Abstract: Drilling means of the type having a pilot bit, a reamer and a guidemember mounted in the bottom end of the casing tube, and which transmits impacts to the casing. The guide member is snugly enclosed in the thickened mouth portion of the casing tube and has a plurality of channels which are segments of a spiral through which the drilling debris is discharged upwardly to the casing tube.

Abstract: A device for lubricating rotary drill bits of the type comprising a roller cutter (14) which is rotatably carried by means of a bearing system (15, 16, 17, 18). Fluid is supplied to the bearing system for cooling and/or cleaning thereof through a passage (31, 32, 33; 51, 61), and a lubricant is delivered to said passage from a body (31; 39) of porous material, which is soaked in lubricating means. For purposes of controlling the supply of lubricating means the porous member forms a fraction of the inner wall of said passage.

Abstract: The present invention relates to a boring device for boring internal surfaces of hollow workpieces of the kind which comprises radially adjustable insert-provided holders, there being provided pressure means, such as steering pins so as to effect radial adjustment of the insert holder from an outer active working position to an inactive position. The radial adjustment occurs by having each insert holder via said steering pins supported against a bushing of non-circular cross section actuatable by a shaft member centered within the bushing, said bushing upon its rotation effecting said radial adjustment.

Abstract: An improvement in a cemented carbide is disclosed. Molybdenum, tungsten and carbon are mixed and heated in a nitrogen-containing atmosphere to form a tungsten-molybdenum carbonitride (Mo, W) (C, N) having the structure of tungsten carbide. The molybdenum-tungsten carbonitride is mixed with a binder metal (and, if desired, another hard material) and sintered in a conventional manner to form a dense, substantially pore-free material which is similar in a number of properties to the more expensive tungsten carbide.

Abstract: A mounting device for machining tools, preferably milling cutters, which are secured to the mounting device (11, 30) by means of a connecting means (12). For making possible a rapid exchange of machining tools (10), such as milling cutters having different diameters and entering angles, the mounting device comprises an adapter (11, 30) which is attached to a drive spindle (13) and carries the machining tool (10), and an operating means (15; 31, 41), arranged in the adaptor (11, 30) and manually shiftable between a blocking position and a releasing position. In its blocking position the operating means (15; 31; 41) actuates a blocking means (19; 33; 38) to engage the machining tool (10) for carrying same when the connecting means (12) is loosened. In its releasing position the operating means (15; 31; 41) allows removal of the machining tool (10) from the adapter (11, 30).

Abstract: The invention provides a cutoff tool that enables more narrow grooves to be produced in comparison with cutoff tools of conventional design. The tool consists of a holder 10 having a recess 12 in one side face 11 in which a cutting insert 13 is located and clamped by means of a center screw 14 threadably engageable with the holder 10. According to the invention the insert 13 is of polygonal shape and provided with a protruding central portion 20, which is received in said recess 12 in the holder, whereas the remainder of the insert extends laterally from the holder for cutoff purposes. The protrusion 20 is polygonal in shape in correspondence with the shape of the insert but angularly offset therefrom.

Abstract: Ceramic materials intended for cutting and consisting of aluminum oxide with additives of hard carbides or nitrides, particularly titanium carbide, have up to now, because of their sintering inertia, in general been pressure sintered to obtain satisfactory properties. According to the present invention a ceramic alloy of excellent technological properties has been formed and comprises principally Al.sub.2 O.sub.3 and hard nitrides or carbonitrides, such as TiN or Ti(C,N) in which the alloy contains from 2 to 95 v/o of an Al--O--N-compound, such as nitrogen stabilized aluminum oxide with cubic or nearly cubic structure.

Abstract: A rotary drill bit comprising at least one roller cutter (12) which is rotatably supported over bearing means (14, 15, 16) and provided with cutting means (13). The bearing means comprises a radial friction bearing (16) with a bearing element (25) of wear resistant material, such as hard metal. In order to improve the surface contact between the bearing element (25) and the inner bearing surface (27) in the roller cutter (12), and in order to remove impurities from the cooperating bearing surfaces a longitudinal groove (30) is provided in the bearing element (25). The fluid primarily supplied for flushing the groove (30) is secondarily used to cool the bearing element (25).

Abstract: A percussion drill bit comprises a bit body including a shaft having a conical mounting portion to be mated with a conical mounting portion of a drill rod by means of substantially longitudinal friction forces. An annular row of circumferentially spaced button inserts extend from a front face of the body. A central button insert is disposed centrally of the other inserts and extends axially from the front face of the body beyond the other inserts to define a pilot insert. The outer inserts are inclined at an angle relative to the longitudinal axis of the body. A centrally located flushing channel is provided in the drill rod.

