Abstract: A flat flywheel body fabricated by water jet cutting has radial spoke pairs with a display hanger slot in between and flywheel weights circumferentially extending at their peripheral ends. Resilient thin attachment rims for the saw blades are circumferentially connecting the flywheel weights and provide together with them a continuous peripheral sliding surface. A two piece arbor is connected to a central continuous spline of the flywheel body. The peripheral saw blades are bent into concentric curvature by radially clamping them onto the blade attachment rims.

Abstract: A die head retaining mechanism for installing or removing a die head in a power drive for thread cutting operations is described. The mechanism comprises a cam and follower arrangement with a face gear having at least one locking jaw disposed in a slot provided on the face of the face gear oriented away from the housing. The mechanism also comprises a drive ring having a collection of cam profiles to control the movement of the locking jaws. The mechanism also comprises at least one compression spring disposed in corresponding groove(s) on the face gear. The compression spring is typically preloaded to keep the locking jaws in a locked position. The mechanism also comprises a bearing provided between the housing and the face gear. The bearing is locked in place by a retaining ring. A locking plate, spring washers, and screws are used to secure the assembly of the die head retaining mechanism on the power drive.

Abstract: A feed beam for a rock drill has a drill steel centralizer at its front end. The centralizer comprises a thick, cylindrical rubber sleeve which has a clearance to the drill steel. An annular piston is arranged to axially compress the rubber sleeve axially so that it is radially deformed into contact with the drill steel to centralize the drill steel. The centralizer is built together with a dust collecting hood.