US3823795A - Air tool muffler - Google Patents

Air tool muffler Download PDF

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Publication number
US3823795A
US3823795A US00365199A US36519973A US3823795A US 3823795 A US3823795 A US 3823795A US 00365199 A US00365199 A US 00365199A US 36519973 A US36519973 A US 36519973A US 3823795 A US3823795 A US 3823795A
Authority
US
United States
Prior art keywords
air
motor
housing
exhaust passage
passage means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00365199A
Other languages
English (en)
Inventor
D Fleigle
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Black and Decker Corp
Original Assignee
Black and Decker Manufacturing Co
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Black and Decker Manufacturing Co filed Critical Black and Decker Manufacturing Co
Priority to US00365199A priority Critical patent/US3823795A/en
Priority to CA197,586A priority patent/CA1010732A/en
Priority to DE2422145A priority patent/DE2422145A1/de
Priority to FR7417018A priority patent/FR2231481B1/fr
Priority to IT23122/74A priority patent/IT1012771B/it
Priority to CH735374A priority patent/CH577355A5/xx
Priority to GB2371574A priority patent/GB1441725A/en
Priority to JP6033774A priority patent/JPS5418786B2/ja
Application granted granted Critical
Publication of US3823795A publication Critical patent/US3823795A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • 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
    • F01N13/001—Exhaust gas flow channels or chambers being at least partly formed in the structural parts of the engine or machine
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25B—TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING OR HOLDING
    • B25B21/00—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose
    • B25B21/02—Portable power-driven screw or nut setting or loosening tools; Attachments for drilling apparatus serving the same purpose with means for imparting impact to screwdriver blade or nut socket
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
    • B25F—COMBINATION OR MULTI-PURPOSE TOOLS NOT OTHERWISE PROVIDED FOR; DETAILS OR COMPONENTS OF PORTABLE POWER-DRIVEN TOOLS NOT PARTICULARLY RELATED TO THE OPERATIONS PERFORMED AND NOT OTHERWISE PROVIDED FOR
    • B25F5/00—Details or components of portable power-driven tools not particularly related to the operations performed and not otherwise provided for
    • 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

