US3255844A - Multi-passage silencer for pneumatic tool - Google Patents

Multi-passage silencer for pneumatic tool Download PDF

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Publication number
US3255844A
US3255844A US338037A US33803764A US3255844A US 3255844 A US3255844 A US 3255844A US 338037 A US338037 A US 338037A US 33803764 A US33803764 A US 33803764A US 3255844 A US3255844 A US 3255844A
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Prior art keywords
chamber
silencer
exhaust
plates
passage
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US338037A
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English (en)
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Arthur W Wallace
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Gardner Denver Inc
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Gardner Denver Inc
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Priority to US338037A priority Critical patent/US3255844A/en
Priority to GB50932/64A priority patent/GB1075520A/en
Priority to AT865A priority patent/AT269011B/de
Priority to CH15065A priority patent/CH424676A/fr
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    • E—FIXED CONSTRUCTIONS
    • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
    • E01C—CONSTRUCTION OF, OR SURFACES FOR, ROADS, SPORTS GROUNDS, OR THE LIKE; MACHINES OR AUXILIARY TOOLS FOR CONSTRUCTION OR REPAIR
    • E01C19/00—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving
    • E01C19/22—Machines, tools or auxiliary devices for preparing or distributing paving materials, for working the placed materials, or for forming, consolidating, or finishing the paving for consolidating or finishing laid-down unset materials
    • E01C19/30—Tamping or vibrating apparatus other than rollers ; Devices for ramming individual paving elements
    • E01C19/34—Power-driven rammers or tampers, e.g. air-hammer impacted shoes for ramming stone-sett paving; Hand-actuated ramming or tamping machines, e.g. tampers with manually hoisted dropping weight
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25D—PERCUSSIVE TOOLS
    • B25D17/00—Details of, or accessories for, portable power-driven percussive tools
    • B25D17/11—Arrangements of noise-damping means
    • B25D17/12—Arrangements of noise-damping means of exhaust silencers
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S173/00—Tool driving or impacting
    • Y10S173/02—Sound muffling

