Abstract: A retainer device (10) is provided for retaining a drill bit (12) within a percussive drill assembly casing (2). The retainer device (10) includes a generally annular body (16) having a central axis and an inner circumferential shoulder portion (18) disposable within the casing (2) such that the body axis (17) is substantially collinear with a casing axis (2a). The shoulder (17) is deflectable between a first position (P1), where the shoulder (18) is contactable with the bit head (14) to retain the bit (12) within the retainer body (16), and a second position (P2). The second Position (P2) is spaced radially outwardly from the first position such that the bit head (14) is displaceable through the body (16) in a direction along the casing axis (2a). Also, the retainer device (10) includes a spacer (24) that locates the retainer body (16) at a desired axial position within the casing (2) and a centralizer (26) that centers the body (16) about the casing axis (2a).

Abstract: An improved bidirectional hydraulic jar. The jar comprises a two-ring valve assembly supported preferably on the inner mandrel for reciprocal movement inside a fluid chamber. The chamber comprises two larger portions joined by a narrowed restrictor portion. The valve obstructs passage of fluid through the restrictor portion except for a bleed passage, which comprises an adjustable metering space between the two valve rings. The jarring force can be adjusted by varying the size of the metering space, which is done simply by axially repositioning one of the valve rings. All impact surfaces are enclosed in the housing to prevent downhole debris from dampening the blows. The shoulder on the exposed end of the mandrel is champfered to prevent build-up of debris and to facilitate removal of the tool from the well. This jar can be re-cocked easily, without firing in the reverse direction, for unidirectional jarring operations.

Abstract: The down hole jar tool is a tool used to apply jarring forces to objects that may be obstructing the path of a down hole, or above-ground operation that requires a repetitive jarring action to dislodge or remove such objects. The tool is used by providing a linear input to a mandrel portion that draws back against a compressible unit of predetermined resistance until a releasing means abruptly releases the mandrel portion. The mandrel portion then rapidly moves in the direction of the linear input until it encounters a stationary anvil, which produces the desired jarring action. This tool may also be combined with accelerators and/or valves, as well as other tools, to create a more substantial jarring impact.

Abstract: An apparatus and method for directional drilling utilizing a fluid hammer. The fluid hammer is coupled to a bent steering member which, in turn, is coupled to a drill string. The bent steering member includes means for rotating the fluid hammer independently of the bent steering member. The means for rotating may be a mud motor or a dual drive, pipe-in-pipe mechanism. The fluid hammer may be directed by rotating the drill string and bent steering member to point the fluid hammer in a desired direction. The bent steering member may include a sonde for monitoring its orientation. Fluid pressure capable of activating the fluid hammer is conveyed to the fluid hammer by means of the drill string.

Abstract: A downhole drilling method comprises producing pressure pulses in drilling fluid using measurement-while-drilling (MWD) apparatus (18) and allowing the pressure pulses to act upon a pressure responsive device (16) to create an impulse force on a portion of the drill string.

Abstract: Two working pistons (AK1, AK2) strike on the anvil (10) of a drill device or a rock breaking device. One working piston (AK1) is a solid piston, while the other (AK2) is an annular piston. Both working pistons can work at the same or substantially the same rate. In general, the percussion rate acting on the anvil (10) can be doubled with two working pistons. The working pistons can be controlled in common or independent from each other. In a synchronous mode with equal phase, the impact energy is multiplied; in an asynchronous mode or a mode with opposite phases, the percussion rate is increased.

Abstract: The invention concerns a reverse circulation rock drill having a backhead attached to a piston and cylinder assembly between the backhead and a drill bit assembly and around a sample tube with the outer walls of the sample tube and piston profiled to provide air paths for power and exhaust strokes of the piston, a O-ring seal being provided in the backhead as a check valve.

Abstract: The present invention generally provides a downhole tool with an improved means of transmitting data to and from the tool through the use of wired pipe capable of transmitting a signal and/or power between the surface of the well and any components in a drill string. In one aspect, a downhole tool includes a body, and a mandrel disposed in the body and movable in relation to the body. A conducive wire runs the length of the body and permits signals and/or power to be transmitted though the body as the tool changes its length.

