US4272673A
Expired / Lapsed
US
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Heating element
Assignee: Rhone Poulenc Industries SA
•
Filing: 1979-04-16
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Granted: 1981-06-09
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Expires: 1999-04-16
Abstract
Abstract A heating element is comprised of [A] a shaped, electrically insulating substrate, said substrate including a reinforced polyimide composite, [B] a continuous, electric resistor element in entwining relationship with, and at least partially inlain within said composite [A], said electric resistor element being coated with a thermostable electrically insulating coating, and [C] means for coupling said electric resistor element [B] with an electric power source. Techniques for the fabrication of such heating elements are also disclosed.
Inventors
- 👤 Daniel Semanaz
- 👤 Robert Cassat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 05:44
CPC Classifications
H; H01; H01B; H01B3/00; H01B3/18; H01B3/48; H01B3/30; H01B3/303; H01B3/306; H05; H05B; H05B3/00; H05B3/10; H05B3/16
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
73 words
A heating element which comprises: a generally flat and generally solid, electrically insulating substrate, said substrate comprising a reinforced polyimide resin composite; a continuous electric resistor wire element of a predetermined resistance wound around and at least partially inlain within said composite, said electric resistor wire element being integrally coated with a layer of a thermostable, electrically insulating coating; and means for coupling said electric resistor wire element with an electric power source.
Claim 2
Dependent Claim
73 words
A heating element which comprises: a generally flat and generally solid, electrically insulating substrate, said substrate comprising a reinforced polyimide resin composite; a continuous electric resistor wire element of a predetermined resistance wound around and at least partially inlain within said composite, said electric resistor wire element being integrally coated with a layer of a thermostable, electrically insulating coating; and means for coupling said electric resistor wire element with an electric power source.
Claim 3
Dependent Claim
19 words
The heating element as defined by claim 1, wherein said electric resistor wire element comprises a single, continuous wire.
Claim 4
Dependent Claim
48 words
The heating element as defined by claim 2, wherein said single, continuous wire of the electric resistor element defines a first set of wire segments provided on a first side of said substrate and a second set of wire segments provided on a second side of said substrate.
Claim 5
Dependent Claim
55 words
The heating element as defined by claim 3, wherein the wire segments of the first set are parallel to one another and the wire segments of the second set are parallel to one another with the wire segments of the first set being oriented crosswise with respect to the wire segments of the second set.
Claim 6
Dependent Claim
22 words
The heating element as defined by claim 1, wherein the polyimide resin composite comprises a strength reinforcing filler elongate in geometrical configuration.
Claim 7
Dependent Claim
22 words
The heating element as defined by claim 5, wherein the reinforcing filler is selected from the group consisting of fibers and flakes.
Claim 8
Dependent Claim
26 words
The heating element as defined by claim 6, wherein the thermostable, electrically insulating coating is of a material different from the polyimide resin comprising the substrate.
Claim 9
Dependent Claim
23 words
The heating element as defined by claim 7, wherein, the reinforcing filler comprises from about 40 to 90% of the total weight thereof.
Claim 10
Dependent Claim
23 words
The heating element as defined by claim 8, wherein the reinforcing filler comprises from about 55 to 80% of the total weight thereof.
Claim 11
Dependent Claim
42 words
The heating element as defined by claim 6, wherein the reinforcing filler is selected from the group consisting of mica flakes, asbestos fibers, glass fibers, ceramic fibers, nonwovens comprised of glass fibers, batts of glass fibers and nonwovens comprised of asbestos fibers.
Claim 12
Dependent Claim
30 words
The heating element as defined by claim 8, wherein the polyimide resin comprising the substrate is the reaction product of a bis-imide of an unsaturated dicarboxylic acid and a polyamine.
Claim 13
Dependent Claim
15 words
The heating element as defined by claim 11, wherein the polyimide resin is a pre-polymer.
Claim 14
Dependent Claim
17 words
The heating element as defined by claim 8, wherein the thermostable, electrically insulating coating is a polyamide-imide.
Claim 15
Dependent Claim
24 words
The heating element as defined by claim 8, wherein the electric resistor element is inlain to from about 80 to 100% of its diameter.
Claim 16
Dependent Claim
27 words
The heating element as defined by claim 14, wherein the plurality of wire segments are metal and have diameters ranging from between about 0.05 and 0.8 mm.
Claim 17
Dependent Claim
23 words
The heating element as defined by claim 15, wherein said wire segments are spaced at intervals of between about 1 and 10 mm.
Claim 18
Dependent Claim
21 words
The heating element as defined by claim 8, further comprising a second shaped, electrically insulating substrate contiguously adhered to the substrate.
Claim 19
Dependent Claim
27 words
The heating element as defined by claim 17, further comprising a metal layer face surface provided on an outer surface of said second shaped, electrically insulating substrate.
Claim 20
Dependent Claim
18 words
The heating element as defined by claim 18, wherein said metal layer comprises a heat reflecting face surface.
Claim 21
Dependent Claim
18 words
The heating element as defined by claim 18, wherein said metal layer comprises a heat distributing face surface.
Claim 22
Dependent Claim
13 words
The heating element as defined by claim 18, wherein the metal is aluminum.
Claim 23
Dependent Claim
40 words
The heating element as defined by claim 17, further comprising a third shaped, electrically insulating substrate, said third substrate also being contiguously adhered to the substrate, but on a side opposite to that which the said second substrate is adhered.
Claim 24
Dependent Claim
14 words
The heating element as defined by claim 8, in the shape of a receptacle.
Claim 25
Dependent Claim
21 words
The heating element as defined by claim 1, wherein said electric resistor wire element comprises at least two continuous parallel wires.
Claim 26
Dependent Claim
41 words
The heating element as defined by claim 24, wherein said wires define a first set of wire segments provided on a first side of said substrate and a second set of wire segments provided on a second side of said substrate.
Claim 27
Dependent Claim
55 words
The heating element as defined by claim 25, wherein the wire segments of the first set are parallel to one another and the wire segments of the second set are parallel to one another with the wire segments of the first set being oriented crosswise with respect to the wire segments of the second set.
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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) | 1984-06-08 | 1984-12-08 | 1985-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-08 | 1988-12-08 | 1989-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-08 | 1992-12-08 | 1993-06-09 | $7700.00 | Window Closed / Lapsed |