Gate valve with supplemental actuator
US4925154A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 18, 1989 |
| Grant date | May 15, 1990 |
| Priority date | — |
| Expiry date | Aug 18, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T74/18992
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
An improved gate valve having a body with a chamber and an inlet and an outlet extending therethrough into said chamber, a gate mounted for reciprocation in said chamber between open and closed positions, a pressure responsive actuator having a housing, a piston, a connection to the gate and an actuating stem extending from the housing, a supplemental actuator having a connection to the actuator housing, an operating stem connected to the actuating stem, the operating stem having a shoulder facing in the direction opposite to the direction of closing movement of the gate, roller levers pivotally mounted to be in engagement with the exterior of the operating stem and a spring urging the roller levers into tight engagement with the operating stem, the roller levers pivoting on engagement with the stem shoulder to exert a closing force on the stem. In a modified form of the invention, lever-roller assemblies are provided within the actuator to increase the closing force of the piston during the last portion of its stroke by changing the spring force provided by the actuator spring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.