Patent US3739147A successfully refreshed from Google Patents.
US3739147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Extruded contact electric heater strip
Assignee: EHD Inc
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Filing: 1972-03-23
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Granted: 1973-06-12
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Expires: 1992-03-23
Abstract
Abstract A thermally conductive casing and a method for forming the same for a contact heater resistance element in the form of an open extrusion of thermally conductive, soft metal which, in open form, will receive an elongate resistance element and which is then closed to confine the element and shaped into a configuration which draws the contacting edges of the extrusion into tight engagement to seal in the heating element.
Inventors
- 👤 W Mayhew
- 👤 W Disbrow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 05:30
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/54; H05B3/58
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
158 words
A contact electric heater strip comprising an electrically insulated, elongate resistance heating element and an elongate casing tightly enclosing said heating element, said casing comprising an integral, elongate, extrusion formed of a highly thermally conductive, formable metal, said extrusion having in cross-section a base formed with a flat contact surface on an outside and a semi-circular, cylindrical recess on an opposed surface on an inside, said base having side walls extending upwardly from the base to approximately a diameter of said cylindrical recess which is parallel to said base, and an integral, semi-circular extension on one of said walls arching over said recess with a free edge to contact a top edge of said other side to provide a closed, elongate, circular recess for containing a heating element, said closed extrusion being adapted to be bent around an axis spaced from said base away from said recess wherein said free edge is drawn tight against said other side.
Claim 2
Dependent Claim
158 words
A contact electric heater strip comprising an electrically insulated, elongate resistance heating element and an elongate casing tightly enclosing said heating element, said casing comprising an integral, elongate, extrusion formed of a highly thermally conductive, formable metal, said extrusion having in cross-section a base formed with a flat contact surface on an outside and a semi-circular, cylindrical recess on an opposed surface on an inside, said base having side walls extending upwardly from the base to approximately a diameter of said cylindrical recess which is parallel to said base, and an integral, semi-circular extension on one of said walls arching over said recess with a free edge to contact a top edge of said other side to provide a closed, elongate, circular recess for containing a heating element, said closed extrusion being adapted to be bent around an axis spaced from said base away from said recess wherein said free edge is drawn tight against said other side.
Claim 3
Dependent Claim
18 words
The contact electric heater strip as defined in claim 1, wherein the formable metal is of annealed aluminum.
Claim 4
Dependent Claim
20 words
The contact electric heater strip as defined in claim 1, wherein the formable metal is of dead soft metal material.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |