Improvements in Apparatus for connecting Electric Mains.
Year: 1899

page_text: Improvements in Apparatus for connecting Electric Mains.
I, JOHN SOMERVILLE HIGHFIELD, of Wolseley Road, St. Helens, Electrical
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention consists in an improved form of connecting box to be used to
connect any two electric mains or cables; it is adapted specially for connecting
to such systems of mains as consist of insulated cable laid in stoneware wood or
other form of troughing & I so arrange the box that the troughing is in no way
disturbed. I may describe my invention specially with reference to a system of
mains consisting of a single insulated cable laid in a U-shaped trough. The
box consists of two parts, a U-shaped part fitting into the trough carrying the
cable & a box with cover screwed to it; the lower U-shaped part has wood,
porcelain or fibre ends pierced to take the cable & divided into two parts to
enable the cable to be easily placed in position in the box. This U-shaped or
lower part is placed under the cable in the trough, the wood or fibre pieces are
fitted in position round the cable to hold it in place, the insulation of a small
length of the cable is removed and a clamp fitted to this part: the clamp con-
sisting of a split collar of brass or copper and a tail piece which screws onto
the collar so as to fasten it by binding it to the cable, the clamp and bare cable are
then taped and the U shaped box is filled with pitch, bitumen or similar com-
position, between the wood or fibre ends. The top box is then screwed to the
lower U-shaped part, the tail piece of the clamp carrying at its end a screw
terminal which projects through a hole in the top box and is insulated from it by
a porcelain or wood washer: or the whole bottom of the box may be of wood or
similar insulator. In the side of the top box is an opening through which the
insulated cable to be connected to the main is passed; the end of the cable is
cleared of insulation and inserted in the screw clamp; the secondary or branch
cable passes through a small box: formed on the side of the top box: through
wood or other insulating washers and this small box is filled in with bituminous
compound so as to make it watertight; the lid of the upper box is finally adjusted.
The U-shaped lower box & the upper box may be lined with insulating material
to provide greater security froni leakage. When a cover is placed over the
cable troughs a portion of this must be removed to allow my connecting box to
be placed in position but the trough itself is not disturbed. When the whole
length of troughing is filled in with bituminous compound a portion of it must
be removed to allow my connecting box to be put in place; when this has been
done fresh compound is run in round the U-shaped lower part.
In some cases I may arrange the box so that the secondary or branch cable is
connected to an intermediate terminal instead of directly on the terminal on
the tail piece of the main cable clamp the two terminals being connected by a
fusible strip or wire. I may also arrange to fit a single upper box to iwo or

page_text: three U-shaped lower parts so as to connect two or three cables through a single
box.
Dated this Thirtieth day of December 1898.
I, JOHN SOMERVILLE HIGHFIELD, of Wolseley Road, St. Helens, Lancashire,
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 consists of a box arranged in three parts the lower U shaped to
lie in a trough in which the cable is laid, a rectangular top box containing
the terminal or connecting piece and a cover to connect to the cable a clamp
of special construction is used so arranged that it can be rapidly connected to
the cable.
My invention may be more particularly described by referring to the drawing
in which the box and clamp are shown in plan section and end section together
with a separate view of the clamp. In the separate view the same letters refer
to the same part. is the lower or U shaped box which is to lie in the trough
in which the cable is laid. e is the cable to which connection is to be made.
bis the clamp which may be made as shown in the end section. This clamp
consists of a U shaped brass or copper strap having projections or ears at its upper
end into which are screwed two or more set screws; these hold in position the
upper brass or copper tail piece on which are formed lugs or ears through
which the set screws are passed; the end of the tail piece next the cable is
slightly grooved so as to more conveniently clamp the cable and the top is fitted
with a screwed stud and a nut or with a set screw which serves to hold in place
a metal wire which may be used to make electrical connection between the tail
piece & the terminal . I prefer in some cases to use the clamp, 'shown in
Figure 4 and which forms part of my invention: this consists in a brass or
copper strap on the ends of which when pressed together is formed a taper
screw, this strap is made sufficiently flexible to allow of its being sprung out at
the screwed end, and placed round the cable to which connection is to be made:
the second part of the clamp consists in a tail piece the lower end of which
is bored out and furnished with a thread to fit the taper thread on the strap d,
the tail piece is screwed up on the taper threaded ends of the strap d, and serves
to press them together and so hold the strap tightly round the cable. The tail
piece is provided with a screwed stud and nut or with a set screw to be used
as described for the first clamp to hold a metal. Wire used to connect electrically
the tail piece and the terminal e. are fibre or wood divisions made in two
parts fitted above and below the cable and after the clamp is put into position
and the hare part of the cable taped up the spaces between g, g, g, g are filled
up with pitch or bitumen compound. The wood or fibre division f is then
placed in position so that the tail piece of the clamp projects into the upper
box a, which is fixed to the lower part by screws, the joint between the two being
made watertight the branch cable which it is desired to attach to the main cable e
is then passed through the gland J and affixed immediately to a special terminal c
which is screwed to the wood or fibre division f the tail piece b and the terminal c
are then connected by a fusible wire or strip held under the nuts and washers

page_text: on top of the terminal e and the tail piece b. The gland J is filled with bitumen
compound through the screw and the cover p finally screwed to the box a.
To provide better insulation and to prevent any possibility of contact with
the lower box & I may put in a fibre liner h.
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. A box consisting of a cover, a rectangular oblong part and a U shaped
lower part arranged so as to conveniently, fit into the troughs in which electric
cables are laid the lower part having a through way through which the cable
passes, a clamp to fasten to the cable and partitions to hold a pitch or bitumen
compound in position as described.
2. A clamp consisting of a tail piece with top terminal and a female taper
screwed end and a clamping piece bent on itself so as to enclose the cable and
arranged with a male taper screw so as to be conveniently held round the cable
by screwing on the tail piece as described.
Dated this Twenty-ninth day of September 1899.