System for positioning a piston including a fail fixed valve for holding the piston in position during a power interruption and method of using same
US7296406B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 2006 |
| Grant date | Nov 20, 2007 |
| Priority date | — |
| Expiry date | Feb 28, 2026 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF15B2211/875
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A controlled piston (20, 62, 102) having a first end (24, 64, 104) mounted in a controlled piston sleeve (22) and a spool (16) movably mounted in a spool sleeve (18), a first fluid passage (40, 66, 108) from the spool (16) to the controlled piston first end (24, 64, 104), the position of the spool (16) affecting a position of the controlled piston (20, 62, 102), an FFV (42, 68, 110) in an FFV sleeve (44, 70, 112) in the first fluid passage (40, 66, 108) having a first end section (46, 74, 116), a second end section (48, 78, 120) and a central section (50, 82, 126) having a third diameter less than the diameters of the first and second sections, the FFV (42, 68, 110) being shiftable between a first position blocking the first fluid passage (40, 66, 108) and a second position allowing fluid flow past the central section (50, 82, 126) to the controlled piston (20, 62, 102), and a second fluid passage (56, 88, 134) from the spool (16) to the FFV first end section (46, 74, 116). Shifting the spool (16) to a failsafe position shifts the FFV (42, 68, 110) to the first position to fix the controlled piston (20, 62, 102) in place.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.