US3921290A - Chain saw with cyclically restricted and continuously vented acoustic filtering - Google Patents
Chain saw with cyclically restricted and continuously vented acoustic filtering Download PDFInfo
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- US3921290A US3921290A US434654A US43465474A US3921290A US 3921290 A US3921290 A US 3921290A US 434654 A US434654 A US 434654A US 43465474 A US43465474 A US 43465474A US 3921290 A US3921290 A US 3921290A
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- operable
- flow
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- chain saw
- passage
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/18—Construction facilitating manufacture, assembly, or disassembly
- F01N13/1805—Fixing exhaust manifolds, exhaust pipes or pipe sections to each other, to engine or to vehicle body
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B27—WORKING OR PRESERVING WOOD OR SIMILAR MATERIAL; NAILING OR STAPLING MACHINES IN GENERAL
- B27B—SAWS FOR WOOD OR SIMILAR MATERIAL; COMPONENTS OR ACCESSORIES THEREFOR
- B27B17/00—Chain saws; Equipment therefor
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N1/00—Silencing apparatus characterised by method of silencing
- F01N1/08—Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N13/00—Exhaust or silencing apparatus characterised by constructional features ; Exhaust or silencing apparatus, or parts thereof, having pertinent characteristics not provided for in, or of interest apart from, groups F01N1/00 - F01N5/00, F01N9/00, F01N11/00
- F01N13/002—Apparatus adapted for particular uses, e.g. for portable devices driven by machines or engines
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N3/00—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust
- F01N3/06—Exhaust or silencing apparatus having means for purifying, rendering innocuous, or otherwise treating exhaust for extinguishing sparks
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B63/00—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices
- F02B63/02—Adaptations of engines for driving pumps, hand-held tools or electric generators; Portable combinations of engines with engine-driven devices for hand-held tools
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2450/00—Methods or apparatus for fitting, inserting or repairing different elements
- F01N2450/24—Methods or apparatus for fitting, inserting or repairing different elements by bolts, screws, rivets or the like
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
- F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
- F01N2590/00—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines
- F01N2590/06—Exhaust or silencing apparatus adapted to particular use, e.g. for military applications, airplanes, submarines for hand-held tools or portables devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B75/00—Other engines
- F02B75/02—Engines characterised by their cycles, e.g. six-stroke
- F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
- F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
Definitions
- FIG. l2 INLET EXPANSION BAFFLE CYCLIC RESTRICTION AND VENTING DEFLECTION DISCHARGE
- a further object of the invention is to accomplish the hertofore stated objectives with respect to noise suppression and maintenance of effective engine power side in a technique characterized by the following method steps.
- This method aspect involves a method for reducing the operating noise of a chain saw which includes chain saw cutting means including guide bar means, and cutter chain means supported on the guide bar means for traversal through a cutting path.
- the chain saw further includes chain saw power means including chain saw engine means having a working chamber means, and chain saw power transmitting means operable to transmit driving force to said cutter chain means and cause said cutter chain means to traverse said cutting path.
- inventive aspects of this method reside in cooperative steps including the provision of exhaust passage means communicating with the working chamber means of the chain saw engine means and transmitting a flow of cyclically pulsing exhaust gas from the working chamber means through the exhaust passage means.
- This flow of exhaust gasis cyclically restricted.
- a flow of at least a portion of this flow of exhaust gas through the exhaust passage means is continuously vented to the atmosphere.
- the cyclic restricting of the flow of exhaust gas is caused to occur through the unimpeded, cycling action of a free floating, flow restricting element.
- Another independently significant method aspect of the invention entails the following combination of method steps.
- This method relates to the reducing of the operating noise of a chain saw, which chain saw includes chain saw cutting means having guide bar means, and cutter chain means supported on the guide bar means for traversal through a cutting path.
- the chain saw further includes chain saw power means including chain saw engine means having a working chamber means, and chain saw power transmitting means operable to transmit driving force to the cutter chain means and cause the cutter chain means to traverse the cutting path.
- Inventive aspects of this method reside in steps initiated by the provision of exhaust passage means communicating with the working chamber means of the chain saw engine means and transmitting a flow of cyclically pulsing exhaust gas from the working chamber means through this exhaust passage means. This flow of exhaust gas is passed into surge chamber means, with the flow being operable to expand therewithin.
- Acoustic filter means including generally tubular means including lateral wall means defining interior passage means communicating with the atmosphere and extending within the surge chamber means.
- This acoustic filter means further includes transverse passage means intersecting the lateral wall means of the generally tubular means and providing restricted, acoustic filtering, fluid communication between the surge chamber means and the interior passage means of the generally tubular means.
- the flow of exhaust gas is acoustically filtered by passing the flow from the surge chamber means through the acoustic filter means. At least a portion of the flow of exhaust gas passing through said acoustic filter means is cyclically restricted and a portion of the flow of exhaust gas tothe atmosphere is continuously vented.
- the flow restricting means is telescopingly associated with the tubular means and is supported by the noise reducing apparatus for substantially unimpeded reciprocating movement relative to the tubular means.
- the flow restricting means includes wall means telescopingly associated with the tubular means and is operable to cooperate with such lateral wall means and interior passage means of said tubular means to define generally annular passage means within the interior passage means.
- the continuously operable venting means comprises generally central venting passage means extending generally centrally and longitudinally of each of the flow restricting means and the annular passage means, with the venting passage means being defined by and carried by the flow restricting means.
- the generally annular passage means provides fluid communication between the generally central. venting passage means and the surge chamber means.
- the generally annular passage means is operable to provide fluid communication, independent of the generally central venting passage means, between the atmosphere and the surge chamber means.
- the flow restricting means includes generally annular, flow restricting wall means extending transversely of the generally annular passage means, which annular wall means is cyclically operable in response to the flow of exhaust gas to cyclically restrict a portion of the annular passage means communicating with the atmosphere.
