HOOK BOLT LOCK

PROBLEM TO BE SOLVED: To apply a hook bolt lock to a sliding door in thin thickness. SOLUTION: An operating plate 6 with a first rack 61 and a pair of second racks 62, 62a, a first pinion 71 engaged with the first rack 61 combined with the internal cylinder 51 of a cylinder lock 5, a pair of second pinions 72, 72a engaged with the second rack 62, locking-releasing arms 7, 7a integrally installed to the first pinions 72, 72a respectively and shaking out or shaking back the trigger 3 of an inner frame 1 through the engaging piece 44 of a driving plate 4, and the return spring 75 of both arms 7, 7a are mounted on an outer frame 2.