Patent US4717814A successfully refreshed from Google Patents.
US4717814A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Slotted autoregulating heater
Assignee: Delaware Capital Formation Inc
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Filing: 1984-03-06
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Granted: 1988-01-05
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Expires: 2004-03-06
Abstract
Abstract Designation of specific heating zones and increase in minimum resistance relative to prior heaters of the type to which the present invention pertains is achieved, together with flexibility or bendability, if desired, by slotting the outer conductor of the heater. Additional flexibility is also achieved by confining the high mu material only to those regions of the device where heating is desired, the unslotted regions.
Inventors
- 👤 John F. Krumme
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:40
CPC Classifications
H; H05; H05B; H05B6/00; H05B6/02; H05B6/10; B; B23; B23K; B23K3/00; B23K3/04; B23K3/047; B23K3/0475; B23K9/00; B23K9/235; H05B3/00; H05B3/10; H05B3/12
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
93 words
A Curie temperature autoregulating heater comprising an outer conductor having a plurality of surfaces and at least one slot in a specified region of at least one of said surfaces, which slot is less in length than said surfaces and is positioned to interrupt current flow through at least a length of said outer conductor, ferromagnetic material disposed adjacent and in electrical and thermal contact with a surface of said outer conductor other than said region in said one of said surfaces, a return conduductor electrically connected in series with said ferromagnetic material.
Claim 2
Dependent Claim
93 words
A Curie temperature autoregulating heater comprising an outer conductor having a plurality of surfaces and at least one slot in a specified region of at least one of said surfaces, which slot is less in length than said surfaces and is positioned to interrupt current flow through at least a length of said outer conductor, ferromagnetic material disposed adjacent and in electrical and thermal contact with a surface of said outer conductor other than said region in said one of said surfaces, a return conduductor electrically connected in series with said ferromagnetic material.
Claim 3
Dependent Claim
29 words
A Curie temperature autoregulating heater as defined in claim 1 wherein said outer conductor is a hollow elongated structure, said ferromagnetic material being located interiorly of said hollow structure.
Claim 4
Dependent Claim
29 words
A Curie temperature autoregulating heater as defined in claim 1 or claim 2 wherein said one surface of said outer conductor has a plurality of spaced, generally transverse slots.
Claim 5
Dependent Claim
28 words
A Curie temperature autoregulating heater as defined in claim 3 wherein said plurality of slots are arranged along a majority of the elongated length of said hollow structure.
Claim 6
Dependent Claim
50 words
A Curie temperature autoregulating heater as defined in claim 4 wherein said elongated hollow structure is rectangular in cross-section and some of said slots extend across at least three of the sides of said hollow structure, and said ferromagnetic material is disposed adjacent the fourth side of said hollow structure.
Claim 7
Dependent Claim
30 words
A Curie temperature autoregulating heater as defined in claim 1 wherein said ferromagnetic material comprises a plurality of distinct lengths of ferromagnetic materials various of which have different Curie temperatures.
Claim 8
Dependent Claim
30 words
A Curie temperature autoregulating heater as defined in claim 2 wherein said ferromagnetic material comprises a plurality of distinct lengths of ferromagnetic materials various of which have different Curie temperatures.
Claim 9
Dependent Claim
31 words
A Curie temperature autoregulating heater as defined in claim 2 wherein said one surface has a plurality of slots having different widths transverse to the elongated dimension of said hollow structure.
Claim 10
Dependent Claim
50 words
A Curie temperature autoregulating heater as defined in claim 1 or claim 2 further comprising means for defining zones of different rates of heating of said heater, said means including slots in the surfaces of said hollow structure to define specific current densities in different regions of said ferromagnetic material.
Claim 11
Dependent Claim
34 words
A Curie temperature autoregulating heater as defined in claim 9 further comprising means controlling the electrical resistance of said heater, said means including slots formed in various of said surfaces of said hollow structure.
Claim 12
Dependent Claim
37 words
A Curie temperature autoregulating heater as defined in claim 1 or claim 2 further comprising means controlling the electrical resistance of said heater, said means including slots formed in various of said surfaces of said hollow structure.
Claim 13
Dependent Claim
32 words
A Curie temperature autoregulating heater as defined in claim 1 wherein said ferromagnetic material is at least five skin depths thick above Curie temperature at the operating frequency of current applied thereto.
Claim 14
Dependent Claim
20 words
A Curie temperature autoregulating heater as defined in claim 1 wherein said ferromagnetic material is less than two skin depths.
Claim 15
Dependent Claim
26 words
A Curie temperature autoregulating heater as defined in claim 13 further comprising a layer of conductive material lying between said ferromagnetic material and said outer conductor.
Claim 16
Dependent Claim
20 words
A Curie temperature autoregulating heater as defined in claim 4 wherein said slots are equally spaced along said elongated lengths.
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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) | 1991-01-04 | 1991-07-06 | 1992-01-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-01-04 | 1995-07-06 | 1996-01-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-01-04 | 1999-07-06 | 2000-01-05 | $7700.00 | Window Closed / Lapsed |