Abstract: A ball joint tractor with simple structure and convenient operation is disclosed. When docking is required, it will realize automatic locking, and there is no need for separate personnel to operate. Docking can be completed without getting off the vehicle. The pull ring spring plunger used in the disclosure can be directly inserted into the tractor from the outside of the tractor. When the pull ring spring plunger is damaged, it can be replaced directly without replacing the whole ball joint tractor, which improves the service efficiency of the equipment and avoids the failure of the whole ball joint tractor due to poor spring pin. In the disclosure, by placing the fixing ball in the ball joint groove for locking, the risk of automatic unlocking is avoided, and the safety performance is high and the traction effect is good.

Abstract: An electric sofa for recreational vehicle is provided with a sofa combined cabinet. The sofa combined cabinet includes a first sofa cabinet, a second sofa cabinet and a third sofa cabinet. The sofa combined cabinet is of U-shaped distribution. The third sofa cabinet is provided with a telescopic plate, the telescopic plate is located at one side of the third sofa cabinet close to the second sofa cabinet, the telescopic plate is provided with a telescopic plate driving device fixed on the floor of the recreational vehicle. The third sofa cabinet is provided with a sofa cabinet driving device. The bottom of the third sofa cabinet is provided with a slide rail device, the telescopic plate is unfolded or contracted under the driving of the telescopic plate driving device, the third sofa cabinet is driven by the sofa cabinet driving device to move along the slide rail device.