IMPROVEMENTS ON PROCESSES AND APPARATUS
Year: 1882

page_text: LETTERS PATENT to John Joseph Charles Smith of The town of College Point
in the County of Queens in the State of New York one of the United States
of America for an Invention of IMPROVEMENTS ON PROCESSES AND APPARATUS
PROVISIONAL SPECIFICATION left by the said John Joseph Charles Smith
at the Office of the Commissioners of Patents on the 7th October 1882.
JOHN JOSEPH CHARLES SMITH of the Town of College Point in the County of
Queens in the State of New York, one of the United States of America, "IMPROVE-
MENTS ON PROCESSES AND APPARATUS FOR COVERING WIRE FOR ELECTRICAL
PURPOSES "
Various modes have been devised and adopted for covering wire with insulating
material in some of which strips of rubber have been wrapped either longitudinally
or spirally on the wire. In wrapping the material spirally on the wire it is
difficult or impossible to tightly close the joints unless several layers are applied
causing a waste of material.
It is likewise difficult or impracticable to form a perfect joint or exclude all air
between the covering and the wire by bringing the material together edge to edge
when the covering is applied longitudinally as in some methods, owing to the lack
of surface to which sufficient pressure may be applied or the manner in which it
is done.
It is very important and essential that the material shall be drawn so tightly
around the wire as to expel and exclude air between the wire and the covering.
A further difficulty occurs in the modes heretofore employed from the necessity
of using a considerable thickness of the insulating material, thus involving greater
expense and producing a body which if the compound is to be hard or even semi-
hard vulcanized rubber will become too rigid so that the covered wire will not
possess the necessary flexibility.
In order to overcome these and other difficulties in the covering of wire with
insulating material for electrical purposes the present process has been devised,

page_text: which consists essentially in taking rubber composition or other vulcanizable
compound or any other suitablo waterproof insulating compound in its plastic
state, laying it in a thin film or sheet on a woven or other sufficiently strong fabric,
pressing them together by calendering or otherwise, so as to incorporate the rubber
with the cloth, then cutting tho so-prepared sheet in a long strip of sufficient width
to reach around the wire longitudinally, leaving a surplus for a joining flange
drawing this tightly around the wire and bringing the faces of the compound together
with pressure so that tho rubber is inseparably united around the wire. The
projecting flange or edge of rubber and fibrous material thus produced, is then cut
off so as to leave the wire covered with a thin jointless film or covering of rubber
composition surrounded by a fibrous envelope after which the covering is vulcanized
on the wire by the requisite degree of heat applied in any usual or suitable
manner, but preferably through the medium of a water bath and under heavy
pressure, or packing in powdered soap stove.
The covering strip is conveniently produced by laying the combined sheet of
woven fabric and rubber composition around a large metal drum equal in length to
the width of the sheet, joining together the meeting ends of the plastic rubber
composition and woven fabric so as to form a connected and jointless cylinder of
rubber with its fibrous backing and cutting this cylinder by means of a revolving
circular cutter spirally around the drum so as to produce a continuous strip of the
required width and of great length.
The invention further relates to machinery or apparatus for carrying the process
into effect.
The machine is constructed with a guide for the covering strip formed with a
longitudinal groove, a guide through which the wire is introduced longitudinally
above the strip, a grooved pressure wheel over the central longitudinal groovo in
the strip-guide beneath which whoel the wire is passed so as to be pressed and
embedded into the covering material, and is with the latter depressed into the
longitudinal groove, deflecting studs or guides serving to turn the edges of the
covering strip into vertical position on each side of the enibedded wire, a pair of
horizontal compression rolls or wheels formed in the lower corners of their
peripheries with quarter circular grooves which in conjunction with the longi-
tudinal groove beneath form a circular opening to pass the covered wire, the said
compression rolls receiving between their meeting faces the upturned sides of the
covering strip drawing the said strip tightly around the wire and pressing the sides
together faco to face so as to unite the plastic material over the wire effectually
forcing out and excluding air from within the envelope and leaving a projecting
flange which is removed by a pair of rotary cutters.
The machine is further provided with a pair of grooved traction rolls acting on
the covered wire and serving to draw it through the machine.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Joseph Charles Smith in the Great Seal Patent Office on
the 6th April 1883.
