MECHANISM FOR ERECTLY HOLDING STOOL SEAT

PURPOSE:To prevent the generation of operating sound by receiving a restraining ring by an elastic body at the time of the collision of the restraining ring with a restraining base body because of a spring. CONSTITUTION:At the time of erecting a stool lid 1 by utilizing the rotation and movement in the axial direction of a restraining ring 11, the rotation of the restraining ring 11 is suppressed by making a step portion 11e hit against an engaging projection 10c, to hold the stool seat 1 in an erect condition. The restraining ring 11 is moved in the axial direction with respect to a restraining cap 10 and, when the step portion 11e falls down onto the engaging projection 10c after the restraining ring 11 traveled in the arrow direction, the restraining ring 11 is suddenly pushed off by a leaf spring 12 colliding against the restraining cap 10. In this case, even if the restraining ring 11 is moved in its axial direction, the end face of the annular projecting portion 11b of the restraining ring 11 collides only against an O-ring 13 and the restraining ring 11 is elastically received.