Abstract: An electric power tool, in particular an electric hammer, having a drive unit (11) contained in a housing (10), an impact mechanism (12), and a handle (13), including a cam (14) that is driven by the drive unit (11); the impact mechanism (12) has moving parts (15, 16). At least two of the moving parts (15, 16) are able to move inside a separate guide cylinder (17) that is stationary in relation to the moving parts (15, 16) and the cam (14).

Abstract: Floating pistons are implemented in hydraulic rock drilling hammer, or hydraulic hammer breaker, or fluid DTH hammer. The chambers confined by the impact piston and the body case are connected via ports and the floating pistons. The pistons balance the pressure difference when pressure pulsation happens in the chambers during the reciprocating movement of impact piston. It dampens the pulsation, prevents cavitations and assists the forwarding and returning movement of impact piston. The device will also be potential to increase the efficiency and impact power of hammers.

Abstract: The invention relates to a device and to a method for producing pressure waves of a high intensity. Thereby, a flowable, explosive substance, or flowable components which form an explosive mixture on mixing and are preferably gaseous, are introduced into a pressure-tight container and ignited. The gas pressure arising from the ignition is led away through a previously closed passage. Preferably, a closure is kept closed by way of a spring element until the explosion, wherein the spring element comprises a relief device.

Abstract: An hydraulic attachment (10) adapted to be mounted to machinery or a vehicle such as a skid-steer loader (35) and having a telescopic mast assembly (11) including a first lower mast member (12) and at least one second upper mast member (13) telescopically engaged with the lower mast member (12) and at least one hydraulic actuator (15) for extending or retracting the upper mast member (13) relative to the lower mast member (12). Mounting means (34) are provided for mounting the mast assembly (11) to the loader (35) so as to be supported in use in a substantially upstanding attitude and the mast assembly (12) includes support means (22) at its upper end for supporting or carrying a tool such as an impact applying tool (23).

Abstract: A hydraulic impact mechanism includes a housing with a cylinder bore, a forward working chamber and a rear working chamber, a hydraulic fluid supply passage connected to the forward working chamber and a drain passage connected to the rear working chamber, a hammer piston reciprocally guided in the cylinder bore for delivering blows to a working implement attached to the housing, a pressure accumulator pre-loaded to a certain pressure level, and a distribution valve for alternatingly connecting the rear working chamber to the supply passage and the drain passage to thereby reciprocate the hammer piston, wherein a sequence valve is provided in the drain passage to keep up the pressure in the rear working chamber so that the resulting forward directed force prevents the piston from being moved backwards in the cylinder bore at pressure levels in the supply passage below the pre-load pressure level of the accumulator.

Abstract: A drive system for driving and/or extracting an elongate member. The drive system comprises a piston drive assembly, a hydraulic system, and a vibration drive assembly. The piston drive assembly comprises a piston member, and the piston member engages the elongate member. The hydraulic system is operatively connected to the piston drive assembly to apply a drive force to the piston member. The vibration drive assembly generates a vibratory force. The vibration drive assembly is operatively connected to the piston drive assembly. The drive system operates in a first mode in which the drive force and the vibratory force are applied to the piston member along a drive axis.

Abstract: The invention relates to a tool (1), in particular an impact wrench, with a pulse unit (6) having a hydraulic impact mechanism (7) and a drive unit (24). The working volume (5) can be connected within the hydraulic impact mechanism (7) to an additional volume (5) formed outside of the said mechanism. The tool according to the invention is characterised in that at least the compensating volume (4) can be varied independently of the pressure.

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.