Definitions

  • An object of this invention is to effectively suppress the sound Waves induced .by the emission of exhaust air from an air motor, such as a piston type air motor in a rock drill.
  • Another object of this invention is to provide one or more mufiiing devices, each for suppressing sound waves in a selected frequency range of the total sound spectrum induced by the exhaust air from a motor.
  • FIG. 1 is a longitudinal sectional view of a portion of a pneumatic tool casing including a motor chamber for a reciprocating piston hammer, and including muffiing devices communicating with the exhaust passage from the motor chamber.
  • FIG. 2 is a view of the assembly of FIG. 1, partially in section as viewed along the line 2-2 of FIG. 1 looking in the direction of the appended arrows.
  • FIG. 3 is a partial transverse sectional view, as viewed along the line 33 of FIG. 1.
  • FIG. 4 is a partial transverse section-a1 view, as viewed along the line 44 of FIG. 1.
  • FIG. 5 is a partial transverse sectional view, as viewed along the line 5-5 of FIG. 1.
  • FIG. 6 is a longitudinal sectional view of a portion of a pneumatic tool casing including a motor chamber for a reciprocating piston hammer, and including another arrangement of muflling devices communicating with the exhaust passage from the motor chamber.
  • FIG. 7 is a partialtransverse sectional view, as viewed along the line 7-7 of FIG. 6.
  • FIG. 8 is a fragmentary sectional view, as viewed along the line 88 of FIG. 7.
  • FIG. 9 is a partial transverse sectional view, as viewed along the line 9-9 of FIG. 6.
  • FIG. 10 is a partial transverse sectional view, as viewed along the line 10-10 of FIG. 6.
  • FIG.-l1 is a fragmentarysectional view, as viewed along the line 1111 of FIG. 6.
  • FIG. 12 is a longitudinal sectional view of a portion of a pneumatic tool casing having a motor chamber for a reciprocating piston hammer, and including still another arrangement of mufiling devices communicating with the exhaust passage from the motor chamber.
  • FIG. 13 is a partial transverse sectional view, as viewed along the line 13- 13 of FIG. 12.
  • FIG. 14 is a partial transverse sectional view, as viewed along the line 1414 of FIG. 12;
  • FIG. 15 is a partial transverse sectional view, as viewed along the line 1'5-15 of FIG. 12.
  • noise of considerable intensity is created over substantially the entire audible frequency range.
  • Some of the noise is mechanical noise created by the striking together and vibration of the mechanical parts i of the drill; and some of the noise is produced by sound pressure waves induced by. the air exhausted by the drill during its operation.
  • noise is produced by the puffs of air which are exhausted from the hammer chamber at the end of the power stroke and return stroke of the piston hammer.
  • the frequency of these puffs may be in the range of 60 to cycles per second; however, it has been observed that sound pressure waves induced at the harmonics of these frequencies are considerably more intense than the sound waves at the fundamental frequency.
  • the rock drill includes a casing portion 1 and a back head portion 2, mounted at the rearward end of the casing.
  • the internal bore of the casing 1 is larger at its rearward end and defines a chamber 3, adjacent to the back head, for
  • the forward end of the casing bore defines a cylinder chamber 4 for a piston hammer 5 having an enlarged head and a forwardly extending stem 6, the stem 6 extending slidably through a cylinder bushing and liner assembly 7 to strike a working implement.
  • the casing 1 includes external longitudinally extending ribs 8 which enclose the usual air passages for controlling the operation of the drill.
  • An internal annular groove 9 is provided intermediate the ends of the cylinder chamber 4 and positioned to be exposed by the head of hammer 5 after each ofthe power and return strokes.
  • a partial annular rib 10 is provided on the exterior of the casing and is disposed generally in the plane of the annular groove 9.
  • Three pasages 11 extend through the rib 10 in a direction transverse to the plane of the groove 9; and these pasa-ges are communi-' cated with the annular groove by means of a milled slot -12 which is cut into the rib 10 from the groove, in the plane of the groove. It will be seen then that the annular groove 9, the milled slot 12 and the passages 11 define exhaust ports opening from the cylinder chamber 4 to exhaust the air from the chamber at the end of each of the power and return strokes of the hammer.
  • An elongated box-like housing 13 is mounted along one side of the casing enclosing the partial annular rib 10.
  • the housing comprises parallel side walls 14, an outer wall 15 bridging the side walls 14, and an end wall 16 sealing the housing at the forward end thereof.
  • Trvo transverse partitions 17 and 18 divide the housing into three separate and adjacent chambers.
  • the partition 17 is joined to the rib and defines, with the end wall 16, a forward chamber 19 open to the forward ends of the passages 11.
  • the partition 18 is spaced rearward of the partition 17 and defines with the partition 17 an intermediate chamber 20 open to the rearward ends of the passages 11.
  • This partition also defines the rearward chamber 21 which is open to ambient atmosphere at its rearward end as will be described.
  • Three holes 22 in the partition 1 8 communicate the chambers 20 and 21.
  • side walls 14 and the outer wall 15 extend rearw-ardly be yond the casing 1 and overlies the back head 2.
  • the sidewalls 14 are provided with notches 24 which define lateral openings from the hous- .ing chamber 21 between the sidewalls and the back head. The rearward end of the chamber 21 is partially closed as will be described subsequently.
  • the forward chamber 19 is completely sealed except for communication with the forward ends of the passages Therefore, the main flow of air from the cylinder chamber does not pass into the chamber 1? but flows by the opening to the chamber.
  • This chamber defines a resonating chamber of the side branch type which is activated by the air flowing past the chamber opening.
  • the air flowing past the chamber opening contains sound pressure waves over a range of frequencies and these pressure waves are transmitted to the air within the resonating chamber.
  • the chamber produces counterpressure waves at its resonant frequency and is efi'ective to cancel or damp out the activating waves of the exhaust air. It has been observed that this dampening effect is significant not only at the precise tuned frequency, but is also effective over a relatively broad range of frequencies on either side of the tuned frequency. It has been found that a resonating chamber of this type, tuned to a frequency in the area of 400 to 500 cycles per second produces a significant reduction in the noise produced by a rock drill in the lower end of the frequency spectrum.
