Improvements in Electrical Conduits and Means for Connecting Conductors in the same.
Year: 1891

page_text: Date of Application, 6th Aug., 1891
Complete Specification Left, 4th June, 1892-Accepted, 30th July, 1892
PROVISIONAL SPECIFICATION.
Improvements in Electrical Conduits and Means for Connecting
Conductors in the same.
I, JOHN MACINTOSH MACKAY MUNRO of 136 Bothwell Street, Glasgow, North
Britain, Electrical Engineer, do hereby declare the nature of this invention to be
as follows:-
This invention relates to improvements in conduits and conductors for the
distribution of electricity underground. The conduits are preferably pipes of fire-
clay or similar material of suitable strength and glaze. Drawing-in boxes are
provided at suitable distances usually about 150 feet apart. These boxes may be
made of fireclay brick and cement or iron or other material. Within the fireclay
pipe are placed insulating discs or supports preferably of earthenware having holes
or grooves to carry the conductors. The conductors are drawn through or into the
holes or grooves in the insulating discs and terminate in the drawing-in boxes.
The conductor in one length of the fireclay pipe is connected with the corresponding
conductor in the succeeding length of the fireclay pipe by means of tightening-up
arrangement made as follows:--
Two bolts are attached one to each conductor.
These bolts are connected,
together by a spiral spring having nuts and swivels so that they may draw the
conductor in each tube tight so that it may be fairly straight within the conduit.
The current may pass from one conductor to the other through the spring, but it
is better to insulate the bolts from the conductors and bridge the conductors
together by means of a separate wire.
Dated this 5th day of August 1891.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.
COMPLETE SPECIFICATION.
1
Improvements in Electrical Conduits and Means for Connecting
Conductors in the same.
1, JOHN MACINTOSH MACKAY MUNRO, of 136 Bothwell Street, Glasgow North
Britain, 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 ascer-
tained in and by the following statement :-
My invention relates to improvements in conduits and conductors for the
distribution of electricity underground.
In order that my invention may be properly understood and readily carried into
effect I have hereunto appended two explanatory sheets of drawings in the several
figures of which corresponding parts are marked with the same letters of reference.
Figure 1 is a view of the drawing-in boxes and pipes.
Figure 2 is an enlarged section of a drawing-in box, shewing straining arrange-
ments for conductors.
Figure 3 is an enlarged section of pipe showing three conductors, which may be
the three conductors of a three wire system of distribution, or if preferred, conductors
of different potential may be placed in separate pipes.
Figure 4 is an enlarged view of Figure 1.
Figure 5 is a cross section of Figure 4.
The conduits A Figs. 1, 3, 4 & 5 are preferably pipes of adamantine fireclay or
similar material of suitable strength and glaze. Drawing-in boxes B Figs. 1 4

page_text: The
and 5 are provided at suitable distances usually about 150 feet apart.
These
boxes B may be made of fireclay brick and cement or iron or other material and
they have an extension downwards B¹ to enable workmen to stand comfortably in
the least possible space while examining or altering the wires. I are the man-
holes. Within the pipe are placed insulating discs Fig. 3 or supports preferably
of earthenware having holes or grooves D to carry the conductors E.
conductors E are drawn through or into the holes or grooves D in the insulating
discs C and terminate in the drawing-in boxes B. The conductor in one length of
the fireclay pipe is connected with the corresponding conductor in the succeeding
length of the pipe by means of tightening-up arrangement shown at Fig. 2 and
made as follows:-Two bolts f, f are attached one to each conductor. These
bolts are connected together by a spiral spring having nuts and swivels, or other
simple means of varying the tension, so that they may draw the conductor in each
tube tight so that it may be fairly straight within the conduit.
The current may
pass from one conductor to the other through the spring, but it is better to bridge
the conductors together by means of a separate wire.
I
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that
what I claim is :-
1. The system of conduits and conductors substantially as described and shown
on the annexed drawings.
2. The use of spring tension arrangement to partially strain the conductors so as
to reduce the number of insulating supports necessary, substantially as described
and shown on the annexed drawings.
3. Joint or drawing-in boxes having manholes at the side of the line of conductors
with extension downwards to enable workmen to stand comfortably in the least
possible space while examining or altering wires, substantially as described and
shown on the drawings.
Dated this 3rd day of June 1892.
BOTTOMLEY & LIDDLE,
154, St. Vincent Street, Glasgow, Applicant's Agents.