Abstract: The invention concerns a down the hole drill hammer assembly providing a full piston area exposure to driving fluid pressure by the omission of the usual finger valve from the upper piston area and providing the piston with blind bores at each end and passages through the piston wall enabling predetermined communication between the blind bores for exhausting pressure fluid through the drill bit assembly. Fluid transfer passages are also provided in the inner wall of an outer wear sleeve of the drill hammer assembly.

Abstract: Disclosed is a device for directional drilling including a drill head mounted on a drill column. A driving device applies an axial driving force to the drill column. A delivery device supplies a wash medium to the drill head through a channel in the drill column. The device provides for increased removal of material and drilling through hard materials by by providing a housing on the drill head having a receptacle for an axially movable piston and a piston drive for producing strikes of the piston acting on the drill head. A connecting link permits an axial movement between the drill head and the drill column. A channel for the wash medium may be sealed at least with respect to the end faces of the piston.

Abstract: A drill head for an apparatus for horizontal directional drilling. The drill head includes a device for detecting angular orientation, a holder for the device for detecting angular orientation, the device for detecting angular orientation being disposed therein, a hammer driven by a liquid and a drill bit. The holder, the hammer and the drill bit are connected head to tail along a longitudinal axis of a drill string with the holder at a proximate end of the drill head and the drill bit at a distal end of the drill head.

Abstract: A down-the-hole percussive hammer for rock drilling includes a cylindrical casing and a drill bit disposed at a front end of the casing. The drill bit includes a forwardly facing cutting surface and a center longitudinal passage extending forwardly through a rearwardly facing rearwardmost end surface of the drill bit. The passage includes a rearwardly facing impact surface. A piston is mounted in the casing longitudinally behind the drill bit for reciprocation in a longitudinal direction. The piston includes a front portion sized to enter the center passage of the drill bit and strike the impact surface of the drill bit during each forward stroke of the piston. The impact surface of the drill bit is spaced forwardly from the rearwardmost end surface of the drill bit by a distance of at least ten percent of a total longitudinal length of the drill bit.

Abstract: Apparatus is provided for introducing a consistent series of small and localized rotary impacts to a PDC bit during drilling, to improve PDC drill bit performance. Rotary impact supplements the nominal torque supplied by the rotary drive thereby avoiding lockup and potentially damaging energy storage in the drill string following windup, should the bit slow or hang up when drilling in difficult formations. The apparatus comprises a rotary hammer which is rotated about a bit shaft's anvil, preferably by a drilling fluid driven turbine. As the hammer rotates, potential energy is built up. When the hammer and anvil connect, the energy is released into the bit shaft and thus into the bit, increases its instantaneous torque and allows it to more effectively cut through difficult formations.

Abstract: A vibratory impact tool for loosening downhole stuck objects in oil or gas wells, utilizing an internal piston spring which is repeatedly compressed by hydraulic pressure, and repeatedly released by lifting a dart valve from a valve seat on a flow-through piston. When the dart valve is lifted from the valve seat by a tripping spring, flow resumes through the piston, quickly lowering hydraulic pressure above the piston, allowing the piston spring to sharply drive the piston against the housing. The dart valve is then reseated on the valve seat, causing the piston to again be driven against the piston spring, rapidly repeating the process.

Abstract: A reversible impact-operated pneumatic boring tool for reversing the direction of operation of the tool is disclosed. The tool includes two fluid supply lines, a striker and a non-mechanically biased directional control sleeve. The primary fluid supply line provides pressurized fluid for striker reciprocation within the tool body to drive the tool through the soil. The secondary fluid supply line provides pressurized fluid to determine direction of operation of the tool. Pressurized fluid is supplied to a sealed chamber behind the directional control sleeve to drive the sleeve forward and operate the tool in a forward mode. The control sleeve is held forward solely by maintaining sufficient positive pressure of the fluid in the sealed chamber. Whereas, the depressurization of the chamber solely, will cause the sleeve to be moved to a rearward position thereby causing the tool to operate in the reverse mode.

