Abstract: Provided is an actuator and method for operating an actuator. For example, the actuator may have first and second operating phases, a housing having an opening receiving pressure, a piston inside the housing for moving along inside the housing and positioned therein for creating a first chamber between one end of the piston and the housing and a second chamber between the other end of the piston and the housing, first and second ports each capable of communicating with the pressure source during a different one of the first and second phases, an extra area chamber between the piston and the housing. In the first phase the first port may be communicating with the opening for providing pressure to the first and extra area chambers. In the second phase the second port may be communicating with the opening for providing pressure to the second chamber.

Abstract: A method for controlling a fluid operated percussive device, which inside an axially extending cylinder room (3) of a housing (2) of the percussive device includes a to and fro moveable percussive piston (1), which is adapted for performing strikes in a striking direction (A) and which includes a signal portion (4) for controlling a main valve (5), which is adapted to intermittently transmit pressure fluid to at least one driving chamber (7) for the percussive piston. An auxiliary valve (9) is controlled for transmitting fluid contact between at least one auxiliary channel means (13,14) with a channel opening in the cylinder room (3), and the main valve (5) over the signal portion (4), for switching the main valve (5) before the percussive piston, in operation, has reached at least one of said regions. The invention also concerns a percussive device and a rock drilling machine.

Abstract: A control system for use in conjunction with a primary power system and operable to control a pneumatically powered hand-held tool broadly comprises an air delivery assembly operable to communicate with a pressurized air source; a control assembly including an exhaust line from the primary power system and to the control assembly, a spool valve in fluid communication with the supply line and the exhaust line, and a control line in fluid communication with the spool valve and the hand-held tool; a tool assembly comprising the hand-held tool for performing delicate hand working operations; and a housing for at least partial storage of the air delivery assembly and the control assembly. The primary power system and the control system operate in conjunction with each other to both power and precisely control a pneumatically powered hand-held tool.

Abstract: An oil pulse tool including: a brushless motor which includes stator windings; a drive circuit configured to apply a driving voltage to any of the stator windings of the brushless motor at a predetermined timing; an oil pulse mechanism portion configured to be rotary driven by the brushless motor; and an output shaft which is connected to the oil pulse mechanism portion, wherein the drive circuit changes an advance angle of the driving voltage in accordance with a rotational position of the oil pulse mechanism portion.

Abstract: A shock-absorbing element is disposed frontward of an interjacent element within a housing of an impact tool, and a washer is disposed rearward of and adjacent to the shock-absorbing element. The interjacent element is configured to come in contact with the washer when the interjacent element is caused to advance by an impactor's strike under no-load conditions. A sleeve disposed rearward of and adjacent to the washer is configured to position the shock-absorbing element and the washer, and to allow the interjacent element to move rearward and frontward inside the sleeve.

Abstract: A pneumatic impact device and method provide a high powered striking force against a target object. The device includes a core shell that houses a piston sub-assembly and a sear arm sub-assembly, and that further defines a forward gas chamber and a rearward gas chamber. The rearward gas chamber is loaded with compressed fluid via a handle actuator. A mostly external sear trigger assembly responds to the impact of a striker plate against the target object, thereby releasing a sear arm that then releases a piston, which is then accelerated forward by the compressed fluid charge. The device can be re-set manually via compressed fluid (e.g., air) in one embodiment, or automatically via a spring mechanism in another embodiment.

Abstract: Pressurised air pick device with variable control that comprises a cylinder and piston assembly for actuating a picking member, and a distribution portion with variable control of the pressurised air to said cylinder and piston assembly, the distribution portion including an upper body, a lower ring and a movable fluid-distribution slider capable of sliding between the body and the ring, characterised in that the distribution portion is housed in the cylinder of the cylinder and piston assembly at the upper portion thereof and coaxially therewith, the variable control for the fluid is housed in the head of the cylinder closing the upper portion of the cylinder connected to a fluid-supply section, and said upper portion of the cylinder includes two channels for conveying pressurised air in tight communication with the distribution portion through the radial channels thereof.

