Patent ID: 8702131

Claim:
An adjustable backset mortise lock, comprising: a housing having a front side, the housing containing a lock operating mechanism for retracting a latch bolt and extending and retracting a dead bolt and adapted to be received in a mortise in the side of a door, the housing having an upper receiver and a lower receiver on its front side, the upper receiver optionally receiving a small spacer for increasing a depth of the housing a predetermined distance, the lower receiver optionally receiving a boss of a face plate spacer for increasing the depth of the housing a predetermined distance, the latch bolt having a front end and an opposing back end and being biased to normally extend from the front of the housing, the latch bolt supported by a guide in the housing for retraction into and extension out of the housing, the guide having a threaded front end and opposing back end, the threaded front end of the guide threadingly engaging a threaded boss on the back end of the latch bolt, the distance between the front end of the latch bolt and the back end of the guide being adjustable to increase a reach of the front end of the latch bolt when the depth of the housing is increased, the dead bolt having a front side that can be extended out of or retracted into the front side of the housing, the dead bolt optionally receiving an extender to increase a reach of the dead bolt when the depth of the housing is increased, the extender secured to the front side of the dead bolt; a latch bolt driver cam for retracting the latch bolt into the housing, and a dead bolt driver cam for extending and retracting the dead bolt into the housing, the latch bolt driver cam and dead bolt driver cam operating on the lock operating mechanism for extending and retracting the latch bolt into the housing and extending and retracting the dead bolt out of and into the housing; and a face plate having openings for the latch bolt and the dead bolt to extend through, the face plate being detachably fastened to the front of the housing and adapted to be mounted on the side of the door to support the adjustable backset mortise lock in the side of a door, the front side of the housing being configured to receive the face plate spacer to increase the depth of the housing by the predetermined distance, the back side of the face plate being received by the front side of the housing or optionally received by the small spacer, the face plate spacer, and the lower receiver when the depth of the housing is increased, the face plate including first and second guide fingers extending inward from upper and lower edges, respectively, of the latch bolt opening; wherein the latch bolt has a first guide channel on its top surface and a second guide channel on its bottom surface, and the first guide channel slidably receives the first guide finger and the second guide channel slidably receives the second guide finger a latch bolt spacer for increasing a length of the latch bolt when the depth of the mortise lock is increased the predetermined distance.