US4095207A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Thermal fuse
Assignee: GTE Sylvania Inc
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Filing: 1975-09-18
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Granted: 1978-06-13
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Expires: 1995-09-18
Abstract
Abstract An electric switch for thermal overload protection includes a meltable pellet containing a pool of mercury which establishes electrical contact between two lead-in wires. When the pellet is heated to its melting point, the mercury becomes unconfined and the circuit is opened.
Inventors
- 👤 Warren H. Hay
- 👤 Stephen F. Kimball
- 👤 Roy C. Martin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:31
CPC Classifications
H; H01; H01H; H01H69/00; H01H69/02; H01H37/00; H01H37/74; H01H37/76; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49107
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
149 words
A thermally responsive electric switch comprising an elongated cylindrical body having an integral intermediate section at one end thereof, said section having a small diameter axial hole therethrough; a cylindrical meltable pellet coaxially disposed within said elongated cylindrical body and bearing against said integral intermediate section, said pellet having a small diameter axial hole therethrough; a cylindrical plug coaxially disposed within, and closing off the other end of, said elongated cylindrical body and bearing against said pellet, said plug having a small diameter axial hole therethrough; a lead-in wire extending through the hole in said integral intermediate section and slightly into the hole in said pellet; another lead-in wire extending through the hole in said cylindrical plug and slightly into the hole in said pellet; and a pool of mercury filling the holein said pellt and in contact with both lead-in wires so as to establish electrical continuity therebetween.
Claim 2
Dependent Claim
149 words
A thermally responsive electric switch comprising an elongated cylindrical body having an integral intermediate section at one end thereof, said section having a small diameter axial hole therethrough; a cylindrical meltable pellet coaxially disposed within said elongated cylindrical body and bearing against said integral intermediate section, said pellet having a small diameter axial hole therethrough; a cylindrical plug coaxially disposed within, and closing off the other end of, said elongated cylindrical body and bearing against said pellet, said plug having a small diameter axial hole therethrough; a lead-in wire extending through the hole in said integral intermediate section and slightly into the hole in said pellet; another lead-in wire extending through the hole in said cylindrical plug and slightly into the hole in said pellet; and a pool of mercury filling the holein said pellt and in contact with both lead-in wires so as to establish electrical continuity therebetween.
Claim 3
Dependent Claim
28 words
The switch of claim 1 wherein the axial hole in said pellet is larger in diameter than the holes in said integral intermediate section and said cylindrical plug.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-06-12 | 1981-12-12 | 1982-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-06-12 | 1985-12-12 | 1986-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-06-12 | 1989-12-12 | 1990-06-13 | $7700.00 | Window Closed / Lapsed |