Abstract: A hammer assembly which decreases the severity of impact shocks generated by the hammer assembly during operation thereof is disclosed. The hammer assembly includes a housing defining a chamber. The housing further defines an injector port and an exhaust port each being in fluid communication with the chamber. The hammer assembly further includes a work tool positioned in the chamber, a piston positioned within the chamber, a first hydraulic pressure source which moves the piston in a work stroke toward the work tool, a second hydraulic pressure source which moves the piston in a return stroke away from the work tool, and a damping fluid source in fluid communication with the injector port. The hammer assembly still further includes a first valve which allows damping fluid to be advanced from the damping fluid source and into the chamber during the work stroke, and prevents damping fluid from being advanced from the damping fluid source and into the chamber during the return stroke.

Abstract: A pneumatic impact breaker comprises a housing (11) with a cylinder bore (20), a hammer piston (28) with a piston head (63) and an impact delivering stem portion (64), an anvil (14) displaceably supported in a cylinder bore extension (50) and normally abutting against the shank (15) of a working implement (16), an annular energy absorbing air cushion chamber (59) is formed between the hammer piston (28), the cylinder bore (20) and an annular shoulder (49) in the cylinder bore (20), wherein the piston head (63) is formed with two axially spaced end portions (65, 66) for guiding and sealing cooperation with the cylinder bore (20).

Abstract: The present invention relates to a buffer mechanism of a hydraulic impact apparatus of a rock drill, and the like, and the buffer mechanism reduces damage by buffering the reflected energy from a shank rod (2), and enables to apply impact by advancing a bit so as to contact the rock even when a rock drill main body (1) cannot advance to a predetermined position for lack of thrust before the next application of impact after the rock drill main body once retracted, thereby to improve the efficiency of impact application. In a rock drill including an impact mechanism for applying impact to the shank rod (2), and a chuck driver bush (13) for transmitting thrust to the shank rod (2) to be applied to an object to be crushed, a front damping piston (4) having thrust smaller than thrust of the rock drill main body (1), and a rear damping piston (5) having thrust larger than the thrust of the rock drill main body (1) are provided at the rear of the chuck driver bush (13).

Abstract: The striking element (1) according to the invention serves for the production of shocks which act on a tool. It has a body (3) with a plurality of parallel bores (4). A piston (2), heavy in mass, runs pressure-tight in each of these bores (4) and strikes stops which may be mounted without or within the piston (2). An end space (9) lies at each of the faces of the piston (2). The pistons (2) serve to control the function of the striking element (1). At least one of the pistons (2) produces shocks on the tool. The striking element may execute working shocks in the direction of the tool and, in a special embodiment, execute loosening shocks in the opposite direction. In a special embodiment the magnitude of the energy of loosening shocks may be adjusted or suppressed.The striking element is employed principally in surgery, but also in the general manufacture of apparatus.

Abstract: A reversible casing for a fluid-actuated, percussive, down-the-hole drill is provided with a tubular body having an internal surface forming a bore extending along a longitudinal axis. The internal surface has a profile that is a mirror image about a centerline axis perpendicular to the longitudinal axis. The profile is provided with alternating undercut portions and land portions, with a portion of the undercut portions being in an annular scalloped configuration comprising a plurality of longitudinally extending parallel grooves in the internal surface.

Abstract: The impact tool is provided with a piston (15) oscillating within a cylinder (10). For selecting, with which piston impact surface the piston (15) impacts on the head (7) of a tool holder (2) and accordingly for the selection whether the impact tool generates forward or rearward strikes, respectively, the cylinder (10) is displaced pneumatically between two positions. The displacement occurs depending on the position of a switch (21). This changing of the impact direction is simple and makes it possible to fix the tool holder in the housing (1) making the impact tool sturdy.

Abstract: A valveless percussive pneumatic drill includes a housing, a piston in the housing, reciprocating along the axis of the housing, a piston support bearing in the housing and an air distributor in the housing, the air distributor being mounted in the housing for flexible elastic movement therein, to permit slight misalignment of the piston with respect to the axis of the housing.