Abstract: A damping device for inserting into a housing of an impulse producing drill machine, for damping Shockwave reflexes from a drill string connected to the drilling machine, is distinguished in that a first damping piston (7) for direct or indirect action against the drill string and for applying a pressure in the direction of the drill string an a second damping piston (9) for applying pressure in the direction against the drill string against a fixed stop (11) arranged in the housing, wherein the first (7) and the second damping piston (9) are arranged to co-operate for joint damping action with a drill bushing or shank adapter in a certain relative position. The invention also concerns a drilling machine.

Abstract: The handheld power tool (10) has a pneumatic striking mechanism (12) that has an exciter element (17), a striking element (17) and an anvil (28). A mechanical spring 8(32) exerts force onto the anvil (26) in the direction opposite from the striking direction (24) of the pneumatic striking mechanism (12).

Abstract: A device for vibrating tubing as it is inserted into a wellbore is disclosed. The device has a fluidic switch that has no moving parts. The fluidic switch is connected to a piston that oscillates back and forth in a cylinder. The piston is the only moving part. As the piston oscillates, it blocks and unblocks openings in the cylinder or other components. The movement of the piston controls the timing of the oscillation, and also generates an impulse or vibration. The vibration may reduce the friction between the tubing and the wellbore.

Abstract: A device for driving various objects using combustible fuel. Embodiments are contemplated in which the driver could be a post-driver, a power shovel, a jack-hammer or other devices. Typically, the device includes a body with a combustion chamber. A fuel injection valve selectively supplies fuel to the combustion chamber where it can be ignited using an ignition module. A piston is movable within the body to impact the ram responsive to combustion in the combustion chamber.

Abstract: A quick assembly pneumatic tool may be connected to a tool bit and has a housing, an anvil casing, a rear cover, an air inlet assembly, a rotor assembly and an impact assembly. The housing has a handle and a rotor casing. The rotor casing is formed on the handle and has a front chamber and a rear chamber. The anvil casing and rear cover respectively cover the front and rear chambers. The rotor assembly is mounted in the rear chamber and is selectively driven by the air inlet assembly. The impact assembly is mounted in the front chamber and the anvil casing and is selectively rotated by the rotor assembly. The separate rotor and anvil casings allow the rotor and impact assemblies to be inserted respectively in the front and rear chambers so that assembling the pneumatic is easy and quick.

Abstract: According to an aspect of the present invention, there is provided a rotary striking tool includes: a motor; an oil pulse unit that is driven by the motor; an output shaft that is coupled to the oil pulse unit so that a tip tool can be attached to the output shaft; a first detection unit that detects a rotation angle of the motor and outputs a first output signal; a second detection unit that detects an impact generated at the oil pulse unit and outputs a second output signal; and a control unit that controls a rotation of the motor, wherein the control unit uses a portion of the second output signal based on the first output signal for control of the rotation of the motor.

Abstract: The invention relates to a pulse generator (18) in an impulse generator (2) for a cutting tool (12), which pulse generator (18) is intended to transfer energy from a propulsion device (14) to impulses in the tool (12), where the pulse generator (18) comprises a rotatable cylinder drum (28) comprising at least one piston cylinder (30, 86, 88, 90, 92, 94, 96, 98), in which piston cylinder (30, 86, 88, 90, 92, 94, 96, 98) is arranged at least one piston (32, 87, 89, 91, 93, 95, 97, 99), which piston (32, 87, 89, 91, 93, 95, 97, 99) is arranged to compress fluid (29) during rotation of the cylinder drum (28), and that the cylinder drum (28) is arranged to discharge the fluid (29) to the propulsion chamber (6) in the discharge position of the piston (32, 87, 89, 91, 93, 95, 97, 99) via at least one opening (31, 72, 74, 76, 78, 80, 82, 84) opening into the piston cylinder in order to produce an impulse in the tool (12). The invention also relates to an impulse machine comprising an impulse generator (2).

Abstract: The invention relates to a method for breaking rock to be drilled in rock drilling, in which method the rock to be drilled is subjected to successive stress pulses via a tool. The method comprises stress pulses being exerted on the rock at a high frequency, and the load proportion calculated on the basis of the values of the frequency and the length (tp) of the stress wave being at least 0.075.

