Abstract: A hydraulic rock breaking machine and an apparatus and method for monitoring operation of the same is provided. The apparatus includes at least one pneumatic sensor arranged for monitoring an inner space of the machine and at least one control unit configured to receive and process the pneumatic sensing data.

Abstract: A machine tool includes a tool holder and a pneumatic striking mechanism that includes, on a working axis, an exciter piston, a beater, and a pneumatic chamber disposed between the exciter piston and the beater. The exciter piston is drivable by the motor and includes a pot-shaped base body, a seal ring, and a tube-shaped cladding body. The pot-shaped base body has a lateral wall enclosing the working axis and a collar which protrudes in a radial direction. The tube-shaped cladding body is disposed on the pot-shaped base body surrounding the lateral wall. A groove is defined between the collar and the tube-shaped cladding body and the seal ring is disposed in the groove.

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

Abstract: A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.

Abstract: An impact mechanism device for a hand power tool comprises at least one impact mechanism including at least one driven cylinder and at least one piston driven in an axial direction by the at least one driven cylinder via a cam mechanism, and at least one planetary gearing configured to drive the at least one driven cylinder and the at least one piston. The at least one piston is positioned at least partially inside the at least one driven cylinder.

Abstract: In one embodiment, a reciprocating tool includes a first variable volume fluid chamber, a second variable volume fluid chamber in fluid communication with the first variable volume fluid chamber, a plunger configured to modify the volume of the first variable volume fluid chamber by movement generally in a first direction along a plunge axis such that a portion of a fluid moves from one of the first and second variable volume fluid chamber to the other of the first and second variable volume fluid chamber, a counterweight configured such that the movement of the portion of the fluid results in a movement of the counterweight generally in a second direction along the plunge axis, the second direction opposite to the first direction, and a chuck assembly supported by the plunger.

Abstract: A hammer drill comprises a motor including an output shaft, a shaft assembly rotationally engaged therewith, a hollow spindle, and a hammer mechanism comprising a piston arranged for reciprocating motion within the spindle. The shaft assembly comprises a first part carrying a first gear engaged with a gear on the spindle to cause spindle rotation, a second part carrying a crank member to cause piston reciprocation, and a connecting part configured to rotationally interconnect, or disconnect, the first and second parts. In a first position of the connecting part only one of the first and second parts is rotationally engaged with the output shaft to enable rotation of only one of the first gear and the crank member respectively, while in a second position both the first and second parts are rotationally engaged with the output shaft to enable rotation of both the first gear and the crank member.

Abstract: A hammer drill having a motor mounted within a body and an output spindle; a tool holder mounted on the body capable of holding a cutting tool; a hammer mechanism having a piston; a reciprocating drive for converting rotary movement of the motor into reciprocating movement of the piston; a ram reciprocatingly driven by the piston via an air spring to strike a cutting tool held in the tool holder, the hammer mechanism performing one hammer cycle each time the ram strikes a cutting tool during normal use; an air replenishment mechanism capable of refreshing the air spring during certain time periods during normal use; the air replenishment mechanism capable of being adjusted to refresh the air spring during time periods within the hammer cycle and/or the system allows different volumes of air into or out of the air spring during the refreshment time periods.

Abstract: A hammer drill including a cylinder; a piston and a ram mounted within the cylinder; a drive mechanism for converting rotation of a motor into reciprocating movement of the piston; a ram driven by the piston via an air spring; at least two air entry points formed through the wall of the cylinder in different axial positions along the length of the cylinder, each of which are capable of replenishing the air spring; the ram striking a tool in a tool holder; wherein there is further provided a selector mechanism which selectively opens and close the air entry points; characterized in that the selector mechanism opens only one air entry point at any one time during normal use, the selector mechanism closing all other air entry points, each of the air entry point capable of replenishing the air spring during normal use when opened by the selector mechanism.

Abstract: A controlled electro-pneumatic power tool includes an electro-mechanical adjustable valve, a pneumatic motor and a rotational speed sensor connected to a microcontroller for the selection, monitoring and adjustment adjustment of the rotational speed in real time. Using the communication port data for the consumable can be transmitted to the controlled electro-pneumatic power tool. The controlled electro-pneumatic power tool can read and utilize the transmitted data to select, adjust and maintain the optimum process parameters for the consumable without any input from the operator person. Furthermore, the communicated data can be used to warn the operator person that the tool used is inadequate for the selected consumable.