  • ABSTRACT A pneumatic portable power tool such as an impact wrench is disclosed which incorporates an improved air exhaust passage and muffler.
  • the tool is of the pistol-griptype and the exhaust passage is provided immediately above the trigger and handle, the exhaust air being directed away from the operator.
  • An improved muffler incorporating several noise-reduction features in a simplified construction is provided in the passage.
  • the present invention is directed to portable power tools of the pneumatic type and is specifically directed to tools of the pistol grip type wherein the motor and output shaft are substantially aligned and the operator handle extends perpendicularly therefrom.
  • Pneumatic power tools offer many advantages to industrial and commercial users in terms of power-toweight ratios and efficiency.
  • a major disadvantage of such tools has been the high noise level generated during operation.
  • the noise produced by such tools is the inherent result of allowing high velocity air to exhaust from the tool into the atmosphere without significant provision for m'uffling.
  • an improved pneumatic power tool which includes a rotary motor adapted to be connected to a source of pressurized fluid and an output device driven by the motor.
  • the power tool may comprise an impact wrench with a generallyaxially aligned motor and output shaft and a handle extending at an angle thereto.
  • the handle includes an inlet path controlled by a trigger member. Fluid is exhausted from the motor into a region formed within the tool housing.
  • the region is subdivided into two separate chambers by an intermediate barrier having a plurality of small apertures therein. The fluid passes from one of these chambers through the apertures into the other and then is exhausted into the atmosphere through a further wall also provided with small apertures. This system effectively reduces the noise of the exhaust stream without interfering with the efficiency of the motor.
  • the exhaust stream is passed through two expansion chambers and through two diffusionbarriers to reduce the noise.
  • multiple muffling elements are formed by a separate muffler subassembly which is inserted and mounted within a large chamber formed in the tool housing.
  • FIG. 1 is a side elevation, partially broken away, of a portable pneumatic power tool in accord with the present invention
  • FIG. 2 is a front elevation of the tool of FIG. 1;
  • FIG. 3 is an enlarged front elevation of a section of FIG. 2;
  • FIG. 4 is a cross sectional view taken along the lines
  • FIG. 5 is a perspective view, partially broken away, of the muffler insert of FIG; 4;
  • FIG. 6 is a rear perspective view of the insert of FIG. 4.
  • a portable pneumatic impact wrench 10 is shown by way of illustration.
  • the wrench includes an inlet bushing 11 for receiving a supply hose from a source of compressed air, a handle 12 through which the inlet air passes and a trigger 13 which controls the flow of air to the tool.
  • the tool further includes an air motor comprising a rotor and a plurality of vanes such as that shown at 14 which is adapted to be driven by the compressed air and which is coupled via a shaft and a suitable impact mechanism to an output member 15.
  • the air stream leaving the motor vanes l4 passes through an aperture 16 into a chamber 17. Since the tool housing is conventionally a metal casting, the chamber 17 may be formed at the time of casting the overall housing.
  • a muffler insert 20 is provided within the chamber 17.
  • the muffling insert which can be seen in the frontal view of FIG. 2, preferably comprises a separately formed subassembly which is inserted during manufacture of the tool and which may be retained in place by a screw 21.
  • FIGS. 3, 4 and 5 illustrate the muffling insert 20 more clearly.
  • this insert comprises a molded plastic cartridge provided at the time of molding with a back wall 22 and side walls 23 defining an intermediate expansion chamber and a separately molded front wall 24 which is suitably .affixed to the cartridge.
  • the assembly is provided with an aperture 25 for receiving the screw 21.
  • the rear of the cartridge is shaped as shown at 26 to fit over a housing boss 27 which includes a threaded aperture for receiving the screw 21.
  • the combination of the muffiing insert 20 and chamber 17 provides a simple and easily manufactured muffiing arrangement which actually embodies several desirable noise-reducing features.
  • the two expansion chambers one of which is formed by the chamber 17 and the back wall 22 of the cartridge and the other which is formed internally of the cartridge between its back wall 2 and front wall 24, are sized so as to attenuate at overlapping noise frequency bands and thus reduce the volume of noise generated at those frequencies.
  • the walls 22 and 24 of the muffiing insert are provided with a large number of small holes 28. In each case, the air passing through these walls is formed into a plurality of small jets. This 3 greatly increases the boundary area between the jets entering the downstream region and the air in that region.
  • the noise generated by a jet of air passing through an aperture has been found to be inversely proportional to the boundary area and thus, the provision of these walls with multiple apertures substantially reduces the noise generated.
  • a further element of this system is the relative pressure ratios across each of these walls. If the downstream pressure is too low relative to the upstream pressure, the flow through the apertures may reach sonic velocities which causes a sub-,
  • back wall 22 has a thickness of about 0.10'inch and-the diameter-of the holes in the back wall is approximately 0.05 inch.
  • the front wall 24 has a thickness of 0.15 inch and the apertures therein are also about 0.05 inch. More generally, it is preferred that the length to diameter ratio of the apertures be between about one-to-one and four-to-one. The number of apertures, of course, is large enough so that the air flow out of the motor is not seriously restricted. This structure will provide maximum air flow with minimum noise generation.
  • a portable pneumatic power tool comprising a housing; a rotary air motor enclosed within said housing; a handle portion extending from said housing; ex-
  • haust passage means for air flow exhausting from said motor between said handle portion and said air motor, said exhaust passage means comprising a first attenuation chamber in the path of said air flow; a second attenuation chamber also in the path of said air flow; a first apertured wall separating and partially defining said first and second chambers; and a second apertured wall at the interface between said second chamber and atmosphere.
  • a portable pneumatic power tool as claimed in claim 1 wherein said motor rotates about an axis; wherein said handle extends at a substantially right angle tothe axis of said motor; and wherein said exhaust passage means extends in a direction substan- 4 i tially parallel to that of said motor axis to direct exhausting air away from an operator of said tool.
  • a portable pneumatic power tool as claimed in claim 2 wherein said housing comprises a cast body including a tubular portion enclosing said motor; wherein said exhaust passage means comprises a cavity in said cast body, said cavity extending along one side of said tubular portion; and wherein said handle extends outwardly from said housing at said cavity.
  • a portable pneumatic power tool comprising a housing; a rotary air motor enclosed within saidhousing;air inlet passage means for providing a supply of pressurized air tosaid motor; handlemeans extending at one side of said motor; and exhaust passage means for air exhaustingfrom said motor, said exhaust passage means comprising a cavity in said housing betweensaid motor and said handle and including a first attenuation chamber sized to further reduce the sound intensity of air exhausting from said motor, a first apertured wall, a second attenuation chamber sized to further re- I Jerusalem the sound intensity of air exhausting from said motor, and a second apertured wall, said second wall lying between said second chamber and the atmosphere.
  • a portable pneumatic power tool comprising a housing; a rotary air motor enclosed within said housing; a handle portion extending to one side from said housing; exhaust passage means for air flow exhausting from said motor between saidhandle portion and said air motor, said exhaust passage means comprising a first chamber in the-path of said air flow; a second chamber also in the path of said airflow; a first aper-.
  • first and second chambers being sized to prevent noise generation upon passage of exhaust air therethrough and said apertures in said first and said second walls having a length-to-effective diameter ratio in the range of from one-to-one to four-to-one.
  • a portable pneumatic power tool comprising a housing; an air motor enclosed within said housing; air inlet passage means for providing a supply of pressurized air to said motor; and exhaust passage means com prising a cavity in said housing for air exhausting from said motor, said exhaust passage means defining a first

