Abstract: The invention is a mortise lock constructed for very simple conversion between multiple functions and left and right hand openings. The lock can include or omit retraction of the latch bolt from either side with a key, permanent locking of either side's retractor, removal of the stopworks, simultaneous retraction of the latchbolt and deadbolt, or locking the retractor when the deadbolt is thrown. All of these conversions are accomplished without opening the case cover by the insertion or removal of screws or parts through holes in the cover or case, with the screws either stopping a part from moving or providing a catch upon which a part acts. The changeover between right and left handed openings is accomplished through the backplate with removal of only the armor plate, by removing, reversing, and reinstalling the latchbolt.

Abstract: The apparatus is a torque limiting spindle for lock mechanisms. The interconnection between two parts of the spindle of the lock is a detent mechanism which disengages the two sections if excessive torque is applied. The apparatus has a first section of the spindle with grooves on a cylindrical surface and dowel pins held into the grooves by one or more springs. The second section of the spindle has fingers which engage the dowel pins to impart rotational motion to the first spindle section. If the torque applied between the two sections exceeds the limit determined by the springs, the dowel pins move out of the grooves to prevent damage to the mechanism.