US3354986A - Muffler with frusto-conical baffle members spaced along central tube - Google Patents

Muffler with frusto-conical baffle members spaced along central tube Download PDF

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US3354986A
US3354986A US473631A US47363165A US3354986A US 3354986 A US3354986 A US 3354986A US 473631 A US473631 A US 473631A US 47363165 A US47363165 A US 47363165A US 3354986 A US3354986 A US 3354986A
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members
tube
casing
frusto
muffler
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US473631A
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William A Moss
Rose E Griffin
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JAMES D PARKERSON
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JAMES D PARKERSON
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust 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
    • F01N13/18Construction facilitating manufacture, assembly, or disassembly
    • F01N13/1838Construction facilitating manufacture, assembly, or disassembly characterised by the type of connection between parts of exhaust or silencing apparatus, e.g. between housing and tubes, between tubes and baffles
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00Silencing apparatus characterised by method of silencing
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N1/00Silencing apparatus characterised by method of silencing
    • F01N1/08Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling
    • F01N1/083Silencing apparatus characterised by method of silencing by reducing exhaust energy by throttling or whirling using transversal baffles defining a tortuous path for the gases or successively throttling gas flow
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust 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
    • F01N13/18Construction facilitating manufacture, assembly, or disassembly
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N13/00Exhaust 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
    • F01N13/18Construction facilitating manufacture, assembly, or disassembly
    • F01N13/1838Construction facilitating manufacture, assembly, or disassembly characterised by the type of connection between parts of exhaust or silencing apparatus, e.g. between housing and tubes, between tubes and baffles
    • F01N13/1844Mechanical joints
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2450/00Methods or apparatus for fitting, inserting or repairing different elements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2450/00Methods or apparatus for fitting, inserting or repairing different elements
    • F01N2450/22Methods or apparatus for fitting, inserting or repairing different elements by welding or brazing
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2470/00Structure or shape of gas passages, pipes or tubes
    • F01N2470/02Tubes being perforated
    • F01N2470/04Tubes being perforated characterised by shape, disposition or dimensions of apertures
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2470/00Structure or shape of gas passages, pipes or tubes
    • F01N2470/20Dimensional characteristics of tubes, e.g. length, diameter
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2490/00Structure, disposition or shape of gas-chambers
    • F01N2490/08Two or more expansion chambers in series separated by apertured walls only
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01NGAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL COMBUSTION ENGINES
    • F01N2530/00Selection of materials for tubes, chambers or housings
    • F01N2530/24Sintered porous material, e.g. bronze, aluminium or the like

Definitions

  • the present invention relates to mufiiers for internal combustion engines and more particularly to a novel and improved muffler structure which is highly effective in reducing unwanted noise generated by exhaust gasses from an internal combustion engine while creating only a small amount of back pressure thereby enabling efiicient, economical operation of an internal combustion engine.
  • Still another object of this invention is to provide a muffler in accordance with the preceding objects which is highly compact with minimized cross sectional area facilitating its compact mounting on an automobile or other apparatus with which it is used.
  • the mufiler comprises an elongated tubular,.imperforate casing defining an outlet opening and an inlet opening aligned therewith.
  • a tu-be extends substantially axially of the casing and has a closed end spaced within and apart from the outlet opening.
  • a plurality of frusto-conical members surround the tube and extend between the tube and the casing to define at least two overlapping-gas expansion chambers. At least two of the plurality of frusto-conical members are spaced apart intermediate the outlet and inlet openings to define a flow chamber of larger volume than either of the expansion chambers and arranged in axial alignment with the expansion chambers.
  • Apertures are provided in the frustoconical members and in the centrally located tube to provide a gas flow passageway from a portion of the tube adjacent the inlet opening through the expansion chambers and the flow chamber to the outlet opening.
  • two overlapped frustoconical members are provided at one end of the ca ing and two frusto-conical members are provided at the other end with a space extending between the pairs of frustoconical members.
  • This space acts as a flow chamber to decrease muifier back pressure and thereby permit economical operation of the internal combustion engine with which the muffler is used.
