Abstract: A surgical drill guide for directing a guide tube toward a target. The guide tube has first and second sets of teeth extending along an exterior surface thereof. A through passage in an operating mechanism housing receives the guide tube. A first actuator or guide tube advancing mechanism uses a ratchet and pawl mechanism to advance the guide tube distally. A guide tube locking mechanism, that includes another ratchet and pawl mechanism prevents any unwanted proximal motion by providing a releasable lock against any unwanted proximal motion of the guide tube during use.

Abstract: A tissue retractor with an adjustable center claw. The retractor includes two pivoted retractor arms. An axially and angularly displaceable, spring biased clamping mechanism is positioned on the pivot axis. In a mounting position, a elongated clamping element aligns with a slot in the center claw. When the center claw is positioned and the clamp moves to its clamping position, the elongated clamping member clamps the center claw in position. The counterfacing surfaces of the center claw and the clamping member are toothed to provide a positive one-way ratchet clamp.