Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
ROPE OR CABLE AND METHOD OF MAKING SAME
The present invention relates to a novel rope or
cable construction and the method of making same. Although
the making of rope or cable is an ancientart,modernmaterials
and methods have improved the art substantially. The
following U.S. patents and what they describe are
illustrative of the background for the present invention and
represent the closest prior art of which applicant is aware:-
Buhler patent #2,107,567 dated November 23, 1934,
for Finishing Welt. A decorative rope formed of a central
core, twisted or straight, and a cover, woven or braided.
Thompson patent #2,146,275, dated February 7,
1939, for Impregnated Woven Sheath. A core of parallel yarns
is bonded at intervals, and a nonporous layer around the
core and an outer coating of neoprene are formed to prevent
the instrusion of moisture.
3uhler patent #2,360,106, dated October 10, 1944,
for Joint Packing. A rope with a resilient core is bound in
a woven or braided cover and used for packing.
Poirier et al. patent #2,737,075, dated March 6,
1956, for Cord Structure. A plurality of casings are
successively braided over the core and applied loosely to
permit slipping and thus allow flexing of the cord.
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Creve patent #2,985,056, dated May 23, 1961, for
Line and Method of Manufacture Thereo. A core of animal
fibers and synthetic fibers are twiste~ together, moistened
to bind them and provide high tensile strength, and then
covered with strands of braided synthetic fibers to form a
string for a tennis racquet or the like. The strands and
core are bonded by a synthetic material which dries hard.
The braided cover is for the purpose of good wear.
Morieras patent #3,265,809, dated August 6, 1966,
for Cables with Bonded Organic Filamentary Insulation. A
central conductor is surrounded by bonded, parallel twisted
yarns of insulating fibers impregnated with latex. Then a
sheath is braided about the core. The assembly is sized
through a die and oven-cured. The rope is intended to afford
good insulating qualities and tensile strength.
Durkee et al. patent #3,457,717, dated July 29,
1969, for Plastic Coated Cable and Method of Making Same.
Strands of wire are aligned in several cables, bundled into
a larger cable, and spaces in the outside of the bundle
receive smaller cables to tend to ~ill in and smooth the
outer periphery. Molded plastic strips with butt or lap
joints fill the outer irlterstices. Caulking of a soft plastic
material is then applied. A thin binder of glass adhesive
tape holds the strips in position, and then a spiral wrap
of nylon or other plastic is followed by a layer of acrylic
resin which is then cured. This cable is intended for
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suspension-bridge cabling, the outer cover providing a
moisture barrier.
~ood patent #3,911,785, dated October 14, 1975,
for Parallel Yarn Rope, and Hood divisional patent
#4,019,940, dated April 26, 1977, for Method of Manufacturing
Parallel Yarn Rope. A plurality ofslightly twisted filaments
are paralleled together and bonded by a binder disposed
predominantly on the surface of the yarns to form a core.
A nonporous layer of flexible, water-impervious insulating
material surrounds the core. A jacket is braided over the
insulating material, and a final coating of neoprene
completes the rope. Applying the binder only on the surface
of the yarns is intended to aid flexibility; the rope is
intended to have good insulation qualities.
Phillips patent #3,936,336, dated February 3,
1976, for Method of Forming Reinforced Plastic Articles
Utilizing Openwork Tubes. A glass fiber tube, such as a
braided covering, is charged with a core of resin-impregnated
fibers. The tube is tensed to reduce the tube diameter,
impregnate the core, and cover with excess resin. Then the
resin is cured to produce a strong rod of reinforced plastic
and may be tensed when bent to provide a curved shaped
article. ~
~ Morieras patent #4,312,260, dated January 26,
1982, for Flexible Cable. A core lS formed of a bundle of
parallel threads. The threads are impregnated at spaced
intervals at a nonperpendicular angle to the axis of the
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parallel fibers, thus systematically mixing the overlaps,
that is, mixing systematically the impregnated, infle~ible
portions and the nonimpregnated, flexible portions of the
core. The core is surrounded by a bonded outer layer over
which a cover is braided. The spacing between the impregnated
portions is to afford some flexibility to the final product,
whereas the impregnated portions are intended to give tensile
strength.
Also of interest are Kippan U.~. patents #3,415,919
dated December 10, 1968; 3,446,002 dated May 27,1969; and
3,551,280 dated December 29, 1970; which show twines having
a core comprising a bundle of untwisted monofilaments with
a wrap or casing applied to the core to comple~e the twine.