Abstract: A hydraulic striking device requiring no complicated adjustment of the flow rate of hydraulic fluid from the hydraulic pressure source of a hydraulic construction machine, etc. and operable by utilizing the power unit of a variety of such hydraulic machines. The adjusting valve (8) is disposed inside the main body near the control valve (5) and used to restrict the flow of hydraulic fluid ejected from the upper piston chamber (16) and passed through the control valve (5) with respect to the pressure of the hydraulic fluid supplied into the upper chamber (12) before flown from the outlet (11) to control the pressure in the upper piston chamber (16). Thus, a nearly constant, appropriate operating pressure can automatically be maintained irrespectively of the flow rate of the hydraulic fluid supplied from outside.

Abstract: A valveless percussive pneumatic drill includes a housing, a piston in the housing, reciprocating along the axis of the housing, a piston support bearing in the housing and an air distributor in the housing, the air distributor being mounted in the housing for flexible elastic movement therein, to permit slight misalignment of the piston with respect to the axis of the housing.

Abstract: An impact borer having a shell and an air drive within the shell. The air drive includes a ram for reciprocation within the shell and a manifold joined to the shell. The manifold defining an inlet passage delivering air to the air drive and an outlet passage exhausting air from the air drive, and a duplicate passage interconnecting the inlet and outlet passages within the manifold.

Abstract: This heavy duty equipment comprises a working cylinder, a striking piston, an upper lid and a holder of a drill bit. An anterior side duct in the wall of an upper working space of the working cylinder, communicating via an upper filling duct and a posterior side duct with a storage space provided in the upper lid, and an anterior bypass duct communicating via an axial duct in an axial pin and a posterior bypass duct with the storage space, axially define in the upper working space of the working cylinder, a compression space confined by the inner wall of the working cylinder, and further by an anterior face of the upper lid and by the external surface of the axial pin. The upper lid together with the axial pin and the in-built storage space form an assembly group in which a water valve is received.

Abstract: A device for removing pins, nails, dowels, rods, and the like from material which includes wood, metal, concrete, and human and animal bone, includes a pneumatically actuated piston producing a reverse impact striking effect which causes extraction of the pin from the material. The device includes a main housing comprising a tool handle, an elongated barrel partially mounted in the tool handle, and a muffler housing fitted on the barrel and abutting the tool handle. A central chamber extends the length of the barrel, and disposed within the central chamber is a shaft which is adapted for linear reciprocal movement therein. An anvil is mounted at the inner end of the shaft and a tool holder is mounted at the opposite end of the shaft. Slidably disposed on the shaft is a piston which is adapted for linear reciprocable movement thereon for forcibly striking the anvil.

Abstract: Improvements to diesel power hammers which allow the hammers to be operated smokelessly are disclosed. Kerosene and synthetic oil replace diesel fuel and mineral oil as fuel and lubricant, respectively, in hammers incorporating prior art design improvements by Makers thereof. Other combustibles such as gasoline may be added to the kerosene fuel to improve the quality of combustion and thereby further reduce the emission of smoke.

Abstract: A piston is oscillating periodically within a cylinder, propelled by compressed air. At at least one of its end positions, the piston generates a stroke that acts on a working tool, e.g. a rasp. The sizes of the piston surfaces acted upon by the compressed air and the capacities at the cylinder volumes limited by the piston are dimensioned such that the impact momentum of the piston at both end positions is essentially the same. In case of a bone rasp working tool this equal momentum of the stroke advancing the rasp into the bone and the stroke loosening the tool by retracting it, leads to an optimum working of the bone and as little stress as possible on the patient.

Abstract: A hydraulic breaker includes a piston which is designed in the five-staged configuration including a first stage, a second stage, a third stage, a fourth stage and a fifth stage. The second stage is dimensioned to have a largest diameter, the fourth stage is dimensioned to have a larger diameter and the first stage, the third stage and the fifth stage are dimensioned to a same smallest diameter, respectively. A piston reversing chamber, a low pressure hydraulic chamber in which low pressure is normally present for the piston, a low speed pilot chamber for driving the piston at a low speed, a high speed pilot chamber for driving the piston at a high speed and a high pressure hydraulic chamber in which high pressure is normally present for the piston are sequentially formed in the space between the piston and the inner wall surface of a cylinder.

