Method and Apparatus for a Composite Cable Safety Net
A net is formed by joining cables which are over-knitted with cord. A cable may be made of wire or stainless-steel cable. A composite cable is a cable that is over-knitted with cord to form a composite cable. The cord may be made of fibrous material and in some embodiments is made of aramid fibers. Adjacent composite cables are joined at regular intervals to form a net. In some embodiments, composite cables are composed of cable with an over-knitted cord, inter-knitted at junctions that are spaced at regular intervals to form a net. The individual cables are over-knitted with cord and the junctions are formed as the over-knitted cords are inter-knitted.
The present disclosure relates to cables, wires, methods of manufacture and uses thereof.
BACKGROUND OF THE INVENTIONSafety netting and fences arranged around high-rise buildings protect construction workers and prevent debris from falling to the ground. Nets and fences are constructed of linked wire, cable or metal fibers. Nets of combined at intervals cord generally have at least one stainless steel line surrounded by aramid fibers. Aramid fibers, also known as aromatic polyamide fibers, are a class of heat-resistant, strong synthetic fibers used in high-strength applications such as ballistic-rated body armor and marine cordage.
Suicide-prevention barriers may be constructed of stainless steel-netting or fencing, in a pattern that prevents climbing and also to catch objects falling from construction heights. A challenge in the design of suicide barriers is to provide a structurally sound and vandal-proof deterrent while maintaining the visual appeal of the building or structure onto which the barrier is mounted
Technical textile-production is a rapidly developing industry, with textile structures replacing expensive, heavy or technically inferior constructions.
Nets in the current state of the art are now engineered with metallic cores and composite materials, using new warp-knitting and stitch-bonding techniques.
“Cord” refers to any textile strand, twine, rope, line or thread. In the context of this embodiment, the cord is used in a novel knitting method to produce a warp-knitted tubular fabric.
SUMMARYA net of composite cable joined at intervals is made of various materials, each of which is difficult to cut. At its core is a cable made of metal wire, cable or other dense material around which is knitted a strong cord. The knitted cord is of a material that requires a sharp blade to sever, while the dense cable requires a bolt cutter or similar tool that crushes the dense material to sever it. Together the cable and over-knitted cord make a strong composite cable that is difficult to cut.
The over-knitted, composite cables are attached to each other at intervals to form a net in one of various ways, described below.
The cord is composed of fibrous material, and in some embodiments is aramid fibers, used to form a warp-knitted tubular fabric that surrounds a cable. Loops are formed continuously on a needle, with the loops surround a cable and are further interlaced at intervals to form a net.
In one embodiment, adjacent, cables are joined at intervals to form a net with hexagonal or similarly shaped openings.
Cable may have a wire core made of stainless steel. One skilled in the art understands that a stainless-steel core may be composed of a solid wire or of a twisted or braided cable. Around this core, fibers may be spun, knitted, braided or wrapped. Cable is over-knitted with cord to form a composite cable. In some iterations, a sheath surrounds the composite cable.
In an embodiment, cord is knitted over the cables to strengthen the cables. This cord may be made of aramid fibers. In another iteration, a cable core is a bundle of twisted wires surrounded by, or “over-knitted” by knit cords. In some embodiments the cable core is of twisted or braided stainless steel, and the knit cords are made of aramid fibers. The combination of cable core and surrounding knitted cord provides a composite cable that can be attached at intervals to form a strong net that is difficult to cut. In some embodiments at least one outer layer of sheathing covers each over-knitted, composite cable.
An attempt to cut such a cable with a lever-driven cutting tool (for example, with wire- or bolt-cutters) pushes the cable's fibers away from the cutting tool, preventing cutter blades from acquiring sufficient purchase to cut both the metal core and the over-knitted cord. Wire cutters and bolt cutters are designed to compress metal. Using them on metal forces the metal to separate. Fibrous materials cut best with a sharp blade that severs the fibers. To cut the composite cable of the disclosure, one would need to cut the over-knitted cord with a first tool, and then attempt to use a second tool to sever the metal cable core. Time and effort to do so would deter an individual from attempting to cut through a net made of this combination of materials.
