Abstract: The invention relates to a driving device, in particular a screw foundation driving device, having an anchor with a rotational axis for receiving a driving tool, an outer rotor, which is arranged concentrically to the rotational axis of the anchor and can be rotationally driven by a motor, and an impact device from which an impact energy can be introduced into the anchor. By means of rolling bodies arranged circumferentially on the anchor, the anchor is mounted in the outer rotor in such a way that a relative movement between the anchor and the outer rotor can be executed in the direction of the rotational axis and a torque about the rotational axis can be introduced from the outer rotor to the anchor via the rolling bearings.

Abstract: Disclosed is a method for driving a screwable foundation, which comprises a thread-type external helix that has a pitch on the outer contour thereof, into the ground. In said method, a striking force is applied to the screwable foundation in the driving direction in alternation with or at least temporarily simultaneously with a torque when the screwable foundation is driven into the ground.

Abstract: An impact tool is provided which has a driving mechanism 120, 140 that drives a tool bit 119, a motor 110 that drives the driving mechanism 120, 140, an inner housing 103 that houses the driving mechanism 120, 140, an outer housing 101 that has an internal space for housing the inner housing 103 and the motor 110, an opening 193 that leads from the outside to the internal space of the outer housing 101, and a covering member 195 that covers the opening 193.

Abstract: A pile hammer includes a cylinder, a piston displaceably guided in the cylinder, and a striker displaceably guided in the cylinder. The striker is disposed underneath the piston in the operating position of the pile hammer. A combustion chamber is delimited axially by a face surface of the striker that lies in the interior of the cylinder and by a face surface of the piston. Using at least one fuel feed device a predetermined amount of fuel can be introduced into the combustion chamber during each work cycle. An end ring is disposed on the cylinder for forming a capture groove. The piston is provided with a step that projects outward, which makes contact with the capture groove in the upper end position of the piston, and the end ring is elastically connected with the cylinder.

Abstract: A rotating cone drill bit includes a plurality of mud nozzles extending from the bit body, which are thermally fitted by controlling the temperature differential of 300° F.-900° F. depending on the corresponding materials of the elements to be fitted, the amount of fit desired, and the diameters of the elements to be fitted and which provide substantially obstruction-free mud paths toward the wellbore bottom. The bit has a plurality of reduced diameter cutter assemblies, each having a journal projecting from a corresponding leg. The journal has at least two cylindrical bearing surfaces and an annular groove formed therebetween and a spindle. An annular retention segment is rotatably mounted in the groove. The retention segment has an outer radial surface engaging a portion of one of the bearing surfaces of the cone, and an energy beam welding area fusing substantially the entire engaging surfaces of the retention segment and the cone.

Abstract: A rotary spindle 4 for a power tool such as a hammer drill is disclosed. The spindle 4 comprises a first spindle part 402 for rotation about its longitudinal an axis by means of a motor and having an inwardly directed rim 406, and a second spindle part 404 for supporting a drill bit of the hammer drill and having an outwardly directed rim 410. The second spindle part 404 extends through an aperture 408 in the first spindle part 402 and rims 406, 410 cooperate with each other to prevent removal of the second spindle part 404 from the first spindle part 402. A circlip 414 locks the first and second spindle parts 402, 404 together and maintains o-rings 412 under compression.

Abstract: A driving unit comprises a pneumatic head for being combined to a pneumatic tool; a front end of the pneumatic head being installed with a push rod; a driving unit having a slender driving rod at a front end thereof; the push rod serving to push the driving unit; an elastomer; a casing having a receiving space; the elastomer being received in an upper end of the receiving space; and the driving unit being received in an upper end of the receiving space and resisting against the elastomer; a rotating unit having an engaging portion at a lower end thereof; the rotating unit being received in a lower end of the receiving space; and an upper side of the rotating unit having a contact portion; the configuration of the contact portion being corresponding to one end portion of the driving unit.

Abstract: An apparatus for providing percussion action in a rotary power tool having a rotary output shaft, the apparatus comprising at least one moveable mass adapted to have a component of movement parallel to the axis of the rotary output shaft to cause impacts to be applied to a working member of the tool; and a device for intermittently converting rotary movement of the rotary output shaft into movement of at least one the moveable mass to cause the impacts to be applied to the working member.

Abstract: The inventive rotary percussion device (1) used for driving at least one drill column (2) disposes of a percussion device (6) and a rotary device (5) and of an insertion end (3), which is rotatably mounted in a device body (8) and which has an axial boring, in which a percussion piston (4) is displaceably mounted. The insertion end (3), which is connected to the drill column (2) by a connection piece (33), is driven by the rotary device (5), and the percussion piston (4) mounted in the insertion end (3) is driven independently thereof by the percussion device (6). The percussion energy transmitted to the drill column (2) via the percussion piston (4) has, as a result, largely reduced influences upon the insertion end (3) that, according to the invention, is decoupled from the percussion device (5) so that premature material fatigue is prevented. In addition, the noise emissions occurring during the operation of the inventive rotary percussion device (1) are largely reduced.

