Abstract: A downhole vibration tool consisting of a body assembly installed in a work string, and a drop-in dart valve assembly. An open inner bore through the body assembly allows the performance of operations through the body assembly. To activate the vibration tool, the dart valve assembly is dropped into the work string and pumped downhole into engagement with the body assembly. Once the dart valve assembly is in place in the body assembly, continued pumping of fluid will cause the tool to begin to vibrate longitudinally. When the jarring operation is finished, the dart valve assembly can be released from the body assembly and retrieved, with a wireline or coiled tubing unit.

Abstract: The invention concerns a device for displacing a load (14) comprising a mobile support (12) adapted to support a load and exert on the load a force in a given direction, and device for mechanical balancing (10) interposed between the mobile support (12) and the load (14) so as to compensate the weight of the load and allow movements of slight amplitude of the load in a direction parallel to the load. The device is particularly useful for manoeuvring stakes, such as sheet piles and the like. The balancing device (10) can alternatively be integrated between the mobile support (12) and a vibration generator (46) to isolate the support from the vibrations generated by the vibration generator.

Abstract: Disclosed is a bit striking apparatus in an excavator capable of efficiently striking the entire area of the hammer bit under uniform pressure without exerting excessive load to the excavator so that the hammer bit may be free from damage owing to local concentration of striking force of the piston.

Abstract: A post includes an elongate ground piercing member having a ground piercing end and an anvil end at which is positioned an anvil. The anvil is positioned within an interior cavity of a housing with the ground piercing member extending through a second end of the housing. Relative movement of the ground piercing member and the housing brings a first hammer into contact with the anvil to drive the ground piercing member into the ground. Relative movement of the ground piercing member and the housing brings a second hammer into contact with the anvil to remove the ground piercing member from the ground. A lock is provided to selectively limit relative movement of the ground piercing member and the housing to prevent the second hammer from contacting the second striking face of the anvil.

Abstract: A fluid channeling device is for a percussive drill including a casing having an interior space, drive and valve chambers defined within the interior space, a piston disposed within the casing and having an upper end disposeable within the drive chamber and a longitudinal through-bore, and a valve for controlling flow into the drive chamber. The device includes a first member partially disposed within the drive chamber so as to extend into the piston bore when the piston end is within the drive chamber. The first member has an outer surface, an interior space and one or more ports extending between the outer surface and interior space and fluidly connectable with the drive chamber. A second member is disposed within the first member interior and has a passage fluidly connected with the valve chamber and fluidly connectable with the port(s) to establish fluid communication between the drive and valve chambers.

Abstract: Provided is a downhole percussion drill, which is installed at an end portion of a drillstring and performs drilling by giving impact blows to a drill bit at the bottomhole, which includes a hydraulic hammering mechanism 7 which uses oil having high lubricating ability as a driving medium, a hydraulic pump 8 which pressurizes the oil, and a downhole motor 9 which drives the hydraulic pump 8.

Abstract: A post driving device is disclosed. The post driving device slides to a desired position and is essentially locked in place through frictional force. As the post is driven into the ground, the device can be adjusted to a new position along the length of the post.

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: A post includes an elongate ground piercing member having a ground piercing end and an anvil end at which is positioned an anvil. The anvil is positioned within an interior cavity of a housing with the ground piercing member extending through a second end of the housing. Relative movement of the ground piercing member and the housing brings a first hammer into contact with the anvil to drive the ground piercing member into the ground. Relative movement of the ground piercing member and the housing brings a second hammer into contact with the anvil to remove the ground piercing member from the ground. A lock is provided to selectively limit relative movement of the ground piercing member and the housing to prevent the second hammer from contacting the second striking face of the anvil.

