An Improved Method of and Apparatus for Covering Electric Wires.
Year: 1891

page_text: Date of Application, 21st Apr., 1891-Accepted, 23rd May, 1891
COMPLETE SPECIFICATION.
An Improved Method of and Apparatus for Covering Electric Wires.
I, JABEZ ELLIS WALCOTT, of corner of Washington and Division Streets,
North Attleborough, County of Bristol, State of Massachusetts, United States of
America, Tool Maker, do hereby declare the nature of my invention for "AN
IMPROVED METHOD OF AND APPARATUS FOR COVERING ELECTRIC WIRES,"
and in what manner the same is to be performed, to be particularly described
and ascertained in and by the following statement, reference being had to the
accompanying drawings forming part of this Specification :—
My invention relates to the protecting covers or sheaths of insulated or non-
insulated electric conductors, and the object of my invention is to produce, by
means of a rapid and continuous method, an improved form of covering or
sheath which shall perfectly encase the wire or wires and which shall be capable
of enduring, without detriment, all of the strains, including handling, coiling and
suspension, to which this class of structures is subjected.
To this purpose my invention consists in the peculiar and novel method of
covering the wire or wires and also in the peculiar and novel apparatus for
carrying said method into effect, as hereinafter described and claimed.
In order that my invention may be fully understood, I will proceed to describe
it with reference to the accompanying drawings, in which,-
Figure 1 is a side elevation of my improved apparatus.
Figure 2 is a front elevation of the forming die-plate used in covering a single
wire.
Figure 2ª is a similar view of the die-plate used in covering three wires.
Figure 3 is a detached view of the rolls for enclosing the wire in the sheath and
for forming the uniting lips.
Figure 4 is a similar view of the finishing-rolls.
Figure 5 is a front elevation of the finishing die-plate used in covering the
wire or wires.
Figure 6 is a detached sectional view of the wire as it emerges from the rolls
shown in Figure 6.
Figure 7 is a similar view of the three wires as they emerge from said rolls.
Before entering into a detailed description of my new method and apparatus for
carrying said method into effect, I would state that my method is based upon a
certain property of lead, or of the composition of lead and tin, or of any other soft
metal which is capable of being laid around one or more wires to form a sheet
armour; my improved sheath or covering being formed of either of such metals or
compositions. The property referred to is that of uniting homogeneously upon
the simple application of heat; such unison being not only homogeneous but strong,
durable, and not readily apparent after the substance has been so treated. Thus
if two continuous surfaces of lead or other soft metal be subjected to the action of
a fusing heat such surfaces will unite so perfectly that the mass will possess a
perfectly homogeneous character, and such united surfaces will not only resist all
wear as a single surface but all traces of their previous divided character will be
completely obliterated. Great difficulty has been experienced in adapting lead or
similar metal to such use.
Heretofore metal has been applied to the wire or wires in the form of a strip or
ribbon the meeting edges of which have been laid either spirally around or parallel
to the axis of the wire and in either case such edges have been united by solder.
Practical observation and experience prove that the sheath thus formed is seriously
deficient both in lasting properties and in resisting the strains incident to handling
and coiling and uncoiling. This serious defect is due to the fact that the

page_text: soldered union of the contiguous edges of the strip destroys the homogeneous
character of the covering, and consequently the sheath is extremely liable to
become ruptured or perforated at the points of such union.
Now my improved method consists essentially in forming this union of the same
substance as that of which the sheath is formed, whereby I secure perfect homoge-
neousness in the sheath. To this purpose I form a raised lip upon each contiguous
margin of the strip and then "burn or fuse these lips together; the result being
that the sheath has apparently and in reality all of the appearances and properties
of an integral envelope. There are certain subordinate steps in perfecting my
method, to wit; a preliminary bending and rolling of the strip, the use of tallow
previous to the "burning" or fusion of the joint, and the finishing of the joint.
The result of my improved method is that the sheath is as finished in appearance
and as capable of resisting rupture or perforation and strain as a solid cylindrical
mass or bar.
I will now proceed to describe the apparatus whereby my improved method is
carried into effect. The operative parts, hereinafter described, are mounted upon
a table or frame A which may be of any suitable or preferred form capable of
properly supporting said parts. Above this table and at one end thereof is placed
a drum or reel B upon which the wire or wires are wound; such wire being
either covered with a suitable non-conducting coating, or naked, as desired. Below
this table, and at the same end upon which the drum B is mounted, is placed the
reel or drum C upon which the strip of lead or other soft metal c is wound. The wire
or wires and the metal strip pass from the drums B, C, to a drum L which
is located at the opposite end of the frame. The covered wire in finished condition
is wound upon the drum L which is revolved by suitable gearing as, for instance,
the beveled-gear mounted on the shaft I, which carries the drum, and the beveled
pinion mounted on the shaft which is driven by a pulley by means of which
motion is imparted to the gearing through a driving-belt from a suitable motor.
The drum L exerts the requisite tension upon the wire and metal strip and feeds
them properly through the machine. As the wire or wires and metal strip pass
through the machine the strip is acted upon successively by the forming die-
plate D, the forming-rolls E, the reservoir F, the blow-pipe G and chamber H, the
covering-rolls I and the finishing die-plate J, after which the covered wire is
guided, by the guiding-pulleys K, to the winding-drum L. I will now particularly
describe each of the devices which are interposed between the drums B, C, and the
drum L; arranging such description in the order in which said devices act.
The wire from the upper drum B passes under the pulley 6' while the
metal strip c from the drum C passes over the pulley c¹ and from thence the wire
and strip pass, the former above the latter, in parallel lines to the forming die-
plate D. The die-plate D is placed upright upon the frame A and containing an
aperture through which the wire and strip pass during which passage the strip is
folded partially around the wire. As shown in Figure 2 this aperture is
U-shaped and a die-plate with this form of aperture is used when the sheath
is applied to a single wire. In this instance the stripe is bent up into U-form so
as to partially enclose the wire b, as is clearly shown in Figure 2. In Figure 24
the die-plate aperture is of a peculiar form by means of which three wires
are partially covered, and it is to be understood that my invention contemplates
the covering of one or any desired number of wires, the form of the apertures
in the die-plate being such, in any given instance, as to properly prepare the
covering for the action of the next successive device.
The wire or wires and the strip pass from the forming die-plate D to the forming-
rolls E, shown in Figures 1 and 3. These rolls are peripherally grooved and are
mounted horizontally upon the frame A in any suitable manner, as, for instance,
upon the axles e, e, as shown in Figure 3. The lower flanges of the rolls E come
into contact while their upper flanges, being of less diameter, are separated
sufficiently to permit the margins of the strip c to pass between them. The thickness
of the rolls E being less than half of the width of the strip c, when bent by the