JOHN JOSEPH CHARLES SMITH of the Town of College Point in the County
of Queens in the State of New York one of the United States of America
"IMPROVEMENTS ON PROCESSES AND APPARATUS FOR COVERING WIRE FOR
ELECTRICAL PURPOSES"
Various modes have been devised and adopted for covering wire with insulating
material in some of which strips of rubber have been wrappe either longitudinally
or spirally on the wire. In wrapping the material spirally on the wire, it is
difficult or impossible to tightly close the joints unless several layers are applied,
causing a waste of material.
It is likewise difficult or impracticable to form a perfect joint or exclude all air
between the covering and the wire by bringing the material together edge to edge
when the covering is applied longitudinally as in some methods owing to the lack
of surface to which sufficient pressure may be applied or the manner in which it
is done.
It is very important and essential that the material shall be drawn so tightly
around the wire as to expel and exclude air between the wire and the covering.
A further difficulty occurs in the modes lieretofore employed from the necessity
of using a considerable thickness of the insulating material, thus involving greater
expense and producing a body which if the compound is to be hard or even semi-
hard vulcanized rubber will become too rigid so that the covered wire will not
possess the necessary flexibility.
In order to overcome these and other difficulties in the covering of wire with
insulating material for electrical purposes the present process has been devised
which consists essentially in taking rubber composition or other vulcanizable
compound or any other suitable waterproof insulating compound in its plastic state,
laying. it in a thin film or sheet on a woven or other sufficiently strong fabric,
pressing them together by calendering or otherwise so as to incorporate the rubber
with the cloth, then cutting the so-prepared sheet in a long strip of sufficient
width to reach around the wire longitudinally, leaving a surplus for a joining flange
drawing this tightly around the wire and bringing the faces of the compound
together with pressure so that the rubber is inseparably united around the wire.
The projecting flange or edge of rubber and fibrous material thus produced is then
cut off so as to leave the wire covered with a thin jointless film or covering of rubber
composition surrounded by a fibrous envelope after which the covering is vulcanized
on the wire by the requisite degree of heat applied in any usual or suitable manner,
but preferably through the medium of a water bath and under heavy pressure or
packing in powdered soapstone.
The covering strip is conveniently produced by laying the combined sheet of
woven fabric and rubber composition around a large metal drum equal in length to
the width of the sheet, joining together the meeting ends of the plastic rubber
composition and woven fabric so as to form a connected and jointless cylinder of
rubber with the fibrous backing and cutting this cylinder by means of a revolving
circular cutter spirally around the drum so as to produce a continuous strip of the
required width and of great length.
The Invention further relates to machinery or apparatus for carrying the process
into effect.
The machine is constructed with a guide for the- covering strip formed with a

page_text: longitudinal groove, a guide through which the wire is introduced longitudinally
above the strip, a grooved pressure wheel, over the central longitudinal groove in
the strip-guide beneath which wheel the wire is passed so as to be pressed and
embedded into the covering material and is with the latter depressed into tho
longitudinal groove, deflecting studs or guides serving to turn the edges of the
covering strip into vertical position on each side of the embedded wire, a pair of
horizontal compression rolls or wheels formed in the lower corners of their
peripheries with quarter circular grooves which in conjunction with the
longitudinal groove beneath form a circular opening to pass the covered wire, the
said compression rolls receiving between their meeting faces the upturnued sides of
the covering strip drawing the said strip tightly around the wire and pressing
the sides together face to face so as to unite the plastic material over the wire
effectually forcing out and excluding air from within the envelope and leaving a
projecting flange which is removed by a pair of rotary cutters.
The machine is further provided with a pair of grooved traction rolls acting on
the covered wire and serving to draw it through the machine.
In order that the invention may be fully understood the process and apparatus
will now be described with reference to the accompanying Drawings in which,
Figure 1 is a plan view of the apparatus.
Figuro 2 is a side elevation thereof.
Figure 3 is a vertical longitudinal section of the same on the line 3. 3 Figure 1.
Figure 4 is a transverse section thereof on the line 4. 4 Figures 1 and 2.
Figure 5 is a perspective view illustrating the mode of applying the covering
material and showing some details of the apparatus.
Figure 6 is a sectional elevation also showing the progress of the wiro and
covering material through the machine.
