A lock bolt extendible and retractable by movement of a power transmission assembly driven by an actuator and having a cam thereon which cams against the lock bolt to retract the lock bolt and unlock the steering column. In some embodiments, the cam has a curved surface with varying distance from the axis of rotation of the cam or pivot to improved lock bolt motion. The cam can have a gradual ramp surface to extract a lock bolt even in binding conditions of the lock bolt.