In another iteration, a cable core is composed of a metal cable of twisted wires. The metal cable, over-knitted with cord, and further sheathed in an additional cover (sheath), forming a composite cable. In some embodiments, the metal cable is composed of twisted or braided stainless steel, and the over-knitted cords are aramid fibers. The combination of cables and knitted fibers and sheath provides a composite cable that can be attached at intervals to form a net of a strength that is difficult to cut. As with the above iteration, an attempt to cut such a composite cable with a cutting tool would push rather than cut the fibrous sheth and over-knitted cord. As in the first iteration, one would need to cut the sheathing, knitted fibers, and metal-cable core with two or more tools. Time and effort to do so would deter an individual from attempting to cut through a net made of this combination of materials.
In one application, a net is made out of a set of adjacent cables that are over-knitted with cord and cords are inter-knitted, also referred to as interlaced, forming junctions thus providing a net.
One skilled in the art understands that cords knitted over cables in a seamless tubular warp-knitted fabric on single cables may be further knitted over junctions, as demonstrated in junction 130 of
Although “fibers” are referred to as “aramid fibers,” one skilled in the art understands that various fibers, natural and synthetic, may be used for various purposes. Cable cords may be stainless-steel cords, however one skilled in the art understands that various materials, including metal cables, rope or line, or composites of these may be used.
Claims
1. A composite cable comprising:
- at least a first wire; and
- said first wire over-knitted with at least a first cord; wherein
- said composite cable provides a strength of both the cord and wire and requires cutting both the cord and wire to sever the composite cable.
2. The composite cable of claim 1 further comprising:
- at least a second wire over-knitted with at least a second cord; and
- said second cord inter-knitted with said first cord at regular intervals; wherein a net is formed.
3. A composite cable comprising:
- at least a first wire combined with at least a second wire to form a cable; and
- said cable over-knitted with at least one cord; wherein
- said composite cable provides a strength of the first wire, the second wire and the cord and requires cutting both the cord and the first wire and the second wire to sever the composite cable.
4. The composite cable of claim 3 wherein:
- said at least one cord is knitted over said cable in a seamless tubular warp-knitted fabric.
5. The composite cable of claim 3 wherein:
- said first wire and said second wire are comprised of metal; and
- said at least one cord is comprised of a fibrous material.
6. The composite cable of claim 3 wherein:
- said first wire and said second wire are comprised of stainless steel; and
- said at least one cord is comprised of aramid fibers.
7. A net comprising:
- a plurality of adjacent composite cables, each having a core; and
- a knitted cord surrounding each said core; and
- said knitted cord inter-knitted at a first set of regular intervals with a knitted cord of at least one adjacent composite cable, forming a net.
8. The net of clam 7 wherein:
- alternate adjacent cables inter-knitted at a second set of regular intervals that are offset from said first set of regular intervals; wherein
- a net is formed having voids with hexagonal perimeters bounded by said plurality of adjacent composite cables.
9. The net of claim 7 wherein:
- said core is comprised of twisted metal cable: and
- said knitted cord is comprised of fibrous material.
10. The net of claim 7 wherein:
- said core is comprised of twisted stainless steel cable; and
- said knitted cord is comprised of aramid fibers.
11. The net of claim 7 further comprising:
- said core is comprised of braided stainless steel cable; and
- said knitted cord is comprised of spun aramid fibers.
12. The net of claim 7 further comprising
- a first sheath, surrounding said core sheathed in knitted cord; wherein
- said sheath expands to cover both composite cables where they join at regular intervals.
13. The net of claim 12 further comprising
- a second sheath surrounding said first sheath; wherein
- said first sheaths are knitted together with said second sheaths at said first set of regular intervals.
14. A method of manufacturing the net of claim 7, the method comprising:
- knitting a first cord over a first cable; and
- knitting a second cord over a second cable; and
- inter-knitting said first cord with said second cord at regular intervals along said first cord and said second cord; and
- repeating the aforementioned steps with a plurality of cords and cores; wherein a net is manufactured.
15. The method of claim 14 further comprising:
- knitting said first cord over said first cable; and
- forming a seamless tubular warp-knitted fabric that surrounds said first cable; and
- knitting said second cord over said second cable; and
- forming a seamless tubular warp-knitted fabric that surrounds said second cable.
Type: Application
Filed: Jul 26, 2023
Publication Date: Feb 8, 2024
Inventors: Gerhard Komenda (Ghent, NY), Lukas Scheurer (Providence, RI)
Application Number: 18/359,698