Abstract: An improved valve for a portable post driver. The post driver has an inner hollow cylinder open at both ends and adapted to receive a post through a lock clamp located at its lower end. An outer hollow cylinder having a closed upper end, and slightly larger in diameter than the inner cylinder, is located in sliding engagement over the inner cylinder. First and second power cylinders are attached to upper and lower surfaces of the outer cylinder in alignment with each other. A common piston rod connects the pistons of the power cylinders. A stationary fastening pin attached to the piston rod extends through a slot in the wall of the outer cylinder and is attached to the wall of the inner cylinder. The valve has a reciprocating valve piston which alternately communicates the two power cylinders to a source of fluid under pressure.

Abstract: A percussion apparatus driven by a pressurized incompressible fluid includes a body with two coaxial bores for slidably mounting of a tool, and separately slidably mounting a striking piston having a stepped configuration. A control device varies a stroke of the striking piston between a long and a short stroke, and is connected to the directional flow valve and to a bottom chamber of the piston cylinder. The control device includes a cylinder in which a spool is mounted. A first face of the spool is situated in a first chamber permanently subjected to a determined pressure, and a second face of the spool is situated in a second chamber connected to the braking chamber for controlling the varying of the stroke of the striking piston.

Abstract: A hydraulic rock breaking device, a protection valve and a method of operating a hydraulic rock breaking device. The rock breaking device comprises a percussion device to which pressure fluid is fed along an inlet channel. The inlet channel is provided with a protection valve arranged to monitor the volume flow of pressure fluid flowing through it. If the flow is larger than what has been preset, the protection valve closes, at least partly, the connection through it, protecting thus the percussion device against too high an input power. The protection valve comprises a throttle which generates a pressure difference the magnitude of which is dependent on the fed volume flow. Information on the pressure difference is utilized in controlling the protection valve.

Abstract: A pneumatic device control apparatus and method comprising a ported valve slidably fitted over a feed tube of the pneumatic device, and using a compliant biasing device to constrain motion of the valve to provide asymmetric timing for extended pressurization of a power chamber and reduced pressurization of a return chamber of the pneumatic device. The pneumatic device can be a pneumatic hammer drill.

Abstract: A fluid distributor cylinder is for a percussive drill assembly that includes a casing having an inner circumferential surface defining a central bore, a central axis extending through the bore, a bit movably coupled with the casing and a piston movably disposed within the casing bore. The distributor cylinder includes a generally tubular body disposeable within the casing bore and having first and second ends, a central axis extending generally between the first and second ends, an outer circumferential surface. At least a section of the outer surface is configured to engage with the inner surface of the casing so to form an interference fit between the body and the casing. The cylinder includes an exterior thread and/or a radially-extending shoulder configured to releasably engage with the casing inner surface so as to substantially prevent axial displacement of the distributor body with respect to the casing.

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: Disclosed herein is a pneumatic operated hammer for rock drilling, the hammer comprising a cylindrical casing, a back head mounted at an upper portion of the casing, a check valve for opening/closing a compressed air passageway in the casing, a guide for supporting the check valve, a piston adapted to ascend and descend with compressed air in the casing, and a button bit for performing a drilling work through the striking of the piston. The piston is extended to a certain length to conform to the work condition of the pneumatic hammer to thereby prevent a water back-flow phenomenon in which underground water, etc.

Abstract: The invention of this application provides a pneumatic tool with a simple structure. The tool has a tubular housing, a stationary shaft, a first piston slidable along the stationary shaft, a second piston, a tool attachment member drivingly connected to the second piston, a compressed air supply path extending through the stationary shaft to supply compressed air between the first and second pistons, and an air discharge path for discharging the compressed air supplied between the first and second pistons to the outside of the housing when the first and second pistons are separated by a predetermined distance. The compressed air supply path has an axial portion in the stationary shaft and a radial portion, a compressed air inlet recess in the inner wall surface of a shaft sliding hole, and a supply outlet extending forward from the forward end of the compressed air inlet recess and communicating with a portion between the first and second pistons.

