Abstract: A drill bit for percussive drilling includes a front surface in which cutting inserts are mounted. A recess is formed in the front surface, and a fluid channel extends through the drill bit for supplying flushing fluid to the recess. The recess is completely bordered by an endless land. Some of the cutting inserts are mounted in the land. Others of the cutting inserts are mounted in the recess in order to be cooled and flushed by a cushion of flushing fluid created in the recess.

Abstract: An improved hammer tool (20) for a boom mountable power hammer (14) for use in demolishing a work surface (12) of concrete and the like. The hammer tool (20) includes an elongated cylindrical body (22) having a first end (24) and a second end (26). The first end, (24) has a shank (28) of a size and shape to be received into the commercial power hammer (14). A hammer head (30) includes a top (32) and a bottom (34). The top (32) connects the hammer head (30) to the second end (26) at a transition section (38). The bottom (34) includes a convex shaped radial striking face (40), which is a portion of a sphere having a center (54) within a portion of the body. In use, the shank (28) and a portion of the body (51) containing center (54) is received and supported within the power hammer (14). The hammer head (30) is raised and lowered to make striking contact with the work surface (12) in a number sufficient to demolish the work surface (12).

Abstract: A percussion tool includes a housing part having a frontal end provided with an opening; a tool bit guide supported in alignment with the opening; and a tool bit slidably supported in the tool bit guide and projecting from the housing part through the opening. The tool bit is arranged for a reciprocating motion parallel to the longitudinal tool bit axis and transverse excursions substantially perpendicular to the tool bit axis. A transverse guide is attached to the housing part and displaceably receives an outer seal composed of a transverse slide. The transverse slide has an aperture through which the tool bit passes. The transverse slide and the tool bit are arranged such that the transverse slide and the tool bit move as a unit during the transverse excursions of the tool bit. There is further provided an inner seal disposed in the housing part between the transverse slide and the tool bit guide externally thereof.

Abstract: A drill bit is fictionally received over a drill rod via complementary generally frusto-conical male formation and socket. The socket has an inwardly protruding face at an angle with the longitudinal axis of the drill rod. The male formation on the drill rod has a depression in the form of an area where the convexity of the frusto-conical portion has been flattened at an angle so as to form a rocking formation at a selective location relative to the opposite ends of the male formation and the socket. A clearance space diverges away from the rocking formation toward a selective ends of the male formation and the socket. The frusto-conical male formation and the socket are a-circular and form positive driving engagement between the drill rod and the drill bit. An impact at the point of maximum clearance causes rocking about the rocking formation to break static friction and to facilitate release of the drill bit from the drill rod.

Abstract: A bit retention device for a bit and chuck assembly of a down-the-hole, percussive drill, for retaining a head section of a bit should the head section separate from a shank of the bit includes a chuck adapted for threadable connection to a drill casing, a drill bit, a bit retaining shoulder in the the assembly; a wear collar concentric about the chuck and bit and a flexible retaining member removably connected to the assembly, the retaining member extending radially between the wear collar and bit a sufficient distance to contact the retaining shoulder should the bit drop axially downwardly.

Abstract: A self-propelled percussion boring tool apparatus (10) and method for incrementally boring a generally vertical hole (12) to substantial depths. The boring tool (10) includes a torpedo-shaped elongated cylindrical casing (13) having a trailing pipe (22) coupled to and extending away from the back end (14) of the casing (13). In another instance, the boring tool (10) includes a trailing pipe (34) extending away from the back end (14) of the casing (13), and formed to be retained in the hole (12) after removal of the boring tool (10). In either arrangement, the present invention facilitates recovery of the boring tool (10) from bored vertical holes (12) of substantial depth.

