Abstract: An earth anchor apparatus adapted to be driven by a source of rotational driving force into unbroken soil includes a longitudinally extending hub having first and second axial ends. A recess is provided in one axial end of the hub by which the anchor may be driven, and a radially extending, load-bearing element is affixed to the hub between the axial ends. An earth engaging lead tip extends axially from the second end of the hub and includes a first cutting edge extending in a direction generally transverse to the longitudinal axis of the hub and arranged to cut into and break soil encountered thereby, a front surface extending between the hub and the first cutting edge, and a second cutting edge extending between the first cutting edge and the leading edge of the load bearing element. The second cutting edge is adapted to both cut soil and guide it from the first cutting edge toward the load-bearing element along the front surface so that as soil is cut it is moved away from the unbroken soil.

Abstract: A carbide-tipped drill bit and method for manufacture is presented which produces drill bits of consistent geometries in which the flutes are machine ground in one step, which eliminates the hand blending operation of the carbide insert as used in the prior art. As a result, carbide-tipped drill bits are manufactured having a single helix angle which is consistent from drill bit to drill bit.

Abstract: A steerable earth boring device comprises a compaction auger rotatably mounted to a housing at one end of the auger such that the compaction auger is substantially externally exposed. A steering tip is pivotably disposed at the other end of the compaction auger for providing steering control for the earth boring device. An internally housed steering mechanism is provided for pivoting the steering tip relative to the compaction auger while the auger is rotating. The steering mechanism includes a non-rotatable cam disposed within and pivotably connected to the housing and a follower rotatable with and pivotable relative to the compaction auger. The cam and follower contact at a bearing surface so that pivoting motion of the cam is transmitted to the rotatable follower. A control member is connected between the follower and the steering tip, extending through the compaction auger, to transmit pivoting of the follower to pivoting of the steering tip.

Abstract: An ice auger conversion kit is mounted to a conventional grass-timming apparatus that includes an engine mounted rearwardly of a drive shaft housing with a drive shaft mounted therethrough. The forward end of the drive shaft is of a square drive configuration and is received within a square bore of a rotatable boss coaxially mounted through an adapter head, wherein a forwardmost end of the adapter head includes an axially extending threaded second boss for mounting the ice auger cutting head. The adapter head includes a series of gears to effect a gear reduction therethrough to enhance torque and effect appropriate speed of the ice auger head in use.

Abstract: A drilling tool, in particular for use in axially striking drive machines for drilling in rock, concrete or the like, which drilling tool is designed from both a vibration point of view by varying the abrupt changes in cross-section and from a drilling point of view by optimising the transport of the drilling dust. In order to arrange, from a vibration point of view, the abrupt changes in cross section, caused by the flute webs, in asymmetrically arranged axial positions, the inclination of the conveying flute constantly changes its size within a lead. Furthermore, the radial, tangential and axial force vector which acts on the drilling dust constantly changes its size, the radial force vector also changing its direction. In this way, the drilling dust is subjected to a constantly changing acceleration.

Abstract: A rock drill bit having an elongated tubular body with a drilling head portion at one end and a trailing opposite end portion, the head end portion having attached hardened portions for engaging and drilling a work surface, at least one opening through the head end portion for drilling fluid to pass therethrough to the region of the drill face, at least one side of the bit having an axially extending cutout therealong forming an elongated passage with the surface of a bore being drilled through which the drilling fluid and drilling residue carried thereby can pass as it moves rearwardly along the drill bit away from the drill face, and transversely extending grooves formed in the portions of the body between the cutouts dividing the portions into a plurality of spaced outwardly extending body portions.

Abstract: A rock drill having a drilling head which, in an asymmetric arrangement relative to the main cutting tip, has at least one additional secondary cutting tip, the angle enclosed between the single cutting edge of the main cutting tip and the secondary cutting tip being formed as an acute angle.

Abstract: A method of rapid earth excavation without damaging buried pipe, cable or other underground objects utilizes drills and augers having soft cutting edges and/or control of the torque and weight of the boring apparatus. In one embodiment, the bit of a drill, or bottom end of an earth auger is equipped with inserts formed of soft polymeric material. Another embodiment of an earth auger apparatus has soft polymeric material on the leading cutting surface of the flight, or the auger flight may be formed of soft polymeric material. The flexibility and low abrasion of the polymeric material prevents damage to the object contacted. Another embodiment has a dual concentric auger with a small earth-auger rotatably mounted inside the shaft of a larger auger and driven independently such that each is capable of providing and maintaining a torque adequate to create a given hole diameter but sufficiently below that which would damage the object expected to be encountered.

