Patent US4210368A successfully refreshed from Google Patents.
US4210368A
Expired / Lapsed
US
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Tractor-trailer air-brake system
Assignee: BVT BERATUNGS VERWALTUNGS und
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Filing: 1978-08-01
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Granted: 1980-07-01
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Expires: 1998-08-01
Abstract
Abstract A tractor-trailer brake system has a tractor engine brake which can be turned on to brake the tractor, and which operates a switch that can open a valve in the air line to the trailer brakes to allow simultaneous energization of these trailer brakes. A timer is interposed between the switch and the solenoid valve in the air line to periodically close this valve and allow cooling off of the trailer disk brakes for several seconds while the tractor engine brake remains on. The ratio of on time to off time of the solenoid valve during operation of the tractor engine is at least 10:1.
Inventors
- 👤 Georg Sontheimer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 10:08
CPC Classifications
B; B60; B60T; B60T7/00; B60T7/12; B60T7/20; B60T13/00; B60T13/10; B60T13/66; B60T13/662
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
96 words
A tractor-trailer air-brake system comprising: a tractor engine brake; trailer air-powered disk wheel brakes; actuator means for energizing said tractor engine brake and thereby braking the tractor of a tractor-trailer having said system; means including an electrically operated valve operable between closed and open positions for pressurizing and energizing said trailer brakes on energization of said tractor brake to brake the trailer of said tractor; and timer means connected to said valve and to said actuator means for automatically periodically operating said valve to periodically de-energize said trailer brakes even while said tractor brake is energized.
Claim 2
Dependent Claim
96 words
A tractor-trailer air-brake system comprising: a tractor engine brake; trailer air-powered disk wheel brakes; actuator means for energizing said tractor engine brake and thereby braking the tractor of a tractor-trailer having said system; means including an electrically operated valve operable between closed and open positions for pressurizing and energizing said trailer brakes on energization of said tractor brake to brake the trailer of said tractor; and timer means connected to said valve and to said actuator means for automatically periodically operating said valve to periodically de-energize said trailer brakes even while said tractor brake is energized.
Claim 3
Dependent Claim
18 words
The system defined in claim 1 wherein said timer means includes a switch in series with said valve.
Claim 4
Dependent Claim
16 words
The system defined in claim 2 wherein said timer means is constituted as a sealed unit.
Claim 5
Dependent Claim
36 words
The system defined in claim 1 wherein said timer means operates said valve by maintaining same closed for substantially longer than it maintains said valve open, said trailer brakes being energized when said valve is open.
Claim 6
Dependent Claim
26 words
The system defined in claim 4 wherein the ratio between length of time closed and length of time open for said valve is at least 5:1.
Claim 7
Dependent Claim
20 words
The system defined in claim 5 wherein said ratio is generally 10:1 and said time open is generally 3 seconds.
Claim 8
Dependent Claim
30 words
The system defined in claim 1 wherein said timer means includes an oscillator and a switch in series with said valve whereby said valve is periodically closed by said oscillator.
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) | 1983-07-01 | 1983-12-31 | 1984-07-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-07-01 | 1987-12-31 | 1988-07-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-07-01 | 1991-12-31 | 1992-07-01 | $7700.00 | Window Closed / Lapsed |