Abstract: An impact device includes a frame to which a tool is connectible, and a stress element that is supported on the frame and disposed between the frame and the tool. A hydraulic control system leads pressurized hydraulic fluid into and out of a hydraulic fluid space such that the stress element causes a stress pulse in the tool. The hydraulic control system includes a rotatingly installed control valve that has control openings for intermittently leading the hydraulic fluid out from the hydraulic fluid space.

Abstract: A percussion device for a rock drilling machine or the like, which comprises means for providing an impact, i.e. a stress pulse, to a tool connected to the percussion device. The means for proving the stress pulse include a stress element (4) of liquid, which is supported to a body (2) of the percussion device and means for subjecting the stress element to pressure and correspondingly for releasing the stress element (4) 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 wholly air-controlled impact mechanism invented for creating a more compact and powerful pneumatic wrench comprises a flying hammer, a pressure impulse generator and a pressure container containing the hammer and the generator. The main part of the flying hammer is a flywheel with 2 cavities and a number of air passages. A pilot valve and an impact pin are fitted in the cavities. The impact pin rests in its cavity during energy-accumulation phase and stretches out rapidly from the flywheel to finish an impact during impact phase. The generator transmits pressure impulse periodically, affecting the differential pressure acting on the pilot valve. The higher the differential pressure, the greater the impact torque developed. The unique design of the air passages of present invention results in a very reliable, powerful and durable energy-accumulating pneumatic wrench. Its production cost is much lower due to simplicity of its configuration.

Abstract: An impact tool has a slidable hammer that is driven by hydraulic oil under pressure inside a chamber. The hydraulic oil is pressurized by a piston driven by compressed gas on the opposite side of the piston from the hydraulic oil. The gas in the gas chamber is compressed by the piston on an initial stroke, and has a large annular chamber holding the gas so that higher average gas pressure can be attained during the power stroke. As the piston is moved to compress the gas, the piston lifts a valve that opens a passage for the hydraulic oil moved by the piston to act on a hammer to impact a breaking tool. The piston is a two part piston that serves to lower the inertia during the final closing of the valve, and thereby reduces impact loads on the valve as it is closed. The valve also is controlled as to its stroke for efficient operation.

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: A crushing hammer, and a fastening element, side plate, and protective casing for the crushing hammer. The crushing hammer comprises at least two alternative fastening elements with which it can be fastened to a boom of a work machine. The fastening can be done with a separate fastening element that is equipped with a plane surface for flange mounting and openings for a pin mounting. The fastening elements may also be formed to side plates, between which the crushing hammer is arranged. The fastening elements may further be integrated to the protective casing.

Abstract: A method of expanding tubing comprises the steps: providing a length of expandable tubing; locating an expansion tool, such as a cone, in the tubing; and applying impulses to the tool to drive the tool through the tubing and expand the tubing to a larger diameter. The tubing may be located downhole and may have a solid wall or a slotted wall.

Abstract: An impactor for use with a directional boring machine for replacement of underground pipes includes a bursting head having a rearwardly opening recess and a front end opening that communicates with the recess. An inlet pipe is connected at its front end to a distal end of the drill string and extends into the recess of the bursting head through the front end opening. A striker is mounted for sliding movement along the inlet pipe, and a distributing mechanism responsive to pressure fluid supplied through the drill string and inlet pipe causes the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the bursting head. The striker and distributing mechanism are mounted in a tubular housing, and a pulling connection is provided by which the impactor can be pulled by the drill string while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the drill string.

Abstract: A percussion apparatus and method of using the percussion apparatus. The apparatus may be used for delivering an impact to a tubular string. The apparatus comprises a cylindrical member having an internal bore containing an anvil and a first guide profile. The apparatus further includes a rotor disposed within the internal bore, and wherein the rotor member comprises a body having an outer circumference with a second guide profile thereon, and wherein the rotor contains a radial hammer face. In a first position, the second external guide profile of the rotor will engage with the first guide profile of the cylindrical member so that the radial hammer face can contact the anvil. In a second position, the second guide profile of the rotor will engage with the first guide profile of the cylindrical member so that the radial hammer face is separated from the anvil shoulder. Multiple rotors and multiple stators may be employed. The rotor may be operatively associated with a stator that directs flow into the rotor.

