Failed booster back-up braking system
US5709438A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 19, 1996 |
| Grant date | Jan 20, 1998 |
| Priority date | — |
| Expiry date | Dec 19, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S303/04
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A back-up power assisted braking system substitutes an intermittently actuated secondary source of pressurized hydraulic fluid such as a traction control/anti-lock pump and motor (41) for the normal braking power assist upon the detection of a failure in the primary power assisted braking system. A failure may be detected in responsive to sensing simultaneous brake pedal (23) displacement and a lack of fluid flow for providing an abnormality signal. Also, a failure may be detected by sensing a predetermined difference between the commanded braking force (45) and the actual braking forces (38, 49). There is a pressure transducer (45) which provides an indication of brake pedal commanded braking force and a hydraulic circuit (43, 53 or 55, 51) interconnecting the secondary source outlet, the individual wheel brake actuators (14) and secondary source inlet. A normally open solenoid operated valve (31, 47) is interposed in the hydraulic circuit between the wheel brake actuators and the secondary source inlet, and a control arrangement is coupled to the pressure transducer to provide an output voltage for enabling the solenoid of the solenoid operated hydraulic valve having a magnitude …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.