Abstract: A hydraulic striking device that is mounted on construction equipment such as an excavator and breaks solid rocks in the grounds using a rod that is hit by a piston is proposed. Particularly, a hydraulic striking device that can automatically switch stroke modes by sensing the intensity of pressure of an upper chamber formed at an upper portion between a piston and a cylinder in accordance with the statuses of rocks in the ground is proposed.

Abstract: The invention relates to a drive-in device comprising a drive-in piston guided in a cylinder for driving a nail component into a work piece, a combustion chamber arranged on the drive-in piston, and which can be filled with an incendive gas mixture, a charge component for producing an over-pressure of the gas mixture, and a touch component for recognising a pressing of the drive-in device on a work piece, wherein the combustion chamber is connected to an outer space via a valve component, wherein the valve component is controlled in accordance with a position of the touch component, such that, in the event of a non-ignition, the over-pressure of the gas mixture can escape via the valve component after a removal of the drive-in device.

Abstract: A reciprocating hammer with a two-stage acceleration of a pile driving ram, including a first stage in which initial gravitational acceleration is assisted by a thruster and a second stage in which the initially accelerated ram is allowed to further accelerate under the force of gravity alone for the remainder of the pile driver stroke. The force assist in the initial acceleration stage acts as a force multiplier, such that the anvil delivers impact forces to the pile greater than the impact forces achievable by gravity alone for a given stroke length/ram weight combination.

Abstract: A method of installing an electrical grounding system at a site can comprise the steps of inserting a hollow electrode into a hole formed into native soil at the site, the hollow electrode comprising an electrically conductive tube configured for communication with a fault current source, and a carbon fiber layer in conductive relationship with at least a portion of the electrically conductive tube; positioning the hollow electrode in the hole circumferentially around a ground member driven into native soil at a bottom of the hole; and electrically interconnecting the ground member and the hollow electrode.

Abstract: A hammer tool for hammering on a workpiece by a tool bit moving at least linearly in a longitudinal direction of the tool bit, configured so that a hammering element moves toward the tool bit to hits the tool bit by way of air pressure fluctuation in an air chamber when a driving element is moved from a first position to a second position. In addition, the stroke center position of the reciprocating movement of the driving element moved between the first position and the second position is configured to be changeable.

Abstract: An impactor having a housing including an upper portion and a lower portion at least a part of which extends perpendicularly from the upper portion, a ram having a first end positioned in the upper portion and positioned in axial alignment with the lower portion, an opposite end of the ram extending from the lower portion of the housing, at least one drive assembly including a first drive shaft operably coupled to a cam shaft, a cam operably coupled to the cam shaft, a cam operably coupled to the cam shaft, the drive shaft operably connectable to motor, wherein the cam is operable to rotate and positioned to contact the proximal end of the ram upon rotation of the cam, a circuit board comprising circuitry operable to receive instructions from a plurality of switches electrically coupled to the circuit board to operate the impactor, wherein the impactor is operable to deliver low amplitude pulsed strikes to a workpiece at variable frequencies.

Abstract: Provided is a process for drilling a tunnel (11) in which to place a sensor, in particular a temperature sensor, in a cooking vessel (1) comprising a bowl (2) with a bottom (3) having a thickness (e), said process comprising a step for drilling said tunnel made in the thickness (e). The drilling step comprises a pre-drilling step using a drill bit with a diameter of D1, and a deep drilling step using a drill bit with a diameter of D2, D1 being greater than D2.

Abstract: A tool body (1) has a coupler for engagement with any of a variety of tool heads such as a spade head (3), and a hatchet head (4). A tool comprising the body (1) and a tool head (3-10) is a hammer action tool. It may be used as a fork, spade, chisel, hatchet, or any tool which would benefit from a hammer action. A tubular shank (21) and a hammer (22) are together a hammer weight which is pushed down by the user until it hits a receiver (23), driving the tool head. A spring (24) returns the hammer (22) and a shank (21) back up to the start position ready for the next hammer action. It also acts to push the tool head out against a work surface for overhead work such as chiseling. A spring (25), acting between a hammer impact part (22) and the handle (21, 27) takes the shock out of the impact for the user's hands. The shank (21) and the hammer (22) slide up and down together on the box-section receiver tube (32).

