IMPROVEMENT IN LEAD ARMORED ELECTRIC CABLES AND IN MANDRELS FOR MANUFACTURING THE SAME
Year: 1884

page_text: I RICHARD SOLOMON WARING of Pittsburg County of Allegheny State of
Pennsylvania United States of America Electrical Engineer do hereby declare the
nature of my Invention for "IMPROVEMENT IN LEAD ARMORED ELECTRIC CABLES
AND IN MANDRELS FOR MANUFACTURING THE SAME' and in what manner the
same is to be performed to be particularly described and ascertained in and by
the following statement:—
"
The first part of my Invention relates to lead armored electric cables and is
illustrated in Sheet 1 of the accompanying Drawings in which:
Figure 1 is a perspective view of my improved compound cable.
Figure 2 is a transverse sectional view of the same.
Figures 3 and 4 are views similar to Figures 1 and 2 showing substantially the
same features of invention in grouping the wires, but with a smooth round exterior
instead of a lobed form of exterior covering of the cable.
My Invention relates to certain improvements in compound electric cables, and;
in general terms consists of a body of lead or other equivalent soft, ductile metal or
alloy, such body having passages therethrough enclosing insulated conducting wires,
the wires being arranged in a series of groups in circular order around a central
group, as hereinafter more fully described and claimed:
In the Drawing A represents the body portion of my improved cable, formed, by
preference, of lead, though other soft, ductile metal or equivalent alloy may be
employed adapted to be worked as lead is worked in a press. This body of metal
encloses insulated conducting wires a, each in its appropriate passage, such wires
being enclosed by flow of lead around the same at the point of the mandrel of an
ordinary cable-press, the lead being formed into adhesive union between and
around the wires, by the pressure to which the lead is subjected in the press..
A special feature of my improvement in this cable is the arrangement of wires
embodied therein whereby provision is made for including a comparatively large
number of wires in a cable of small sectional area and light weight, and also
continuous, unbroken walls of lead covering are secured between and around each
and all the wires, not only in the outer parts, but also in the inner or central parts,
of the cable.
e
This feature of improvement may, in general terms, be described as an arrange-
ment in groups, one group of wires occupying the central core or axial part of the
cable, and other groups being arranged at equal intervals around such centre, with
open spaces between the groups of the outer circle, through which lead may flow;
both to the spaces between wires in the central group, and also along the sides of
the outer groups to the spaces between their several wires.
The central group, as shown in the Drawings, consists of a circular arrangement
of wires around a common centre. Surrounding this central group is a series of

page_text: •
groups composed of three wires each, such groups occurring at equal intervals around
the centre.
These outer groups are separated from each other a greater distance than the
individual wires of each group, and they are also placed by preference in the radial
lines of the wires composing the circle of the central group.
This provision is made with reference to passing lead between the outer groups
into the spaces between wires of the central group, and also with reference to
applying lead to each of the outer groups both upon their outer and their adjacent
sides. The lead thus supplied is afforded comparatively wide passages between
groups so that an adequate amount can be introduced to the inner parts of the
cable, without obstruction to flow, and without danger of displacing wires by
pressure of lead thereon.
Also the three-wires composing an outer group occupy relative positions
corresponding to the angles of a triangle. By this provision the greater part of the
surface of each wire is exposed directly to the channels for lead supply, consequently
the wires in such a group can be brought close together and still sufficient lead be
passed into the inner space, between wires, to fill the same. This is the more
readily accomplished because, properly, speaking, lead simply passes into these
narrow spaces from different sides to fill the same, and does not flow through them
to fill some space beyond. For these reasons I prefer to form each outer group of
three wires, occupying relative positions, as shown, but I do not wish to limit my
Invention to this specific number and arrangement, because the groups of the outer
circle may have more or less than three wires and still secure substantially the
same open or free channels for flow of lead between groups both to the centre of
the cable and also to the spaces of the outer groups from their adjacent or inner
sides.
If desired, the exterior of the cable may be given a round form as illustrated in
Figures 3 and 4; I prefer, however, to give the exterior a lobed form, as in
Figures 1 and 2. This is done by means of grooves a¹, formed longitudinally in
the body A, between the outer groups of wires. Not only is greater economy
secured in the use of lead by. this feature of construction, but also greater flexibility
of the cable, because the several ribs which enclose the outer groups of wires can
move toward or from each other somewhat and thereby facilitate bending the cable
without danger of unduly compressing the enclosed wires.
By the features of arrangement herein described, I am enabled to multiply
greatly the number of wires without enlarging materially either the sectional area
or the weight of the cable. This is in practice a very important feature, looking to
economy in manufacture and commercial success in use.
The second part of my Invention relates to mandrels for manufacturing lead
armored electric cables and is illustrated on Sheet 2 of the Drawings, in which :
Figure 1 is an end view of my improved mandrel looking upon the point.
Figure 2 is a transverse sectional view taken in the plane of the line X X
Figure 3, and looking towards the point of the mandrel.
.
Figure 3 is a longitudinal sectional view, the plane of section being indicated by
the line X', X, Figure 1.
Figure 4 is a transverse sectional view taken on the plane of the line X"X"
Figure 3, looking towards the point.
This part of my Invention relates to mandrels for cable presses designed for
making cables having a circular arrangement of wires, and in general terms it
consists of a tapering body of metal having wire-passages therethrough, such
passages being arranged in groups, in circular order around a central group, with
grooves extending longitudinally on the tapered surface between groups of wire-
passages, terminating at the point of the mandrel in nipples or tubes, as bereinafter
more fully described and claimed.
In the Drawing; A represents. a tapering body of iron, steel, or other. suitable
metal, having at its larger end or base a threaded socket a for making attachment
to the threaded end of the core-bar B of the press, the tubular passage of which

