Improvements in Conduits for Electrical Conductors.
Year: 1896

page_text: Date of Application, 31st Oct., 1896-Accepted, 5th Dec., 1896
COMPLETE SPECIFICATION.
Improvements in Conduits for Electrical Conductors.
I, ERWIN LAVENS, of 100 Monroe Street, City of Brooklyn County of Kings,
State of New York United States of America, Electrician, 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 this invention is to provide by an improved mode of manufacture,
an efficient conduit for electric conductors which can be produced by unskilled
labor at very small expense, and presents the advantages of an exterior protective
armour, preferably of iron or steel, and an interior lining of insulating material, as
I shall describe referring to the accompanying drawings.
Figure 1 is a side elevation partly in longitudinal section, of a finished piece of
conduit made in accordance with my invention.
and
Figure 2 is a longitudinal section illustrating the process of making the conduit;
Figures 3 and 4 are cross sections taken on the lines x x and y y respectively of
Figure 2.
The improved conduit is made with an inner tubular lining 1, formed of any
soft, pliable and resilient insulating material, and an exterior tubular armour 2, of
protective material, preferably iron or steel, commonly used for similar purpose.
Instead of expanding an interior insulating lining outwards against the inner
wall of a protective armour, as has hitherto been done in various ways, I pass the
insulating lining within an armour tube having an interior diameter slightly larger
than the exterior diameter of the lining, and I then by external pressure, applied in
any approved manner, draw or press the armour tube down closely upon the tubular
lining, thus making a very close and uniform joint between the armour and the
lining.
The drawing or compression may be effected while the armour tube is cold, or
while it is externally heated. When it is cold-drawn the heat generated aids in
effecting a very close union of the armour and lining.
I find that a conduit thus produced when cut at any part of its length shews no
looseness of the joint between the lining and the armour. As the lining cannot
move lengthwise in the armour the conduit is especially adapted for vertical courses
in wiring a building.
In Figure 2, I shew two opposing grooved rollers 3, 4, for compressing or
drawing down the armour upon the insulating lining, the uncompressed portion of
the armour being indicated at 2 in Figures 2 and 4 of the drawing. Instead of
rollers other suitable apparatus may be employed for drawing or compressing the
armour upon the lining, which may be of any desired construction, such as the
ordinary paper tubes treated with carbonaceous substances.
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 :-
A conduit for electrical conductors made by inserting a tubular lining of soft,
pliable and resilient insulating material within a metallic armour, and then effecting

page_text: close union of the armour and the lining by reducing the diameter of the external
tube.
Dated this 21st don of O
1000
ABEL & IMRAY,
Agents for the Applicant.