Abstract: An acoustic filter adapted to be fitted on a pipe for the purpose of absorbing pressure waves. The acoustic filter has a body constituted by a cylinder, an inlet and outlet end, a locking ring fitted in a groove located at the inlet and outlet ends, coupling means within the locking rings for coupling the filter to a pipe. A holder tube fitted with diffuser rings for connecting the coupling means. A deformable bag made from a flexible material is mounted between the inlet and outlet ends, shaped like a cylindrical sleeve and surrounds the holder tube and diffuser rings. The bag defines with an inner wall of the cylinder a chamber for receiving a pressurized gas.

Abstract: A reciprocating piston and cylinder pneumatic motor with a sound-reducing system that diffuses exhausting air by directing it across the curved outer surface of the cylinder.

Abstract: A sound attenuator may be directly threadedly connected to the exhaust port of a pneumatic device whose exhaust air is to be attenuated. A fail safe blowout plug is provided in the attenuator at the end remote from the exhaust port connection. A cartridge screen covering exhaust slots in the attenuator wall is trapped within an annular groove in the end of the attenuator remote from the exhaust port connection. The screen overlies a protective cover within the attenuator which extends over the blowout plug.

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 noise suppressor for a pneumatic tool characterized by a plurality of annular or spiral suppression grooves on the inner wall of the body of pneumatic tool and a plurality of air being holes at the bottom of the suppression grooves on a side wall so that compressed air discharged can have its flow disturbed by impingement upon the suppression grooves and side wall and thus the time of discharge is prolonged and the noise from discharge of the compressed air is suppressed.

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: This invention is directed to a nozzle or spout for a sanitary fitting, which is arranged and constructed to reduce the noise of fluid, (water), as it flows through the nozzle or spout passageway and which also removes particles entrained in the fluid, (water), before flowing through the nozzle or spout passageways, to prevent clogging.

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: 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 soundproofing device for a drill which has an elongate shaft extending between a bit and a forged collar for attaching it to a pneumatic hammer comprises a sheath formed by a semi-rigid tube of plastics material adapted to surround the shaft without touching it. This sheath extends between sealed first mounting ring near the bit and second mounting ring near the hammer. These mounting ring are free to move relative to the shaft in rotation and in translation. Tests show a reduction in the noise level 5 m from the drill from 102 dBA to 89 dBA.

Abstract: Acoustic pulsations in fluid transmission systems such as gas pipelines, engine exhaust systems and compressed air networks are suppressed by an acoustic filter comprising an enlarged pressure vessel with inlet and outlet conduits arranged such that conduit inlet and outlet openings are at the pressure node of standing pressure waves of the pressure vessel length resonant frequency and odd or even harmonics of the fundamental frequency. The inlet and outlet conduit openings are arranged such that the direction of convection flow and acoustic pulsation modulating flow is transverse to the instantaneous particle velocity of fluid resulting from acoustic pulsations existing in or excitable in the pressure vessel. Inlet and outlet conduits preferably open into the pressure vessel in a generally radial direction with respect to the central longitudinal axis of the vessel.

Abstract: A connection block or adapter for joining up pneumatic components is made with an exhaust muffler to let off air from components into the outside atmosphere. The muffler is composed of a chamber inside the connection block and has a porous wall. The wall may be made in one piece with the connection block or bonded to it as a separate part. Preferred materials are load bearing foam resin for the connection block and metal frit for the wall of the muffler.

Abstract: A muffler for a pneumatic hammer of the type in which a cylinder receives a piston or ram which is pneumatically driven into contact with an anvil, e.g. the rear end of a tool, and in which the discharge of the air is muffled to limit the noise generated by the apparatus. The air to be discharged into the atmosphere is vented into an annular space between an outer wall of a sleeve or head surrounding the cylinder and connected by an elastic suspension thereto.

Abstract: A pneumatic servo booster including a housing, a power piston unit partitioning the interior of the housing into front and rear chambers and having therein a first passage with one end opening to the front chamber and the other end opening to the interior of the power piston unit and a second passage with one end opening to the rear chamber and the other end opening to the interior of the power piston unit, and a valve mechanism provided in the interior of the power piston unit and being associated with an input rod to control the communication between first and second passages and between the second passage and another passage which is communicated with a source of a first reference pressure. A plurality of diversion channels are provided in at least one of the first and second passages to decrease the speed of the air flow in the passage and to rectify the air flow thereby suppressing noise.