Abstract: The invention relates to a ram boring device for creating horizontal boreholes, having an impact piston which moves in an oscillatory manner within a casing of the ram boring device and of which the impact frequency or impact intensity can be varied by displacing the center position of the impact piston inside the casing.

Abstract: A switching method includes starting up a percussion device in acting on a control device arranged to vary the striking stroke of the striking piston between a short striking stroke and a long striking stroke. The percussion device is forced to operate on a short striking stroke for a predetermined period of time from the starting up of the device, and in acting on the control device so as to allow the percussion device to operate on a long striking stroke, after the expiry of the predetermined period of time.

Abstract: Disclosed is a hydraulic breaker.

Abstract: A rock drilling machine equipped with an axial bearing having at least one axial piston for setting the axial position of a drill shank and for damping stress pulses returning from the rock. The axial bearing includes a module that is detachable in one piece from one installation direction. The axial bearing module includes all necessary seals, bearing surfaces, and a module frame. Supporting forces caused by the operation of the axial bearing are transmitted of support members in the module frame directly to the body of the rock drilling machine, which is a uniform piece at least at the axial bearing.

Abstract: The invention relates to an impact mechanism comprising a housing (32) with at least two stroke adjustment channels (18, 19, 20); an adjustment arrangement (31) with at least two adjustment pin channels (35, 36, 37, 135, 136, 137) arranged to interact in a manner that can be selected with the stroke adjustment channels (18, 19, 20); and a hammer piston (1) that performs reciprocating motion in the housing (32) in order to impact repetitively onto an anvil (2), which hammer piston (1) has a stroke length that can be selected with the aid of adjustment pin channels (35, 36, 37, 135, 136, 137) and the stroke adjustment channels (18, 19, 20). According to the invention, the adjustment arrangement (31) comprises an elastic element (48) arranged to maintain the adjustment arrangement (31) in place for the stroke length that has been selected; and an operating means (34) arranged to select adjustment pin channel (35, 36, 37, 135, 136, 137) and thus the stroke length of the hammer piston (1).

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

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

Abstract: A hydraulic breaker assembly including a head cap, a cylinder, and a front head, which are mounted in a casing, wherein corresponding faces of the front head and the cylinder are connected by connecting pins, wherein the cylinder and the head cap located above the cylinder are fixed together by fastening bolts, and wherein the front head, the cylinder, and the head cap are supported on an inner side of the casing by variable dampers, which are brought into close contact with the front head, the cylinder, and the head cap. The movement in the casing is thus prevented so that the head cap, the cylinder, and the front head are strongly coupled together. The length of the fastening bolt is reduced to minimize the impact-generating section so that the bolt is protected from distortion stress occurring upon striking of the rod, thereby increasing durability.

Abstract: An adjustable amplitude hammer drill mechanism comprises a main shaft having a forward drill chuck end portion and a rearward shank portion, and defining a longitudinal axis. An impact receiving member is mounted in fixed relation on the main shaft for rotation therewith. A selectively operable longitudinal-hammer member is mounted on the main shaft for free rotation of the main shaft with respect to the longitudinal-hammer member and for operative engagement with the impact receiving member. Rotation of the main shaft and impact receiving member about the longitudinal axis when the longitudinal-hammer member is in force transmitting engagement with the impact receiving member, causes the longitudinal-hammer member to move in a reciprocating motion between the forwardly displaced position and the rearwardly displaced position, and transmits impact forces forwardly along the longitudinal axis to the main shaft.

Abstract: The invention relates to a striking device (5) comprising a striking mechanism (8) which is driven by a pressure medium. Said device comprises a percussion piston (13) which can be displaced back and forth by means of a control device and a control valve which is embodied as a pressure shut-off valve (19) or as a stop valve, said control valve automatically stopping the striking mechanism if it exceeds a predetermined maximum value based on the working pressure controlling the inlet line, blocking the pressure line (3) or maintaining the control device in one of the and positions thereof. The inventive striking device also comprises a hydraulic catcher buffer which is used to brake the percussion piston when it exceeds a predetermined impact plane. According to the invention, the control valve must remain deactivated at least as long as the percussion piston is displaced on the hydraulic catcher buffer.