Abstract: A drilling tool is proposed which is preferably suitable for making apertures in concrete work or masonry is fissured rock. To avoid damaging an interchangeable conveying helix (4), the connection between the conveying helix (4) and drilling head (3) is made as a frictional-resistance connection (FIG. 2).

Abstract: An auger for use in drilling into the earth under rotative movement in one direction of rotation, the auger having a cylindrical stem and a helical flight extending along the length of the stem, the helical flight being defined by adjacent segments of opposite flight orientation. The auger of the present invention enables the drilling of fast holes of any conventional size to any conventional depth required in overburden and bedrock. It reduces the tendency of bore hole wall collapse through the use of bore hole material to stabilize the hole and reduces the amounts of drilling muds needed.

Abstract: A rock drill for rotary and/or percussive stress, in particular for use in percussion or hammer drilling machines, is proposed, which by its geometrical design makes improved efficiency and simplified production possible. For this purpose, the feed spiral 5 is designed alternately with horizontal feed sections 8,8' with a 0.degree. pitch, and adjoining lead sections 9,9', the respective feed sections assuming an angle of rotation of 90.degree. on the drilling tool.

Abstract: An excavating tooth for use in connection with an earth drilling auger includes a main body portion terminating in a working end and a shank extending upwardly from the main body portion. A plurality of tungsten carbide inserts are embedded in the working end of the tooth and project outwardly therefrom. During drilling operations, the carbide inserts engage the earth and chisel away rock and other material which is subsequently conveyed to the surface by the fight structure of the auger. The inserts are inclined forwardly with respect to the plane of the shank to enable the inserts to withstand greater loads than before. In the preferred embodiment, the insert has a generally cylindrical proximal end embedded in the working end of the auger tooth and a distal end including forward and rearward inclined surfaces terminating in a transverse cutting edge.

Abstract: A hollow drill bit is formed of an axially extending tubularly-shaped support member (1) with cutter elements (2) inserted into the leading end (1a) of the support member. Each cutter member (2) has a radially outer surface (2a) and a radially inner surface (2b) with channels (2c, 2d) in each surface inclined relative to the axis of the support member (1). The channels (2c,2d) carry a flowable cooling agent to the leading end of the drill bit, and remove drillings produced by the bit from the leading end.

Abstract: A rotary gad for a ground drill includes an elongated front body having a front end and a rear end with front spiral blades being disposed on the outside of the front body. The front body has an elongated front axial passage, and a front core rod is disposed in the front axial passage. The front body is rotatable about the front core rod. The front core rod has a front end and a rear end. An elongated rear body has a similar construction and a pushing section is provided on a rear axial passage in the rear body. The pushing section has a front side and a rear side. A rear ball element is disposed between the rear side of the pushing section and the front end of a rear core rod, and a front ball element is disposed between the front side of the pushing section and the rear end of the front core rod. Coupling means couple the front and rear bodies to provide for rotation of the front and rear bodies in opposite directions about the front and rear core rods.

Abstract: The tool includes a shaft adapted at its upper end to receive a power source. Flighting extends partially along the shaft above a pair of radially directed elongate blades which project outwardly from the shaft a distance beyond the flighting edge. A modified form dispenses with the flighting.

Abstract: A rock drill is provided in which an optimum support of the carbide cutting tip or of a cross cutting edge is achieved by the drill head being made square or rectangular in cross-section. This results in an optimum strengthening of the cross-section against fracture in the slot root for the cutting tips. Moreover, catching of the drill in fissured rock and under extreme loads such as in reinforcement drill holes is avoided.

Abstract: A rock drill for rotary and percussive stressing exhibits equally good or improved transport characteristics of driling dust for a smaller transport groove as compared with prior rock drills. In order to achieve this, a main transport groove having longitudinal profiles is formed, with an interrupted secondary transport groove integrated in the main transport groove, the transport ribs of which exhibit a greater angle of twist than the angle of twist of the main transport groove.

Abstract: A drag type rotary bit (10) having a plurality of arcuate blades (24A-24E) each having a row of cutting elements (36A-36G) thereon. The cutting elements (36A-36G) are arranged on the arcuate blades (24A-24E) with around one-half of the length of the arcuate blades (24A-24B) being positioned adjacent the outer periphery (20) of the bit body (12) to provide a relatively long length mounting area or the cutting elements (36D-36G) at the gage (20). Deep grooves (26) are provided adjacent each of the blades (24A-24E) and provide a relatively large passage for the outwardly flow of drilling fluid and entrained cuttings.