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: A fluid operated vacuum device for manipulating a workpiece includes a rectangularly shaped metal body having a plurality of fluid passageways therein. One passageway communicates with a suction cup for creating a vacuum between the cup and the workpiece. Another fluid passageway terminates in an exhaust opening on one end of the body over which there is secured a plastic muffler for dispersing and silencing fluid exiting from the body. The muffler is substantially hollow and includes a plurality of openings in one side thereof through which exhaust fluid may escape into the ambient atmosphere. The effectiveness of the muffler is increased by a recess in the body circumscribing the exhaust opening, a perforated baffle member within the muffler, and a series of dimples in an interior wall of the muffler upon which exhaust fluid impinges.

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: A muffler for use with pneumatically powered apparatus has a cylindrical housing with air outlet slots, to the back of which there is a pipe-like damper cartridge. Within the cartridge there is an axially adjustable choke body whose choke head is guided with a sliding fit by radial nosepieces resting against a support sleeve for the damper cartridge. A coned air flow controlling part of the choke head is used together with a coned face of the inner end of a connection inlet hole of the housing for forming an adjustable choke gap.

Abstract: Disclosed herein is a silencer constituted by a casing, open at the lower extremity made to communicate with the source of compressed gases, and closed at the top by a cover, inside which are placed, from the bottom upwards, a first element, a filter and a second element which, jointly with the inner surface of the casing, define a first, a second and a third expansion chamber, respectively, for the compressed gases.The first expansion chamber communicates with the open extremity of the casing, the second contains the aforementioned filter, while the third, via a slit made in the cover, communicates with the outside. The first and second expansion chamber are inter-communicating because of through holes drilled in the first element, and likewise the second and third expansion chamber are inter-communicating because of through holes drilled in the second element.

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 drill motor rigid enclosure is provided for a rock drill motor. The drill motor is encompassed within the enclosure such that viration, torque, and thrust produced by the motor is isolated from the rigid enclosure, therefore noise reduction of the drill motor is achieved.

Abstract: An apparatus is disclosed for receiving a high pressure fluid flow to accommodate a drop to a lower pressure fluid flow with attenuated noise, incorporating an initial diffuser stage followed by balance in-line stages so that each stage is subcritical to avoid shock noise. Specifically, an elongated tubular member is closed at one end and adapted to receive high pressure fluid flow at the opposed end. Perforations contiguous to the upstream end afford a diffuser stage of pressure reduction which is followed by concentrically mounted, perforated plates to accomplish staged pressure drops. Structurally, the elongate tubular member is fixed somewhat concentrically in a cylindrical housing along with a series of the perforated plates which are peripherally supported by the housing and centrally supported by the elongated tubular member.A diffuser as the first stage affords superior strength to withstand impacts and pressure loading.

Abstract: The sound absorber includes a main body (1), a housing component (2) attached thereon and a cap (3) threaded onto the main body. The compressed air exiting from the compressed-air vibrator flows from a first chamber (4) into a second chamber (5) provided with labyrinth-like baffles (7) and from there into a larger third chamber (6). The relieved compressed air then flows outside through an annular outlet slit (8a). Through rotation of the cap (3) there can be varied the cross-section of the outlet slit (8a). The cap (3) thereby also serves as a throttle valve.The sound absorber is insensitive to oil-containing compressed air and, without an auxiliary throttle valve, facilitates a correlatable throttle of the exiting compressed air.

Abstract: A compact low-resistance muffler for reducing sound levels generated by the pulsatile flow of fluids as, for example, at the intake of a compressor or the exhaust port of an internal combustion piston engine. The muffler or suppressor comprises a pair of adjacent branch passages having a common inlet trunk and a common outlet trunk, one of the branch passages containing a flow-restricting orifice and the other of such branch passages being free of any such restriction.

Abstract: A device for treating flowing working gases in order to reduce their operational noises and in most instances also to increase their operating efficiency comprises a flowing working gas operating device which has a discharge conduit with at least one discharge opening for the outflow of the working gas. A check valve is associated with the discharge and includes an elastic valve member movable to close the opening when the flow thereof decreases to a predetermined amount for example as determined by the reduction of pressure of the gases so as to prevent any back flow into the conduit which is likely to produce noise.

Abstract: A muffler assembly particularly adapted to silence the exhaust air from an air valve of an air system. The muffler is constructed so as to permit effective silencing without significantly increasing valve and/or system response times. In addition, the design provides long life by permitting the retention of foreign matter in the exhaust air without significantly increasing the restriction to flow or decreasing the performance of the muffler. The muffler includes an inlet, an expansion chamber, a packing of woven material and an exhaust opening in that sequence.

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: Silencers for gas discharge devices employing easily replaceable cartridges utilizing juxtapositioned layers of wire mesh and porous absorbed material which dissipate exhaust noises of an exhaust system and deflect under pressure of the exhaust gases to provide a self cleaning function.

