Negative pressure boosting device
US6782794B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 2002 |
| Grant date | Aug 31, 2004 |
| Priority date | — |
| Expiry date | Nov 12, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB60T13/52
- WIPO fieldTransport
- WIPO sectorMechanical engineering
Abstract
In a negative pressure boosting device, a movable valve seat is air-tightly and slidably disposed in a concavity of a valve body. The movable valve seat and a valve element compose a vacuum valve. A servo ratio changing device includes a control spring compressed and disposed between the movable valve seat and the valve body. The servo ratio changing device is provided on a valve mechanism (the vacuum valve). During operation, the valve element comes in contact with the movable valve seat. The movable valve seat does not move in a low-input range so that the servo ratio is a relatively large ratio for the normal operation. In a high-input range, the control spring starts to be compressed to move the movable valve seat, thereby changing the servo ratio to a small ratio.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.