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • General Engineering & Computer Science (AREA)
  • Portable Power Tools In General (AREA)
  • Exhaust Silencers (AREA)
  • Percussive Tools And Related Accessories (AREA)
  • Self-Closing Valves And Venting Or Aerating Valves (AREA)
  • Portable Nailing Machines And Staplers (AREA)
US00365199A 1973-05-30 1973-05-30 Air tool muffler Expired - Lifetime US3823795A (en)

Priority Applications (8)

Application Number Priority Date Filing Date Title
US00365199A US3823795A (en) 1973-05-30 1973-05-30 Air tool muffler
CA197,586A CA1010732A (en) 1973-05-30 1974-04-16 Air tool muffler
DE2422145A DE2422145A1 (de) 1973-05-30 1974-05-08 Pneumatisch angetriebene, tragbare werkzeugmaschine
FR7417018A FR2231481B1 (enrdf_load_stackoverflow) 1973-05-30 1974-05-16
IT23122/74A IT1012771B (it) 1973-05-30 1974-05-22 Silenziatore per utensili ad aria
CH735374A CH577355A5 (enrdf_load_stackoverflow) 1973-05-30 1974-05-29
GB2371574A GB1441725A (en) 1973-05-30 1974-05-29 Pneumatic power tool
JP6033774A JPS5418786B2 (enrdf_load_stackoverflow) 1973-05-30 1974-05-30

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00365199A US3823795A (en) 1973-05-30 1973-05-30 Air tool muffler

Publications (1)

Publication Number Publication Date
US3823795A true US3823795A (en) 1974-07-16

Family

ID=23437876

Family Applications (1)

Application Number Title Priority Date Filing Date
US00365199A Expired - Lifetime US3823795A (en) 1973-05-30 1973-05-30 Air tool muffler

Country Status (8)

Country Link
US (1) US3823795A (enrdf_load_stackoverflow)
JP (1) JPS5418786B2 (enrdf_load_stackoverflow)
CA (1) CA1010732A (enrdf_load_stackoverflow)
CH (1) CH577355A5 (enrdf_load_stackoverflow)
DE (1) DE2422145A1 (enrdf_load_stackoverflow)
FR (1) FR2231481B1 (enrdf_load_stackoverflow)
GB (1) GB1441725A (enrdf_load_stackoverflow)
IT (1) IT1012771B (enrdf_load_stackoverflow)

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5020607A (en) * 1989-12-13 1991-06-04 Sentivan Robert R Lug-removing pneumatic impact-gun air blast-deflector
US6062323A (en) * 1998-07-21 2000-05-16 Snap-On Tools Company Pneumatic tool with increased power capability
WO2000047872A1 (en) * 1999-02-11 2000-08-17 Snap-On Tools Company Pneumatic tool and air deflector boot therefor
US20040055815A1 (en) * 1998-01-13 2004-03-25 Sterling Robert E. Muffler for pneumatic hand tool
US20050103566A1 (en) * 1998-01-13 2005-05-19 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US20060237081A1 (en) * 2005-04-21 2006-10-26 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US20080035419A1 (en) * 2006-05-09 2008-02-14 Justin Moore Muffler diffuser
US20080047778A1 (en) * 2006-05-19 2008-02-28 Tranmax Machinery Co., Ltd. Exhaust end structure of a straight pneumatic wrench
US20080099225A1 (en) * 2006-10-25 2008-05-01 Sunmatch Industrial Co., Ltd. Pen-type pneumatic tool having a manual airflow control knob
DE102008028938A1 (de) * 2008-03-28 2009-10-01 TRANMAX MACHINERY Co., Ltd., Taiping Druckluftwerkzeug mit Lärmminderungsfunktion
US9849575B2 (en) * 2011-01-18 2017-12-26 Dino Paoli S.R.L. Pneumatic screwer

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002089227A (ja) * 2000-09-13 2002-03-27 Kuken:Kk エアツールにおける消音装置