Abstract: A protective apparatus for preventing the infiltration of contaminants in a fluid-operated percussion device, having a striking tool (3) that is guided to move in a housing (2) and is driven by a percussion piston in the striking direction (arrow 1), and a seal (7) that is supported at least indirectly on the housing (2), on the one hand, and on the striking tool (3), on the other hand, and has a securing segment that is fixedly disposed with respect to either the housing or the striking tool. The seal (7) is disposed between the inner guide portion (5b) of the striking-tool guide and the theoretical striking plane (4) of the percussive piston on the striking tool (3), when seen in the direction opposite the striking direction (arrow 1), such that the countersurface (3e) for the seal, which countersurface moves relative to the securing segment (7a) of the seal (7) and is in contact with the seal, is unaffected by wear.

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: There is provided a hammer assembly (10) comprising a hammer casing (11) having a bore (12) therethrough and a drive sub (13) and retainer (15) supporting a drill bit (14). A piston (16) has a hammer end (17) adapted to strike an anvil end (20) of the drill bit (14). A porting body (21) is located in the bore (12) by expandable mounting member (22) frictionally engaged with the bore (12) by a tapered portion of the porting body (21) being urged by a top sub (23) into a tapered bore in the mounting member (22). The porting body (21) supports a non-return valve (24) in a flushing fluid path communicating with the bit face. The mounting member (22) has a small annular flange (40) adapted to engage a shoulder (41) in the casing (11) and opposed axial slots (42) extending from port apertures (43) to the upper rim (44) of the mounting member (22). The porting body (21) comprises an annular manifold (45) for pressurized fluid supplied via top sub bore (46), non return valve chamber (47) and passages (50).

Abstract: A downhole vibration tool consisting of a body assembly installed in a work string, and a drop-in dart valve assembly. An open inner bore through the body assembly allows the performance of operations through the body assembly. To activate the vibration tool, the dart valve assembly is dropped into the work string and pumped downhole into engagement with the body assembly. Once the dart valve assembly is in place in the body assembly, continued pumping of fluid will cause the tool to begin to vibrate longitudinally. When the jarring operation is finished, the dart valve assembly can be released from the body assembly and retrieved, with a wireline or coiled tubing unit.

Abstract: The collapsible land anchor of this invention includes an anchor body, a drive anvil coupled to the top end portion of the anchor body, and a runner member that is slidable longitudinally through the drive anvil between an operative position and a collapsed position. A retraction anvil is coupled to the top end portion of the runner member, and a hammer weight is carried on the runner member. In its operative position, the runner member extends beyond the drive anvil away from the cavity of the anchor body to space the drive anvil apart from the retraction anvil. Also in the operative position, the hammer weight is slidable along the runner member into the drive anvil to drive the anchor body into the ground. In the collapsed position, the runner member is displaced towards and at least partially stowed in the cavity of the anchor body.

Abstract: The invention relates to an electromagnetic hammer having a moving ferromagnetic mass, the hammer being of the type comprising a tube of non-magnetic material for standing on an element that is to be driven into the ground, said tube being surrounded by a peripheral coil connected to electrical power supply and slidably receiving the moving mass. According to the invention, the peripheral coil is subdivided into a plurality of independent coils, each independent coil being received in an associated casing and being wound around a cylindrical inner wall of said casing, the cylindrical inner walls of the casings being superposed to make up the tube in which the moving mass slides, each casing also taking up axial forces, and a junction box enabling the corresponding coil to be connected to associated electrical power supply cables.

Abstract: An impact hammer system for driving an elongate member comprising a ram member, a frame assembly, an actuator assembly, and a power source. The ram member defines a ram bore. The frame assembly supports the ram member such that the ram member may move relative to the frame assembly between first and second positions. The actuator assembly is operatively connected between the frame assembly and the ram member and is operable in extended and retracted configurations. At least a portion of the actuator assembly is disposed within the ram bore and a substantial portion of the actuator assembly extends out of the ram bore when the cylinder is in the extended position. The power source is operatively connected to the actuator assembly to place the actuator assembly in the extended and retracted configurations. Extension and retraction of the actuator assembly moves the ram member between the first and second positions, respectively.