page_text: die-plate D, produces the upturned, continuous and parallel lips c³, c³, upon the upper
side of the strip, and the grooves of the rolls E serve to bend the strip almost
completely around the wire, there being but a slight degree of separation between
the lips, c, as is shown in Figure 3. It will be readily perceived that a similar
result will be produced by the rolls E when three wires (or more than one wire) are
being operated upon, as is shown in Figure 7.
The wire or wires and the strip now pass, from the rolls E, beneath a reservoir F
which may be provided with a cock or valve to regulate the discharge of the
contents. This reservoir contains tallow which is caused to flow down upon the
two lips c³, c³, as the strip and wire or wires are fed along the machine.
From the reservoir F the wire or wires and strip pass to the blow-pipe G and
burning-chamber H, where the two lips c³, c, are burned or melted down. The
pipe G is shown as a hydrogen blow-pipe and is placed in inverted position above
the chamber H into which the flame from said pipe is blown. The chamber H is
made of fire-brick or any other substance which is adapted to withstand the action
of intense heat. The precise form of this chamber may be of any such character
as will permit of the free passage of the wire or wires and the strip, and concentrate
the heat from the flame within itself and upon the lips of the strip. It is also
important to observe that any suitable device, other than the blow-pipe, may be
used to produce the requisite heat for application to the lips c², c².
After being acted upon by the blow-pipe flame, or other heating agent, the wire
or wires and the strip pass from the chamber H to the covering-rolls I, I, shown in
Figures 1 and 4. These rolls are mounted vertically one above the other upon the
frame and have horizontal axles i, i, through the medium of which said rolls are
driven. The peripheries of these rolls are grooved and the flanges at the margins
of said grooves are maintained always in contact, so that as the wire or wires and
the strip enter between the rolls the lips c², c², which are in a soft condition, are
rolled down flush with the external surface of the strip and the latter is thus
converted from a bent strip to a complete sheath or covering. These rolls not only
roll down the lips c³, c³, but cause said lips to perfectly unite so that almost all
traces of the lips are obliterated and the character of the sheath is as perfectly
homogeneous as though said sheath were an integral tube. The tallow which was
previously applied to the lips serves to insure this perfect union.
After the operation of the rolls I, I, it only remains to finish the sheath. For
this purpose the wire or wires and the sheath pass through the finishing die-plate J
shown in Figures 1 and 5. This die-plate has a circular aperture in passing through
which the outer suface of the sheath is properly finished and all traces of the joint
thereof are perfectly obliterated. Figure 5 shows the die-plate for finishing single-
wire cables and the only difference between this and the plate for finishing double
or treble wire cables is in the increased size of the aperture.
From the plate J the cable passes between the guiding-sheaves K and thence to
the drum L.
I have not shown any devices for driving the rolls E, I, nor for conducting the
fuel to the pipe G, as such devices may be readily arranged by anyone skilled in
such matters.
Thus it will be seen that the method and apparatus are simple and produce,
rapidly and by continuous steps, a sheath or covering which is entirely free from
the serious defects heretofore found in such coverings.
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 ;
Claim 1. An improved method of covering wire with sheet metal, the same con-
sisting in bending the strip around the wire or wires and forming lips or raised
edges upon said strip, and then burning said edges together, substantially as and for
the purposes specified.

page_text: 2. An improved method of forming covers or sheaths for wires, the same con-
sisting in bending a soft metal strip partially around the wire or wires and forming
raised edges or lips thereon, then burning or fusing said lips, and finally rolling
down said fused lips, as set forth.
3. An improved apparatus for forming soft-metal covers or sheaths for wires,
consisting of a forming die-plate for bending the strip partially around the wire or
wires, a pair of rolls for forming raised edges or lips upon said strip, a heater for
burning down said edges, and a pair of rolls for depressing said burned edges, sub-
stantially as described.
4. The combination with a suitable frame carrying the drums B, C, and L, of
the forming die-plate D, the forming rolls E, the reservoir F, the pipe G and
chamber H, the covering-rolls I, the finishing die-plate J, and the guiding-sheaves K,
all constructed and arranged to operate substantially as described.
Dated this 14th day of March A.D. 1891.
JABEZ ELLIS WALCOTT.
In presence of :-
JOSEPH A. MILLER, Jr.
HENRY J. MILLER.
Haseltine, Lake & Co.,
45, Southampton Buildings, London, Agents for the Applicant.