Patent US3810304A successfully refreshed from Google Patents.
US3810304A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing thin, flexible heating elements
Assignee: Individual
•
Filing: 1969-10-03
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Granted: 1974-05-14
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Expires: 1989-10-03
Abstract
Abstract A method for producing thin flexible heating elements comprising a resistance foil inserted between plastic sheets. A pair of plastic sheets are fed between a pair of welding rollers with a web of resistance foil fed therebetween. A heating chamber encloses the welding rollers and a portion of the plastic sheets upstream of the welding rollers and air is circulated through this chamber to pre-heat the plastic sheets to approximately welding temperature before the sheets reach the welding rollers.
Inventors
- 👤 P Heibye
- 👤 R Heibye
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:48
CPC Classifications
F; F24; F24D; F24D13/00; F24D13/02; H; H05; H05B; H05B3/00; H05B3/20; H05B3/22; H05B3/26; H05B3/34; H05B3/36; H05B2203/00; H05B2203/002; H05B2203/003; H05B2203/014; H05B2203/017; Y; Y02; Y02B; Y02B30/00; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49083
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
137 words
A method for the production of thin, flexible heating elements of uniform gauge and breadth and comprising a resistance foil inserted between insulating plastic sheets, said method comprising the steps of feeding at least one resistance foil web into an enclosed heating chamber and between welding rolls also arranged completely in said chamber, providing a pair of plastic sheets each having at least one weldable layer into said enclosed chamber and then between said welding rolls for welding the resistance foil therebetween adjacent the weldable layer of each sheet, and heating the air within the chamber to approximately the welding temperature of said weldable layer to heat the welding rollers to approximately said welding temperature and also to heat the plastic sheets to approximately said welding temperature before they reach the welding rolls for the welding operation.
Claim 2
Independent Claim
137 words
A method for the production of thin, flexible heating elements of uniform gauge and breadth and comprising a resistance foil inserted between insulating plastic sheets, said method comprising the steps of feeding at least one resistance foil web into an enclosed heating chamber and between welding rolls also arranged completely in said chamber, providing a pair of plastic sheets each having at least one weldable layer into said enclosed chamber and then between said welding rolls for welding the resistance foil therebetween adjacent the weldable layer of each sheet, and heating the air within the chamber to approximately the welding temperature of said weldable layer to heat the welding rollers to approximately said welding temperature and also to heat the plastic sheets to approximately said welding temperature before they reach the welding rolls for the welding operation.
Claim 3
Dependent Claim
30 words
A method according to claim 1, characterized in that the plastic sheetings are heated in the heating chamber partly by being brought into contact with heating tubes or the like.
Claim 4
Dependent Claim
16 words
A method according to claim 1, wherein the chamber is heated by circulating hot air therethrough.
Claim 5
Dependent Claim
45 words
A method according to claim 1, wherein each sheet is formed of two layers including said weldable layer and a second layer on the side of the welding layer away from the other sheet, which other layer is not weldable at the said welding temperature.
Claim 6
Dependent Claim
18 words
A method according to claim 4, wherein the weldable layer is polyethylene and the other layer is polyester.
Claim 7
Dependent Claim
18 words
A method according to claim 5, including heating the chamber to a temperature in the order of 125*-155*C.
Claim 8
Dependent Claim
174 words
A method according to claim 1, including cutting rows of resistance foil from a foil web which is moved in relation to a number of mutually connected knives, which knives are arranged alternately in two rows across the web so as to form parallel, longitudinal slits arranged in alternately displaced relation in the longitudinal direction, all of said knives of both rows being connected to a common support which is movable about a common axis, said cutting including the steps of raising all of the knives simultaneously as a unit at the defining areas between two elements and thereafter lowering all of the knives again simultaneously after a predetermined interruption over a certain longitudinal distance, whereupon the foil web is provided with at least one supporting web and is cut transversely in such a manner that the cut touches or cuts every second slit for alternately one and the other heating element, positioned on each side of the cut, thus providing a meander shaped resistance element which leaves the cutting device with equal orientation.
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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) | 1977-05-13 | 1977-11-12 | 1978-05-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-13 | 1981-11-12 | 1982-05-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-13 | 1985-11-12 | 1986-05-14 | $7700.00 | Window Closed / Lapsed |