Abstract: A pneumatic tool (20) for impacting a workpiece (22) is provided. The tool (20) comprises a casing (42) defining a chamber (48). A piston (54) is slidable within the chamber (48) along an operational axis (A). An exhaust valve (100) controlled by a pilot valve (200) slides the piston (54) by selectively introducing and releasing pressurized fluid into and out from the chamber (48). The pilot valve (200) includes a valve housing (202) defining a pilot chamber (204) with a plunger (206) slidable in the pilot chamber (204). The pilot valve (200) actuates the tool (20) by quickly releasing pressurized fluid from the exhaust valve (100) to atmosphere. The pilot valve (200) includes a spring-biased annular seal (214) that is releasable from a poppet seat (222) to perform this function.

Abstract: A scaling apparatus comprises a hammer component and a pick component which includes a tooth. The apparatus also includes a mechanism for moving the pick component with respect to the hammer component to thereby impart a scaling force to and through the tooth. In a preferred embodiment of the invention, the pick component includes a pick body comprising a first pivot having a pivot axis and a tooth mounted on the pick body. In this embodiment of the invention, the hammer component includes a hammer housing and a second pivot mounted within the housing and adapted to pivotally engage the first pivot of the pick body. This embodiment of the invention also includes a mechanism for rotating the pick body relative to the hammer component so as to impart a scaling force.

Abstract: A driver blade for use in a combustion-powered fastener-driving tool includes an elongate tubular body having a combustion end and a driving end, the combustion end being configured for attachment to a piston, and the driving end having a substantially solid cross-section. The tubular body is in fluid communication with a tool combustion chamber.

Abstract: An impact driver capable of boring and having an excellent usability is provided. An anvil(8) is arranged so as to slightly move in the axial direction. A first cam(29) having cam gears(30, 30 . . . ) is externally provided at the anvil so as to be integral with the anvil(8). At the rear of the first cam(29), a second cam(31) having cam gears(32, 32 . . . ) and further having cam gears(36, 36 . . . ) at its outer circumference is externally provided to the anvil(8) so as to be rotatable. At the backward position of the anvil(8), the cam gears(30, 32) contacts with each other. On the other hand, in the cylindrical portion(27) of the hammer case(5), an engaging pin(37) capable of engaging with an engaging gear(36) of the second cam(31) is provided. The engaging pin(37) can change its location by the rotative operation of a mode-change ring(40), whereby a percussion mode and a non-percussion mode is selected.

Abstract: A hydraulic rock drill comprises a housing having a piston and valve bore formed therein, a rotation motor, and a fluid connection and fluid reservoir interposed between the housing and the rotation motor. Fluid connections to the hydraulic rock drill comprise a single inlet fluid connection to the housing and a single exhaust fluid connection from the rotation motor. The working shoulder areas of the piston are proportioned so that the exhaust stroke of the piston will pressurize the fluid in the reservoir, providing a fluid inlet source for the rotation motor. When the rotation torque demand increases, pressure in the fluid reservoir and pressure in the fluid inlet connection will rise accordingly, thus providing higher rotation torque while maintaining impact power. When fluid inlet pressure reaches a predetermined limit, rotation and impact will lessen or cease altogether.

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 multi-purpose hydraulic tool of the open center and closed center type is provided with an OC/CC knob mounted on the trigger activated spool. The spool has a knob which can be turned to easily move between OC and CC operating conditions, without the use of additional tools. A check spool assembly works in conjunction with spool assembly in the open-center condition to provide for release of oil at the end of the return stroke. Adapters are provided so that crimping heads can be easily interchanged.

Abstract: A pressure-fluid driven device for generating a reciprocating movement includes a first (5) and a second relatively movable part (3), wherein a working chamber (7) is intended to be alternatively pressurised and depressurised so as to drive the parts in a movement relative to each other when the working chamber is pressurised. A valve arrangement (8) is intended to control the fluid flow into as well as from the working chamber. The inlet into the working chamber (7) is separate from the discharge from the working chamber (7). The invention also concerns a valve arrangement and a pneumatic tool.

