Means or Apparatus to be Used in the said Manufacture.
Year: 1887

page_text: Means or Apparatus to be Used in the said Manufacture.
I, HENRY SKERRETT of Great Western Chambers, Livery Street Birmingham in the
County of Warwick, Patent Agent, a communication to him from abroad by John
Henry Dalzell of Pittsburg, Alleghany County, Pennsylvania, United States of
America, 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 :-
This invention relates to an improved type of lead covered electric cable in various
forms, and to the manufacture thereof.
Prior to this invention, lead covered cables containing multiple conductors have
been mostly made according to either of two general methods-One style known as
"anti-induction" cable consists of a number of wires suitably insulated and covered
with lead by the use of a hydraulic press in such manner that the distinctive feature
of anti-induction is imparted, namely that each wire of the finished cable is entirely
enveloped in lead and separated from its companions by the same material. In the
other style of cable known as "bunched cable" the metallic partition between
neighboring wires is omitted and all the wires bunched together separated only by
their insulation. My invention relates to this latter class of cables.
In manufacturing this class of cable, the practice has been to prepare the insulated
wires by laying them up into a bunch or core, then drawing such core into a lead pipe of
somewhat larger internal diameter than that of the core, and finally injecting an insula-
ting compound or substance, liquified, in order to drive out air and fill
up all
spaces. As
this insulation usually solidifies on cooling any flexure of the cable afterwards tends to
make it crack or crumble. This and shrinkage in cooling and uncertainty in the filling

page_text: process, all tend to make open places in the interior, which are objectionable. The
drawing-in process compels the manufacture of short lengths only, owing to the
impracticability of drawing considerable lengths into a pipe of lead.
My invention avoids these objectionable features, and by it I can make the cable in
continuous lengths, the only limit being the ability to handle the product.
In carrying out this part of my invention, I use a preferred form of hydraulic press,
which is shown in vertical section at Fig. 1, while Fig. 2 shows in section the
described forms of bunched cable, the upper being the "drawn-in" type, and the
lower being my improved form.
A is the water cylinder, B the ram, Da stationary head-block held by tie-rods C.
A pillow-block E is bolted on ram B and has an opening a from one side to the top,
where a pipe die b is located. On block E is bolted the lead cylinder F, fitted to
receive the lead-ram G. Cylinder F carries the guide-rods c, which carry the yoked,
to which is attached the hollow core-bar e, which extends down axially through
block D and ram G, and into the lead cylinder to a point just above the die b.
The insulated wires f are passed down from the reels g, through core-bar e and
die b, cylinder F filled with lead, the ram B caused to rise and the lead is forced into
motion downwardly through the die. The wires are bunched together into a
uniform and compact core by the pressure, and the hot and non-elastic lead is packed
closely around this core and into its external cavities or grooves. At the same time
the bunch is covered with a seamless envelope of lead and is drawn into and through
the press. The product is a solid compact cable which cannot have any internal spaces
or like flaws, and obviously can be made in great lengths.
It is important to adjust the core-bar to the proper position for requisite compression
and feeding movement; this will vary according to circumstances.
Sometimes to render the insulation heavier and the strength greater, 1 overlay the
'bunch of insulated wires with a braiding or wrapping of fibrous material, saturate
this in turn with a suitable liquid insulation and then pass the core so prepared down
through the lead-press as before. Such a cable is shown in Fig. 3, where ff are the
insulated wires, h the fibrous covering the final insulation, and k the lead covering
which is compressed thereon and into the external cavities of the core.
The next part of my invention relates to a special form of lead covered cable,
which is especially designed for telephone service, where a large number of wires
start out together, from a central station and are taken off as branches at many
intermediate points, the cable diminishing in proportion as the number of wires
decreases.
Fig. 4 illustrates this feature of my invention.
The starting end in this case contains 13 wires. At m six of these stop and
their ends may be brought out as shown for convenient connection to the branch lines.
The other seven wires continue on as at n the lead envelope k being reduced in
diameter to correspond, and further on any further reduction may be made.
Such a cable can be readily made by slightly modifying the form of press herein-
before described. I illustrate such modification by the elevation Fig. 5, the enlarged
view partly sectional, at Fig. 6 of the upper end of the press, the details of the die at
Fig. 7, and the core-bar and removable lining at Fig. 8. Fig. 9 shows three sections,
illustrating the progressive reduction of wires.
The press itself is as before, consisting of the water cylinder A, ram B, pillow-
block E, tie-rods C, lead cylinder F, head-block D, lead ram G, guide-rods c, yoke d
and core-bar e. I form at the top of pillow-block E a wide groove p deep enough to
receive the die and having converging sides to form a wedge-like recess. The dies
are all alike in external dimensions, differing only in aperture, and are made in two
similar halves 9. A stop r on block E serves as guide for correct position of dies,
and two wedges s are driven alongside the dies to prevent any spreading of the latter.
In operation, when wedges 8 are removed, room is left for the easy removal of the
dies and their substitution by others of different aperture. I proceed as follows:
I insert a die first which corresponds with the smallest section of the cable to be
made, and then start the press in operation, thus forming my already described

