Commonly used two wheeled trucks include hand-propelled trucks (also known as tiger trucks), frame trucks, and funnel trucks used to transport bulk materials. One of the three wheelers and two of the four wheelers have rotating casters that can rotate around a vertical axis. The rotating caster can automatically adjust to the direction with the least driving resistance with the change of the moving direction of the vehicle.
Carts of different purposes have different body structures. Most universal trolleys have loading platforms. Special trolleys are of various structures, some of which are made of box like bodies, suitable for carrying light weight and convenient loading and unloading items; some of the bodies extend out of the supports to facilitate the placement of rods, shafts, pipes and other parts; some of the body shapes are fully matched with the goods, such as gas cylinder cars; some are small, foldable and portable; in order to facilitate the loading and unloading of barrel like goods, such as barreled liquid and paper roll, The car body is provided with two flat plates forming a low inclined plane to facilitate the rolling up and down of the barrel shaped goods, such as the barrel shaped goods loading and unloading vehicle. Modern handicrafts are equipped with rolling bearings and wheels are made of solid tires or pneumatic tires.