A plurality of parallel filaments are aligned and
compacted to form a core. The core is then wrapped to form
a uniform jacket that is torsionally stable. Urethane or
other plastic material is applied to the jacket to penetrate
the wrapping without penetrating the core. Then the urethane
or other material is cured. The rope or cable thus has a
core of parallel filaments free to move within the urethane
jacket. In some cases, an outer sheath, such as a braided
sheath, may be used, with or without the urethane
impregnation.
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Therefore, in accordance with a first aspect
of the present invention ~here is provided a method of
making rope or cable comprising the steps of: aligning
and compacting a plurality of filaments under tension to
form a core; spirally wrapping the core with one or more
tapes so as to completely cover the core; and applying
an outer cover to the wrapped core.
In accordance with a second aspect of the
invention there is provided a rope or cable comprising:
a core of aligned, compacted, parallel filaments, each
independent of the others; a jacket around the core
comprising one or more tapes helically wound around the
core so as to completely cover same; and an outer cover
surrounding the wrapped core.
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DESCRIPTION OF THE DRAWING
The various objects, advantages, and novel
features of the invention will be more fully apparent from
Sthe following detailed description when read in connection
with the accompanying drawing in which like reference
numerals refer to like parts and in which:-
Fig. 1 is a highly schematic representation
illustra~ing a method embodying the invention to make a rope
10of the invention;
Fig. ~ is an enlarged schematic sectional view
along lines 2-2 of Fig. 1 showing bundles of Eibers being
positioned by a registration plate in preparation for a core
of the rope or cable being manufactured;
15Fig. 3 is a sectional view along lines 3-3, not
to scale, of Fig. 1 showing one method of wrapping the core;
Fig. 4 is an enlarged sectional view along lines
4-4 of Fig. 1 illustrating the inner appearance of a wrapped
core before curing;
20Fig. 5 is an enlarged fragmentary side view of the
rope or cable of Fig. 4 with a braided sheath being applied
thereover;
Fig. 6 is a fragmentary enlarged sectional view
along lines 6-6 of Fig. 1 illustrating the appearance of the
25finished urethane impregnated rope or cable made by the
method of the instant invention; and
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Fig. 7 is an enlarged fragmentary side view of the
rope or cable of Fig. 6 with a braided sheath being applied
thereover.
DESCRIPTION OF T~E INVENTION
Referring to Fig. 1, a plurality of filaments 8
are organized into a group of parallel, preferably untwisted,
filaments in a zone 10, dried in a zone 11, compacted into
a core 7 in a zone 12, wrapped with ribbon to form a jacket 9
in a zone 13, and further compressed or compacted in a
zone 14. Then a plastic material 19, such as urethane, is
applied in a zone 15 and the material 19 compressed into the
wraps of jacket 9 in a zone 16 to penetrate the wraps only
and not the filaments 8, which are left free to move relative
to each other. Finally the urethane or other material 19
which penetrated the jacket 9 is cured in a zone 17 to provide
a completed rope or cable 18. In the organizing zone 10,
filaments 8 are drawn from supply source 21 and thence through
apertures 2~a of a registration plate 22 (Fig. 2, not to
scale). The registration plate 22 is only schematically
indicated. The number of apertures 22a may be much greater
than the number shown and symmetrically arranged about an
axls o ~lign the fl~aments 8 into substantial parallelism.
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Each supply source 21 may eed a non-twisted yarn
with many filaments 8, and each aperture ma~ pass a like
plurality of filaments 8 from the source 217 After leaving
the plate 22, the filaments 8 advance into a drying zone ll
where they pass through a drying chamber 23 heated by any
suitable heat source 24.
After drying, the filaments 8 are compacted by a
die 26. Means, such as a pair of rollers 25, the drive means
for which is not shown, serve to draw the core 7 of the
filaments 8, now compacted into compressed core 27, through
the die 26, and also serve to draw the filaments 8 from the
supply source 21 over the tensioning devices 20 and through
the plate 22.