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2073480A (en) * 1934-10-04 1937-03-09 Ingersoll Rand Co Muffling device
US2169359A (en) * 1938-12-05 1939-08-15 Barnes & Jones Inc Orifice device
GB810398A (en) * 1957-01-22 1959-03-18 Siemens Edison Swan Ltd Silencing device for pneumatically operated hand tools
US2950775A (en) * 1958-01-13 1960-08-30 Aro Equipment Corp Exhaust noise reducing and air diffusing means for pneumatic motors
US2966138A (en) * 1958-05-12 1960-12-27 Robert C Quackenbush Muffler construction for portable pneumatic tool
US3384200A (en) * 1967-03-16 1968-05-21 Gardner Denver Co Exhaust muffler for pneumatic tool

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4117998Y1 (enrdf_load_stackoverflow) * 1964-05-22 1966-08-20
US3407885A (en) * 1967-03-10 1968-10-29 Reed International Inc Air balance for impact wrenches
JPS4736623U (enrdf_load_stackoverflow) * 1971-04-28 1972-12-22

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2073480A (en) * 1934-10-04 1937-03-09 Ingersoll Rand Co Muffling device
US2169359A (en) * 1938-12-05 1939-08-15 Barnes & Jones Inc Orifice device
GB810398A (en) * 1957-01-22 1959-03-18 Siemens Edison Swan Ltd Silencing device for pneumatically operated hand tools
US2950775A (en) * 1958-01-13 1960-08-30 Aro Equipment Corp Exhaust noise reducing and air diffusing means for pneumatic motors
US2966138A (en) * 1958-05-12 1960-12-27 Robert C Quackenbush Muffler construction for portable pneumatic tool
US3384200A (en) * 1967-03-16 1968-05-21 Gardner Denver Co Exhaust muffler for pneumatic tool

Cited By (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5020607A (en) * 1989-12-13 1991-06-04 Sentivan Robert R Lug-removing pneumatic impact-gun air blast-deflector
US7216739B2 (en) * 1998-01-13 2007-05-15 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US20040055815A1 (en) * 1998-01-13 2004-03-25 Sterling Robert E. Muffler for pneumatic hand tool
US20050103566A1 (en) * 1998-01-13 2005-05-19 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US6926117B2 (en) * 1998-01-13 2005-08-09 Exhaust Technologies, Inc. Muffler for pneumatic hand tool
US6062323A (en) * 1998-07-21 2000-05-16 Snap-On Tools Company Pneumatic tool with increased power capability
WO2000047872A1 (en) * 1999-02-11 2000-08-17 Snap-On Tools Company Pneumatic tool and air deflector boot therefor
US6199383B1 (en) 1999-02-11 2001-03-13 Snap-On Tools Company Pneumatic tool and air deflector boot therefor
AU751917B2 (en) * 1999-02-11 2002-08-29 Snap-On Tools Company Pneumatic tool and air deflector boot therefor
US20060237081A1 (en) * 2005-04-21 2006-10-26 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US7549509B2 (en) 2005-04-21 2009-06-23 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US9062679B2 (en) 2005-04-21 2015-06-23 Ingersoll-Rand Company Double throat pulsation dampener for a compressor
US20080035419A1 (en) * 2006-05-09 2008-02-14 Justin Moore Muffler diffuser
US20080047778A1 (en) * 2006-05-19 2008-02-28 Tranmax Machinery Co., Ltd. Exhaust end structure of a straight pneumatic wrench
US20080099225A1 (en) * 2006-10-25 2008-05-01 Sunmatch Industrial Co., Ltd. Pen-type pneumatic tool having a manual airflow control knob
DE102008028938A1 (de) * 2008-03-28 2009-10-01 TRANMAX MACHINERY Co., Ltd., Taiping Druckluftwerkzeug mit Lärmminderungsfunktion
US20090242225A1 (en) * 2008-03-28 2009-10-01 Tranmax Machinery Co., Ltd. Pneumatic tool with noise reduction function
US9849575B2 (en) * 2011-01-18 2017-12-26 Dino Paoli S.R.L. Pneumatic screwer

Also Published As

Publication number Publication date
GB1441725A (en) 1976-07-07
CH577355A5 (enrdf_load_stackoverflow) 1976-07-15
JPS5020381A (enrdf_load_stackoverflow) 1975-03-04
FR2231481A1 (enrdf_load_stackoverflow) 1974-12-27
CA1010732A (en) 1977-05-24
JPS5418786B2 (enrdf_load_stackoverflow) 1979-07-10
IT1012771B (it) 1977-03-10
DE2422145A1 (de) 1975-02-13
FR2231481B1 (enrdf_load_stackoverflow) 1977-10-28

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