US4510348A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-shielded, fire-resistant plenum cable
Assignee: Avaya Technology LLC
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Filing: 1983-03-28
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Granted: 1985-04-09
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Expires: 2003-03-28
Abstract
Abstract A relatively small pair size cable (20) comprising at least one insulated conductor (22) is provided with a flame retardant, smoke suppressive non-metallic sheath system (30). The sheath system has a relatively low thermal conductivity and provides a predetermined delay prior to the thermal decomposition of the conductor insulation. It includes an inner layer (31) of an inorganic cellular material which has a relatively low air permeability and two tapes (41, 42) which are wrapped helically about the inner layer with overlapped sealed seams. Each tape comprises a flame retardant thermosetting material. In an alternative embodiment, the heat absorptivity of the sheath system is increased substantially to facilitate the sealing of the seams as the cable is moved along a manufacturing line. This may be accomplished by using an inorganic cellular material which has a relatively high absorptivity or by facing the inner layer or one of the tapes with a material which is heat absorptive.
Inventors
- 👤 Candido J. Arroyo
- 👤 Nicholas J. Cogelia
- 👤 Ralph J. Darsey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:10
CPC Classifications
G; G02; G02B; G02B6/00; G02B6/44; G02B6/4401; G02B6/4429; G02B6/4436; H; H01; H01B; H01B7/00; H01B7/17; H01B7/29; H01B7/295
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
135 words
A cable which resists flame spread and smoke evolution, said cable comprising: a core which includes at least one conductor enclosed in a plastic coating; and a non-metallic sheath system having a relatively low thermal conductivity which encloses said core and which is effective to provide a predetermined time delay prior to thermal decomposition of the conductor coating when the cable is subjected to a relatively high temperature, said sheath system including: a layer of an inorganic cellular material which encloses said core and which has a relativley low air permeability; and a tape which is wrapped about said layer and which comprises a flame retardant thermosetting material, said sheath system in the vicinity of the interface between said layer of cellular material and said tape including a material having a relatively high heat absorptivity.
Claim 2
Dependent Claim
135 words
A cable which resists flame spread and smoke evolution, said cable comprising: a core which includes at least one conductor enclosed in a plastic coating; and a non-metallic sheath system having a relatively low thermal conductivity which encloses said core and which is effective to provide a predetermined time delay prior to thermal decomposition of the conductor coating when the cable is subjected to a relatively high temperature, said sheath system including: a layer of an inorganic cellular material which encloses said core and which has a relativley low air permeability; and a tape which is wrapped about said layer and which comprises a flame retardant thermosetting material, said sheath system in the vicinity of the interface between said layer of cellular material and said tape including a material having a relatively high heat absorptivity.
Claim 3
Dependent Claim
24 words
The cable of claim 1, wherein said sheath system has a thermal conductivity in the range of 0.001 to 0.0001 cal-cm/cm 2 -sec° C.
Claim 4
Dependent Claim
17 words
The cable of claim 1, wherein said layer of inorganic cellular material comprises a woven glass. a
Claim 5
Dependent Claim
18 words
The cable of claim 1 wherein said layer of inorganic cellular material has a relatively high heat absorptivity.
Claim 6
Dependent Claim
32 words
The cable of claim 4, wherein said layer of inorganic cellular material is a woven glass in which an outer surface is faced with a material having a relatively high heat absorptivity.
Claim 7
Dependent Claim
12 words
The cable of claim 4, wherein said layer comprises a nonwoven glass.
Claim 8
Dependent Claim
28 words
The cable of claim 6, wherein said outer surface of said layer is faced with a material having a heat absorptivity in the range of 0.90 to 0.97.
Claim 9
Dependent Claim
24 words
The cable of claim 1, wherein said sheath system includes first and second tapes which are wrapped about said layer of inorganic cellular material.
Claim 10
Dependent Claim
33 words
The cable of claim 8, wherein said first tape is disposed adjacent said layer of inorganic cellular material and an inner surface of said first tape is faced with a heat absorptive material.
Claim 11
Dependent Claim
37 words
The cable of claim 8, wherein each said tape is wrapped helically about the enclosed core so that each turn of said each tape overlaps about fifty percent of a preceeding turn of the same said tape.
Claim 12
Dependent Claim
35 words
The cable of claim 10, wherein each of said tapes has at least a portion of at least one major surface coated with an adhesive that seals the seam and that does not burn prematurely.
Claim 13
Dependent Claim
28 words
The cable of claim 11, wherein an outwardly facing surface of said first tape and an inwardly facing surface of said second tape are coated with an adhesive.
Claim 14
Dependent Claim
20 words
The cable of claim 12, wherein said adhesive has an index of heat absorptivity in the range of about 0.90-0.97.
Claim 15
Dependent Claim
31 words
The cable of claim 13, wherein each of said first and second tapes has at least a portion of at least one major surface coated with a fluorinated ethylene propylene adhesive.
References Cited (Backward Citations)
US2691694A
Cited
US3265808A
Cited
US3425865A
Cited
DE2120152A1
Cited
US3692924A
Cited
US4051324A
Cited
US4134953A
Cited
US4150249A
Cited
US4370076A
Cited
US4151366A
Cited
US4154976A
Cited
US4284842A
Cited
US4327001A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-04-08 | 1988-10-08 | 1989-04-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-04-08 | 1992-10-08 | 1993-04-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-04-08 | 1996-10-08 | 1997-04-09 | $7700.00 | Window Closed / Lapsed |