Improvements in Jointing Electric Cables.
Year: 1898

page_text: Improvements in Jointing Electric Cables.
I, JOHN HENRY BARKER, Electrical Engineer, of 26, Park Parade, Cambridge,
do hereby declare the nature of this invention to be as follows:-
My invention relates to the jointing of concentric cables or house service boxes,
and its object is to enable the longitudinal sections composing the cable to be
separately easily for testing for earth leakage or other purposes.
My invention consists in forming each junction piece, bridging the ends of each
conductor of the concentric cable, in two parts, and bringing up branches from
their meeting ends with suitable insulating material placed between, above the
level of the bitumen or other insulation filling the junction box. I then join
the ends of the branches with suitable detachable connections above the level of
the insulation filling the junction box. These connections are removed when the
section of the cable on either side is to be tested.
In carrying my invention into effect according to one modification say a double
concentric cable, I provide for the outer conductor two quadrantal segments each
fastened at one end in any suitable manner to the corresponding ends of the
conductor. The segments lie in a horizontal plane, and their free ends are pro-
vided with branches which pass up vertically above the level of the insulating
material in which the main joint will be embedded. These branches are insulated
by a strip of vulcanite or such insulation placed between them. The ends of the
branches are joined by plates which may be screwed on. These plates may be
arched so as to pass over the end of the insulating strip which may be allowed
to project so as to prevent arcing across the ends of the branches when the plates
are removed, while the circuit is live.
The inner conductors are joined in a similar manner by two clamps separatel
by an insulating sheet. Branches are taken up from each of these, a strip of
vulcanite separating them from one another. The ends of the two branches are
joined as before described with reference to the branches of the other conductor.
All that requires to be done to separate a section of the cable for testing is to
remove the plates joining the conductor at each end of that section, and this is
very easily done, as the plates are accessible without disturbing the main joint.
To hold the vertical parts of the conductor together securely I may pass insulated
bolts through them, and clamp them thereby to one another, and to their insulating
strip.
MARKS & CLERK,
18, Southampton Buildings, London, W.C., and
13, Temple Street, Birmingham, Agents.

page_text: I, JOHN HENRY BARKER, of 26, Park Parade, Cambridge, 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:-
My invention relates to the jointing of electric cables and its object is to
enable the longitudinal sections composing the cable to be separated easily for
testing for earth leakage or other purposes.
My invention consists in forming each junction piece, bridging the ends of each
conductor of the electric cable, in two parts and bringing up branches from their
meeting ends with suitable insulating material placed between, above the level
of the bitumen or other insulation filling the junction box and in mechanically
securing the branches together. The ends of the branches are joined electrically
with suitable detachable connections above the level of the insulation filling the
junction box. These connections are removed when the section of the cable on
either side is to be tested.
Referring to the accompanying sheets of drawings:-
Figure is a half plan, and
Figure 2 an elevation partly in section of a four way triple concentric junction
box made according to my invention.
Figure 3 shows a plan of a modification of Figures 1 and 2.
Figure 4 is a plan.
Figure 5 a side elevation, and
Figure an end elevation of a pair of jointing devices made according to
my invention.
Figure 7 is a plan.
Figure 8 a side elevation; and
Figure 9 an end elevation of my invention as applied to the jointing of twin
conductors.
In carrying my invention into effect according to one modification, as applied
to a triple concentric cable (see Figures 1 and 2) I provide for the outer conductor
two segments or junction pieces A, each fastened at one end by clamping or other
suitable means to the corresponding ends of the conductors B. The segments or
junction pieces A lie in a horizontal plane, and their free ends are provided with
branches E which pass up vertically above the level of the insulating material
in which the main joint is embedded. These branches E are insulated by a
strip of vulcanite C or other solid insulation placed between them and are
mechanically secured together by insulated bolts. The bolts are omitted
in Figures 1 and 2 but they are similar to those shown at G
in Figures 5, 6, and 7. The ends of the branches E are joined electrically by a
plate D which may be fastened by screws. The plate D may be arched so as to
pass over the end of the insulating strip C which may be allowed to project so
as to prevent arching across the ends of the branches when the plates are removed,
while the circuit is live.
The inner conductors B1 and B2 are joined in a similar manner by two clamps A¹
and A2 respectively, and are separated by insulating sheets C¹ and C. Branches E¹
and E are taken up from each of these, strips of vulcanite C1 and C2 separating
them from one another. The ends of the branches are joined by the
plates D and D2 in ી similar manner to the branches of the other
conductor. The whole junction box F may
level
be filled to a

page_text: below the plates D with bitumen or other suitable insulating material,
or it may be left empty for air insulation. All that requires to be done to separate
a section of the cable for testing is to remove the plates joining the conductor at
each end of that section. This is very easily done, as the plates D 1) and D² are
accessible without disturbing the joints of the clamps to the ends of the con-
ductors.
I may provide instead of the insulating strips C, C1, C2, a single strip or plate C³
of insulating material. This plate C3 will thus be common to the three joints, s
shown in Figure 3. I may provide distance pieces (+ attached to the plate C3
to hold the joints in their proper relative position.
In Figures 4, 5, and 6 are shown a set of divisible clamps for applying to any
conductor as a junction piece. The glands or clamps A are adapted to grip the
ends of the sections of the conductor. From the glands A conducting bars pass
round till their ends almost meet. The meeting ends are provided with vertical
branches E, and are separated by a strip of insulating material C. A plate D
joins the ends E of the conductor. The plate D is fixed by screws. Bolts Gare
provided to bind the vertical branches together, and these are insulated by the
vulcanite sleeves H, and washers L. The holes J are provided for fixing the joint
to the junction box.
Figures 7, 8, and 9 show a method of applying my divisible clamps to a high
tension twin wire cable. In this case I provide clamp pieces A, into which the
conductors B are clamped. From each of these clamp pieces A a vertical
branch E is brought. These vertical branches E are separated by the insulating
strip C which in this case rises above the conductors on each side of it. The
vertical pieces E are joined by a plate D, which is made to clear the end of
the insulating strip C. The plate I) is attached by screws to the pieces E. The
outer conductors B₁ are joined in a similar manner. The insulating strip C is
here made common to the two joints, and serves to hold them, in their proper
relative position, in a similar manner to the plate C3 shown in Figure 3.
The joint is immersed, preferably in bitumen nearly up to the junction
plate D.
Having now particularly described and ascertained the nature of my said inven-
tion. and in what manner the same is to he performed, I declare that what I
claim is:-
1. An electric cable joint having junction pillars such as E, insulated from
but mechanically secured to each other, their ends being electrically connected
by a bridge piece such as D substantially as described.
2. The detachable joints substantially as described with reference to the several
figures of the drawings.
Dated this 9th day of December 1898.