1. Conveying apparatus for conveyance of conveyor belts, wire link straps, conveyor boxes or the like in a heat treatment furnace, comprising a pair of similar cylindrical rollers defining a single conveying path, means mounting said rollers in generally longitudinally coextensive relation for rotation about axes disposed within a generally horizontal plane in converging relationship with respect to one another in the direction of the conveying path at an acute angle in the range of magnitude of 1* to 15*, the axes of rotation of each roller being coexistent with the axis of the cylindrical form thereof, means for simultaneously rotating said rollers about their axes of rotation in opposite directions so that their upper peripheries move with lateral components of movement which are equal and in opposite directions and longitudinal components of movement which are both in the same direction, and both of endless flexible means encircling both of said rollers including an upper flight engaging the upper periphery of said rollers and a return flight below said rollers and means for pressing said return flight upwardly against the lower periphery of said rollers.