Abstract: A pressure-fluid-operated percussion device includes a frame allowing a tool to be arranged movably in its longitudinal direction. Pressure liquid is fed to the percussion device and returned to a pressure liquid tank. A stress pulse is produced in the tool utilizing pressure of the pressure liquid. A pressure liquid source maintains pressure in the working pressure chamber. Pressure liquid is intermittently fed to the percussion device such that the pressure liquid pushes a transmission piston into a predetermined backward position. Pressure liquid is alternately discharged rapidly from the percussion device so that the pressure of the pressure liquid in the working pressure chamber and the pressure liquid flowing from the pressure liquid source pushes the transmission piston towards the tool, generating a stress pulse in the tool.

Abstract: A pneumatic percussion tool (1) for demolition and/or breaking work in for example concrete and connectable to an insert tool (2). The percussion tool has a percussion cylinder (4), a piston (5), arranged to travel in the bore of the cylinder (4), a buffer (8), and a valve unit (6), designed to act on the piston (5) during operation and produce a repetitive reciprocating travel in the bore of the cylinder (4) by alternately applying pressure to the upper or lower end of the cylinder (4) while the insert tool (2) is subject to influence by the stroke of the piston (5) when this is at its dead centre at the lower end of the cylinder (4). The percussion tool comprises a means (11) of preventing the piston's reciprocating motion when the buffer (8) reaches a predetermined degree of wear and the tool is not pressed against any object being worked.

Abstract: A hammer device in the form of a needle gun. The gun includes a cylinder housing containing a cylinder, in which a flying piston is displaced and an anvil, against which the piston strikes. A needle carrier is located on the anvil, and the needles of the gun are held in the carrier so that the needles can be longitudinally displaced. To reduce the wear on the needle carrier and to preserve the needle heads of the needles, the needle carrier is configured from several layers, at least in the vicinity of the guide plate. The layers are of alternating hard and soft material.

Abstract: A control system for use in conjunction with a primary power system and operable to control a pneumatically powered hand-held tool broadly comprises an air delivery assembly operable to communicate with a pressurized air source; a control assembly including an exhaust line from the primary power system and to the control assembly, a spool valve in fluid communication with the supply line and the exhaust line, and a control line in fluid communication with the spool valve and the hand-held tool; a tool assembly comprising the hand-held tool for performing delicate hand working operations; and a housing for at least partial storage of the air delivery assembly and the control assembly. The primary power system and the control system operate in conjunction with each other to both power and precisely control a pneumatically powered hand-held tool.

Abstract: A method for producing Shockwave pulses in a tool direction (R) of a pulse machine (1) having a housing (2), wherein an impulse piston (4) is arranged, wherein the impulse piston is influenced by a first force in a direction opposite to said tool direction through a first fluid pressure (Pi) in a first chamber (7), and by a second force in said tool direction, wherein a Shockwave pulse is produced through a rapid relief of the first fluid pressure after displacement of the impulse piston (4) relative to the housing in a direction opposite to the tool direction, is distinguished in that the length of the shock wave is controlled by the length (L) of said displacement is regulated. The invention also concerns a device, rock drilling machine and a rock drilling rig.

Abstract: An impact force is transmitted to a tip end tool due to the changes of the air pressure within an air chamber generated by the reciprocal operation of the piston within a striker. The attachment portion of a tip end tool holding member for holding the tip end tool to a cylinder casing is sandwiched between buffers disposed in the two directions of the axial direction of the tool thereby to elastically support the tip end tool holding member to be movable in the two directions of the axial direction of the tool.

Abstract: A control system for use in conjunction with a primary power system and operable to control a pneumatically powered hand-held tool broadly comprises an air delivery assembly operable to communicate with a pressurized air source; a control assembly including an exhaust line from the primary power system and to the control assembly, a spool valve in fluid communication with the supply line and the exhaust line, and a control line in fluid communication with the spool valve and the hand-held tool; a tool assembly comprising the hand-held tool for performing delicate hand working operations; and a housing for at least partial storage of the air delivery assembly and the control assembly. The primary power system and the control system operate in conjunction with each other to both power and precisely control a pneumatically powered hand-held tool.