Abstract: A pneumatic tool (20) for impacting a workpiece (22) is provided. The tool (20) comprises a casing (42) defining a chamber (48). A piston (54) is slidable within the chamber (48) along an operational axis (A). An exhaust valve (100), controlled by a pilot valve (200), slides the piston (54) by selectively introducing and releasing pressurized fluid into and out from the chamber (48). A tool bit (24) is slidable within the chamber (48) to impact the workpiece (22). Kinetic energy is transferred to the tool bit (24) from the piston (54) via an impact from the piston (54) as the piston (54) slides within the chamber (48). A shock absorbing valve (500) includes a floating collar (502) that is slidable along the casing (42) between two seal rings (504). A handle (34) is mounted to the floating collar (502).

Abstract: A rock drill includes a string of components interconnected by screw threads and connected to a shank. A percussion piston is reciprocated against the shank during a drilling operation, while a support device applies axial support to the rear of the shank, to enhance the drilling action. When the components are being unscrewed, the percussion piston is actuated to strike the rear end of the drill string, after the support device has at least partially released the axial support of the shank, to enable tensile stress to be generated in the components by the percussive impacts to facilitate unscrewing of the components.

Abstract: A diesel hammer system for driving a pile, comprising a housing, an anvil member supported by the housing, a clamp assembly adapted to connect the anvil member to the pile, and a ram member disposed within the housing. A fuel pump system injects fuel into a combustion chamber defined by the housing, anvil member, and the ram member. A coupling system detachably engages the ram member to raise the ram member from an impact position to an upper position, the coupling system comprising a trigger member that, when engaged, causes the coupling system to release the ram member. A trigger projection mounted is on the housing to engage the trigger member to cause the coupling system to release the ram member at the upper position. The diesel hammer further comprises a pre-trigger system comprising a pre-trigger member movable between an extended position and a retracted position.

Abstract: The invention relates to a controller for an unbalanced mass adjusting unit in a vibration exciter. Said controller comprises an adjusting piston for changing the relative position of unbalanced masses in the vibration exciter that is coupled to a reference piston. The position of a piston rod of the reference piston is detected by a pressure sensor and is furnished to a controller in the form of a position signal. The controller compares the position signal with an operating signal given by an operator and generates a control signal with which the position of a selector valve that controls the oil supply to or the oil discharge from the reference piston can be changed.

Abstract: The invention relates to a hydraulic ratchet wrench with a double-action hydraulic cylinder piston drive with a gear pump (20) and a piston pump (21). According to the invention, a working stroke and a return stroke are controlled through a reversal of rotational direction of a pump motor (4), whereby the necessary flow volume is produced automatically via internal flow control valves, and without additional valve controls.

Abstract: A fluid-powered impact vibrator (5), in particular a hydraulic hammer, comprising a fluid-powered percussion hammer (8) with a percussion piston (18) that is moved back and forth under the effect of a control means (10) and comprising a guide unit (7) on which the percussion hammer is supported, wherein the impact vibrator is additionally provided with a control valve, designed as a pressure monitor, for adaptation to the supplied input power. The control valve preferably is a pressure shut-off valve or a pressure-limiting valve (25) that is connected to the input pressure line (3) provided with the operating pressure, and automatically stops the percussion hammer (8) if the operating pressure resulting from the input power exceeds a specified maximum value. To stop the percussion hammer (8), either the pressure line (3) is blocked or the control means (10) is held in one of its end positions, i.e., the operating stroke or the return stroke positions.

Abstract: A pneumatic tool (20) for impacting a workpiece (22) is provided. The tool (20) comprises a casing (42) defining a chamber (48). A piston (54) is slidable within the chamber (48) along an operational axis (A). An exhaust valve (100) controlled by a pilot valve (200) slides the piston (54) by selectively introducing and releasing pressurized fluid into and out from the chamber (48). A tool bit (24) is slidable within the chamber (48) to impact the workpiece (22). Kinetic energy is transferred to the tool bit (24) from the piston (54) via an impact from the piston (54) as the piston (54) slides within the chamber (48). An energy absorbing mechanism (402) reduces the kinetic energy of the tool bit (24) after impact by the piston (54). The energy absorbing mechanism comprises a sleeve (404) that slides along the casing (42) and first (412) and second (414) pressure chambers that dissipate the kinetic energy of the tool bit (24) in multiple stages.