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

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

Abstract: A hydraulic breaker assembly including a head cap, a cylinder, and a front head, which arc mounted in a casing, wherein corresponding faces of the front head and the cylinder are connected by connecting pins, wherein the cylinder and the head cap located above the cylinder are fixed together by fastening bolts, and wherein the front head, the cylinder, and the head cap are supported on an inner side of the casing by variable dampers, which are brought into close contact with the front head, the cylinder, and the head cap. The movement in the casing is thus prevented so that the head cap, the cylinder, and the front head are strongly coupled together. The length of the fastening bolt is reduced to minimize the impact-generating section so that the bolt is protected from distortion stress occurring upon striking of the rod, thereby increasing durability.

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

Abstract: A valve device (V, 4?) for controlling the movement in a machine housing (2) of a reciprocating percussion piston (3) of a percussion device (1) for a rock drilling machine with a first chamber (5) that can be pressurized for forward driving of the percussion piston (3) and a second chamber (8) that can be pressurized for back-driving of the percussion piston (3), wherein the valve device includes a to and fro movable valve element (20), the movement of which being controlled as a response to the position of a valve portion (V) of the percussion piston in a valve housing portion by periodically pressurising a signal chamber (21) actuating the movement of the valve element over signal conduit means (22, 23, 24).

Abstract: A percussion device having, inside a machine housing (7), a movable percussive piston (2), the movement of which being controllable through a movable valve body (5), which is arranged to, in dependence of a signal indicating the axial position of the percussive piston, alternately to a pressure source and to a low pressure connect a chamber, in which a driving surface on the piston (2) is located, whereby control channel means (10, 12; 10?, 12?) for transmitting said signal have opening means opening into a cylinder space for receiving the piston (2) for co-operation with a control edge (11,13) on the piston. Adjustment means are arranged for making possible an adjustment of which axial position of the piston said signal is transmitted. The adjustment means includes at least one axially displaceable control means (9, 9?, 9?), which contacts the piston, and which includes a portion (10, 12; 10?, 12?) of the control channel means including the opening means.

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

Abstract: A percussion tool is described and which includes a housing mounting a tool bit; a reciprocally moveable hammer borne by the housing and which is operable to repeatedly strike the tool bit; and a reciprocally moveable piston enclosed within the hammer and which imparts reciprocal movement to the reciprocally moveable hammer.

Abstract: A fastener installation tool to install fasteners, such as rivets, risers, standoffs, and other types of fasteners operates upon vacuum and air pressure. Fasteners are installed with minimal reactive forces to the operator's hand, thus reducing the risk of repetitive injuries to the operator's body. Vacuum retains the fastener within the tool tip and retracts a piston, until an operator simultaneously presses the fastener against a work piece and actuates an actuation element on the tool. This causes air pressure to quickly thrust the piston against a hammer pin to drive in the fastener, transferring kinetic energy from the piston to the fastener without appreciable kick-back to the operator. A control system provides a source of vacuum and air pressure to the tool. Methods of using a fastener installation tool are also described.

Abstract: A power tool (1) has a percussive driving implement for driving an impact tool (8). The driving implement, which may be hydraulic or pneumatic, retracts the impact tool (8) on its return stroke, against the force developed by heavy-duty elastic ropes (24). During the impact stroke the impact tool (8) is urged downwardly by the elastic ropes and, if the tool is upright, by gravity. At the start of the impact stroke the ram (10) is uncoupled by a ball clutch. At the beginning of the return stroke the ball clutch acts to couple the ram once again to the weight (20) and impact tool (8), in order to lift these to the retracted position. The uncoupling of the ram for the impact stroke reduces the loss arising from the resistance of the ram.

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: 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 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: 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 percussion electrical hand-held tool including a housing (10), a percussion element (2) located in the housing, and a planetary gear unit (5) located in the housing (10) for converting a rotational movement (107) of the drive shaft (&ohgr;) of the hand-held tool (8) into a reciprocating movement (&ugr;) of the percussion element (2), with the planetary gear unit (5) including a sun gear (6) changing of a setting (&agr;) of which provides for adjusting of an impact amplitude of the reciprocating movement (&agr;) of the percussion element (2), and control unit located in the housing (10) for adjusting the impact amplitude in accordance with a manual axial force applied to the handle of the hand-held tool (8).

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 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 an annular ring in the bore of the tool and thus altering the distance required for the piston to reach impact collision with the anvil. The impact tool also includes a handle containing a receiving-recess and a handle-attachment unit to permit manual removal and installation of the handle. The handle-attachment unit includes more than one protruding member positioned a distance into the receiving-recess, more than one groove on the outside diameter of body and running a distance and in a direction substantially parallel with the central longitudinal axis of the body and then changes direction and rotates around the central longitudinal axis of the body a distance.