page_text: lead covered cable till the proper length is about obtained for that particular section.
At this juncture the desired additional wires are passed down into the core-bar and
the press again started till the added wires have arrived at a point just above the
die 99. The press is then stopped wedges s forced out, dies qq removed and a pair
substituted having the aperture slightly larger so as to take in the additional wires and
allow for the covering k. Wedges s are replaced and the press started and operated
till it is about time for more wires to be added; when the dies are removed as before
and larger apertured dies put in.
The shoulders m left on the external covering k indicate where to cut the latter for
access to the curtailed wires for branching.
The core-bar may if desired, be fitted as shown at Fig. 8 with a split and removable
lining several being in readiness having bores corresponding with the size of bunch
to pass through.
In this manner a cable of any number of wires and length of intermediate sections
can be very readily produced.
What I claim as my invention is as follows:-
1. The improved electric cable comprising a central bunch of wires, individually
insulated and compressed together so as to have no interstitial space, and a lead
envelope for the whole, substantially as described.
2. The improved electric cable comprising a central bunch wires individually
insulated and compressed together so as to have no interstitial spaces, and a lead
envelope compressed around said bunch and into its external grooves, substantially as
described.
3. The process of manufacturing bunched elastic cables consisting in forming a
number of insulated wires into a straight or spirally arranged core or bunch, and then
by hydraulic pressure, compressing upon the same and into the external cavities
thereof a continuous seamless envelope or covering of metallic lead, substantially as
described.
4. The process of manufacturing bunched electric cables, consisting in forming
a number of insulated wires into a straight or spirally arranged core, then compressing
the same and finally compressing thereon and into the external cavities thereof a
seamless envelope or covering of metallic lead, substantially as described.
5. The improved electric cable composed of a number of insulated wires bunched
together and overlaid with a braiding of fibrous material, the whole saturated with a
liquifiable insulating substance or compound, and a continuous lead envelope
compressed around the same and into its external cavities, substantially as described.
6. The herein described process of manufacturing bunched electric cables,
consisting in bunching together a number of insulated wires, overlaying the whole
with a fibrous covering, saturating with a suitable liquid insulating material and
finally compressing upon the same and into the external cavities thereof a continuous
seamless covering of metallic lead, substantially as described.
7. An electric cable composed of a number of insulated wires of different lengths
arranged in concentric groups, the shortest group being on the outside and the longest
at the center, substantially as described.
8. An electric cable composed of a number of insulated wires of different lengths
enclosed in a continuous lead envelope surrounding the same and compressed thereon,
substantially as described.
9. An electric cable composed of a number of insulated wires diminishing in length
and number between one end and the other, and a lead casing or sheath surrounding
the same and correspondingly diminishing in diameter, substantially as described.
10. In the manufacture of lead covered cables by the use of a lead press the method
of varying the diameter or cross section of the cable at intermediate points by altering
the aperture of the forming die while the cable is still unfinished, substantially as
described.
11. In the manufacture of lead covered cables having a variable number of wires at
different points in its length, the method of forming the same, by passing the insulated

page_text: wires through a lead press adapted to cover the bunch with lead, beginning at the
smallest section of the cable, and at the required intervals adding more wires and
changing the die or aperture of the lead press, substantially as described.
12. In a hydraulic lead press for covering electric cables, the combination therewith
of a removable two part die and removable means for holding the same in position,
substantially as described, whereby during the process of covering a cable, the die
may be removed and substituted.
bar
13. In a hydraulic lead cable press the combination of the cylinder F, ram G, core-
and divisible interchangeable dies q, having apertures of different diameters,
with suitable means of holding said dies in position, substantially as described.
e,
14. The combination of the cylinder F, ram G, pillow-block E having groove p,
dies
and wedges, substantially as described.