Motorized lock actuator for cylindrical lockset

In a cylindrical lock of the type including a chassis having a hub and means for mounting the hub in a fixed position on a door, a handle sleeve mounted for rotation relative to the hub, the handle sleeve having means for supporting a door handle and latch-retracting means for retracting a movable latch coupled to the chassis, and means for locking the handle sleeve against rotation relative to the hub, the locking means being movable along the axis of rotation of the handle sleeve between a sleeve-locking position and a sleeve-unlocking position, the improvement comprising

• means for moving the locking means between its sleeve-locking and unlocking positions, the moving means including a plunger having an axis, a locking-assist spring coupled to the plunger and the locking means, and means for reciprocating the plunger along its axis in one of a locking direction against the locking-assist spring so that the locking-assist spring is moved toward the locking means to urge the locking means to its sleeve-locking position and an opposite unlocking direction away from the locking means so that the locking means is allowed to move to assume its sleeve-unlocking position, the reciprocating means including a spindle, means for rotating the spindle about an axis of rotation, and means for linking the spindle and the plunger to convert continuous rotation of the spindle about its axis of rotation into limited movement of the plunger along its axis in the locking direction and against the locking-assist spring to compress the locking-assist spring between the plunger and the locking means whenever an obstruction blocks movement of the locking means to its sleeve-unlocking position so that a predetermined amount of potential energy is stored in the locking-assist spring owing to its compressed state to enable the locking-assist spring to decompress and move the locking means to its sleeve-locking position upon removal of said obstruction without further axial movement of the plunger along its axis in the locking direction and against the locking-assist spring.

In a cylindrical lock of the type including a chassis having a hub and means for mounting the hub in a fixed position on a door, a handle sleeve mounted for rotation relative to the hub, the handle sleeve having means for supporting a door handle and latch-retracting means for retracting a movable latch coupled to the chassis, and means for locking the handle sleeve against rotation relative to the hub, the locking means being movable along the axis of rotation of the handle sleeve between a sleeve-locking position and a sleeve-unlocking position, the improvement comprising

• means for moving the locking means between its sleeve-locking and unlocking positions, the moving means including first spring means for yieldably biasing the locking means toward its sleeve-unlocking position, a rotatable spindle, a plunger mounted for reciprocating movement in the chassis, second spring means for yieldably biasing the locking means toward its sleeve-locking position, the second spring means being positioned between the plunger and the locking means to convert movement of the plunger toward the latch handle into movement of the locking means toward its sleeve-locking position, and means for coupling the spindle to the plunger to convert rotational movement of the spindle into axial movement of the plunger against the second spring means so that the locking means is moved by the second spring means against the first spring means from its sleeve-unlocking position to its sleeve-locking position.

A cylindrical lock comprising:

• a latch bolt, a chassis configured to mount on a door,
• means for supporting a door handle for rotation about an axis relative to the chassis,
• the means for supporting the door handle having a drive connection to operate the latch bolt to open and close the lock,
• means for locking the supporting means to block rotation of the door handle relative to the chassis,
• a spring coupled to the locking means, and
• means for selectively pushing the spring toward the locking means in an axial direction to urge the locking means from a handle-unlocking position disengaging the supporting means to a handle-locking position lockably engaging the supporting means.