A cutting device includes a lock device for locking and unlocking a cover against a cover support. The cover includes a first cover removably mounted to the cover support and a second cover removably mounted to the first cover. The lock device is operable in a first mode, a second mode and a third mode. The first mode prevents the first cover from being removed from the cover support and prevents the second cover from being removed from the first cover. The second mode permits the first cover from being removed from the cover support but prevents the second cover from being removed from the first cover. The third mode permits the second cover to be removed from the first cover.