  • FIG. 1 is a cross sectional view taken on a vertical plane through the center of a preferred embodiment of the muffler of this invention
  • FIG. 2 is a side view of an element thereof;
  • FIG. 3 is a side view of another element thereof; and
  • FIG. 4 is a rear view of a frusto-conical element as shown in FIG. 2 with the element of FIG. 3 positioned therein.
  • a preferred embodiment of the muffler of this invention is illustrated at 10 and comprises an imper'forate casing 11 containing an inner axially aligned tube 12 having surrounding frustoc nical members 13, 14, 15 and 16 extending from the tube 12 to the inner surface of the casing 11.
  • the frustoconical members are arranged to extend axially of the casing as best shown in FIG. 1 dividing the casing into expansion chambers 17 and 18 spaced from a forward expansion chamber 19 with a flow chamber 20 intermediate thereof.
  • the imperforate casing 11 is preferably a cylindrical pipe composed of a high temperature resistant material such as solid copper pipe type K. Means such as threads 22 and 23 are carried at inlet and outlet ends of the casing respectively. Since the casing 11 is circular in cross section, and all flow through the elongated mufiler is substantially from end to end thereof, a minimum cross sectional area for the outer configuration of the muffier may be maintained. Suitable adapters (not shown) are provided for the ends of the rnufiier to attach an exhaust pipe from the manifold on a threaded flange with the exhaust pipe abutting the rear end of the central tube 1.2 and with a tail pipe attached to the outlet end 23 through a suitable reducing flange.
  • casing pipe 11 preferably has an inside diameter of 2% inches with an outside diameter of 2 /8 inches being a solid copper seamless pipe having a length of approximately 21 inches.
  • the inner tube 12 is preferably a solid copper pipe which extends axially of and within the outer casing having a closed forward end pinched together at 24 as best seen in FIG. 3.
  • the pinched together end 24 is provided with crossed plates 25 and 26 which act to center the pipe within outer tube 11 as will be described. Plates 25 and 26 are welded or otherwise fixed to the pinched end 24,
  • the copper pipe 12 of the preferred embodiment has an outside diameter of inch and a series of perforations extending from /2 inch of its end adjacent the intake end of the casing in a first and second group towards the closed end.
  • Perforations 27 lie within the frusto-conical member 14 and preferably comprise four rows of five circular openings with the rows spaced approximately about the circumference of the pipe.
  • the group of perforations 28 preferably comprises four rows of seven openings aligned with the rows of group 27 with all of the openings preferably having a diameter of Ms inch.
  • the particular material of the tube 12 as well as its dimensions may vary considerably depending upon the particular size engine with which the mufiler is used as may the dimensions of other elements of the mufflers while their relative dimensions to each other are preferably substantially as described.
  • the spacing, number, size and location of the holes 27 and 23 within baffies 13 and 14 is important for optimum operation of the invention.
  • the frusto-conical members 13, 14, 15 and 16 act as battles to provide expansion chambers and a flow chamber within the mufiler.
  • Each of the baffies preferably has a large or base end outside diameter approximately inch greater that the inner diameter of the casing 11 and a small end inner diameter approximately 4 inch less than the outside diameter of pipe 12.
  • the baflle members may be made of any heat resistant material such as 16 ounce copper and can be formed with a welded or soldered seam.
  • Each bafile preferably has a length of approximately 4 inches in the preferred embodiment with the extreme end baffle nearest the intake end having a length approximately 10% longer.
  • Each of the baflle members with the exception of the two central members are over- 3 lapped or inserted into one another for a distance of approximately 1 inch.
  • the baflles contain a series of perforations which are preferably elongated slots extending in thirteen rows equally spaced about the circumference thereof with approximately 5 slots of .07 square inch area in each baffle row.
  • the smaller diameter opening of the baflle members are soldered or welded to the tube 12.
  • the forward baffle member 16 is provided with a closed end cap formed by end 24 and the plates 25 and 26 may be welded or tightly fit within the inside of outer tube 11 as best shown in FIGS. 1 and 4 to centrally locate both the baffle and the pipe within the tubular casing.