Abstract: The present invention provides a device for breaking up a paved surface which attaches to a host transport, such as a skid steer or backhoe, having a hydraulic power supply and preferably comprises a closed hydraulic system which includes a regenerative and concentric type double hydraulic cylinder arrangement adjustably supported within a vertical frame. The cylinder is operably attached to a weight such that when fluid is pumped into a first chamber, a piston drives a rod, thereby lifting a weight while at the same time, the piston forces hydraulic fluid from a second chamber to the host. The piston separates the first chamber from the second chamber within the cylinder. Upon reaching a prescribed height, a valve is opened, allowing fluid to flow from the first chamber into the second chamber, thereby allowing the weight to drop rapidly under the influence of gravity.

Abstract: A fluid-operated percussion device (1) having a percussive piston (3), which alternately executes a work stroke and a return stroke due to the effect of a control. To avoid no-load strikes, in one embodiment of the percussion device (1), the percussive piston (3) is shut down if it has overshot the extended position occurring in normal operation (long- and/or short-stroke operation) by a predetermined distance in the work-stroke direction (arrow 3e) and reached a no-load-strike position. For this purpose, the interior (2d) of the work cylinder (2) that receives the percussive piston (3) additionally has a no load-strike opening (20a), which is connected to the pressure line (8) of the percussion device (1) with an interposed safety element (21) that can be switched between an inoperative position and an operative position.

Abstract: A collet assembly is provided that securely holds tool bit shafts therein while allowing them to be readily and easily interchanged. The collet assembly herein has a very few number of parts and is easily assembled without the need for any special tools or machines therefor. In a preferred form, the collet assembly provides for release of the tool shaft by a forward sliding action of a collet sleeve. In this manner, rearward forces acting on the sleeve in an axial direction such as can occur during tool operations will not cause the tool shaft to be accidentally released. Another advantage is the use of a retaining member for releasably holding the shaft. The retaining member avoids the use of detent balls as in prior collets which can require ramp surfaces formed to very precise tolerances to engage and shift the balls into and out of a holding position on the shaft.

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: A percussion piston for use in a drilling apparatus includes a drill bit and at least three tubular parts which increase in diameter in a direction extending from the drill bit toward a rear end of the piston. The piston further includes flanges positioned between the tubular parts and a first corresponding delivery space at the rear end of the piston. At least two additional corresponding delivery spaces are positioned between the first corresponding delivery space and the drill bit. Channels allow the transport of pressurized hydraulic fluid to and from the first and additional corresponding delivery spaces such that an energy pulse produced by impact of the piston on the drill bit is almost completely absorbed by the drilled object.

Abstract: A pneumatic downhole impact drill has a porting system for automatically supplying pneumatic pressure fluid from a fluid delivery tube received within an axial bore in the impact piston to the opposite ends of the piston operating cylinder as the piston reciprocates. A flange on the delivery tube is slidably mounted in a cavity in a mounting hub assembly. Passageways provide fluid communication between the pressure fluid inlet plenum and the operating chamber side of the cavity and between the back chamber and the inlet plenum side of the cavity. Fluid pressure forces acting on the opposite faces of the flange and on the top end surface of the delivery tube reciprocate the delivery tube between upstroke and downstroke positions. Positioning the delivery tube in the upstroke position increases the axial distance that the piston must travel before the pressure fluid supply is connected to the back end of the operating chamber on the piston upstroke.

Abstract: In forging hammers, according to the present invention, more than one inlet valve is employed and more than one exhaust may be employed. The force of impact for a particular blow is controlled by the number of valves employed and the timing of the opening and closing of those valves relative to one another. By making successive adjustments with different combination of valves, the controls may be calibrated so that the same ram force may be repeated. Knowing the valve settings required to produce differing amounts of force, it is possible to program the settings into the memory of a computer, so that when a particular impact force is selected the appropriate valve timing will be reproduced and the desired force obtained. It is also possible to set up a sequence of blows of differing selected force, setting each blow using the computer memory.