Abstract: The earth auger is provided with a clearing blade near the top of the flight for clearing loose soil from about the mouth of the drilled hole. A second blade is provided at the distal end of the auger within the contour of the flight for cutting of fibrous roots and to loosen the soil to encourage plant root growth.

Abstract: A drag type rotary bit (10) having polycrystaline diamond compact (PDC) cutting elements arranged in a plurality of rows extending from the center of the bit body (12) to the outer peripheral surface (20) thereof. A fluid discharge nozzle (38A-38F) is provided for each row of cutting elements (36A-36G) and has a fluid discharge stream (62) directed downwardly against the bore hole bottom (66) and opposite the direction of rotation of the bit (10) ahead of the associated row of cutting elements (36A-36G) for flowing against the cutting faces (53) of the cutting elements (36A-36G) after impingement of the bore hole bottom (66).

Abstract: A drilling system is provided wherein a high pressure water jet is provided near the cutting tip of the auger, the water jet being directed upwardly into the slip stream of spoil to break up the spoil and reduce friction between the spoil and the auger.

Abstract: An earth anchor for embedding within the ground and incorporating a helical blade(s), having flattened side edges, intervened by rounded or arcuate corners, and connecting with its shank for securement with any driving apparatus useful for the power driving of such an earth anchor into the ground; while the shaped blade of this anchor incorporates a lineal cutting edge, and an arcuate cutting edge, that integrally blends into a segment of the lineal side edge of the blade, and which composite edges function as a compound cutting edge for driving of the earth anchor into the soil, and through the exertion of only a reduced force.

Abstract: A drill bit for drilling into earth formations comprising a plurality of sections having connection means to connect said sections to form a unitary drill bit; means in said plurality of sections for storing and delivering lubricants to the cutting cones; and wear bar segments on said plurality of sections to form continuous wear bars about the periphery of said unitary drill bit thus reducing the wear on said unitary drill bit.

Abstract: An interchangeable conveying spiral which can be removably, slidably mounted on a drill shaft for conveying drillings away from a drill head mounted on the end of the spiral. The spiral includes an elongated strip having at least first and second substantially orthogonal webs. The first web has a free, squared-off end. The strip is wound in a spiral with the free, squared-off end of one turn abuting the free, squared-off end of an adjoining turn of the spiral so that the first web forms a closed jacket tube which can be removably, slidably mounted on a drill shaft, and the second web serves exclusively as a transporting shoulder for conveying drillings.

Abstract: A method and apparatus for installing an in-ground support footing around subterranean and above-ground portions of an upstanding elongate object, such as a structural pole, post or the like, to enhance structural integrity thereof, includes providing a cylindrical casing of hollow construction having a cutting end concentrically positionable around a lower, above-ground region of the elongate object so that the cutting end engages the ground. A driver is then positionable about a circumferential portion of the casing means operable for engaging and rotating the casing means about its longitudinal axis while simultaneously imparting a downwardly-directed force against the upper edge of the casing means thereby to drive it in the ground to a predetermined depth.

Abstract: A flexible plug used in combination with a hollow stem auger and connected drill head which has a hollow housing. The plug includes a plurality of flexible shape-retaining arcuate projections extending towards the plug central axis.

Abstract: To the drill pipe connects a head comprising a cylinder-shaped portion and a cone-shaped point. Three spiral ribs are regularly distributed over the head. Each rib has a downwardly-extending rib portion standing on the point and having an outer side making an angle between 0.degree. and 5.degree. with the drill axis and an inner side making with the outer side of the point an angle which is smaller than 90.degree. increased by half the apex of the point, and has a outwardly-extending rib portion standing on the cylinder-shaped head portion and having a top side making an angle between 85.degree. and 95.degree. with the outer side of this head portion. The lowermost edge of the rib portion standing on the point merges into the outermost edge of the other rib portion. The apex of the point lies between 85.degree. and 95.degree..

Abstract: An improved spade type bit for use in drilling metal, masonry and the like. This bit has a replaceable transverse bar of hardened material in the tip thereof with symmetrical end surfaces sloping away from a central chisel point located on the axis of the bit. One of these surfaces is provided along its length with a groove extending from a cutting lip to the trailing edge, with the groove width and depth at the trailing edge having at least the same dimensions as at the cutting edge. Preferably the dimensions of the groove at the trailing edge are slightly greater than those at the cutting edge. The second of the surfaces has an outer portion with a reduced angle with respect to the axis of the bit as compared to the angle of the inner portion. This construction provides for the accurate drilling of holes in metal, masonry and the like and further accomplishes the drilling at increased penetration rates with the same or lower axial force applied to the bit.