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: A sound absorber or silencor for sound from outlets of air or gas comprising a tube or flexible hose (2) which is connected to an outlet (1) of air or gas and which contains a sound absorbing body (3), whereby the tube or hose (2) and the sound absorbing body (3) can move more or less freely in relation to each other and/or in which the tube or hose (2) together with the sound absorbing body (3) is made easily flexible. Preferably both the outer hose (2) and the sound absorbing body are flexible and the sound absorbing body is movable inside the hose (2). The sound body (3) can be a strong, threads, fibres, loops etc. of plastic, metal, natural fibres or similar material.

Abstract: A muffler for use with machines such as pneumatic drills consists of an elastomeric housing divided into an admission chamber and a series of muffler chambers. Within the housing are an inlet conduit communicating with the admission chamber and each muffler chamber, an exhaust conduit communicating with each muffler chamber as well as with a tail pipe outside the housing, and a Helmholtz resonator communicating with the admission chamber.

Abstract: A dust-boot for a vacuum booster, which is partly protruded into the driver's room, characterized in being provided with a noise preventing wall firmly formed in such a mode, that it covers the air-sucking hole(s) to prevent the air-sucking noise from directly reaching the driver's ears, through the formation of an air flowing passage between the wall and the outer surface of the dust-boot main body, which air flowing passage is different in the direction of the air flow from that at the air-sucking hole(s) and bent or wound at least once on the way.

Abstract: A tool handle construction incorporating a unitary inlet-exhaust assembly, allowing economies of construction.

Abstract: A muffler construction, particularly for exhaust gases of air-operated tools, comprises, a tubular sleeve having a passage therethrough, an exhaust gas pipe connected into the sleeve and defining a restricted flow passage with the sleeve, first and second opposed cylindrical coaxial shell sections, each having a closed end wall at their respective outer ends and facing in opposite directions engaged with the exhaust gas pipe, and sidewalls spaced radially outwardly from the sleeve. The exhaust gas pipe has a gas pipe discharge and there are partition walls in the shell sections defining a first expansion chamber and at least one additional expansion chamber. A constricted flow passage is defined between the first expansion chamber and the at least one additional expansion chamber with sealing and enclosing members closing the sidewalls of the first and second shell sections so as to define the first expansion chamber and at least one additional expansion chamber within the shell sections.

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: The present invention relates to a novel outlet air muffler for air-powered transportable driving tools such as nailers. The muffler includes an outlet air duct formed in a housing endpiece and the top lid of the nailer. The outlet air duct is made up of two like chamber systems whose chambers are joined together by wall hollows. The chambers are furthermore interconnected through holes leading from the outlet side of the main control valve.

Abstract: Exhaust air from an air tool or other air actuated device is directed into an air expansion chamber separated by slots from a second chamber containing a predetermined volume of small unconnected particles, such as small pellets of reground plastic scrap material. The plastic pellets or particles loosely fill the second chamber so that each particle is free to move in response to air flow between the particles so that the particles are self-cleaning. In the embodiment illustrated, all of the components of the muffler are formed of a plastics material, and a threaded tubular portion provides for attaching the muffler to an air actuated device.

Abstract: A sound absorber for intermittent exhaust gas, particularly for use in connection with a compressed air operated motor employed, for example, in a hand grinder. The sound absorber is arranged predominantly in the housing of the motor and includes an exhaust air discharging channel having an alternately varying cross-section to define a succession of continuously alternating narrow and wide passages for changing continuously the direction of flow of the exhaust air about an angle that is always lower than 90.degree. with respect to the axis of the discharge channel so that the ratio of successive minimum and maximum cross-sections of the channel is at most 4:1. The discharge channel is terminated with a nozzle plate defining a plurality of outlet nozzles the central axes of which converge in the direction of flow.

Abstract: The invention relates to a muffler for portable pneumatic tools wherein the exhaust of the pneumatic motor is passed into an expansion chamber having a perforated outlet baffle biased to the direction of the flow in the chamber. The flow from the expansion chamber enters a muffler chamber having an outlet baffle also biased to the direction of fluid flow. Both the first and second baffle are formed in an end cap for the handle of the pneumatic tool and form a removable extension thereof.

Abstract: A combination muffler and air filter is provided having a central tubular member with spaced longitudinally disposed elongated slots. A disposable canister on the central tubular member is removably held in position by retainer caps engaged on the ends of the central tubular member. One of the retainer caps is adapted for connection to the exhaust conductor from a pneumatically operated device. The disposable canister has a perforated cylinder encasing a series of stacked annular members having both muffling and filtering properties. A perforated sleeve in the disposable canister supportively engages the inner periphery of the stacked annular members. A closure disc, fixed on each end of the perforated cylinder, holds the stacked annular members in a compact and compressed condition.

