IMPROVEMENTS IN THE MANUFACTURE OF COVERED OR INSULATED WIRES AND IN APPARATUS THEREFOR
Year: 1885

page_text: I ALFRED JULIUS BOULT of 323 High Holborn, in the county of Middlesex,
Engineer do hereby declare the nature of this invention for "IMPROVEMENTS IN
THE MANUFACTURE OF COVERED OR INSULATED WIRES AND IN APPARATUS
THEREFOR," (a communication from Joseph Drew Thomas of New York, in the
United States of America, Manufacturer) and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
A prominent feature of this Invention consists in covering wire with two or
more successive adherent strips or tapes wound on spirally, the second tape being
wound at a reverse inclination to the first so that the seams of one tape "break
joints" with the other tape and lie at nearly right angles to each other, whereby a
very strong and impervious covering is produced.
Another feature of this improvement consists in employing tapes or strips of
fibrous material coated with soft rubber or equivalent material before they are
applied to the wire, whereby the rubber coated tapes when wound about the wire
as described adhere firmly to the wire, and to each other, and when the covered
wire is subsequently vulcanized these coatings become fixed thereon in a very firm
and permanent manner, forming a perfect insulating and waterproof covering
thereon, having great tenacity by reason of the spirally over-crossing fibrous webs
or tapes.
It is preferable to saturate the first tape with a thin solution of vulcanizable
rubber, and also to coat its inner face with a film of rubber so as to form an adherent
and insulating layer of rubber next to the metallic surface of the wire, while the
outer surface of the same tape is provided with a thin film of rubber to better
adhere to the second tape which is wound over the first.
This second tape is saturated like the first and also provided with a thin film of
rubber on its inner surface to better adhere to the rubber film on the outer surface
of the first tape, while the outer surface of the second tape is left plain or free from
plastic compound. It is also preferable to prepare this outer tapé by charging it

page_text: with incombustible material so as to be fireproof and uninflamable, so that
while the tape may be charred by contact with flame it will not catch fire or
inflame.
4
The fibrous tapes or strips mentioned may be regularly woven tapes of proper
width, or may be made from any other woven fabric cut into strips or from felt or
paper.
Instead of rubber any equivalent plastic or insulating material may be used but
a soft vulcanizable rubber is much preferable as described.
Instead of covering the naked wire directly with the two reversely wound tapes,
as described the naked wire may first be coated with a covering of soft vulcanizable
rubber applied preferably in the form of two longitudinal strips which are pressed
and united around the wire by feed rollers in the manner shown in a former
American patent N° 271750 of 1883. It is generally preferred to employ this
triple coating, and it forms part of the present invention, but the first rubber coat
may be omitted, without departing from the most essential features of the present
system.
The mechanism employed for covering the wire according to the above system is
shown in the drawing annexed and forms part of this invention, as will be now
described.
Figure 1 of the drawings gives a longitudinal or side elevation of this improved
machine, and Figure 2 a plan view thereof. Figure 3 is a front elevation of the
first feed rollers which apply the preliminary soft rubber coat and Figure 4 is a
section at the junction of the rollers. Figure 5 is a sectional detail of the tape
bobbin and its spindle. Figure A gives an end view of the wire and the rubber
strips previous to entering the first rollers. B represents an enlarged side view of
the wire when passing between the first rollers with the rubber strips applied
thereto. C represents a cross-section of the wire after receiving the rubber cout.
D is a cross-section after receiving the first tape, and E a cross section after
receiving the second tape..
In the Drawings a. a. indicate the bed or table of the machine, at the front end
of which is arranged the first set of feed rollers n. n¹ which may be adapted to
simply seize the naked wire and force it into the machine or to apply the preliminary
rubber coat thereto and feed in the wire at the same time, the latter being assumed
in this case and fully shown in the drawings. At the rear end of the machine is:
placed the second or main set of feed rollers e. e¹ e which act to pull the wire
through the machine and perform the most positive feeding action on the wire.
The rollers of both sets are of course positively geared together and mounted in
adjustable bearings in the manner usual with rollers, and each set is also provided
with driving pulleys p. pl.preferably of similar size to receive driving belts whereby
power is imparted to simultaneously revolve the rollers, which should rotate at
similar speeds. The pulleys p. p¹ may be changed and varied in size when different
speeds are required for different sizes of wire, as will be readily understood.
Bebind the first roller n. n. a fixed upright stock or bearing b arises from the
table of the machine, and in this bearing is journalled a hollow rotary spindle c.
provided with a pulley d. to receive a belt whereby the spindle may be rapidly
revolved as indicated. At about the middle of the table in front of the main.
feed-rollers e. e. is mounted a second upright b¹ with a hollow rotary spindle c¹ and
pulley d¹, similar to the first set. The bores of the hollow spindles c. c' are in line
with each other and with the junction line of the feed rollers n and the lower pair
of, feed rollers e. e. so that a naked wire f may be passed centrally through each of
the spindles and grasped between the feed rollers, which being set in motion will
draw the wire at any desired speed through the spindles while the spindles are
revolved about the wires. From the pulley of each spindle an arm g, projects on
the end of which is sustained a bobbin h. h. which contains coils of tape prepared
as. before described. The axes of the bobbins are jointed to the end of the.
arms g as seen in Figures 1. 2 and 5 and are provided with clamp nutsk whereby
the bobbins may be set at the proper inclination to the wire as will be understood