  • the exhaust air flows through the chamber 20, entering the chamber from the passages 11 and leaving the chamber through the holes 22.
  • the combined area of the holes 22 is substantially the same as the combined area of the passages 11 so that the air flowing into this chamber may expand but must be trecompressed before passing into the chamber 21.
  • the chamber 20 defines an expansion chamber resonator which, being smaller than the chamber 19, is tuned to a higher frequency.
  • This expansion chamber resonator functions in a manner similar to the side branch resonator chamber 19 in that it produces counterpressure waves at the tuned frequency which cancel the pressure waves at that frequency induced by the air flowing through the chamber; and this produces additional noise reduction in the area of the tuned frequency.
  • a silencer 27 is mounted within the housing chamber I 21, adjacent to the partition 18.
  • This silencer consists of an assembly of thin rectangular plates 28, all of identical configuration, stacked in uniformly spaced relation to each other.
  • the plates are assembled on a bracket 29 consisting of a plate having four transverse, parallel rods 30 projecting therefrom.
  • Each of the silencer plates 28 is provided with suitable holes for receiving the rods 30, and the plates may be spaced from each other by means of suitable washers placed over the rods and between the adjacent plates.
  • Each of the plates 23 and the bracket plate 29 is provided with three large holes 31, located respectively in the center and adjacent to the two ends of the plate; and two smaller holes 32 located between the holes 31.
  • the partition 18 is provided with four holes to receive the ends of the bracket rods 30, and the bracket plate 29 is provided with flanges which are secured to the side walls 14, by means of bolts or rivets for example.
  • the plates 28 are then confined in a stacked relation between the partition 18 and the bracket plate 29.
  • the holes 31 in the silencer plates 28 and in the bracket plate 29 are aligned with each other and with respective holes 22 in the partition 18, as best seen in FIGS. 2, to define unobstructed flow paths through the silencer for the air entering the chamber 21 through the holes 22.
  • the silencer 27 does not fully occupy the space within the chamber 21; and the air flowing through the flow paths defined by the holes 31 is permitted to expand laterally between the plates to the exterior of the silencer asssembly. This expanding air also enters the chambers or flow paths defined by the holes 32 in the silencer plates 28 and in the bracket plate 29 so that some of the expanding air may flow forwardly through these flow paths. Due to the expansion of air laterally through the spaces between the silencer plates, the velocity of air in the main flow paths through the holes 31 is reduced as the air moves through the silencer assembly thereby reducing the jet noise induced in the air flowing from the chamber 20 and into the chamber 21 through the silencer 27.
  • a silencer as above described, which has proved effective in reducing noise above 1,000 cycles per second, has been fabricated of nylon plates having a thickness of inch and spaced inch apart.
  • a generally wedged shaped, sound absorbing deflector 35 is mounted at the rearward end of the housing 13, partially closing the rearward end of the housing chamber 21, as best seen in FIGS. 1 and 5.
  • This deflector is preferably constructed of a porous, sound-absorbing material, such as felt, and may be secured in the housing by cementing the deflector to the side walls and outer wall of the housing.
  • the deflector presents a surface 36 which is inclined relative to the flow of air from the main flow paths through the silencer defined by the holes 31.
  • the air, impinging on the surface 36 is deflected generally toward the adjacent wall of the back head 2 and flows out of the chamber 21 through the openings defined by the notches 24 in the side walls 14 to ambient atmosphere. While the exhaust air itself is deflected from the linear paths through the silencer 27, high frequency sound waves in this air stream do not deflect but pass into the sound absorbant body and are absorbed therein to eifectively reduce noise of the air passing from the chamber 21.
  • FIGS. 6 through 11 there is shown another muffiing arrangement for a conventional type of rock drill.
  • a casing portion 41 defining a cylinder chamber 42 at its forward end and a larger chamber 43 at its rearward end for a conventional valve block and distribution valve.
  • a piston hammer 44 reciprocates within the cylinder chamber 43, and a forwardly extending reduced diameter stem 45 of the hammer is guided in a cylinder bushing and liner 46 mounted at the forward end of the casing 41.
  • Longitudinal ribs 47 along the outside of the casing 41 enclose the usual air passages for controlling the rock drill.
  • the casing 41 is provided with an internal annular groove 49 intermediate the ends of the cylinder chamber 42. This groove is positioned to be exposed by both faces of the hammer, respectively, at the ends of forward and return strokes of the hammer.
  • an external annular rib 50 extends partially around the casing 41, in the plane of the groove 49, and is provided with two arcuately shaped passages 51 which pass generally longitudinally through the rib 50.
  • a milled slot 52 is cut into the rib 50 from the annular groove 49, in the plane of the groove, to communicate the annular groove with the passages 51.
  • the exhaust air flowing from the chamber 42 then, passes radially through the slots 52 into the passages 51.
  • the passages 51 are slightly inclined so that the air flowingfrom the slots 52 impinges on walls of these ports which are not perpendicular to, the direction of air flow from the slots 52.
  • a longitudinally extending box-like housing 54 is mounted on the outside of the casing 41 along one side thereof, enclosing the annular rib 50.
  • the housing is defined by side walls 55, an outer wall 56, an end wall 57 at the rearward end thereof, and an end wall at the forward end defined by an extension of cylinder bushing 46.
  • the side walls and the end wall 56 are secured to the casing by means of welding, for example; the side walls being secured to the longitudinal ribs 47, the inner edges of the side walls being indicated by the dotted line 58 in FIG. 6.
  • a transverse partition 59 is joined to the rib 50, and divides the housing 54 into a rearward chamber 60 and a forward chamber 61.
  • the side walls 55 are provided with notches 62 at the forward ends, as best shown in FIG. 6, to define exhaust openings from the forward chamber 61.
  • the rearward chamber 60 is sealed except for the communication with the rearward ends of the passages 51, as best seen in FIG. 8; and this chamber defines a side branch resonating chamber for the exhaust air which-flows from the cylinder chamber 42 through the milled slots 52 and the passages 51 into the forward chamber 61.