- This generally annular wall means is opera- DRAWINGS Preferred embodiments of the present invention are illustrated in the appended drawings in which:
- FIG. 1 provides a fragmentary, perspective view of a representative chain saw in which a preferred noise suppressing apparatus of the present invention is incorporated;
- FIG. 2 provides an enlarged, exploded, perspective view of disassembled components of a preferred noise suppressing apparatus incorporated in the FIG. 1 chain saw; 7
- FIG. 3 provides a still further enlarged sectional view of the FIG. 2 noise suppressing apparatus as viewed generally along section line 3-3 of FIG. 2;
- FIG. 4 provides an enlarged sectional view of the FIG. 2 noise suppressing apparatus as viewed along section line 4-4 of FIG. 2;
- FIG. 5 provides a still further enlarged, transverse, sectional view'of the FIG. 2 noise suppressing apparatus as viewed generally along section line 55;
- FIG. 6 provides an elevational sectional view of the cyclically operable flow restricting mechanism illustrated in perspective view in FIG. 2;
- FIG. 7 provides a transverse sectional viewof the FIGS. 2 and 6 exhaust flow restricting means as viewed along section line 7-7 of FIG. 6;
- FIG. 8 provides a sectioned, elevational view of a first alternative form of a flow restricting mechanism which may be employed in lieu of the FIG. 6 device;
- FIG. 9 provides a transverse sectional view of the alternative flow restricting embodiment shown in FIG. 8, as viewed along section line 9-9 of FIG. 8;
- FIG. 10 illustrates in a sectional, elevational format, a still further alternative embodiment of a cyclically operable exhaust flow restricting mechanism which also may be employed in lieu of the mechanism shown in FIGS. 2 and 6; I
- FIG. 1 illustrates a representative 'chain saw 1, including a muffler ornoisesuppressing apparatus 2 fabricated in accordance with any of several embodiments of the present invention.
- Chain saw 1 includes a guide bar 101.
- a cutter chain 102 is slidably supported on the periphery of the guide bar 101 for movement through a cutting plane defining a cutting path.
- This cutting plane may be considered to comprise a longitudinally extending, upright median plane coextensive with the generally ovate cutter chain configuration.
- Chain saw '1 comprises an engine-assembly 103 including a piston and cylinder means 104. As shown in FIG. 1, a cylinder or working chamber component of the piston and cylinder assembly 104 may be oriented so that the axis of reciprocation of the piston longitudinally of the guide bar 101 and the aforesaid cutting plane.
- a crankshaft means 106 including the external housing 107 shown in FIG. 1, is operated in a manner now well understood to translate reciprocating movement of the piston of the engine assembly 103 into rotary movement of a sprocket wheel which is disposed in driving engagement with a cutter chain 102.
- crankshaft is mounted for rotation about an axis of crankshaft rotation 108 which extends generally perpendicular to the aforesaid cutting plane, Le, a planar extension of the longitudinal upright median plane of the guide bar 101.
- the chain saw 1 will generate vibrations principally aligned with a plane extending generally parallel to or longitudinally of the aforesaid cutting plane.
- the axis of crankshaft rotation 108 may be deemed to pass generally perpendicular to this principal vibration plane.
- FIGS. 2 through 7 a first embodiment illustrated in FIGS. 2 through 7
- FIGS. 8 and 9 a second embodiment illustrated in FIGS. 8 and 9
- FIGS. 10 and 11 a third embodiment illustrated in FIGS. 10 and 11.
- the first embodiment of muffler 2 shown in FIGS. 2 through 7 comprises a conduit means 3 which is operable to transmit exhaust fluid from the cylinder means 105.
- conduit means 3 may be disposed in direct metal-to-metal engagement with an exterior mounting boss 109 of the cylinder 105 and communicate directly with a cylinder exhaust port 110.
- This metal-to-metal juncture 111 may be supplemented by a gasket 111a as shown in FIGS. 3 and 4, but the metallic extremity of the conduit 3 is disposed largely in direct, contiguous, abutting engagement with the metallic cylinder boss 109.
- Conduit means 3 may have a generally rectangular cross section extending in a direction perpendicular of longitudinal axis 301 of conduit means 3, as depicted generally in FIG. 4.
- This longitudinal axis 301 may extend generally parallel to the axis of crankshaft rotation 108, when the muffler 2 is installed as shown in FIG. 1.
- conduit means 3 may comprise a generally tubular metallic wall portion 302, having a generally rectangular (but round cornered, i.e., ended) cross section extending transversely of axis 301.
- Conduit 3 may be somewhat composite in nature, comprising a sheet metal portion 303 connected (as by brazing) with an apertured, plate-like terminus 304.
- the terminus 304 being plate-like and flat in configuration, will ensure contiguous, uniform and generally flush engagement between the end of the conduit 3 and the boss 109 at the juncture zone 111.
- conduit means 3 may not be elongate as shown in FIGS. 2 through 6, but instead may merely comprise a port or passage means in the base of a surge or expansion chamber 4. Such an arrangement could result by fabricating the cylinder .mounting bosses 109 and 112, shown in FIG. 4, so that they were generally coplanar and engageable with spaced portions of a flat boss of a muffler unit.
- muffler 2 additionally includes a surge chamber 4.
- This surge chamber is operable to receive exhaust fluid from the conduit means 3 at a juncture or exhaust passage zone 401 between these components.
- the surge chamber 4 may be fabricated from metallic halves 402 and 403 which may be telecoped together and brazed or crimped at juncture zone 404.
- Body or shell portion 403 of the surge chamber means may be provided with a mounting pad zone 405 which may be disposed in direct, metal-to-metal engagement with the aforesaid mounting boss 112 which is formed on the exterior of cylinder 105. In this manner, the surge chamber means 4 is supported directly on the exterior of the cylinder means 105.
- conduit means 3 extends between the interior of the surge chamber means 4 to the juncture zone 111.
