Patent attributes
A folding structure for a trolley includes at least two main poles and a movable member. The main poles are connected to a carrying platform having an operating rod, two roller sets, and a base that are motionally linked. A transverse plate is attached to upper ends of the main poles. The movable member is slidably mounted on the main poles and has a pull rod. The pull rod extends beyond the transverse plate for an extension distance. To prepare the trolley for use, the operating rod is pushed downward so that the roller sets expand in a horizontal direction and the base is laid down. Then the pull rod is set for its largest extension distance to facilitate a user's pulling trolley. After use, the trolley can be easily folded by lifting the operating rod that in turn drives the roller sets and the base to retract.