Patent US3887238A successfully refreshed from Google Patents.
US3887238A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tractor-trailer braking system with variable motor speed control device
Assignee: Motors Liquidation Co
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Filing: 1974-03-13
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Granted: 1975-06-03
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Expires: 1994-03-13
Abstract
Abstract A vehicle brake system, particularly adapted for tractor and trailer usage, in which the first brake subsystem, on the tractor, includes a master cylinder operating the tractor brakes in response to actuation of a hydraulic brake booster which receives power pressure from the power steering gear pump. The booster has a secondary power pressure source which is in electric motor driven pump actuated when the power steering gear pump does not supply fluid to the brake booster. This type of system is known in the prior art, being utilized on medium trucks manufactured by the assignee of this invention. The second brake subsystem includes a similar hydraulic brake booster and master cylinder arrangement with an electric motor driven pump which provides pressure to the second subsystem booster in capacity and duration which correspond to the capacity and duration of the brake actuation in the first brake subsystem. This booster is so arranged that it is operated when such pressure is supplied thereto and does not require an independent valve-control operation. The booster is also supplied with a normally open bypass valve which balances pressures throughout the booster to permit brake release, the bypass valve being closed when the electric motor driven pump is operating. A motor proportional control circuit is operated by pressure sensing device connected in the brake apply pressure circuit of the first brake subsystem. This sensing means sends signals to the motor proportional control circuit which correspond to the presence of brake apply pressure and the amount of brake apply pressure. The controls therefore cause the second brake subsystem to be operated in proportion to the operation of the first subsystem.
Inventors
- 👤 Ronald W Bennett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:07
CPC Classifications
B; B60; B60T; B60T17/00; B60T17/18; B60T17/22; B60T13/00; B60T13/10; B60T13/12; B60T13/16; B60T13/161; B60T13/168
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
140 words
A vehicle tractor and trailer brake system comprising: a tractor brake system including means generating pressure for system brake operation in accordance with the braking effort demand of the vehicle operator, a trailer brake system including a brake booster having as a power pressure source a pump and a variable speed electric motor driving said pump to generate the booster power pressure, pressure transducer means in said tractor brake system sensing the pressure of and the amount of said generated pressure, and an electric motor control circuit electrically connected to said pressure transducer means and said electric motor to control the operation of said pump in accordance with the sensing action of said transducer to generate booster power pressure in said tractor brake system brake booster which is directly proportional to the sensed pressure generated in said tractor brake system.
Claim 2
Dependent Claim
140 words
A vehicle tractor and trailer brake system comprising: a tractor brake system including means generating pressure for system brake operation in accordance with the braking effort demand of the vehicle operator, a trailer brake system including a brake booster having as a power pressure source a pump and a variable speed electric motor driving said pump to generate the booster power pressure, pressure transducer means in said tractor brake system sensing the pressure of and the amount of said generated pressure, and an electric motor control circuit electrically connected to said pressure transducer means and said electric motor to control the operation of said pump in accordance with the sensing action of said transducer to generate booster power pressure in said tractor brake system brake booster which is directly proportional to the sensed pressure generated in said tractor brake system.
Claim 3
Dependent Claim
140 words
A vehicle tractor and trailer brake system comprising: a tractor brake system including means generating pressure for system brake operation in accordance with the braking effort demand of the vehicle operator, a trailer brake system including a brake booster having as a power pressure source a pump and a variable speed electric motor driving said pump to generate the booster power pressure, pressure transducer means in said tractor brake system sensing the pressure of and the amount of said generated pressure, and an electric motor control circuit electrically connected to said pressure transducer means and said electric motor to control the operation of said pump in accordance with the sensing action of said transducer to generate booster power pressure in said tractor brake system brake booster which is directly proportional to the sensed pressure generated in said tractor brake system.
Claim 4
Dependent Claim
140 words
A vehicle tractor and trailer brake system comprising: a tractor brake system including means generating pressure for system brake operation in accordance with the braking effort demand of the vehicle operator, a trailer brake system including a brake booster having as a power pressure source a pump and a variable speed electric motor driving said pump to generate the booster power pressure, pressure transducer means in said tractor brake system sensing the pressure of and the amount of said generated pressure, and an electric motor control circuit electrically connected to said pressure transducer means and said electric motor to control the operation of said pump in accordance with the sensing action of said transducer to generate booster power pressure in said tractor brake system brake booster which is directly proportional to the sensed pressure generated in said tractor brake system.