- the surge chamber 4 may have an overall, generally rectangular configuration (albeit somewhat rounded) encircling the surge chamber interior 406 (within which exhaust gas expands) and includes a generally rectangular cross section extending generally parallel with the aforesaid principal vibration plane.
- Muffler 2 further includes acoustic filter means 5 depicted generally in FIGS. 3, 4 and 5.
- Acoustic filter means 5 comprises a first, generally perforate, sheet metal cylinder means 501 having a longitudinal axis extending generally parallel to the axis of crankshaft rotation 108.
- a longitudinal central axis 502 of the first cylinder means 501 is transversely displaced from the longitudinal central axis 301 of the conduit means 3.
- the perforate cylinder means 501 and the conduit means 3 may be considered as being mutually transversely offset along a plane extending parallel to the aforesaid principal vibration plane.
- Acoustic filter means 5 may be considered to include a second cylinder means 503 which is contained within the first cylinder means 501.
- This second cylinder means 503 is somewhat smaller in diameter than the internal size of cylinder means 501 so as to be generally radially spaced inwardly thereof.
- a cap-like, end wall or barrier 504 serves to close first end portion 505 of cylinder means 501. As shown in FIG. 5, this metallic barrier cap 504 may be partially telescoped within a first inner end 505 of cylinder 501 and be brazed into a fixed position relative to, and connected with, cylinder 501.
- cap 504 comprises a barrier means which operates to close the first end portion 505 of the cylinder means 501.
- this first cylinder end portion 505 may be viewed as being generally mutually contiguous with the rim of cap 504 and housed within the interior of 406 of the surge chamber 7 means 4.
- the second or outer end 508 of cylinder 501 may be deflected generally radially outwardly so as to provide a mounting ledge 508a.
- This ledge or rim may be abuttingly engageable with an annular mounting shoulder 407 of the surge chamber means.
- an outwardly deflected and generally radially extending shoulder 509 of the cylinder means 503 may provide a shoulder or annular rim disposed axially outwardly of, but engageable with, the rounded inner corner of shoulder 508a of the first cylinder means 501.
- Cylinder 503 and its annular rim wall 509 provide an open-ended, generally tubular means which is telescopingly mounted within tubular means 501, for cyclic flow restricting purposes, as will be hereinafter described.
- This open-ended cylinder means provides a venting passage 511a disposed within interior passage 511 of tubular means 503 and communicating with interior 406 of surge chamber 4 via open end 511b.
- the rim defining, upper end 509 of the inner cylinder 503 comprises annular wall means extending generally transversely of and between the second or outer end portions of the first and second cylinder means 501 and 503.
- the upper end 509 of the cylinder 503, like the end 508 of cylinder 501, generally encircles the outlet means 510 which is operable to continuously transmit exhaust fluid to the exterior of the surge chamber means.
- the outer cylinder 501 includes a plurality of generally radially extending, longitudinally elongate, and circumferentially spaced first perforations 512. As shown in FIGS. 5 andS, two such longitudinally displaced rows of perforations 512 may be provided. One row 512a discharges into annular passage 514 between cylinders 501 and 503 while another row 512b discharges directly into interior 5116 at the innermost end of the acoustic filter.
- each opening 512 may be on the order of 0.125 inches, with the length of each such opening 512 being on the order of 0.50 inches.
- the radial gap between the cylinders 501 and 503 provides the aforesaid, constricted annular flow path 514 extending longitudinally of and interposed generally radially between the first and second cylinder means'50l and 503.
- This flow path, along with the perforation512, is believed to perform a significant sound attenuating function.
- the constricted annular flow path 514 extends generally along the axis 502.
- the engine 103 are operable to generate vibrations generally aligned with this principal vibration plane and acting on the first and second cylinder means 501-503. These vibrations are generated so as to be directed generally transversely of the constricted annular flow path 514 and in general alignment with the cutting plane.
- this fluid may flow generally radially between interior space 406 and space 511, while some 8 fluid flow will be resisted by the solid wall portions of side wall means 503a of cylinder 503 so as to flow generally longitudinally of axis 502 along the path 514, both toward area 511(- and a flow restricting passage means 51 1d at the outer end of the acoustic filter which wiill be hereinafter described in greater detail.
- Muffler 2 additionally may include a plurality of generally tubular components 6 which function as housings for fastening members. These components 6 may provide a form of internal baffle action in the surge chamber 4. These tubular components 6 also serve the function of reducing the unsupported or unbraced wall or panel area of the muffler chamber 4 and may act to reduce airborne noise eminating from vibrating wall or panel areas.
- muffler 2 may include three generally tubular housing or baffle members 601, 602 and 603.
- Each such baffle member extends generally parallel to the axis of crankshaft rotation and thus parallel to the axes 502 and 301.
- tubular housing or baffle members 601-603 may be brazed to surge chamber shell portion 402 at a juncture 604 and extend through the surge chamber interior 406.
- Two of the baffles 601 and 602 may pass longitudinally through upper and lower ends of the conduit means 3, as generally shown in FIG. 3.
- baffle or housing members I 601-603 i.e., the ends disposed adjacent the cylinder 105, may be secured by a brazing arrangement involvcalled that axis 502 extends generally perpendicular to.
- a representative tubular member 602 telescopingly receives a generally tubular and radially flanged fitting 605. Another end of fitting 605 passes through an apertured portion of end wall lip 305 of conduit means 3 so as to be telescopingly received within an aperture 306 of mounting plate 304.
- the brazing of a fitting 605 to an end of tubular member 602 and to the base plate 304 will serve to effectively interconnect the components 602, 303 and 304.
- tubular member 603. This same general mode of assembly may be employed in connection with tubular member 603.
- This member may be secured by brazing to mounting pad portion 405 of shell 403.
- opposite ends of a tubular flanged fitment 606 may be partially telescopingly received within an end of tubular member 603 and an opening wall 405, respectively, and be brazed to these components so as to effect their interconnection.
