The tipping mechanism is the heart of a three way tipper construction truck. Tipping mechanisms work basically on the following:
Hydraulic cylinder : A hydraulic cylinder is placed below the body of truck longitudinally at one end of the truck, and the piston end of the hydraulic cylinder is connected by the means of a pivot joint to the chassis of truck.

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In the forward stroke of the cylinder, it pushes the truck body upward thus gives neccessory lift for tipping dumping. So, in the forward stroke of the cylinder, the truck is unloaded. In the return stroke of the cylinder the body of the truck comes to its original position.
Hinge Joint:The other bottom end of the body of the truck is connected by a hinged joint with the chassis.So, when the hydraulic cylinder pushes the body in it's forward stroke the entire body gets tilted about the axis of the hinged joint and the material gets unloaded and by the return stroke of the hydraulic cylinder body comes and seat to its original position with respect to the hinged axis.
But in this types of tipper can unload materials only at the backside of the tipper.

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3-way tipper can overcome this problem, as it can unload material on three sides.