Abstract: Three air hammers are housed and arranged in a hammer case, and have bits at their respective ends. Each of the air hammers can be activated independently. In a normal excavation, the earth is excavated by activating all the air hammers. When correcting an excavating direction, only an air hammer positioned in the correct direction is activated first so that the earth in the correct direction is excavated in a predetermined amount. Next, all the air hammers are activated to excavate the earth. Thereby, a leading hammer can direct the excavation toward the correct direction, and thus the excavating direction is corrected.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: A down-the-hole percussive hammer includes a cylindrical casing adapted to carry a drill bit, and a piston mounted in the casing for reciprocal movement to repeatedly strike the drill bit. A top sub is mounted at a rear portion of the casing, the top sub including a front face facing the piston. A feed tube is mounted to the top sub and extends forwardly along a center axis of the casing and defines an air-conducting passage. The piston includes an axial through-hole which slidably receives the feed tube. The front face and the feed tube together define a recess opening toward the piston. A removable volume-changer is insertable into the recess to vary a volume of a space in which the piston slides, and thus control a pressure at which the piston operates.

Abstract: A downhole drilling assembly (10) comprises a body (11) for mounting on a drillstring, the body defining a fluid conduit. A drilling fluid driven motor (12) is mounted in the body (11) and is coupled to a flow restricting device (14) axially movably mounted to the body (11). The device is coupled to a drill bit (16). In use, the flow restricting device (14) is driven by the motor (12) to vary the flow of drilling fluid through the body and produce a varying fluid pressure force to induce axial movement of the device (14) relative to the body (11), and thus provide a percussive or hammer drilling effect. The flow restricting device (14) may be coupled to the drill bit (16) by a mandrel (46) splined or otherwise coupled to the body. Alternatively, the flow restricting device (68) may be coupled to the drill bit (72) by a rotatable shaft (70), such that the motor (64) may also rotate the drill bit (72).

Abstract: An apparatus and method for directional drilling utilizing a fluid hammer. The fluid hammer is coupled to a bent steering member which, in turn, is coupled to a drill string. The bent steering member includes means for rotating the fluid hammer independently of the bent steering member. The means for rotating may be a mud motor or a dual drive, pipe-in-pipe mechanism. The fluid hammer may be directed by rotating the drill string and bent steering member to point the fluid hammer in a desired direction. The bent steering member may include a sonde for monitoring its orientation. Fluid pressure capable of activating the fluid hammer is conveyed to the fluid hammer by means of the drill string.

Abstract: The invention concerns a reverse circulation rock drill having a backhead attached to a piston and cylinder assembly between the backhead and a drill bit assembly and around a sample tube with the outer walls of the sample tube and piston profiled to provide air paths for power and exhaust strokes of the piston, a O-ring seal being provided in the backhead as a check valve.

Abstract: A rotary-percussion device for directional drilling in rock comprises a substantially cylindrical, rotatable body portion (15) housing a percussion hammer, and a frustroconical head (2) eccentrically mounted on the front of the body portion. The minimum diameter face (3) of the head is adjacent to the body portion. The axis (6) of the head is parallel to but offset from the axis (5) of the body. The front face (4) of the head is chisel-shaped and comprises at least one oblique plane (11) sloping forwardly in the same direction as the offset of the head axis relative to the body axis.

Abstract: A down hole hammer comprising a cylindrical casing defining a piston chamber between a top sub at one end and a drill bit support at the other end, a piston within the piston chamber for reciprocation between the one and other end, the piston having a central portion which is sealingly engaged with the internal wall of the casing, one end portion of the piston being intended to impact on the drill bit with movement to an impact position at which position the one end portion sealingly defines a first space at the one end of the piston chamber, the internal wall of the casing adjacent the top sub having two sets of axially spaced fluid ports, the piston adapted to cooperate with a first set of the fluid ports to admit fluid into the first space when the piston is in the impact position and cause movement of the piston to a raised position where the piston is in spaced relation from the drill bit support, the piston adapted to cooperate with a second set of said set of fluid ports to admit fluid into a second sp

Abstract: A downhole drilling method comprises producing pressure pulses in drilling fluid using measurement-while-drilling (MWD) apparatus (18) and allowing the pressure pulses to act upon a pressure responsive device (16) to create an impulse force on a portion of the drill string.

