Improvements in Underground Conduits for Electric Wires.
Year: 1897

page_text: [Communicated from abroad by EDWARD S. PEROT, of Yonkers, in the County
of Westchester and State of New York, United States of America.]
Improvements in Underground Conduits for Electric Wires.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
45 Southampton Buildings, in the County of Middlesex, 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 :-
The object of my invention is to provide a sectional underground conduit for
containing electric wires, which shall be water-tight when laid, and the successive
lengths of which shall be provided with means for easy and stable articulation.
This will more clearly appear from the following description, and by reference
to the accompanying drawings, in which like letters of reference indicate
corresponding parts.
Figure 1 represents a longitudinal section of an electric wire conduit.
Figure 2 shows, upon a smaller scale, a main or plurality of such conduits.
Figure 3 represents in detail the end rings, detached, by which successive
lengths of conduits are connected.
In making my conduit, I take a sheet of thin metal, preferably iron, and bend
it to form a sbell or cylinder, a, as seen in Figures 1 and 2, and rivet the meeting
or overlapping edges. This cylinder is provided at each end, for the purposes
of stiffening it for further manufacture and for use, and of connecting the successive
lengths, with a cast or rolled ring, of thicker and heavier metal than that of which
the shell a is composed.
It is preferred to provide each length of pipe with a male ring, such as CD at
one end, and a female ring, as E F at the other, although this is not essential.
The form of these rings, is, however, of great importance. As will appear more
clearly in Figures 1 and 3, the male ring CD is provided with a sleeve c, c, of
a diameter to fit snugly in the end of a. The sleeve c is thrust into a until the
end of a abuts against the shoulder d, which is of about the same depth as the
metal of a. In order to secure a firmer union of c and a, I may fasten them
together by rivets, as is shown in Figure 1. The outer end of CD is tapered
off, substantially as is shown at e in Figure 1, so as to form the male member of
a wedge-joint.
The female, or engaging, ring E F is likewise provided with a sleeve which
enters and is firmly fastened in the pipe metal a, and with a shoulder d¹ against
which the pipe metal a abuts. The ring E F is chambered out to receive, and
come into close engagement with, the tapered surface e of the male ring C D.
When a length of shell, a, has been provided with a male ring CD at one
end, and a female ring E F at the other, as I have described, its interior is lined
with cement, preferably pure hydraulic cement, as shown at b. This is so applied
to the interior of the shell, a, and to the interior of the end rings C D and E F,
that it will be a practically continuous lining throughout the conduit, when
successive lengths have been laid, as is shown at A. B, in the central conduit of
the main illustrated in Figure 2. After the hydraulic cement lining B, has
thoroughly dried and hardened, the length of pipe or conduit is ready for use.

page_text: The conduit is laid in a trench or ditch by articulating the male and female
ends, respectively, of successive lengths, surrounded with cement or concrete, as
at G, in Figure 2. Figure 2 represents the preferred method of arranging the
conduits where several are led in the same direction. At the bottom of the ditch
or trench is placed a layer of concrete or cement, G; in this one or more pipes
in the plane of A' (successive lengths being articulated as above described)
are imbedded, being supported upon brackets H. On top of these is another
layer of cement, then other conduits similarly articulated and supported,
and so on.
It is not necessary, however, that the conduits be so arranged, or supported.
When it is desirable to lead but one in any direction, no brackets are necessary;
nor is it essential, although it is desirable, that the conduit or conduits be
surrounded with concrete, cement, or other similar substance, as above described.
It has been found to be desirable to make the conduit in about 8 foot lengths;
such sections are convenient for manufacture, comparatively light, and are easy
to handle and to lay. The cement lining b should be applied to a depth of about
half an inch.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign correspondent, I declare that what I claim is :-
1. A conduit for electric wires each section thereof comprising a metal
shell, a cement lining therefor, and end rings which form the opposite members
of a wedge-joint.
2. In a section of conduit for electric wires, the combination of a sheet metal
shell provided with a cement lining and metal end rings, each of the latter having
a collar securely fitted into the end of the shell and an outer end which forms one
member of a wedge-joint.
3. A connection for successive sections of conduit consisting of a wedge-joint
formed by the entrance of the outer end of a tapered ring connected to one
section into the outer end of a reciprocally chambered ring connected to the
adjacent section.
Dated this 10th day of February 1897.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.