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 pneumatic linerbolt removing tool including a moil supported for reciprocal movement along a hammer axis within a housing, an inertial body movably mounted along the hammer axis, and a piston assembly moveable within the inertial body along the hammer axis between a striking position at which it strikes the moil and a retracted position remote therefrom. The tool further including a gas-charged accumulator for urging the piston toward the moil and air supply to a cylinder adapted to urge a biasing piston on the inertial body relative to the housing and toward the moil. The inertial body being ported so that working air is supplied to a front face of the piston assembly to urge it to a coked position away from the moil and whereby the accumulator is in its compressed state, and selectively operable porting for equalizing pressure between the front and rear faces of the piston, to continuously allow transfer of air between the faces while in operation.

Abstract: A method for controlling the operating cycle of an impact device, and an impact device. Percussion piston position is measured using a sensor (11) from which the measurement data is transmitted to a control unit (12) of the impact device, which in turn controls an electrically driven control valve (10).

Abstract: A rock drilling machine has a housing (1), a hammer piston (2) movable to-and-fro in the housing, a drilling tool (3), and a guide (4) for the drilling tool. The guide (4) consists at the surface against the drilling tool (3) of polyethyleneterephthalate.

Abstract: The invention concerns an apparatus comprising a body (2) wherein a piston (6) is mounted sliding alternately driven by an incompressible fluid under pressure, said body containing part of a tool (4) which is guided in translation in a wear sleeve (3), the end of the tool located inside the body being subjected to the repeated impacts of the piston (6), while the other end projects beyond the body and is designed to be supported on the rock or analogue to be destroyed, the tool being retained in the body by at least a transverse key (13). One of the keys (13) retaining the tool passes through aligned holes provided in the body (2), into the wear sleeve (3), and overlaps inside the inner cylindrical space of the sleeve, the tool (4) having a transverse groove (12) for the key (13) to pass through.

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

Abstract: A drive system having a housing and including a frame supported in the housing and defining an axis. The frame is rotatable about the axis and defines an interior space. A piston supported by the frame is moveable axially in the interior space and is rotatable about the axis. The piston divides the interior space and defines first and second chambers and a plurality of channels communicating between the first and second chambers. An inertial valve is coupled to the piston and is moveable between a first orientation, in which a valve stop is spaced a distance from at least one of the plurality of channels to permit lubricant flow along the at least one of the plurality of channels, and a second orientation, in which the valve stop engages the at least one of the plurality of channels.

Abstract: A method for controlling the operating cycle of an impact device, and an impact device. Percussion piston position is measured using a sensor (11) from which the measurement data is transmitted to a control unit (12) of the impact device, which in turn controls an electrically driven control valve (10).

Abstract: A pneumatic linerbolt removing tool including a moil supported for reciprocal movement along a hammer axis within a housing, an inertial body movably mounted along said hammer axis, and a piston assembly moveable within said inertial body along the hammer axis between a striking position at which it strikes the moil and a retracted position remote therefrom. The tool further including a gas-charged accumulator for urging said piston toward the moil and air supply means to a cylinder adapted to urge a biasing piston on the inertial body relative to the housing and toward said moil. The inertial body being ported so that working air is supplied to a front face of the piston assembly to urge it to a coked position away from the moil and whereby the accumulator is in its compressed state, and selectively operable porting means for equalizing pressure between the front and rear faces of the piston, to continuously allow transfer of air between said faces while in operation.