Abstract: A cable following apparatus has a rotating annulus at the front portion of its main body where a cylindrical axial opening of the body passing over a cable first comes in contact with concentric neutral wires. The annulus, by rotating in the direction of the neutral wrapping wires, has the effect of wrapping down any wires that are broken. Further, a helical groove in the annulus extends forward beyond a static cutter plate providing a front surface of the main body. The end of the groove rotates slightly behind the static cutting surface of the plate. Wires that are broken and pulled away from the cable are picked up by the groove and carried to a position where they are cut off by the force of the side of the helical groove pressing them against the static cutter surface of the plate.

Abstract: A drilling bit having two helical withdrawal grooves which extend from the drilling head in the direction toward the insertion or chucking end. The withdrawal grooves have least slope in the vicinity of the drilling head. In the other regions, the withdrawal grooves have a different slope. As a result, no cross-sectional jumps disposed at uniform intervals are provided on the drilling bit, so that transverse oscillations cannot be reinforced by partially constantly or continuously reflected pulses. A considerable reduction in noise is achieved. Furthermore, the central portion of the drilling bit, which is critical during drilling, receives great rigidity.

Abstract: A rock drill is formed of an axially elongated member made up of a cutting bit at one end followed by a helically grooved shaft and then ending in a shank. At least a portion of the groove, viewed in the axial direction of the member, has a stepped bottom providing groove sections of different depths. The depth of the groove section from the surface of the shaft decreases in the direction toward the shank. The groove sections with stepped bottom commence at a certain axial length from the cutting bit.

Abstract: A boring tool which comprises a hollow boring tool body constructed by fitting a hollow boring head provided with cutting tips to the end of a hollow boring bar, and wherein an inner leftward twisted screw is formed on the inner peripheral wall of the hollow boring bar; and an outer rightward twisted screw is formed on the outer peripheral wall of the hollow boring bar; when the boring tool body is clockwise rotated, the cutting fluid is carried forward to the end of the boring tool by the inner leftward twisted screw, and the cutting fluid which has cooled and lubricated the cutting tips and chips entrained with said cutting fluid are forcefully discharged by the outer rightward twisted screw.

Abstract: An improved bit for use in drilling masonry and the like. This bit is of the type having a transverse bar of hardened material in the tip thereof with symmetrical end surfaces sloping away from a central chisel edge located on the axis of the bit. One of these surfaces is provided along its length with a groove extending from a cutting lip to the trailing edge, with the groove width and depth at the trailing edge having at least the same dimensions as at the cutting edge. Preferably the dimensions at the trailing edge are slightly greater than those at the cutting edge. The second of the surfaces has an outer portion with a reduced angle with respect to the axis of the bit as compared to the angle of the inner portion. This construction provides for the accurate drilling of holes in masonry and the like and further accomplishes the drilling at increased penetration rates with the same or lower axial force applied to the bit.

Abstract: A tool comprises two coaxial casings, a leading and a trailing ones, connected by a tubular element provided with ports for discharging a fixing material into a hole. The leading casing comprises a cylindrical portion, and frontal and rear conical tips provided with spiral tapered surfaces intended for consolidating soil. The trailing casing has a cylindrical portion of a greater diameter than that of the cylindrical portion of the leading casing. In the trailing casing there is provided an axial duct communicating with a cavity of the coupling element for supplying a fixing material. A method of forming holes having fixed walls includes formation of a pilot hole using the leading casing, and subsequent formation of a hole of a predetermined diameter using the trailing casing in the advancing sinking of a pilot hole.

Abstract: A method and apparatus for driving a hollow pile into the ground. By using a hollow rod having a short auger fixedly secured to a leading end portion thereof, excavated earth and sand are lifted to and around the upper portion of the auger where compressed air is spouted from nozzle orifices formed in the hollow rod thereby lifting the excavated earth and sand through the hollow pile and consequently discharging the same from the hollow pile. As earth and sand are discharged from the hollow pile, the pile is sunk or driven into the ground.

