Patent US3928909A successfully refreshed from Google Patents.
US3928909A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for producing cartridge heaters
Assignee: Kawaidenkiseisakusho KK
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Filing: 1974-07-12
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Granted: 1975-12-30
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Expires: 1994-07-12
Abstract
Abstract A method for producing cartridge heaters in which a going and returning heating coil is inserted into a heat-resisting cover pipe with an elliptical cross-section so as to align the crosssections of the going and the returning portions of the heating coil along the longer axis of the elliptical cross-section of the cover pipe, powdered insulator is charged in the space within the cover pipe not occupied by said coil, the longer axis is reduced by compressing the cover pipe in the direction along the longer axis and the cross-section of the heating coil is deformed into an ellipse having its longer axis perpendicular to the direction of the compression.
Inventors
- 👤 Isamu Saku
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 12:51
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/42; H05B3/48; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083; Y10T29/49087; Y10T29/49089; Y10T29/49091
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
117 words
A method for producing cartridge heaters, which includes the steps of inserting a going and returning heating coil of a circular cross-section within a heat-resisting cover pipe with an elliptical cross-section, the cross-section of the going and returning portions of the heating coil being aligned along the longer axis of the elliptical cross-section of said cover pipe, charging powdered insulator in the region within the cover pipe not occupied by said heating coil and reducing said longer axis by compressing said cover pipe along said longer axis to deform the cross-section into a less eccentric ellipse and the crosssection of said heating coil into an elliptical one having its longer axis perpendicular to the direction of compression.
Claim 2
Independent Claim
117 words
A method for producing cartridge heaters, which includes the steps of inserting a going and returning heating coil of a circular cross-section within a heat-resisting cover pipe with an elliptical cross-section, the cross-section of the going and returning portions of the heating coil being aligned along the longer axis of the elliptical cross-section of said cover pipe, charging powdered insulator in the region within the cover pipe not occupied by said heating coil and reducing said longer axis by compressing said cover pipe along said longer axis to deform the cross-section into a less eccentric ellipse and the crosssection of said heating coil into an elliptical one having its longer axis perpendicular to the direction of compression.
Claim 3
Dependent Claim
51 words
A method for producing cartridge heaters according to claim 1 including the step of using a guiding jig having a cross-section suitable for being set within the cover pipe before compression and provided with a pair of parallel guiding paths for inserting said going and returning coil in said cover pipe.
Claim 4
Dependent Claim
27 words
A method for producing cartridge heaters according to claim 1 including the step of making the cross-section of said cover pipe circular by compressing said cover pipe.
References Cited (Backward Citations)
US2643317A
Cited
US2701410A
Cited
US2808492A
Cited
US2897467A
Cited
US3082511A
Cited
US3007235A
Cited
US3468023A
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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) | 1978-12-29 | 1979-06-30 | 1979-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-29 | 1983-06-30 | 1983-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-29 | 1987-06-30 | 1987-12-30 | $7700.00 | Window Closed / Lapsed |