Abstract: A powder actuated fastener setting tool including a receiver for receiving a portion of a barrel reciprocatable therein between extended and retracted positions, and a substantially enclosed exhaust baffle disposed between the receiver and a muzzle of the barrel when the barrel is in the retracted position for baffling exhaust discharged from the tool during operation thereof. The tool also includes a spring member disposed between a cap fixedly coupled axially to a muzzle of the barrel and the receiver for biasing the barrel in the extended position, and a mechanism for removing exhaust residue from the powder actuated tool during operation thereof.

Abstract: An exhaust gas muffler for an internal combustion engine of a portable, hand-guided working tool has a housing having an exhaust gas inlet, and exhaust gas outlet, and an outlet space, wherein the exhaust gas outlet opens into the outlet space. An outlet opening is provided downstream of the outlet space and has wall elements directing the exhaust gas flow in the exit flow direction. A rebound wall is positioned transverse to the exhaust gas outlet and delimits the outlet space while providing a connecting slot into the outlet opening. The connecting slot is spaced at a distance from the outer wall of the housing that extends substantially parallel to the rebound wall. A first ramp is positioned perpendicularly to the connecting slot and slants upwardly from the rebound wall to the outlet opening. A second ramp extends in a direction of longitudinal extension of the connecting slot from an end of the insertion slot opposite the first ramp to the edge of the first ramp opposite the connecting slot.

Abstract: An air ratchet hand tool has an elongated, generally cylindrical handle portion with an axial air inlet passage therethrough, and having an outer surface with two longitudinally extending channels formed therein, each communicating with the air motor. A thermoplastic grip jacket covers the handle portion and cooperates with the channels to form therebetween two exhaust air passages which exit at the distal end of the handle. Longitudinal ribs on the jacket project radially inwardly into engagement with longitudinal recesses in the handle portion to inhibit relative rotational movement, while a lug on the handle portion extends through an opening in the jacket to inhibit relative axial movement. A flexible and resilient trigger cover covers the valve trigger and the jacket opening through which it projects.

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: An improved grip structure for a pneumatic tool, in which the grip is furnished with a valve seat mounted with a control valve; the central part of the valve seat has an intake passage, of which the outer end is connected with an intake connector, the valve seat and a ring-shaped groove of the bearing-block hole in the dynamic housing are connected and communicated each other by means of an intake passage.

Abstract: A compressed air exhaust arrangement in a pneumatic fastener driving tool. An exhaust port is formed in an upper portion of a main body, and a cover member is fixed onto the upper portion. An annular muffler member is disposed between the cover member and an upper surface of the main body to surround the exhaust port. The cover member has a lower surface formed with a plurality of cranked grooves for providing a plurality of air vent passages relative to an upper surface of the muffler member. The air vent passage allows the compressed air from the exhaust port to pass therethrough toward an atmosphere. Before freeze of the muffler member, most of the compressed air discharged through the exhaust port directly passes through the muffler member. After freeze of the muffler member, the compressed air passes through the air vent passage.

Abstract: A muffler (30) for quieting exhaust expelled from a pneumatic hand tool (10) having a handle (12), an air intake port, and an exhaust port. The muffler (30) includes an inner tube with a plurality of holes, a number of washers (36) positioned longitudinally about the inner tube (32) at the location of the plurality of holes, and an end cap for sealing off the inner tube. The inner tube is preferably formed as a spring. During use, exhaust air pass from the hand tool (10) into the inner tube, into the washers, through the washers, and out the muffler end cap. Alternative embodiments includes an outer tube.

Abstract: A pneumatic tool is disclosed which includes vibration mounts to reduce the amount of vibration transferred to the user. The vibration mounts include a pair of support members and at least one resilient vibration isolator connecting the support member in a spaced relationship. A compressed air conduit passes through the support member openings but is only directly fastened to one of the support members.

Abstract: A hydraulic breaking hammer having a machine housing including a cylinder bore and an impact piston which is reciprocatingly movable in the cylinder bore in response to an alternating hydraulic pressure, and a tool part having: (i) a head portion fitted to a front portion of the machine housing, and (ii) a guide bore which lies in line with the cylinder bore and in which a breaking tool is slidably carried and repeatedly subjected to impact by the impact piston. A seal is arranged at the front portion of the machine housing between the cylinder bore and the impact piston for separating drive hydraulics of the breaking hammer from the tool part, and a transverse slot is formed in the front portion of the machine housing between mutually opposing side wall portions of the machine housing so as to intersect the cylinder bore forwardly of the seal.

Abstract: The powder actuated tool has a modular construction which comprises: a firing pin module; a pistol grip module; and a fastener driving module. The firing pin module and the fastener driving module are readily detachable from the pistol grip module so that if any module is damaged, or needs maintenance, it may be readily removed and replaced at low cost and at no inconvenience to the user. The fastener driving module includes a barrel which is reciprocally slidably mounted in the pistol grip module. A fastener driving piston is carded in the barrel and a piston return pawl is mounted on the pistol grip module for returning the piston from a fired position to a firing position via a slot in the barrel. Combustion gas ports in the barrel bleed gases from the barrel bore adjacent to the firing chamber. The bled gases pass through external grooves in the barrel to reentry ports communicating with the barrel bore, whereby tool noise is muffled.

Abstract: This disclosure relates to an underwater excavation apparatus comprising a tube in which a propeller is mounted for rotation. The tips of the propeller blades are formed with jets supplied from a high-pressure water supply through passages in the propeller blades. The jets impinge on vanes mounted on the tube wall around the propeller to cause the propeller to rotate and thereby draw water through the tube from a inlet at one end to an outlet at the other end to act on the seabed. The apparatus is particularly useful for excavating trenches on the seabed and exposing previously covered installations on the seabed.

Abstract: A pneumatic tool is disclosed which includes vibration mounts to reduce the vibration transferred to the user. The vibration mounts include a plurality of support members and at least one resilient vibration isolator connecting the support member in a spaced relationship. A compressed air conduit passes through the support member openings and includes at least one seal disposed between said support members and the air conduit.

Abstract: A railroad spike driving tool (30) is adapted to be inserted by its shank (22') for cooperation into hand-held hammer machines of the type comprising a machine housing (10) with a cylinder (11), in which a reciprocating drive piston (14) via a gas cushion in a working chamber (12) repeatedly drives a hammer piston (15) to impact on the shank (22') during spike driving. Forward sudden displacement of the shank (22') causes the hammer piston (15) to perform a forward blow in the void and come to rest. If the tool (30), as a result of the last impact and simultaneous sideward shifting of the machine, happens to hit against the rail, a safety spring (36), pre-stressed between a rearwardly facing shoulder (34) on the tool (30) and the machine housing (10), prevents the tool (30) from bouncing back into the machine and thus from being hit by said hammer blow in the void or from releasing a new blow. Possible injury to the operator is thereby avoided.

Abstract: The invention relates to a hydraulic impact hammer, comprising a protective casing made of two side plates, and provided with attenuation elements for eliminating the noise and vibration caused by the impact hammer. According to the invention, the attenuation elements (5, 6) are arranged in the side plates (1, 2) of the protective casing, so that the attenuation elements (5, 6) can be compressed in at least three directions (X, Y, Z) of the housing (4) while fastening the side plates (1, 2) to each other.

Abstract: A pneumatic power tool includes a housing (10), a motor (14), an air inlet passage (23) in the housing (10) communicating with the motor (14), a pistol type handle (12) extending from the housing (10) perpendicularly to the application direction of the tool, and an air communication arrangement (16, 20, 23) for connecting the air inlet passage (23) to a pressure air supply conduit connected to the tool, wherein the air communication arrangement (16, 20, 23) is separated from the handle (12) and comprises an air supply passage forming member (16) connected to the rear part of the housing (10), and an exhaust air passage (25, 26) having an outlet portion (26) coaxially disposed relative to the air supply passage forming member (16).

Abstract: A flexible metal dust boot, comprising a bellows, and a surrounding protective shroud capable of withstanding high temperatures. The boot and shroud are mounted on a support plate, which can be conveniently attached to the body of a reciprocatable hydraulic or pneumatic hammer. The boot and shroud extend from the bottom of the hammer body, in surrounding relationship to the tool. The support plate forms a seal against the bottom surface of the hammer body. The bellows is attached to the plate at one end, and to the tool, in fluid tight relationship, at the other end. An air fitting in the bellows structure facilitates connection to a pressurized air source to inhibit the entry of particulate matter as well as fluids in the hammer is submerged in use. During hammer operation, the bellows reciprocates with the tool. The shroud surrounds the bellows and extends the axial length of the bellows to shield the bellows from particulate matter generated during operation of the hammer.

Abstract: Apparatus for driving anchors in the ground by gas pressure which includes on a frame to be maintained stationary relative to the ground, a mechanism for firing and combustion of a pyrotechnical composition, and for launching an anchor. The apparatus including an acoustic shield for gas expansion which is slidingly mounted on a recoil ramp so as to balance the impulse transmitted to the anchor by the force of gravity.

Abstract: A pile driver is disclosed, in which an adapter for transmitting the hammering force of a hammer provided in a hydraulically driven vibrator to a member to be driven into the ground is provided between the hammer and driven member. The adapter is formed with an oil accommodation section, in which a head portion to be hammered by the hammer is formed. The oil accommodation section is filled with oil such that the head portion is immersed in oil. A cooling unit is provided such that it surrounds the adapter. A cooling medium is circulated through the cooling unit by a circulating unit.

Abstract: A sound depressing exhaust means for a pneumatic power tool with a substantially cylindrical housing (10) and a vane motor (11) with exhaust port means (23), has an annular casing (41) surrounding a portion of the housing (10), and four expansion chambers (31-32, 34, 36, 39) arranged in series and combined with four flow restrictions (33, 37, 30, 35) and a sound trap (38). All of the expansion chambers are annular and located concentrically relative to the tool housing (10), and one of the flow restrictions has an annular screen (37) separating two of these chambers (34, 36). The last two of the expansion chambers (36, 39) in the exhaust flow direction contain high frequency absorbing elements (43, 44) of foamed plastic.

Abstract: In a preferred embodiment, a lug-removing pneumatic impact-gun air blast-deflector divertable of forwardly directed exhaust air blast, of which detachably-mountable air-blast deflector structure is mountable on the gun in a position divertable of forward air blast laterally in each of opposite lateral directions, having a vertically extending apertured portion mounted by a forwardly-located horizontally positioned bolt and inclusive of a horizontal rearwardly-extending portion having a distal end portion distally angled rearwardly-upwardly, thereby forming a laterally and upwardly directed air path positioned in front of air-blast exits of the gun.

Abstract: An explosive actuated extendable driving tool has a housing with a barrel at its front end for receiving a fastening element that is to be secured in a ceiling, wall or the like. A manually actuated reciprocatable positioner shaft is slidably received in a retainer that is mounted to the back end of the housing, the positioner shaft being biased towards the back end of the housing. A load chamber formed which is in an inner end of the barrel is configured to receive an explosive charge. A muzzle with a self-aligning spall guard and splash guard are mounted to the barrel, the splash guard being disposed about the spall guard. A noise suppression element is contained in a chamber formed between the spall guard and the splash guard. Discharge ports formed in the barrel and spall guard define exits for the discharge of combustion gases and carbon into the noise suppression element.

Abstract: A single-stroke pneumatic apparatus incorporates a hollow cylindrical frame 1) with inlet and outlet ports (2,3). A handgrip (4) containing a directional flow control (5) is attached to the upper end of the frame. A striker (6) is provided in the bore of the frame (1) with provision for reciprocating back and forth so as to divide this bore into a forward-stroke chamber (8) a back-stroke chamber (7). A tool (9) is supported in the lower end of the frame (1). A shell (10) with holes (11) surrounds the frame (1) from the outside, forming a muffling chamber (12) therewith, within a full length of the stroke of the striker (6). Additional outlet ports (15) are provided in the lower end of the frame (1) which communicate the back-stroke chamber (8) with the muffling chamber (12) located wherein is a filter (6) overlapping the holes (11) in the shell (10).

Abstract: A pneumatic ram boring machine (12) has an air-permeable hollow cylinder (2) with a sound absorbing and/or oil separating packing (9, 11) arranged in the exhaust air stream of the machine.

Abstract: A pneumatic power wrench comprising a housing (10), a rotation motor drivingly connected to an output spindle (11), a pressure air supply passage (22, 24) in the housing (10) connecting the motor to a pressure air source and a manually operable throttle valve (17) disposed in the air supply passage (22, 24) to control the pressure air supply to the motor. An adjustable pressure regulator is arranged in the air supply passage (22, 24) upstream of the throttle valve (17) to provide a desired constant air supply pressure to the motor. The pressure regulator comprises a spring biassed relief valve (32-34) which via a venting passage (42) communicates with the exhaust passage (16) of the tool upstream of a flow restricting silencer (18) mounted therein.

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 pneumatic hammer includes a cylinder tube, a piston received in the cylinder tube for reciprocation therein; a device for alternatingly introducing pressurized air into first and second cylinder chambers on either side of the piston for driving the piston back and forth and an exhaust arrangement for removing spent air from the cylinder into the ambient atmosphere. There is provided a coupling cylinder mounted within the hammer housing and generally coaxially surrounding the cylinder tube along a substantial length thereof. The support cylinder has a plurality of circumferentially distributed longitudinal ribs extending parallel to the cylinder tube. The longitudinal ribs are in contact with an inner surface of the housing and an outer surface of the cylinder tube.

Abstract: The internal absorbent layer (9) of the casing delimits an internal volume (10) around the drill (1), which volume is divided on either side of the exhaust orifice (3) by two transverse partitions (13A, 13B) into three successive expansion chambers (11A, 11B, 11C) between the exhaust orifice (3) and the outlet opening (12) to the air outside the casing.

Abstract: A vibration insulating handle for a pneumatic power tool comprising an inner tube (15) and an outer tube (16) both rigidly but adjustably attached to the tool housing (10). The inner tube (15) forms an air exhaust passage (13) which communicates with a silencer (12) carried on the extreme end of the outer tube (16). The tubes (15, 16) are radially spaced relative to each other leaving an annular heat insulating gap therebetween. A weakened portion (30) on the outer tube (16) is located adjacent the tool housing end of the latter and comprises two axially spaced pairs of peripherally extending slots (27, 28). The weakened portion (30) enables the outer tube (16) to yield elastically in radial directions to bending and shearing vibration forces transmitted to the handle during operation of the tool.

Abstract: The present invention relates to a sound-dampened driving apparatus for fasteners wherein a main valve means is arranged above a working cylinder of the apparatus and movable within a cylindrical bore. When the main valve means is in its lower at rest position, the main valve means separates the working cylinder from a source of compressed air and connects the cylinder to the atmosphere. When the main valve means is in its upper actuating position, the working cylinder is connected to the source of compressed air and the valve means blocks the cylinder connection to the atmosphere. The space above the main valve member within the cylindrical bore is capable of being alternately connected to either the atmosphere or compressed air, and includes a sound dampening means arranged in the space above the main valve member.

Abstract: A silencer for a pneumatically operated hydraulic jack equipped with an air motor is provided. The silencer comprises a first low-pressure chamber formed contiguously to the rear wall of the main cylinder of the air motor, a second low-pressure chamber formed contiguously to and behind the first low-pressure chamber, a baffleplate partitioning the first and second low-pressure chambers and having two groups of first holes formed at an angular displacement of 90 degrees from a pair of discharge holes formed diametrically opposite to each other and radially so as to discharge high-pressure air from the main cylinder of the air motor into the first low-pressure-chamber, and two groups of second holes formed at an angular displacement of 90 degrees from the two groups of the first holes respectively in the rear wall of the second low-pressure chamber to discharge air into the atmosphere.

Abstract: A plastic silencer (12) surrounds a compressed air tool (11) and forms an exhaust chamber (27) around the tool. Two exhaust tubes (31, 32) from the chamber (27) are to the greater part situated in the chamber. A number of holes (35, 36) have been drilled near the inlet ends of the tubes. As a result the building up of ice in the inlet is prevented.

Abstract: The invention concerns an anti-freezing device for pneumatic tools to avoid the immobilization of the striker piston because of freezing up. A thermally insulating sleeve, broken only at the level of the air exhaust apertures of the cylinder, separates the body of the hammer from an annular chamber into which the apertures open. An exhaust passage connects the annular chamber with the exterior and extends along the external wall of the exhaust silencer parallel to the striker piston. The exhaust silencer also is provided, above and below the annular chamber with two hermetically sealed chambers, which prevent the cooling of the naturally hot zones of the hammer by the air in the exhaust passage.

Abstract: Reciprocating pneumatic motor for rock drills and the like wherein a freely-movable hammer piston repeatedly strikes the end of a drill rod, usually a rotating drill rod. Fluid under pressure enters a single, central inlet port in the wall of a cylinder which houses the piston with alternate cycling ports being incorporated into the piston itself. Also disclosed is a novel muffler for such a pneumatic motor.

Abstract: A pneumatic power tool having a torque sensing control system is disclosed which is capable of consistently applying a precise torque to a fastener so that uniform tightening of any number of fasteners can be obtained. A torsional strain responsive transducer is mounted internally in the tool body and includes a strain gauge network mounted on a torsionally resilient portion of one of the gear cases of the drive train of the tool, the gear case being subject to a reaction component of the torque being transmitted through the drive train. The strain gauge network provides a control signal which effects energization of a solenoid-actuated air shut-off valve in the handle of the tool to automatically terminate the operation of the tool when a predetermined torque is obtained at the output spindle. The control system permits adjustment of the torque output of the tool and provides a visual readout of such output.

Abstract: A rock drill includes a drill shank with a boring head at one end and laterally enclosed for at least a portion of its length by a tubular shell. A helix extends around the outside of the tubular shell for carrying borings away from the boring head. Supporting members formed of a sound attenuating material are located between the helix and the other parts of the rock drill.

Abstract: Rock drilling apparatus including a pressure fluid driven rock drilling machine (10) and a drill unit (11). The drill unit (11) includes a drill rod (18), a drill bit (16) and a tube (20) surrounding the drill rod (18). The drill rod (18) has a collar (22) in front of a shank (21), the collar (22) maintaining the tube (20) rotatably therebetween and between the drill bit (16). The rock drilling machine (10) includes coupling device (46; 57), a socket means (42) and a rotation chuck (44) for receiving and holding the tube (20) and shank (21) connected to the machine (10), the tube (20) being radially spaced around the drill rod (18) and non-rotatably connected to the socket means (42).

Abstract: A device for absorbing kinetic energy derived from an element oscillating in a direction parallel to a longitudinal axis of the device. The device has a housing coupled to the oscillating member and defining a chamber bounded by opposite inner end walls and an inner lateral wall of the housing. The inner end walls are generally transverse to and the inner lateral wall is generally parallel with the axis of the device. An oscillation quencher body which is situated in the chamber, has opposite end faces oriented towards respective inner end walls and a lateral face oriented towards the inner lateral wall. A resiliently deformable impact member is situated between each end face of the body and a respective inner end wall of the housing. Further, at least one groove is provided in the lateral face of the body. The groove has a length generally transverse to and a width generally parallel with the device axis.

Abstract: A ram block for driving piles and the like into the ground has a lead mass (15) which is enclosed in an inner cylinder (10) and in the space between this and an outer cylinder (11). The cylinders are interconnected at the lower end of the ram block where a cap (14) is arranged in the inner cylinder.

Abstract: A reciprocating piston jack-hammer is provided with an easily detachable air distribution mechanism, a resilient casing for muffling the noise by the emitted air, and a shock absorbing housing. A cylindrical tube houses the reciprocating piston and has molded thereabout a housing with air channels between the housing and the tube. The handle of the jack-hammer has a cavity and a mechanism which controls the supply of compressed air to the distribution system. The distribution system employs two parts, one disposed in the other, with an oscillating pellet between the two parts, which oscillating pellet serves to distribute the incoming compressed air either to drive the piston or to direct the air to a piston relief channel, thereby returning the piston to the upper position. Upon return of the piston to its upper position, the air is exhausted from the cylinder below the piston out to a muffling exhaust chamber, out to the atmosphere.

Abstract: A tool for driving fasteners includes a housing defining a handle portion and a nose portion. A driver is reciprocally mounted within the housing as is an assembly for driving the driver through a fastener driving stroke. A muffler is mounted in the housing adjacent and in fluid communication with the nose portion. The muffler includes a chamber defined within the housing and a tubular muffler element mounted within the chamber. The tubular muffler element includes a plurality of holes therein and communicates with at least one exhaust port. A second muffler element is mounted within the chamber and encircles the tubular muffler element.

Abstract: A compressed-gas-operated reciprocating-piston device, e.g. a concrete breaker, rock drill or chipping hammer, has a cylinder component of composite construction, comprising a rigid inner metal tube in which the piston reciprocates and a moulded outer sleeve of rubber or plastics material, e.g. polyurethane, which surrounds the tube over the majority of its length and is bonded thereto. The sleeve has three integral moulded longitudinal ribs in which are moulded longitudinal passages for transmission of compressed air to the cylinder interior. An outer tubular muffler of rubber or plastics material surrounds the composite cylinder component and defines a sound-reducing path for exhaust gas from the cylinder to thge atmosphere. The exhaust gas is discharged into spaces defined between adjacent ribs of the sleeve within the muffler, these spaces forming part of an expansion chamber in the muffler.

Abstract: A compressed-gas-operated reciprocating-piston device, e.g. a concrete breaker, rock drill or chipping hammer, has a cylinder component of composite construction, comprising a rigid inner metal tube in which the piston reciprocates and a moulded outer sleeve of rubber or plastics material, e.g. polyurethane, which surrounds the tube over the majority of its length and is bonded thereto. The sleeve has three integral moulded longitudinal ribs in which are moulded longitudinal passages for transmission of compressed air to the cylinder interior. An outer tubular muffler of rubber or plastics material surrounds the composite cylinder component and defines a sound-reducing path for exhaust gas from the cylinder to the atmosphere. The exhaust gas is discharged into two spaces defined between two pairs of adjacent ribs of the sleeve within the muffler, these two spaces forming part of an expansion chamber in the muffler.