Abstract: A downhole percussion drill or hammer (100) is disclosed having an outer casing (2) in which a reciprocating piston (26) which periodically impacts a drilling bit (16) disposed at a bottom end of the casing. A top chuck (1), attached to the top end of the casing, conducts pressurized air to the interior of the casing. A flow tube (5) includes a supply passage (27) and an exhaust passage (10). No cylinder sleeve exists between the inner diameter of the casing (2) and the outer diameter of the piston (26). Rather, the flow tube (5), piston (26) and interior structure of the casing cooperate to direct pressurized air alternately to the top and bottom ends of the piston while alternately opening and closing the exhaust passage. Accordingly, for a predetermined outer casing diameter, a relatively thicker casing wall and relatively larger top piston surface results in higher relative performance than prior hammers having a cylinder sleeve.

Abstract: Replacing valves in prior percussive devices, the distributor is a simple tube, which can be of plastic construction, for admitting operative compressed air to drive and return chambers at opposite ends of the centrally-bored hammer piston. The tube-distributor effects a fine, substantially sealing, relatively slidable clearance with the hammer piston bore. The housing is a simple, uniform bore diameter cylinder in which the hammer piston reciprocates; tight-concentricity tolerance machining of the confronting inside and outside diameters of the cylindrical housing, distributor and hammer piston, respectively, is unnecesssary.

Abstract: In a device for controlling a pneumatic pile-driving or ram drilling apparatus having an internal, reciprocating ram, the control is effected in a forward stroke phase, a reverse stroke phase, and a subsidiary phase for the supply of air via a control device to a ram. The subsidiary control phase is a delay phase, in which subsidiary compressed air is fed to the front of the ram via time-delay means to take effect with an interval after that flow begins whereby to be substantially effective only in extending the reverse stroke of the ram. An apparatus is provided having a housing, in which the ram is reciprocated and compressed air admission is controlled by the control device which projects into the rear face of the ram and cooperates with the control ports in the ram to control the forward and reverse stroke movements of the ram. At least one supplementary control port, provides a time-delay device with which subsidiary compressed air is additionally fed on to the front of the ram.

Abstract: An improved reversing mechanism in an impact hole drilling tool having a tubular body with a forward ground piercing end and a rearward pneumatic supply end. The reversing mechanism includes a slot coacting with a key to guide an interior tool valve in relative longitudinal movement when shifted from one of its directional motion positions to the other. The mechanism also has elements for biasing the valve mechanism longitudinally toward its forward motion position and rotationally toward at least one relative mechanism orientation wherein the key and slot are not aligned. Tool direction reversal, from forward to reverse direction, occurs without interruption of the pneumatic supply by applying rotational and pneumatic longitudinal force against the biasing elements, returning the tool to its forward direction position upon interruption of the pneumatic force.

Abstract: A compression-vacuum action percussive machine is proposed, which has a casing (1) accommodating a tool (7) and a cylinder (2) with a drive piston (3) and a striker (4) having a chamfer (10) on the end face engageable with the tool (7), and also a means for trapping the striker (4), which means is made in the form of a sleeve (11) with an annular groove (13), wherein a resilient ring (14) is mounted. The sleeve (11) has an inner annular rib (15), the diameter of which is smaller than the diameter of the inner wall (12) of the sleeve (11), the annular rib (15) being positioned at the end face of the sleeve (11) facing the striker (4). The inner diameter (d) of the resilient ring (14) is smaller than the diameter (D) of the extension (9) of the striker (4), which extension is situated after the striker chamfer (10).

Abstract: A percussion drill comprises a drill bit and a reciprocable hammer piston for imparting blows to the bit. Pressurized air is supplied to the piston for reciprocating the piston. Some of the air is by-passed to an exhaust passage and is exhausted ahead of the bit for removing cuttings. An indexable choke valve is disposed in the exhaust passage for regulating the amount of air which is exhausted. The choke valve comprises a portion of a valve carrier which carries a check valve at its rear end. The valve carrier is rotatable to produce an indexing of the choke valve. The valve carrier is insertable in a front-to-rear direction into a central opening of a rear sub and is secured to the rear sub by a pin which also holds the choke valve in selected positions of adjustment.

Abstract: A percussion drilling apparatus has a control unit in which a displacement reversing unit is arranged axially adjacent to a piston control unit, with the result that the control edges for the apparatus advance and apparatus return can be arranged in separate control sleeves. This control unit makes it possible to achieve better apparatus characteristics and higher overall efficiency of the apparatus.

Abstract: A pneumatic impact tool comprising a casing having an interior space in which is mounted a piston for reciprocations under the action of compressed air for delivering useful blows, and ports of at least two exhaust passages opening into the interior space, one of the exhaust passages permanently communicating with atmosphere and the other with a chamber for preliminarily reducing the exhaust pressure. The chamber for preliminarily reducing the exhaust pressure is permanently connected through at least one passage to the exhaust passage communicating with atmosphere.

Abstract: A percussive air tool with a hollow cylindrical stepped housing having air inlet and air exhaust ports. A stepped hammer reciprocates inside the housing and has an axial central bore with a tube element disposed in the bore. The tool includes, work stroke and return stroke chambers, an air supply hose pipe with an air feeding valve, and a rod-clamping device arranged in the forward portion of the housing. The smaller step of the hammer has a neck portion or groove adapted to communicate the air inlet port with the interior of the larger step of the housing, an open annular cavity being formed between the tube element and the walls of the hammer bore.

Abstract: In deep bore drilling it is usual to use a fluid operated percussive hammer to provide necessary drive for the boring operation. However a difficulty which is encountered with hammers which are currently in use is that the manufacture of the components for such hammers involves considerable amount of precise machining which not only increases the manufacturing cost of such units but also reduces the service life of the components. Some of the typical hammers in use generally comprise an outer cylindrical casing with a feed tube positioned concentrically within the casing and a piston slidably mounted within the casing and over the feed tube to reciprocate therein and impact on a drill bit mounted in and retained at the bottom of the casing.

Abstract: A hollow rotary drilling tool is equipped with a percussion device which comprises a nozzle comprising a cylindrical annular duct followed by a divergent annular duct. The divergent duct opens into flow paths, a central path and a peripheral path, through which drilling mud flows alternately in order to cause reciprocation of a percussion head located in the central path. The peripheral path joins the central path downstream of the percussion head. The external conical surface of the divergent duct is connected to the external cylindrical surface of the cylindrical duct via a radial step, which makes the flow in the peripheral path unstable, so that under normal conditions of flow the drilling mud flows along the central path. Flow along the central path is interrupted by contact of the percussion head with an abutment, which limits its movement in one direction, and which closes the central path, causing flow to switch to the peripheral path.

Abstract: This invention pertains to a hydraulic reciprocating device having a housing and a piston in the housing. The piston has a first and second surface, and a means for intermittently communicating the first surface of the piston with a hydraulic pressure source. Also provided is a means for continuously communicating the second surface of the piston with pressurized fluid such as pneumatic fluid. The piston moves in a first direction when the hydraulic pressure source communicates with the first surface of the piston and the piston moves in a second direction when the hydraulic pressure source does not communicate with the first surface of the piston.

Abstract: A vibrationless percussion tool is disclosed characterized by use of a piston mounted for reciprocal movement against a constant pressure force within a casing to cyclically impact an anvil disposed adjacent the distal end of the casing. A spool valve is disposed within the interior of the piston and is adapted to travel in unison with the reciprocating piston except during mechanical actuation initiated adjacent the extreme downstroke and upstroke position of the piston within the casing. The constant pressure force is continuously applied to one side of the piston and by mechanical actuation of the spool valve, the volume disposed on the opposite side of the piston is alternatively vented and pressurized to cause reciprocation of the piston against the constant pressure source.

Abstract: A compressed-air pile-driver, especially for axially insertable tools, including a ram arranged in a housing. The interior of the housing is divided by the ram respectively into an upper compression or expansion chamber and a lower compression or expansion chamber, which can each be alternately connected to a compressed-air source via air connection pipes and a control valve, with each having an air-outlet orifice opened alternately by the ram. In the upper expansion chamber, a pressure chamber, into which the upper air connection pipe of the upper expansion chamber opens, is divided off by an intermediate plate which is approximately parallel to the end face of the ram. Located in the intermediate plate is at least one orifice which connects the pressure chamber to the upper expansion chamber, and which is closed in a leak-proof manner by the ram in its upper dead-center position, the ram additionally being retained firmly in its upper dead-center position by a retaining device.

