Cart

A cart, comprising a pull rod mechanism, a folding bracket mechanism, and a pull rod locking apparatus, wherein

• the pull rod mechanism comprises main pipes and sub-pipes connected telescopically;
• one end of the sub-pipe is inserted into the main pipe;
• and two main pipes and two sub-pipes are provided;
• the folding bracket mechanism comprises a bearing frame, connecting rods, and connecting elements;
• the bearing frame is rotationally connected to the main pipe;
• the connecting rod is rotationally connected to the main pipe;
• the connecting element is rotationally connected to the bearing frame and the connecting rod simultaneously;
• the connecting element is fixedly connected with a support frame;
• a transverse rod is arranged on the main pipe;
• the transverse rod is rotationally connected with rollers;
• the main pipe, the bearing frame, the connecting rod, and the connecting element form a four-rod mechanism;
• the bearing frame is detachably connected with a support plate;
• a plurality of buckles are arranged at a bottom of the support plate;
• the whole bearing frame is U-shaped;
• and a shape of the buckle is adapted to a cross-sectional shape of the bearing frame;
• and
• the pull rod locking apparatus comprises a mounting frame, sliding rods, and a knob;
• the mounting frame is fixedly connected between the two main pipes;
• the mounting frame is symmetrically provided with two sliding grooves;
• two sliding rods are provided and are slidably connected in the two sliding grooves respectively;
• the knob comprises a lock block;
• the lock block is circumferentially provided with far ends and near ends;
• a distance between the far end and a rotation axis of the knob is greater than a distance between the near end and the rotation axis of the knob;
• two far ends and two near ends are provided, and both the two far ends and the two near ends are symmetrical around a center of the rotation axis of the knob;
• and when the knob is rotated until the far end abuts against the sliding rod, an end of the sliding rod tightly abuts and locks the sub-pipe.