Principle of four-in-one button

Using the characteristic of big bead on top and small bead on the bottom. The traditional 4-in-1 buckle realizes the snap function by the cooperation between the bead head and the slingshot cup, the principle is to use the characteristic of the bead's big top and small bottom, the bead is snapped into the spring of the slingshot cup, the spring deforms in order to allow the bead to pass through the larger part of the bead, and after the bead is snapped into the slingshot cup, the spring resumes its deformation and snaps into the position of the bead of the smaller size, thus realizing the snap function of the 4-in-1 buckle.