Abstract: A diesel hammer system for driving piles. In one form of the invention, a control pinion is attached to a cam member employed to adjust the volume of a fuel portion of a pump chamber. A control rack is arranged to engage the control pinion such that linear movement of the control rack is translated into rotational movement of the control pinion. A hydraulic cylinder assembly is provided having a control housing and a control piston. The control piston is attached to the control rack such that linear movement of the control piston is transferred to the control rack. Hydraulic fluid is introduced into the control housing to cause linear movement of the control piston. Conventional hydraulic controls may be used at a remote location to introduce hydraulic fluid into the appropriate portions of the control housing chamber. In another form of the invention, indicia are formed on a housing of the variable fuel pump to allow an operator to see the setting of the fuel pump.

Abstract: A piercing apparatus compact in size having a decreased number of hoses is suited for use as an iron runner port-opening machine for a blast furnace or the like furnace in an iron mill.

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: The invention concerns an apparatus comprising a body (2) wherein a piston (6) is mounted sliding alternately driven by an incompressible fluid under pressure, said body containing part of a tool (4) which is guided in translation in a wear sleeve (3), the end of the tool located inside the body being subjected to the repeated impacts of the piston (6), while the other end projects beyond the body and is designed to be supported on the rock or analogue to be destroyed, the tool being retained in the body by at least a transverse key (13). One of the keys (13) retaining the tool passes through aligned holes provided in the body (2), into the wear sleeve (3), and overlaps inside the inner cylindrical space of the sleeve, the tool (4) having a transverse groove (12) for the key (13) to pass through.

Abstract: In the hydraulic tool, a main body section includes a cylinder and a piston. A head section is attached to the cylinder, includes a movable part. The piston is capable of rotating about the cylinder with the movable part. A control section is provided to the cylinder and includes oil paths and a switching valve. A piston valve reciprocally moves to control communication between a first and a second cylinder chambers. A concave is provided in a bottom face of the cylinder, escapes an end of the piston valve from a position at which the end of the piston valve contacts a bottom face, and shuts off the communication between the chambers. A projection is provided at a position different from the concave, makes the end of the piston valve contact the bottom face and allows the communication between the chambers.

Abstract: Depending on the working and application conditions, it may be desirable to equip fluid-operated percussion devices with a mechanism that protects against no-load strokes, particularly in the interest of avoiding undesired stress. In the present case, this protection mechanism is configured such that the control unit that influences the movements of the percussion piston is blocked by a safety element in the form of a multiple-position valve, and the percussion device is halted if the percussion piston overshoots the extended position occurring in normal operation by a defined distance, thereby assuming a no-load-stroke position. The safety element (21) that acts on the control unit (5) of the percussion device (1) is automatically controlled, notably such that it is not switched to be active until some time after the startup of the percussion device (1) acted on by the working pressure. The percussion device (1) can therefore start up without being influenced by the safety element (21).

Abstract: The invention concerns an apparatus comprising a body (1) wherein is mounted a cylinder (2) inside which an impact piston (22) is guided, the fluid distribution providing the motion of the piston (22) being produced by a distributor (23) housed in a distribution box (3) mounted in the body. The cylinder (2) and the distribution box (3) are entirely contained in the enclosure defined by the body (1), the cylinder (2) is mechanically supported by one of its ends on the body (1), the distribution box (3) is mounted coaxial to the cylinder and is mechanically supported thereon and the surfaces perpendicular to the axis of the apparatus, subjected to pressure, are arranged and dimensioned such that the resultant of the hydraulic forces applied on the parts, cylinder (2), distribution box (3) are directed in the same direction towards a support located in the body of the apparatus, during all the phases of the operating cycle thereof.

Abstract: The subject invention pertains to an improved air-operated hammer which can utilize a pressurized air reservoir located near a pressurized air entrance of the hammer. This pressurized air reservoir can continue to receive pressurized air even when the hammerhead is failing and, preferably, can enable pressurized, air to enter the hammer at, a faster rate than the hammer's external compressed-air source can supply. The subject invention can utilize a compressed-air source with a lower flow rate and/or lower pressure in comparison with a typical air-operated hammer, in order to achieve the same hammer performance. Alternatively, the subject invention can utilize an equivalent compressed-air source in comparison with a typical air-operated hammer, in order to achieve superior hammer performance, for example shorter time periods to raise the hammer head leading to move hammer drops per time.