Abstract: The invention relates to a control system for a percussion drive of an earth drilling unit having a housing, a drilling tool, a pulling or thrusting drive with pulling or thrusting means, a percussion piston, a pressure chamber belonging to the percussion piston and a pressure medium feed, which can be connected and disconnected, for the operation of the percussion piston, means being provided to connect and disconnect the pressure medium feed when the pulling or thrusting drive exceeds or falls below a specific pull or thrust.

Abstract: A concentric valve for a hydraulic rock drill featuring simple and direct fluid connections, especially suited for use with fluid storage volumes.

Abstract: A down-the-hole percussive hammer includes a casing, a drill bit attached to a lower end of the casing, and a reciprocable hammer for impacting against the drill bit. A top sub attached to an upper end of the casing includes a central passage for conducting operating air for actuating the piston. A feed tube is attached to the top sub and extends along a center axis thereof. The feed tube includes vertically spaced outlet and re-entry ports sealed from one another by a seal disposed inside of the feed tube. The outlet and re-entry ports communicate with a chamber formed in the central passage. A check valve is disposed at an upper end of the feed tube. The check valve includes an elastic sleeve arranged to overlie the outlet port and to be elastically biased away from the outlet port by pressurized operating air, whereupon the operating air passes out of the feed tube through the outlet port and then back into the feed tube through the re-entry port.

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: A method and apparatus permitting a single operator to drive elongated rods, e.g. tent stakes, into the ground for securing lines, ropes, cables and the like. The apparatus is a holder for the rod or stake that is fixed to the driving end of a pneumatic hammer. A longitudinal slot in the apparatus permits positioning of the rod so that the operator can raise the pneumatic hammer and rod into a generally vertical position and by activating the pneumatic hammer drive the rod into a fixed position. Thereafter the pneumatic hammer and holder can be readily removed from the driven rod.

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: A self-resetting impact device for use in a wellbore in order to jar a downhole tool or piece of equipment, said mechanism being attachable to a line e.g. a wireline so as to be lowerable to a required location in the wellbore, and said device comprising: means for attaching the device to a line; a housing; a hammer rod slidable relative to the housing in order to carry out a hammer stroke so as to apply an impact load; a releasable lock for holding the housing and the rod in a predetermined relative position, said lock being releasable upon application of a predetermined upward load to the device via said line so that a hammer stroke can take place; and, a reset arrangement for returning the body and the housing to the predetermined position after completion of the hammer stroke.

Abstract: A device for placing survey flags, and similar devices having stems, is operated so that the stem is locked or otherwise held to an elongated shaft or similar aligning device. Pressure on the shaft or aligning device forces a portion of the flag stem into the soil or other sound substrate. Then, an operator can carry out an operation to separate the placing device from the stem.

Abstract: An apparatus and process for removing a ball valve is provided. The ball valve removal tool provides a handle sliding along the length of a shaft. One end of the shaft is secured within an interior cavity of a ball valve while the opposite end of the shaft defines a stop member. By providing a manual sliding force to the handle, the handle impacts the stop member and transmits the force to the ball valve. The direction of the force is along the shaft of the removal tool and disengages the ball valve from the ball valve housing.

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 rod driving and extracting tool having a head connected to a handle is provided. The tool has two ends, each of which has an open bore, or rod-receiving end for communicating a section of a rod to be driven through either a first or second hollow handle section, respectively. The first and second hollow handle sections each have a second end forming a rod driving surface disposed in the handle. The first and second rod driving surfaces are on opposite sides of a generally solid, rod driving section interposed between the first and second hollow handle sections. The head has at least one additional driving surface in the form of a striking face. A rod extraction tool in the form of a cross-wise hole through the handle is provided in the solid rod driving section. Methods of using the tool to install a rod or to extract a partially exposed rod, are provided.

Abstract: A ground piercing tool of the invention includes an elongated tubular housing having front and rear openings, a head including an anvil secured in the front opening of the housing, a striker disposed for reciprocation within an internal chamber of the housing to impart impacts to a rear impact surface of the anvil for driving the tool through the ground, a reciprocation mechanism for reciprocating the striker, and a tail assembly mounted in a rear end opening of the housing that secures the striker and reciprocation mechanism in the housing. A plastic tube forms the body of the housing, and the plastic tube is secured to the head. The reciprocation mechanism is preferably an air distributing mechanism that uses compressed air to reciprocate the striker.