page_text: registers with the socket chamber A' in the mandrel body. Extending from
chamber A, to the point or smaller end of the mandrel body, are made a series of
passages a', which are arranged in different groups, one such group occupying the
central or axial part of the mandrel, and others composed of three passages which
occur at intervals in circular order around the central group.
2
On the exterior tapered surface of the mandrel body, in lines between the
groups of passages forming the outer circle, are made grooves c. These grooves
increase in depth toward the point, where they emerge partially' within the circle
of the central group of passages. Their purpose is to provide passages for flow of
lead past the outer groups of passages to the inner parts of the mandrel-passages,
or to the cable made thereby.
The mandrel, at and near the point, is given a lobed form by these grooves,
see Figure 4, Sheet 2, each such lobe including or carrying one of the three passage
groups which together form the outer or surrounding circle. At the point of the
mandrel the several wire-passages a¹, terminate in nipples or tubular extensions e,
which are formed by cutting grooves c', in the metal between the separate passages
of each group and also cutting channels or narrow passages c², across the end
connecting the grooves c¹, between the openings to the separate passages. The
enclosing-walls of the wire passages are thus reduced to comparatively thin and
light body, and to secure adequate strength to withstand the pressure required in
work, the channels c are made shallow or of less depth, say about one-half the
depth of the grooves c¹. Greatest working pressure of lead upon the nipple
surfaces is toward the centre of each group, and by making the end channels c
shallow a web or body of metal is secured in the centre of each group between its
passages, which assists materially in sustaining the pressure of lead. Lead flowing
along the grooves c', under pressure thereon within the cylinder of the press, is
applied directly to the outer surfaces of all the wires contained in the outer circle
of groups, and is also delivered or directed into the grooves c', and channels c²
between all the nipples or passages, both in the inner and outer groups.
Provision is thus made for securing an adequate supply of lead between all the
nipples, which, uniting around the nipples under pressure, passes off from each,
forming continuous, unbroken walls of covering for each and all the wires of the
cable.
So far as I am aware it is new with me to provide for grouping wires in circular
order in this class of cables. By means of this provision I am enabled to bring
the wires into close proximity in the cable, and secure the continuous unbroken
body or walls of covering requisite to successful use for electrical purposes.
These features of construction and advantage are very useful in practice,
because it enables me to cover a large number of wires with a comparatively small
amount of lead, and also to combine the same into a single compound cable of
comparatively light weight and small sectional area.
It will be observed that the passages composing the circle of the central groups,
correspond in number to the groups forming the outer or surrounding circle, and
that they are in the same radial lines as the outer groups.
This feature of arrangement is designed with reference to carrying the exterior
grooves c well into the inner circle of passages, and thereby conduct lead supply
into the central group of passages. The cable may. be given any desired form of
exterior, such form being imparted to it, as heretofore practiced in the art, by the
shape of the die-opening employed. I prefer a form in cross-section substantially
similar to the section of mandrel shown in Figure 4 Sheet 2.
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:
First. An electric cable having a body of soft ductile metal or equivalent alloy,
enclosing insulated conducting wires, each in its appropriate passage through the
body, such wires being arranged in distinct groups at intervals around a central
group, the distance between adjacent wires of a group being less than the

page_text: distance between the successive groups composing such outer circle, substantially
as set forth.
f
1
Second. An electric cable having a body of soft ductile metal or equivalent alloy,
enclosing insulated conducting wires each in its appropriate passage through the
body, such wires being arranged in distinct groups, in circular order around a
central group, the central group being composed of wires arranged in circular order
around a common centre, the wires of such circle occurring in the radial lines of
the surrounding groups substantially as set forth.
Third. An electric cable having a. body of soft ductile metal or alloy, enclosing
insulated conducting wires in separate passages therethrough, such wires being
arranged in distinct groups around a central group, the outer groups being composed
of three wires each, the distance between such wires being less than the distance
between successive groups, substantially as set forth.
t
Fourth. An electric cable having a body of soft ductile metal or alloy, enclosing
insulated conducting wires in separate passages therethrough, such wires being
arranged in distinct groups arranged in circular order around a central group, with
grooves made longitudinally in the exterior surface of the body between the groups
composing the outer circle substantially as set forth.
Fifth. A mandrel A for a cable-press, having groups of tubular nipples thereon,
such groups being arranged in circular order around a central group, and having
grooves c in its side. Such grooves extending longitudinally between successive
groups of nipples, substantially as set forth.
Sixth. A mandrel A, for a cable-press, having wire passages therethrough
terminating at the point in separate groups of nipples, such groups being arranged
in circular order around a central group, the outer circle of groups being divided
one from another by grooves cut radially between them, such groove being extended
in depth, at the point of the mandrel to or within its central group of nipples
substantially as set forth.
Seventh. A mandrel 'A, having wire-passages therethrough, such passages
terminating at the point in separate groups arranged in circular order around
some central group, with grooves c separating the groups of the outer circle,
smaller grooves c' between the individual passages of each group, and channels c³
connecting the grooves c¹ across the ends between passages, substantially as
set forth.
Eighth. A mandrel for cable press, having passages therethrough terminating at
the point in separate tubular nipples, such nipples being arranged in groups of
three around some central group, with surface grooves on the mandrel extending
to its point. between the outer groups of nipples, substantially as set forth.
Ninth. A mandrel for a cable press, having wire-passages therethrough termi-
nating at the point in separate groups of nipples, such groups being arranged in
circular order around and in the radial lines of the nipples of a central group,
with surface grooves on the mandrel, dividing the several outer groups one from
another and extending in depth within the circle of nipples of the inner group,
substantially as set forth.
D414th 1.
7001