page_text: from the drawings. A proper frictional tension may be put upon the bobbins by
the thumb-nuts.l. l. which will press the friction springs m. m. against the upper
side of the bobbins, as will be understood.
Where the first rollers m. n are employed to apply the preliminary rubber coat
to the naked wire the rollers will be formed as shown in Figure 3 with forming
grooves r. adapted to the size of the wire with its rubber coat, said grooves having
knife like or cutting edges s, while relief grooves s¹ are formed on either side of the
knife edges. These knife edges and relief grooves are shown in the said former.
patent, and no novelty is therefore claimed therein. Above and below the roller n
is mounted a large bobbin t. t' on which is wound the soft rubber strips x. x. to be
applied to the wire said bobbins having a grooved hub over which a weighted cord
passes, as shown, to keep a proper brake or tension on the bobbin which tension
may however, be effected in any other suitable way.
The naked wire passes from the reel u on which a suitable tension is maintained
similar to that on the bobbins t, as illustrated, and the wire in being led from the
reel passes first through a guide or draw plate fl and thence enters the grasp of
the rollers n. n. between the grooves .r. Simultaneously the rubber strips x.x
are led from the bobbins t. t' over guide plates n¹ n¹ and thence enter the grasp of
rollers above and below the wire and between the grooves r, and the knife edges of
the rollers.
Referring now to Figures 4 and A, it will be seen that the width of the rubber
strips x. x. are each greatly in excess of the semi-circumference of the wire
consequently when the wires and the strips are passed between the rollers the
forming grooves r will compress the strips firmly around the wire while the cutting
edges will cut off the excess on each side, which excess will readily escape into the
relief grooves and will be delivered from the periphery of the lower roller as
sbown at x in Figure 1, these cuttings ¹ being guided off by an attendant and
allowed to accumulate on the floor or in a receptacle thereon, as will be understood.
The strips being soft and unvulcanized will unite perfectly when pressed around
the wire as shown at B and C, and form a uniform circular coating about the wire
as seen best at C.
The rollers n may be heated to promote the union of the rubber strips at their
jointure if desired.
In a former patent N° 1336, dated March 18th 1882, the rubber strips where
shown as about equal to or slightly greater than the semi-circumference of the
wire, whereas in the present case they are greatly in excess of the measure of the
wire. By this means a surplus of strength and material is obtained in the strips
which enable them to resist the tension of the rollers and thus prevent the strips
from stretching longitudinally and contracting laterally and thus failing to properly
encircle the wire as is likely to occur where the strips are not of excessive width,
whereas in the present case the strips are forced to encircle the wire solidly and
with great perfection of circular form, as will be readily appreciated. The large
cuttings which this system required to be removed cause no waste, as they being
soft and unvulcanized-may be worked up and used over again.
It will be seen by reference to the drawings that the two bobbins h. h are set at
opposite inclinations and that the two spindles and bobbins are revolved in opposite
directions and that after the wire passes from the rollers n and receives its
preliminary rubber coating it then passes through the spindles c. c and between
the main feed roller e. e¹. The ends of the tapes on the two bobbins h. h. being
now fastened to the wire and the bobbins set at the proper angle and adjusted to
the proper tension, the motion of the machine is continued by revolving the
pulleys p. pl and d. d in the directions indicated. The wire will therefore advance
through the machine and will receive at first the preliminary coating of rubber at
the rollers n. n. as before described, and immediately after will receive a spiral
wrapping of tape from the first bobbin h which will be wound about the wire in
one direction, and immediately succeeding this a second coat of tape will be
wrapped spirally over the first in an opposite direction from the second bobbin h¹

