US4534886A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Non-woven heating element
Assignee: Hollingsworth and Vose Co
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Filing: 1981-01-15
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Granted: 1985-08-13
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Expires: 2001-01-15
Abstract
Abstract An electrically conductive non-woven web for a heating element is formed from a non-woven sheet comprising conductive fibers which is saturated with a dispersion comprising conductive particles. Embodiments adapted for use at low voltages and at household voltages are provided. In a preferred, flame-resistant embodiment, the heating element is a sandwich containing, from bottom to top, a first insulating non-woven sheet comprising polyaramid fibers, an electrically conductive web comprising carbon fibers, polyaramid fibers, and carbon black. A pair of conductive strip attached in electrical contact to the web, and a second insulating non-woven sheet comprising polyaramid fibers.
Inventors
- 👤 Robert G. Kraus
- 👤 James R. Quick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 06:44
CPC Classifications
D; D04; D04H; D04H1/00; D04H1/40; D04H1/42; D04H1/4382; D04H1/43835; B; B32; B32B; B32B5/00; B32B5/22; B32B5/24; B32B5/26; B29; B29C; B29C70/00; B29C70/04; B29C70/28; B29C70/40; B29C70/50; B29C70/504; B29C70/88; B29C70/882; B32B27/00; B32B27/12; B32B5/02; B32B5/022; B32B7/00; B32B7/04; B32B7/12; D04H1/413; D04H1/4209; D04H1/4218; D04H1/4234; D04H1/4242; D04H1/4326; D04H1/4334; D04H1/4342; D04H1/4374; D04H1/58; D04H1/64; H; H01; H01B; H01B1/00; H01B1/02; H01B1/04; H01B1/20; H01B1/24; H01B3/00; H01B3/18; H01B3/30; H01B3/303; H01B3/305; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/146; H05B3/20; H05B3/34; H05B3/36; B29K; B29K2995/00; B29K2995/0003; B29K2995/0005; B32B2262/00; B32B2262/02; B32B2262/0261; B32B2262/0269; B32B2262/10; B32B2262/101; B32B2262/103; B32B2262/106; B32B2307/00; B32B2307/20; B32B2307/202; B32B2307/206; B32B2307/30; B32B2307/306; B32B2307/3065; H05B2203/00; H05B2203/002; H05B2203/005; H05B2203/011; H05B2203/013; H05B2203/014; H05B2203/017; H05B2203/021; H05B2203/033
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
66 words
An electrically conductive non-woven web for a heating element comprising, in combination, conductive fibers having melting points no lower than about 400° F., electrical resistances no greater than about 25,000 ohm/cm, and lengths in the range of from about 1/8 inch to about two inches, and conductive particles, the conductive particles comprising from about 5% to about 50% of the final dry weight of the web.
Claim 2
Dependent Claim
66 words
An electrically conductive non-woven web for a heating element comprising, in combination, conductive fibers having melting points no lower than about 400° F., electrical resistances no greater than about 25,000 ohm/cm, and lengths in the range of from about 1/8 inch to about two inches, and conductive particles, the conductive particles comprising from about 5% to about 50% of the final dry weight of the web.
Claim 3
Dependent Claim
40 words
An electrically conductive non-woven web in accordance with claim 1 further comprising non-conductive fibers having high dielectric strengths, melting points no lower than about 250° F., and lengths in the range of from about 1/8 inch to about two inches.
Claim 4
Dependent Claim
24 words
An electrically conductive non-woven web in accordance with claim 2 wherein the average length of the conductive fibers is at least about 1/2 inch.
Claim 5
Dependent Claim
28 words
An electrically conductive non-woven web in accordance with claims 2 wherein the conductive fibers are selected from the group consisting of carbon fibers, metal fibers, and metal-coated fibers.
Claim 6
Dependent Claim
33 words
An electrically conductive non-woven web in accordance with claim 2 wherein the conductive fibers are selected from the group consisiting of carbon fibers, nickel-coated carbon fibers, silver-coated nylon fibers, and aluminized glass fibers.
Claim 7
Dependent Claim
28 words
An electrically conductive non-woven web in accordance with claim 2 wherein the conductive particles are selected from the group consisting of carbon black, metal powders, and metal flakes.
Claim 8
Dependent Claim
95 words
An electrically conductive non-woven web for a heating element comprising a non-woven sheet saturated with from about 10% to about 67% by the final dry weight of the web of a dispersion comprising conductive particles and a polymeric binder, the non-woven sheet comprising conductive fibers having melting points no lower than about 400° F., electrical resistances no greater than about 25,000 ohm/cm, and lengths in the range of from about 1/8 inch to about two inches, and the conductive particles comprising from about 5% to about 50% of the final dry weight of the web.
Claim 9
Dependent Claim
95 words
An electrically conductive non-woven web for a heating element comprising a non-woven sheet saturated with from about 10% to about 67% by the final dry weight of the web of a dispersion comprising conductive particles and a polymeric binder, the non-woven sheet comprising conductive fibers having melting points no lower than about 400° F., electrical resistances no greater than about 25,000 ohm/cm, and lengths in the range of from about 1/8 inch to about two inches, and the conductive particles comprising from about 5% to about 50% of the final dry weight of the web.
Claim 10
Dependent Claim
44 words
An electrically conductive non-woven web in accordance with claim 7 wherein the non-woven sheet further comprises non-conductive fibers having high dielectric strengths, melting points no lower than about 250° F., and lengths in the range of from about 1/8 inch to about two inches.
Claim 11
Dependent Claim
24 words
An electrically conductive non-woven web in accordance with claim 7 wherein the average length of the conductive fibers is at least about 1/2 inch.
Claim 12
Dependent Claim
17 words
An electrically conductive non-woven web in accordance with claim 9 wherein the dispersion is a water-based dispersion.
Claim 13
Dependent Claim
17 words
An electrically conductive non-woven web in accordance with claim 9 wherein the conductive particles are carbon black.
Claim 14
Dependent Claim
26 words
An electrically conductive non-woven web in accordance with claim 11 wherein the dry weight of the non-woven sheet is in the range of about 0.35-2 oz/sq/yd.
Claim 15
Dependent Claim
37 words
An electrically conductive non-woven web in accordance with claim 9 wherein the conductive fibers comprise a mixture of conductive fibers having a length greater than about 1/2" and conductive fibers having a length less than about 1/2".
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-12 | 1989-02-11 | 1989-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-12 | 1993-02-11 | 1993-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-12 | 1997-02-11 | 1997-08-13 | $7700.00 | Window Closed / Lapsed |