Improvements in or relating to Electric Cables.
Year: 1899

page_text: Date of Application, 23rd Mar., 1899
Complete Specification Left, 20th Dec., 1899-Accepted, 10th Feb., 1900
PROVISIONAL SPECIFICATION.
Improvements in or relating to Electric Cables.
I, ALFRED WHALLEY, of Helsby, near Warrington, in the County of Lancaster,
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to improvements in electric cables, and has special
reference to that class of cable in which the lead covering is protected from
electrolytic or chemical action, it being well-known that such actions often occur
when unprotected lead-covered cables are placed directly in the ground.
Cables made according to this invention are furnished outside the lead covering
with a protective layer of insulating waterproof material in the form of tape,
such for example as a double lapping of unvulcanised mixed rubber. This
taping is preferably placed next to the lead, and underneath the mechanical
protective sheathing, if such is provided.
The following is a description by way of example of one construction of elec-
tric cable according to this invention:-
The copper conductor is insulated with paper, jute or other fibrous material,
which is impregnated with resin oil, bitumen or an insulating wax. This dielec-
tric is protected from moisture by a covering of lead, and the lead in its turn
is guarded from electrolytic or chemical action by two layers of compound rubber
tape. Over the rubber taping is placed a layer of jute, then two steel tapes and
finally more jute, the jute covering being in each case impregnated with an
insulating wax or like material. It is found that the process of impregnating
the jute immediately outside the compound rubber taping with hot wax, softens
the compound rubber sufficiently to make the overlappings of the tape form a
waterproof joint.
A cable such as described may be placed directly in the ground without any
further mechanical protection other than say, a line of bricks placed above the
cable to act as a warning to workmen.
When the cables are to be drawn into pipes it is sufficient to give the water-
proof insulating taping a covering of stout braid or fibrous tape, to protect it
from mechanical injury, whilst it is being drawn into the pipes.
It is to be understood that the insulating, waterproof covering, according to
this invention, need not necessarily be in the form of a rubber composition,
any insulating material, which is also waterproof, and which can be applied as
a tape, may be used.
Dated this 23rd day of March 1899.

page_text: I, ALFRED WHALLEY, of Helsby, near Warrington, in the County of Chester,
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 improvements in electric cables, and has special
reference to that class of cable in which the lead covering is protected from
electrolytic or chemical action, it being well-known that such actions often occur
when unprotected lead-covered cables are placed directly in the ground.
Cables made according to this invention are furnished outside the lead covering
with a protective layer of insulating waterproof material in the form of tape,
such for example as a double lapping of unvulcanised mixed rubber. This
taping is preferably placed next to the lead, and underneath the mechanical
protective sheathing, ff such is provided.
The following is a description by way of example of one construction of elec-
tric cable according to this invention;
-
The copper conductor is insulated with paper, jute or other fibrous material,
which is impregnated with resin oil, bitumen or an insulating wax. This dielec-
tric is protected from moisture by a covering of lead, and the lead in its turn
is guarded from electrolytic or chemical action by two layers of compound rubber
tape. Over the rubber taping is placed a layer of jute, then two steel tapes and
finally more jute, the jute covering being in each case impregnated with an
insulating wax or like material. It is found that the process of impregnating
the jute immediately outside the compound rubber taping with hot wax, softens
the compound rubber sufficiently to make the overlappings of the tape form a
waterproof joint.
A cable such as described may be placed directly in the ground without any
further mechanical protection other than say, a line of bricks placed above the
cable to act as a warning to workmen.
When the cables are to be drawn into pipes it is sufficient to give the water-
proof insulating tape a covering of stout braid or fibrous tape, to protect it
from mechanical injury, whilst it is being drawn into the pipes.
It is to be understood that the insulating, waterproof covering, according to
this invention, need not necessarily be in the form of a rubber composition,
any ronfibrous insulating material, which is also waterproof, and which can be
applied as a tape, may be used.
The accompanying drawing illustrates an electric cable, the lead covering of
which is furnished with a waterproof protective coating according to one con-
struction of this invention.
The cable illustrated is by way of example one of those commonly known as
concentric cables. It comprises inner and outer conductors A and A¹ having
insulation B between them, another layer of insulating material B¹ being placed
between the outer conductor A' and the lead covering C.
Over the lead covering C are placed two layers, D and D', of unvulcanised
rubber tape, wound on in opposite directions. These layers are each put on
ginder tension, and are preferably given what is known as a quarter or a half
overlap." Outside the tapings D and D is placed a layer of jute E, which is
impregnated with hot wax, the heat of the wax causing the layers of rubber D
and Di to soften sufficiently to adhere and form thoroughly waterproof joints.
Over the jute covering E is a protective armouring F, formed of two layers of

page_text: steel tape, and outside this again is a covering of jute G, which may also be
impregnated with wax, or like material.
It is to be understood that the essential feature of this invention is the pro-
tection of the lead covering of an electric cable by a waterproof insulating mate-
rial in the form of tape, and cables furnished with such a protective coating may
be armoured or not as desired.
Although when the protective layer is in the form of an unvulcanised rubber
tape and jute is placed over it it is found that the impregnation of the jute
with hot wax affords a convenient method of rendering the lappings of rubber
tape more adhesive, yet heat may be applied to the protective coating to bring
about this result in any other convenient way.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is:―
1. In an electric cable the combination with the lead covering of a protective
coating of insulating waterproof nonfibrous material in the form of tape for the
purpose described.
2. In an electric cable the combination with the lead covering of one or more
layers of unvulcanised mixed rubber tape forming an insulating waterproof
coating substantially as described.
3. In a lead-covered electric cable a protective coating of unvulcanised mixed
rubber tape the lappings of which are caused to adhere by the application of
heat substantially as described.
4. In an electric cable the combination with the lead covering of a protective
coating of unvulcanised mixed rubber tape with a covering of jute over it the
jute being impregnated with hot wax substantially as and for the
described.
Dated this 18th day of December 1800
purpose
BOULT, WADE & KILBURN,
Agents for the Applicant.