Abstract: A torsion spring positioning device of a cylindrical lock includes a spindle outer casing through which a spindle extends and the spindle outer casing has two protrusions extending radially inward from an inner periphery thereof. The spindle has two slots defined in a periphery thereof and two stops extending radially outward from the periphery thereof so that two legs of the torsion spring respectively abut an end of the corresponding stop and an end of the corresponding protrusion. A washer is mounted to the spindle and has two notches defined in an outer periphery thereof so as to respectively receive the protrusions. A C-shaped clamping member is mounted to the spindle and has two stubs extending radially inward from an inner periphery thereof so as to be received in the slots.

Abstract: A cylinder shaft projects from a key cylinder along the center line of a sleeve, and first and second case shafts project from a case. A spring is coiled on the first case shaft, and the cylinder shaft is placed between the first and second case shafts. The cylinder shaft and the second case shaft are placed between both legs of the spring. When the key cylinder is rotated with respect to the sleeve by the proper key being inserted in the key cylinder, the spring imparts returning force to the cylinder shaft that is making an arcuate movement in a circular-arc groove formed in the case.

Abstract: An actuating structure is provided for a switch lock having a barrel with a plug which is key actuated for rotation therein. An actuator interconnects the rotatable plug with a rotatable shaft of the switch and cooperates with a rotatable stop plate connected to a return spring. Specifically, an actuator lug and a stop plate surface which engage upon rotation of the plug in one direction to turn the switch momentarily from the first position to a second position against the action of the spring. The actuator also rotates in the opposite direction independently of the stop plate to turn the switch from the first to a third position.

Abstract: A flush-mountable, key-controlled, handle-operated door lock is provided with an automatic self-locking linkage for permitting the handle to move once, but only once, out of a nested position after a key control has been operated to "cock" the linkage. Once the linkage has been cocked, the handle can be moved one time out of and returned to its nested position, whereafter the linkage operates to retain the handle in its nested position until the key control is again operated to cock the linkage. The automatic latching linkage includes a housing assembly, a pair of cams, and a pair of springs. A feature of the automatic latching linkage is that its several components can be assembled easily on an existing, in-service lock to provide the existing lock with a one-trip automatic locking capability. The latching linkage components are assembled by installing the components one at a time in an essentially stacked arrangement, one atop the other.