Improvements in or relating to Submarine Telegraph Cables.
Year: 1895

page_text: Date of Application, 14th Nov., 1895-
Complete Specification Left, 14th Aug., 1896-Accepted, 31st Oct., 1896
PROVISIONAL SPECIFICATION.
Improvements in or relating to Submarine Telegraph Cables.
I, FRANCIS CORNWALL CRAWFORD, of The Indiarubber, Guttapercha, and
Telegraph Works Company Limited, Silvertown, County of Essex, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to submarine telegraph cables, the principal object to be
attained being to prevent the kinking of the wire with its consequent evil effects,
although other advantages are incidentally attained.
In carrying out the invention I take the wiro of any suitable description and
size and I coat it with a tape or equivalent, coated or saturated with rubber in a
soft or sticky condition, the edges of the tape overlapping so as to form a complete
covering for the wire. I then cover the tape with any suitable protective coating
preferably of rubber which can be vulcanized so that the outer coating and the
rubbered tape can be vulcanized together, thus forming a complete protection to
the wire.
One of the effects of thus covering the wire is that as the cable is exceedingly
flexible it can bend very freely and return to its normal position when any temporary
strain is relieved so that a turn instead of developing a kink will spring free.
A cable of this description is suitable for use in connecting a light-ship with the
sbore, and may be employed with a drum pivotted on board a lightship, because of
its resistance to kinking any twist thrown into the cable will automatically relieve
itself by turning the drum.
To enable the attendants to ascertain whether a cable is being twisted I prefer
to make the coating in two sections or of different colours or to colour the parts of
it differently or provide lines, ridges, grooves or equivalent so that it can easily be
seen whether these become twisted or not.
Dated this 14th day of November 1895.
BOULT & WADE,
Agents for the Applicant.
Improvements in or relating to Submarine Telegraph Cables.
J, FRANCIS CORNWALL CRAWFORD, of The Indiarubber, Guttapercha and
Telegraph Works Company Limited, Silvertown, in the County of Essex, Electrical
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 relates to submarine telegraph-cables, the principal objects to be
attained being prevention of the kinking of the wire with its consequent evil effects,
and a visible indication if the cable is twisted.
In the accompanying drawing is illustrated partly in elevation, partly in trans-
verse section, and partly with the different layers removed or opened up, a short
length of cable constructed according to this invention; for the sake of clearness
the drawing is made to a larger scale than that to which the cable is actually
!...1

page_text: constructed. A is a stranded telegraphic conductor of the usual construction
situated centrally in the core B of indiarubber, the latter being wound in the usual
or other convenient manner with tape C which is coated with indiarubber previous
to being wound round the core; thus far the cable is of the usual construction..
In applying this invention thereto, wires D of any suitable description and size
are individually encircled by an adhesive indiarubber tape or equivalent adhesive
winding E, which may, for instance, be of ordinary cotton tape, coated or saturated
with rubber in a soft or sticky condition, the edges of adjacent turns of the tape
overlapping ae at E' so as to form a complete covering for each wire; the wires
thus coated are placed round the core B to form a metallic sheathing for the core B
and conductor A; the whole is encased in an outer layer F, preferably of rubber
which can be vulcanised so that it and the adhesive tape E can be vulcanised
together to form a complete protection for the telegraphic conductor and the
core B.
One of the effects of thius covering the wires with a flexible and elastic material
is that as the cable is exceedingly flexible it can bend very freely, and return to
its normal position when any temporary strain is relieved, so that a turn, instead of
developing a kink, will spring free.
A cable of this description is suitable for use in connecting a light-ship with the
shore, and may be employed with a drum pivotted on board the light-ship to turu
about an axis parallel with its diameter; because of its resistance to kinking any
twist thrown into the cable will automatically relieve itself by turning the
drum.
Preferably the flexible and elastic outer layer F is made with its opposite
sides FF of different materials or colours indicated in the drawing by the
difference in the sectioning of the two parts; or it may be provided with lines,
ridges, grooves, or other distinguishing indication so as to readily show if it
becomes twisted.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. A flexible and elastic telegraph-cable substantially as described.
2. In a telegraph-cable a flexible and elastic layer F for the purpose specified.
3. In a telegraph-cable the combination with the telegraphic conductor of
wires D tapes E and flexible elastic layer F for the purpose described.
4. In the production of a telegraph-cable of the kind specified the employment
of wires D in combination with vulcanisable winding E and layer F substantially
as described.
5. A telegraph-cable made or marked substantially as described to afford a
visible indication upon the occurrence of 'twist.
6. The improved telegraph-cable substantially as described and illustrated in
the accompanying drawing.
Dated this Twelfth day of & naust 1900