Improvements in or relating to Conductors and Conduits.
Year: 1890

page_text: Date of Application, 3rd June, 1890-Accepted, 5th July, 1890
COMPLETE SPECIFICATION.
Improvements in or relating to Conductors and Conduits.
I, HENRY B. COBB, of Wilmington, County of New Castle, State of Delaware,
United States of America, Manufacturer, 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,. more especially, to the construction and arrangement of a
conduit for subterranean use and the electric conductors for which it is provided. It
may here be mentioned that certain details of my improvement are not necessarily
limited to use with an underground system of electric wires, and that I do not,
therefore, wish to be understood as limiting the same to said particular application.
The details referred to will hereinafter be more particularly pointed out.
The prime object of my invention, in its particular relation to underground purposes,
is to provide a conduit, (meaning thereby not only the containing box or tube but all
of its appurtenances, including the manholes and their contents,) which, after having
once been placed, by burying it in the ground, as along a street, need not thereafter
be disturbed for access to the conductors it contains for tapping or using them; and
whereby even necessity for excavating the ground, to make house-connections, need
then never be required.
Further objects of my invention are to afford means for the ready distribution of
the wires at desired points along the line of the conduit, to avoid the possibility of
the accumulation and flow between manholes of gas, and of the consequent explosion
thereof; and to provide in each manhole means for permitting connection, disconnection
and changing of the circuits for the various purposes of such manipulations.
In the accompanying drawing
Figure 1 is a view in perspective illustrating my improved system
Figure 2 is a partly broken plan view illustrating the conduit-portion proper of the
same, the top of the conduit-box being removed;
Figure 3 is a broken sectional plan view illustrating the manner of looping the
conductors contained in the conduit-box;
Figure 4, a longitudinal sectional view of the coupling-joint;
Figures 5, 6, 7 and 8 are detail views of the coupling;
Figure 3), a sectional view of the coupling in the form adapting it for manhole use,
and illustrating the general construction of the joint by a modified form of that
presented in Figure 4; and
Figures 10 and 11 show further modifications, in sect on, of the coupling-joint.
Following is a description of my improved system in all its details.
A is a manhole, which may, generally speaking, involve any well-known or suitable
construction. In each of four sides of the manhole I provide, preferably countersunk
into its wall, as shown, a plate, B, of insulating material, hard-rubber being considered
most advantageous for my purpose. The plates B are provided with perforations,
sufficiently large to receive the ends of the tubes of insulating material preferably
hard rubber-to contain the conductors. C is the conduit-box, of suitable material,
(preferably wood, though other material, including metal, may be used,) extending
from manhole to manhole. In the drawing but one manhole is shown. This will
suffice for purposes of illustrating, since the manholes are all formed alike, or
substantially alike; and it will be understood that between the intervals (as the
intersections of streets) at which they are provided, the box C extends continuously,
Inside the conduit-box C, which extends between and thus, at its ends, envelops the
openings in the walls containing the plates B, are provided, at suitable intervals,
supports, which are conveniently formed of blocks, preferably of wood, in the
shape of diaphragmns, provided with numerous perforations to correspond with the
037

page_text: plates B. Within the box C are supported, to extend from manhole to manhole;
tubes, D, of insulating material, as shown, to receive conducting wires, the
diaphragms affording the intermediate supporting medium, and the plates B that
for the ends, which extend, by preference, only partway through the perforations in
the said plates, being provided, at their extremities, with means hereinafter described
in detail, for coupling them within the manholes.
The tubes D for the conducting wires, within the conduit C are arranged, with
those designed for trunk-lines, along the central portion of the box, while those to be
tapped at more frequent intervals, and affording the distributing lines, are near the
sides thereof.
At desired intervals (as at each house along the route of the conduit to be supplied
with current) the box is provided in its side or sides with apertures, g, which may
be properly insulated internally as by means of suitable lengths of insulating (hard
rubber) tubing in the form of a sleeve or ferrule, p (see Figure 3). Two such
apertures are provided at each point of distribution, and should be in line with each
other longitudinally of the box C, two such sets of two apertures each being so
provided, one set below the other in the side of the box, as represented in Figure 1.
The tubing between a pair of manholes through which to supply current to points
(houses) along the route, is severed, or terminates, at each set of the apertures q
through which it is desired to lead it, being there looped out, to extend to the point
to which the supply of current is to be directed, or, under circumstances hereinafter
mentioned, merely coupled together, but outside the box C).