The compacted core 27 of filaments 8 is now wrapped
in a zone 13 to provide the jacket 9. In this exemplification,
the jacket 9 is applied by winding or twisting around the
compacted core 27 from respective spools 28a and 28b narrow
ribbons or tapes 29a and 29b in opposite directions ~see
arrows, Fig. 3) so the parallel filaments 8 are not
inadvertently or undesirably twisted. The tension for each
spool may be controlled by means of a friction release (not
shown) applied to the respective spools 28a and 28b. The
higher the friction, the more force is required to draw the
ribbon from the spools 28a, 28b: and the greater the tension
as the ribbons 29a and 29b are wound upon the core, the more
tightl~ the core is compressed at this stage. Mechanisms
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for such wraps are known, and th~t of Figs. 1 and 3 is only
schematically illustrated.
Preferably the ribbons 29a, 29b are ribbons of
absorbent material so that the later-applied urethane 19 may
readily impregnate the ribbon, but not penetrate into the
core. Also, more than the two layers of ribbons 29a and 29b
may be applied if desired, i.e., there may be more than two
spools used at a time, but preferably an even number to avoid
accumulatinga twistin the filaments belng wrapped. Although
a knitted fabric is preferred for the ribbon, other ribbons,
such as those of woven or nonwoven fabrics or synthetic
films,may also be used. For simplicity, speed ofapplication,
and low cost, I prefer to use ribbons of narrow polyester
knit fabric, and helically wrapped in opposite hand about
the core. The degree of overlap of the ribbons may also be
controlled to provide a desired number of layers at a point
along the axis. Although it has been found preferable to
wrap the core with a like number of ribbons in each direction,
it is possible to provide an effective wrap comprising one
or more ribbons spirally wound around the core in the same
direction, so long as the core is completely covered by the
wrap.
The rope or cable 30 comprising the compacted
core 27 of filaments 8 and the wrap 29a, 29b now passes into
zone 14 for further compacting to a specified size by passage
through a die 32. The rope 30 is drawn from the rollers 25
and past the wrapping zone 13, and thence through the die 32
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by means such as rollers 33 and 34, the drive means for which
is not shown.
From compacting zone 14 the rope or cable 30 enters
at zone 15 a urethane or other material bath 35 in a tank 36
which may be replenished as needed from a pipe 40. The
material may also be extruded directly onto the rope or cable.
The rope, coated with such urethane or other
material, is fed through a die 38 in a zone 16. The die
Eorces the urethane or other material to impregnate jacket 9
of the rope. At the same time, the excess coating is wiped
off and returns to the bath 35. The die 38 aperture is
selected to force impregnation of only the jacket 9 with
urethane or other material, and not to have urethane or other
material penetrate the core or inner bundle o~
monofilaments 8, which are left free.
Preferably the filaments 8 are not penetrated at
all, or, at the very least, only the very outermost ones of
the bundle. On the other hand, it is not essential to
completely impregnate all the layers of the ribbon to its
complete depth. I prefer to have the urethane penetrate
substantially completely the layers of ribbon, and not at
all the filaments 8. The impregnated rope is pulled through
the die 38 by means such as rollers 39r the drive means for
which is not shown. A layer of urethane 19 may be left on
the outer surfaceof the rope or cable for abrasion-resistance
and moisture-barrier purposes.
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Then the rope or cable is advanced into a curing
or heating zone 17 where it is cured - for example, in an
oven 42 heated by a suitable heat source 43. Means such as
a pair of rollers 44 draw the rope through the oven 42 from
5the rollers 39 and discharges khe completed rope 18, which
now may be wound onto a suitable spool 46. As it is being
wound on the spool 46 or at any convenient time after leaving
the curing oven 42, indicia 47 may be marked on the rope so
that the length of rope withdrawn or used may be readily
10ascertained. In Fig. 6 the finishedrope or cableis indicated
in cross section, and outer ribbon 29b and inner ribbon 29a
are indicated as penetrated with the cured urethane or other
material by stippling. The number of filaments may be in
the thousands and are illustrated as in Fig. 4. The filaments
15are left free; that is, they are non-adhered to each other
or to the jacket 9 impregnated with the cured urethane.
It will be understood that while the use of the
urethane or the like coating is preferred, in some
applications it may be desirable to substitute an outer
20sheath 48 that could be braided, extrudedor otherwiseapplied
directly to the jacket 9 as shown in Fig. 5. On the other
hand, in some cases it may be desirable to apply such an
outer sheath over the jacket 9 after the latter has been
impregnated with urethane or the like, as shown in Fig. 7.
