Idler spacing: Spacing of idlers in the loaded run is a function of bulk weight of materials and width of belt. Selection of idler spacing has been further discussed in section 6 (c) Co Pulleys: At each of the two ends of a belt conveyor, one large diameter pull is installed against which the belt turns and changes terminal or bend pulley. Drive is imparted to belt through friction by one of the emi- nal pulleys called drive pulley. As the conveyor belt passes around these bend pulleys the direction. These pulleys plies of the belt are elongated in proportion to the distance of the ply form center of the pulley. The differential elongation of bonding between two plies. Larger the pulley. less is differential ply over the other is tken up by the rubberized plies hence less tendency to ply separation. This is the reason the bend pulleys are made elongation between The conveyor pulleys are either fabricated from rolled steel plates or of cast iron construc tion. The central steel haft is keyed into the pulley drum and then the finished dimensions are machined. The pulleys are generally given a crowning at the face for keeping the belt the centre of the pulley. The face length is generally 100 mm to 200 mm more than the belt width. The surface of the pulley may be left bare smooth, or may be coveed up to a thicknes of 6 to 12 mm by rubber, polyurethane or ceramic layer with hemngbone pattemed goowesto increase the friction between the pulley and belt. The pulleys are mounted on heavy duty antifriction berings in suitable bearing housings Drives for Belt Conveyors: The belt conveyors are generally driven at te head end pulley, where material is discharged. The drive pulley is connected to the drive motor through suitable speed reduction gear box and flexible shaft couplings. Drive of an inclined conveyor necessarily includes a braking device which prevents downward movement of the loaded belt in case of power failure of the motor (e) Take-ups or Belt Tensioning Devices: Endless conveyor belt after being treaded through the entire length of the conveyor need to be tightened so that sufficient frictional force is developed between the drive pulley and the belt. to make the belt move. Belts working under tension invariably gets elongated with time, which needs to be taken-up to maintain