Abstract: A power tool having a housing divided into two parts which are interconnected by a thread joint. Internal threads are provided on the housing parts. A tubular connection element has two external axially spaced thread sections which are provided for engagement with the internal threads on the housing parts. The tubular connection element has a thin walled waist section located between the external thread sections to provide a certain elastic deformation as a tightening torque is applied on the thread joint to thereby increase the clamping length of the thread joint. A resilient ring is carried on the waist section and is arranged to be elastically deformed by squeezing between the housing parts and the connection element at tightening of the thread joint, thereby providing a rotation locking friction force on the thread joint.

Abstract: A pneumatic impact tool includes a housing, an accumulation chamber, and a piston. The housing defines a longitudinal passageway with a rear end and a front end and a passageway gas port. The accumulation chamber has a accumulation chamber gas port connectable to a gas supply and a inner gas port in fluid communication with the longitudinal passageway. The piston is inserted in the longitudinal passageway and slides between a rest position wherein the piston is juxtaposed to the rear end of the longitudinal passageway and an impact position wherein the piston is juxtaposed to the front end of the longitudinal passageway. The piston moves from the rest position to the impact position when gas is inserted in the longitudinal passageway through the passageway gas port and is propelled therebetween by pressurized gas contained in the accumulation chamber.

Abstract: A percussion mechanism for a repetitively hammering hand power tool in the form of a rotary hammer has a striker movable axially forward and backward in a guide barrel and imparting impacts directly and without any intermediate parts to an end section of a tool bit that is insertable into the hand power tool, a device that exerts pressure on the striker, by which the striker is capable of being set into a forward motion in the direction of the tool bit, a blocking element, with which the striker is blockable in its forward motion, and the striking frequency of the striker is adjustable by controlling the blocking time of the blocking element, so that the striking frequency of the striker depends on how long the blocking element blocks the forward motion of the striker.

Abstract: A superior ram-boring machine “mole”, employing compressed air to drive a reciprocating piston onto either forward or rearward anvils thereby imparting momentum. Wherein a control valve received into the rear of the piston interacts with ports therein determining its stroke characteristics. The end receiving impacts, and hence the direction of action are determined by accurately positioning the control valve forwardly or rearwards. Incorporating a robust, air-on, fail-safe “Rapid Reverse” mechanism, actuated by a small rotation of the air hose. Whereby guide means and an indexing collar incorporating or comprising encompassing spring or elastic means having inter-engaging features deforms by flexing and or compression to disengage and is biased to re-engage with corresponding features to position and lock the control valve into forward and reverse settings; thereby assisting easy switching, location and retention of operating positions.

Abstract: A pulse drilling machine (1; 1?) for the generation of shock wave pulses in a tool direction (R) including a housing (2) wherein an impulse piston (4; 4) is arranged, and including means (9) for abrupt change of a fluid pressure influencing the impulse piston in order to achieve a force resultant on the impulse piston in the tool direction and thereby generate a shock wave pulse in a drill string (13; 13?) which is connected to the machine, wherein inside the housing there is arranged a first fluid chamber (14; 3?) inside which a pressure fluid in operation is arranged to exert a pressure in the tool direction on the impulse piston. The machine is distinguished by a fluid flow channel (11; 18; 19), which includes means for damping a fluid flow flowing from said first fluid chamber through the fluid flow channel obtained when influencing the impulse piston (4; 4?) in a direction opposite to the tool direction (R) by rock reflexes in the drill string during drilling.

Abstract: A pneumatic screw driver includes: a tool body; a nose portion; a main air chamber; a hammering cylinder; a driver bit integrally combined with a hammering piston in the hammering cylinder; an air motor; a valve housing provided in an air passage between the main air chamber and the air motor; a stop valve piston provided in the valve housing; a stop valve stem coaxially provided with the stop valve piston; a timer chamber connected to the hammering cylinder; a first pipeline and a second pipeline respectively formed at upper and lower positions in a lower portion of the stop valve stem; and a upper end proximal portion of a contact member provided slidably in a driving direction. The upper end proximal portion of the contact member is provided engageably with the stop valve stem. The first pipeline and the second pipeline are arranged so as to close the first pipeline after closing the second pipeline by moving the stop valve stem upward from a bottom dead center.

