US3885129A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Positive temperature coefficient resistor heater
Assignee: Sprague Electric Co
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Filing: 1974-02-28
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Granted: 1975-05-20
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Expires: 1994-02-28
Abstract
Abstract A temperature regulating heating element comprises a PTCR body having a surface with a pair of adjacent electrodes oppositely connected to a voltage source by two lead wires, respectively. Thus in the PTCR body the electrical current and the source of heat is concentrated near the electroded surface. An electrically insulating layer may cover the electroded surface of the body to prevent shorting of the electrodes by a conducting object that is to be heated by thermal connection to the electroded surface.
Inventors
- 👤 John H Fabricius
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:46
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/02; H05B3/06; H05B3/10; H05B3/12; H05B3/14; H05B3/141; H05B3/68; H05B3/74; H05B3/748; H05B2203/00; H05B2203/02; H05B2213/00; H05B2213/07
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
111 words
A PTCR heater comprising a disc of PTCR material, said disc having two opposed flat surfaces and a perimeter face, a first pair of arcuate interdigitated metal film electrodes bonded to one of said surfaces, said electrodes each having a finger-like shape, the separation between adjacent portions of said electrodes being substantially constant, an electrical connective means for connecting the alternative of said electrodes to one lead and the remained of said electrodes to another lead, said leads being capable of connection to an electrical energy source such that said adjacent electrodes are oppositively polarized and the heating electric currents in said disc flow predominantly near said one of said surfaces.
Claim 2
Dependent Claim
111 words
A PTCR heater comprising a disc of PTCR material, said disc having two opposed flat surfaces and a perimeter face, a first pair of arcuate interdigitated metal film electrodes bonded to one of said surfaces, said electrodes each having a finger-like shape, the separation between adjacent portions of said electrodes being substantially constant, an electrical connective means for connecting the alternative of said electrodes to one lead and the remained of said electrodes to another lead, said leads being capable of connection to an electrical energy source such that said adjacent electrodes are oppositively polarized and the heating electric currents in said disc flow predominantly near said one of said surfaces.
Claim 3
Dependent Claim
32 words
The PTCR heater of claim 1 wherein said means include metal films on said one surface contacting said electrodes, said films extending over said perimeter face onto the other of said surfaces.
Claim 4
Dependent Claim
50 words
The PTCR heater of claim 1 wherein a second pair of arcuate interdigitated electrodes is bonded to the other of said surfaces, said second pair of electrodes having a pattern similar to the pattern of said first pair of electrodes, said disc having a thickness substantially equal to said separation.
Claim 5
Dependent Claim
54 words
The PTCR heater of claim 3 wherein said means include connections such that an electrode of each of said pairs of electrodes is at one polarity and the other electrode of each of said pairs of electrodes is at the opposite polarity, whereupon heating currents in said disc also flow near said perimeter face.
Claim 6
Dependent Claim
25 words
The PTCR heater of claim 1 additionally comprising an electrically insulating layer disposed over said electrode pattern and over the intervening areas of said surface.
Claim 7
Dependent Claim
29 words
The PTCR heater of claim 5 wherein said layer has been deposited over said pattern and said intervening areas of said surface in liquid form, cured and bonded thereto.
Claim 8
Dependent Claim
12 words
PTCR heater of claim 5 wherein said insulating layer consists of glass.
Claim 9
Dependent Claim
13 words
The PTCR heater of claim 5 wherein said insulating layer consists of ceramic.
Claim 10
Dependent Claim
16 words
The PTCR heater Of claim 5 wherein said insulating layer consists of a glass ceramic composite.
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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) | 1978-05-19 | 1978-11-18 | 1979-05-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-19 | 1982-11-18 | 1983-05-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-19 | 1986-11-18 | 1987-05-20 | $7700.00 | Window Closed / Lapsed |