In laying the conduit, to avoid disturbing it afterward, and any necessity for
excavating the ground, whenever possible, I loop the line for carrying the particular
kind of current, directly to the desired point, and there couple the ends together by
means of my improved removable and adjustable coupling E. Where this is not
permitted, the line from which the distribution is to take place is looped at its severed
or separated ends through the respective apertures in the side of the box C, and
outside of the latter coupled together by means of my improved coupling E. To protect
these couplings, shields, o (the upper of which in Figure 1 are shown to have portions
removed, to display the couplings E inclosed by them), are secured over them, being
provided with apertures, as shown (to be plugged when not in use) to coincide with
the respective apertures q, and each also with a central aperture for the passage of
the line of an incandescent circuit from the center of a coupling Ę to another similar
line. Of course, where the lines may not be looped in the original placing of the
conduit, directly to the points of distribution, the advantage of subsequently being
able to make the necessary house or analogous connections without street-excavation
is lacking.
When the box C has been laid, I fill it with a suitable material (such as sand, n,)
which thus envelops the lines D permanently supported therein, thereby excluding
air, gas and water from the interior, preventing the accumulation of gas and its
flowing between manholes, with the consequent liability to explosion, and also, by
excluding air and water, preventing at least material rotting of the box C if formed
of wood, or the like, or injury thereto by oxidation if formed of metal. After filling
the box C it should be closed by means of a permanent cover, n¹.
Each aperture q in the box C, or rather the section of tubing, or ferrule, p, therein
(Figure 4), is threaded internally, thereby forming the female portion of the
coupling E. At the adjacent ends of each severed line, D, where it is looped through
apertures 7, in the box C, it is provided at each of its two extremities, which reach
only partway through the apertures, with a head, m, of metal (copper) preferably of
disk-shape, firmly secured to the extremity of the metal conductor. The manner of
securing the head- to the conductor, particularly if the latter be composed of twisted
strands of wire, as shown, is to extend a metal-(copper) ferrule, 1, Figure 6, from
one face of the disk-shaped head m, and from around a central opening therein; and to
slip the ferrule over the twisted conductor sufficiently far to cause the end of the
latter to protrude beyond the face of the head m, which is there provided with a series
of radial grooves (as represented in Figure 5) into each of which a strand of the

page_text: conductor is then bent. With the construction of head m thus described, it may be,
and preferably is, covered by a cap, m², of metal (copper) screwed into place on the
head, and which may, if desired, be plated with non-oxidizable metal, as with gold.
For convenience in illustration I have shown, in most places in the drawing, the
caps m² in use on the heads m, m', so that in such cases the heads proper are not
visible. Wherever the cap m² is shown, however, it will be understood to cover a
head m or m¹.
The conductor in each line D is also provided at each end, which extends into a
manhole, A, with a similar head m, protruding partway through its aperture in the
insulating plate B. each aperture in which is internally threaded, the same as each
ferrule, p, or aperture 2, in the side of the box C, the plate B then practically afford-
ing a ferrule of each internally threaded aperture it contains. Whenever a line D
enters its ferrule, whether in a plate B, in a side of the box C, or elsewhere, it is
secured by means of a nut, k, surrounding it, and the male portion of which screws
into the ferrule, the nut being insulated, or formed of insulating material, such as
hard rubber.
Whenever a line, D, is looped, in the manner described, out of a side of the
box C, at points of distribution where it is not permitted to lead it into the place or
house to be supplied with current, the disconnected ends of the line are coupled
together by means (Figure 10) of a section of insulated wire (preferably wire, i,
inclosed in hard-rubber tubing, ), carrying at each end a head, m¹, formed as a
counterpart of the head m and which may thus be merely the metal disk, or the
capped disk and a nut, k¹, like the nut k, is provided at each end of the insulated
section, as shown, to enter the respective ferrule p (or aperture 1) and thus secure
the coupling section in place with the opposing or contact surfaces of the heads m
and m pressed against each other. This particular apparatus is illustrated at X in
Figure 1.
in
Where a line, D, carrying an incandescent current requires to be looped out of
the box C, connecting means, as shown in Figure 10, are employed until the house-
connection is eventually made, when the means are employed shown in Figure 11,
comprising a section of wire, i, in the insulation and provided at its extremities
with the heads m² and nuts, all, thus far, involving the construction already
described with reference to Figure 10, and applied to the threaded apertures 9 in the
manner explained, but, of course, to those of different lines D, as represented at y
Figures 1 and 3. The coupling means for the incandescent-current line is further
provided, between its extremities, with a metal (copper) T, h, comprising a hollow
head surrounding and in direct contact with the wire i, and extended, as to its shank-
portion, as a solid metal stem, carrying, at its extremity, a head, m, the T, h, being
covered, like the wire i, with insulating material, (preferably hard-rubber tubing).