Abstract: A pile hammer for driving down hollow piles from an upper end thereof includes a hollow pile cap adapted to rest and support the hammer on a upper end of the pile being driven. The cap has an anvil surface for receiving blows from a ram which is slidably disposed on a hollow tubular base extending downwardly from the pile cap and having a lower end portion extending into the hollow pile being driven below the level of the pile cap. The ram is slidable on an upper portion of the hollow tubular base and has an annular lower end face adapted to strike the anvil surface of the pile cap when the ram is released to drop from an elevated position above the pile cap. A ram lift system is provided in an upper portion of the hollow tubular base for lifting the ram to an elevated position a selected predetermined height above the pile for release to drop downwardly and strike a driving blow against the anvil surface on the pile cap.

Abstract: A pile driver arrangement including a reciprocal impact member connected to a piston rod which is also connected to a reciprocal piston located in a hydraulic cylinder having a lower rod end and an upper blind end. A hydraulic fluid tank and a pump for supplying hydraulic fluid from the tank to the lower rod end of the hydraulic cylinder to lift the piston and the impact member. A first hydraulic fluid conduit connecting the upper blind end of the hydraulic cylinder and the lower end of the hydraulic cylinder and a check valve to prevent the flow of hydraulic fluid from the lower end to the upper end of the hydraulic cylinder. A second hydraulic fluid conduit connecting the pump and the lower end of the hydraulic cylinder and a control valve in the second conduit for controlling the flow of hydraulic fluid from the pump to the lower end of the hydraulic cylinder.

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 pile driver arrangement including a reciprocal impact member connected to a piston rod which is also connected to a reciprocal piston located in a hydraulic cylinder having a lower rod end and an upper blind end. A hydraulic fluid tank and a pump for supplying hydraulic fluid from the tank to the lower rod end of the hydraulic cylinder to lift the piston and the impact member. A first hydraulic fluid conduit connecting the upper blind end of the hydraulic cylinder and the lower end of the hydraulic cylinder and a check valve to prevent the flow of hydraulic fluid from the lower end to the upper end of the hydraulic cylinder. A second hydraulic fluid conduit connecting the pump and the lower end of the hydraulic cylinder and a control valve in the second conduit for controlling the flow of hydraulic fluid from the pump to the lower end of the hydraulic cylinder.

Abstract: A pneumatic hammer is provided which includes a working piston (16) movable in a working cylinder (22) and defining therewith front and rear cylinder working chambers (23, 24, respectively). The working piston (16) impacts upon an anvil (15) to drive a drill bit (12) through utilizing a source of compressed air. An adjusting mechanism (37) adjusts the length of the return stroke of the working piston (16) in dependence upon the supply pressure of the compressed air.

Abstract: An air-operated hammer is provided for removing risers or gates from castings. The hammer includes a piston having a rod to which an impact member is releasably latched. Operation of the piston is controlled by a pneumatic logic control circuit, the operation of which is initiated by simultaneously depressing a pair of thumb-operated pneumatic switches. When actuated, the control circuit acts to cause the piston to retract to cause the impact member to compress one or more blow-delivery springs, with the latch being automatically released, upon desired loading being achieved, to permit the release of the stored energy in the springs resulting in the impact member being impelled against a gate or riser to be broken off. Meanwhile, the circuit operates to reverse the direction of movement of the piston so that it extends to be automatically once again latched to the impact member.

Abstract: Three tubular elements are rigidly bundled together so as to have, in use, a common upper end elevation. The first element is closed at its upper end by a rigid cap element and depnds from the common upper end by approximately 30 centimeters (approximately two feet). The second element consists of a substantially identical length of tube, open at its upper end, depending to a plug element closing its lower end, from which another identical length of tube coaxially depends to an open lower end at about 62 centimeters (marginally greater than four feet) below the upper end. The third element depends from the common upper end through a distance preferred to be between one hundred fifty two centimeters and one hundred eighty three centimeters (between approximately five and six feet), for use as a handle.

Abstract: In the hydraulic breaker according to the present invention, oil pressure at a fixed value always flows in the circuit at a low pressure side whenever the piston is raised or lowered, to prevent the need for an accumulator in the circuit at the low pressure side. At the same time, a high pressure oil is required during the raising and lowering of the piston, bringing about less of a change in the surge pressure, attributing to the fact that there is no need for an accumulator in the circuit at the high pressure side. Moreover, the hydraulic breaker of the present invention is advantageous by providing an increased striking force because the high pressure oil is used, in addition to the reaction force of the compressed nitrogen gas, when the piston is lowered to strike the chisel.