Integral position sensing apparatus for a hydraulic directional valve
US5497804A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 27, 1994 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Jun 27, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T137/8671
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An apparatus for determining the spool position of a directional valve is disclosed. A longitudinal valve housing has opposed ends and a plurality of fluid ports, and a spool moves reciprocatingly within the valve housing. A first spring disposed adjacent an end of the spool extends and retracts with the reciprocating movement of the spool. A first oscillator circuit is coupled to the first spring and is adapted to produce a first position signal in response to the inductance of the first spring. Finally, a logic device determines the incremental linear position of the spool relative to the housing in response to the frequency of the first position signal.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.