摘要 |
<p>A mechanical device forming part of the limiter assembly (1) associated with reversible electric actuators, typically for controlling pipeline valves, comprises a mechanism by which one or more limiters (3) can be held in the engaged position even after the trigger has been deactivated; the undesirable phenomenon of pumping (the effect of the actuator motor cutting in and out repeatedly) is prevented by a simple flexible ribbon (15) with teeth (16) positioned in such a way as to engage corresponding sprockets (17) that are capable of rotation on their respective shafts (12) in one direction only. <IMAGE></p> |