Improvements in and relating to Conduits for Electric Cables.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in and relating to Conduits for Electric Cables.
I, WILLIAM SYKES, of 18, New Bridge Street, Blackfriars, in the County of
London, Civil Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to conduits for electric cables and is made in stoneware
or other suitable material, the conduit for the purpose of seperating the respective
cables is made in one piece with tubes circular in section running longitudinally
through it. The conduit is arranged in triangular form the outer portion of the
tube preferably follows in shape the circular tubes by which the body of the
clay is one uniform thickness this is important to prevent cracking by unequal
contraction of the clays.
To enable the various lengths of the conduits to be attached to each other I
form one end spigot and the other end a socket and the two ends may be securely
attached to each other by means of a frictional joint made with a bituminous
lining cast in the socket and a corresponding lining cast on the spigot, these
bituminous linings are cast on the respective parts by steel dies centred in position
by plugs fitting in the tubes of the socket and spigot respectively these plugs
will insure the die always being placed in the same position so that when the
two lengths of conduit are attached to each other the alignment of the tubes are
secured, this is essential to prevent the cables being damaged during the operation
of being drawn through.
The two parts may be securely attached to each other by a cement joint without
the use of the bitumen.
I, WILLIAM SYKES, of 18, New Bridge Street, Blackfriars, in the County of
London, Civil Engineer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:-
This invention relates to conduits for electric cables and is made in stoneware
or other suitable material, the conduit for the purpose of seperating the respective
cables is made in one piece, with ducts circular in section running longitudinally

page_text: through the conduit. The conduit may be arranged and built up in either oblong
or triangular form.
The said invention further provides for coupling the various lengths of the
said conduits in an efficient manner.
-
In order that the nature of this invention may be clearly understood I will
proceed to explain the same by the aid of the accompanying drawings in which:-
Figs. 1 & 2 show longitudinal sections of a conduit according to this invention.
The method of jointing in Fig. 1, comprises a spigot and socket 2; formed
on the adjacent ends of the conduit each having securely attached thereto by
casting on the spigot 1 and socket, 2 a lining 3 and 4 of suitable impervious
and non-corrodible material (such as hereinafter referred to) the lining 3 on the
spigot 1 is so formed that when pressed home and into the lining 4 in the socket 2
a secure frictional joint is formed.
Fig. 3 shows how the bituminous linings 3 and 4 are formed and attached to
the spigot 1 and the socket 2 by means of steel dies.
In Fig. 3 the steel die 5 is formed with a smooth surface slightly tapered as
shown at 6. I form on the lower part of the die a disc 7 which fits into the ducts
of the conduit so as to centre the die for the purpose of pouring in the com-
position forming the linings 3 and 4.
Fig. 4 shows how the linings are attached to the spigot 1 by means of a steel
die 8 the disc 9 for centreing the die is formed in the manner shown.
Fig. 2 shows a longitudinal section of a conduit with plain spigot 11 and
socket 21 the adjacent ends in this case are securely attached by filling in the
space 31 with Portland cement or other like material, the allignment of the invert
is secured by means of a mandril 4¹ which may be made with suitable wood truly
turned and fitted with a handle 51
Fig. 5 shows a cross section of a three way conduit according to my invention.
Fig. 6 shows a section of two three way conduits built up to form a six way
conduit.
Fig. 7 shows a modification of my conduit applicable to what is known as the
solid system, about one third of the conduit is cut off from the top so as to enable
the cables to be laid in the ducts 10 which are filled up solid with bitumen, the
cover 11 may be cemented on the top of the conduit.
The composition linings may advantageously be made of a composition formed
by boiling together gas tar, pitch, sulphur, and ground limestone in suitable pro-
portions and run into position whilst hot. This composition is a known product,
and in itself forms no part of my present invention.
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 conduit having circular duets with spigot and socket ends fitted respec-
tively with bituminous linings substantially of the shape shown the two faces of
which are in contact when pressed home.
2. A conduit having circular ducts with spigot and socket ends capable of
being jointed with Portland cement and centred with a mandril substantially
as described and shown.
3. A conduit having circular ducts and spigot and socket ends with the top
portion cut off to enable the cables to be laid in the ducts.
Dated this 9th day of December 1898