Hydraulic brake booster
US4387569A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 6, 1980 |
| Grant date | Jun 14, 1983 |
| Priority date | — |
| Expiry date | Nov 6, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/162
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydraulic brake booster which has an input valve control member acting through a controlled rate spring and through a lever pivoted on the booster housing in the power chamber to move a spool valve in a bore parallel to the power piston so that the input is strictly through the spring. The lever has no connection to the power piston. The control valve is hydraulically unbalanced to a release position and is also urged to the release position by a valve spring. This maintains a proportion between the input force due to the reaction spring, through which input force is applied, and booster pressure. Upon power runout or failure the input and reaction piston overtravels and contacts the output rod to move that rod without moving the power piston.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.