Abstract: A drill head for an apparatus for directional boring includes a bit having a cutting portion for use in steering, such as a gage tower mounted with carbide studs, suitable for cutting both hard and soft rock, a holder for a device for detecting angular orientation of the bit, and a pneumatic hammer connected head to tail with the bit at the front end. The valve in the hammer initiates reciprocation of the hammer in response to rearward movement of the bit, such as in response to a pushing force exerted by the drill string. The drill string components are preferably keyed to one another so that the orientation of the cutting portion of the bit used for steering is automatically matched to the position of the sonde. The sonde may project laterally so that its mass centroid is on the opposite side of the cutting portion of the bit used for steering to provide better cutting action. Such a drill head is suited for drilling in soil, soft rock and hard rock conditions.

Abstract: A hammer device has a machine housing (1) with a hammer piston (2) movable to-and-fro. The to-and-fro movement of the hammer piston is controlled by a valve body (6) movable to-and-fro in the machine housing. The valve body, via a channel (7), alternatively connects a drive surface (5) on the hammer piston to a pressure source (8) and to low pressure (9). In order to expedite the actuation of the hammer piston at its rear dead center, the machine housing has a room (10) which is separated from the channel (7) by the hammer piston at the same time that the valve body (6) maintains the pressure from the pressure source (8) on the rear end surface (5) of the hammer piston.

Abstract: In a ram drilling tool for producing bores in the ground and having a percussion piston which is moved to and fro in a casing, a control sleeve is guided such that it can be displaced on a control pipe projecting into a percussion-piston chamber and whose axial position determines the direction of movement of the tool. In order to permit the movement to be reversed, a control chamber connected to a control-air line is arranged between the control pipe and the control sleeve, and its front end terminates flush with a collar at the front end of the control pipe.

Abstract: A method of creating an electric signal that describes the motion of a down-hole, fluid-driven percussive tool is disclosed. The signal is obtained by attaching an electromagnetic transducer to the percussive tool, the member impacted by it, or the drill string. The rebound characteristics of the tool yield a measurement of the physical characteristics of the subterranean formation being penetrated. The tool's position over time is useful for diagnosing and regulating the operation of the tool. The transducer can also be configured to generate a signal large enough to be used as a power source.

Abstract: A hydraulic percussion drill includes a piston hammer disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve disposed around the piston hammer. The drill includes a percussion bit configured to have a face portion disposed at an acute angle with respect to a plane normal to the bit and the drill central axis. Cooperating spiral splines on the bit and a bit chuck provide for directional drilling using a method which includes causing the bit to receive impact blows without rotating the cylinder housing to initiate a deviated drillhole.

Abstract: The invention concerns a down the hole drill hammer assembly providing a full piston area exposure to driving fluid pressure by the omission of the usual finger valve from the upper piston area and providing the piston with blind bores at each end and passages through the piston wall enabling predetermined communication between the blind bores for exhausting pressure fluid through the drill bit assembly. Fluid transfer passages are also provided in the inner wall of an outer wear sleeve of the drill hammer assembly.

Abstract: A drill head for an apparatus for directional boring includes a bit having a cutting portion for use in steering, such as a gage tower mounted with carbide studs, suitable for cutting both hard and soft rock, a holder for a device for detecting angular orientation of the bit, and a pneumatic hammer connected head to tail with the bit at the front end. The valve in the hammer initiates reciprocation of the hammer in response to rearward movement of the bit, such as in response to a pushing force exerted by the drill string. The drill string components are preferably keyed to one another so that the orientation of the cutting portion of the bit used for steering is automatically matched to the position of the sonde. The sonde may project laterally so that its mass centroid is on the opposite side of the cutting portion of the bit used for steering to provide better cutting action. Such a drill head is suited for drilling in soil, soft rock and hard rock conditions.

