Brake booster
US6119577A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Nov 6, 1998 |
| Grant date | Sep 19, 2000 |
| Priority date | — |
| Expiry date | Nov 6, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/72
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A tandem brake booster includes a solenoid within a valve body, and the solenoid may be energized to move a first tubular member disposed on the valve body rearward. When an input shaft is driven forward in the inoperative condition of the brake booster, a vacuum valve is closed while an atmosphere valve is opened in the similar manner as occurs in the prior art, thus actuating the tandem brake booster 1. When an input or the force of depression applied to a brake pedal rises to a given value X during the operative condition of the brake booster, the solenoid is energized, whereupon the first tubular member is moved rearward relative to the valve body, and the valve element is also moved rearward. This opens the atmosphere valve which has been closed during the servo balance condition, allowing a further introduction of the atmosphere into variable pressure chambers B, D, enabling a rise in the output even though the input remains unchanged. In this manner, the invention provides a functioning which is equivalent to a brake booster which is arranged to provide a variable servo ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.