The stem a passes through the central orifice with which the respective shield o is
shown to be provided; and to lead the line into a house, it is coupled, at the stem,
by an internally threaded ferrule, p, enveloping the head m of the stem, to a length:
of the wire to be led into the house, and having a head m at its end inserted int the
frrule p into contact with the head m on the end of the stem a, the two heads being
secured together by means of nuts and k¹ of insulating material like all the said
nuts employed. It will be noticed that the openings through the nuts widen toward
the ends nearest the heads m and m¹. This permits the introduction around the
tubing within the nuts of a suitable cement f, introduced in a warm fluid state, which
serves to render the joints quite impervious to air and moisture.
Where it is possible to lead a line D to a point along the route of the conduit to
be supplied with current at the time of burying the conduit, this is done to afford the
provision for lighting, etc., analogous to that in the case of the well-known and
common manner of providing facilities for introducing gas and water into houses.
This I do by leading the severed ends of the respective line or lines D, through
metal tubes, g, as shown in Figure 1, into the respective house or houses, the ends
being joined by means of my improved coupling E, constructed like that shown in

page_text: Figure 4, and involving the heads on the separated ends of the wires clamped together
inside the ferrule 7 by means of the nuts.
Inside each manhole A the various lines are connected together from one plate B to
another by coupling means like that illustrated in Figure 9, and involving identically
the same construction as the device illustrated in Figure 10, the only exception, if any,
being that the section of insulated wire may be bent to convenient angles.
My improved coupling means thus described is not limited in its use to under-
ground systems, but is intended to be included in my claim for all connecting
purposes to which it is applicable in electric circuits.
But one manner of securing the terminal heads m and m¹ to their respective
conducting wires is herein definitely described. I do not, however, wish to be
understood as limiting my improvement to any particular manner of securing them.
Nor do I wish to be understood, in any sense, as limiting my improvement to the
various details of construction involved therein, as herein shown and described, since
they may be variously modified without thereby departing from the spirit of my
invention. The lines D (comprising wires inclosed in the hard-rubber tubes) in the
box C, to cite one instance of variation, may, or some of them may be coated or
covered with metal, especially those for telephone and telegraph currents.
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 an electric underground system, the combination of a conduit-box extending
between manholes, and having any desired number of tubes of hard insulating
material supported within it and extending from manhole to manhole, substantially as
described.
2 In an electric underground system, the combination of a conduit-box extending
between manholes and having supported within it any desired number of tubes of
insulating material extending from manhole to manhole, and loops extending at
desired intervals from the tubes through the conduit-box for distribution along its
route, substantially as described.
3-In an electric underground system, the combination of a conduit-box extending
between manholes, any desired number of insulated conductors extending from
manhole to manhole inside the said conduit-box, permanently insulated loops
extending at desired intervals from the insulated wires through the conduit for
distribution along its route, and removably adjustable couplings for the said loops
outside the said conduit-box, substantially as described.
4-In an electric underground system, the combination of a conduit-box, C.
extending between manholes and having supported within it any desired number
of tubes of insulating material extending from manhole to manhole, and filling, n, of
sand or the like in the conduit-box, substantially as described.
5 In an electric underground system, the combination of manholes, A, each
containing at different sides perforated insulated plates, B, and a conduit-box, G
extending between manholes and having any desired number of tubes of insulating
material extending within it from manhole to manhole with their opposite ends
projecting partway through the perforations in respective adjacent plates B, and
detachable insulators entering the perforations in the plate B from the manholes,
substantially as described.
6 In an electric underground system, the conduit-box C, extending between
manholes and provided at intervals with lateral openings, 9, and having extended
within it from manhole-to-manhole any desired number of tubes of hard insulating
material severed at and extending at adjacent severed extremities into said openings,
and detachable insulators entering the perforations in the plate B from the manholes
substantially as described.
7-In an electric underground system, the combination of manholes, A, each
containing in different sides perforated insulating plates, B, a conduit-box, C,

page_text: provided at intervals with lateral openings, g, and tubes of insulating material extended
within the box from manhole to manhole with their opposite ends projecting partway
through the perforations in respectively adjacent plates, B. said tubes being severed
at points adjacent to openings y in the box and extended into said openings, and
detachable insulators entering the perforations in the plate B from the manholes,
substantially as described.
S-An insulated electric conductor formed in sections having adjacent ends
provided with metallic heads, a threaded insulating ferrule enveloping the said heads,
and nuts made of insulating material engaging with and entering the ferrule at its
opposite ends and holding the heads in contact with each other within it, substantially
as described.
9-An insulated electric conductor formed in sections having adjacent ends provided
with metallic heads; a threaded insulating ferrule enveloping the said heads, nuts
engaging with the ferrule at its opposite ends and holding the heads in contact with :
each other within it, and a cement filling surrounding the insulated conductor within
the nuts, substantially as described.
10 An insulated electric conductor formed in sections, a metal head on a metallie
ferrule secured around the conductor toward each and inside its insulating covering, a
threaded insulating ferrule enveloping the said heads, and nuts engaging with the
ferrule at its opposite ends and holding the heads in contact with each other within it,
substantially as described.