Abstract: An electrically powered hammer comprising a hollow spindle within which spindle is reciprocatingly mounted a piston, a ram, a beatpiece having an increased external diameter mid-portion and located within the spindle between the ram and the tool or bit, a two part sleeve arrangement located within the spindle and including an increased internal diameter mid-portion for receiving the increased external diameter portion of the beatpiece and a reduced internal diameter forward and rearward portion for guiding the forward and rearward ends respectively of the beatpiece and where the sleeve arrangement includes a forward sleeve and a rearward sleeve which are both guided with tight radial tolerances and with a slight axial play within and by the spindle and the forward axial movement of the forward sleeve is limited by a reduced diameter portion of the spindle and the forward axial movement of the rearward sleeve is limited by the forward sleeve.

Abstract: The invention relates to a pneumatic percussive tool for a paving breaker and/or a hammer drill comprising a drive piston which is displaceable both backwards and forwards by a crankshaft and arranged in a percussion piston which is displaceable both backwards and forwards. A hollow chamber is connected to a compensating chamber by an idling air channel and embodied between the drive piston and the percussion piston in order to receive a pneumatic spring. A valve is arranged in the idling air channel, the opening and closing position thereof depending on the rotational speed of the crankshaft. If the rotational speed of the crankshaft falls below a predetermined value, the valve opens the connection between the hollow chamber and the compensating chamber so that a pneumatic spring can no longer be to embodied in the hollow chamber and the pneumatic percussion tool is placed in a idling position.

Abstract: An electrical hand held tool for producing at least a percussion movement of a working tool includes an electrical drive, a first, oscillating subassembly including a percussion mechanism (2) and a rotor (5) of the electrical drive for transmitting torque to the percussion mechanism and rotatable about a rotor axis (B) extending parallel to an oscillation path (I) of the first subassembly, and a second subassembly including a housing (6) in which the first subassembly is supported for a limited oscillating movement along a tool axis (A).

Abstract: A post driving implement for use with a vehicle, such as a tractor or a skid loader, is disclosed. The post driving implement is comprised of a hammer, a hammer channel, and a hammer cylinder. The hammer travels longitudinally within the hammer channel and is lifted by the hammer cylinder mounted to a closed end of the hammer channel. The hammer cylinder and its associated plumbing is of sufficient size to function as a hydraulic reservoir for the post driving implement, thus eliminating the need for a third hydraulic line to the reservoir on the vehicle and to avoiding need for alteration of the vehicle's reservoir. The post driving implement of the present invention may also include a back plate for mounting the implement to a vehicle. Additionally, the post driving implement may include adjustment mechanisms to vary the positional and angular relationship between the vehicle and the implement.

Abstract: A pipe breaking assembly is shown with a modular design that allows a user to more economically purchase a single base unit that is adaptable using a number of elements. Combinations of elements such as blade portions and expander cones, etc. allow the modular assembly to be tailored to a variety of job conditions. A pipe breaking assembly is shown that includes a particular configuration where a blade portion is located in front of a shortened expander cone. The shortened expander cone provides a lower contact area that in turn reduces friction.

Abstract: An impactor for use with a directional boring machine for replacement of underground pipes includes a bursting head having a rearwardly opening recess and a front end opening that communicates with the recess. An inlet pipe is connected at its front end to a distal end of the drill string and extends into the recess of the bursting head through the front end opening. A striker is mounted for sliding movement along the inlet pipe, and a distributing mechanism responsive to pressure fluid supplied through the drill string and inlet pipe causes the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the bursting head. The striker and distributing mechanism are mounted in a tubular housing, and a pulling connection is provided by which the impactor can be pulled by the drill string while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the drill string.

Abstract: The invention is based on a hand power tool, in particular a drilling- and/or chipping hammer, having a machine housing (12), a tool guiding element (16; 54), a hammer tube (14; 52), and a safety catch (32)—fixed in the housing in stationary fashion in the axial direction—for a striker (24) that can be driven by means of a drive piston (22) and that is actively joined with a tool (20) situated in a tool guiding element (16; 54). It is proposed that the tool guiding element (16; 54) is designed to be axially displaceable in relation to the machine housing (12).

Abstract: An impactor for use with a directional boring machine for replacement of underground pipes includes a bursting head having a rearwardly opening recess and a front end opening that communicates with the recess. An inlet pipe is connected at its front end to a distal end of the drill string and extends into the recess of the bursting head through the front end opening. A striker is mounted for sliding movement along the inlet pipe, and a distributing mechanism responsive to pressure fluid supplied through the drill string and inlet pipe causes the striker to reciprocate in the rearwardly opening recess of the head to deliver forward impacts against the bursting head. The striker and distributing mechanism are mounted in a tubular housing, and a pulling connection is provided by which the impactor can be pulled by the drill string while the striker is delivering impacts against the head in the same direction as a pulling force exerted by the drill string.

Abstract: An electrically powered hammer comprising a hollow spindle within which spindle is reciprocatingly mounted a piston, a ram, a beatpiece having an increased external diameter mid-portion and located within the spindle between the ram and the tool or bit, a two part sleeve arrangement located within the spindle and including an increased internal diameter mid-portion for receiving the increased external diameter portion of the beatpiece and a reduced internal diameter forward and rearward portion for guiding the forward and rearward ends respectively of the beatpiece and where the sleeve arrangement includes a forward sleeve and a rearward sleeve which are both guided with tight radial tolerances and with a slight axial play within and by the spindle and the forward axial movement of the forward sleeve is limited by a reduced diameter portion of the spindle and the forward axial movement of the rearward sleeve is limited by the forward sleeve.

Abstract: A hand-held power tool for use in hand working operations including a hand pressure sensing element for adjusting the power of the tool. More specifically, the invention provides a hand engraving power tool that is activated from absence of power to much greater power or anywhere in between determined by the amount of pressure exerted by a human hand on the tool's handle.

Abstract: A rotary hammer includes a spindle 18 which can be rotatably driven by an intermediate shaft 24 by way of a drive device. A tool holder 16 is arranged for rotation with the spindle 18, and for releasably holding a bit or tool for selective rotation and/or reciprocation. A pneumatic hammering arrangement facilitates repeated impacting of the bit or tool for reciprocation within the tool holder (16). A mode change mechanism includes a knob 18 for selectively operating the rotary hammer in any of three modes, identified as a rotary drive only mode, a hammer only mode and a rotary hammer mode.

Abstract: A hand held portable multipurpose demolition tool is powered by bottled compressed gas operating a pneumatic impact mechanism with interchangeable tools. The compressed gas, gas supply pressure and gas flow rate are variable allowing application of the tool to a large variety of demolition, construction, forcible entry, and ancillary functions.

Abstract: A fastener driving tool is disclosed having a self contained pre-pressurized pneumatic power source. Operator actuation of a trigger mechanism causes a pressurized medium supplied by the self contained pre-pressurized power source to flow through a valve and to propel a piston connected to a driver blade towards a nosepiece assembly end of the tool. The flow of the pressurized medium through the valve further recoils a spring-biased activating bolt which resets the trigger mechanism.

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

Abstract: A hand-held pneumatic impact tool for use in fine hand working operations includes a mechanism for adjusting impacting characteristics of the device that is conveniently located and adjusted by the user. The mechanism includes an annular band protruding around the outside diameter of the body of the impact tool that may be turned for adjusting the piston stroke length and speed at which impacts occur.

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

Abstract: A breaker, used for breaking target hard objects, such as reinforced concrete structures, rocks or hard soil, using pneumatic and hydraulic pressure, is disclosed. In the breaker, the piston is multi-stepped to form first, second and third oil chambers between the piston and the cylinder. First, second, third and fourth oil paths are formed in the sidewall of the cylinder. The first oil path extends from the oil inlet port to the first chamber, thus feeding pressurized oil from an external oil source to the first chamber. A valve chamber is formed in the sidewall of the cylinder. The second oil path allows the valve chamber to selectively communicate with the second chamber. A directional control valve unit is installed within the valve chamber, and selectively returns the pressurized oil from the first chamber to the valve chamber prior to feeding the oil from the valve chamber to the second chamber through a plurality of oil ports and the second oil path.

Abstract: An electrical hand-held tool for producing at least a percussion movement of a working tool and including an electrical drive, a first subassembly including a percussion mechanism (2) and a rotor (5) of the electrical drive and rotatable about a rotor axis (B) extending parallel to an oscillation path (I) of the first subassembly, and a second subassembly including a housing (6) in which the first subassembly is supported for a limited movement along a tool axis (A).

Abstract: A hydraulic hammer having an improved seal ring contacting with a piston. The hydraulic hammer having a cylinder having an inner surface where a fluid groove connected to a passage for passing the fluid is formed, a piston installed in the cylinder to be elevated, and a first seal ring for guiding the elevation of the piston, installed in an inner surface of the cylinder under the fluid groove and contacting with the piston, includes one or more second seal rings having one or more grooves or holes for passing the fluid, installed on the fluid groove and/or between the fluid groove and the first seal ring. Accordingly, the length of use before replacement of the seal ring installed between the piston and the cylinder can be extended, to thereby reduce the cost for operating the hydraulic hammer.