  • the perforations extend within the baffles approximately inch from the casing 11 and approximately /8 inch from the tube 12. While these dimensions are not absolute as previously described, they give best results in the preferred embodiment of the invention.
  • baffle members 13, 14, 15 and 16 are preferably force fit over pipe 12.
  • metallic baffle members are welded or braised to pipe 12.
  • the assembled baffle members and pipe are then positioned in the casing 11 where they are held in place by a force fit since the diameters of the baffle members and plates 25 and 26 are slightly greater than the casing 11.
  • the baffle n1embers are preferably formed of a relatively thin resilient metal such as copper or a copper alloy. Due to the force fit assembly the mufiier can be easily taken apart for cleaning when desired and later reassembled.
  • baffle 14 and 15 The spacing between baffle 14 and 15 is critical and provides for an enlarged flow passageway which is believed to create a partial vacuum during operation of the device to enhance flow of gasses from the expansion chambers 17 and 18 through the muffler. It is important that this chamber be formed with a spacing between facing ends of adjacent baffles greater than one half the axial length of the shortest baffle employed.
  • the flow passageway includes the space between the outer surface of the concentric tube 12 and the inner surface of the outer wall of casing 11.
  • the axial distance that the flow chamber 20 extends between ends of its adjacent bafile members is 3% inch.
  • the ratio between the axial uninterrupted length of the flow chamber 20 between its adjacent bafiies, to the distance represented by the length of an adjacent baffie plus the length of the flow chamber is approximately 3% to 7%,.
  • gasses from the manifold of an internal combustion engine are passed into the inner tube 12 in the direction of the arrows shown. Some of these gasses will go immediately into the expansion chambers while the greater percentage of the gasses will flow towards the forward end to create a zone of churning gasses within the pipe in the forward batfle member 16. This churning action causes more of the gasses from the engine to flow through openings 27 and 28 directly into the expansion chambers 17 and 18.
  • the baffies inhibit the sudden discharge of expanding gasses by means of redirecting, reflecting and controlling the passage of gasses through the muffler.
  • a compact muffler comprising an elongated tubular, imperforate, casing defining an inlet opening and an outlet opening aligned therewith,
  • At least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber of larger volume than either of said expansion chambers and arranged in axial alignment therewith,
  • said apertures defined by said tube being positioned within one of said pairs of frusto-conical members spaced substantially adjacent said inlet opening.
  • apertures comprise two groupings of openings with one group in each of the frusto-conical members of said pair spaced substantially adjacent said inlet opening.
  • a compact mutfier comprising an elongated circular, imperforate casing defining an inlet opening and an aligned outlet Opening,
  • a plurality of frusto-conical members surrounding said tube and defining at least two overlapping expansion chambers and acting as baffle means with apertures provided in said members interconnecting said 60 chambers,
  • At least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber extending axially of said casing between said tube and said casing,
  • a compact mufl ler in accordance with claim 5 wherein four frusto-conical members are provided with two of said frusto-conical members being spaced apart from two others of said frusto-conical members to define said flow chamber whereby exhaust gasses entering said tube at said inlet opening flow through said two baffle members positioned substantially adjacent said inlet opening to said flow chamber and subsequently through said two members positioned adjacent said outlet opening whereby said members act as bafiies to inhibit the sudden discharge of expanding exhaust gasses by redirecting, reflecting and controlling the passage of said gasses through said mufiler.
  • said closed end of said tube is pinched together and carries a plurality of plate means for positioning said tube centrally of said casing.
  • a muffler for use in conjunction with an engine which normally produces exhaust gasses,
  • said mufiler comprising an elongated casing defining an inlet opening and an outlet opening aligned therewith, a tube extending substantially axially of said casing and having a closed end spaced within and apart from said outlet opening and an opened end positioned within said casing spaced from said inlet opening, a plurality of frusto-conical bafiie members extending from said tube to said casing with said bafile members defining a plurality of apertures to provide an axially extending passageway through said muffler,
  • At least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber with others of said bafile members overlapping each other to provide expansion chambers,
  • said tube defining two groups of apertures each lying in separate bafile members near said inlet opening to provide for passage of exhaust gasses from said groups through said expansion chambers and said flow chamber to said outlet opening.

