US3683361A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the manufacture of flat heating conductors and flat heating conductors obtained by this process
Assignee: Hoechst AG
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Filing: 1971-02-18
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Granted: 1972-08-08
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Expires: 1991-02-18
Abstract
Abstract In the manufacture of a flat heating conductor, i.e., an electrical resistance heating element, at least two metallic conductors are embedded in a layer of a film-forming plastics dispersion which has been filled with carbon black, whereupon the plastics dispersion is dried.
Inventors
- 👤 Manfred Salzwedel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:39
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/12; H05B3/14; H05B3/146; F; F24; F24D; F24D13/00; F24D13/02; Y; Y02; Y02B; Y02B30/00; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
53 words
The process as defined in claim 1 wherein said dispersion preparing step includes the step of mixing said dispersion in a homogeneous mass including 150 parts by weight of a copolymer of said vinyl acetate and dibutyl maleate, having a 50 percent solids content, and 10 parts by weight of said carbon black.
Claim 2
Dependent Claim
35 words
The method as defined in claim 2 wherein said mixing step includes adding 10 parts by weight of fibers to said homogeneous mass, said fibers being selected from the group consisting of polyesters and polyamides.
Claim 3
Dependent Claim
18 words
The method as defineD in claim 3 wherein said carbon black is obtained by thermal splitting of acetylene.
Claim 4
Dependent Claim
102 words
The process for manufacturing electrical resistance heating elements comprising the steps of preparing a liquid plastic dispersion including vinyl acetate, dibutyl maleate, carbon black, obtained by thermal splitting of acetylene, and cut polyester fibers, placing a first layer of said dispersion in a hold having a predetermined configuration, placing at least two metallic conductors on the upper surface of said layer, in spaced relation to each other, thereafter embedding said conductors in said dispersion by placing a second layer of said dispersion in said mold over said conductors and said first layer and drying said dispersion layers with said conductors embedded therebetween.
Claim 5
Dependent Claim
37 words
An electrical resistance heating element comprising a sheet of plastic dispersion formed essentially of vinyl acetate and dibutyl maleate filled with carbon black, and at least two metallic conductors embedded in said sheet between opposed surfaces thereof.
Claim 6
Dependent Claim
21 words
An electrical resistance heating element as defined in claim 6 wherein said carbon black is obtained by thermal splitting of acetylene.
Claim 7
Dependent Claim
29 words
An electrical resistance heating element as defined in claim 7 including fiber cuttings mixed in said dispersion, said fibers being selected from the group consisting of polyesters and polyamides.
Claim 8
Dependent Claim
20 words
An electrical resistance heating element as defined in claim 8 wherein said metallic conductors are formed of fine-meshed screen cloth.
Claim 9
Dependent Claim
44 words
An electrical resistance heating element as defined in claim 9 wherein said dispersion includes 150 parts by weight of a copolymer of said vinyl acetate and dibutyl maleate, 10 parts by weight of said carbon black, and 10 parts by weight of said fibers.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |