Abstract: A seatbelt retractor includes: a housing; a winding drum configured to wind a webbing and rotatable in a winding direction and a pull-out direction of the webbing; a lock member coupled to the winding drum to be not rotatable relative to the winding drum when a force for pulling out the webbing is less than a predetermined value and to be rotatable relative to the winding drum when the force exceeds the predetermined value; an impact energy absorber provided between the winding drum and the lock member and configured to absorb impact energy by relative rotation between the winding drum and the lock member; and a bush made of resin. The lock member includes a tubular shaft support portion, and the winding drum includes a protrusion disposed inside the shaft support portion. The bush made of resin is provided between the shaft support portion and the protrusion.

Abstract: A buckle device including: a tongue plate; and a buckle main body configured to be engaged with the tongue plate, the buckle main body including: a cover having a tongue plate guide portion; a resin release button forming a tongue plate insertion port between the tongue plate guide portion and the release button; and a frame configured to slidably support the release button and having a bottom wall and a pair of side walls, wherein protruding portions protruding inward so as to overlap with the tongue plate inserted from the tongue plate insertion port are provided on end portions of the pair of side walls of the frame on the side of the tongue plate insertion port, respectively, and wherein the release button has a front wall and at least one extending portion extending from the front wall through a space between the protruding portions and the bottom wall.

Abstract: A buckle device including: a tongue plate; and a buckle main body configured to be engaged with the tongue plate, the buckle main body including: a cover having a tongue plate guide portion; a resin release button forming a tongue plate insertion port between the tongue plate guide portion and the release button; and a frame configured to slidably support the release button and having a bottom wall and a pair of side walls, wherein protruding portions protruding inward so as to overlap with the tongue plate inserted from the tongue plate insertion port are provided on end portions of the pair of side walls of the frame on the side of the tongue plate insertion port, respectively, and wherein the release button has a front wall and at least one extending portion extending from the front wall through a space between the protruding portions and the bottom wall.

Abstract: A retractor includes a windup drum that winds webbing and a pretensioner unit that causes the windup drum to rotate in a windup direction of the webbing. The pretensioner unit includes a pinion gear configured to rotate in association with the windup drum, a piston that includes a rack for meshing with the pinion gear and causes the windup drum to rotate in the windup direction through the pinion gear, a tubular cylinder that has a circular cross-section and movably holds the piston, and a drive mechanism that drives the piston. The piston further includes, on a rear surface side of the rack, a contact surface configured to come into contact with an inner wall of the cylinder, and the cylinder has such a tube length as not to expose the contact portion in a movable range of the piston.