Tandem brake pressure control valve with pressure-failure-compensating parallel piston
US4798127A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 26, 1987 |
| Grant date | Jan 17, 1989 |
| Priority date | — |
| Expiry date | May 26, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/141
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
Hydraulic assistance device for brake actuation comprising a body (10) having a bore (12) in which first and second piston mechanisms (34, 56) are slidably mounted, the first piston mechanism (34) being displaceable under the effect of the actuation of a third piston (16) mounted slideably in the bore (12), and the second piston mechanism (56) being displaceable by way of a hydrostatic connection formed in a presure chamber (60) defined between the first and the second piston mechanism (34, 56), there being associated with each piston mechanism (34, 56) a respective valve mechanism (52, 78) in a respective hydraulic circuit between a fluid source under pressure (54, 84) and a respective brake circuit (62,88), and a third chamber (30) defined in the bore (12) between the first piston mechanism (34) and the third piston (16), characterized in that the third chamber (30) is partially delimited by a fourth piston (92) which is displaceable under the effect of the pressure in the third chamber (30) as it meets a first spring mechanism (102; 104, 144).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.