Abstract: A hand-held drill hammer has a housing, a shaft (12) connected to a drive shaft (30), and a lifting bearing (14). The lifting bearing (14) is supported and the shaft (12) for converting rotary motion into a reciprocating motion. In a first switching configuration, a percussion drive connection exists between the shaft (12) and the lifting bearing (14). In a second switching configuration, the percussion drive connection is interrupted. The lifting bearing (14) may be fixed with respect to a reference system of the housing in the second switching configuration.

Abstract: An exemplary embodiment of the jet hammer includes an outer sleeve, impact assembly, and a valve assembly. The impact assembly is positioned in sliding relation to the outer sleeve to provide the impact of the jet hammer. The valve assembly generally comprises a cap screw, adjustment sleeve, valve port, inner compression spring, outer compression spring, and lock nut. The inner compression spring is relatively less compressible than the outer compression spring. In operation, fluid enters the valve assembly and acts on the compression springs forming an operational seal between the valve assembly and the impact assembly. In response, the outer sleeve is slidingly displaced from the impact assembly thereby compressing a main compression spring positioned along the mandrel shaft. Once the pressure acting on the valve assembly is released, the main compression spring decompresses forcefully causing the outer sleeve to impact a connection port, bit, tool, or other member attached to the upper end of the mandrel.

Abstract: A pneumatic percussion mechanism for a hand-held power tool includes a percussion piston (23) displaceable in a guide tube (21) for applying impacts to an anvil (24), a driving member (22) reciprocating in the guide tube (21) for driving the percussion piston, and an air spring (25) for transmitting a driving torque from the driving member (22) to the percussion piston (23) and directly switchable on and off by the anvil (24).

Abstract: A portable power tool includes a housing, and an impact mechanism movably supported in the housing and having a front opening for receiving a working implement and a hammer piston for delivering hammer blows to the working implement. The impact mechanism is supported in the housing by a pivot device in a point located between the forward and rear ends of the impact mechanism and allowing longitudinal and pivotal movements but preventing in the support point radial and rotational movements of the impact mechanism relative to the housing. A resilient device is located at a distance from the pivot device and is arranged to bias the impact mechanism to a neutral position relative to the housing and to absorb vibration movements of the impact mechanism to protect the housing against such vibration movements.

Abstract: The invention relates to a method for controlling a pressure fluid operated percussion device comprising a working chamber for pressure fluid and in the working chamber a transmission piston installed movably with respect thereto so as to enable a tool installed in the percussion device to be pressed against a material to be broken in order to generate a stress pulse, and to a percussion device. The method comprises adjusting the length of the stress pulse by adjusting the time during which pressure influences the transmission piston. The percussion device comprises an adjustment element and adjustment means for adjusting the influence time of the pressure of the pressure fluid being fed via a control valve and influencing the transmission piston.

Abstract: A discontinuous drive power tool assembly for generating rotational torque includes a spindle having a first end portion and a second end portion. The first end portion of the spindle is configured to engage and rotate an object. The tool assembly also includes a pulse hammer selectively engagable with the second end portion of the spindle, and a motor that includes a motor shaft engagable with the pulse hammer. The motor is configured to rotate the pulse hammer. The tool assembly also includes a rotational position sensor disposed adjacent the motor. The rotational position sensor is configured to measure the rotational position of a second portion of the motor shaft which is opposite the first end portion of the motor shaft during operation of the tool assembly.

Abstract: A percussion device (1) with a reciprocating percussion piston (3), includes a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be periodically pressurized for back-driving of the percussion piston (3). The percussion device includes at least one driving piston (7) arranged for actuating the back-driving of the percussion piston (3) wherein a portion of said driving piston (7) is arranged to enter into the second chamber (8) for pressure actuating on a driving surface of the driving piston by pressure medium being present in this chamber in the direction of back-driving, wherein the driving piston (7) includes means for back-driving co-operation with the percussion piston (3), and wherein the driving piston (7) is free for axial movement with respect to the percussion piston (3), opposite the direction of back-driving. The invention also concerns a method and a rock drilling machine.

