Improvements relating to Conduits for Electric Conductors.
Year: 1897

page_text: Date of Application, 13th July, 1897-Accepted, 4th Sept., 1897
[Communicated from abroad by THE AMERICAN SILEX COMPANY, a corporation
organised under the laws of the State of West Virginia, and having its principal
office at No. 39-41 Cortlandt Street, in the City of New York, State of New York,
United States of America.]
1
Improvements relating to Conduits for Electric Conductors.
I, HENRY EDWARD NEWTON, of the Office for Patents, 6 Bream's Buildings, Chancery
Lane, in the County of London, Patent Agent, do hereby declare the nature of this
invention and in what manner the sameis to be performed, to be particularly described
and ascertained in and by the following statement:—
The invention relates to improvements in conduits for electrical purposes, with the
particular object in view of providing a metallic race-way for the reception of either
bare or insulated wires or conductors, as may be found desirable.
It has been found, by careful experiment, that pure silex possesses, as an insulator,
those qualities which answer the requirements of laws and rules adopted in our great
cities and towns, as a safeguard against fire from electric currents.
With little or no tendency to absorb moisture, a non-conductor of heat, and fusible
only at twelve thousand degrees Fahrenheit, or thereabouts, and at the same time a
perfect non-conductor of electricity, it follows that an electric wire securely embedded
in silex is safely insulated.
In wiring houses, and in running conductors to accommodate the varions demands,
it becomes of great importance that the insulator shall be in the nature of a race-way,
through which the conducting wire may be drawn at pleasure, and the greater the
freedom with which the wire may be drawn, the more desirable the race-way,
provided the insulation be perfect.
The present invention consists, broadly, in a metallic race-way suitably insulated
from surrounding objects, and more specifically in the structure of the pipe or conduit,
and nature of the insulating material for holding one or more of the metallic race-
ways in position to receive the conducting wire or wires.
A practical embodiment of the invention is représented in the accompanying
drawings, in which—
Figure 1 is a view in side elevation, partly in section, of a pipe or conduit with a
plurality of metallic race-ways supported therein.
Figure 2. is a transverse section of the same in the plan of the line 2-2 of
Figure 1.
Figure 3 is a view in side elevation, partly in section, of a pipe or conduit with a
single race-way supported therein; and
Figure 4 is a transverse' section through the same, in the plane of line 4-4 of
Figure 3.
Referring to the structure shewn in Figures 1 and 2, A and A' represent two
consecutive sections of a pipe or conduit within which a plurality of metallic race-
ways in the present instance, three metallic race-ways, denoted respectively by B, B¹
and B2, are supported and insulated from one another, and from the wall of the pipe,
ór conduit, by a packing of finely sub-divided or powdered silex, denoted by C. The
pipe or conduit sections may be of any suitable length or diameter, as the particular

