US4902874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anti-frost system for a windshield of a motor vehicle
Assignee: Subaru Corp
•
Filing: 1988-10-20
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Granted: 1990-02-20
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Expires: 2008-10-20
Abstract
Abstract A system for preventing frost from accumulating on a window of a motor vehicle has a heating element provided on the window, a temperature switch, which is closed when the temperature of window is lower than 0° C., and a humidity switch, which is closed when the humidity of air outside of the window becomes slightly lower than 100% relative humidity. When both the switches are closed, an electric circuit is closed to connect a battery with the heating element, thereby preventing the formation of frost on the window.
Inventors
- 👤 Takeshi Tachimori
- 👤 Hirohisa Takada
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:21
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/84; B; B60; B60S; B60S1/00; B60S1/02; B60S1/023; B60S1/026; G; G05; G05D; G05D27/00; G05D27/02; H05B1/00; H05B1/02; H05B1/0227; H05B1/023; H05B1/0236; H05B2203/00; H05B2203/035
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
80 words
A system for preventing frost from accumulating on a window of a motor vehicle comprising; a heating element provided on the window; a manual switch; a temperature switch closing when the temperature of the window is lower than 0° C.; a humidity switch closing when the humidity of air outside of the window becomes slightly lower than 100% relative humidity; and an electric circuit connecting the heating element, manual switch, temperature switch and humidity switch to a battery in series.
Claim 2
Independent Claim
80 words
A system for preventing frost from accumulating on a window of a motor vehicle comprising; a heating element provided on the window; a manual switch; a temperature switch closing when the temperature of the window is lower than 0° C.; a humidity switch closing when the humidity of air outside of the window becomes slightly lower than 100% relative humidity; and an electric circuit connecting the heating element, manual switch, temperature switch and humidity switch to a battery in series.
Claim 3
Dependent Claim
34 words
The system according to claim 1 wherein the circuit is connected to the battery through a relay switch which is closed when an ignition switch of an engine of the motor vehicle is closed.
Claim 4
Dependent Claim
20 words
The system according to claim 1 wherein the heating element is made of transparent conductive material embedded in the window.
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) | 1993-02-19 | 1993-08-21 | 1994-02-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-02-19 | 1997-08-21 | 1998-02-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-02-19 | 2001-08-21 | 2002-02-20 | $7700.00 | Window Closed / Lapsed |