page_text: •
The speed of the feed rollers e. with relation to the revolution of the spindles c. o¹
will determine the lay of the spiral windings of tape, which are preferably wound
so that the edges overlap, as will be understood.
The tape on the first bobbin h is saturated with a rubber solution, as before
described, and is also coated with a film of soft rubber on its inner side which will
therefore cause the tape to adhere firmly to the rubber coating of the wire or to
the naked surface of the wire as the case may be, when wound about the over-
lapping spiral joints of the tape to adhere firmly and thus cause the tape to be
smooth and adherent as fast as it is wound on, as will be readily understood. The
second tape from the bobbin h¹ is prepared with a film of rubber on its inner face
to adhere to the exterior of the first tape, and is preferably coated or saturated on
its exterior with a fireproofing compound, as before described, so as to render the
exterior of the finished wire fire-proof as before specified.
Where the wire is very thick it is passed between the lower feed rollers e. e¹ but
ordinary sizes of wire are passed in a zig-zag returning curve between and around
the series of rollers and around the top of the upper roller as indicated by dotted
lines in Figure 1. This enables a better grasp to be obtained on the wire and also
acts as a straightening device to remove all kinks from the wire and to deliver the
wire straight upon the winding drum w, on which the covered wire is accumulated,
as will be understood.
After the drum w is filled it is removed to the kilns and subjected to the
vulcanizing heat which fixes the rubber and causes the different layers to become
intimately bound together about the wire, as will be readily appreciated.
It will therefore be seen that the product of this system will be a most effectively
insulated and protected wire having a triple coat of insulating and protecting layers.
The first or rubber coat makes perfect contact with the wire and gives a perfect
insulated and waterproof quality which the two outer layers of tape oppositely
wound add greatly to the insulating and impervious qualities and protects the
inner, rubber layer and renders the entire coating exceedingly strong and flexible
and very durable.
As before stated the inner rubber coat may be omitted and two or more of the
tape windings in reverse directions employed instead.
In this case the rubber films of the tapes might be a little thicker than where
the preliminary rubber coat is used. This would produce an excellent coating, less
expensive than the other and fully as well adapted for a great variety of uses.
Where, however a superior degree of insulation is desired it is preferable to employ
the first rubber coat in connection with the two opposite tape windings, as
described.
The feed rollers e. are preferably made with a steel shaft and an elastic or
yielding periphery formed of vulcanized rubber partly grooved, as indicated at y in
the drawings, thereby forming an elastic grasping surface to seize the wire with a
frictional grasp so that the wire partially embeds itself in the surface of the rollers,
and is grasped in a firm yet elastic manner which does not injure or displace the
coatings of tape in passing between the rollers.
Where it is desired to apply more than two successively wound coatings to the
wire the number of successively arranged bobbins and spindles may of course. be
increased without any change in the principle or action of the machine.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondents I declare that what I claim is
1st The system of covering wire with a fibrous strip or tape coated with soft
unvulcanized rubber wound spirally about the wire and subsequently vulcanized
'thereon.
2nd The system of covering wire by means of two or more adherent strips or
tapes wound successively thereon in opposite directions,

page_text: 3rd The system of covering wire with two successive tapes wound successively
about the wire, the first tape being provided with adherent insulating material to
adhere to the wire, while the second tape is prepared with a dry and non-adherent
exterior.
4th The system of covering wire with two tapes or strips wound successively
thereon, the first tape being of insulating and adherent material, while the outer
tape is not inflammable with a dry and non-adherent exterior, substantially as
herein set forth.
5th A machine for covering wire consisting of two or more hollow spindles
through which the wire is passed and means for revolving said spindles in opposite
directions about the same, a feed roller or feeding device for moving the wire
progressively through said spindles and bobbins set at opposite inclinations on said
spindles, arranged and operating as and for the purpose set forth.
6th The method of covering wire with a triple coating herein described consisting
in first applying a soft rubber coat to the naked wire and thence winding over the
said coat two successive spiral windings of tape each wound in opposite directions
substantially as herein set forth.
7th A machine for applying a triple coat to wire consisting of bobbins adapted
to contain longitudinal rubber strips for encircling the wire with feed rollers
adapted to feed in said strips and wire and unite said strips about the wire, in
combination with two hollow spindles through which the wire is passed after
leaving the rollers, bobbins set at opposite inclinations on said spindles and adapted
to contain covering tapes, and with means for revolving the spindles and bobbins
in opposite directions simultaneously with the feed rollers and wire, substantially
as and for the purpose set fortli.
8th In the art of covering wire with two longitudinal strips united about the
wire by means of grooved feed rollers having cutting edges and relief grooves, the
system of forming said tapes previous to their admission to the rollers of a width
greatly in excess of the circumference of the wire substantially as and for the
purpose set forth.
gth In a wire covering machine, feeding rollers having their grasping surface
formed of vulcanized rubber grooved and thus adapted to grasp the covered wire.
with a firm elastic pressure without injuring the coatings thereof substantially as
set forth.
10th In a wire covering machine the combination with a hollow spindle through
which the wire passes, of a tape holding 'bobbin mounted on said spindle with the
axis of the bobbin jointed thereto and adjustable to different angles thereon,
substantially as and for the purpose set forth..