Robotic arm rotation controller

摘要

An apparatus provides theta -rotational motion about a Z-axis. The apparatus is improved as follows. A stop structure is carried by the apparatus and rotates with it. The stop structure has a detent engagement structure. A detent structure comprises a rotatable member located adjacent to the stop structure. The rotatable member is mounted for free rotation about an axis parallel to the Z-axis. The rotatable member defines a plurality of detentes which are adapted for sequential engagement with the detent engaging structure as the stop structure rotates about the Z-axis. A biasing structure serves for biasing the stop member to deter it from rotating. The biasing structure is overcome by action of the detent engaging structure with any one of the detentes and otherwise prevents rotation of the stop member. A stationary detent is located adjacent the stop member. The stationary detent engages with and halts rotation of the stop member beyond a selected rotational position. It acts through the stop member to stop rotation of the apparatus about the Z-axis.