Abstract: A hand-held pneumatic impact tool and method of controlling the same for use in fine hand working operations includes a handpiece, a foot-operated flow control valve and a hand operated flow control needle valve. The handpiece includes a housing having a cavity and annular shoulder accommodating a stepped piston dividing the cavity into three chambers. The design provides a means to oscillate a piston without delivering impacts and to oscillate the piston with varying amounts of impact energy.

Abstract: There is provided a power-driven striking tool including: a casing; a tool holder rotatably supported inside the casing and having a front end to which a tool bit is attached; and an operating member fitted around the tool holder and exposed to the outside of the tool so as to be manually slidable in the axial directions of the tool holder and integrally rotatable with the tool holder. The operating member is biased rearward by a compression spring along the axis of the tool holder into contact with the casing. The tool further includes first teeth provided on the operating member where it comes into contact with the casing and second teeth provided on the casing where it comes into contact with the operating member. When the operating member is brought into contact with the casing, the first and second teeth engages each other to prevent the operating member and thus the tool holder from rotating relative to the casing.

Abstract: A percussion tool, such as a drill or a chisel tool, including a percussion mechanism (7), a tool chuck (1), and a damping member (8) arranged between the tool chuck (1) and the percussion mechanism (7) for damping rebounds of a header (9) axially displaceable in the tool chuck (1), with the damping member (8) having, arranged one after another in the operational direction, a stop disc (86), an elastic ring (83), and a transmission element (81) having a cavity for receiving both the stop disc (86) an the elastic ring (86).

Abstract: An engine-driven breaker which is capable of providing a breaking force equal to that of a hydraulic or pneumatic breaker even with a small engine and which is small and light and easy to handle and has a simple construction enabling it to be manufactured cheaply. The engine-driven breaker has a breaker main body and a cylinder fixed inside the breaker main body and inside the cylinder an upper air chamber of variable volume is provided between an operating piston and a hammer piston and a lower air chamber of variable volume is provided below the hammer piston.

Abstract: An airflow regulation arrangement for regulating the impact of the strikes delivered from a striking member (6) to an intermediate member (10) and a bit, thus reducing the vibration, and also for regulating the impact of recoils of the striking member (6) is disclosed for use in an electrical hammer (1). The airflow regulation arrangement comprises an air inlet (14) provided in an air chamber (5) in a cylinder (3) of the electrical hammer (1), exhaust ports (15) provided in a second air chamber (9), and air passages (16) in communication with the air inlet (14) and the exhaust ports (15). The air passages (16) are connected to choke passages (17), the cross sectional area of which is one fifth to one sixth of that of the air passages (16).

Abstract: An improved pile driving drop hammer of the free piston internal combustion engine type preferably has integral pistons on each end of a ram that reciprocates, usually vertically, in an enclosing bore. There is a combustion chamber on each end of the bore and exhaust ports situated near each combustion chamber such that the ports are opened, two cycle engine fashion, by the associated piston, after some movement of the piston, after combustion takes place to vent the active combustion chamber and then serve as intake ports when the piston moves some distance farther along the bore. At each end of the bore an anvil extends from the bore, axially movable some amount, to serve as an end to each combustion chamber. The lower anvil delivers ram impact energy to the driven piling and the upper anvil delivers impact energy from the ram to a free rising mass that is the essential element of this invention as an improvement to existing hammer designs.

Abstract: A handheld pneumatic power tool apparatus is provided for use with a supply of pressurized air. The apparatus includes a handpiece and a pressure regulator assembly for regulating the pressure of air supplied to the handpiece. The handpiece includes a cylinder having first and second ends, an anvil positioned at the first end of the cylinder, and a piston received in the cylinder for bi-directional oscillating movement between the ends.

Abstract: A transportable drop hammer for impacting a ground surface adapted to be removably coupled to a driven host transport apparatus having lifting arms. An upstanding frame is couplable to the host transport apparatus and is provided as having a stabilizing foot portion attached to the frame for contacting the ground surface. A mast is mast attached to the frame and is disposed substantially vertical to the ground surface. A weight assembly, having a ground confronting face portion and at least one bearing surface engaging the mast, is operable between a ground position impacting the ground surface and a drop position. For selectively raising the weight assembly to a predetermined drop position, a manually controlled lifting apparatus is provided which actuable to release the weight assembly for its substantial free fall from the drop position to the ground position.

