Abstract: A two-way free-wheeling clutch is formed between a drive shaft and a driven shaft concentric with and encircling at least a portion of the drive shaft that is formed by axially extending substantially chord forming portions. The chord forming portions cooperate with circular bearings interposed between the portions and a circumferential surface of the encircling portion of the driven shaft to drive the driven shaft from the drive shaft. Drive of the driven shaft by the drive shaft is obtained by relatively positioning the bearings and the portions so the bearings are toward the radial extremities of their respective chord portions a driving wedge is formed with the inner circumferential surface of the driven shaft. When the portions and the bearings are shifted to relatively position the bearings closer to the centre of the chord forming portions i.e. minimum radial position on the chord free rotation of the driven shaft freewheeling of the driven shaft is permitted.

Abstract: An improved drill rod magazine for storing and moving them sequentially into a dispensing position is comprised of a pair of spaced arms each with an open jaw in which the drill rods are positioned in parellel, side by side relationship. The arms are moveable from a storing position into at least two dispensing positions, in a first of which one of the rods in the jaws is aligned with the hammer of the drilling machine and in the second of which another rod (the adjacent rod) is aligned with the hammer. Each of the jaws is provided with a clamp to clamp the rods contained therein to prevent rotation of each rod for threading of the hammer into an adjacent coupling on the rod. The rod is released for rotation while retaining same within the jaws so that the rod coupled to the hammer may be rotated and advanced by the hammer to thread same into an aligned coupling, after which the arms are retracted to their storage position. For uncoupling the procedure is reversed.