Roller conveyors may be a powered(Live) or non-powered(Gravity). The non-powered conveyors are referred to as gravity conveyors by inclining the roller section. The powered roller conveyors are either belt or chained driven. The rollers are connected individually to the drive shaft. The roller conveyors are well suited for accumulating loads and merging and sorting materials. Because of the rollers the materials being moved on these conveyors must have a rigid riding surface.