Abstract: A tool mounting for a planing machine in which the cutting tools are exposed to high tangential forces. The tool is held on a rotary drum by a wedging action so as to be more readily replaced. The tool may comprise separate adapter and cutter bit components, or in the form of a one-piece member. The tool adapter includes a projection extending from an end opposite from the cutting tool. The projection includes a first contact surface and the mounting includes a second contact surface located outwardly from the first contact surface which first and second contact surfaces converge toward one another. In this way, the first and second contact surfaces cooperate with corresponding surfaces on the cutting head to wedgingly secure the adapter thereto.

Abstract: An improvement in a cemented hard metal is disclosed. A molybdenum-tungsten-carbonitride is disclosed having the structure of tungsten carbide wherein the molybdenum and/or tungsten are at least partly substituted for by a metal selected from the group consisting of Cr, Nb, Ta, V, Re and mixtures thereof. The carbonitride may be mixed with a binder metal and sintered in a conventional manner to form a dense, substantially pore-free material.

Abstract: In a sealing assembly of the type in which a pair of sealing elements contain mutually engaging sealing surfaces. The sealing surfaces are formed by the faces of a plurality of rods which are annularly arranged so as to present a continuous sealing surface. The rods are formed of hard material such as cemented carbide.

Abstract: A rotary roller bit comprising at least one rotatably carried roller cutter (12) and provided with sealing means (21) for preventing impurities from entering into the bearing system (14, 15, 16,) of the roller cutter. For purposes of preventing axial and wobbling movements of the roller cutter (12) relative to the bit head from creating high contact pressure at the contact surface between the sealing means (21) and the surface against which same seals the sealing means (21) is provided with an elastically yieldable tongue (25) which extends radially relative to the rotational axis of the roller cutter (12).

Abstract: A rock drill for percussion drilling comprising a central button insert and a row of outer button inserts. The central button insert extends beyond the outer inserts. For purposes of increasing the drilling rate and the life of the rock drill the ratios of respectively this extent (X) to the diameter (D) of the hole; X:D, and the transverse distance (Y) between the central insert and one of the outer inserts and the diameter (D); Y:D, shall be within predetermined limits.

Abstract: A rock drill bit comprises a steel body including a front peripheral surface having a plurality of holes. Each hole includes a steel cylindrical wall portion, a steel bottom wall portion, and a radially enlarged steel transition wall portion extending between a longitudinally inner end of the cylindrical wall portion and a radially outward end of the bottom wall portion. A plurality of hard metal inserts are mounted in the holes. Each insert includes: a cylindrical surface portion directly abutting against the cylindrical wall portion of said hole and extending longitudinally inwardly at least as far as the longitudinally inner end of the cylindrical wall portion of the hole. The transition wall portion of the hole extends from the longitudinally inner end of said cylindrical wall portion of said hole so as to contain no abrupt concave corners which cause localized stress concentrations in the wall of the hole and subsequent fatigue failure therein.

Abstract: A device for lubricating rotary drill bits of the type comprising a roller cutter (14) which is rotatably carried by means of a bearing system (15, 16, 17, 18). Fluid is supplied to the bearing system for cooling thereof through a cooling passage (31, 32, 33; 51, 61), and a lubricant is delivered to the cooling passage from a lubricant reservoir (36; 46) through a lubricating passage (40; 54). For purposes of controlling the supply of lubricant the outlet of the lubricating passage into the cooling passage is arranged axially behind the inlet of the lubricating passage in the lubricant reservoir.

Abstract: An improved process for the production of coated cemented carbide products is disclosed. A cemented carbide substrate is treated to form a metal carbide, nitride or carbonitride coating. During the last part of this treatment or subsequent thereto, a sulfur-and/or nitrogen-containing gas is added to the atmosphere to form a sulfide-and/or nitride - containing layer on the coating. Thereafter, a wear-resistant oxide (e.g., aluminum oxide) coating is applied to form the improved coated cemented carbide product.

Abstract: A bore head for reaming a pre-drilled hole in raise boring or for similar earth cutting operations comprising at least two sets of roller cutters. The roller cutters in the same set of cutters have the same number of rows of cutting means. The roller cutters are mounted in pairs on each side of the rotational axis of the bore head. During rotation of the bore head the cutting means move along concentric circles. In order to change the distance between two consecutive circles a roller cutter in one of the pairs of cutters is replaced by a roller cutter of the other set of cutters.

Abstract: A rotary drill bit comprising at least one rotatably carried roller cutter (17) and provided with passages (26,27,28) for supplying cooling fluid to the bearing system (11-15) of the roller cutter. For purposes of preventing the heat generated at an annular surface (31) transmitting axial forces from causing rapid bearing wear a recess (32) is provided in the annular surface (31). The recess (32) communicates with the passages (26,27,28) and extends entirely around the bearing shaft (16) for allowing circulation of cooling fluid therearound.