Buckle for safety belts

Claim 1

QUICK-RELEASE LOCKING MECHANISM COMPRISING A FLAT SLEEVE MEMBER PROVIDING A RESTRICTED PASSAGE, A FLAT TONGUE MEMBER INSERTABLE INTO SAID PASSAGE AND HAVING A TRANSVERSE DIMENSION LESS THAN THE CORRESPONDING TRANSVERSE DIMENSION OF SAID PASSAGE SO AS TO PERMIT LIMITED MOVEMENT OF SAID TONGUE MEMBER IN SAID PASSAGE IN A DIRECTION TRANSVERSE TO THE DIRECTION OF INSERTION OF SAID TONGUE MEMBER INTO SAID PASSAGE, A FIRST CAM SURFACE FORMED ON ONE OF SAID MEMBER, A SECOND CAM SURFACE FORMED ON THE OTHER OF SAID MEMBERS AND ENGAGEABLE WITH SAID FIRST CAM SURFACE WHEN SAID TONGUE MEMBER IS MOVED IN SAID TRANSVERSE DIRECTION IN SAID PASSAGE, SAID CAM SURFACES BEING INCLINED TO SAID DIRECTION OF INSERTION SO AS TO EFFECT MOVEMENT OF SAID TONGUE MEMBER IN THE DIRECTION OPPOSITE TO SAID TRANSVERSE DIRECTION WHEN SAID TONGUE MEMBER IS URGED IN THE DIRECTION OPPOSITE TO SAID DIRECTION OF INSERTION, SPRING MEANS OPPOSING INSERTION OF SAID TONGUE MEMBER INTO SAID PASSAGE AND URGING SAID TONGUE MEMBER IS SAID DIRECTION OPPOSITE TO SAID DIRECTION OF INSERTION, LOCKING MEANS ASSOCIATED WITH SAID SLEEVE MEMBER AND MOVABLE BETWEEN A LOCKING POSITION IN WHICH IT ENGAGES SAID TONGUE MEMBER TO POSITIVELY HOLD THE SAME AGAINST TRANSVERSE MOVEMENT AND THEREBY PREVENT ITS WITHDRAWL FROM SAID PASSAGE AN D A RELEASING POSITION IN WHICH SUCH TRANSVERSE MOVEMENT AND WITHDRAWL OF SAID TONGUE MEMBER CAN TAKE PLACE UNDER URGING OF SAID TONGUE MEMBER BY SAID SPRING MEANS, AND MEANS BIASING SAID LOCKING MEANS INTO ITS LOCKING POSITION.