  • the resonating chamber 60 is tuned to a relatively low frequency, in the range of 400 to 500 cycles per second, for example, to damp sound waves at frequencies which are produced by harmonics of the puffs of the exhaust air passing from the cylinder chamber 42.
  • a silencer 63 is mounted in the forward chamber 61 adjacent to the forward wall of the rib 50.
  • the silencer 63 consists of an assembly of thin plates 64 generally in the shape of a half-moon, which are stacked in uniformly spaced relation to each other on a bracket 65.
  • the bracket 65 includes a plate having a configuration similar to that of the plates 64 and three transversely extending rods.
  • center rod 66 extends transversely through the bracket plate 65 and two outer rods 67 extend rearwardly from the ends of the bracket plate parallel to the center rod.
  • the silencer plates 64 are each provided with a center hole and two end holes to accommodate the rods 66 and 67, and the plates are assembled on the rods in spaced relation, for example, by means of suitable washers interposed between the adjacent plates. As best shown in FIG. 10, the plates 64 are each provided with two arcuate openings 68 respectively between the holes for the bracket rods.
  • the bracket 65 is provided with similar arcuate holes which are aligned with the holes 68 to provide linear flow paths through the silencer assembly.
  • the silencer is mounted in the chamber 61 against the forward wall of the rib 50; and for this purpose, the rib 50 is provided with three holes positioned relative to the arcuate openings of the passages 51, as best seen in FIG. 9, to receive the rearward ends of the bracket rods 66 and 67 to align the holes 68 in the silencer plates with the passages 51.
  • the bracket rod 66 extends forwardly from the bracket plate 65 and bears against the forward wall of the housing 54 defined by the cylinder bushing 46.
  • This forwardly extending portion of the bracket rod 66 passes through and is supported by a deflector 71 which is secured in the forward end of the chamber 61 as by cementing, for example.
  • the deflect-or 7-1 is V-shape'd in configuration and presents two surfaces 72 which are inclined relative to the direction of air flow from the silencer flow paths defined by the holes 68, and are disposed to the air laterally toward openings 62 in the side walls 55.
  • the deflector 711 comprises a body of porous material, such as felt, for the purpose of deflecting the air toward the exhaust openings from the chamber 61, while absorbing high frequency sound waves in the air impinging against the deflector surfaces 72.
  • the silencer 63 does not fully occupy the chamber 61, so that some of the air flow ing through the main flow paths defined by the plate holes 68 may expand laterally through the spaces between 6 the plates 64 and then pass from the chamber 61 to the ambient atmosphere through the exhaust openings 62.
  • FIGS. 12 through 15 there is shown still another muffling arangement for a conventional type of rock drill.
  • a casing portion 74 defining a cylinder chamber 75 at its forward end, for a reciprocating piston hammer 76, and a larger chamber 77 at its rearward end, for a valve block and distribution valve.
  • the torwardly extending stem of the hammer is guided in a cylinder bushing and liner assembly 78.
  • the casing includes longitudinal ribs for carrying necessary air passages.
  • An internal annular groove 79 is provided intermediate the ends of the cylinder chamber 75 and positioned to be exposed by the head of the piston hammer 76 after each of the power and return strokes.
  • Five exhaust ports 80 are provided at one side of the casing 74, opening from the annular groove 79 to the exterior of the casing. These ports, in cooperation with the annular groove, de fine the exhaust openings from the cylinder chamber 75 which are opened at the end of each of the power and return strokes of the hammer.
  • An elongated box-like housing 82 is mounted on one side of the casing, enclosing the exhaust ports 80.
  • This housing consists of parallel side walls 83 which are joined to the casing along a portion of its length as indicated by the dotted line 84 in FIG. 12, an outer wall 85 bridging the side walls, and an end wall 86 closing the housing at its rearward end.
  • the housing 82 is coextensive in length with the casing portion 74; and the housing is provided with a transverse partition 87 intermediate its ends which divides the housing into a rearward chamber 88 and a forward chamber 89.
  • the partition 77 is positioned forward of the exhaust ports 80 so that the exhaust ports open into the rearward chamber.
  • the partition 87 is provided with three spaced holes 90 which communicate the two chambers 88 and 89.
  • the side walls 83 are not joined to the casing along their entire length, but are provided with notches 91 at their forward ends, as indicated :by the dotted lines in FIG. 12, to define lateral openings from the chamber 89 at the forward end thereof.
  • the forward end of the forward chamber 89 is partially closed as will be described subsequently.
  • the pulfs of exhaust air from the cylinder chamber 75 are exhausted through the exhaust ports 80 directly into the rearward chamber 88, and this air is then discharged from the chamber 88 through the holes 90 in the partition 87.
  • the chaimlber '88 is dimensioned to define an expansion type resonating chamber tuned to absorb sound waves at .the lower end of the frequency spectrum which are created by the pufls of exhaust air discharging into the chamber.
  • the total area of the holes 90 is substantially the same as the total area of the exhaust ports 80 so that the air entering the chamber 88 is expanded and then must be recompressed before discharging through the holes 90.
  • a silencer 92 is mounted within the forward chamber 89 adjacent to the forward wall of the partition 87; and this silencer has the same structure as the silencer 27 described with reference to FIGS. 1 through 5.
  • This silencer consists of an assembly of thin rectangular plates 93, all of identical configuration, stacked in uniformly spaced relation to each other. The plates are assembled on a bracket 94 consisting of a plate having four transversely projecting parallel rods 95.
  • Each of the silencer plates 93 is provided with suitable holes for receiving rods 95, and the plates may be spaced from each other by suitable washers placed over the rods and between the adjacent plates.
  • Each of the plates 93 and the bracket plate 94 is provided with three large holes 96, located respectively in the center and adjacent to the two ends of the plate, and two smaller holes 97 located between the holes 96.
