Buckle

A buckle comprising:

• a plug;
• and
• a socket configured to be engaged with the plug,
• wherein the plug comprises:
• a plug-side base part to which a belt-shaped member is attached;
• a pair of leg parts extending in parallel with each other from both end portions of the plug-side base part in a width direction;
• and
• a pair of engagement protrusions protruding in an upward and downward direction from each of leading end portions of the pair of leg parts,
• wherein the socket comprises:
• a socket-side base part to which the belt-shaped member is attached;
• an upper plate and a lower plate extending from the socket-side base part;
• upper side wall parts protruding downwardly along both side edges of the upper plate in the width direction;
• lower side wall parts protruding upwardly along both side edges of the lower plate in the width direction;
• engagement stepped portions capable of being respectively engaged with the pair of engagement protrusions of the pair of leg parts inserted between the upper and lower plates;
• slits formed between the upper side wall parts and the lower side wall parts and each having an end portion opened at a plug insertion-side so that the pair of leg parts can be inserted therein;
• and
• guide surfaces formed on inner surfaces of the upper side wall parts and the lower side wall parts and configured to guide the pair of engagement protrusions of the pair of leg parts inserted between the upper and lower plates to the engagement stepped portions,
• wherein when the plug is inserted into the socket, the engagement protrusions of the leg parts of the plug comes into contact with and are guided by the guide surfaces of the socket,
• wherein the plug comprises a fitting rod arranged between the pair of leg parts and formed in parallel with the pair of leg parts,
• wherein the socket comprises a fitting hole arranged between the upper and lower plates and into which the fitting rod is fitted,
• wherein protruding pieces are formed at central portions of both side surfaces of the fitting rod in the upward and downward direction,
• wherein the fitting hole is configured by the upper plate, the lower plate, and a pair of right and left plate parts formed so as to connect to the upper plate and the lower plate, and
• wherein end faces of the pair of right and left plate parts at the plug insertion-side are formed with concave parts to which the protruding pieces are fitted.