Abstract: A bi-directional power tool for driving fasteners and for drilling purposes. The power tool comprises a rotary piston driving mechanism and a linear sliding member that transform a longitudinal motion of a piston in a cylinder to a rotation movement of a working head. The power tool includes a driving unit that comprises a pressure generator and a controller that controls the operation of the tool. Alternatively the power tool can be operated manually.

Abstract: A fluid-activated, percussive impact tool has a piston therein that reciprocates longitudinally but not rotationally. The piston activates a wrap spring clutch to rotate the drill steel. A removable splined nut in combination with the tool's housing restrains rotation of the piston, while permitting longitudinal reciprocation of the piston.

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.

Abstract: A fluid-activated, percussive impact tool has a piston therein that reciprocates longitudinally but not rotationally. The piston activates a wrap spring clutch to rotate the drill steel. A removable splined nut in combination with the tool's housing restrains rotation of the piston, while permitting longitudinal reciprocation of the piston.

Abstract: A clutch assembly transmits rotary motion in a percussive apparatus to a drill steel. The clutch assembly includes a first hub having a first cylindrical surface formed thereon. A second hub which is substantially rotationally coupled to the drill steel has a second cylindrical surface formed thereon. The second cylindrical surface is coaxial with the first cylindrical surface. A wrap spring engages a portion of both the first cylindrical surface and the second cylindrical surface, wherein relative rotary motion between the first hub and the second hub is permitted in a first direction and restricted in a second direction. The wrap spring clutch transmits motion supplied from a rifle bar assembly as well as a plunger bar arrangement.

Abstract: A clutch assembly transmits rotary motion in a percussive apparatus to a drill steel. The clutch assembly includes a first hub having a first cylindrical surface formed thereon. A second hub which is substantially rotationally coupled to the drill steel, has a second cylindrical surface formed thereon. The second cylindrical surface is coaxial with the first cylindrical surface. A wrap spring engages a portion of both the first cylindrical surface and the second cylindrical surface, wherein relative rotary motion between the first hub and the second hub is permitted in a first direction and restricted in a second direction. The wrap spring clutch transmits motion supplied from a rifle bar assembly as well as a plunger bar arrangement.

Abstract: A drill head is disclosed, for use to drill a hole in a front of hard material such as rock, which comprises a main body acting at a central support, an upwardly projecting spindle secured on top of the main body, the spindle having a vertical axis, a fixation head on top of the spindle for detachably connecting it to a drill shaft operable in use to rotate the drill head about the vertical axis of the spindle and to pull it up toward the front hard material to be drilled, and at least two impact hammers mounted onto the main body in such a manner as to fragment, in use the hard material of the front along at least one circular path centered onto the vertical axis, each impact hammer having a hollow casing, a pneumatically-operated, impact generating assembly enclosed within the casing, and a drill bit actuated by the impact-generating assembly.

Abstract: An impact hammer assembly for use on a drill head intended for drilling hard material, such as rock. The hammer comprises an elongated hollow case opened at one end and a drill bit provided with a rear stem that is mounted in the hollow case, through its open end, for free rotation and limited slidable displacement. A pair of pins extends transversally through the case on either side of the stem of the drill bit to retain the same in the case.

Abstract: An improved hammer driver includes a body with an outward flange on a lower portion thereof, a removable socket member adapted to driving a nut or bolt, a rotary member interconnecting the body and the socket member and including a radially extending rotary arm for being actuated to rotate the socket member, an impact member slidably sleeved on the body above the outward flange for sliding axially on the body to hammer against the outward flange, and a transmission device for rotating the rotary member and hence socket member when the outward flange of the body is hammered by the impact member.

Abstract: A rock drill apparatus has features that allow it to be attached to a conventional impact tool. The rock drill attachment has a housing that is secured to the impact tool carriage below the hammer of the impact tool. A tappet is carried in the housing of the rock drill attachment for axial movement in response to blows from the hammer. The tappet is nonrotatable with respect to the housing and is adapted to deliver blows to a tool shank. A conversion device is coupled between the tappet and the tool shank to convert downward movement of the tappet into rotation of the tool shank prior to the impact of the tappet on the tool shank. A spring moves the tappet away from the tool shank after impact for repeating the cycle. The conversion device includes a sleeve with inclined splines that engage inclined splines on the tool shank. A clutch locks the sleeve to the tappet during downward movement to rotate the tool shank. During upward movement, the clutch allows the sleeve to rotate with respect to the tappet.

Abstract: The invention is a rotary drive system for a jack hammer which incorporates a plurality of annular sleeves to transfer the motion generated by the piston to the tool holder and thereby allows the piston to strike the tool when the piston moves in the forward direction. Upon the return stroke of the piston, the annular sleeves are provided with mutually engaging helical splined teeth which causes a partial rotation of the tool holder and thereby provides rotation of the tool holder prior to the piston's next impact with the tool. All of the components are annular and, therefore, easily assembled into the bore of the jack hammer housing. Also, the use of helical splines significantly reduces the frictional resistance of the complete system.

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.