  • the partition 87 is provided with and the bracket plate 94 is provided with flanges which are secured to the side walls 83, by means of bolts or rivets for example. The plates are then confined in stacked relation between the partition 87 and the bracket plate 94.
  • the holes 96 in :the silencer plates 92 and in the bracket plate 93 are aligned with each other and with respective holes 90 in the partition 87 to define unobstructed flow paths through the silencer for the air entering the chamber 89 from the chamber 88 through the holes 90.
  • the silencer 92 does not fully occupy the. space within the chamber 89; and the air flowing through the flow paths defined by the holes 96 is permitted to expand radially between the silencer plates and to pass to the exterior of the silencer assembly. This expanding air also may enter the chambers or flow paths defined by the holes 97 in the silencer plates and the bracket plate, so that some of the expanding air may flow forwardly through these flow paths.
  • a generally wedge-shaped, sound absorbing deflector 88 is mounted at the forward end of the housing 82, partially closing the forward end of the chamber 89, as best seen in FIGS. 12 and 15.
  • the deflector 88 is preferably constructed of a porous, sound absorbing material, such as felt, and may be secured in the housing by cementing the deflector to the side walls and outer wall of the housing.
  • the deflector 98 presents a surface 99 which is inclined relative to the flow of air issuing through the main flow paths through the silencer 92 defined by the holes 96 in the silencer plates. This air, impinging on the surface 99, is deflected generally toward the adjacent exterior Wall of the casing 74 and flows out of the chamber 89 through the openings, defined by the notches 91 in the side walls 83, to ambient atmosphere.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining first, second and third chambers, a first passage communicating said first and second chambers, a second passage communicating said second and third chambers, and an opening from said third chamber to ambient atmosphere; said exhaust port communicating with said first passage;
  • said first chamber being open only to said first passage, and thereby being open to the florw of exhaust air through said exhaust port and said first passage to define a side branch resonator for damping sound waves of a selected frequency range in the exhaust air;
  • said second chamber defining an expansion chamber resonator for damping sound waves of a selected frequency range in the exhaust air flowing into the chamber through said first passage and out of said chamber through said second passage;
  • a silencer for sound waves of a selected frequency range mounted in said third chamber adjacent to said second passage; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and with said second passage to define a main flow path through said silencer for the exhaust air flowing from said second passage; the spaces between said plates defining auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer;
  • a sound [absorbing deflector mounted in said third chamber adjacent to said silencer in registry with said silencer main flow path; said deflector presenting a surface inclined relative to said silencer main flow path and disposed to direct the flow of air from said main flow path to said opening from said third chamber; and said deflector comprising a porous body for absorbing sound waves in the air impinging against said inclined surface.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber; means on said casing defining a resonator chamber and a passage communicating said resonator chamber with ambient atmosphere; said resonator chamber cominunicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said motor chamber;
  • a silencer mounted in communication with said passage for damping high frequency sound waves in the air flowing through said passage;
  • said silencer comprising means defining an unobstructed passageway providing a main flow path for the exhaust air flowing from said resonator chamber, the walls of said passageway having openings therethrough defining auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer;
  • sound absorbing deflector means mounted in the main flow path of air flowing through said silencer to present a surface inclined to said main flow path; and said deflector means comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining resonator chamber, and a passage communicating said resonator chamber with ambient atmosphere; said resonator chamber communicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said piston chamber;
  • a silencer for high frequency sound waves mounted on said casing adjacent to said passage; said silencer comprising an assembly of thin plates stacked in spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and with said passage to define a main flow path through said silencer for the exhaust air flowing from said passage; the spaces between said plates defining auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer;
  • a sound absorbing deflector mounted on said casing adjacent to said silencer, in registry with the silencer main flow path; said deflector presenting a surface inclined relative to said silencer main flow path to deflect the flow of air from said main flow path; and said deflector comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining first and second chambers, a passage communicating said chambers, and an opening from said second chamber to ambient atmosphere; said first chamber communicating with said exhaust port and being dimensioned to define a resonator chamber for damping low frequency sound waves in the exhaustair flowing from said piston chamber;
  • a silencer for high frequency sound waves mounted in said second chamber adjacent to said passage;
  • said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and with said passage to define a main flow path through said silencer for the exhaust air flowing from said passage; the spaces between said plates defining auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer;
  • a sound absorbing deflector mounted in said second chamber adjacent to said silencer, in registry with said silencer main flow path; said deflector presenting a surface inclined relative to said silencer main flow path and disposed to direct the flow of air from said main flow path to said opening from said second chamber; and said deflector comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber; means on said casing defining a resonator chamber, and a passage communicating said resonator chamber with ambient atmosphere; said resonator chamber communicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said motor chamber;