Abstract: A hydraulic reciprocating piston hammer percussion drill includes an elongated piston hammer having opposed reduced diameter shank portions and disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve which is disposed in sleeved relationship around the piston hammer between a piston portion of the piston hammer and an impact blow receiving bit. The tubular sleeve valve is provided with ports which communicate with high pressure and fluid exhaust ports in the piston hammer to effect reciprocation of the sleeve valve and of the piston hammer to deliver repeated impact blows to the bit.

Abstract: A pneumatic impact damping device for a drill column comprises a first connection member for connection with the rear part of a drill column and a second connection member for connection with the front part of the drill column. Both connection members define a pneumatic cylinder chamber through which a bushing extends. The bushing has a passage moving Into and closed by a seal when an axial thrust force is exerted on the drill column. Thus, pressurized air is trapped and compressed in the cylinder chamber. In this manner, impacts applied to the front connection member by a deep-hole hammer drill are damped and prevented from acting on the rear part of the drill rod.

Abstract: Various jars are provided for delivering axial blows to a well string. In one aspect, a jar is provided that includes a mandrel and a housing telescopically positioned about the mandrel. A piston is positioned between the mandrel and the housing and closes a substantially sealed chamber in the housing. The piston has a first flow passage and a second flow passage which enable the selective flow of a fluid into and out of the substantially sealed chamber. A collet is positioned in the housing for selectively engaging the mandrel. A sleeve is positioned around and axially moveable relative to the collet. The sleeve has a reduced inner diameter portion at which the collet selectively expands radially to disengage the mandrel. Axial movement of the mandrel engages the collet, which in turn, moves the piston and pressurizes the chamber. When the reduced diameter portion of the sleeve is reached, the collet releases the mandrel, enabling the mandrel to impact an anvil surface of the housing.

Abstract: A segmented ring mounting (5) for retaining cylindrical components (2, 3) one within the other in a fluid-operated percussion drill tool, such as a downhole rock drill. The ring mounting also has application to other interengaging cylindrical components which are subject to heavy wear or pressure loading, such as compressors, pumps, borehole tools, casings and drillpipe mountings. The retaining ring (5) seats a smaller diameter cylindrical component (3) within a larger diameter cylindrical component (2), wherein one of the components is formed with a groove (12) or shoulder for seating the retaining ring in use, the ring being capable of radial compression and expansion so as to expand radially into the seating groove or shoulder for retaining the components one within the other in use.

Abstract: A check valve system is for a fluid-actuated percussive drill assembly including a casing, a backhead connected with and extending into the casing, and a fluid distributor disposed within the casing. The backhead has a central axis, a supply passage extending along the axis, and an outer surface section extending circumferentially about the axis and disposed within the casing. The check valve system includes a port extending between the outer circumferential surface section of the backhead and the supply passage. Preferably, several ports are spaced circumferentially about the backhead outer surface. An annular check valve is disposed about the outer circumferential surface section of the backhead and is configured to alternately permit fluid flow through the backhead port and substantially seal the backhead port.

Abstract: In an air actuated down-the-hole hammer for rock drilling, a piston reciprocates within a casing to impact against a rear anvil surface of a drill bit. Upon making such impact, some fluid disposed between the impact surface and the anvil surface is forced radially inwardly toward a foot valve which fluidly inner connects central passages extending through the piston and the drill bit. In order to minimize the wear of the foot valve imposed by such forced fluid, either the piston or the drill bit includes a projection extending around a radially inner peripheral edge thereof for deflecting the forced fluid in a direction having an axial component to minimize an impact force of the fluid against the foot valve.