Figure 7 is a perspective view illustrating the mode of cutting a long continuous:
strip from a sheet of covering material placed on a drum.
A suitable frame. work supports a bed or table 2 in the centre of which is a
horizontal guide bar 3 formed with a semi-circular groove 1.
This guide bar forms the bottom of a longitudinal depression in the bed or table
of sufficient width and depth to receive and guide the covering strip which is
formed of plastic rubber composition or other suitable vulcanizable material laid on
a backing of woven fabric with pressure which may be applied by means of calendar
rolls so that the backing becomes embedded in and incorporated with the plastic
composition.
Across the guide bar 3, is a wire guide 4 with a suitable opening to feed the wire
centrally to the covering strip as they are together passed through the machine
and in advance of this is a grooved wheel 5 set directly over the semi-circular
groove in the guide bar 3 and mounted on a shaft 6 which turns on pivots 7
mounted in boxes 7 held down by springs 8, so that the grooved wheel bears on
tho wire with a yielding pressure..
In advance of the vertical wheel 5 are a pair of horizontal narrow rollers or
wheels mounted on vertical shafts 10 and pressed together by strong springs 11
which are adapted to yield in the event of any foreign matter or undue thickness
of material entering between the rollers but in the ordinary operation of the
machine will draw the envelope tightly around the wire and compress the projecting
edges of the covering material together; face to face with considerable force as
hereinafter described.
The lower faces or corners of the horizontal rolls or wheels 9 are provided with
quarter circular grooves forming together a semi circle and form with the semi-
circular groove in the guide bar 3 a circular opening corresponding in size with the
thickness of the wire including the covering, so as to fit tightly over the upper
half of the wire and covering and draw and press the covering firmly around the
wire. In advance of the horizontal pressing or closing rolls 9, is a guide 12 slotted
to permit the passage of the projecting edge or flange of the wire covering and in
advance of this are a pair of rotary horizontal cutters 13 by which the said
J

page_text: projecting edge is removed so as to leave a smooth and even surface. The covered
wire passes between a pair of rubber rolls 14 which serve to draw it through the
machine and assist the feed.
Between the wire guide 4 and the grooved pressure wheel 5 are a pair of studs 15
serving to turn up the edges of the covering strip so that they are readily brought
into vertical position by a second pair of guides 16 between the vertical pressure
wheel 5 and horizontal pressure rolls 9.
The operation of the apparatus is illustrated in Figure 5.
The copper wire to be covered is fire-tinned or drawn through a suitable bath of
soft solder which may be made of one part of lead and one part of tin. This
tinning of the wire is for the purpose of preventing the sulphur-in the rubber
compound from acting on the copper.
A suitable strip C of covering material prepared as herein before described is
applied over the grooved guide bar 3 passed under the wire guide 4 and beneath
the grooved pressure wheel 5, the edges of the strip being turned upward by the
studs or guides 15. 16 around the wire W which is introduced through the opening
in the wire guide 4 and passed beneath the grooved wheel 5. The latter applies
sufficient pressure to the wire to embed it in the rubber composition or other
plastic material, which bends and yields to the shape of the semi-circular groove in
the guide bar 3 underneath thereby partly turning up the edges of the strip.
The sides of the covering strip turned up as described pass in vertical position
between the borizontal pressure rolls or wheels 9, the quarter circular grooves in
the lower corners of which adapt them to tightly embrace the covered wire
drawing the covering material tightly around the wire completely pressing out all
air and by their vertical faces pressing between them the projecting edges of the
covering strip face to face effectually incorporate the meeting surfaces of the plastic
composition, so as to form a jointless envelope of rubber or other plastic material
around the wire from which air is completely expelled.
It is preferred to adapt the horizontal rolls 9 to act with sufficient pressure to
partially or completely force out the plastic composition from between the surfaces
of the cloth at the point where this pressure is exerted bringing the cloth itself
into close contact so that when the projecting flange formed by the united edges of
the covering strip is removed by the rotary cutters 13 the wire will be left with a
jointless covering of the rubber or other plastic material and an external envelope
of fibrous material firmly incorporated therewith and having a smooth and uniform
exterior surface.
This fibrous envelope adapts the wire to be handled in any manner directly it
leaves the machine and it may without detriment be coiled up for placing in the
vulcanizer.
