| 摘要 |
A remote throttling valve is disclosed which includes an internal valve seat and a valve operator arranged for longitudinal movement toward and away from the valve seat to open and close the valve. A threaded worm shaft carries the valve operator and is threadedly engaged in the valve body to longitudinally move the valve operator in response to rotation of the worm shaft. A ratchet gear exteriorly connects to the threaded worm shaft and is provided with a plurality of radially outwardly projecting ratchet teeth. A reversible motor including an eccentric drive functions first and second pawl fingers of a non-planar pawl into successive engagements with the ratchet gear teeth. Clockwise rotation of the motor causes intermittent rotation of the ratchet gear in a first direction and counter-clockwise rotation of the motor will cause intermittent rotation of the ratchet gear in the opposite direction. The ratchet teeth define forward and rearward clearance spaces about the ratchet gear whereby automatic longitudinal forward and rearward movement limits are provided when the pawl fingers respectively enter the forward and rearward clearance spaces.
|
