The working of a hire forklifts in Melbourne circles around two mechanisms that is hydraulic cylinders and roller chain cylinders. Hydraulic cylinders help the forklift to lift the weight. At the base of the forklift there is an electric pump to which the handle of the lift is connected. Whenever the handle is pressed down it initiated the air pump which causes the outdoor air to enter in to the tube from where it reaches to the hydraulic cylinders. The structure of hydraulic cylinder is similar to the tube with one end closed and on the other end there is piston that is flexible enough to move in and out. Due to this reason the air is not able to get out and is trapped in it without any sort of leakage. The gas trapped in the cylinder creates a pressure inside which causes an upward force. This force then helps to move the piston upwards. This mechanism gives rise to the volume and decrease the pressure. A state of physical equilibrium is reached which exerts an equal force applied by the gas. This force then helps to lift up the load.
When the operator needs to lift up the load the handle is pushed in forward direction which allows the outdoor air to enter the cylinders and exert force whereas if the operator wants to lower down the load the handle is pushed in backward direction which causes the excess air inside the cylinders to escape and hence releases the force applied to lift it due to which it lowers down itself.
The second method is use roller chain cylinders. There are vertical structures referred as mast and hydraulic pistons are attached to these mast. At the top of the mast there is the fulcrum of the chain pulleys that are mounted to the body of the forklift truck. One side of the pulley is designed in such a way that it is fixed and is not moveable and this side is attached to the frame of the truck. Therefore, whenever the piston is pressed in up direction, the gear mounted on the mast exerts the force in an opposite direction of roller chains. The benefit of this mechanism I that it can lift the load to a relatively high height than the hydraulic cylinders. The use of roller chains makes it easy to lift up the load to high height without even using the cylinder. If this much height is desired with hydraulic cylinders then very large cylinders are required.