Abstract: The invention relates to a product (1,9) of metal formed with a hole (5,8,17), particularly a rock drill steel, and provided with an element (10,12,14,15,16,18) for damping sound producing waves in the product annoying for the human ear. The sound damping element is arranged in the hole in the product and has a cross section less than the cross section of the hole. The damping element has at least one contact surface loosely arranged relative to the wall of the hole and located between the nodes of the waves so as to create at least one wave damping effect.

Abstract: A narrow profile power handle uniquely adapted for use as a flexible line trimmer having improved handling and safety features is disclosed. The power handle is also equipped with a quick connect and disconnect coupling and is useful for driving attachments to produce hand held rotary implements and tools such as brush cutters, edgers, cultivators, drills, etc., hand held reciprocating implements and tools such as hedge clippers, saws, etc., as well as portable water pumps, air compressors, generators, etc.The crankshaft of a two-stroke internal combustion engine is disposed along the longitudinal axis of a narrow profile housing which includes a rear handle having a hand grip portion disposed above and projecting rearwardly parallel to the axis of the housing. The cylinder extends upwardly from the crankcase, the carburetor is disposed below the crankcase, the flywheel, ignition system and starter to the rear, and the gas tank is disposed below the rear handle.

Abstract: An auger construction is provided which reduces the surface noise radiated by the auger and serves to at least partially isolate the auger from the remainder of the machine. The auger construction comprises an inner shaft and outer concentric shafts, the latter carrying the helical cutting blade and generally corresponding to the shaft of a conventional auger. An elongated annulus of noise and vibration dampening material is disposed between the inner and outer shafts. Preferably, the outer shaft is isolated from the machine by further noise dampening material disposed between the mounting flange and the proximate end of that shaft and between the free end of the inner shaft and the end of the hose in the outer shaft. A bore in the inner shaft is also filled with noise dampening material. A number of arrangements are disclosed for fixing the two shafts together so as to prevent rotational slippage therebetween.

Abstract: A hammer for breaking down strong abrasive materials comprising a body with a movable ram reciprocated by a drive and provided with a socket accommodating a tool intended to break down the materials by impacts during reciprocation of the ram. The end of the tool shank and the contacting bottom of the ram socket have the shape of matching spherical surfaces. The side surfaces of the tool shank and ram socket are separated by an elastic gasket and are made in the form of truncated cones whose larger base faces the working portion of the tool and angles of their cones are smaller than the angles of friction between the adjoining surfaces, the end of the working portion of the tool being provided with a blind hole which ensures better penetration of the tool into the material being broken.

Abstract: A pneumatic percussion rock drill includes a muffler casing surrounding the drill cylinder part and sealingly engaged with the drill housing so that exhaust air from the percussion motor flows forward through ports in a forward housing member into a chamber containing the drill chuck, the chuck rotation gearing, and the drill stem shank. Exhaust air is used to cool and lubricate the chuck parts before exiting from the drill onto the feed mechanism located below the drill housing.

Abstract: A rock drill for rotary blow drilling with a drilling head arranged at the free end of the drill shaft, which at least partially consists of hard metal. The drilling head the end face of which is circular disc shaped or circular ring shaped includes a formed piece of solid hard metal. Cutting bodies are machined out of the end of this piece of hard metal which cutting bodies have the shape of pyramids or truncated pyramids and taper with increasing distance from the drill shank.

Abstract: The air hammer is of the type employing a body having a first portion with a central bore and a piston reciprocable in the bore by pressurized air under control of an automatic valve. The body has a second or muffler portion which embraces the first portion and is operative to muffle the noise created by exhaust air from the bore. The muffler portion is provided with pressurized air passage means through which the pressurized air must pass for causing operation of the piston. The passage means are so arranged that removal of the muffler portion from the body disrupts the supply of pressurized air to the piston and thereby renders the hammer inoperative. Headers are provided on the ends of the body and are drawn tightly against the ends of the muffler portion by tie bolts which extend through through-passages, respectively, in the muffler portion.

Abstract: A vibration damper for an impact tool comprises a damping material which at least partly surrounds the working part of the tool, a heat shrinkable sleeve for holding the damping material in place on the working part of the tool.