US4350021A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device for preventing icing in an air conditioning unit for motor vehicles
Assignee: Volvo AB
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Filing: 1980-11-04
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Granted: 1982-09-21
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Expires: 2000-11-04
Abstract
Abstract A device for preventing icing in a thermostat-controlled evaporator in an air conditioning unit for motor vehicles including a first sensor for sensing the speed of the air through the evaporator and preferably also a second sensor for sensing the humidity of the air. A control unit sets the thermostat to a lowest permissible evaporator temperature which is dependent on the speed and humidity of the air.
Inventors
- 👤 Gustaf B. Lundstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:56
CPC Classifications
B; B60; B60H; B60H1/00; B60H1/32; B60H1/3204; B60H1/3205; B60H1/3207; B60H3/00; F; F25; F25D; F25D21/00; F25D21/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
77 words
A device for preventing icing in a thermostat-controlled evaporator in an air conditioning unit for motor vehicles, comprising a first sensor for sensing the speed of the air flowing through the evaporator, and control means which cooperates with the sensor and the thermostat to receive information on the air speed and to send a control order dependent thereon to the thermostat to reduce the lower limit for permissible evaporator temperatur with increasing air speed, and vice versa.
Claim 2
Independent Claim
77 words
A device for preventing icing in a thermostat-controlled evaporator in an air conditioning unit for motor vehicles, comprising a first sensor for sensing the speed of the air flowing through the evaporator, and control means which cooperates with the sensor and the thermostat to receive information on the air speed and to send a control order dependent thereon to the thermostat to reduce the lower limit for permissible evaporator temperatur with increasing air speed, and vice versa.
Claim 3
Dependent Claim
27 words
A device according to claim 1, in which the first sensor is a sensor body placed in the air stream for direct sensing of the air speed.
Claim 4
Dependent Claim
40 words
A device according to claim 1, in which the first sensor is a measuring device for indirect sensing of the air speed by measuring the consumption of electricity by an electric motor, which drives a fan producing the air stream.
Claim 5
Independent Claim
73 words
A device according to any one of claims 1 to 3, and a second sensor which is arranged to send to the control means information on the humidity of the air stream through the evaporator, the control means being disposed to send a control order dependent on both the air speed and humidity to the thermostat, so that the lower limit for permissible evaporator temperature is reduced with dropping humidity, and vice versa.
Claim 6
Independent Claim
17 words
A device according to any one of claims 1-3, in which the control means comprises a microcomputer.
Claim 7
Dependent Claim
14 words
A device according to claim 4 in which the control means comprises a microcomputer.
References Cited (Backward Citations)
US3465534A
Cited
US3464224A
Cited
FR1580833A
Cited
US3444698A
Cited
DE2205407A1
Cited
FR2125381B1
Cited
DE2438505A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-09-20 | 1986-03-22 | 1986-09-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-09-20 | 1990-03-22 | 1990-09-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-09-20 | 1994-03-22 | 1994-09-21 | $7700.00 | Window Closed / Lapsed |