Power-assisted braking device with a variable assistance ratio
US5921084A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 28, 1997 |
| Grant date | Jul 13, 1999 |
| Priority date | — |
| Expiry date | May 28, 2017 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/565
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
A boosted braking device for a motor vehicle having a master cylinder (200) and a pneumatic booster (100) operated by applying an input force to an operating rod (26). The booster (100) has a rigid casing (10) which is divided by a partition (16) into at least first (12) and second (14) leaktight chambers. The partition (16) is acted upon via a difference in pressure between the first (12) and second (14) chambers on the opening of a three-way valve (24) to allow pressurized fluid to be communicated to the second chamber (14). A main hydraulic piston (30) which is located in the master cylinder (200) has a hollow cylinder (32) which is in communication with an interior volume (V) of the master cylinder (200). A secondary hydraulic piston (34) slides in a leaktight fashion inside of the hollow cylinder (32). The secondary hydraulic piston (34) includes a two-way valve (56) which is normally open but interrupts communication between the interior volume (V) of the master cylinder (200) and an interior volume (35) in the hollow cylinder (32) when a variation in an input force is greater than a predetermined value. The secondary hydraulic piston (14) is composite and includes a first pa…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.