Valve actuator
US5497672A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 27, 1993 |
| Grant date | Mar 12, 1996 |
| Priority date | — |
| Expiry date | Dec 27, 2013 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/18624
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A valve actuator comprises a stem extending through the actuator body for coupling to a valve such that axial movement of the stem opens and closes the valve. An outer shaft is arranged coaxially around, and in threaded engagement with the stem and is coupled to an electric motor for conveying rotational drive to the shaft and thus axial movement of the shaft relative to the stem against a spring bias. The shaft is releasably retained in a predetermined position by a solenoid-actuated latching mechanism with the spring in a compressed state, such that further rotation of the shaft causes axial movement of the stem relative to the shaft to actuate the valve. Deactuation of the mechanism releases the shaft to allow axial movement of both the shaft and the stem, under action of the spring in order to close the valve. The latching mechanism includes a plurality of retaining members which engage with an angled face of a wedge member, the angle of the wedge face with respect to the longitudinal axis of the stem being close to the angle of friction of the material of which the wedge member and retaining members are made.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.