Abstract: A percussion mechanism for a repetitively hammering hand power tool, whose striking frequency and striking intensity are controllable independently of one another, has a striker (2), movable axially forward and backward in a guide barrel (1), and a device (5) exerting pressure on the striker (2), as a result of which the striker can be set into a forward motion in the direction of a tool bit (4) that is insertable into the hand power tool. A blocking element (10) is also provided, with which the striker (2) is blockable in its forward motion, and the striking frequency of the striker (2) is adjustable by controlling the blocking time of the blocking element (10).

Abstract: An intensifier is operable to supply force and includes a housing defining a cavity. A ram is slidably positioned within the cavity and partially extends from the housing. The ram is moveable between retracted and extended positions along a longitudinal axis. First and second links are rotatably coupled to one another about an axis of rotation and are selectively moveable between retracted positions where the axis of rotation is not axially aligned with the ram and partially extended positions where the axis of rotation is axially aligned with the ram. The intensifier includes a plurality of power pistons axially aligned with each other and the ram. The power pistons are selectively operable to provide an output force to the ram when the first and second links are in the partially extended positions.

Abstract: The present invention relates to a control device for an impulse-generating device for inducing a shock wave in a tool, in which said impulse-generating device comprises an impact element for transmitting said shock wave to said tool, a counter pressure chamber acting against the impact element and a device for reducing a pressure in the counter-pressure chamber. The control device comprises control means for regulating the reduction of the pressure in said computer-pressure chamber. The invention also relates to an impulse-generating device.

Abstract: The invention relates to a method for controlling the operation of a pressure fluid operated percussion device and to a pressure fluid operated percussion device. The method comprises influencing the shape of a stress wave by setting a suitable clearance between a transmission piston and a tool. The percussion device is provided with means for setting the clearance between the transmission piston and the tool.

Abstract: A hydraulic breaker hammer comprises a housing (10) with a longitudinal bore (12), a cylinder sleeve (14), and a cylinder sleeve (14) engaging rear end cover (16), a hammer piston (15) reciprocally powered in the cylinder sleeve (14) for delivering blows to a working implement inserted in a guide sleeve (20) at the front end of the bore (12), wherein the guide sleeve (20) is provided with radial openings (22a,b) for communication of lubricant from a lubricant supply passage (21) in the housing (10) to the inside of the guide sleeve (20), and the guide sleeve (20) is provided with external seal rings (23 a-d) forming annular compartments located between the lubricant supply passage (21) and the radial openings (22 a,b) for spreading lubricant on the outside surface of the guide sleeve (20), a distribution valve (31) communicating with the pressure fluid source and the cylinder sleeve (14) and comprising both a clearance seal means (44) and a seat seal (45,46) for improved tightness, and a pressure accumulator

Abstract: It is an object of the invention to provide a technique for further improving the vibration reducing performance in an impact tool. A representative impact tool includes a tool body, a cylinder housed within the tool body, a dynamic vibration reducer having a weight that linearly moves under a biasing force of an elastic element, wherein the dynamic vibration reducer reduces vibration of the tool body during hammering operation by the movement of the weight in the axial direction of the tool bit, and a mechanical vibration mechanism that actively drives the weight by applying external force other than vibration of the tool body to the weight via the elastic element. The weight and the elastic element are disposed on the axis of the tool bit and between an inner wall surface of the tool body and an outer wall surface of the cylinder in such a manner as to cover at least part of the outer wall surface of the cylinder in the circumferential direction.

Abstract: An air tool is composed of a main rod, a sleeve, a compression spring and a connector. The main rod possesses a plugging bar, a blocking annular surface, and a through bar having a connecting portion in its end portion. The through bar is mounted with the compression spring and inserted in the sleeve. The sleeve has a blocking annular surface to block the compression spring. The connector is screwed with the end of the main rod. In addition, via the elastic counterforce of the compression spring, the impact of the air tool generated while operating the air tool can be weakened so as to prevent the air tool from being damaged and enable a user to hold the air tool easily.

