US4242573A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Water immersible heater
Assignee: Littelfuse Inc
•
Filing: 1979-01-24
•
Granted: 1980-12-30
•
Expires: 1999-01-24
Abstract
Abstract A heater immersible in liquids such as water suitable for water beds and a method for producing the heater are disclosed. The heater includes two-spaced apart metallic electrodes interconnected by a conductive polymeric matrix. A water-impermable barrier completely surrounds the polymeric matrix. A jacket of plasticized polyvinyl chloride can be placed around the barrier. The barrier also prevents plasticizer from the polyvinyl chloride from penetrating and damaging the conductive polymeric matrix.
Inventors
- 👤 Neville S. Batliwalla
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:52
CPC Classifications
A; A47; A47C; A47C27/00; A47C27/08; A47C27/085; A47C21/00; A47C21/04; A47C21/048; H; H01; H01C; H01C7/00; H01C7/02
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
89 words
A flexible, electrically conductive, temperature self-limiting heater suitable for immersion in water comprising: (a) two spaced apart metallic electrodes; (b) an electrically conductive polymeric composition interconnecting the electrodes; (c) an electrically insulating prejacket around the polymeric composition; (d) a flexible, corrosion resistant, electrically non-conductive, water impermeable barrier around the insulating prejacket, the barrier comprising an inner sheet of polyester film, a flat strip of aluminum, and an outer sheet of polyester film; (e) an electrically conductive grounding braid around the barrier; and (f) an electrically insulating polymeric outer jacket.
Claim 2
Dependent Claim
89 words
A flexible, electrically conductive, temperature self-limiting heater suitable for immersion in water comprising: (a) two spaced apart metallic electrodes; (b) an electrically conductive polymeric composition interconnecting the electrodes; (c) an electrically insulating prejacket around the polymeric composition; (d) a flexible, corrosion resistant, electrically non-conductive, water impermeable barrier around the insulating prejacket, the barrier comprising an inner sheet of polyester film, a flat strip of aluminum, and an outer sheet of polyester film; (e) an electrically conductive grounding braid around the barrier; and (f) an electrically insulating polymeric outer jacket.
Claim 3
Dependent Claim
35 words
The heater of claim 1 in which the inner surface of the barrier has an adhesive layer upon it for bonding the inner surface of the barrier to the outer surface of the insulating prejacket.
Claim 4
Dependent Claim
25 words
The heater of claim 2 in which the barrier is placed around the insulating prejacket such that the barrier overlaps itself and bonds to itself.
Claim 5
Dependent Claim
30 words
The heater of claim 1 in which the aluminum strip has a thickness of about 1 mil and each sheet of polyester film has a thickness of about 1/2 mil.
Claim 6
Dependent Claim
23 words
The heater of claim 1 in which the braid comprises about 16 bobbins, each bobbin comprising about 7 strips of 34 gauge wire.
Claim 7
Dependent Claim
24 words
The heater of claim 5 in which the braid is longitudinally wrapped around the barrier at a braid angle of at least about 50°.
Claim 8
Dependent Claim
13 words
The heater of claim 1 in which the prejacket is made of polyurethane.
Claim 9
Dependent Claim
18 words
The heater of claim 1 or 7 in which the outer jacket is made of plasticized polyvinyl chloride.
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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) | 1983-12-30 | 1984-06-30 | 1984-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-30 | 1988-06-30 | 1988-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-30 | 1992-06-30 | 1992-12-30 | $7700.00 | Window Closed / Lapsed |