US Patent 7631401 Buckle structure of waist belt

A buckle structure includes a housing including a top plate and two side plates, a sliding wedge and a pivotal piece. Each side plate has a guiding slot. The sliding wedge is positioned below the housing and has projection portions projecting from its two sides. The projection portions are fit into corresponding guiding slots of the housing, and stoppers are positioned on top surface of the sliding wedge. The waist belt is fastened by the stoppers positioned on top surface of the sliding wedge so that the waist belt will not be loosed. Connection portions are extending from the top plate, and each connection portion has a through hole at its midpoint. Pivotal pins are extending from the pivotal piece and correspond to the through holes of the two connection portions. The pivotal piece is formed with the two pivotal pins so structure is simplified and cost is lowered.