The cloth backing possesses the necessary tenacity and strength to give a firm
hold to the pressure rolls 9 in drawing the covering tightly around the wire and
to both these and the traction rolls 14 in drawing the wire through the machine.
Should a wire be desired which shall have an additional metal covering over
the gum and fibrous covering this machine is very well adapted to lay such a metal
covering on the insulated wire. When the rubber covered wire is vulcanized it is
passed again through the machine but instead of a strip of cloth combined with
plastic material a strip of lead or tin is used of such a thickness as is desired for
the metal covering and of such width as to envelope the insulated wire leaving a
surplus to form a flange for the closing or pressure rolls 9 to act on as in the
application of the strip of insulating and fibrous covering strip already described.
If the pressure rolls 9 are set to press the metal covering very tightly the edges of
the metal will unite by the pressure the projecting flange being severed and
trimmed off by the rotary cutters, thus laying a thin but firm and smooth metal
covering on the wire. If the machine shall be used for applying such an additional
covering the grooves in the guide-bar 3 guide-wheel 5. and pressure rolls or wheels 9,
must of course be made larger and the rotary cutters must be correspondingly
elevated to allow for the increased size of the covered wire.
.

page_text: Combining the plastic composition with a backing of fibrous material by
pressure or calendering so that it becomes incorporated therewith before its
application to the wire, obviates much of the difficulty experienced in handling the
plastic rubber composition and produces a combined fabric to which the necessary
force may be applied without injury in stretching the insulating covor tightly
around the wire with pressure so as to exclude air and form a jointless envelope.
It also enables the use of other water-proof insulating materials which it would
be difficult or impossible to apply uniformly to the wire without such backing.
By the use of a backing of woven material and a vulcanizable composition.
sprend thereon cut into a narrow strip in the manner described laying this strip
around the wire longitudinally and joining it on-one sido by means of pressure on
the surface of the covering strip which forms a flange when brought together
round the wire, the covering is drawn very tightly over the wire, effectually
excluding air insuring a uniform covering without fault with a very thin but solid
and substantial film of insulating material.
By using a very thin but uniformly applied layer of rubber a rubber compound
may be employed which can be vulcanized whint may be termed three quarter
hard but possessing all the good resisting qualities of hard rubber against the bad
influences of lient, atmosphere, gases oil, fungus growths, or attacks of insects,
without rendering the covering liable to fracture when the wire is bent or
twisted.
It is a well known fact that hard rubber or a rubber compound which is nearly
hard vulcanized is very pliable when very thin, somewhat like a sheet of paper,
especially so when in firm combination with woven fabric therefore a thin layer of
such compound on the wire will have the necessary pliability.
It is also an established fact that a hard or nearly hard vulcanized rubber sheet
will have the greatest resistance of any gummy or waterproof composition known
against the bad influences of water, danip in unventilated places, foul atmosphere,
fungus growth, acids, oil or greasy mintters and the attack.of.insects.
It is also well known that hard vulcanized rubber compounds have been used
for covering wire, but on account of improper methods and machinery the covering
had to be laid on so thick as to deprive the wire of its required state of flexibility
for practical use. Henco the softer compositions are usually employed and
resorted to.
In the improved process the rubber is brought in close contact with the wire
without the use of cement. Cement is detrimental in various ways. It is liable
to become porous in vulcanization and to disintegrate in use, thus impairing the
tight covering of the wire.
Another very important advantage in the process consists in the uniformity with
which the insulating covering is laid around the wire, thus permitting the use of
a very thin film without endangering perfect insulation or dislocating the wire
from its central position whereas with processes and machines which require the
use of plastic coverings of greater thickness waste of material and imperfection in.
the work frequently result from the lack of uniformity in the thickness of the
covering material, which is very often thin on one side of the wire so much so
that by the least handling the wire is exposed..
Another advantage of the process is; That by the firm combination of a thin
sheet of rubber with the cloth the fibrous covering and the gum insulation are
applied at one operation and such fibrous covering is in perfect combination with
thie gum.
