Drive mechanism for electronic deadbolt

An electronically-controlled manually-actuated deadbolt lock is provided. The electronically-controlled manually-actuated deadbolt lock includes an internal spring-actuated coupling mechanism that, when a user is authenticated, the coupling mechanism is placed in an engaged position that allows a deadbolt latch to be moved into a locked or unlocked position responsive to a manual rotation of a turn piece. Because the deadbolt latch is manually driven, a warped door condition can be overcome. Additionally, because the deadbolt latch is manually actuated, operation of the electronic motor may be decreased, which may increase battery life.