page_text: purpose for which they are used may demand, and may be made of any suitable
material, such, for example, as iron. For purposes of connecting them to form a
continuous conduit, it is found convenient to provide their adjacent ends, the one
with a right-hand screw thread a, and the other with a left-hand screw thread a',
adapted to register with the interior screw thread on a coupling nut D, by the
rotation of which the ends of the conduit sections may be drawn into close contact.
The metallic race-ways B, B1, B2, may be of any suitable size, to accommodate the
conductor to be drawn through them, and may consist of brass or other suitable
metal, preferably a metal which is capable of being bent without liability of breaking
to accommodate the manipulation of the pipe or conduit within which they are
located, when the said pipe or conduit is utilized in connection with wiring a house,
or in other position where it is desirable to bend it at various angles.
The race-ways are, in practice, made in sections of lengths substantially correspond-
ing to the lengths of the sections of the pipe or conduit within which they are
located, and are packed at suitable distances apart from one another, and apart
from the interior wall of the pipe or conduit, by means of the powdered silex.
At the ends of the adjacent sections of the conduit, are provided wads or stops of
mica, denoted in Figure 1 by E and E¹, the said wads of mica being crowded snugly
around the ends of the race ways, and between the race-ways and the interior walls of
the conduit, and provided with correspondingly receding and projecting portions at
the adjacent ends of each of the race-ways, for the purpose of breaking joint, and
causing the adjacent faces of the wads to tightly impinge against each other, when
the ends of the conduit sections are forced toward each other. In the present instance,
I have shewn receding portions in the face of the wad E, such portions being denoted
by e, and correspondingly projecting portions on the face of the wad E¹, said projecting
portions being denoted by e¹. The race-ways in the section A terminate at the
bottom of the recesses e, and those in the conduit section A' at the tops of the pro-
jections el, so that when the conduit sections are brought together, the race-way
sections will have their ends in proximity to each other, it being immaterial whether
they actually contact or not.
To further break joint, and prevent any possible entrance of water to the interior
of the conduit, we find it desirable to stop the outer portion of the wad E a little
short of the end of the conduit section, and extend the wad Ea little beyond the end
of its conduit section.
The metallic race-ways B, B¹, and B2, when thus embedded and held in alignment
by the connection of the pipe or conduit sections, may or may not become a part of
the electric conductor, depending upon the following conditions
-
If the conducting wire which passes through them be a bare wire, and the ends of
the race-way sections are in contact, then the metallic race-way becomes a part of the
electric conductor. But if the ends of the race way sections do not contact, then the
race-way sections will, as a matter of course, cease to become a continuous conductor,
as the spaces between their ends must be bridged by the conducting wire alone. If,
on the other hand, the conducting wire which is passed through the race-ways be an
insulated wire, then the race-ways will, of course, form no part of the conductor, but,
in addition to forming a smooth passage way for drawing the electric conductor into
position, they will serve to protect the wire from all harm, and, in the event of any
imperfection in the insulation of the wire, there will be no harm arising from its
contact with the interior wall of the metallic race-way, as it is itself completely and
effectually insulated and guarded from any liability of becoming injured, or rendered
inoperative, by the proximity of heat.
In the form shewn in Figures 3 and 4, a single metallic race-way B³ is located
within a bed of powdered silex C, packed between its exterior wall and the inner wall
of the pipe or conduit sections A2, A3. In this instance, as in that already described,
the pipe sections are drawn together by a nut D, and the adjacent ends of the metallic
race-way B³ are surrounded by wads of mica, denoted by E2, E3, arranged to break
joints with the adjacent ends of the conduit sections.
It is obvious that slight changes might be resorted to, in form and arrangement of

page_text: the several parts, without departing from the spirit and scope of the invention; hence
it is not intended to limit the scope of the invention strictly to the structure herein
shewn and described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed (as communicated to
me from abroad), I declare that what I claim is :-
1. A race-way for the reception of a bare electric wire, the said race-way having an
exposed inner metallic surface, and capable of being bent, in combination with
means for insulating the race-way from surrounding objects, substantially as set
forth.
2. A metallic race-way for the reception of an electric wire, in combination with a
pipe surrounding the said race-way, and an interposed layer of insulating material
between the race-way and pipe, the said insulating material consisting of granules or
particles free to move relatively to one another, to adjust themselves to any bending
of the race-way and pipe, to keep the insulating layer intact, substantially as set
forth.
3. A race-way for the reception of a bare electric wire, the said race-way having
an exposed inner metallic surface, in combination with a pipe surrounding the race-
way and a layer of substantially pure powdered silex packed between the race-way
and surrounding pipe, substantially as set forth.
4. In combination, a plurality of pipe or conduit sections, metallic race-ways for
electric conductors located within said pipe or conduit sections, an insulating packing
intermediate of the race-ways and the interior walis of the conduit sections, wads of
mica located at the adjacent ends of consecutive pipe or conduit sections, and means
for holding the ends of the pipe or conduit sections in close contact, substantially as
set forth.
5. A plurality of pipe or conduit sections, means for insulating electric conductors
from the interior walls of the sections, wads of mica fitted in the ends of adjacent
sections, and provided with corresponding receding and projecting portions on their
adjacent faces, and means for drawing the adjacent faces of the mica wads into close
contact, substantially as set forth.