Over-and-under type supporting seat

Over-and-under type supporting seat, it includes support, two guide arms, slider, first elastic component and rolling mechanism. The support is located perpendicularly to two guide arms. Slider both sides activity respectively are linked to two guide arms, and first appearance room is seted up to the slider rear side, and the slider front side is equipped with the screw with first appearance room intercommunication. First elastic component one end is fixed in the support, and the other end supports holds the slider. Rolling mechanism includes that pedestal, rolling member, second elastic component and lock compel, and wherein, the pedestal holding is indoor in first appearance, and the rolling member is located pedestal and part and is exposed first appearance and outdoor and replace the support, and the pedestal is located to the second elastic component, and the lock compels that the screw is locked to the piece and the part gets into first appearance room and replaces the second elastic component. The utility model discloses use rolling mechanism to provide the weight that the cushion effect resisted the object that the slider connects and the produced moment of length of connecting piece, thus can prevent because of moment and lead to the problem that the slider slided and have some setbacks or block.