Abstract: An automatic, fluid actuated, external control system for a pile hammer or the like is provided that can vary the operating stroke length of a pile hammer and that can be used to operate the pile hammer in either a continuous or single stroke mode. A series of axially spaced orifices in the hammer housing exhaust pressurized fluid from the housing in a sequence controlled by the position of the hammer piston within the housing. The orifices are coupled by conduit to a series of pressure sensitive valves external of the pile hammer. The pressure sensitive valves control the delivery and exhaust of pressurized motive fluid to and from the pile hammer in response to the position of the hammer piston within the hammer housing.

Abstract: A valveless pneumatic hammer comprises a hollow casing having a backhead assembly at one end and a bit assembly at the other, and a piston reciprocable in the casing. There is a chamber divider at the backhead end of the casing which co-operates with the piston for conducting fluid under pressure into alternate chambers, one at each piston end, for reciprocation of the piston. A chamber divider is located within the casing by a locating split ring which holds the chamber divider axially against the backhead assembly. The chamber divider also has a recess in the end thereof nearest the piston which together with a bore in this piston end, comprises the fluid chamber at this end of the casing.

Abstract: There is disclosed an impact applying mechanism, particularly as applied in a subterranean drilling apparatus, and comprising a cylinder (13) arranged with its axis substantially vertical and connected to the member to which impact is to be applied, a piston (5) slidably mounted within the cylinder (13), means to admit pressure fluid to the cylinder (13) below the piston (5), at least one valve tube (24), slidably mounted in the base of the cylinder (13), coil springs (30) to bias the upper end of the valve tubes (24) into sealing engagement with the underside of the piston (5) when the piston is in its lowest position, a flange (26) on the upper end of the valve tubes (24) upon which fluid pressure in the cylinder (13) acts to produce a force urging the end of the valve tubes (24) into contact with the underside of the piston (5), and further coil springs (32) to provide a force to said valve tubes (24) of a magnitude which increases as the piston (5) moves upwardly relative to the cylinder (13) to subsequen

Abstract: A massive piston, which might be called a "ram", except that it does not strike anything during operation, reciprocates with bouncing action up and down within a cylinder. An annular pressurized gas storage chamber encircles the piston and travels up and down with it. Pressurized gas is continuously supplied into this movable chamber to be temporarily stored therein. As the piston descends toward the lower end of the cylinder, pressurized gas from this travelling chamber is automatically suddenly allowed to bypass the lower portion of the piston, thereby injecting the pressurized gas into a bounce chamber between the descending piston and a bottom assembly. When this pressurized gas rushes through the bypass, it forces an exhaust valve closed.

Abstract: A hydraulic vibrator for moving a ramming or drawing body or the like has a hydraulic working cylinder, a double-acting working piston axially movable in the hydraulic working cylinder, and a device for supplying a working medium into the hydraulic working cylinder, alternately at both axial sides of the working piston so that the working piston vibrates with selectively variable frequency and displaces the ramming and drawing body or the like.

Abstract: The invention relates to a tool which incorporates a device insuring the efficient control of a percussive hammer, regardless of the drilling depth. For this purpose, drive sludge arriving in an annular space reaches an inlet of a fluid switching element of single or double stability in which the flow of fluid alternates between two fluid circuits, causing the hammer to strike and return.

Abstract: A self-propelled pneumatically operated percussion boring apparatus for boring holes in the ground of the kind which includes a percussion piston which is reciprocated pneumatically in a tubular housing is provided with a control device for causing the apparatus to make either a forward movement or a return movement. The control device comprises a control sleeve which has air ports through its wall and over which a skirt of the piston passes as, in operation, the piston reciprocates. The skirt has ports which come into register with ports in the sleeve and the sleeve is fixed in position in the housing and has a control tube rotatably mounted within it. The control tube has one or more ports through its wall and compressd air for operating the apparatus is supplied through the control tube.

Abstract: A pneumatic impact mechanism for driving rod-like members having a hollow cylindrical casing with a tail portion and a front end portion. The casing accommodates a reciprocating stepped hammer piston defining in the casing, on the tail portion side, a variable volume rear end work chamber in permanent communication with a source of compressed air. The stepped hammer piston defines, on the side of the front end portion, a variable volume front end work chamber.The stepped hammer piston has a through-passing axial bore, and its small-diameter portion cooperates with the tail portion of the casing and has radial passages. There is provided a tubular guide member or element for receiving the rod-like member arranged coaxially with the stepped hammer piston and casing and secured to the tail portion and to the front end portion of the casing in such a manner as to cooperate with the stepped hammer piston and define therewith, with the outer periphery thereof an axial passage.

