Hydraulic parking brake control system
US4923254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 23, 1989 |
| Grant date | May 8, 1990 |
| Priority date | — |
| Expiry date | Feb 23, 2009 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T15/041
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydraulic control valve for controlling the parking brakes of a vehicle hydraulic braking system having mechanically applied parking brakes which are released by hydraulic pressure includes a housing having a mechanically actuated control valve and a diverter assembly. When the vehicle is parked, the parking brakes are vented to reservoir and fluid from the vehicle hydraulic pump is communicated directly from the inlet of the valve to the return or drain port of the valve. When the brakes are released, communication between the spring brakes and reservoir pressure is cut off, and fluid communicated into the inlet is diverted to the diverter assembly, which builds pressure to a predetermined level which is communicated to the vehicle parking brakes to release the latter. When the predetermined pressure level is attained, the diverter assembly automatically opens to permit fluid to bypass the diverter assembly back to the return or drain port.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.