Sequence controlling mechanical actuator partic. for valves - in automatic regeneration process for water treatment plant

摘要

Operation sequence controlling, mechanical actuator in which an actuating link derives its motion from a timing gear which has arcs of teeth meshing with a constantly rotating drive gear, the timing gear arcs of teeth alternating with toothless arcs so that drive ceases as the timing gear presents a toothless arc to the drive gear. The drive gear provides a continuous rotation to a meshing control gear having projecting studs which can be adjustably positioned so that rotation of the control gear will cause a stud to hit one arm of a bell-crank lever which pivots to effect disengagement of a spring-loaded catch from locking with the timing gear which is thus freed to rotate as the second arm of the bell crank lever pushes against a stud in the face of the timing gear to bring the next arc of teeth into mesh with the driving gear. The mechanism is used to automatically control the sequence of process operations, esp. opening and closing valves in regenerating a water softening plant.