Abstract: The present invention is a self-propelled hammer-bit assembly for pneumatically drilling a borehole in the earth. It includes a hammer-bit member having an elongated main body with a hollow area therein and at least one blade located in the hollow area. The blade(s) is adapted to receive pressurized air to impart a rotation to the hammer-bit member which has a bit located at its distal end. The bit has at least one orifice to permit exit of pressurized air from the hollow area. For lateral stabilization with free rotation of the hammer-bit member, a bearing collar is connected to its elongated main body. There is also a distal barrel with the bearing collar connected thereto and the hammer-bit member located in the barrel collar. Finally, a reciprocation mechanism is located within the barrel and connected to the hammer-bit member to impart vertical reciprocation of the hammer-bit member in response to pressurized air. The invention also includes the hammer-bit member itself.

Abstract: A loose crown underreamer apparatus (10) for boring into earth and other materials includes a crown (28) loosely coupled to a bit shank (12). The loose coupling mechanism (34) employed in the present invention reduces the occurrence of friction welds occurring between crown (28) and bit shank (12). Coupling mechanism (34) employed in the present invention includes a plurality of deformable polyurethane retainer balls (36) disposed in shank sockets (38) and corresponding crown sockets (40). Coupling mechanism (34) employed in the present invention allows for crown (28) to be uncoupled and re-coupled to bit shank (12) at will.

Abstract: In a percussion drilling apparatus, an impact block assembly is provided for sequentially driving drill rods into a subterranean formation, the impact block assembly including an impact block member aligned with one or more rows of drill rods and a combustion operated piston is arranged above the impact block assembly for sequentially driving each of the impact members downwardly into engagement with the aligned drill rods.

Abstract: The present invention relates to a sacrificial transmission sleeve for a reverse circulation down hole hammer of the percussive type actuated by a fluid under pressure, including an outer sleeve, a drill bit retained in retaining means, the transmission sleeve comprising a body and an annular flange extending from the body towards the drill bit, wherein the transmission sleeve has an outer diameter greater than that of the outer sleeve and substantially the same as the drill bit.

Abstract: An axially extending cutter bit has a shank extending between a trailing end (2, 7) arranged to be inserted into a tool chuck and a leading or working end (5, 8) with the shank between the trailing end and leading end being divided into a first section proceeding from the trailing end and a second section proceeding from the first section to the leading end. The second section is stepped inwardly from the first section. As a result, the energy throughput in passing shock waves is improved and higher material removal rates by the leading or working end are achieved.

Abstract: A flexible metal dust boot, comprising a bellows, and a surrounding protective shroud capable of withstanding high temperatures. The boot and shroud are mounted on a support plate, which can be conveniently attached to the body of a reciprocatable hydraulic or pneumatic hammer. The boot and shroud extend from the bottom of the hammer body, in surrounding relationship to the tool. The support plate forms a seal against the bottom surface of the hammer body. The bellows is attached to the plate at one end, and to the tool, in fluid tight relationship, at the other end. An air fitting in the bellows structure facilitates connection to a pressurized air source to inhibit the entry of particulate matter as well as fluids in the hammer is submerged in use. During hammer operation, the bellows reciprocates with the tool. The shroud surrounds the bellows and extends the axial length of the bellows to shield the bellows from particulate matter generated during operation of the hammer.

Abstract: A percussion drill includes a reciprocating piston surrounded by a cylindrical casing. Disposed at opposite ends of the cylindrical casing are replaceable hollow cylindrical wear sleeves. The wear sleeves are mounted within recesses formed in the outer surface of the casing. Each wear sleeve has a thickness equal to the depth of its respective recess. A longitudinal inner end of each wear sleeve is spaced longitudinally from an end surface of the recess, and a flexible seal is situated between those opposing ends. The wear sleeves can be replaced after being worn by the abrasive environment encountered in the hole being drilled. The wear sleeves may be formed of a more wear resistant material than the casing.

Abstract: A retention system is disclosed for a hammer-percussion bit assembly which prevents the loss of the lower section of bit after a crack propagates through the shank (rotational drive) section of the bit. The system includes retainer which is mounted onto the drive sub of the assembly. The retainer is adapted to extend around the head section of the bit and functions to grab the severed bit head section upon lifting of the drill string while not interfering with the normal operation of the assembly.

