Patent US4673801A successfully refreshed from Google Patents.
US4673801A
Expired / Lapsed
US
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PTC heater assembly
Assignee: Tyco International Ltd
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Filing: 1985-06-28
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Granted: 1987-06-16
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Expires: 2005-06-28
Abstract
Abstract A PTC heater assembly comprises at least one PTC heater surrounded by an envelope of high thermal conductivity, thus greatly increasing the power output of the heater under operating conditions. In a preferred assembly a strip heater, comprising (i) an elongate strip of a conductive polymer PTC composition, (ii) electrodes embedded in said strip, and (iii) an insulating jacket, is sandwiched between a pair of metal, e.g. aluminum, sheets.
Inventors
- 👤 David F. Leary
- 👤 Alan Brigham
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:59
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/40; H05B3/54; H05B3/56
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
154 words
A heater assembly which comprises (a) a PTC heater which comprises at least one laminar PTC element of a conductive polymer composition, and at least two electrodes which are secured to a surface of the PTC element, which can be connected to a source to electrical power and which when so connected cause current to pass through said PTC element; (b) an electrically insulating jacket which surrounds said PTC element and said electrodes; and (c) an envelope which substantially surrounds and is in intimate thermal contact with said PTC heater which is electrically insulated from said PTC element and said electrodes by said insulating jacket, and which is composed of a material having a thermal conductivity of at least 0.1 Cal/cm. °C. sec; said heater assembly having an active power output at 50° F. which is at least 1.5 times the active power output at 50° F. of the PTC heater without the envelope.
Claim 2
Dependent Claim
154 words
A heater assembly which comprises (a) a PTC heater which comprises at least one laminar PTC element of a conductive polymer composition, and at least two electrodes which are secured to a surface of the PTC element, which can be connected to a source to electrical power and which when so connected cause current to pass through said PTC element; (b) an electrically insulating jacket which surrounds said PTC element and said electrodes; and (c) an envelope which substantially surrounds and is in intimate thermal contact with said PTC heater which is electrically insulated from said PTC element and said electrodes by said insulating jacket, and which is composed of a material having a thermal conductivity of at least 0.1 Cal/cm. °C. sec; said heater assembly having an active power output at 50° F. which is at least 1.5 times the active power output at 50° F. of the PTC heater without the envelope.
Claim 3
Dependent Claim
28 words
A heater assembly according to claim 1 wherein said PTC heater is sandwiched between a pair of elongate sheets which contact each other either side of the heater.
Claim 4
Dependent Claim
31 words
A heater assembly according to claim 2 wherein said elongate sheets are 1 to 50 mils thick and are composed of a material having a thermal conductivity of at least 0.3.
Claim 5
Dependent Claim
15 words
A heater assembly according to claim 2 wherein said sheets are composed of a metal.
Claim 6
Dependent Claim
12 words
A heater assembly according to claim 4 wherein said metal is aluminum.
Claim 7
Dependent Claim
16 words
A heater assembly according to claim 5 wherein said sheets are 3 to 8 mils thick.
Claim 8
Dependent Claim
27 words
A heater assembly according to claim 2 wherein the exposed surface area of said sheets is at least 1.5 times the surface area of said insulating jacket.
Claim 9
Dependent Claim
21 words
A heater assembly according to claim 1 wherein said PTC heater has a passive power rating of at least 70 watts/foot.
Claim 10
Dependent Claim
21 words
A heater assembly according to claim 8 wherein said PTC heater has a passive power rating of 70 to 200 watts/foot.
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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) | 1990-06-15 | 1990-12-15 | 1991-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-15 | 1994-12-15 | 1995-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-15 | 1998-12-15 | 1999-06-16 | $7700.00 | Window Closed / Lapsed |