TH31867A - High-density cable - Google Patents

Abstract

DC60 (09/07/40) Communication cables with special electrical characteristics and meeting combustion requirements for use in conduits. The core consists of one or more twisted pairs of wires with a primary insulation layer made of a suitable material, such as high-density polyethylene. The core is encased in an inner sheath made of low-smoke polyvinyl chloride, as an option. Alternatively, the core may be encased in a core sheath with sufficient electrical properties and combustion/flammable resistance. The inner sheath is then encased in an outer sheath made of a material with excellent heat/flame resistance, but possibly less than maximum electrical properties, such as thermoplastic halogenated polymers, for example, polyvinyl fluoride. Many cores may be encased in a specific inner core sheath and/or the inner sheath may be encased in an outer sheath. Communication cables with special electrical characteristics and meeting combustion requirements for use in conduits. Core wiring consists of one or more twisted pairs of wires with a primary insulation layer made of a suitable material, such as high-density polyethylene. The core is encased in an inner sheath made of low-smoke polyvinyl chloride, as an option. Alternatively, the core may be encased in a core sheath with adequate electrical properties and flame resistance. The inner sheath is then encased in an outer sheath made of a material with excellent heat/flame resistance but possibly less than maximum electrical properties, such as thermoplastic halogenated polymers (e.g., polyvinyl fluoride). Many cores encased in specific inner core sheaths and/or inner sheaths may be encased in an outer sheath.

Claims (38)

1. A communication cable consists of a core containing at least one transmission medium and a plastic sheath enclosing at least one such medium as the primary insulation layer. An outer sheath surrounds the core and is made of polymer, and a middle layer is installed between the core and the outer sheath to physically and electrically separate them. This ensures stability at high temperatures and appropriate electrical characteristics. 2. Communication cables as described in item 1, where the outer sheath is made of thermoplastic fluorocarbon polymer. 3. Communication cables as per item 2, where the outer sheath is made of polyvinylidene fluoride. 4. Communication cables as defined in clause 1, where at least one of the transmission media consists of a twisted pair of wires, and where the plastic material used as the primary insulation on each wire in this twisted pair is polyolefin. 5. Communication cables as per item 4, where the polyolefin material is high-density polyethylene. 6. Communication cables as per Clause 5, where the first layer of high-density polyethylene insulation is a foam/face structure. 7. Communication cables as per item 1, in which the middle layer material consists of an inner sheath. 8. Communication cables as per clause 7, where the inner sheath is made of low-smoke polyvinyl oxide. 9. Communication cables as per item 1, in which the material consists of a sheath and a core. 10. Communication cables as per clause 9, where the core sheath is made of a material selected from a group consisting of polyimide, polyamide, and/or modified polyimide. 11. Communication cables as per clause 10, in which the shielding around the core is wrapped longitudinally. 12. Communication cables as per clause 10, where the shielding around the core is twisted around it. 13. Communication cables as per clause 9, in which the middle layer material consists of both a core sheath and an inner sheath. 14. Communication cables as per clause 13, where the middle layer material is made of a selection of materials from the group consisting of polyimide, polyamide, and/or modified polyimide, and the inner sheath is made of low-smoke polyvinyl chloride. 15. The communication cable referred to in clause 1, where the transmission medium consists of numerous twisted pairs of wires, with a plastic material used as the primary insulator surrounding each wire in these twisted pairs. 16. Communication cables as specified in Clause 15, where the outer sheath is made of thermoplastic fluorcarbon polymer. 17. Communication cables as per clause 16, where the outer sheath is made of polyvinylidene fluoride. 18. Communication cables as specified in Article 15, where the plastic material used as the primary insulation layer on each wire in a twisted pair of wires is polyolefin material. 19. Communication cables as per clause 18, where the polyolefin material is high-density polyethylene. 20. Communication cables as per clause 19, where the first layer of high-density polyethylene insulation forms a foam/face structure. 21. Communication cables as per clause 15, in which the middle layer material consists of an inner sheath. 22. Communication cables as specified in clause 21, where the inner sheath is made of low-smoke polyvinyl chloride. 23. Communication cables as specified in Article 15, in which the middle layer material comprises both the sheath and the core. 24. Communication cables as per clause 23, where the core sheath is made of a material selected from a group consisting of polyimide, polyamide, and/or modified polyimide. 25. Communication cables as per clause 24, in which the sheath around the core is wrapped longitudinally. 26. Communication cables as per clause 24, in which the shielding around the core is twisted around the core. 27. Communication cables as specified in Clause 15, in which the middle layer material consists of both a core sheath and an inner sheath. 28. Communication cables as per clause 27, where the core sheath is made of a material selected from a group consisting of polyimide, polyamide, and/or modified polyimide. 29. Communication cables as specified in clause 28, where the inner sheath is made of low-smoke polyvinyl chloride. 30. The cables used for communication under clause 15 shall include numerous cores, each containing numerous twisted pairs of wires, which are successively surrounded by numerous inner sheaths, which in turn are outer sheaths that enclose and wrap around these numerous inner sheaths. 31. Communication cables as specified in clause 31, in which the inner sheath is made of low-smoke polyvinyl chloride. 32. Communication cables as per clause 31, where the outer sheath is made of thermoplastic halogenated polymer. 33. Communication cables as per clause 32, in which the thermoplastic halogenated polymer is a thermoplastic fluorocarbon polymer. 34. Communication cables as per clause 33, in which the thermoplastic fluorcarbon polymer is polyvinylidene fluoride. 35. Communication cables shall consist of a core consisting of at least one twisted pair of twins and a polyolefin primary insulation layer surrounding at least one such twisted pair; a sheath enclosing the twisted pairs and the said polyolefin primary insulation layer and made of a material of choice from a group consisting of polyimide, polyamide, and/or modified polyimide; and an outer sheath enclosing the core sheath and made of polyvinylidene fluoride. 36. Communication cables consist of a core made of at least one twisted pair of twins and a primary insulation layer of polyolefin surrounding at least one such twisted pair; a sheath that encloses the twisted pairs and the aforementioned polyolefin primary insulation layer and is made of a polyimide film; and a outer sheath that encloses the aforementioned sheath of the core and is made of low-smoke polyvinyl chloride. 37. Communication cables as specified in clause 37, where the primary insulation material of such polyolefin is high-density polyethylene. 38. Cables used for communication under clause 37 where the polyimide film has a thickness of 1 to 5 millimeters (Clause 38, 3 pages, 3 figures).