Description

Nov. 28, 1967 I w oss ETAL 3,354,986
MUFFLER WITH FRUSTO-CONICAL BAFFLE MEMBERS SPACED ALONG CENTRAL TUBE Filed July 21, 1965 IIII n o 11 f; 9 2 E n LL 0 O O o ,\m o
0 I M r 2 l o o 3 Z 0 II (I?! v 9' LL. C) Q E INVENTORS WILLIAM A MOSS A ROSE E. GRIFFIN ATTO RN EYS Patented Nov. 28, 1967 3,354,986 MUFFLER WITH FRUSTO-CONICAL RAFFLE MEMBERS SPACED ALONG CENTRAL TUBE William A. Moss and Rose E. Grifiin, Lafayette, La., assignors, by direct and mesne assignments, of fifty percent to said Moss, twenty-five percent to James D. Parkerson, and twenty-five percent to J. Arthur Roy, all of Lafayette, La.
Filed July 21, 1965, Ser. No. 473,631 9 Claims. (Cl. 18157) The present invention relates to mufiiers for internal combustion engines and more particularly to a novel and improved muffler structure which is highly effective in reducing unwanted noise generated by exhaust gasses from an internal combustion engine while creating only a small amount of back pressure thereby enabling efiicient, economical operation of an internal combustion engine.
Various muffler designs are well known in the internal combustion engine art. These mufflers are normally constructed to minimize back pressure and noise due to expanding gasses. Many of these mufflers employ divided flow passageways for exhaust gasses but all have met with certain problems. In some cases back pressure produced by such mufflers is unnecessarily high and/ or noise reduction is not maximized.
It is an important object of the present invention to provide a new and improved mufiier construction which enables quiet, economical operation of an internal combustion engine. Another important object of this invention is to provide a muffler in accordance with the preceding object which can easily be taken apart for cleaning when desired and reassembled with ease.
Still another object of this invention is to provide a muffler in accordance with the preceding objects which is highly compact with minimized cross sectional area facilitating its compact mounting on an automobile or other apparatus with which it is used.
According to the invention, the mufiler comprises an elongated tubular,.imperforate casing defining an outlet opening and an inlet opening aligned therewith. A tu-be extends substantially axially of the casing and has a closed end spaced within and apart from the outlet opening. A plurality of frusto-conical members surround the tube and extend between the tube and the casing to define at least two overlapping-gas expansion chambers. At least two of the plurality of frusto-conical members are spaced apart intermediate the outlet and inlet openings to define a flow chamber of larger volume than either of the expansion chambers and arranged in axial alignment with the expansion chambers. Apertures are provided in the frustoconical members and in the centrally located tube to provide a gas flow passageway from a portion of the tube adjacent the inlet opening through the expansion chambers and the flow chamber to the outlet opening.
In the preferred embodiment, two overlapped frustoconical members are provided at one end of the ca ing and two frusto-conical members are provided at the other end with a space extending between the pairs of frustoconical members. This space acts as a flow chamber to decrease muifier back pressure and thereby permit economical operation of the internal combustion engine with which the muffler is used.
These and other objects, features and advantages of the invention will become apparent from the following specification and attached drawings in which:
FIG. 1 is a cross sectional view taken on a vertical plane through the center of a preferred embodiment of the muffler of this invention;
FIG. 2 is a side view of an element thereof; FIG. 3 is a side view of another element thereof; and FIG. 4 is a rear view of a frusto-conical element as shown in FIG. 2 with the element of FIG. 3 positioned therein.
With reference now to the drawings a preferred embodiment of the muffler of this invention is illustrated at 10 and comprises an imper'forate casing 11 containing an inner axially aligned tube 12 having surrounding frustoc nical members 13, 14, 15 and 16 extending from the tube 12 to the inner surface of the casing 11. The frustoconical members are arranged to extend axially of the casing as best shown in FIG. 1 dividing the casing into expansion chambers 17 and 18 spaced from a forward expansion chamber 19 with a flow chamber 20 intermediate thereof.