  • a silencer mounted in communication with said passage for damping high frequency sound waves in the air flowing through said passage; said silencer comprising a structure defining an elongated, unobstructed passageway providing a main flow path and outlet for the exhaust air flowing from said resonator chamber; and said structure defining numerous auxiliary passageways opening from said unobstructed passageway throughout its length to auxiliary outlets, providing auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining a resonator chamber, and a passage communicating said resonator chamber with ambient atmosphere; said resonator chamber communicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said piston chamber;
  • a silencer for high frequency sound waves mounted on said casing adjacent to said passage; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of 'said plates registering with each other and with said passage to define a main flow path through said si lencer and a main outlet for the exhaust air flowing from said passage; and the spaces between said plates defining auxiliary flow paths-from said main flow path and auxiliary outlets for the exhaust air flowing through said silencer.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining firs-t and second chambers, a passage communicating said chambers, and an open- -ing from said second chamber to ambient atmosphere; said first chamber communicating with said exhaust port and being dimensioned to define a reson-ator chamber for damping low frequency sound waves in the exhaust air flowing from said piston chamber;
  • a silencer for high frequency sound waves mounted in said second chamber adjacent to said passage; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and with said passage; .said plate openings defining a main flow path through said silencer and a main outlet for the exhaust air flowing from said passage; and the spaces between said plates defining auxiliary flow paths from said main flow path and auxiliary outlets for the exhaust air flowing through said silencer.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber; means on said casing defining a resonator chamber, and a passage communicating said chamber with ambient atmosphere; said resonator chamber communicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said motor chamber;
  • sound absorbing deflector means mounted on said cas ing in the path of the air flowing through said passage to present a surface inclined relative to said path; and said deflector comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining resonator chamber, and a passage communicating said chamber with ambient atmosphere; said resonator chamber communicating with said exhaust port and being dimensioned for damping low frequency sound waves in the exhaust air flowing from said piston chamber;
  • a sound absorbing deflector mounted on said casing in registry with said passage; said deflector presenting a surface inclined relative to said passage to deflect the flow of air from said passage; and said deflector comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a piston chamber and an exhaust port opening from said piston chamber; means on said casing defining first and second chambers, a passage communicating said chambers, and an opening from said second chamber to ambient atmosphere; said first chamber communicating with said exhaust port and being dimensioned to define a resonator chamber for damping low frequency sound waves in the exhaust air flowing from said piston chamber;
  • the combination of sound absorbing deflector means mounted in the main flow path of air flowing through said silencer to present a surface inclined relative to said main flow path; and said deflector means comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber; means on said casing defining an exhaust chamber communicating with said exhaust port, and an opening from said chamber to ambient atmosphere;
  • silencer mounted in said exhaust chamber adjacent to said exhaust port for damping sound waves in the exhaust air flowing from said motor chamber; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and said exhaust port to define a main flow path through said silencer for the exhaust air flowing from said exhaust port; the spaces between said plates defining auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer;
  • sound absorbing deflector mounted in said exhaust chamber adjacent to said silencer, in registry with said silencer main flow path; said deflector presenting a surface inclined relative to said silencer main flow path and disposed to direct the flow of air from said main flow path to said opening from said exhaust chamber; and said deflector comprising a porous body for absorbing high frequency sound waves in the air impinging against said inclined surface.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber
  • a silencer mounted on said casing in communication with said exhaust port for damping sound waves in the exhaust air flowing from said motor chamber; said silencer comprising a structure defining an elongated, unobstructed passageway providing a main flow path and outlet for the exhaust air flowing from said port; and said structure defining numerous auxiliary passageways opening from said unobstructed passageway throughout its length to auxiliary outlets, providing auxiliary flow paths from said main flow path for the exhaust air flowing through said silencer.
  • a tool casing having a motor chamber and an exhaust port opening from said motor chamber; means on said casing defining an exhaust chamber communicating with said exhaust port, and an opening from said chamber to ambient atmosphere;
  • a silencer mounted in said exhaust chamber adjacent to said exhaust port for damping sound Waves in the exhaust air flowing from said motor chamber; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and said exhaust port to define a main flow path through said silencer and a main outlet for the exhaust air flowing from said exhaust port; and the spaces between said plates defining auxiliary flow paths from said main flow path and auxiliary outlets for the exhaust air flowing through said silencer.
  • a silencer mounted on said casing adjacent to said exhaust port for damping sound waves in the exhaust air flowing from said motor chamber; said silencer comprising an assembly of thin plates stacked in uniformly spaced relation to each other; each of said plates having an opening, and the openings of said plates registering with each other and with said exhaust port to define a main flow path through said silencer and a main outlet for the exhaust air flowing from said port; and the spaces between said plates defining auxiliary flow paths from said main flow path and auxiliary outlets for the exhaust air flowing through said silencer.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Mechanical Engineering (AREA)
  • Portable Nailing Machines And Staplers (AREA)
  • Stringed Musical Instruments (AREA)
  • Exhaust Silencers (AREA)
  • Auxiliary Devices For Music (AREA)
US338037A 1964-01-16 1964-01-16 Multi-passage silencer for pneumatic tool Expired - Lifetime US3255844A (en)

