Patent ID: 7520034

Claim:
A seat belt system comprising: a first buckle unit including a first tongue plate and a first buckle body; and a second buckle unit including a second tongue plate and a second buckle body, the first and second buckle bodies respectively including: frames; ejectors slidably mounted on the frames in a direction in which the tongue plates are inserted, while being biased in a direction in which the tongue plates are released; hook members pivotally mounted on the frames, the hook members pivoting when the tongue plates are inserted to make engagement with engagement holes formed at the tongue plates; and release buttons for breaking engagement between the hook members, and the tongue plates, a distance from an insertion front end to the engagement hole of the first tongue plate being longer than a distance from an insertion front end to the engagement hole of the second tongue plate, the ejectors respectively including abutment parts pushed by the tongue plates when the tongue plates are inserted, the ejectors further respectively including pushing parts in contact with the hook members when the tongue plates are most deeply inserted to force the hook members to pivot in a direction for making engagement with the tongue plates, a distance from the abutment part to the pushing part of the ejector of the first buckle body being shorter than a distance from the abutment part to the pushing part of the ejector of the second buckle body; restriction means for preventing the ejector of the first buckle body from reaching a position for making engagement when the second tongue plate is inserted into the first buckle body, and the ejector of the first buckle body including suppression-specific projections for preventing pivotal movement of the hook member in a direction for making engagement until the ejector reaches a position for making engagement between the first tongue plate and the hook member.