Abstract: A drill assembly or auger for forming a hole in a surface such as ice and having a readily extendible and retractable shank assembly. The shank assembly has first and second longitudinal shank members. One shank member is telescopically engagable in the other shank member and moveable between a first relatively retracted configuration of the shank assembly and a second relatively extended configuration of the shank assembly.First and second coupling members are located at longitudinally spaced intervals on said shank assembly for coupling the shank member having cutting means to the shank member with operating structure upon operation of the operating structure to rotate the shank assembly in a direction to form a hole selectively in the first and second positions respectively.The coupling members are releasable for telescopic movement of the shank members between positions by rotation of the shank member having the operating structure in a direction opposite that necessary to form a hole.

Abstract: A tool for the formation of holes without extracting the soil comprises a body having a cylindrical calibrating portion, coaxial portions with surfaces for the compaction of the soil and radii decreasing stepwise in the direction away from the calibrating portion, and terminating in an end piece. The body has also transition portions with surfaces for the compaction of the soil, forming a smooth transition from a coaxial portion with a larger radius to an adjacent coaxial portion with a smaller radius. The surface for the compaction of the soil of each coaxial portion is a conical surface having the configuration of a ribbon wound from the calibrating portion to the end piece and comprising the transition portions.

Abstract: A rock drill is formed of an axially elongated member made up of a cutting bit at one end followed by a helically grooved shaft and then ending in a shank. At least a portion of the groove, viewed in the axial direction of the member, has a stepped bottom providing groove sections of different depths. The depth of the groove sections from the surface of the shaft decreases in the direction toward the shank.

Abstract: A tool comprises a body having coaxial portions radially defined by soil compaction surfaces of step-down radii from the sizing portion to the tool tip. The soil-compaction surface of each portion is a cylindrical surface generated by a generatrix of a predetermined length extending parallel to the tool axis and bounded by two parallel helices of one and the same helix angle. These surfaces are successively conjugated by transition portions defined by a cylindrical surface whose generatrix is parallel to the tool axis and uniformly approaches the same axis to thereby form a smooth transition from the surface of the body portion of a greater radius to that of an adjacent body portion of a smaller radius. A method of forming a hole by the same tool is also described.

Abstract: A drilling head for use in mining operations comprises a cylindrical drum having an open rear end and defining an interior cavity, an exterior spiral arranged to forwardly advance mined particles, a nose spiral disposed in advance of the drum and arranged so as to rearwardly advance the mined particles, the exterior and nose spirals terminating generally at the front portion of the drum and together defining at least one recovery aperture through which the mined particles forwardly advanced by the exterior spiral and rearwardly advanced by the nose spiral can pass to the interior cavity, and an interior spiral coaxially disposed and rotatable in the interior cavity in a direction opposing the rotational direction of the drum.

Abstract: An eccentric mass rotor is employed to drive a column which may comprise a casing, piling, drill stem or the like into the earth. The rotation axis of this rotor is oriented such that when it is rotatably driven, a rotating force vector component is generated which lies in a plane substantially normal to the longitudinal axis of the bore hole. The rotating force vector causes a portion of the column formed by the drill stem, casing, piling or the like to precess or roll around the wall of the bore hole in a cycloidal manner in forceful engagement with the bore hole wall. Sloping ridges or spiral flanges are formed on a portion of the outer surface of the column, such that the rotary torque generated therein causes forceful engagement of these ridges or spiral flanges with the bore hole wall to thereby effect a screw action which operates to more effectively drive the column down into the earth or with reversal of the direction of torque to pull the column out of the earth.

Abstract: A drilling head for use in mining operations comprises a cylindrical drum having an open rear end and defining an interior cavity, an exterior spiral arranged to forwardly advance mined particles, a nose spiral disposed in advance of the drum and arranged so as to rearwardly advance the mined particles, the exterior and nose spirals terminating generally at the front portion of the drum and together defining at least one recovery aperture through which the mined particles forwardly advanced by the exterior spiral and rearwardly advanced by the nose spiral can pass to the interior cavity, and an interior spiral disposed so as to rearwardly advance the particles which pass through the recovery aperture. An assembly of counter rotating drilling heads is also disclosed.

Abstract: A rotary drill bit for use in subsurface formations includes fluid channels for the passage of drilling mud to remove cuttings. According to the invention to clear blockages there are only one or two unbranched channels for the passage of mud past the cutting elements and these are arranged in a spiral.