25Furthermore, after the braided sheath 48 has been applied
to the rope of either FigO 5 or Fig. 7, it may in some cases
be deslrable to impregnate the sheath with urethane or the
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like, which can be accomplished by any suitable means, such
as by passing through another tank similar to that shown
at 36 in Fig. 1.
As an example in one successful and preferred
embodiment, I provide filaments 8 of polyest~r, six denier
per filament, and there may be about 33,000 filaments 8 in
the core. The die 26 opening or aperture is about .185 inch
diameter. When the ribbons 29a, 29b are drawn from the
spools 28a, 28b, their tension is about twelve pounds. The
angle of wrap is about 35, and the overlap about 40 per
cent. Thus, there are about four total number of layers or
ribbons at any point along the rope 30. The heat of the
drying chamber should be gentle, preferably about 200 F.,
although this is not critical. The opening for the die 32
is about .250 inch diameter. The ribbons 29a and 29b are
polyester and are about one inch wide. The temperature of
the curing oven is about 200 F. The resultant rope or cable
is about .250 inch outer diameter, and the wall of the
jacket 9 after impregnation and curing is about .080 inch
in thickness. Rope or cable of other outer dimensions may
be made by the process. The urethane-impregnated jacket
provides improved abrasion and moisture resistance.
A rope or cable of the invention has many
advantages. No heat seal or end taping is required when the
rope is ~ut, because it does not unravel. It may be
manufactured to close tolerances; and the rope lends itself
to various standard end terminations. For example, an eye
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may be easily formed at either end of the roope and secured
by any desirable means, such as a metal sleeve, or the rope
may be spliced.
The rope or cable is excellent or use in
construction and placement of concrete revetment mats. It
is highly resistant to ultraviolet rays, to most chemicals,
and to biological conditions encountered at most deployment
sites for that purpose. The rope or cable is also highly
useful in conditions where a high dielectric constant is
desirable. Also, the rope has high tensile strength. For
e~ample, a one-quarter-inch size outer diameter has a tensile
strength of 35~ pounds; a 5/16 inch outer diameter size has
a tensile strength of 7000 pounds; and a half-inch outer
diameter size has a tensile strength of 15,000 pounds.
Lengths are easily provided of up to 25,000 feet without a
core splice.
~ecause of the parallel filaments of the core being
free, that is, not adhered or bound to each other, the rope
or cable has a high flexibililty compared to other ropes of
li~e strength. The tightly wound jacket holds the core
firmly ~ogether under compression, eliminating need for any
adhesive bond of the fibers, and eliminates the necessity
of braiding a cover over the core, although such a cover may
be applied over the wound jacket. The cured urethane or
other material cover holds the jacket and core together and
allows the rope or cable to be cut without unraveling. No
binding, heating or melting is required to prevent
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unraveling. The cured coating, as noted above, is abrasion
resistant and creates a moisture barrier. Unlike ropes not
resistant to moisture, the invention may be used with minimal
risk of creating a conductive path near high-voltage lines
and towers.
Double-braided rope is relatively flexible and
strong, but it tends to hold moisture, which tends to make
it conductive when wet. There is also an undesirable
elongation of double-braided rope under tension. These
faults are absent in the rope or cable of the present
invention, which is resistant to moisture, is still flexible
and strong, and exhibits minimum elongation under tension,
primarily because of its non-twisted core.
The method of the present invention can produce
rope or cable more rapidly than the prior methods. The rope
or cable of the invention can be produced at a rate, for
example, of about 40 feet per minute, and if desired at
greater speeds, up to about 80 feet per minute, with no
spooling or twisting, with only one machine, and with a waste
factor about equal to, or even less than, one per cent, far
better than current speeds and production losses.
By varying the tension of the cover wrap, the size
of the compacting die, and the hardness of the urethane or
other material, varlous degrees of flexibility, size and
tensile strength can be obtained for the rope or cable of
the present invention without the necessity of changing
production speeds, machinery, or feed set-ups. These factors
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contribute to a low production cost and make possible a low
price for the rope or cable of the present invention.
While there is shown and described herein certain
specific structure embodying the invention, it will be
manifest to those skilled in the art that various
modifications and rearrangements of the parts may be made
without departing from the spirit and scope of the underlying
inventive concept and that the same is not limited to the
particular forms herein shown and described except insofar
as indicated by the scope of the appended claims.
