Improvements in Underground Conduits for Electrical Conductors.
Year: 1893

page_text: Date of Application, 16th May, 1893-Accepted, 17th June, 1893
COMPLETE SPECIFICATION.
Improvements in Underground Conduits for Electrical Conductors.
I, JAMES FULTON CUMMINGS, of 26 Howard Street, in the City of Detroit,
County of Wayne and State of Michigan, United States of America, Electrician,
lo 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 :-
This invention relates to new and useful improvements in underground conduits for
electric conductors, and the invention consists in the peculiar method of constructing
the conduit sections and further in the construction of the conduit and the junction
boxes, and further in the peculiar construction, arrangement and combination of
the parts.
In the accompanying drawings,
Fig. 1 is a sectional elevation, showing the manner of constructing the conduit
sections.
Fig. 2 is a sectional view of the conduit section showing the manner of applying
the non-conducting filling.
Fig. 3 is a vertical central longitudinal section through the meeting ends of two
conduit sections, made by my method and connected by a junction box, as in use.
Figs. 4 and 5 are similar sections showing modifications.
Fig. 6 is a cross section through the section, showing a modification of inner
conduit.
Fig. 7 is a section on line xx Fig. 3.
Figs. 8 and 9 are cross sections through the conduit, showing modified forms of
spacing means.
To make my conduit sections, I take two pipes A, B of such size that the pipe B
may be inserted in pipe A and leave an annular space around. In order to maintain
the pipes in proper relation to each other, I employ spacing means, such as a
rope C, wound spirally about the smaller pipe and secured at the ends. This rope
is of a size equal to the annular space between the two pipes, so that when in
In this
position, as shown in Fig. 2, a spiral passage is formed from end to end.
space I force a non-conducting material D and allow it to harden. I preferably
insert at the ends, rings E, which plug the ends of the space between the pipes and
serve to center the pipes.
I have shown in Fig. 2 a pump forcing in the liquid. In place of the rope 1
may employ spacing blocks or strips, as shown in Figs. 8 and 9.
The method thus cousists of centering a smaller pipe in a larger one by spacing
means to leave a continuous space from end to end, filling such space with a liquid
non-conducting material, and then allowing such material to harden.
Instead of using an inner pipe of a single piece I may make it in sections a b, as
shown in Fig. 6, in which case the rope serves to hold the sections of the inner
ducts together. In Fig. 7 I have shown two such sections coupled by a junction
box consisting of two halves G clamped together upon the box, a circular sleeve J
of rubber being interposed between the box and conduit.
In the space between the sleeve and the box, I pour in a non-conducting
compound, as shown at L.
Instead of using the packing sleeve J, other forms of packing may be employed,
as for instance, that shown in Fig. 4, where I show the plug E for the annular
space between the two casings at the ends thereof, and have shown the inner casing
provided with an extension N beyond the end of the outer casing. The ends of
the inner casing are abutted leaving an annular space between the ends of the outer
casing in which I place a suitable insulating ring O of rubber or other material.

page_text: This ring O serves in a measure the purpose of the packing J in the form described.
Around the end of the sections, I clamp the box G and fill in the space within the
coupling as previously described. If desired, for telegraph or telephone conduits,
each section of coupling may be insulated from the other, and this may be
accomplished in any desired manner. I preferably accomplish it by placing an
insulating ring P between the meeting ends of the sections; this ring having
suitable lateral flanges Q on each side overlapping the ends of the outer casing.
The packing sleeve J and filling L outside of this ring prevent possibility of
contact from one section to the other through the medium of the coupling.
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. The herein described method of making underground conducts for electrical
conductors.
2. The herein described underground conduit for electrical conductors.
JAMES FULTON CUMMINGS.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.