Abstract: A blast hole drill comprising a mast including two parallel mast cords, a carriage, and a rotary head mounted on the carriage and adapted to engage a drill pipe. The rotary head includes a drive pinion on a rack on one of the mast cords, and the drive pinion is on one side of at least one of the mast cords. A backup wheel assembly is on the opposite side of the respective mast cord opposite the pinion and includes a wheel holding assembly support rotatably supporting a backup wheel, a yoke having an opening through the yoke, a plunger threadably received in the yoke opening, the wheel assembly support being slidably received on the plunger, and Belleville washers extending around the plunger and between the yoke and the wheel holding assembly support, the Belleville washers extending between an abutment on the plunger and the wheel holding assembly support.

Abstract: A blast hole drill comprising a mast including two parallel mast cords, a carriage, and a rotary head mounted on the carriage and adapted to engage a drill pipe. The rotary head includes a drive pinion on a rack on one of the mast cords, and the drive pinion is on one side of at least one of the mast cords. A backup wheel assembly is on the opposite side of the respective mast cord opposite the pinion and includes a wheel holding assembly support rotatably supporting a backup wheel, a yoke having an opening through the yoke, a plunger threadably received in the yoke opening, the wheel assembly support being slidably received on the plunger, and Belleville washers extending around the plunger and between the yoke and the wheel holding assembly support, the Belleville washers extending between an abutment on the plunger and the wheel holding assembly support.

Abstract: A blasthole drill includes a drill pipe seal to seal an opening around a drill pipe which extends through a drill deck in order to substantially prevent drilled ground material, such as dust and rock chips, from escaping into the atmosphere. The seal comprises a pliable membrane which is capable of sealing the opening around the drill pipe and which also allows the drill pipe to be positioned in variable drilling positions while still providing the necessary sealing arrangement. First and second flexible seal flaps are connected to the drill deck in an overlapping fashion. The seal flaps are separable to allow the drill pipe to pass therethrough, but otherwise remain overlapped. The flexible seal flaps substantially seal the opening around the drill pipe in any operable position of the drill pipe. To increase the sealing effectiveness, additional pairs of similar seal flaps may be added.

Abstract: A crawler shoe for the crawler tracks of a heavy-duty mining shovel or the like weighing 500 tons or more comprises a solid main body formed of high strength tempered steel plate (i.e., 100,000 P.S.I. yield strength), integrally formed projections, recesses, and pin holes on the body for detachably and articulately connecting the shoe to an adjacent shoe, end gussets welded to and projecting from the lateral sides of the body, a roller path plate of moderately hard high strength steel (i.e., between about 300 and 350 B.H.N.) welded to the upper surface of the main body, a pair of hollow drive lugs welded to the upper surface of the body on opposite sides of said roller path plate and formed of cast austenitic manganese steel, and a belly pan of high strength high hardness abrasion-resistant steel plate (i.e., between about 341 and about 391 B.H.N.) welded to the underside of the main body and the gussets.