Abstract: A shock absorbing assembly for a drilling machine utilizing a down hole hammer having a driver member for receiving input forces, a driven member for transmitting forces from the driver member to an attached drill string, and a resilient member which is placed under tension and elongated when downward forces are applied. The resilient member under tension receives and dissipates shocks and vibrations.

Abstract: A guide bushing mountable in a supporting sleeve in the deck of a blast hole drill for guiding a drill string extending through the sleeve, the bushing having a tubular core providing a cylindrical axial bore adapted to receive and guide the drill string, the core having a flange by which it is supported in the supporting sleeve, and in which a resilient, elastomeric cushion mounted on the exterior of the core serves to cushion transverse movements of the bushing within the supporting sleeve. Preferably, the bushing is formed of two halves fastened together by hinges, so that it can be opened and laterally installed around the drill string.

Abstract: A shock absorbing rotary drive coupling unit for drivingly connecting a tubular drive shaft to an axially aligned tubular driven shaft of a rotary blast hole drill. The unit has an annular body of resilient elastomer sandwiched between and bonded to end plates, with lugs and fasteners for connecting the end plates, respectively, to the drive shaft and the driven shaft.