Cam operated control system for valve positioner with adjustable shaft - has disc shaped plate with cam profile

摘要

A cam operated switching unit for a valve controller with an adjustable setting shaft. The cam is made from a ring shaped disc with the desired profile on the inner face. It is fixed to a base plate with a shaft at the axis of the space enclosed by the inner face of the cam disc. A microswitch is fixed to the shaft which when rotated will cause roller on the actuator lever to run along the track of the cam. The whole system is enclosed in a housing. The travel of the shaft is limited by the shape of the cam track which is calibrated enabling the starting and finish positions of the shaft to be set with accuracy.