Patent ID: 6912880

Claim:
A combination lock having a second lock mechanism comprising: a lock body comprising at least a push-button and a lock tongue in relation with each other, the lock tongue having a locking position and a releasing position; a stopping member, positioned in the lock body, having a first position for constraining the lock tongue in the locking position and a second position for releasing constraint of the lock tongue; a first lock mechanism comprising a plurality of dials and a shifting plate installed in the lock body, the shifting plate and the dials moving correspondingly, the shifting plate having a clamping position for constraining the stopping member to remain in the first position and a unlocking position for releasing the stopping member from being constrained; and a second lock mechanism comprising a sleeve and a linking member installed in the lock body and in relation with each other, the sleeve having a keyhole for allowing a key to be inserted and for being rotated by the key such that the linking member is shifted and forces the stopping member to change positions.