Patient support systems with rotary actuators comprising rotation limiting devices

A patient support apparatus comprising:

• a patient support surface;
• a first member and a movable member, said movable member movable relative to said first member;
• and
• an actuator comprising:
• a gear assembly having an input element, an output element connected to said movable member, and a gear arrangement operable between said input element and said output element;
• a motor configured to apply drive torque to said input element to rotate said output element through said gear arrangement;
• and
• a rotation limiting device coupled to said gear assembly to permit movement of said movable member relative to said first member through application of said drive torque from said input element to said output element and prevent back drive torque applied to said output element from moving said movable member in at least one direction relative to said first member;
• wherein said rotation limiting device comprises a braking surface and a braking element, said braking element operably coupled to said input element and said output element for concurrent movement with said input element and said output element, with said braking element engageable with said braking surface to prevent back drive torque applied to said output element from moving said movable member relative to said first member.