Abstract: Small diameter rotary drill bits using rolling disc cutters. Novel small diameter rotary drill bits with detachable pedestal mounted rolling disc cutters are provided. The bit body has a plurality of longitudinal edge mounting slots located at preselected angularly spaced apart locations. Preferably, the slots each have an upper protective ledge and downwardly extending sidewalls. A set of peripheral pedestal mounts each having a mounting portion sized and shaped to fit into a preselected mounting slot are provided and each is detachably mounted in its preselected mounting slot. In one embodiment, the longitudinally extending slots further comprise a wedge shaped edge portion, and the pedestal mounts have a complimentary angularly shaped portion, so that when the pedestal mount is brought into a close fitting relationship with the longitudinal slot, the pedestal mount and the longitudinal slot are tightly and securely interfitting.

Abstract: An improved disc type rolling rock cutter, and novel cutterheads employing such cutters. A rock cutter with an improved, simplified structure, with compact bearing, and smooth, rounded blade shape is disclosed. The design incorporates a cutter ring, bearing, and seal into a single cutter ring assembly. The cutter may be assembled and disassembled for rework by a single worker with simple hand tools. Replacement of worn out cutter rings is done quickly and easily by removing the old ring assembly and then sliding a new ring, bearing, and seal assembly on to the cutter shaft. This simplified assembly is achieved by using a comparatively large shaft which is normally in the range of 40-50% of the ring diameter. The shaft design is sufficiently robust to permit a cantilever mount of the cutter. The unique configuration allows 30,000 lbs. or more thrust to be applied to a 5 inch diameter miniature disc.

Abstract: An improved disc type rolling rock cutter, and novel cutterheads employing such cutters. A rock cutter with an improved, simplified structure, with compact bearing, and smooth, rounded blade shape is disclosed. The design incorporates a cutter ring, bearing assembly, and seal assembly. The cutter may be assembled and disassembled for rework by a single worker with simple hand tools. Replacement of worn out cutter rings is done quickly and easily by removing the old ring assembly and then sliding a new ring, bearing, and seal assembly on to the cutter shaft. This simplified assembly is achieved by using a comparatively large shaft which is normally in the range of 30-50% of the ring diameter. The shaft design is sufficiently robust to permit a cantilever mount of the cutter. The unique configuration allows 30,000 lbs. or more thrust to be applied to a 5 inch diameter miniature disc. This capacity permits single disc cutter technology to be applied to smaller bits or cutterheads than previously possible.

Abstract: An improved rolling disc type cutter, and novel cutterheads employing such cutters. The cutter includes a washer surface and a cutter ring assembly. The cutter ring assembly further includes an annular cutter ring with an interior annulus defining portion and an outer ring portion. A bearing assembly substantially fits into the annulus of the cutter ring in a close fitting relationship with the shaft, so that the cutter ring may rotate with respect to and be supported by said shaft. The bearing assembly includes a bearing and a seal which fits between the washer surface and the cutter ring to form a lubricant retaining seal for the interior annulus portion of the cutter ring. A retainer assembly is used to retain the cutter ring assembly on the shaft, and a cap seals the interior annular portion of the cutter ring assembly so that, in cooperation with the seal and the cutter ring, a lubricant retaining chamber is provided.

Abstract: A two component field mix explosive composition comprising a first solid component comprising ammonium nitrate or mixtures of ammonium nitrate with ammonium perchlorate, and a second liquid component comprising as a first ingredient hydrazine, a second ingredient which is water, alcohol or a mixture thereof, and as a third ingredient ammonium nitrate in an amount no greater than about one-sixth of the total weight of the second component. At the site of use the liquid component is poured into the solid component to form an explosive composition. This composition is detonable in elongate packages as small as one inch in diameter, by use of a blasting cap.

Abstract: An explosive cartridge for use in an explosive column train by end to end coupling of a plurality of cartridges. Each cartridge comprises a cylindrical containing shell having an open rear end in which is a closure plug. In the pre-mix condition, the cartridge contains a first solid component of a two part explosive. In field use the closure plug is removed and a liquid second explosive component is poured into the cartridge and the plug reinserted to form a sliding watertight seal with the cartridge. When several of the cartridges are joined in end to end relationship to form the explosive train, the nose end of one cartridge moves the plug of the adjacent forward cartridge inwardly to take up the slump in the explosive composition and maintain the closure plug seal.