Patent attributes
A mortise lock includes a chassis mounted in a mounting hole of a door and an outside handle assembly mounted to a side of the chassis. The outside handle assembly includes an outside spindle having a first end partially received in the chassis and operably connected to at least one bolt of the chassis such that rotation of the outside spindle causes retraction of the bolt. The first end of the outside spindle includes a perimeter groove, forming a fragile portion. An outside handle includes an end securely connected to a second end of the outside spindle to turn therewith. The fragile portion of the outside spindle is broken when an excessive force is applied to the outside handle. Thus, unauthorized opening of the door by forcibly turning the outside handle is prevented. Further, the mortise lock can be easily installed, and the cost of the mortise lock is cut.