Abstract: An exhaust muffler intended for noise dampening of, for instance, pneumatic tools, comprising a variable flow restricting passage, an attenuation chamber and a non-variable flow restricting passage. A valve body is arranged to control said variable flow restricting passage in response to the actual exhaust gas pressure. A movement dampening chamber, partly defined by the valve body, communicates with the atmosphere through a restriction opening to prevent resonance vibration of the valve body.

Abstract: A muffler is integrally incorporated with a pneumatic tool by cooperating with the tool housing intermediate the air exhaust chamber for the air motor and atmosphere. An inwardly dished muffler shell includes an exhaust inlet for receipt of exhaust air from the air motor. The shell is selectively positionable and may be combined with screen and additional muffler material as well as a retaining plate in any of a number of combinations to provide distinctive muffling characteristics for the air tool.

Abstract: A combination muffler and air filter, having a central tubular member with spaced longitudinally disposed elongated slots. A disposable canister on the central tubular member is removably held in position by retainer caps engaged on the ends of the central tubular member. One of the retainer caps is adapted for connection to the exhaust conductor from a pneumatically operated device or compressed air system. The other retainer cap has therein an annular sump, connected by lateral ducts to a drain opening. The disposable canister has a perforated cylinder encasing a series of stacked annular members having both muffling and filtering properties. A perforated sleeve in the disposable canister supportively engages the inner periphery of the stacked annular members. A closure disc, fixed on each of the perforated cylinders, holds the stacked annular members in a compact and compressed condition.

Abstract: The air muffler is primarily designed to be carried by a snug fitting hood respirator adapted to fit over the head of a person and to dispense breathable air into the hood in a minimum quantity of at least four cubic feet per minute, with a controlled noise level not to exceed 80 decibels, and with varying air pressure of from 11 to 25 pounds per square inch. The muffler utilizes a non-absorbent porous resilient fibrous filter media within a tubular casing provided with a series of ports, with the casing located entirely within a bag made from a non-absorbent porous fibrous material. An air pocket is provided between the portion of the casing provided with the ports and the bag. The air is directed from the source through the casing where it is restricted as it passes through the non-absorbent porous filter media prior to escaping through the ports in the casing into the air pocket where the air is muffled and is finally discharged into the hood through the porous fibrous bag.

Abstract: A noise reduction device for use with an impact tool which comprises a deformable block having a flat face and an opening therein for accepting the set of the tool, and a cylindrical housing extending from the block and sealed about the tool, with an open conduit extending from said housing.

Abstract: A unitary, elastic muffler assembly includes an arcuate, channel-shaped, sound-muffling section having opposite ends bridged by an integral elastic band. The assembly is telescoped over the tubular housing of a pneumatic device into a position to receive spent working fluid exiting from housing vents into the central area of the sound-muffling section wherein the fluid divides and follows arcuate flow paths defined by the tubular housing and the sound-muffling section through sound-attenuating material to exhaust ports located in the end walls of the sound-muffling section. The movement of the fluid along the defined flow paths of a total arcuate extent substantially greater than 90.degree. diminishes the noise level of the spent working fluid below 90 dBAs. Also, the fluid movement away from the housing vents avoids causing icing up or significant reducing of the operating efficiency of the pneumatic device.

Abstract: An `in-line` unit for use in compressor station piping, arranged to reduce the level of noise generated when the blowdown valves of the station piping are opened in an emergency to vent the high pressure gas therein to atmosphere, the unit comprising a pipe section having a plurality of orifice plates the number and hole area of which is designed to ensure sub-sonic flow through each plate. The unit is preferably used in combination with a modified form of silencer element connected `in-line` downstream thereof.

Abstract: A noise attenuator or muffler for a compressed air tube type heater is disclosed. The muffler exhaust air through exit apertures located about its periphery and due to its unique design substantially avoids the formation of ice in the muffler.

Abstract: A rock drilling apparatus has a noise reducing drill rod cover which comprises a pair of elongated strips, each of which, when in an extended condition in the longitudinal direction thereof, form part-cylindrical members which matingly engage the other strip to form a generally cylindrical cover around the drill rod. Spool means is provided, preferably in the area of the centralizer, to selectively roll the elongated strips thereon, the strips being flattened when rolled onto the spool means. The elongated strips are rolled onto simultaneously driven spools, and comprise either metallic strips, metallic strips covered with rubber on one or both surfaces thereof, or elastic strips having spaced metallic inserts embedded therein.