Abstract: A downhole jar apparatus for use in oil and gas wells provides an improved construction that features a movable piston that imparts upward blows to the tool body during use. The apparatus includes an elongated tool body having upper and lower end portions and a longitudinal flow bore for enabling fluid to pass from the upper end of the tool body to the lower end portion thereof. A pair of pistons are slideably mounted within the tool body including an upper piston having a seat and a lower piston having a seat. A ball valving member is used to seal the upper piston, that ball valving member being pumped down through a work string such as a coiled tubing unit in order to reach the seat of the upper piston. A second valving member in the form of an elongated dart is disposed in between the two pistons. A trip mechanism separates the second valving member from the lower piston when a predetermined hydrostatic pressure value is overcome.

Abstract: Drilling device, of the type possessing a drilling unit of which the tool is driven to rotate from a hydraulic motor associated with an advancing device enabling a bearing force of the drilling unit on the ground to be created, the various actuating members being driven from at least one hydraulic pump via a set of hydraulic distributors and a set of tubes, such as hoses, the two feed tubes of the advancing device of the drilling system being equipped with a switch for reversing the direction of circulation of the fluid in the advancing device.

Abstract: A check valve system is for a fluid-actuated percussive drill assembly including a casing, a backhead connected with and extending into the casing, and a fluid distributor disposed within the casing. The backhead has a central axis, a supply passage extending along the axis, and an outer surface section extending circumferentially about the axis and disposed within the casing. The check valve system includes a port extending between the outer circumferential surface section of the backhead and the supply passage. Preferably, several ports are spaced circumferentially about the backhead outer surface. An annular check valve is disposed about the outer circumferential surface section of the backhead and is configured to alternately permit fluid flow through the backhead port and substantially seal the backhead port.

Abstract: A hydraulic impact tool for use in a well, such as an oil or gas well, comprising a movable hammer which is arranged to prestress a spring by means of a hydraulic piston (16) provided with a through channel (20), and in which a movable sealing body (22, 45) is arranged to enable closing of the channel (43), so that hydraulic force from fluid under pressure applied to the impact tool, may displace the piston (16) and the hammer and prestress the spring, and in which the sealing body (22) is arranged to follow the piston (16) into an end position for so to open the channel (20) for throughput, so that the hydraulic force acting on the piston (16, 41) ceases, and the prestressed spring is released and drives the hammer to strike, at the same time as the piston (16, 41) returns to initial piston, whereafter the process is repeated. The sealing body (22) is arranged to close said channel (20) when the sealing body is subjected to a predetemined frictional force from fluid flowing through the impact tool.

Abstract: A system for drilling a horizontal bore through frangible material includes a barrel mechanism containing a automatically reciprocating piston mechanism for automatically delivering hammering blows to a bit for chipping away the frangible material, a fluid distributor for directing fluid to and exhausting pressurized fluid from the piston mechanism without exposing the wall of the bore being created to fluid pressure greater than ambient atmospheric pressure, a spline/flute arrangement for causing the bit to rotate with the barrel mechanism, a motor and swivel mounted on a driven platform mounted on a supporting frame for urging the bit against the frangible material and for supplying the pressurized fluid, a pushing mechanism for non-rotatingly and simultaneously installing casing joints as various components of the system is rotatingly drilling the bore, an augering arrangement for, in conjunction with the casing joints, removing the drilling debris, and drill/auger stem sections for extending the drilling

Abstract: A hydraulic reciprocating piston hammer percussion drill includes an elongated piston hammer having opposed reduced diameter shank portions and disposed in a cylinder for reciprocating movement in response to pressure fluid acting continuously on one transverse face of the piston hammer and in response to valving of pressure fluid alternately to an opposed piston face of the piston hammer by a tubular sleeve valve which is disposed in sleeved relationship around the piston hammer between a piston portion of the piston hammer and an impact blow receiving bit. The tubular sleeve valve is provided with ports which communicate with high pressure and fluid exhaust ports in the piston hammer to effect reciprocation of the sleeve valve and of the piston hammer to deliver repeated impact blows to the bit.