Abstract: A percussion device for a rock drilling machine or the like, which includes providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The the stress pulse is provided by way of a stress element of liquid, which is supported to a body of the percussion device. The stress element is subjected to pressure and correspondingly the stress element is released abruptly, whereby the stress energy is discharged as a stress pulse to the tool in direct or indirect contact with the stress element.

Abstract: A pile driver provided with a housing and at least one body connected with the housing so as to be movable back and forth over a predetermined path, the pile driver being further provided with a drive for moving the body back and forth over the path for the purpose of pile-driving, the pile driver comprising at least two parts movable relative to each other, respectively having at least a first type of sliding surface and at least a second type of sliding surface which during pile-driving slide along each other and between which there is a lubricant, wherein the first type of sliding surface is provided with polyether ether ketone.

Abstract: The invention relates to a ground working implement and to a method for introducing a working element into the ground, using vibrations. By means of a vibration generator vibrations are generated and transmitted to the working element during its introduction into the ground. According to the invention a gentle vibration generation and transmission are brought about in that the vibration generator has at least one vibrating piston mounted in linearly displaceable manner in a casing spaced from the working element. The vibrating piston is driven in oscillating manner in the casing for generating vibrations. The vibrations are transmitted via the casing to the working element.

Abstract: An improved impact power tool for carving and engraving an article comprises an air delivery system operable to communicate with a pressurized air source; a drive assembly operable to receive air from the pressurized air source via the air delivery system; a hand held device in driven communication with the drive assembly; and a housing for storage of the air delivery system and drive assembly. The tool includes an improved valve design, a throttle bias valve, and an air storage tank housed within the housing, and an improved housing construction. The improved valve design and air storage tank enable greater stroke speeds of a work tool over a wider power range while also improving the crispness and speed of the impact reaction time over the entire range. The throttle bias valve is in communication with an additional exhaust path, such that the bias valve allows improved control of the hand held device and improved operation over a wider range of air pressures.

Abstract: A hammer device in the form of a needle gun. The gun includes a cylinder housing containing a cylinder, in which a flying piston is displaced and an anvil, against which the piston strikes. A needle carrier is located on the anvil, and the needles of the gun are held in the carrier so that the needles can be longitudinally displaced. To reduce the wear on the needle carrier and to preserve the needle heads of the needles, the needle carrier is configured from several layers, at least in the vicinity of the guide plate. The layers are of alternating hard and soft material.

Abstract: A pneumatic motor includes a shell, two covers, a cylinder and a rotor. The shell defines a space, at least one inlet in communication with the space and at least one outlet in communication with the space. Each of the covers defines at least one radial channel and at least one arched channel in communication with the radial channel. The covers are disposed in the central space of the shell while the radial channel is in communication with the inlet. The cylinder defines a central space and at least one inlet in communication with the central space. The cylinder is located between the covers so that the central space thereof is in communication with the arched channels of the covers and that the inlet thereof is communication with the inlet of the shell. The rotor includes a plurality of fins movably mounted thereon.

Abstract: A method of generating a stress pulse, and an impact device. In the method, pressure fluid is fed as pressure pulses to a working chamber residing between the frame of the impact device and a tool such that the resulting force presses the tool towards the material to be processed. The impact device comprises a working chamber and device for conveying pressure fluid as pressure pulses thereto such that a force is produced between the frame of the impact device and a tool to press the tool towards the material to be processed.

Abstract: An impact hammer drill capable of performing drilling operation at a high speed with low noise and without requiring a large thrust. The drill includes a main shaft rotatable by an output shaft of a motor, and a spindle having an impact-receiving section and disposed over the main shaft slidably in its axial direction and rotatable together with the rotation of the main shaft. A piston is reciprocatingly slidably disposed over the main shaft for impacting against the impact-receiving section. A piston drive unit is disposed for driving the piston with a compressed fluid. A compressed fluid supplying unit is disposed for supplying the compressed fluid to the piston drive unit. A drill bit is attachable to the spindle. When performing drilling operation, the drill bit is imparted with a combined rotational motion and the reciprocal impact motion.