Abstract: A piercing apparatus compact in size having a decreased number of hoses is suited for use as an iron runner port-opening machine for a blast furnace or the like furnace in an iron mill.

Abstract: The invention describes a control unit for at least two tools (2, 3) operated by a pressurized medium (6), in particular hydraulic oil (7), e.g. emergency cutters (4), emergency jacks (7), etc., a delivery circuit (10, 11) for the pressurized medium (6) being provided for each tool (2, 3) and at least one pressure generator (9). At least one control device (15) comprising a control valve (23, 24) is provided in each of the delivery circuits (10, 11) for the tools (2, 3) and the control valves (23, 24) are placed in a flow connection via at least one connecting passage (25) or a connecting line as required.

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

Abstract: A hand-held, power-operated or power-assisted, crimping/er or decapping/er tool (60), for container closures, such as vial caps (C), has a hollow handle (50), housing a (pneumatic) piston-in-cylinder actuator (12, 13), with an external trigger (18) operating an internal control valve (16), to control connection of an external pressure supply, through an internal distribution block (11), and displacement of an actuator output rod (15), coupled, through a pivoted bell crank lever (10), to a demountable crimping/er or decapping/er (27).

Abstract: A soft-touch pneumatic drive unit for welding is provided. The drive unit includes a first section, a second section, and a third section. A piston rod extends substantially throughout these sections and contains a drive piston in the second section and a second drive piston in the third section. Pressurized fluid is supplied through the first section and into the second section to provide a driving force on these pistons. Cushioning fluid is supplied through the first section to the second section to cushion and slow the piston rod as an electrode carried thereby is moved toward a workpiece. A floating piston in the second section then blocks the flow of cushioning fluid from the first section with fluid pressure in the second section then decreasing to atmospheric pressure to enable full welding force to be applied through the drive pistons and the piston rod to the electrode. The cushioning fluid also aids in returning the piston components to the retracted position upon the completion of a weld.

Abstract: An apparatus for a hand-held pneumatic impact tool for use in fine hand working operations includes a handpiece, a foot-operated flow control valve with exhaust and two hand operated flow control valves. The handpiece includes a housing having a cavity and annular shoulder accommodating a stepped piston dividing the cavity into three chambers. The control apparatus provides control for a hand-held pneumatic impact tool that will return an impacting handpiece to a fine oscillation idling state quickly when the user releases the foot-operated flow control valve. The apparatus also provides ease of control for adjusting the idling ready state of the handpiece to a faint oscillation idle.

Abstract: An apparatus for a hand-held pneumatic impact tool for use in fine hand working operations includes a handpiece, a foot-operated flow control valve with exhaust and two hand operated flow control valves. The handpiece includes a housing having a cavity and annular shoulder accommodating a stepped piston dividing the cavity into three chambers. The control apparatus provides control for a hand-held pneumatic impact tool that will return an impacting handpiece to a fine oscillation idling state quickly when the user releases the foot-operated flow control valve. The apparatus also provides ease of control for adjusting the idling ready state of the handpiece to a faint oscillation idle.

Abstract: A fluidic connector comprises an independent adjunct to a pneumatic tool and is adapted to be fluidically interposed between an air supply hose and a fitting of the pneumatic tool. The connector comprises a piston-type valve member. Exhaust generated from each fastener firing operation or cycle maintains the piston-type valve member at a first position so as to permit the incoming air supply to reach the tool, however, if the tool is not fired within a predetermined period of time, the piston-type valve member is automatically moved to a second position which prevents the air supply from reaching the tool thereby disabling the same.