Abstract: A low velocity, high mass ram is connected to the cutting tool. The cutting tool has an array of impact forward and side buttons or bars which form chip-forming spaces there between. The side buttons or bars advantageously cut a gage in the slot. A method of slot kerfing which cuts the kerf on an angle.

Abstract: A scabbler bit comprises a carrier having a body 30 with a lower face 31 formed to provide bores 32 for receipt of scabbler tips 44. The body 30 has a central bore 33 for passage of a fixing shank 34. The bore 33 is enlarged at the lower face 31 to form a recess 35 to receive the head 36 of the shank 34. The opposite face of the body 30 is formed with a counterbore 37 to receive the piston 38, the shank 34 being retained in the piston by a pin 39. Thus, axial loads on the scabbler bit are transmitted to the piston 38 via shoulder 40 of the carrier bearing on end face 41 of the piston 38, while any sideways of twisting load is resisted by the wall of the counterbore 37 bearing on the side face 42 of the piston 38.

Abstract: A metal punch is formed of a cylindrical body member having an outer cylindrical surface and a forward workpiece engaging end; an axial bore extends rearwardly from the forward end with the workpiece engaging portion of the being defined from front to rear by planar surfaces in first and second perpendicular planes, first and second transverse cylindrical surfaces and first and second annular arcuate surfaces. The planes intersect along a line passing through the axis, to define cutting edges. The transverse cylindrical surfaces are symmetrical to each other with respect to the axis as are the annular arcuate surfaces.

Abstract: A percussion drilling apparatus for drilling bore holes into subterranean formation in which a plurality of drill rods are arranged in concentric rows in a drill bit housing, each rod having an impact tooth at its lower ends and the rods arranged either to converge inwardly adjacent to the center of the housing or to diverge outwardly at progressively increased angles in each row toward the outermost row. The impact teeth are fired sequentially by concentric combustion chambers arranged above the drill rods and where the pattern and rate of firing can be controlled by cam operated intake and exhaust valves associated with the combustion chambers. The drill bit housing is arranged at the lower end of the drill string with an umbilical cord which carries all necessary cables and lines between the surface controls and the drill bit housing for the purpose of controlling combustion in each chamber and of carrying away the cuttings as the drilling operation proceeds.

Abstract: A replaceable bit for cable drill tool stems including a leading longitudinal cutting rib and first and second lagging, flattened reaming portions. The cutting rib diametrically extends between and bisects the reaming portions which partially extend about the bit's circumference and progressively taper upward from a wedged horizontal cutting edge. Inwardly flared channels mating with reliefs in the drill stem are defined by the inner bit surfaces on each side of the cutting edge. Beveled top edges converge to a flat welding surface mating with a prepared drill stem. A method of replacing a worn bit on a dril bit stem with such a replaceable bit is also disclosed.

Abstract: The present invention is a rock bit insert including a polycrystalline diamond surface on an insert body having a head portion made from a material with elasticity and thermal expansion properties advantageously tailored for use in three types of rock bits, as well as the three types of rock bits made with such inserts. The three types of bits are a roller cone rock bit adapted to be used with mud as the drilling fluid, a roller cone rock bit adapted to be used with air as the drilling fluid, and a percussion rock bit.

Abstract: A percussive tool, and a tool bit for the percussive tool for cutting the face of a deposit to be extracted. The tool bit is a circularly cylindrical columnar structure driven axially by the percussive tool. It is laterally unsupported and unobstructed for a substantial reference length. It has a circular cutting edge whose outer diameter increases as it extends axially away from its cutting end. Its ratio of wall thickness to outer diameter, and reference length to wall diameter, are such as to resist permanent lateral deformation and euler-type columnar collapse. When mounted, the bit is rotatable around its own central axis.

Abstract: A drill bit for use with a reciprocating device, wherein the bit is in the form of a rotatable corrugated frusto-conical roller, supported by a U-shaped member, attached to a mounting post. The corrugations are the cutting edges of the bit.