It is of great advantage to firmly combine the plastic compound (be it rubber
or any other flexible or plastic composition) with a suitable sheet of fibrous or
pliable material and then to cut it in strips or ribbons for laying it around the
wire, because hy so doing the plastic compound forms by such combination a strip
or ribbon of great strength, which may be subjected to a greater strain, without
tearing asunder or strotching to an undesirable degree. The strips are readily
reeled up for use on the covering machine, furthermore the firm combination of the
->

page_text: fibrous strip with the plastic material forms an inseparable fibrous protecting
envelope over the thin covering of gum insulation and gives valuable advantage to
readily handle the wire during the process of covering and vulcanization and
avoids also the extra labor to apply a fibrous covering over the rubber after
coating the wire with plastic material as it is usually done.
It is also well known that in other methods of covering wire, sheets, strips or
ribbons of fibrous material have been interposed between the strips or sheets of
gum to prevent the adhesion of the plastic strips between each other when reeled
up or to permit the plastic strip to be more readily carried by the covering machine
and in others fibrous strips or sheets have been painted over with some solutions
of gums, waxy or oily substances and wrapped on the wire spirally as a protection
of some easily injured coatings. These modes differ essentially from that above
described in which the fibrous or pliable sheet or strip and the gum are inseparably
united and then applied longitudinally to the wire drawn tightly around it and
united face to face.
The application of solutions of rubber, gutta percha and other vulcanizable gum,
to wire in one or more layers, involves not only great expense in labor and
material, but such coatings are unfit to undergo the process of vulcanization,
because no matter how dry the coating may be, the vulcanization invariably
renders it porous on account of the volatile nature of such solvents, as a great
portion of the solvent necessarily remains with the gum and is driven off only by
the heat of vulcanization, thereby producing blisters and pores.
A sheet of solid rubber composition or other vulcanizable gum however thin
applied to the fibrous covering and reduced to the desired thinness by calendering
or pressure, may be relied on to produce a solid and perfect sheet, free from pores
or blisters if the vulcanization be properly performed.
The following is claimed as new in the above described Invention:-
First. The process of covering wire for electrical purposes, by preparing sheets of
plastic insulating material combined. by pressure or calendering so as to incorporate
the plastic composition with the flexible backing, cutting in a long strip of requisite
width, drawing this longitudinally tightly around the wire, pressing the meeting
faces of the composition together on one side of the wire, thus producing a
jointless insulating envelope and cutting off the projecting edge or flange.
Second. The grooved guide-bar substantially as and for the purposes set forth.
Third. The combination of the wire-guide 4, and the bar 3 beneath the same in
a recess for guiding the strip substantially as described.
Fourth. The grooved guide wheel 5 formed and applied substantially as and for
the purposes set forth.
Fifth. The combination of the grooved guide-bar 3, and the grooved wheel 5, for
pressing the wire into the covering material within the groove of guide-bar 3,
substantially as described.
Sixth. The pair of closing pressure-rolls 9, 9 formed with quarter circular grooves
or depressions in the lower parts of their peripheries substantially as and for. the
purposes set forth:
Seventh. The combination of the grooved wheel 5. and the pressure or closing
rolls 9 substantially as and for the purposes set forth.
Eighth. The combination with the guide bar 3, and grooved wheel 5, of the
pair of closing pressure rolls 9, grooved on the lower parts of their peripheries
to adapt them to draw and compress the covering tightly round the wire as
explained.
Ninth. The combination of the slotted guide 12, and rotary cutters 13,
substantially as and for the purposes set forth.
Tenth. The combination with the grooved wheel 5, and guide bar 3, of the
studs or guides 15, to elevate the edges of the covering material while the wire is
embedded therein as described.
Eleventh. The combination with the guide bar 3, grooved wheel 5, and closing
pressure rolls 9, of the two pairs of studs or guides 15, 16 for elevating the sides of

page_text: the covering strip to vertical or parallel position in preparation for passing between
Baid closing pressure-rolls as explained.
Twelfth The combination of the drawing rolls 14, with covering apparatus
operating substantially as herein set forth.
Thirteenth, The process for covering wire for electrical purposes, substantially as
herein set forth.
Fourteenth. The apparatus for covering wire for electrical purposes, substantially
as herein set forth.
In witness whereof I tho said John Josoph Charles Smith have hereunto set
my hand and seal this Twentieth day of March in the year of our Lord
One thousand eight hundred and eighty three.
JOHN JOSEPH OHARLES SMITH (LIS.)