Improvements relating to Conduits applicable for combined use as Casings for Electrical Conductors and for Gas Supply, or for either use separately.
Year: 1892

page_text: Date of Application, 12th Apr., 1892
Complete Specification Left, 11th Jan., 1893--Accepted, 11th Feb., 1893
PROVISIONAL SPECIFICATION.
Improvements relating to Conduits applicable for combined use
as Casings for Electrical Conductors and for Gas Supply, or for
either use separately.
I, JOHN ALEXANDER MCMULLEN, of No. 5 Robert Street, Adelphi, in the
County of London, Electrical Engineer, do hereby declare the nature of this
invention to be as follows:-
The conduits intended for the combined purposes of gas and electric lighting or
for either purpose separately consist, according to my invention, of pipes or tubes
of metal or other suitable material. These pipes or tubes are fitted up in the
usual well known manner in which gas piping is fixed, but lengths of cord or wire
or other suitable means are left in their interior by which electrical conductors can
at any time be pulled through them. In order that this may be done without damage to
the conductors, the angles in the piping consist of specially constructed gas-tight
angle pieces having grooved rollers pivotted within them over which the con-
ductors may pass without friction. It is necessary that the electric conductors
used should be very flexible, the two conductors being made up together into a
flexible cord preferably of circular section. Where the system known as the
one wire system" is used, the electric conductor consists of one properly insulated
flexible conductor only, the metal pipe being used as the return conductor. When
the "two wire" system is used, I prefer to employ conductors made up in a con-
centric form, the centre being composed of a strand of numerous fine wires coated
to a sufficient thickness with insulating material, around which the other conductor,
composed of a similar number of fine wires, is stranded, the whole being coated
with a sufficient outer insulating covering.
66
The pipes may, in some instances, be fitted in the manner usually adopted for
gas; that is to say a main may be carried about the building from which branch
pipes can be tapped off to lights where required. When this is the case it is
necessary that a small gas-tight box with removable lid should be placed in an
accessible position at all points where junctions are made between the main and a
branch for the purpose of inserting fuses. Or the point where the branch is
taken from the main may be fitted with a pulley so that, instead of making a joint
there, the branch electric conductors can be drawn through right from the point of
supply to the lamp, the conductors laying in the main pipe side by side with other
conductors going to other branches. The method, however, which I generally
prefer to adopt is to run a main pipe from the source of supply to a place about
central amongst the points where lights are required, and from this distributing
point I run separate small pipes direct to each of the points to be lighted. When
gas is used, a hollow gas-tight box is fitted at the distributing point into which the
main and all distributing pipes are screwed. When electric light is used, the cover
of this box is removed and in its place a distributing fuse board is fitted.
necessary, a building may have several distributing points, each having its main
to the source of supply, or to a common large distributing point. When switches
are used at places other than at the fitting or at the distributing board, the pipe
must run from the latter point to a small gas-tight box with removable lid at the
point where the switch is required and from thence to the fitting.
Where
It is practicable to use the arrangement as herein described for the combined
purposes of gas and electric lighting, care being taken to render gas-tight all
points where conductors enter or leave the tubes, and also to have the pipes of a
size sufficient to admit of their containing the conductors and at the same time to

page_text: allow for the necessary passage of gas. On the other hand it will be found that
the herein described arrangement of running electric light conductors possesses
great advantages even though it is not intended to use the system for gas.
Dated this 12th day of April 1892.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements relating to Conduits applicable for combined use
as Casings for Electrical Conductors and for Gas Supply, or for
either use separately.
I, JOHN ALEXANDER MCMULLEN, of No. 21 Carlton Hill, St. John's Wood,
(formerly of No. 5 Robert Street, Adelphi,) in the County of London, 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 conduits to be used either for conveying gas or as a
casing for electric light conductors.
The annexed drawings illustrate my invention.
Figure 1 is a side elevation of a specially constructed angle piece, Figure 2 is a
sectional view thereof, and Figure 3 is a cross-section through the line a-b.
Figures 4 and 5 show a distributing box and method of arranging connections
hereinafter more particularly referred to.
According to my invention the conduits consist of pipes or tubes of metal or
other suitable material which are fitted up in the usual well-known manner in
which gas piping is fixed but lengths of small cord or wire or other suitable means
are left in their interior by which insulated electrical conductors can at any time
be pulled through them. In order that this may be done without damage to the
conductors the angles in the piping consist of specially constructed gas tight angle
pieces (see Figures 12 and 3) each having a grooved roller, d, pivotted within
them as shewn over which the conductors may pass without friction. Where the
system known as the "one wire" system is used, the electric conductor consists of
one properly insulated conductor only, the metal pipe being used as the return
conductor. When the "two wire system is used two insulated conductors
are drawn through the pipes. These can be two plain conductors drawn in
side by side or may consist of twisted twin conductors or may be made up in
the concentric form.
The pipes may in some instances be fitted in the manner usually adopted for
gas; that is to say a main may be carried about the building from which branch
pipes can be tapped off to lights where required. When this is the case it is
necessary that a small gas-tight box with removable lid should be placed in an
accessible position at all points where junctions are made between a main and a
branch. When conductors are drawn through, fuses are fixed at these points. Or
the point where the branch is taken from the main may be fitted with a pulley so
that instead of making a joint there the branch electric conductors can be drawn
through right from the point of supply to the lamp the conductors laying in the
main pipe side by side with other conductors going to other branches.
The method which, however, I generally prefer to adopt is illustrated in Figures 4
and 5 wherein a main pipe, D, is run from the source of supply to a place about
central amongst the points where lights are required and from this distributing
point I run separate small pipes, E, direct to each of the points to be lighted.
F, is a hollow box fitted at the distributing point and into which the main, D, and
distributing pipes, E, are screwed. G, is a gas-tight cover or lid over the box
secured by screws, H, as shown, or by other suitable means. When electric light
is to be used, the cover or lid, G, is removed, the conductors are drawn through

page_text: the pipes by means of the cords or wires already within them, and are connected
to a fuse board which is secured to the box in lieu of the cover or lid, G.
Where necessary a building may have several distributing points each having its
main to the source of supply or to a common large distributing point.
When switches are used at places other than at the fitting or at the distributing
board, the pipe must run from the latter point to a small gas-tight box with
removable lid at the point where the switch is required and from there to the
fitting.
As will be readily understood it is practicable to use the arrangement as herein-
before described for lighting by gas or, if afterwards found desirable, the pipes can
be used as casings for electric light 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. An angle piece having a roller pivotted therein adapted to prevent damage
to electrical conductors upon their passage therethrough substantially as set forth.
2. The combination of angle pieces such as above described with pipes adapted
for use for conveying gas or for containing electrical conductors substantially as
set forth.
3. In a system of conduits applicable for use as casings for electrical conductors
and for gas supply, the combination of a box, F, adapted to receive as its cover
either a gas-tight lid, G, or a fuse board, with pipes such as, D, and, E, con-
taining either electrical conductors or means for their passage therethrough
substantially as set forth.
Dated this 11th day of January 1893.
A. F. SPOONER,
124, Chancery Lane, W.C., Agent for the Applicant.