US4356704A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Refrigerant compressor protective switch system
Assignee: Nissan Motor Co Ltd
•
Filing: 1980-10-02
•
Granted: 1982-11-02
•
Expires: 2000-10-02
Abstract
Abstract In a compressor protective switch system for the refrigerant compressor of the refrigeration system of an automotive air conditioner, a pressure sensitive switch adapted to be open in response to a refrigerant pressure lower than a relatively high predetermined value is paralleled by a positive temperature coefficient (PTC) resistance element or a series combination of a PTC resistance element and an atmospheric temperature sensitive switch adapted to be open in response to an atmospheric temperature lower than a predetermined value.
Inventors
- 👤 Masao Izumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 06:43
CPC Classifications
F; F25; F25B; F25B49/00; F25B49/02; F25B49/022; B; B60; B60H; B60H1/00; B60H1/32; B60H1/3204; B60H1/3225
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
145 words
A protective switch system for an electromagnetically operated clutch of a refrigerant compressor in a refrigeration system of an air conditioner for automotive use, wherein the improvement comprises a parallel combination of a pressure sensitive switch which is responsive to the pressure of the refrigerant to be circulated through said refrigeration system and which is operative to be open in response to a refrigerant pressure lower than a predetermined value on the high pressure side of the system, a positive temperature coefficient resistance element connected in parallel with said pressure sensitive switch, the parallel combination being connected in series with said clutch, and a temperature sensitive switch responsive to the temperature of atmospheric air and operative to be open in response to an atmospheric temperature lower than a predetermined value, said temperature sensitive switch being connected in series with said positive temperature coefficient resistance element.
Claim 2
Dependent Claim
145 words
A protective switch system for an electromagnetically operated clutch of a refrigerant compressor in a refrigeration system of an air conditioner for automotive use, wherein the improvement comprises a parallel combination of a pressure sensitive switch which is responsive to the pressure of the refrigerant to be circulated through said refrigeration system and which is operative to be open in response to a refrigerant pressure lower than a predetermined value on the high pressure side of the system, a positive temperature coefficient resistance element connected in parallel with said pressure sensitive switch, the parallel combination being connected in series with said clutch, and a temperature sensitive switch responsive to the temperature of atmospheric air and operative to be open in response to an atmospheric temperature lower than a predetermined value, said temperature sensitive switch being connected in series with said positive temperature coefficient resistance element.
Claim 3
Dependent Claim
22 words
A protective switch system as set forth in claim 1, wherein said resistance element consists of a positive temperature coefficient ceramic thermistor.
Claim 4
Dependent Claim
65 words
A protective switch system as set forth in claim 1, further comprising a refrigerant temperature sensitive switch which is responsive to the temperature of the refrigerant to be circulated through said refrigeration system and which is operative to be open in response to a refrigerant temperature higher than a predetermined value, the refrigerant temperature sensitive switch being connected in series with said pressure sensitive switch.
Claim 5
Dependent Claim
62 words
A protective switch system as set forth in claim 1, further comprising a relay switch having normally open contact elements electrically connected between said electromagnetic clutch and a power source and an exciting coil connected between said power source and said pressure sensitive switch for causing said contact elements to close when energized from said power source through said pressure sensitive switch.
Claim 6
Dependent Claim
65 words
A protective switch system as set forth in claim 4, further comprising a refrigerant temperature sensitive switch which is responsive to the temperature of the refrigerant to be circulated through said refrigeration system and which is operative to be open in response to a refrigerant temperature higher than a predetermined value, the refrigerant temperature sensitive switch being connected in series with said pressure sensitive switch.
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) | 1985-11-01 | 1986-05-03 | 1986-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-01 | 1990-05-03 | 1990-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-01 | 1994-05-03 | 1994-11-02 | $7700.00 | Window Closed / Lapsed |