Lock unit

A two-part lock unit for locking an overhead garage door and for mounting at a suitable position on or adjacent the overhead garage door, the two-part lock unit comprising:

• a first part of the two-part lock unit being a lock assembly having a locking element and a drive receiving portion operatively associated with the locking element, the first part coupled to a surface of the overhead garage door or an adjacent wall or rail;
• and
• a removable second part of the two-part lock unit being a drive unit configured to be connected to the lock assembly, wherein the drive unit is physically separable from the lock assembly, the drive unit having a motor and being configured to move the locking element of the lock assembly from a locked position, in which movement of the overhead garage door is impeded, to an unlocked position, in which movement of the overhead garage door is allowed, the drive unit including a driving element that interfaces with the drive receiving portion of the lock assembly to move the locking element from the locked position to the unlocked position when the first and second parts are connected together, said interface between the driving element and the drive receiving portion being a keyed interface having only a single relative orientation of engagement so that the driving element and the drive receiving portion define an operational position of the drive unit and the lock assembly at a given time;
• wherein the first part of the two-part lock unit being the lock assembly includes an anti-backdrive mechanism configured such that when the drive unit is physically separated from the lock assembly, the locking element cannot be forcibly moved from the locked position to the unlocked position by an external force applied on the locking element in a direction which would otherwise drive it toward the unlocked position.