Abstract: A tie rod loosening tool for use with a tie rod assembly, the tie rod assembly having an outer tie rod, an inner tie rod and a threaded adjustment sleeve extending from the inner tie rod and being received within the outer tie rod. An elongated tool member is provided upon removal of a standard threaded bolt which secures the outer tie rod to the adjustment sleeve during normal operation The tool member has a first externally threaded end for threadably engaging within an aperture in the outer tie rod. The elongated tool member has a second end which defines a tool bit which may be received within a power tool. The power tool is activated to forcibly loosen, by vibration or jarring, the inner and outer tie rods from the threaded adjustment sleeve and overcomes corrosive buildup between the tie rods and the adjustment sleeve.

Abstract: An impact device for breaking up and separating hard material comprises an actuating system for providing a faster cycle rate as well as an increased impact force. More specifically, the device includes a pair of pistons movably arranged in a cylinder to cooperate in compressing the gaseous component prior to initiating the blow. A closed tube is provided to fluidly interconnect opposite chambers adjacent the two pistons to coordinate the different movements of the pistons to effect the desired compression. The impact device is particularly well suited for use in an impact bucket.

Abstract: An impact power tool for use in supporting a tool tip for hand-working operations comprises a body presenting a bore and having first and second ends. A piston is received within the bore and is shiftable relative to the body, and an anvil is received within the bore at a first end of the body and is shiftable relative to the body along the longitudinal axis thereof. The anvil includes a recess extending in a direction substantially parallel with the axis of the bore so as to define a receptacle in the anvil adjacent the first end of the bore. A tool carrier block is provided which is shaped for receipt in the recess of the anvil and which includes a set screw for permitting attachment of the carrier block to a tool tip to be supported on the impact power tool. The carrier block is retained in the anvil by friction-fit engagement sufficient to retain the carrier block in the receptacle and to permit manual removal of the carrier block.

Abstract: A hydraulically operated striking mechanism includes a contact pressure control member held at least temporarily in contact with an insertion end of a drilling tool by a mechanism which applies a restoring force in the striking direction. A control conduit is connected by way of the contact pressure control member either to a pressure conduit or to a pressure return conduit. The control conduit actuates a switching element so that a control unit which alternatingly switches the movement of the striking piston performs a reversal movement into an operating stroke position at an earlier or later point in time during the return stroke of the striking piston and thus actuates the operating stroke of the striking piston in the striking direction.

Abstract: A hydraulically operated hammer drill includes a housing in which a striking piston is displaceably disposed for alternating movement. The striking piston is driven in striking and return directions by a first operating pressure. A rotatable, tool receiving device is connected to the housing for receiving an insertion end of a drilling tool and permitting displacement of the insertion end in the longitudinal direction when charged by the striking piston. A rotation drive mechanism, driven by a second operating pressure, is mounted for rotatably driving the tool receiving device during longitudinal displacement of the insertion end. A control unit is disposed along a pressure conduit supplying the first operating pressure for alternatingly switching the direction of movement of the striking piston by controlling application of the driving medium to control faces of the striking piston.

Abstract: An impact tool includes a body, a barrel mounted on the body and a cylinder disposed within the barrel and reciprocally moved by a drive mechanism. A communication groove is formed between the cylinder and the barrel and communicates with the outside. The cylinder includes a plurality of communication holes formed in a radial direction and spaced from each other in a longitudinal direction. A striker is reciprocally movable within the cylinder, and an air chamber is formed between the striker and the cylinder. The striker is positioned at a first position when the tool bit is not pressed on a work. The striker at the first position permits communication between the air chamber and the communication groove through any one of the communication holes so as to be prevented from idle impact. Further, the striker is movable to a second position rearward of the first position through the pressing operation of the tool bit on the work.

Abstract: A percussive machine comprises a housing (10) with a cylinder (11) therein, in which a reciprocating drive piston (40) via a gas cushion in a working chamber (44) repeatedly drives a hammer piston (15) to impact on the neck (17) of a tool (20) carried by the housing (10). At empty blows with the neck (17) out of reach, the hammer piston (15) is thrown forwardly and caught pneumatically in a braking chamber (47) at the bottom end (12) of the cylinder (11). The braking is combined with an elastic yielding of the bottom end (12) against the action of a recoil spring (23) in the housing (10). The pressure in the braking chamber (47) during such yielding is controlled by throttling apertures (48) in the cylinder (11) uncovered by the bottom end (12). The hammer piston (15) is thus checked to halt pneumatically by throttling avoiding a collision with the bottom end (12) and takes an inactive position below ports (46) in the cylinder wall through which the working chamber (44) is relieved and ventilated.