- conduit means 3 the first and second cylinder means 501 and 503, the constricted annular flow path 514, and the tubular baffle means 601603 are all arranged so that their longitudinal axes are generally mutually parallel. All of these components are subject to vibrations generated in general alignment with the principal vibration plane heretofore described.
- baffle means 601-603 The precise baffle phenomenon which may be attributable to the baffle means 601-603 is not fully understood. Nevertheless, it is believed that the nonsymmetric disposition of these baffle means, spaced generally radially outwardly of the cylinder means 501, contribexiting from outlet means 510 in a direction extending generally transversely of the axis of crankshaft rotation,
- deflector means 7 may include arcuate wall 1 means 701 having a generally quarter-sphereconfiguration.
- This quarter-sphere configuration is oriented such that its center of curvature 702 is generally coincident with the centrallongitudinal axis 502 common to the first and second cylinder means 501 and 503, respectively.
- quarter-sphere wall 701 may be supported on a mounting rim 703 which has apertured clampor ear means 704 and 705.
- the rim 703 may be positioned so as to dispose the apertured ear portions 704 and 705 in general alignment with threaded fastener receiving openings 710 and 711 formed on surge chamber means 4.
- the insertion of threaded fasteners 712 and.713 through these ear portions and fastener receiving openings into threaded cooperation with threaded nut means 714 and .715 (brazed to the. interior of surge chamber 4) will complete the installation of the deflector assembly.
- the position f the threaded fasteners 712 and 713 and their associated threaded nut means 714 and 715 may notably, as shown generally-in FIGS. 2 and '5, as to cause the deflector wall 701 to be disposed with its opening 716 directed directly downwardly, i.e., away from the upper part of the chain saw where an operators hands would be disposed.
- the deflector may be inverted and the wall means 701 configured so as to provide a deflected flow of exhaust fluid onto an operators hands for operator hand warming purposes.
- the deflector 701 may also be oriented so as to deflect warm exhaust fluid into portions of the chain saw for the purpose of warming components such as' the carburetor, air filter, etc. located generally in upper area 113 of the chain saw-,shown in FIG. 1.
- the muffler 2 as heretofore described, will function to effectively attenuate noise generated by the engine means 103 through the synergistically cooperating interaction of the exhaust passage means 3, surge chambermeans 4, acoustic filter means 5, and cyclically operable flow restricting means 503 and 509, possibly fa cilitated by baffle action provided by baffle means 6.
- Exhaust fluid will flow from the cylinder discharge port 1 10 into the surge chamber interior 406 by way of exhaust passage 3 and expand therein. Baffling of this flow will result if the conduit means 3 and the cylinder means 501 and 503 are displaced. Further baffling of this flow may result from a nonsymmetric orientation and presence of the baffle means 601-603.
- a thus baffled flow of fluid in the surge chamber 4 will pass through the perforation means 512 for acoustic filtering, i.e., noise attenuation, and thereafter be transmitted to the exhaust outlet 510.
- a unique modification involving an advantageous blunting of pressure pulses, or dissipating or spreading of noise energy so as to reduce peak noise intensity may be achieved by cyclically restricting the outflow of exhaust gas from the acoustic filter 5 while providing for continuous unimpeded venting of a portion of exhaust flow from the acoustic filter.
- Distinctive characteristics of this new concept reside in part in the utilization of a freely movable or unbiased, cyclically operable, flow restricting mechanism.
- annular passage 514 including the outlet, flowcontrolling, annular passage portion 511d,
- continuous venting passage means 510-51 la-51 1c which communicate directly with openings 512b of the acoustic filter 5.
- the sleeve flange 509 extends transversely across the annular passage means 511d so as to effectively restrict and substantially close off this portion of the exhaust gas flow path.
- the sleeve 503 is mounted for free telescoping movement and is not biased toward any particular extremity of its range of telescoping movement. Moreover, the sleeve 503 is free, to some extent and while at rest, to cant" within the outer sleeve 501.
- these desirable objectives are achieved without generating annoying rattling noise as a result of the oscillating or telescoping action of the sleeve 503. It may well be that the significant absence of excessive rattling noise is a result of a form of air cushioning resulting from the cyclic movements of the sleeve 503 being in a somewhat out-of-phase relation with the pressure pulses of the exhaust gas, i.e., with the flange 509 tending to seat on the rim 508 during portions of positive pressure pulses.
- FIGS. 2 through 7 In summarizing the mode of operation of muffler 2, reference will be made to FIGS. 2 through 7 as well as to FIG. 12.
- FIG. 12 schematically illustrates, in a functional sense, various noise reducing or attenuating functions which are performed by the totality of operations of the preferred embodiment.
- FIG. 12 schematically illustrates, in a functional sense, various noise reducing or attenuating functions which are performed by the totality of operations of the preferred embodiment.
- the overall improvement in the noise reducing apparatus 2 resides in an apparatus as follows.
- An exhaust passage means 3 communicates with the working chamber means 105 of the chain saw engine means 103 and is operable to transmit a flow of cyclically pulsing exhaust gas therefrom.
- the surge chamber means 4 is operable to receive the flow of exhaust gas from the exhaust passage means 3 and transmit it to acoustic filter means 5.
- the acoustic filter means 5 includes generally tubular means 501 including lateral wall means defining interior passage means 511 communicating with the atmosphere and extending within the surge chamber means 4. Acoustic filter means 5 further includes transverse passage means 512 intersecting the lateral wall means of the generally tubular means 501 and providing restricted, acoustic filtering, fluid communication between'the surge chamber means 4 and the interior passage means 511 of the generally tubular means 501.
- a flow restricting means 8 is mounted in'the generally tubular means 501 and is operable to cyclically restrict at least a portion'of the flow of exhaust gas.
- a continuously operable venting means 511a-510 is operably associated with the generally tubular means 501 and is operable to maintain a continuously open flow path 511a-510 between the surge chamber'means 4 and the atmosphere, through which path at least a portion of the flow of exhaust gas from the chain saw engine means 103 may continuously pass.
