Abstract: Disclosed is an exchangeable self-adjusting device for use in a belt, in which a strap is properly extended due to a slight abdominal motion, and a wearer can easily exchange the buckle to follow the fashion. The device includes a cover 10 being movable left and right, a slidable body 20 inserted into a bottom of the cover 10, and a bottom plate 30 hinged to one portion of a bottom of the body 20 by means of a hinge 32. The cover 10 includes a cover hook 12 formed at a front thereof and inserted into a buckle hook 51 provided at a rear of a buckle 50, and a leaf-spring hooking boss 11 with a hooked groove 11a formed at its center. The body 20 includes detachable bosses 21 protruded from both sides thereof, a roller fixing shaft 23 formed at a center of a bottom thereof for rotatably fixing a roller 70, and a hinge protruded from both sides of the rear thereof towards the bottom and having a hinge hole 22.

Abstract: Disclosed is an exchangeable self-adjusting device for use in a belt, in which a strap is properly extended due to a slight abdominal motion, and a wearer can easily exchange the buckle to follow the fashion. The device includes a cover 10 being movable left and right, a slidable body 20 inserted into a bottom of the cover 10, and a bottom plate 30 hinged to one portion of a bottom of the body 20 by means of a hinge 32. The cover 10 includes a cover hook 12 formed at a front thereof and inserted into a buckle hook 51 provided at a rear of a buckle 50, and a leaf-spring hooking boss 11 with a hooked groove 11 a formed at its center. The body 20 includes detachable bosses 21 protruded from both sides thereof, a roller fixing shaft 23 formed at a center of a bottom thereof for rotatably fixing a roller 70, and a hinge protruded from both sides of the rear thereof towards the bottom and having a hinge hole 22.