Abstract: A ram device has a cylindrical housing (10) in which is arranged a pressure medium actuated impact piston and a control unit for controlling the pressure medium flow into the housing (10) and which housing (10) at its rearward end is provided with a pressure medium connector (16) and is closable by a closure part (12). The closure part (12) is threadable into an end portion (22) of the housing (10) provided with an internal thread by an externally threaded section (18) and has a second threaded section (20) which stands in engagement with a counter element (22) which abuts a housing surface (40) perpendicular to the housing axis.

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: An electromagnetic hammer having a ferromagnetic moving mass, the hammer comprising both a tube (1) designed to rest via an anvil on an element to be hammered (50), carrying a peripheral coil (2), and slidably receiving the mass (14) inside itself, and electrical power supply means connected to the coil (2) to excite it in such a manner as to generate an electromagnetic field for raising the mass, the mass striking the anvil under the action of its own weight when the coil is no longer excited, the coil (2) being made by being wound around the tube (1), and the tube being made of a non-magnetic material and having means (3, 4, 5, 6) for taking up axial forces and for transmitting said forces to the anvil (13) while the mass (14) is being raised. The power supply means comprise an flywheel associated with a rotary motor and with an alternator.

Abstract: A manually operated leak detection device used in locating fluid leaks in a ground surface includes an elongated rod and a handle transversely fixed thereto. The invention is improved by fixing an anvil on the rod; slidably mounting a first collar on the rod above the anvil; slidably mounting a second collar on the rod below the anvil; connecting and spacing the first and second collars by a pair of parallel guide rods passing through the anvil, each of the guide rods lying on one side of the rod; providing a protective sheath over the anvil, the first and second collars and the guide rods, the sheath being connected to the second collar; and slidably mounting a handle over the rod and a top portion of the first collar, the handle being secured to the sheath at the top of the first collar.

Abstract: A down-the-hole percussive drill comprises a casing, a drill bit mounted at a lower end of the casing, a hollow feed tube fixed within the casing and extending along a center axis thereof, and a piston mounted for axial reciprocation within the casing for transmitting impacts to the drill bit. The upper portion forms a downwardly facing surface at the junction between the upper and lower portions. Passages for conducting lubricant-containing pressurized air are formed in the piston. At least one of those passages constitutes a vertical recess formed in the outer periphery of the piston. The piston includes a radially outwardly projecting rib disposed between upper and lower ends of the recess. Air is blocked from traveling past the rib until the rib becomes located opposite an annular groove formed in an inner surface of the casing.

Abstract: A multi-purpose impact tool, i.e. a tool for splitting wood or bricks, tamping, scraping ice of cutting trenches includes an elongated guide bar with a threaded bottom end for carrying an appropriate head, a sleeve slidably mounted on the bar for reciprocating against the head for driving the latter, and a cam lock near the top end of the sleeve locking the guide bar and sleeve together in a non-use position.

Abstract: A down-the-hole percussive drill comprises a casing, a drill bit mounted at a lower end of the casing, a hollow feed tube fixed within the casing and extending along a center axis thereof, and a piston mounted for axial reciprocation within the casing for transmitting impacts to the drill bit. The piston has a stepped configuration in that a lower portion thereof is of smaller outer diameter than an upper portion thereof. The upper portion forms a downwardly facing surface at the junction between the upper and lower portions. Air-conducting passages are formed in the upper portion of the piston and are supplied with pressurized air from the hollow feed tube. One of those passages intersects the downwardly facing surface of the upper portion of the piston. The hollow feed tube is mounted to a top sub of the drill by pins which are mounted in the top sub and extend radially into a sidewall of the feed tube, the pins being situated outside of the central passage.