Abstract: An underwater hammer, of the gas discharge type, is provided with a surrounding casing arranged in the nature of a diving bell from which liquid can be purged so that the hammer ram may move up and down with minimum resistance. A reflood tube extends down through the upper end of the casing and opens into an axial reflood passageway in the ram and liquid is pumped through this tube to obtain reflooding after each cycle of operation.

Abstract: An internal combustion type pile driver which has a cylinder, a ram adapted to slide within this cylinder, an anvil fitted into the bottom end of the cylinder and an air intake/exhaust port fixedly provided on said cylinder, is improved so that the height of rise of the ram may be adjustable. The improvement exists in providing a choke opening communicating the interior of the cylinder with the atmosphere for the purpose of adjusting a combustion gas pressure in a cylinder wall between the air intake/exhaust port and a combustion chamber, and either a choke plug or a blind plug is adapted to be fitted in to this choke opening.

Abstract: An underwater hammer, of the gas discharge type, is provided with a circumferential control valve on the hammer ram to allow free flow of water and gas upwardly along the ram in the annular clearance between the ram and a tubular sleeve in which it is guided, but to interrupt the flow of water downwardly along the ram. The control valve allows the region under the ram to be purged of water when the ram is driven upwardly in the sleeve and it prevents water thereafter from flowing back down under the ram where it would otherwise cushion ram impact on an anvil.

Abstract: A pile-driving hammer comprises a hammer cylinder, a piston accomodated in said hammer cylinder in sealing relationship with a sliding face of the hammer cylinder and means for supplying lubricant to said sliding face which consists of a lining of wear-resistant material.The pile driving hammer has a long lifetime, since cavities are provided in the lining distributed along the surface of the sliding face. In this hammer the lubricant is retained in the cavities.

Abstract: An air hammer having a main body including an elongated cavity with a ram slidably mounted therein. The ram is driven by compressed air delivered through inlet means to the cavity in such a way as to drive the ram up and down to impact a tool. Exhaust from the hammer is directed into a plurality of elongated expansion chambers which are positioned within the body of the hammer. The expansion chambers extend to each end of the hammer body and exhaust to the atmosphere through open ports. Inserts are placed within the elongated expansion chambers to divide the chambers into properly sized cavities for greatest sound attenuation. Holes extend through these inserts for the eventual passage of exhausting air therethrough. The inserts are of neoprene having a durometer hardness of from 75 to 90. The size of the expansion chambers and the configuration and positioning of the inserts are intended to provide a muffling of the noise and shock of the exhaust.

Abstract: An expandable ignition chamber within an upstanding cylinder is formed between its base and a massive free piston. Initial detonation of a combustible gas mixture within the chamber drives the piston upwardly to expose in sequence a series of vertically spaced gas inlets in the cylinder wall, through which the supply of gas is replenished to support a corresponding sequence of additional rapidly timed detonations. Repetitive seismic pulses are thereby supplied by the downward thrust of the base which is itself slidable with respect to the cylinder walls.

Abstract: A very powerful pile driver is disclosed capable of operation in the air, partially submerged or totally submerged in the ocean for driving long piles into the ocean floor in deep water construction jobs. The pile driver includes a cylindrical housing, a movable massive weight within the housing, an annular cylindrical thrust-transferring member defining a discharge chamber below this weight, and a movable driving head attached to this annular member, forming a thrust-transmitting assembly adapted to be engaged with the pile. Pressurized gas such as compressed air is discharged from gas discharge apparatus, called an airgun located within the discharge chamber and provides two driving thrusts for each discharge.

Abstract: An airhammer and core bit apparatus including a housing and a hammer piston reciprocable in the housing for delivering repeated impact blows to an anvil secured to or forming part of a core bit which produces a core in a bore hole being drilled. A central core receiving tube extends through the housing and hammer piston, through which the core formed by the bit is conducted upwardly and through the hammer piston to the top of the bore hole, part of the compressed air supplied to the airhammer being diverted to the central tube for elevating the core therewithin toward the top of the bore hole.