranged round this coro, but without touching each other in order that
they may approach each other on the compression of the core when the latter
stretches.
Over these metal wires is a second or outer covering D of usual textile materials
which protects the metal and gives to the cable the usual appearance of a rope.
This is made of the same textile as the core and is preferably formed of rope yarn
rolled belically round the metal part. This last covering may be single, double,
or multiple.
The diameter of the core B being properly calculated and made relative to the
pitch of the helix of the wires C, the cable will operate in the following manner.
When the textile material begins to stretch under the effort of traction borne by
the cable the helical disposition of the steel wires allows them to follow without
the metal being stretched and this by their simply closing round the core to form
longer helices than before which consequently diminishes the diameter of these
helices and makes then exercise increasing compression on the textile core, whence
it results that the metallic coils are brought into tension and also bear their share
of the load on the cable. This tension increasing more and more according to the
stretching of the rope, the moment arrives when the steel wire is stretched itself;
if the dimensions of the different parts of the cable are well calculated the textile
core is then near reaching its limit of its resistance to tension; in order that the
core and the metallic part of the rope are submitted to the maximum tension
which they can support without inconvenience it is also the same with the exterior
covering D and for the other two parts because this covering being made in the
same manner as the core must support the same teusion as this. in order to allow of
an equal lengthening.
It is thus seen that all the parts of the rope work always simultaneously and
under the most rational conditions whence it results that the mixed cables of this
system have the advantage of allowing a permanent or elastic lengthening greater
than completely metallic cables besides being much lighter and more flexible than
ropes formed exclusively of hemp, manilla, or any other textile material having
equal resistance.
This capacity of stretching is an important advantage in most applications
because by this lengthening of the cable when it begins to work, the effort to which
it is submitted is transferred only progressively to the body fixed at its extremity
in order that shocks and abrupt effort are avoided; by menus of its elasticity the
cable acts in the same manner during working and at rest, in order to prevent or
weaken in a certain measure the shocks which too abrupt variations might produce
in the effort of traction or in the resistance.
For considerable strain several parallel cables or ropes similar to that in Fig. 1
are used; in this case the total lengthening between the point whence the power
operates and that where the resistance is attached cannot surpass the lengthening
which any one of the hawsers is susceptible of taking. There are however cases
in which for the reasons we have given before it would be useful to have a greater
lengthening than this and it possible to obtain this as follows:-
Instead of using several parallel ropes or cables we use only one cable or rope
obtained by combining together the number of the necessary hawsers. We obtain
thus a rope which having the same force of resistance as the whole of the hawsers
of which it is composed possesses the advantage of having a co-efficient of
lengthening much more considerable than the hawsers themselves: tho capacity of
lengthening being due for the greater part to the state of torsion: to the co-efficient
of stretching of the hawsers themselves is added; the co-efficient of lengthening
due to the torsion of the hawsers together.
Fig. 3 of the annexed drawing shows a rope composed of four hawsers made as
hereinbefore mentioned and each of them being composed of four strands but it
must be well understood that the number of hawsers entering into the composition
of a rope can be varied as desired as also the number of strands composing a hawser
and the direction of twist.

page_text: Having now particularly described and ascertained the nature of this said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1. A cable or rope the strands of which have each a core of toxtile substance
round which are helically twisted at convenient distances apart steel wires covered
by a simple or multiple textile covering essentially in the manner aud, for the
purposes described and set forth.
2. A rope obtained by twisting together several cables or hawsers constructed as
in Claim I for the purposes described and set forth.
R. HADDAN.