Abstract: An underground utility line flagger and marker having an elongated main body having an upper end and a lower-end ground penetrator, a forwardly projecting handle at the upper end at an acute angle to the main body, the ground penetrator having a marker flagstaff-engagement recess at the bottom thereof, and a foot-driven projection on the main body whereby the staff of a marker flag lying on the ground can be inserted into the ground with the flag upright by using the handle to place the engagement recess on the flagstaff and stepping on the peg.

Abstract: An in-hole hammer for boring in ground has an elongated hollow housing carrying an internal striking piston in a piston chamber. An exchangeable boring head is threadably connected to the forward end of the housing and the striking piston impacts against the forward wall of the housing defining the piston chamber to transmit forward driving impact energy to the boring head. A boring rod which urges the hammer forwardly and rotates it about the longitudinal axis is connected to the rear end of the housing through a connecting piece non-rotatably fixed, but slidable relative, to the housing so that the axially directed impact energy produced by the striking piston is not transmitted to the boring rod.

Abstract: A improved "mud motor" for use in oil and gas well drilling includes a reciprocating valve and piston arrangement that generates power using drilling fluid media (e.g., drilling mud) pumped through an inlet port to form a differential across a piston seat. The differential pressure causes the valve and piston assembly to move down in an elongated body. Rollers then force telescoping, reciprocating fingers to rotate while absorbing the reciprocating up and down action of the valve and piston assembly. This clockwise rotation causes a transmission that includes a clutch shaft and sprags to engage a clutch housing causing the drill bit to turn. Thrust bearings allow weight to be applied to the tool to optimize drilling action. The apparatus can be used in well drilling or in the removal of obstructions such as bridge plugs, metal and rubber from the well bore.

Abstract: A compressor piston divides a first compartment into two compression chambers, while a hammer piston divides a second compartment into two drive chambers, each of the compression chambers being connected to a respective one of the drive chambers to form a closed fluid system wherein reciprocation of the compressor piston causes cyclic compression and expansion of the fluid in the compression chambers and thus in the drive chambers, to effect a cyclic impacting of the hammer piston with a bit adapter connected to the drill bit. A mud motor rotates a shaft to drive an oscillator which reciprocates the compressor piston. The oscillator can comprise roller elements in the compressor piston in engagement with canted grooves in the shaft. While drilling mud drives the motor and then passes downwardly to flush the drill bit and the borehole, the drilling mud is isolated from the closed fluid system.

Abstract: Disclosed is an improved forcible entry tool for opening locked or jammed doors by emergency personnel for the purpose of apprehending criminal suspects, gathering evidence, and preserving lives of people who become trapped by fire, earthquake, tornadoes, or by other circumstances beyond their control. The tool of the present invention comprises an elongated frame with a piercing pivot blade on the front end of the tool. The pivot blade is configured to pivot perpendicular to the frame upon penetration through a door, thereby enabling the tool operator to effectively pull back on the tool to break open an outwardly swinging door. A detachable ram head may be mounted over the front end of the frame for purposes of breaking through a door that swings inward (i.e. away from the tool operating personnel).

Abstract: A driver hammer for driving an elongated member into the earth and for extracting the member from the earth includes a hammer body and a forward driving anvil slidably mounted in the body that is engaged directly with the elongated member when the latter is driven into the earth. A conventional hammer drive mechanism is used to repeatedly impact the forward driving anvil to drive the member into the earth. When the member is to be extracted from the earth, a back driving lever, which is pivotally mounted on the hammer body, is pivoted into the position where the forward driving anvil can strike an impact surface on one side of the pivot point of the lever and a back driving anvil is engaged with a second impact surface on the opposite side of the pivot point of the lever and which is attached to the elongated member.

