Two-speed stepper actuator

摘要

A two-speed stepper actuator unit for use in paper machine headbox slice lip control has a spindle 16 driven by a power nut 24. A lever clamp 32 has legs 34 and 36 selectively clamped together around nut 24 by means of a cam action locking plate 40 driven by solenoid 48. The longer leg 36 of clamp 32 has a cam follower which rotationally drives nut 24 through the lever 36 in response to the shape of a cam plate 50 which translates in the housing 12 on antifriction rollers 66 when drive solenoid 54 is actuated. The cam surface 60 guides the lever 36 in either of two speed modes depending on whether spring biased roller follower 52 is on cams surface portion 62 or 64.