Abstract: An auger system is described having an upstanding axial stem with a pilot bit attached to the bottom of the stem. A downwardly spiraling flight structure affixed to the axial stem has a leading edge terminating in the vicinity of the pilot bit. Enhanced cutting operations are provided by way of a cutting tooth holder structure removably secured to the leading edge of the flight structure and extending from a position adjacent the stem above the pilot bit to a position proximate to the perimeter of the flight structure. The holder structure is provided with a plurality of spaced apart pockets for receiving shank portions of cutting teeth. Stresses applied to the cutting teeth during operations are distributed through the holder structure back to the flight structure by way of reinforcing webs which extend from a position proximate to each of the cutting tooth receiving pockets to a position for contact with the leading edge of the flight structure.

Abstract: A hole cleaning device which may be attached to the top of an auger or auger extension for rotation therewith includes two diametrically opposed blades arranged to resemble one flight of an auger, the outside diameter of the blades being suitably larger than the hole-digging auger itself. The two blades are secured to a mounting sleeve adapted to be secured to the upper end of the auger tube which supports the auger or to the top auger collar. To the top sides of the two blades are secured two elongated and radially extending deflecting elements, these being arcuately shaped and upstanding. As a hole is being drilled into the soil, the displaced soil is lifted and deposited onto the surface of the ground in an area around the hole. When the hole is drilled to full depth, the cleaning blades engage the soil build up, lifting and throwing it radially outwardly. For slow auger speeds, the loose soil is stacked in an annular pattern spaced from the hole.

Abstract: A vertically oriented screened hollow stem auger element for use in the simultaneous drilling and testing of wells so as to detect and monitor the existence of hazardous and toxic waste at subsurface levels. The screened hollow stem auger comprises an elongate cylindrical hollow body member having a longitudinal axial bore therethrough. The screened hollow stem auger is adapted at its opposite ends for selective lockable end to end engagement with solid wall hollow stem auger elements and other drilling components for use in the simultaneous drilling and testing of wells. The cylindrical wall of the hollow stem auger element is provided with a central screened portion in open communication with the bore thereof which permits the selective intake of ground fluids into the interior of the screened hollow stem auger element for selective conveyance through the interconnected solid wall hollow stem auger elements to the surface level for testing purposes.

Abstract: A drill bit (10) comprises a cast body (12) with full length wide overlapping integral spiral stabilizer lands (14) between intervening spiral grooves (16), integral short, strong, stubby spiral fingers (18) reinforced by additional web portions (12a) angularly spaced about a short core receiving bore (b) and the longitudinal axis of the body (21).An inclined core ejection passage (P) extends radially outwardly from a spherical inlet end thereof connected to the core receiving bore (b) and at which an inclined hard core cutter breaker inserted within a pocket is situated. The leading sides of the fingers have support surfaces (18a) and shoulders (18b) for supporting engagement with composite abrasive compact cutters comprised of a carbide backing (30a) bonded to the support surfaces (18a) and layers of bonded polycrystalline abrasive particles at opposite cutting sides (30b) inclined at a negative rake angle.

Abstract: A masonry drill and method for its manufacture are disclosed. The drill has an axially elongated body which is made from a die cast material and has one or more spiral grooves cast in its exterior surface substantially along its length. A hard insert is embedded in the leading end of the body. The insert is formed with sides having generally planar side portions, a top chisel edge, and a bottom edge. The insert preferably has means for interlocking with the body, the interlocking means preferably comprising a projection extending from the plane of each of the side portions. Each projection extends the greatest distance from the plane of the side portions near the bottom edge of the insert. The insert is held in place by casting the body around it so that the body substantially surrounds the projection, and especially entirely covers the portion of the projection nearest the chisel edge.

Abstract: An improved broach is disclosed incorporating, in the preferred and illustrated embodiment, an elongate tubular member constructed in the fashion of a drill collar having a raised external thread cut thereon in helical fashion, the thread having a top face. The thread tapers from the bottom to a maximum diameter at a very gradual rate. The top face includes a generally flat, exposed surface which is reinforced with particulate tungsten carbide. It additionally includes inserts of tungsten carbide at periodic locations as, for example, inserts located at ninety-degree intervals along the thread face. The inserts extend relatively deep and are constructed of a solid block of tungsten carbide in a supportive alloy. Another form has inserts made of cylindrical pellets.

Abstract: Disclosed herein is an aerator for use in providing cylindrical holes in a lawn or similar type surface so as to provide a nesting area for fertilizer and to allow the introduction of air beneath and along the root system of botanical life to be thus treated. The device comprises an elongate shaft from which emanates along the lower portion thereof a helical type of screw provided with shelf portions and a pointed extremity at the terminus of the shaft which is so constructed that the device not only cuts into the earth, but also carries the thus loosened dirt on the shelf portions so that when the device is removed from the hole a substantially cylindrical void is provided.