Priority Applications (4)

Application Number Priority Date Filing Date Title
US338037A US3255844A (en) 1964-01-16 1964-01-16 Multi-passage silencer for pneumatic tool
GB50932/64A GB1075520A (en) 1964-01-16 1964-12-15 Improvements in silencing devices
AT865A AT269011B (de) 1964-01-16 1965-01-04 Schalldämpfer für ein penumatisches Werkzeug
CH15065A CH424676A (fr) 1964-01-16 1965-01-07 Sourdine d'échappement pour outil pneumatique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US338037A US3255844A (en) 1964-01-16 1964-01-16 Multi-passage silencer for pneumatic tool

Publications (1)

Publication Number Publication Date
US3255844A true US3255844A (en) 1966-06-14

Family

ID=23323137

Family Applications (1)

Application Number Title Priority Date Filing Date
US338037A Expired - Lifetime US3255844A (en) 1964-01-16 1964-01-16 Multi-passage silencer for pneumatic tool

Country Status (4)

Country Link
US (1) US3255844A (de)
AT (1) AT269011B (de)
CH (1) CH424676A (de)
GB (1) GB1075520A (de)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3635299A (en) * 1970-04-20 1972-01-18 Gardner Denver Co Muffler for pneumatic tool
DE2539884A1 (de) * 1975-09-08 1977-03-17 Hilti Ag Pulverkraftbetriebenes bolzensetzgeraet mit schalldaempfung
US4093110A (en) * 1977-03-11 1978-06-06 Olin Corporation Noise and fouling reducer for powder-actuated tool
US4109756A (en) * 1976-11-17 1978-08-29 Dresser Industries, Inc. High frequency diffusion muffler for gas jets
DE2827279A1 (de) * 1978-06-21 1980-01-10 Signode Corp Abluftschalldaempfer fuer tragbare pneumatische eintreibgeraete
US4624339A (en) * 1983-11-10 1986-11-25 Charbonnages De France Sound-proofing casing for a pneumatic percussive drill
US4673042A (en) * 1984-05-29 1987-06-16 Sig Schweizerische Industrie-Gesellschaft Pneumatic hammer
US5500494A (en) * 1993-02-19 1996-03-19 Ligman; Gary A. System for modifying operation of pneumatic tool
US5881941A (en) * 1997-06-23 1999-03-16 Basso Industry Corp. Stapler having a silencer
US20090090530A1 (en) * 2007-07-13 2009-04-09 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20090294211A1 (en) * 2008-05-28 2009-12-03 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
US20110126541A1 (en) * 2009-12-02 2011-06-02 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US11867102B2 (en) 2019-08-28 2024-01-09 Snap-On Incorporated Pneumatic tool exhaust muffler