Abstract: The present invention relates to a seat protector device of the type which may be employed with drill rods for transmission of thrust from a driving member to a driven member. More specifically, the invention relates to an improved drill rod system for earth drilling where the rod also provides an axial passageway for a fluid to carry drill cuttings away from the cutting area. The seat protector device of the present invention may be detachably inserted between one or more drill rod sections and/or between one of the drill rods and the drill bit and/or between one of the drill rod members and the driving chuck for transmitting thrust load forces while simultaneously reducing damage and/or wear between the component parts.

Abstract: A rock drill in which the depth of the recessed groove for accommodating the cutting body is made greater than the axial brazing-in depth of the cutting body whereby a largely stress-free seating of the cutting body results. In particular, for rock drills for making break-throughs, this recessed groove extended in the radial direction into lobes of a drill head can be used for locating cutting bodies in the lobes.

Abstract: A drilling tool for percussion drilling machines is proposed which has an increased endurance strength or fatigue strength when used in percussion drilling machines having a high striking speed. For this purpose, the carbide cutting tip (11) is arranged transversely to the flute runout (12, 13) so that the effective moment of resistance area in the area of the groove root (22) of the recessed groove (14) is not weakened by flute runout surfaces.

Abstract: A percussion rock bit comprises a steel body having means for connection to a drill string at one end and having a plurality of inserts at the other end for crushing rock at the bottom of a hole being drilled. The inserts have a cemented tungsten carbide body partially embedded in the steel bit and at least two layers at the protruding drilling portion of the insert. The outermost layer contains polycrystalline diamond. The remaining layers adjacent the polycrystalline diamond layer are transition layers containing a composite of diamond crystals and precemented tungsten carbide, the composite having a higher diamond crystal content adjacent the polycrystalline diamond layer and a higher precemented tungsten carbide content adjacent the tungsten carbide layer.Another embodiment of rock bit has three cones with tungsten carbide inserts in the cutting structure of each cone. The gage row inserts have a layer of polycrystalline diamond on the converging portion protruding from the surface of the cone.

Abstract: A hammer drill has clamping jaws which are provided, in addition to clamping surfaces for radial clamping a cylindrical tool shaft, also with additional axially extending guiding surfaces for axially non-rotatably holding and guiding of the tool shaft, and the tool shaft is provided with guiding grooves associated with the clamping jaws.

Abstract: A joint device in extension drill equipment for percussive drilling is so constructed that, besides transmitting compressive pulses in the drill string in the direction towards the drill bit, it also by reflection transforms tensile pulses in the drill string into compressive pulses. Preferably, the joint device includes members that are axially movable relative to each other and provided with interacting surfaces, and an element connecting the members. Compressive pulses cause these surfaces to abut each other under pressure, while tensile pulses cause the surfaces to become separated. Also preferably, the joint device includes a structure for absorbing kinetic energy generated in the device by torsion pulses in the drill string.

Abstract: A drill is secured in percussion drilling machines and in tool holders of hammer drills by locking elements. The locking elements fit into axially extending grooves formed in the axially extending circumferential surface of the shank of the drill. Webs located intermediate the ends of the grooves divide the grooves into axially extending groove sections with the locking elements fitting into the groove sections. The outer surfaces of the webs are located in the circumferential surface of the shank and serve to support the jaws of the tool holder in the correct position.

Abstract: A driving head which can be used for pneumatic pile drivers and can serve as an attachment head for rods or pipes which are to be driven in pile drivers. The driving head has an essentially circular front end and a conically expanding surface over the periphery of which are uniformly distributed a plurality of longitudinal grooves which start from the front end. Also provided is at least one transversely extending section which extends around the surface in a circle. The longitudinal grooves have a V-shaped cross section, and the surface of the driving head is formed by a plurality of conical sections which are offset in the manner of steps via jumps in the diameter. The end faces formed between the individual conical sections are disposed at an angle in a range of from 45.degree. relative to 90.degree. to the longitudinal center line of the driving head.

Abstract: Sealing means for telescopically related elements, especially elements such as the bit shank and body of a fluid-powered free piston hammer drill, comprise a diametrically divided sealing ring dimensioned to run sealingly and circumferentially uninterruptedly on a cylindrical sealing surface on one of the elements (e.g. the bit shank of a hammer drill) and sealingly to engage the other of the elements (e.g. the drill body). The sealing ring may be constructed of any material suited to its duty. If it is to perform a retaining function by limiting relative motion of the elements it may be of steel or other hard and strong material and may if required have a flexible or elastomeric sealing element.

