Patent US3707634A successfully refreshed from Google Patents.
US3707634A
Expired / Lapsed
US
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Apparatus for extending contact life of relays utilized for a.c. load switching
Assignee: Unisys Corp
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Filing: 1971-03-31
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Granted: 1972-12-26
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Expires: 1991-03-31
Abstract
Abstract Apparatus for use with a relay utilized to switch alternating current loads to extend the contact life thereof. Circuits are included to cause alternate energization of the relay to occur in time coincidence with points on the alternating current waveform that are 180* apart, respectively. Thus, the alternate operations of the relay occur at alternate polarities of the a.c. waveform switched. Hence, contact material transferred from one contact to the other during one relay operation is re-transferred from the other contact to the one on the next following relay operation.
Inventors
- 👤 David Arlen
- 👤 Louis A Guido
- 👤 Lawrence P Quinn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 06:22
CPC Classifications
H; H01; H01H; H01H9/00; H01H9/54; H01H9/56
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
108 words
Apparatus for extending the life of the contacts of a relay adapted to be responsive to an energizing signal for switching an alternating current signal comprising first means (21, 24, 26, 30, 16) for applying said energizing signal to said relay at a predetermined phase angle of said alternating current signal, second means (21, 24, 25, 27, 30, 16) for applying said energizing signal to said relay at a phase angle of said alternating current signal approximately 180* phase displaced from said predetermined phase angle, and controlling means (32, 33) for alternately actuating said first and second means for a predetermined number of energizations of said relay respectively.
Claim 2
Dependent Claim
108 words
Apparatus for extending the life of the contacts of a relay adapted to be responsive to an energizing signal for switching an alternating current signal comprising first means (21, 24, 26, 30, 16) for applying said energizing signal to said relay at a predetermined phase angle of said alternating current signal, second means (21, 24, 25, 27, 30, 16) for applying said energizing signal to said relay at a phase angle of said alternating current signal approximately 180* phase displaced from said predetermined phase angle, and controlling means (32, 33) for alternately actuating said first and second means for a predetermined number of energizations of said relay respectively.
Claim 3
Dependent Claim
39 words
The apparatus of claim 1 in which said controlling means comprises bistable means (33) responsive to said energizations of said relay for alternately providing first and second control signals in response to said predetermined number of said energizations, respectively.
Claim 4
Dependent Claim
99 words
The apparatus of claim 2 in which said first means includes rectifying means (21) responsive to said alternating current signal for providing the half-cycles thereof of one polarity, means (24) responsive to said half-cycles for providing a first logic signal in accordance therewith, first gating means (26, 30) coupled to receive said first logic signal and said first control signal for transmitting said first logic signal in response to said first control signal, and relay energizing means (16) for applying said energizing signal to said relay at said predetermined phase angle in response to said transmitted first logic signal.
Claim 5
Dependent Claim
100 words
The apparatus of claim 3 in which said second means includes inverter means (25) responsive to said first logic signal for providing a second logic signal in accordance with the half-cycles of said alternating current signal of the polarity opposite said one pOlarity, and second gating means (27, 30) coupled to receive said second logic signal and said second control signal for transmitting said second logic signal to said relay energizing means in response to said second control signal thereby applying said energizing signal to said relay at said phase angle approximately 180* phase displaced from said predetermined phase angle.
Claim 6
Dependent Claim
52 words
The apparatus of claim 1 in which said controlling means comprises counting means (32) responsive to said energizations of said relay for providing signals representative of said predetermined numbers thereof, and bistable means (33) responsive to said counting means signals for alternately providing first and second control signals in response thereto, respectively.
Claim 7
Dependent Claim
38 words
The apparatus of claim 1 in which said controlling means comprises bistable means (33) responsive to said energizations of said relay for alternately providing first and second control signals in response to alternate energizations of said relay, respectively.
References Cited (Backward Citations)
US2162237A
Cited
US2157640A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-12-26 | 1976-06-26 | 1976-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-12-26 | 1980-06-26 | 1980-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-12-26 | 1984-06-26 | 1984-12-26 | $7700.00 | Window Closed / Lapsed |