- the noise reducing apparatus 2 may include a plurality of asymmetrically arranged tubular members 601, 602, 603 defining baffle means 6 contained within the surge chamber means 4 and operable to baffle the flow of exhaust gas within the surge chamber means 4 between the exhaust passage means 3 and the acoustic filter means 5.
- the flow restricting means 8 is free floating and telescopingly associated with the tubular means 501 and is supported by the noise reducing apparatus 2 for substantially unimpeded reciprocating movement relative to the tubular means 501.
- This flow restricting means 8 includes wall means(i.e., 503a or 503a or 503a) telescopingly received with the tubular means 501 and operable to cooperate with the lateral wall means of the tubular me ans interior passage means 5 ll of the tubular means and define generally annular passage means 514 within the interior passage means 51 1.
- the annular passage means 514 is operable to deflect a flow of exhaust gas passing transversely of the lateral wall means through the transverse passage means 512 and cause this deflected flow of exhaust gas to flow generally longitudinally of the interior passage means 511
- the continuously operable venting means 511a-510 comprises a generally central, venting passage means 511a extending generally centrally and longitudinally of each of the flow restricting means 8 and the annular passage means 514, with this venting passage means being defined by and carried by the flow restricting means 8.
- the generally annular passage means 514 provides fluid communication between the generally central,
- the generally annular passage means 514 is also operable to provide fluid communication, independent of the generally central venting passage means 511a, between the atmosphere and said surge chamber means interior 406 via outlet 511d.
- the flow restricting means 8 includes generally annular, flow restricting wall means 509 extending transversely of the generally annular passage means 514.
- the wall means 509 is cyclically operable in response to the flow of exhaust gas to cyclically restrict a portion 511d of the annular passage means 514 communicating with the atmosphere.
- the generally annular wall means 509 is operable to move away from the annular passage means 514 and tend to reduce restriction of the generally annular passage means area 511d and is operable to move toward the annular passage means portion 511d and increase restriction of the generally annular passage means 514.
- the noise reducing apparatus 2 may further include flow deflecting means 7 providing exhaust gas deflecting, fluid communication between the flow of exhaust gas issuing from the interior passage means 51 1 and the atmosphere.
- This flow deflecting means 7 includes restitution means 701a operable 1) to be impacted by the flow restricting means 8, when the generally annular wall means 509 is moving away from the annular passage means 514 and tending to reduce the restriction of the generally annular passage means 514 and 2) to induce a rebounding of the flow restricting means 8 tending to move the generally annular wall means 509 toward the annular passage meand 514 and induce an increase in restricting of the generally annular passage means 514.
- the transverse passage means 512 of the acoustic filter means may include a first plurality 512a of elongate openings extending longitudinally of the generally annular passage means 514, spaced circumferentially about the generally tubular means 501, and operable to discharge exhaust gas directly into the generally annular passage means 514.
- the transverse passage means 512 may further include a second plurality 51219 of elongate openings, comprising, in effect, a portion of the continuously operable venting means, and operable to discharge exhaust gas into the interior passage means 511C without passage through the generally annular passage means 514.
- Exhaust gas is received by inlet passage means 3, as depicted in function block A of FIG. 12;
- Exhaust gas is expanded within surge chamber 4, as depicted in block B of FIG. 12;
- Exhaust gas is baffled by baffle means 6 and/or perforation means 512, as depicted by block C in FIG. 12;
- Exhaust gas is acoustically filtered so as to attenuate noise levels by acoustic filter means 5, as depicted by block B of FIG. 12;
- Exhaust gas is cyclically restricted and is continuously vented (as implemented by flow restricting and venting means 8), as generally depicted in block E of FIG. 12;
- Exhaust gas is deflected by deflecting means 7 as it issues from the acoustic filter means 5 under the control of flow restricting and venting means, 8 as generally depicted by block F of FIG. 12;
- Noise modulated exhaust gas is discharged to the atmosphere as generally depicted by block G of FIG. 12.
- interior passage means 3 and surge chamber 4 may be substantially varied, as may be the dimensions, arrangement, shapes and numbers of the baffle means 6 (i.e., 601, 602, 603) and/or passages 512.
- the deflector 7 may be significantly altered in form, size and shape as may be the acoustic filter 5.
- phase restricting and venting means 8 a variety of structural modifications are foreseeable which would serve to vary the structural nature of the cylinder or floating thimble or valve" 503, the radial width of the gap 514, the size of the vent opening 510, and the weight and length of the mechanism 8.
- mechanism 8 may comprise a modified cylinder 503 having a perforate sidewall 503a and annular rim 509 which provides an orifice-like, central opening 510 and a somewhat narrower width for passage 514.
- Wall 5030 may be provided with a series of circumstantially spaced longitudinally elongate ports or openings 503b.
- a cylinder-like component 503 is provided with side wall means 503a" defined by a plurality of circumferentially spaced, leg-like components 503C.
- the legs 503c are connected with a platelike rim defining component 509" which affords a central, orifice-like vent outlet 510".
- FIGS. 6 and 7 species is believed to be particularly effective, structurally simple, and operationally reliable.
- the length of the cylinder side wall i.e., the side wall 503a of the FIGS. 6 and 7 species, for example
- the length of the cylinder side wall would be such as shown in FIG.
- the invention might also be able to be effectively practiced with the length of the sleeve side wall (such as, for example, wall 503a) being extended so as to overlap in whole or in part the perforation means 51212 or extend generally deeper or further into'the cylinder 501.
- the wall structure of the acoustic filter 5 may vary, particularly in accordance with the prior teaching of our parent application Ser. No. 220,632.