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2820842A1 (de) * 1978-05-12 1979-11-22 Sig Schweiz Industrieges Pneumatisch betaetigtes schlaggeraet
JP2923936B2 (ja) * 1994-11-07 1999-07-26 マックス株式会社 空気圧駆動式釘打機の減音装置

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB356864A (en) * 1930-07-11 1931-09-17 Metropolitan Electric Tramways Improvements in or relating to exhaust silencers
US2073480A (en) * 1934-10-04 1937-03-09 Ingersoll Rand Co Muffling device
GB471431A (en) * 1936-03-03 1937-09-03 Frederick Heather Improvements in and relating to silencers for gaseous currents
US2166218A (en) * 1937-04-06 1939-07-18 Ingersoll Rand Co Muffling device
US2789653A (en) * 1954-05-17 1957-04-23 Fannen John Muffler attachment for air driven tools of the impact type
GB842192A (en) * 1957-11-18 1960-07-20 Aro Equipment Corp Exhaust muffling means
US2966138A (en) * 1958-05-12 1960-12-27 Robert C Quackenbush Muffler construction for portable pneumatic tool

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB356864A (en) * 1930-07-11 1931-09-17 Metropolitan Electric Tramways Improvements in or relating to exhaust silencers
US2073480A (en) * 1934-10-04 1937-03-09 Ingersoll Rand Co Muffling device
GB471431A (en) * 1936-03-03 1937-09-03 Frederick Heather Improvements in and relating to silencers for gaseous currents
US2166218A (en) * 1937-04-06 1939-07-18 Ingersoll Rand Co Muffling device
US2789653A (en) * 1954-05-17 1957-04-23 Fannen John Muffler attachment for air driven tools of the impact type
GB842192A (en) * 1957-11-18 1960-07-20 Aro Equipment Corp Exhaust muffling means
US2966138A (en) * 1958-05-12 1960-12-27 Robert C Quackenbush Muffler construction for portable pneumatic tool

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3635299A (en) * 1970-04-20 1972-01-18 Gardner Denver Co Muffler for pneumatic tool
DE2539884A1 (de) * 1975-09-08 1977-03-17 Hilti Ag Pulverkraftbetriebenes bolzensetzgeraet mit schalldaempfung
US4109756A (en) * 1976-11-17 1978-08-29 Dresser Industries, Inc. High frequency diffusion muffler for gas jets
US4093110A (en) * 1977-03-11 1978-06-06 Olin Corporation Noise and fouling reducer for powder-actuated tool
DE2827279A1 (de) * 1978-06-21 1980-01-10 Signode Corp Abluftschalldaempfer fuer tragbare pneumatische eintreibgeraete
US4227591A (en) * 1978-06-21 1980-10-14 Signode Corporation Muffler for air-powered nailers and the like
US4624339A (en) * 1983-11-10 1986-11-25 Charbonnages De France Sound-proofing casing for a pneumatic percussive drill
US4673042A (en) * 1984-05-29 1987-06-16 Sig Schweizerische Industrie-Gesellschaft Pneumatic hammer
US5500494A (en) * 1993-02-19 1996-03-19 Ligman; Gary A. System for modifying operation of pneumatic tool
US5881941A (en) * 1997-06-23 1999-03-16 Basso Industry Corp. Stapler having a silencer
US20090090530A1 (en) * 2007-07-13 2009-04-09 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US7681690B2 (en) 2007-07-13 2010-03-23 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20100155174A1 (en) * 2007-07-13 2010-06-24 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US7845464B2 (en) 2007-07-13 2010-12-07 Longyear Tm, Inc. Noise abatement device for a pneumatic tool
US20090294211A1 (en) * 2008-05-28 2009-12-03 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
US7735603B2 (en) 2008-05-28 2010-06-15 Longyear Tm, Inc. Noise reducing device for a pneumatic tool
US20110126541A1 (en) * 2009-12-02 2011-06-02 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US8215449B2 (en) 2009-12-02 2012-07-10 Longyear Tm, Inc. Muffler system for noise abatement and ice control
US11867102B2 (en) 2019-08-28 2024-01-09 Snap-On Incorporated Pneumatic tool exhaust muffler

Also Published As

Publication number Publication date
CH424676A (fr) 1966-11-15
GB1075520A (en) 1967-07-12
AT269011B (de) 1969-03-10

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