Abstract: The invention of this application provides a pneumatic tool with a simple structure. The tool has a tubular housing (50), a stationary shaft (52), a first piston (56) slidable along the stationary shaft, a second piston (58), a tool attachment member (60) drivingly connected to the second piston, a compressed air supply path (70) extending through the stationary shaft to supply compressed air between the first and second pistons, and an air discharge path (76) for discharging the compressed air supplied between the first and second pistons to the outside of the housing when the first and second pistons are separated by a predetermined distance. The compressed air supply path has an axial portion (70a) in the stationary shaft and a radial portion (70b), a compressed air inlet recess (70c) in the inner wall surface of a shaft sliding hole, and a supply outlet (70d) extending forward from the forward end of the compressed air inlet recess and communicating with a portion between the first and second pistons.

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: The invention discloses a fluid-driven impactor, a power transmission mechanism for the impactor and the use of the impactor. In the prior art, the working life of the impactor is short, since a rubber primary seal and an upper fluid-diverging lid for the fluid-driven impactor are both liable to erosion and the efficiency in transmitting power is low due to the complexity of the power transmission mechanism. In order to increase the drilling speed and/or extend the life of the impactor, the side cavity passage is formed in such a way that the inner wall of the outer pipe is isolated from the side cavity passage in a watertight manner without the use of the rubber primary seal. The loss in transmitting power is minimized by integrating the anvil of the power transmission mechanism and the lower joint.

Abstract: A hydraulic hammer having a sealing bushing includes a percussion piston that delivers strokes to a tool. A lower part of the percussion piston is sealed with respect to a frame by the sealing bushing, which includes one or more lower seals. The sealing bushing does not contribute to the bearing of the percussion piston and it is arranged in place through the lower end of the hydraulic hammer.

Abstract: The percussion device which can be used as a hammer drill has a drive piston for driving an overhung percussion piston which is mounted between two air cushions. Depending on the percussion travel of the percussion piston, the percussion air cushion is reversed so that a respective partial quantity is passed around the percussion piston to the opposite side by a central bypass. A no-load bypass is also provided to vent the recoil air cushion to the percussion cushion for a no-load condition. A third bypass bridges the drive piston in the top dead center position to communicate an annular chamber to the rear of the drive piston with the percussion cushion.

Abstract: A power hammer drill includes a tool holder and an air cushion striking mechanism for driving a tool and including a striker, a reciprocating piston for displacing the striker, and an axially displaceable guide tube for guiding the piston. A device for holding the striker in a forward position thereof adjacent to the tool holder in an idling condition of the hammer drill is provided in the hammer drill. The device has a guide element fixed in the drill housing for guiding the guide tube. The guide tube has a control opening for venting the air cushion and which remains in open or closed condition dependent on axial position of the guide tube.

Abstract: A pneumatic percussion tool for rock breaking and other purposes having removably enclosed within an outer casing a pneumatic engine including a cylinder with a work head extending slidably from its lower end, a piston slidable in the cylinder impacting the work head on its downstroke. The piston serves also as a sliding valve into which compressed air is admitted through an air inlet tube fixed coaxially in the cylinder and on which the piston is slidable. The piston and cylinder are formed with such air ports and passages that the engine remains at rest until the work head applied with pressure to a work-piece is retracted into the cylinder displacing the piston valve which thereupon is reciprocated, causing the work head to deliver percussive blows while applied to the work-piece. At the final part of its upstroke, the piston enters a compression chamber or energy cell which thus decelerates the piston and commences its downstroke.

Abstract: A vacuum-compression type percussion power tool comprises a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside cylinder (14) in a space between a tail portion (26) of working tool (24) and the lower end of the piston. The power tool has a sealed auxiliary chamber (54, 56) , which is formed by a hollow casing (48) which surrounds the cylinder, and a space below striker (34). The auxiliary chamber is connected to a main working chamber (38), which is formed between the piston and the striker, through a set of compensation holes (44) and a set of idle-stroke holes (46). The power tool has a pumping chamber (27) which is formed in the upper part of cylinder (14) between the upper end face of piston (16) and a closed cover (17).

Abstract: A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside the cylinder (14) in a space between a tail portion (26) of the working tool (24) and the lower end of the piston.