- the mechanism 8 of the present invention may be telescopingly mounted within a single cylinder 501 as shown in the aforesaid parent application or may be telescopingly mounted within a doublewalled acoustic filtering, cylinder arrangement depicted in FIG. 8 of the aforesaid parent application (i.e., telescopingly mounting within a perforated metal inner wall component 503 illustrated in FIG. 8 of the aforesaid parent application). This arrangement would produce a pair of coaxially arranged acoustic filtering,
- annular passages one existing between the cylinder walls 501 and 503 of the aforesaid parent application and the other existing between the cylinder 503 of the aforesaid parent application and the side wall 503 of the mechanism 8 of the present invention (i.e., for example, 503a).
- a uniform pattern of relatively small perforations could be employed, in lieu of the elongate slot featured in the present disclosure, along with other transverse opening arrangements.
- Such a uniform pattern arrangement is described, for example, in the aforesaid parent application in relation to inner sleeve or cylinder 503 of that application.
- a particular advantage of the invention resides in the manner in which effective noise reduction and attenuation is achieved without sacrificing excessive engine power, particularly at low and median speeds of engine operation.
- a noise level reduction on the order of five or so decibels has been attained.
- a minimization or suppression of rattling of the control mechanism 8 is attained which is believed to be particularly desirable. This may be attributed, in part, to air cushioning which could result from the mechanism 8 cycling in a somewhat out-of-phase relation with positive pressure peaks of the exhaust gas.
- a chain saw including an apparatus for reducing the noise generated by chain saw operation
- said chain saw includes chain saw cutting means including guide bar means, and cutter chain means supported on said guide bar means for traversal through a cutting path; and chain saw power means including chain saw engine means having a working chamber means, and chain saw power transmitting means operable to transmit driving force to said cutter chain means and cause said cutter chain means to traverse said cutting path;
- said noise reducing apparatus comprising: exhaust passage means communicating with said working chamber means of said chain saw engine means and operable to transmit a flow of cyclically pulsing exhaust gas therefrom; generally tubular, outlet passage means operable to receive said flow of exhaust gas and transmit said flow to the atmosphere; exhaust flow responsive, cyclically operable flow restricting means telescopingly mounted in said outlet passage means and operable in response to pressure pulsations in said flow of exhaust gas to cyclically restrict a portion of said flow of exhaust gas transmitted through said outlet passage means; continuously operable venting means operable to permit a continuous flow of a portion of said flow of exhaust gas through said outlet passage means to the atmosphere concurrent with said cyclic
- chain saw power means including chain saw engine means having a working chamber 18 means being defined by and carried by said flow restricting means; said generally annular passage means providing fluid communication between said generally cenmeans, and tral, venting passage means and said surge chamchain saw power transmitting means operable to bet means;
- chain saw including an apparatus for reducing the noise generated by an operating chain saw, wherein said chain saw includes chain saw cutting means including guide bar means, cutter chain means supported on said guide bar means for movement through a cutting plane; chain saw engine means including said continuously operable venting means comprising generally central venting passage means extending generally centrally and longitudinally of each of said flow restricting means and said annular passage means, with said venting passage piston said cylinder means,
- crankshaft means driven by said piston means of said piston and cylinder means, and operable to transmit driving force to said cutter chain means;
- said noise reducing apparatus comprising:
- conduit means operable to transmit cyclically pulsing exhaust fluid from said cylinder means of said piston and cylinder means; I surge chamber means,
- surge chamber means being operable to receive exhaust fluid from said conduit means; acoustic filter means including generally perforate, outlet passage defining means, said conduit means and said outlet passage defining means being mutually offset,
- outlet means provided by a second end of said outlet passage defining means
- said outlet means being operable to transmit exhaust fluid to the exterior of said surge chamber means
- said outlet passage defining means including a plurality of openings providing communication between said outlet means and the interior of said surge chamber means;
- tubular baffle means being located within the interior of said surge chamber means
- tubular baffle means being mutually displaced and disposed nonsymmetrically in relation to said outlet passage defining means;
- flow restricting means operable to cyclically restrict a flow of said exhaust fluid passing through said acoustic filter means
- venting means operable to permit a continuous flow of at least a portion of a flow of said exhaust fluid through said acoustic filter means to the atmosphere; and support means mounting said flow restricting means for substantially unimpeded cyclic movement.
- chain saw including an apparatus for reducing the noise generated by an operating chain saw, wherein said chain saw includes chain sawcutting means includin guide bar means,
- cutter chain means supported on said guide bar means for movement through a cutting plane with said cutting plane being aligned in generally parallel relation with a principal vibration plane of a chain saw;
- chain saw engine means including piston and cylinder means
- crankshaft means driven by said piston means of said piston and cylinder means, and operable to transmit driving force to said cutter chain means;
- said noise reducing apparatus comprising:
- conduit means operable to transmit cyclically pulsing exhaust fluid from said cylinder means of said piston and cylinder means
- conduit means having a longitudinal axis extending generally parallel to said axis of crankshaft rotation;
- said surge chamber means being operable to receive exhaust fluid from said conduit means
- said surge chamber means having a generally rectangular cross section extending generally parallel with said principal vibration-planej acoustic filter means including a generally perforate cylinder means having a longitudinal axis extending generally parallel to said axis of crankshaft rotation,
- said outletmeans being operable to transmit exhaust fluid to the exterior of said surge chamber means
- said cylinder means including a plurality of generally radially opening and circumferentially spaced perforation means,-
- said cutter chain means and chain saw engine means being operable to generate vibrations generally aligned with said principal vibration plane and acting on said cylinder means to generate vibrations therein directed generally transversely thereof and in general alignment with said principal vibration plane;
- venting means operable to permit a continuous flow of at least a portion of a flow of said exhaust fluid through said acoustic filter means to the atmosphere;
- a chain saw including an apparatus for reducing the noise generated by an operatingchain saw
