A pivotal supporting device includes a supporting base, a pivot shaft disposed on the supporting base, a supporting arm having a plate attached to the pivot shaft, two levers having one end portions pivotally attached to the plate with pivot pins, a panel pivotally attached to the other end portions of the levers with pivot axles for forming a parallelepiped structure with the levers and the plate, and a spindle attached to the panel, a carrier attached to the spindle, and a remote member attached to the carrier. One or more spring biasing elements are engaged onto the pivot shaft and one or more spring biasing members are engaged onto the spindle and one or more spring biasing components are engaged between the pivot shaft and the spindle.