Abstract: This invention relates to a method of brazing a hard metal insert into a recess in the bit of a rock working tool and to a tool produced by the method. The method includes the steps of shaping both the underside of the insert and the base of the recess to a tapered point with an angle of taper of about 130.degree., placing the insert, which is a loose fit in the recess, so that the base of the bit fits complementally into the tapered base of the recess to centralize the insert in the recess and causing a moulten brazing medium to flow into the recess between its walls and those of the insert.

Abstract: The shaft of a drill steel for down-hole drills having a longitudinally grooved outside is detachably connected to a bore crown widened out towards the working surface and fitted with flush bores, cavities and hard metal inserts. The bore crown is larger in diameter than the drill steel shaft and is interchangeably secured to it. Form-locking companion parts may be axially and/or tangentially cushioned by elastic material, e.g. by resilient pads located under stress between the lower shaft end and an inner wear bit face. A central passage in said shaft is continued through a central resilient pad that can be made up of two integrally joined parts having different mechanical properties. Preferably, shaft and wear bit have matching disharmonic polygonal profiles. Fastening ring and stop means for the detachable yet secure connection of shaft and wear bit are preferred to use a thread of symmetrical, rounded thread-pitch turning in the same direction as the down-hole drill.

Abstract: A power tool includes manually operated selector means for alternately establishing rotary-hammer and hammer-only modes of operation for the associated drill bit. The attachment is in the form of an elongated member having a longitudinally extending blind bore for receiving the drill bit; retaining means are provided for releasably mounting the attachment on the drill bit. An annular shoulder defining the mouth of the blind bore is in abutting engagement with another annular shoulder, the latter being arranged to receive impact blows from the hammer mechanism of the power tool. In one embodiment, this second mentioned annular shoulder is constituted by a tappet forming part of the hammer mechanism. In another embodiment, this second mentioned annular shoulder is an integral part of the drill bit. Impact blows are transmitted to the attachment only through the area of engagement of the aforesaid annular shoulders.

Abstract: A well drilling bit of generally circular transverse cross-section and generally in the form of an elongated, generally cylindrical metal bit which tapers slightly outwardly toward its lower end with the lower end having a slight outward flare around the periphery thereof. A pair of diametrically opposed water courses in the form of longitudinal grooves extend from the lower end of the bit to a point adjacent the upper end thereof with the upper end of the bit having a screw threaded connection to the jar. The lower end of the bit is provided with a plurality of substantially parallel ridges and grooves in which the two center ridges are slightly higher than the others and the bottom end surface of the bit is slightly concave from edge to edge along the length of the ridges and valleys.

Abstract: When a pilot hole is pushed through the soil from one location to another prior to pulling an earth cutter through the pilot hole, it is often found that the pilot hole has deviated from a straight line. This deviation is usually at the maximum at the exit end of the pilot hole. The present device is a substantially rectangular cutter assembly having a pipe connection allowing it to be attached on the end or along the length of the pilot hole forming pipe. The offstanding cutter portion not only cuts a plug of soil as it is pulled through the soil in one direction, but compresses this plug slightly. When the device is moved in the opposite direction, projections or the like engage this compressed plug and facilitate the extrusion of the plug through the exit end of the pilot hole. The device is secured either to the end of the pilot hole forming assembly or adjacent thereto, at the exit end and is turned so that it is offset in the direction opposite to the direction of the deviation.

Abstract: The present invention relates to a sacrificial transmission sleeve for a reverse circulation down hole hammer of the percussive type actuated by a fluid under pressure, including an outer sleeve, a drill bit retained in retaining means, the transmission sleeve comprising a body and an annular flange extending from the body towards the drill bit, wherein the transmission sleeve has an outer diameter greater than that of the outer sleeve and substantially the same as the drill bit.