- said chain saw includes I chain saw cutting means including guide bar means, i cutter chain means supported on said guide bar means for movement through a cutting plane, with said cutting plane being aligned in generally parallel relation with a principal vibration plane of a chain saw;
- I chain saw engine means including piston and cylinder means, crankshaft means driven by said piston means 'of said piston and cylinder means, andgoperable to transmit driving force to said cutter chain means, said'crankshaft means being mounted for rotation about an axis of crankshaft'rotation extending generally perpendicular to said principal vibration plane;
- said noise reducing apparatus comprising:
- conduit means operable to transmit cyclically pulsing exhaust fluid from said cylinder means of said piston and cylinder means, said conduit means having a generally rectangularlyelongate cross section, and
- conduit means having a longitudinal axis extending generally parallel to said axis of crankshaft rotation; surge chamber means,-
- said surge chamber means being operable to receive exhaust fluid from said conduit means
- said surge chamber means being supported on the exterior of said cylinder means
- conduit means extending from said surge chamber means and being directly connected with the exterior of said cylinder means and disposed in direct, metal-to-metal engagement therewith,
- said surge chamber means having a generally rectangular configuration including a generally rectangular cross section extending generally parallel with said principal vibration plane;
- acoustic filter means including generally perforate cylinder means having a longitudinal axis extending generally parallel to said axis of crankshaft rotation,
- said outlet means being operable to transmit exhaust fluid to the exterior of said surge chamber means
- said cylinder means including a plurality of generally radially opening and circumferentially spaced perforation means, and said cutter chain means and chain saw engine means being operable to generate vibrations generally aligned with said principal vibration plane and acting on said cylinder means to generate vibrations therein directed generally transversely thereof and in general alignment with said principal vibration plane; a plurality of tubular baffle means,
- tubular baffle means being located within the interior of said surge chamber means, each said tubular baffle means extending generally parallel to said axis of crankshaft rotation, and said tubular baffle means being mutually displaced and spaced generally radially outwardly of said cylinder means; said conduit means, said cylinder means, and said tubular baffle means being generally mutually parallel and subject to said vibrations generated in general alignment with said principal vibration plane; flow restricting means operable to cyclically restrict a flow of said exhaust fluid passing through said acoustic filter means; continuously operable venting means operable to permit a continuous flow of at least a portion of a flow of said exhaust fluid through said acoustic filter means to the atmosphere; and support means mounting said flow restricting means for substantially unimpeded cyclic movement.
- exhaust passage means operable to communicate with a working chamber means of cyclic, internal combustion engine means and operable to transmit a flow of cyclically pulsing exhaust gas therefrom;
- outlet passage means operable to receive said flow of exhaust gas and transmit said flow to the atmosphere; exhaust flow responsive, cyclically operable, flow restricting means telescopingly mounted in said outlet passage means and operable in response to pressure pulsations in said flow of exhaust gas to cyclically restrict a portion of said flow of exhaust gas transmitted through said outlet passage means;
- venting means operable to permit a continuous flow of a portion of said flow of exhaust gas through said outlet passage means to the atmosphere concurrent with said cyclic restriction of a portion of said exhaust gas flow through said outlet passage means;
- a chain saw including an apparatus for reducing the noise generated by chain saw operation. and wherein said chain saw includes chain saw cutting means including guide bar means, and cutter chain means supported on said guide bar means for traversal through a cutting path; and chain saw power means including chain saw engine means having a working chamber means, and chain saw power transmitting means operable to transmit driving force to said cutter chain means and cause said cutter chain means to traverse said cutting path; the improvement in said noise reducing apparatus comprising:
- exhaust passage means communicating with said working chamber means of said chain saw engine means and operable to transmit a flow of cyclically pulsing exhaust gas therefrom;
- surge chamber means operable to receive said flow of exhaust gas from said exhaust passage means
- acoustic filter means including generally tubular means including lateral wall means defining interior passage means communicating with the atmosphere and extending within said surge chamber means, and
- transverse passage means intersecting said lateral wall means of said generally tubular means and providing restricted, acoustic filtering, fluid communication between said surge chamber means and the interior passage means of said generally tubular means;
- flow restricting means mounted in said generally tubular means and operable to cyclically restrict at least a portion of said flow of exhaust gas
- continuously operable venting means operably associated with said generally tubular means and operable to maintain a continuously open flow path between said surge chamber means and said atmosphere through which at least a portion of said flow of exhaust gas from said chain saw engine means may continuously pass;
- said flow restricting means being telescopingly associated with said tubular means and supported by said noise reducing apparatus for substantially unimpeded reciprocating movement relative to said tubular means;
- said flow restricting means including wall means telescopingly received with said tubular means and op- 23 erable to cooperate with said lateral wall means and interior passage means of said tubular means and define generally annular passage means within said interior passage means;
- said continuously operable venting means comprising generally central venting passage means extending generally centrally and longitudinally of each of said flow restricting means and said annular means, with said venting passage means being defined by and carried by said flow restricting means;
- said generally annular passage means providing fluid communication between said generally central, venting passage means and said surge chamber means;
- said generally annular passage means being operable to provide fluid communication, independent of said generally central venting passage means, be-
- said flow restricting means including generally annular, flow restricting wall means extending transversely of said generally annular passage means and cyclically operable, in response to said flow of exhaust gas, to cyclically restrict a portion of said annular passage means communicating with said atmosphere.
- said generally annular wall means being operable to move away from said annular 1 passage means and tend to reduce restriction of said generally annular passage means and operable to move toward said annular passage means and increase restriction of said generally annular passage means.