Abstract: A trenching tool which includes a lower portion having a blade and a guide tube. The guide or alignment tube is vertically positioned on one edge of the blade. An impact rod slips into the alignment tube and is repeatedly forced, by the operator, to impact the top of the blade, thereby driving the blade into the ground. Through a rocking motion, the channel formed by the blade is widened and the blade is again forced into the ground until the desired depth is obtained. The assembly is then removed and repositioned to extend the channel through the same procedure. The blade has either a rectangular cross section or a triangular cross section permitting the channel to be sloped automatically while the blade is being driven into the soil. A handle, preferably having shock absorption capabilities, allows the operator to slide the impact rod to obtain the driving force.

Abstract: A pneumatic downhole impact drill has a backhead for mounting an inlet check valve and a mounting hub for mounting a fluid delivery tube. A split ring has an interior circumferential groove forming upper and lower shoulders and comprises two substantially identical semi-circular ring segments. The ring segments are positioned around flanges on the backhead and the mounting hub such that the upper shoulder of the split ring slidably engages the upper surface of the backhead flange and the lower shoulder slidably engages the lower surface of the mounting hub flange to mount the backhead to the mounting hub. A first gap is formed between the outside surface of the split ring and the inside surface of the casing. A second gap is formed between the inside surface of the groove and the outside surfaces of the mounting hub and backhead flanges. Taken together, the gaps allow lateral relative movement between the mounting hub and backhead flanges.

Abstract: The invention relates to an automatically driven pile-driver drilling device for drilling into the earth with a percussion piston moving axially inside a casing, driven by a pressure medium and changeable from a forward stroke to a backstroke, with a working space having radial control openings, a guide pipe with radial control openings extending into the working space and forming a rigid part of the housing, and a control box guided into an annular chamber of the guide tube and axially adjustable in a spring-pneumatic manner.

Abstract: A compressor piston divides a first compartment into two compression chambers, while a hammer piston divides a second compartment into two drive chambers, each of the compression chambers being connected to a respective one of the drive chambers to form a closed fluid system wherein reciprocation of the compressor piston-causes cyclic compression and expansion of the fluid in the compression chambers and thus in the drive chambers, to effect a cyclic impacting of the hammer piston with a bit adapter connected to the drill bit. A mud motor rotates a shaft to drive an oscillator which reciprocates the compressor piston. The oscillator can comprise roller elements in the compressor piston in engagement with canted grooves in the shaft. While drilling mud drives the motor and then passes downwardly to flush the drill bit and the borehole, the drilling mud is isolated from the closed fluid system.

Abstract: In a percussion drill apparatus for soil drilling with a percussion piston which is moving to and fro within a housing, a control sleeve is mounted on a control tube which protrudes into the percussion piston chamber, the axial position of which determines the direction of movement of the apparatus. In order to make a reversal of movement possible a reversing chamber is connected with a control air line which runs inside the control tube and an approach chamber is connected by way of a drilling with the interior of a control tube which feeds the operating air into the percussion piston chamber. Consequently the control sleeve is moved into one direction with the aid of the control air and in the other direction with the aid of the operating air.

Abstract: The tools for the restoration of deformed lamina require a series of capable of being deformed plaques (1,5,12,13,14,18,18') provided with a central post or a stem (3,7,9,19,19') which are fixed by glues or adhesives with the use of an applicator (22,23,24), on the exterior of the deformed area of the lamina. They are therefore pulled through the post (3,7,9) and stem (19,19') towards the outside through the extractor (28,34), thus restoring the deformed plate (17). When the restoration has been completed the lamina is detached and possibly recovered for further use.

Abstract: An improved fluid actuated percussive impact tool of the valveless type adapted for down hole drilling is provided. The impact tool includes a casing, a back head, a distributor located at a first end of the casing, and an impact receiving device located at a second end of the casing. A chamber is located between the distributor and the impact receiving device. A cylinder sleeve is located in the chamber adjacent to the distributor. A first pressurized fluid passage is located between the casing and the cylinder sleeve for passing pressurized fluid from the distributor to the chamber. A piston is located in the chamber for reciprocating axial movement. Axially extending ports are located on at least one of the piston, the cylinder sleeve and the casing in the chamber for alternately supplying pressurized fluid to upper and lower chamber portions.