Claim 5
Dependent Claim
210 words
A vehicle brake system comprising: a first brake subsystem and a second brake subsystem each having a hydraulic pressure powered brake booster, a master cylinder operated by the brake booster, brakes applied by hydraulic pressure generated in the master cylinder in response to operation of the brake booster, and conduit means connecting the brakes and the master cylinder; a primary hydraulic power pressure source for said first brake subsystem booster and normally operable to supply hydraulic fluid thereto under pressure; a secondary hydraulic power pressure source for said first brake subsystem booster including an electric motor, a pump driven thereby, and control means sensitive to loss of fluid supply from said primary source to actuate said electric motor to drive said pump; a hydraulic power pressure source for said second brake subsystem booster including a second electric motor and a second pump driven thereby which are substantially identical to said secondary hydraulic power pressure source for said fiRst brake subsystem booster; and variable motor speed control means for said second motor sensitive to actuation of said first brake subsystem to generate hydraulic power pressure actuating said second brake subsystem booster in braking capacity and duration in accordance with the actuation of said first brake subsystem in braking capacity and duration.
Claim 6
Dependent Claim
210 words
A vehicle brake system comprising: a first brake subsystem and a second brake subsystem each having a hydraulic pressure powered brake booster, a master cylinder operated by the brake booster, brakes applied by hydraulic pressure generated in the master cylinder in response to operation of the brake booster, and conduit means connecting the brakes and the master cylinder; a primary hydraulic power pressure source for said first brake subsystem booster and normally operable to supply hydraulic fluid thereto under pressure; a secondary hydraulic power pressure source for said first brake subsystem booster including an electric motor, a pump driven thereby, and control means sensitive to loss of fluid supply from said primary source to actuate said electric motor to drive said pump; a hydraulic power pressure source for said second brake subsystem booster including a second electric motor and a second pump driven thereby which are substantially identical to said secondary hydraulic power pressure source for said fiRst brake subsystem booster; and variable motor speed control means for said second motor sensitive to actuation of said first brake subsystem to generate hydraulic power pressure actuating said second brake subsystem booster in braking capacity and duration in accordance with the actuation of said first brake subsystem in braking capacity and duration.
Claim 7
Dependent Claim
230 words
A vehicle brake system comprising: a first brake subsystem and a second brake subsystem each having a hydraulic pressure powered brake booster, a master cylinder operated by the brake booster, brakes applied by hydraulic pressure generated in the master cylinder in response to operation of the brake booster, and conduit means connecting the brakes and the master cylinder; a hydraulic power pressure source for said first brake subsystem booster and operable to supply hydraulic fluid thereto under pressure; a hydraulic power pressure source for said second brake subsystem booster including an electric motor and a pump driven thereby; variable motor speed control means for said motor sensitive to actuation of said first brake subsystem to generate hydraulic power pressure actuating said second brake subsystem booster in braking capacity and duration in accordance with the actuation of said first brake subsystem in braking capacity and duration; and means sensing brake apply pressure in said conduit means of said first brake subsystem and controlling the energization and speed of said second brake subsystem electric motor through said variable motor speed control means in accordance with the brake apply pressures generated by the first brake subsystem master cylinder and delivered through said first brake subsystem conduit means to said first brake subsystem brakes whereby the brake apply pressures in said second brake subsystem are directly proportional to those of said first brake subsystem.
Claim 8
Dependent Claim
230 words
A vehicle brake system comprising: a first brake subsystem and a second brake subsystem each having a hydraulic pressure powered brake booster, a master cylinder operated by the brake booster, brakes applied by hydraulic pressure generated in the master cylinder in response to operation of the brake booster, and conduit means connecting the brakes and the master cylinder; a hydraulic power pressure source for said first brake subsystem booster and operable to supply hydraulic fluid thereto under pressure; a hydraulic power pressure source for said second brake subsystem booster including an electric motor and a pump driven thereby; variable motor speed control means for said motor sensitive to actuation of said first brake subsystem to generate hydraulic power pressure actuating said second brake subsystem booster in braking capacity and duration in accordance with the actuation of said first brake subsystem in braking capacity and duration; and means sensing brake apply pressure in said conduit means of said first brake subsystem and controlling the energization and speed of said second brake subsystem electric motor through said variable motor speed control means in accordance with the brake apply pressures generated by the first brake subsystem master cylinder and delivered through said first brake subsystem conduit means to said first brake subsystem brakes whereby the brake apply pressures in said second brake subsystem are directly proportional to those of said first brake subsystem.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-06-02 | 1978-12-02 | 1979-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-02 | 1982-12-02 | 1983-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-02 | 1986-12-02 | 1987-06-03 | $7700.00 | Window Closed / Lapsed |