- a chain saw including an apparatus for reducing the noise generated by chain saw operation. and wherein said chain saw includes chain saw cutting means including guide bar means, and
- cutter chain means supported on said guide bar means for traversal through a cutting path
- chain saw power means including chain saw engine means having a working chamber means
- chain saw power transmitting means operable to transmit driving force to said cutter chain means and cause said cutter chain means to traverse said cutting path
- acoustic filter means including generally tubular means including lateral wall means defining interior passage means communicating with the atmosphere and extending within said surge chamber means, and transverse passage means intersecting said lateral wall means of said generally tubular means and providing restricted, acoustic filtering, fluid communication between said surge chamber means and the interior passage means of said generally tubular means;
- flow restricting means mounted in said generally tubular means and operable to cyclically restrict at least a portion of said flow of exhaust gas; and continuously operable venting means operably as sociated with said generally tubular means and operable to maintain a continuously open flow path between said surge chamber means and said atmosphere through which at least a portion of said flow of exhaust gas from said chain saw engine means may continuously pass;
- said noise reducing apparatus including baffle means contained within said surge chamber means and operable to baffle said flow of exhaust gas within said surge chamber means between said exhaust passage means and said acoustic filter means;
- said flow restricting means being telescopingly associated with said tubular means and supported by said noise reducing apparatus for substantially unimpeded reciprocating movement relative to said tubular means;
- said flow restricting means including wall means telescopingly received with said tubular means and operable to cooperate with said lateral wall means and interior passage means of said tubular means and define generally annular passage means within said interior passage means operable to deflect a flow of exhaust gas passing transversely of said lateral
- support means including said outlet passage means, telescopingly mounting said flow restricting means for substantially unimpeded cyclic movement.
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Abstract
Description
Claims (8)
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US434654A US3921290A (en) | 1972-01-25 | 1974-01-18 | Chain saw with cyclically restricted and continuously vented acoustic filtering |
CA210,485A CA1002856A (en) | 1974-01-18 | 1974-10-01 | Chain saw with cyclically restricted and continuously vented acoustic filtering |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US00220632A US3798769A (en) | 1972-01-25 | 1972-01-25 | Apparatus for reducing the operating noise of a chain saw |
US434654A US3921290A (en) | 1972-01-25 | 1974-01-18 | Chain saw with cyclically restricted and continuously vented acoustic filtering |
Publications (1)
Publication Number | Publication Date |
---|---|
US3921290A true US3921290A (en) | 1975-11-25 |
Family
ID=26915044
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
US434654A Expired - Lifetime US3921290A (en) | 1972-01-25 | 1974-01-18 | Chain saw with cyclically restricted and continuously vented acoustic filtering |
Country Status (1)
Country | Link |
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US (1) | US3921290A (en) |
Cited By (6)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2929965A1 (en) * | 1978-07-31 | 1980-02-21 | Nat Union Electric Corp | IC engine driven portable chain saw - has cooling fan feeding air into exhaust gas mixing chamber before exhaust reaches outlet |
FR2479894A1 (en) * | 1979-06-25 | 1981-10-09 | Beaird Poulan Div | SILENCER FOR INTERNAL COMBUSTION ENGINE |
US4482028A (en) * | 1982-05-25 | 1984-11-13 | Kioritz Corporation | Muffler for internal combustion engine |
US4538701A (en) * | 1982-07-19 | 1985-09-03 | Tecumseh Products Company | Muffler |
EP0197487A2 (en) * | 1985-03-29 | 1986-10-15 | Komatsu Zenoah Co. | Portable engine unit |
EP2192284A1 (en) * | 2007-09-20 | 2010-06-02 | Hino Motors Ltd. | Exhaust purification apparatus |
Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
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US2214894A (en) * | 1936-12-12 | 1940-09-17 | Gen Motors Corp | Resonator silencer |
US3106985A (en) * | 1960-12-05 | 1963-10-15 | Kenneth J Recupito | Muffler apparatus |
US3404749A (en) * | 1967-03-27 | 1968-10-08 | American Lincoln Corp | Chain saw muffler |
US3703938A (en) * | 1971-04-06 | 1972-11-28 | Nelson Muffler Corp | Exhaust muffler |
-
1974
- 1974-01-18 US US434654A patent/US3921290A/en not_active Expired - Lifetime
Patent Citations (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2214894A (en) * | 1936-12-12 | 1940-09-17 | Gen Motors Corp | Resonator silencer |
US3106985A (en) * | 1960-12-05 | 1963-10-15 | Kenneth J Recupito | Muffler apparatus |
US3404749A (en) * | 1967-03-27 | 1968-10-08 | American Lincoln Corp | Chain saw muffler |
US3703938A (en) * | 1971-04-06 | 1972-11-28 | Nelson Muffler Corp | Exhaust muffler |
Cited By (12)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2929965A1 (en) * | 1978-07-31 | 1980-02-21 | Nat Union Electric Corp | IC engine driven portable chain saw - has cooling fan feeding air into exhaust gas mixing chamber before exhaust reaches outlet |
FR2479894A1 (en) * | 1979-06-25 | 1981-10-09 | Beaird Poulan Div | SILENCER FOR INTERNAL COMBUSTION ENGINE |
US4482028A (en) * | 1982-05-25 | 1984-11-13 | Kioritz Corporation | Muffler for internal combustion engine |
US4538701A (en) * | 1982-07-19 | 1985-09-03 | Tecumseh Products Company | Muffler |
EP0197487A2 (en) * | 1985-03-29 | 1986-10-15 | Komatsu Zenoah Co. | Portable engine unit |
US4727828A (en) * | 1985-03-29 | 1988-03-01 | Komatsu Zenoah Company | Portable engine unit |
EP0197487A3 (en) * | 1985-03-29 | 1989-11-29 | Komatsu Zenoah Co. | Portable engine unit |
EP2192284A1 (en) * | 2007-09-20 | 2010-06-02 | Hino Motors Ltd. | Exhaust purification apparatus |
US20100196219A1 (en) * | 2007-09-20 | 2010-08-05 | Hino Motors, Ltd. | Exhaust emission control device |
EP2192284A4 (en) * | 2007-09-20 | 2011-06-15 | Hino Motors Ltd | Exhaust purification apparatus |
US8377383B2 (en) | 2007-09-20 | 2013-02-19 | Hino Motors, Ltd. | Exhaust emission control device |
CN101802356B (en) * | 2007-09-20 | 2014-08-06 | 日野自动车株式会社 | Exhaust purification apparatus |
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