Proportioning control valve with spring biased control piston
US4758051A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 11, 1987 |
| Grant date | Jul 19, 1988 |
| Priority date | — |
| Expiry date | Sep 11, 2007 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T11/34
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A proportioning control valve for a fluid pressure braking system for a tractor-trailer combination vehicle permits unproportioned communication of control pressure when the tractor is pulling a trailer but proportions communication of control pressure when the tractor is operated without a trailer to establish a proportionally lower pressure level at the outlet of the valve. When the pressure level at the control port exceeds a predetermined level established by a spring, the control valve proportions at a rate which increases the pressure level at the outlet at a rate greater than the rate of increase of control pressure until the unproportioned pressure level is attained.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.