11-An insulated electric conductor formed in sections having adjacent ends
provided with metallic disk-shaped heads covered with metal caps, a threaded
insulating ferrule enveloping the said capped heads and nuts engaging with the
ferrule at its opposite ends and holding the caps in contact with each other, sub-
stantially as described.
12 In an electric underground system, the combination of manholes, A, provided
in different sides with perforated insulating plates, B, and a conduit-box, C, extending
between manholes and supporting within it any desired number of insulated conducting
wires terminating at opposite ends in metallic heads extending into the respectively
adjacent perforated plates, B, and insulated couplings, E, for use in the manholes,
provided at their opposite ends with metallic heads and affording means for connecting,
within the manholes, conductors from different conduits, substantially as and for the
purpose set forth.
13-In an electric underground system, the combination of manholes, A, provided
in different sides with insulating plates, 1, having internally threaded perforations, a
conduit-box, C, extending between manholes and supporting within it any desired
number of insulated conducting-wires terminating at opposite ends in metallic heads
extending into the threaded perforations in the respectively adjacent plates B and
secured therein by nuts, and insulated couplings, E, provided at their opposite ends
with metallic heads, and affording means for connecting, within the manholes,
conductors from different conduits, substantially as and for the purpose set forth.
14 In an electric underground system, the combination of manholes, A, provided
in different sides with insulating plates, B, having internally threaded perforations,
conduit-hoxes, C, extending between manholes and each supporting within it any
desired number of insulated conducting-wires terminating at opposite ends in metallic
heads extending into the threaded perforations in the respectively adjacent plates B,
and a coupling, for use within manholes for connecting wires leading therefrom to
different conduit-boxes, comprising a section of insulated wire provided at opposite
ends with metallic heads to fit into the threaded perforations in plates B, and provided
toward each end with a nut for securing the coupling in the said threaded perforations,
substantially as described.
15 In an electric underground system, the combination of manholes A, a conduit-
box, C, provided at intervals with perforations, q, and extending between manholes,
any desired number of insulated conducting-wires supported in the box C to extend at
opposite ends into the manholes and severed, in desired number, at points adjacent
to the said perforations, metallic heads secured to the said severed ends and extended
•
:

page_text: into the said perforations, and an insulated coupling for each severed conductor.
connecting the said ends together outside the box C, substantially as described.
16-In an electric underground system, the combination of manholes A, a conduit-
box, C, provided at intervals laterally with internally threaded perforations, q, and
extending between manholes, any desired number of insulated conducting wires
supported in the box to extend at opposite ends into the manholes and severed, in
desired number, at points adjacent to the said perforations 7, metallic heads secured to
the said severed ends and extended into the said perforations, nuts for securing the
said headed ends in place and a coupling, E, for the severed wire, having a section of
insulated connecting wire provided at each end with a metal head to fit against the
heads on the ends of the severed conductor, and provided towards opposite ends with
nuts, substantially as described.
17 In an electric underground system, the combination of manholes, A, provided
in different sides with insulating plates, B, having internally threaded perforations,
conduit-boxes, C, provided at intervals, laterally, with internally threaded perforations, 9,
and extending between manholes, any desired number of insulated conducting-wires
supported in said box C, and extending at opposite ends, provided with metallic heads,
into the threaded perforations of plates B, and severed, in desired number, at points
adjacent to the said perforations q, metallic heads secured to the said severed ends and
extended into the said lateral perforations, a coupling for use within thanholes for
connecting wires leading therefrom to different conduit-boxes, comprisi.. a section of
insulated wire provided at opposite ends with metallic heads to fit into threaded
perforations in plates B, and provided toward each end with a nut for securing the
coupling in the said threaded perforations of the plates B, and a coupling for connecting
the said severed wire, having a section of insulated conducting-wire provided at each
end with a metallic head to fit into the perforations against the heads of the severed
conductor, and provided toward opposite ends with nuts, substantially as described.
18 In an underground system, the combination of a conduit-box, C, extending
between manholes and provided at intervals with lateral openings, g, any desired
number of insulated conductors extending from manhole to manhole in the conduit-
box and severed and extending at adjacent severed extremities into the openings g,
removably adjustable couplings, E, connecting the severed ends of conductors outside
the conduit-box at said openings, and shields, o, secured over said openings outside the
conduit-box, substantially as described.
19-In a joint for the severed ends of a conductor formed each with several wires,
the heads m, m³, of conducting material, secured to the adjacent ends of the said
severed wires, and having, each, the central aperture and the radial grooves, to receive
the wires, and means, substantially as described, for bolding the said heads separably
in contact with each other, substantially as set forth.
Dated the 3rd day of June 1890.
W. P. THOMPSON & BOULT,
Agents for the Applicant.