Improvements in Conduits for Wires carrying Electric Current.
Year: 1898

page_text: Date of Application, 23rd Feb., 1898
Complete Specification Left, 26th May, 1898-Accepted, 9th July, 1898
PROVISIONAL SPECIFICATION.
Improvements in Conduits for Wires carrying Electric Current.
We, FRANK GEERE HOWARD, of 10, Berners Street, Oxford Street, London, W.,
Electrical Engineer, and ARTHUR WILLIAM SCLATER, of 182, Oxford Street,
London, W., Electrical Engineer, do hereby declare the nature of this invention
to be as follows:-
Our invention has for object the better protection of insulated wires carrying
electric current than is afforded by the wood casings or compo pipes now commonly
used, whilst providing a conduit through which the wires can be run much more
easily than through the iron or other tubing at present in use. Conduits made
according to our invention, whilst being more effective, are not so costly as the
other methods above mentioned.
The parts of our invention we call for convenience of reference respectively
(1) conduit pieces, (2) cover pieces and (3) angle boxes.
We form straight conduit pieces from strips of rolled sheet metal, preferably
iron, of sufficient width that when the sides hereinafter mentioned have been turned
up, the part between the sides is of sufficient width to take the required number of
wires. We turn up each edge of the length of the sheet or strip of metal at right
angles to the sheet so as to form sides.
We form a cover piece in a similar way by turning up the edges of the length
of another sheet or strip of metal. This cover piece should be of such width that
its sides will fit easily over the sides of the conduit piece.
The depth of the sides of the conduit piece must be sufficient to allow for the
thickness of the wires or cable which our conduit piece and cover are to protect.
The strips of metal used should be at least of sufficient thickness and strength
to resist a nail driven by ordinary hand force.
Although the length of the strips must vary according to the rigidity of the metal
used and the length actually required, we find that 6 feet lengths are most con-
venient as a standard, these being easily cut into shorter lengths if necessary.
By casting or other suitable means we make angle boxes or joints, to be used in
those places where it is desired to change the direction of the wiring, curved or
T shaped as may be required.
The front and sides of these angle boxes are made to project beyond the back of
the box. We refer to the part of the box which will be next the wall or ceiling as
its "back." The amount of this projection must vary according to the size of the
conduit used. The open ends of these angle boxes should be just large enough to
take the ends of the straight conduit piece and allow it to slide up to the edge of
the back of the box.
We attach the angle boxes to the wall by nails or screws passing through flanges
on the angle box.
Having one of these angle boxes fixed in position we push the end of a conduit
piece into it up to the point to which the back has been cut away, so that the edge
of the conduit piece buts against the edge of the back of the angle box. The
conduit piece will then be held firmly in its place on the wall or ceiling.

page_text: The wire may now be run in the conduit piece. As soon as this has been done
the cover piece is placed over the conduit piece and fixed in position by straps to
the wall or other suitable means. The end of the next conduit piece is butted
against that first set up, the wire run in it, its cover placed over it, and the whole
fixed by straps or other means, and so on.
By making the cover pieces slightly different in length to that of the conduit
pieces, the cover piece may be made to assist in holding the (covered) conduit piece
in position, as this prevents the joints of the conduit pieces coming in lines with
the joints of the covers.
The interiors of our conduit pieces, covers, and angle boxes may be coated or lined
with insulating material if desired.
Dated this 23rd day of Tohru 1898
Improvements in Conduits for Wires carrying Electric Current.
We, FRANK GEERE HOWARD, of 10, Berners Street, Oxford Street, London, W.,
Electrical Engineer, and ARTHUR WILLIAM SCLATER, of 182, Oxford Street,
London, W., 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:-
Our invention has for object the better protection of insulated wires carrying
electric current than is afforded by the wood casings or compo pipes now commonly
used, whilst providing a conduit through which the wires can be run much more
easily than through the iron or other tubing at present in use. Conduits made
according to our invention, whilst quite as effective, are not so costly as the other
methods which protect the wires efficiently; and give more ready access to the
wires than is usually the case.
The accompanying drawings, in which like letters represent like parts will help
to explain our invention.
The parts of our invention we call for convenience of reference respectively
'conduit pieces,' C; cover pieces,' D; 'junction' or 'angle boxes,' A; and
terminal' or outlet boxes, T.
We form straight conduit pieces, C, from strips of rolled sheet metal, preferably
iron, or other suitable material, of at least sufficient thickness (from about No. 18
Birmingham wire gauge upwards) and strength to resist a nail driven by ordinary
hand force, and of sufficient width that, when the side, C¹, C, nereinafter
mentioned have been turned up, the part between the sides is of sufficient width
to take the required number of wires. We turn up each edge of the length of
the sheet or strip of metal at right angles to the sheet so as to form the sides, C¹, C¹.
The depth of the sides of the conduit piece must be sufficient to allow for the thick-
ness of the wires, W, W, or cable which our conduit piece and cover are to protect.
We fórm a cover piece, D, in a similar way by turning up the edges of the length
of a corresponding sheet or strip of metal. This cover piece should be of such
width that its sides, D¹, D', will fit easily over the sides, C¹, C¹, of the conduit
piece, as is shown in Figure I. We find that by making the top of the cover
piece more or less curved, as shown in Fig. I, it affords greater protection by more
readily deflecting a nail than when the top is quite flat.
Although the lengths of the strips must vary according to the rigidity of the

