What Is a Trolley?
A trolley is a device used to transport products, raw materials, etc. It has wheels under a flat plate on which loads are loaded and pushed by a handle.
By loading cargo on the flat plate, more cargo can be loaded than if it were carried by hand, and once it starts moving, it can be moved smoothly because the resistance between the wheels and the ground is reduced.
While hand-pushed carts are the most common type of cart, some electric carts are also available to assist in work.
Uses of Trolleys
Trolleys are used everywhere to transport relatively lightweight loads.
The most common type is the single-sided trolleys with a handle on one side. In the transportation and retail industries, box trolleys are often used for moving and storing high loads, and double-sided trolleys with handles on both sides are used for transporting heavy loads.
Some trolleys are developed not for pushing as they are, but for towing with forklifts, etc. for the purpose of transporting heavy loads.
Principles of Trolleys
The behavior of trolleys can be explained by the equations of motion in physics.
When trolleys are loaded with a load and pushed, it will initially remain stationary due to the weight and the frictional force between the wheels and the ground. It starts moving when the applied force exceeds the starting resistance force.
Since the starting resistance force is proportional to the ground contact area of the wheel, the harder the wheel is that is less deformed, the less the resistance force becomes, and the larger the wheel is, the more the torque increases, allowing the wheel to move with less force. The design is made in accordance with the intended use.
Although trolleys can transport heavy loads, when the load is stacked high and the center of gravity is high (as indicated by the height of the handle), the moment of rotation around the center of gravity is activated, causing the load to collapse or topple over due to the difference in level or inclination of the location where it is used. The tread and wheelbase of the wheels are designed according to the expected weight, and the use of trolleys with stoppers is recommended on sloping terrain.