Abstract: The driven head shaft of a drag elevator type conveyor is mounted at the roller end of a shaft mounting frame which is in the nature of a first class lever. A mid-portion of the shaft mounting frame is mounted onto an upper end portion of the conveyor main frame for pivotal movement about an axis which is parallel to the axes of both the head shaft and the tail shaft. A turnbuckle is interconnected between the upper portion of the shaft mounting frame and an upper portion of the main frame. The shaft mounting frame end of the turnbuckle is connected to a mid-portion of a lever arm which is at its upper end pivotally attached to the shaft mounting frame. The lower end of such lever rests on a pair of laterally spaced apart compression springs. The turnbuckle provides a way of adjusting the tension in a pair of roller chains which are portions of an endless carrier which extends between and is mounted on the head shaft and the tail shaft.