Abstract: A coupling piece for use in drilling has a first connection (2) for connecting to an upper rotary percussion device (3), and a second connection (4) for connecting to a drill tube string (5) provided with an annular drill bit (23). The coupling piece has a first chamber (11) and a second chamber (12) separated by a piston. The pressure in the first chamber (11) is used to supply a lower percussion device (8) connected to a third connection (6) associated with the coupling piece with driving medium and for displacing the lower percussion device (8) towards the ground (15). The pressure in the second chamber (12) is used to decrease the force between the lower percussion device (8) and the ground (15) when further drill string elements are added to a drill string (7) of which the lower percussion device (8) forms a part.

Abstract: A sealing and venting system including an improved piston is for a drill assembly. The drill assembly includes a fluid distributor within the casing with an elongated guide portion having an outer surface, a passage through the guide portion and a port between the outer surface and the passage. The improved piston is slidable within the casing and has an interior surface disposeable about the outer surface of the guide portion. A valve chamber, an exhaust chamber and a drive chamber are defined within the casing. The system includes a sealing surface disposed within the piston passage and slidably engageable with the outer surface of the guide portion to provide a seal between the piston and the distributor. The sealing surface prevents fluid communication between the drive chamber and the exhaust chamber when the sealing surface engages the outer surface of the guide portion, and is provided by an interior surface section of the piston body or by a separate ring seal.

Abstract: In an air actuated down-the-hole hammer for rock drilling, a piston reciprocates within a casing to impact against a rear anvil surface of a drill bit. A foot valve extends axially between the piston and the drill bit. The anvil surface is inclined downwardly in a radially outward direction to cause liquid on the anvil surface to be discharged in a direction away from the foot valve, to prevent damage to the foot valve which could occur if piston impacts were able to create high-speed liquid streams contacting the foot valve.

Abstract: In order to consolidate soil, a hole is drilled therein by advancing downwardly through the soil a rotary percussive drill bit disposed at the end of a drill string. Water is pressurized at the ground surface and is conducted to actuate a hydraulically driven down-the-hole hammer disposed above the drill bit. While vertically retracting and rotating the drill string, grout, which is pressurized at the ground surface, is conducted downwardly through the drill string and ejected laterally outwardly through a lateral opening in the drill string to produce a console of mixed soil and grout surrounding the hole. The water and grout are pressurized in respective chambers of a pump.

Abstract: A device for drilling a bore hole in the ground comprised of a rotary drive head and a hollow Connecting Rod Assembly on which the rotary drive head acts and which can be lowered into the hole in the ground through the rotary drive head. A tool head with several Drilling Hammers that work downwards and that are operated with a fluid driving medium are provided on the lower end of the Connecting Rod Assembly. In the case of an initial design form, a Rotary Connecting Head is located in the upper area of the Connecting Rod Assembly; a fluid driving medium under high pressure can be supplied to the upper end of the Connecting Rod Assembly through the rotary connecting head, and the rotary connecting head has a transition chamber in its Housing, sealed in the axial direction towards both sides and connected to an external Supply Line for the fluid operating medium.

Abstract: An impact driven oil and gas well tool for use with an elongated tubular string having a central flow conveying bore is provided for channeling pressurized fluid to the tool body. The apparatus further includes an elongated longitudinally extending tool body having a connecting end portion at its upper end for connecting the tool body to the pipe string. A fluid chamber in the tool body is provided that is in fluid communication with the pipe string bore. A stem is reciprocally movable within the tool body in a telescoping fashion. The stem includes a lower end portion for carrying a working member such as a drill. A pressure responsive valve is provided for controlling relative movement of the stem and the tool body. An anti-chatter annular sleeve is positioned in the fluid chamber and about the valve member. A spring extends between the sleeve and the valve member for holding the valve member off the seat until a predetermined flow rate through the tool body is reached.

Abstract: An air percussion hammer drill is disclosed for operation in an earthen formation. The air compression hammer mechanism comprises a piston that reciprocates while simultaneously rotating within its housing. A hammer drill bit slidably keyed to the bottom of the piston transfers the impact energy to the formation and rotates during operation independent of an attached drill string.