page_text: metal used and the length actually required, we find that 6 feet lengths are most
convenient as a standard, these being easily cut into shorter lengths if necessary.
By stamping, casting, or other suitable means we make junction or angle boxes.
to be used in places where it is desired to change the direction of the wiring, curved
or T shaped as may be required.
Referring to that part of the box which (when it is in position) will be next the
wall or ceiling as its 'back,' B; the front, A, and sides of these angle boxes are
made to project beyond the back, B, of the box. The amount of this projection
must vary according to the size of the conduit used. The front, sides, and back
may either be cast or otherwise formed in one piece, or the front may be detachable:
the two parts in the latter case being held together by screwing as at, K, K, or
other suitable means.
Fig. II is a plan of the back of a junction or angle box with its cover, A, on;
Fig. III, the plan of such a box with its cover off.
The ends of these angle boxes should be left open & be just large enough to take
the end of the straight conduit piece, C, and allow it to slide in up to the edge, E,
of the back, B, of the box.
When covers with curved tops are used the inner side of the cover or front of
the angle box should be so fashioned as to fit over the curve.
The inner side of
the front of a terminal box fashioned in this way is shown in Fig. V..
For points where it is desired to bring the wires out, as to a switch or bracket,
we construct a terminal or outlet box in the manner shown in Figs. IV and V.
When it is desirable to continue the conduit past the outlet we leave both ends of
the box open so that the conduit piece (which the sides of the terminal box are
made to take exactly) can run right through, but we provide stops above and
below the outlet so as to prevent the cover pieces from closing it. These stops also
assist to keep the cover pieces in position. Fig. VIII shows a plan of one method
of constructing an outlet box where the conduit is to run through it.
Our angle boxes may also be made with a stop inside the back of the box
instead of cutting away part of its back. Likewise a stop may be placed inside the
front of the box; but in the latter case the conduit and cover pieces must be made
of such dimensions as to pass within the open end of the box. We do not consider
this form as good as that first above described.
We attach the angle boxes and terminal boxes to the wall by nails or screws
passing through the flanges, F, F, of the back of the box or by other suitable
means.
The method of setting up conduits according to our invention is shown in
Fig. VI and is as follows:-We fix an angle box or a terminal box, according as
may be desired, in position. Then we push the edge of the conduit piece, C, up
to the point, E, to which the back of the box has been cut away, so that the edge
of the conduit piece buts against the edge of the back of the angle box or terminal
box as the case may be. The conduit piece will then be firmly held in its place
on the wall or ceiling. The wire, W, W, may now be run in the conduit piece.
As soon as this has been done the cover piece, D, is placed over the conduit piece,
with its end butting against the edges of the front and sides of the angle box, & is
fixed in position by straps, S, or other suitable means. The end of the next conduit
piece is butted against that first set up, the wire run in it, its cover placed over it,
& the whole fixed by straps or other means and so on.
By making the cover pieces slightly different in length to that of the conduit
pieces the cover pieces may be made to assist in holding the (covered) conduit pieces
in position, as this prevents the joints of the conduit pieces coming in lines with
the joints of the covers.
In the accompanying drawings Fig. I shows a conduit piece, C, with its
cover, D, and a strip, S. Figs. II & III have already been described. Fig. IV
shows a plan of the outlet side of a terminal box; Fig. V is a view of a terminal
box; Fig. VI shows a conduit on our system when partly set up; Fig. VII is a
section on the line X Y through the angle box A and shows our form of cover;

page_text: Fig. VIII shows the inside plan of an outlet box such as we use when the conduit
is continued past the outlet, the stops being marked, M.
The interiors of each of the parts of our invention may be coated or lined with
insulating material. Our conduits and covers form a very efficient protection
to the wood casing ordinarily used, & the wood casing in its turn will insulate
our conduits & covers.
Having now particularly described & ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is : —
1. The construction of a system of conduits for wires carrying electric current,
by the use of conduit pieces, cover pieces, junction or angle boxes and terminal
boxes in combination the whole being constructed in the manner substantially
as above described.
2. The construction of a system of conduits for wires carrying electric current,
by the use of conduit pieces, cover pieces and terminal boxes in combination, the
whole being constructed in the manner substantially as above described.
3. The construction of a system of conduits for wires carrying electric current,
by the use of conduit pieces, cover pieces and junction or angle boxes in com-
bination the whole being constructed in the manner substantially as above
described.
4. The construction and use of junction or angle boxes in the manner sub-
stantially as shown in Figs. II, III and VI.
5. The construction and use of outlet boxes (where the conduit is continued
past the outlet) in the manner and for the purposes above described.
6. The construction and use of terminal boxes in the manner and for the pur-
poses above described.
Dotad this 25th day of Mo 1808
FRANK GEERE HOWARD.
ARTHUR WILLIAM SCLATER.