Abstract: A vacuum-compression type percussion power tool comprising a housing (12), a cylinder (14) fixed in the housing, a piston (16) reciprocating in the cylinder (14) from a reciprocating drive mechanism such as a crank mechanism (18) driven by an electric motor, or any other suitable drive, a working tool (24) installed in the front part of the power tool, and a floating striker (34) which slides inside the cylinder (14) in a space between a tail portion (26) of working tool (24) and the lower end of the piston. The power tool has a sealed auxiliary chamber (54, 56) which is formed by means of a hollow casing (48) which surrounds the cylinder, and a space below the striker (34). The auxiliary chamber is connected to a main working chamber (38), which is formed between the piston and a striker, through a set of compensation holes (44) and a set of idle-stroke holes (46). A check valve (51) is installed in the wall of the auxiliary chamber.

Abstract: In a hammer drill, a striking mechanism supplied percussive force to a tool. The striking mechanism includes a free piston slidably displaceable in a reciprocating manner within a guide cylinder. Balls mounted in the guide cylinder are spring biased into a recess in the free piston for securing the piston in a locked position so that it cannot deliver percussive force to the tool. The balls are spring biased by a ring encircling the cylinder with a spring pressing the ring in the axial direction of the cylinder against the balls.

Abstract: A percussive tool comprises a percussion mechanism and a pressure pulser. The percussion mechanism has a hollow housing with a piston hammer arranged thereinside to form two chambers of variable volume. The pressure pulser has a hollow housing and a fluid displacer defining inside the housing a working chamber adapted to alternately communicate with a source of gaseous fluid and the interior of the percussion mechanism. The fluid displacer is intended for forced displacement inside the housing to transmit to the chambers of the percussion mechanism a pulsed pressure of the gaseous fluid which causes the piston hammer to reciprocate. The interior of the percussion mechanism is isolated from the outside, whereas the working chamber of the pressure pulser communicates with at least one of the chambers of the percussion mechanism, the chambers of the percussion mechanism continuously intercommunicating by way of a restrictor passage.

Abstract: A vibration or reciprocating hydraulically driven impact tool for breaking up paving, compacting soil, or similar construction purposes. The tool employs a piston situated in a housing and configured to form (in cooperation with the housing) three chambers. One of the chambers is filled with a compressed gas which acts as a shock absorber/spring, with the other two chambers serving to drive adjacent flanges of the piston in opposite directions to provide reciprocating action. The device is constructed so that when no mechanical force is applied to the handle, the piston is at rest in its forward position (being urged there by the compressed gas), with the hydraulic forces acting upon the piston shoulders being balanced. When the handle is pushed forward, the hydralic system is altered so that unbalanced forces act on the piston flanges, causing the piston to start moving. Thereafter, a hydraulic valve system provides the desired reciprocating motion of the piston.

Abstract: Disclosed herein is a percussive tool having a piston and a ram slidably mounted within a cylinder which is axially displaceable. An air chamber is defined in front of the ram, and the cylinder has exhaust openings formed therein. With the cylinder in its retracted position, the exhaust openings communicate with the front air chamber so that the air cushion therein is vented during forward movement of the ram, and with the cylinder in its advanced position, the exhaust openings are closed to seal the air chamber so that the ram is limited in its rearward movements.

Abstract: In a hammer drill, a drive piston is reciprocated by a motor, and, over a pneumatic buffer, the reciprocating motion is transmitted to a percussion piston. A throttle valve regulates the flow of a fuel mixture to the motor for controlling its operation. A membrane switch connected to and operated by the pressure conditions within the pneumatic buffer controls the throttle valve.

Abstract: In an electropneumatic hammer including an exciter piston and a percussion piston reciprocally displaceable within the bore of a guide cylinder, a sleeve-like clamping member is secured in an axially stationary position within the bore of the guide cylinder with the percussion piston passing through the clamping member. If there is no tool in the hammer and under certain other operating conditions, an axially displaceable tubular member located within the bore and laterally enclosing the clamping member, presses the clamping member inwardly into gripping contact with the percussion piston.

Abstract: A hammer mechanism is disclosed, which incorporates a hammer piston driven by a driving piston via a pressure-gas cushion in a working chamber. The hammer piston controls the transference of flushing gas from the working chamber to the tool during normal operation and has an extreme position in which the hammer piston does not interfere with the transference of flushing gas.