An Improved Conduit System for Electric Conductors.
Year: 1892

page_text: Date of Application, 11th Apr., 1892
Complete Specification Left, 11th Jan., 1893-Accepted, 11th Feb., 1893
PROVISIONAL SPECIFICATION.
An Improved Conduit System for Electric Conductors.
I, WILFRID L. SPENCE, of The Elms, Seymour Grove, Manchester, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
My improved conduit system consists essentially of the following parts; (a) an
outer casing or trough of brickwork, cement-concrete, cast as galvanized iron or
other suitable material, this trough is drained through traps in the well known
manner; (b) a series of separate insulators of any suitable design some forms of
which are shown in the drawings, these insulators serve to support in place with an
air insulation: (a), a series of continuous closed non-conducting pipes made of glazed
earthenware or its equivalent. By equivalent I mean a non-conducting substance
which is impervious to moisture and unaffected by continuous immersion in water,
and which can be moulded to the required form.
My improved conduit is intended, primarily, to carry a series of bare copper
conductors forming part of a low tension distributing network, although, of course,
it is equally adapted for the protection of high pressure insulated feeding mains. It
has the following advantages over existing systems :
It is a genuine drawing-in system and is therefore capable of practically indefinite
extension to meet the demands of the district supplied. No more than the necessary
amount of capital need be sunk in copper at any time.
It is not liable to break-down through the flooding of the exterior tube as are all
other bare wire systems.
It is easily and cheaply laid as there are no fittings requiring special work in the
troughing, and, in addition, there are no complicated straining devices required to
maintain the, alignment of the conductors.
I will now describe the arrangement with reference to the drawings:
A cast iron trough of approximately rectangular section is shown in Figure 1.
An insulating bridge of porcelain, glass or other suitable material support three
pipe lines also of rectangular section.
In Figure 2.a circular cast iron pipe is used as the external protection and three
round tubes are shown supported on a suitable bridge.
A concrete conduit may be used, as Figure 3, to protect the non-conducting pipes
which in the particular case shown are suspended through suitable insulators from
transverse rods.. These insulators may be of any of the well known forms, those in
which the iron hook and supporting stirrup are fastened into the body of the insulator
being particularly applicable.
Figure 4 is merely a modification of the foregoing with the pipes supported from
below on separate insulators.
A couple of methods of jointing the lengths of the non-conducting pipes are shown
in Figures 5 and 6. A separate ring for strengthening purposes being inserted in
the former but none in the latter case. Both joints are intended to be run in with
cement. I make, no claim to these joints however.
The
Figures 7 & 8 illustrate one method of preparing a pipe length for tapping
the conductors. A flat or other face is formed on one side and a deep groove
is made in the material of the pipe before firing. Then when a new branch is
required the centre piece is knocked loose by a haminer and removed.
service wire is next attached by clamping, or better by soldering, and the whole
face made tight again by a sort of washer threaded over the cable and cemented
to the pipe flange. This washer or dead-end may take the form of a screw or
taper plug if desired.
Another method, Figure 9, is to break away a complete cylinder from the

page_text: pipe where the joint is required. Then after the connection is made the pipe
is jointed up again by a split ring which takes the place of the part broken
away, the whole being made tight by cementing.
At all points where such service wires are attached I replace the regular
section of troughing by a suitably modified one arranged as a junction box. At
all bends and corners 1 place suitable manholes to facilitate the drawing in or
out of conductors.
Dated this 11th do of Anul 1905
WILFRID L. SPENCE.
COMPLETE SPECIFICATION.
An Improved Conduit System for Electric Conductors.
1, WILFRID L. SPENCE of The Elms, Seymour Grove, Manchester, 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 ascertained in and by
the following statement :--
My improved conduit system consists essentially of the following parts: (a), an
outer casing or trough of brickwork, cement-concrete, earthenware, cast or
galvanized iron or other suitable material, this trough is drained through traps in
the well known manner. () a series of separate insulators of any suitable design,
some forms of which are shown in the drawings, these insulators serve to support in
place with an air insulation. (c), a series of continuous closed non-conducting pipes
made of glazed earthenware or its equivalent. By equivalent I mean a non-
conducting substance which is impervious to moisture and unaffected by long
immersion in water and which can be moulded to the required form.
My improved conduit is intended primarily to carry a series of bare copper
conductors forming part of a low tension distributing network, although of course
it is equally adapted for the protection of high pressure insulated feeding mains.
It has the following advantages over existing systems: It is a genuine drawing-
in system and is therefore capable of practically indefinite extension to meet the
demands of the district supplied.
No more than the necessary amount of capital need be sunk in
given time.
any
copper at
It is not liable to break down through the flooding of the exterior tube as are all
other bare wire systems. It is easily and cheaply laid as there are no fittings
requiring special work in the troughing. And, in addition, there are no complicated
straining devices required to maintain the alignment of the conductors.
I will now describe the arrangement with reference to the drawings left with the
Provisional Specification.
A cast iron trough of approximately rectangular section is shown in Figure 1.
An insulating bridge of porcelain, glass or other suitable material three pipe lines
also of rectangular section. In Figure 2 a circular cast iron pipe is used as the
external protection and three round tubes are shown supported on an appropriate
bridge.
A concrete conduit may be used, as Figure 3, to protect the non-conducting
pipes which in the particular case shown are suspended through suitable
insulators from transverse rods. These insulators may be of any of the well known
forms, those in which the iron hook or supporting stirrup are fastened into the
body of the insulator being particularly applicable. Figure 4 is merely a
modification of the foregoing with the pipes supported from below on separated
insulators.
A couple of methods of jointing the lengths of the non-conducting pipes are
shown in Figures 5 and 6. A separate ring for strengthening purposes being
inserted in the former but none in the latter example. Both joints are intended to
be run in with cement. I make no claim to these joints however. Figures 7 and 8

page_text: A
illustrate one method of preparing a pipe length for tapping the conductors.
flat or other face is formed on one side and a deep groove is made in the material
of the pipe when it is moulded. When a new branch is required the centre piece is
knocked loose by a hammer and removed. The service wire is next attached by
clamping, or better by soldering, and the whole face made tight again by a sort of
washer threaded over the cable and cemented to the pipe flange. This washer or
dead-end may take the form of a screw or taper plug if desired. Another method,
Figure 9, is to break away a complete cylinder from the pipe where the joint is
required. Then after the connection is made the pipe is jointed up again by a
split ring or cylinder which takes the place of the part broken away, the whole
being rendered tight by clamping or cementing. At all points where such service
wires are attached I replace the regular section of troughing by a suitably modified
one arranged as a junction box. At all bends and corners I place suitable manholes
to facilitate the drawing in and out of conductors.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :
1. In a conduit system for the protection of electric conductors the combination
substantially as set forth, that is to say, of an outer casing or trough containing at
intervals suitable insulating distance pieces or bridges which serve to support in
place with an air insulation one or more lines of non-conducting pipes.
2. The particular arrangements described and illustrated with reference to
Figures 1, 2, 3 and 4 of the drawings.
3. In a pipe line used for the protection of electric conductors, the method of
preparing a pipe length for subsequently connecting a branch substantially as
described and illustrated with reference to Figure 7, and 9 of the drawings.
Dated this 10th day of January 1893.
WILFRID L. SPENCE.