Hydraulic ratio changing booster with self-venting chamber
US4241642A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 22, 1979 |
| Grant date | Dec 30, 1980 |
| Priority date | — |
| Expiry date | Feb 22, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/144
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A hydraulic power booster system in which a hydraulic power brake booster has a hydraulic ratio changing mechanism. The ratio is established by trapping hydraulic fluid in a chamber with an input piston having a larger effective area than an output piston forming movable chamber walls. A ratio piston or sleeve exposed to booster power pressure and the trapped pressure is moved upon power runout, causing the booster ratio to change as the ratio of these pressures change, providing a smooth transition from a high ratio toward a 1:1 ratio as the booster shifts to manual operation from hydraulic power operation. A valve which operates to trap pressure in the chamber upon booster actuation also provides a vent path from the chamber when the booster is fully released so that any air in the chamber may be bled out.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.