The imperforate casing 11 is preferably a cylindrical pipe composed of a high temperature resistant material such as solid copper pipe type K. Means such as threads 22 and 23 are carried at inlet and outlet ends of the casing respectively. Since the casing 11 is circular in cross section, and all flow through the elongated mufiler is substantially from end to end thereof, a minimum cross sectional area for the outer configuration of the muffier may be maintained. Suitable adapters (not shown) are provided for the ends of the rnufiier to attach an exhaust pipe from the manifold on a threaded flange with the exhaust pipe abutting the rear end of the central tube 1.2 and with a tail pipe attached to the outlet end 23 through a suitable reducing flange.
In the specific example of this invention, casing pipe 11 preferably has an inside diameter of 2% inches with an outside diameter of 2 /8 inches being a solid copper seamless pipe having a length of approximately 21 inches.
The inner tube 12 is preferably a solid copper pipe which extends axially of and within the outer casing having a closed forward end pinched together at 24 as best seen in FIG. 3. The pinched together end 24 is provided with crossed plates 25 and 26 which act to center the pipe within outer tube 11 as will be described. Plates 25 and 26 are welded or otherwise fixed to the pinched end 24, The copper pipe 12 of the preferred embodiment has an outside diameter of inch and a series of perforations extending from /2 inch of its end adjacent the intake end of the casing in a first and second group towards the closed end. Perforations 27 lie within the frusto-conical member 14 and preferably comprise four rows of five circular openings with the rows spaced approximately about the circumference of the pipe. The group of perforations 28 preferably comprises four rows of seven openings aligned with the rows of group 27 with all of the openings preferably having a diameter of Ms inch. The particular material of the tube 12 as well as its dimensions may vary considerably depending upon the particular size engine with which the mufiler is used as may the dimensions of other elements of the mufflers while their relative dimensions to each other are preferably substantially as described. The spacing, number, size and location of the holes 27 and 23 within baffies 13 and 14 is important for optimum operation of the invention.
The frusto- conical members 13, 14, 15 and 16 act as battles to provide expansion chambers and a flow chamber within the mufiler. Each of the baffies preferably has a large or base end outside diameter approximately inch greater that the inner diameter of the casing 11 and a small end inner diameter approximately 4 inch less than the outside diameter of pipe 12. The baflle members may be made of any heat resistant material such as 16 ounce copper and can be formed with a welded or soldered seam. Each bafile preferably has a length of approximately 4 inches in the preferred embodiment with the extreme end baffle nearest the intake end having a length approximately 10% longer. Each of the baflle members with the exception of the two central members are over- 3 lapped or inserted into one another for a distance of approximately 1 inch.
The baflles contain a series of perforations which are preferably elongated slots extending in thirteen rows equally spaced about the circumference thereof with approximately 5 slots of .07 square inch area in each baffle row. In some embodiments, the smaller diameter opening of the baflle members are soldered or welded to the tube 12. The forward baffle member 16 is provided with a closed end cap formed by end 24 and the plates 25 and 26 may be welded or tightly fit within the inside of outer tube 11 as best shown in FIGS. 1 and 4 to centrally locate both the baffle and the pipe within the tubular casing. Preferably the perforations extend within the baffles approximately inch from the casing 11 and approximately /8 inch from the tube 12. While these dimensions are not absolute as previously described, they give best results in the preferred embodiment of the invention.
The baffle members 13, 14, 15 and 16 are preferably force fit over pipe 12. In all cases the metallic baffle members are welded or braised to pipe 12. The assembled baffle members and pipe are then positioned in the casing 11 where they are held in place by a force fit since the diameters of the baffle members and plates 25 and 26 are slightly greater than the casing 11. Thus the baffle n1embers are preferably formed of a relatively thin resilient metal such as copper or a copper alloy. Due to the force fit assembly the mufiier can be easily taken apart for cleaning when desired and later reassembled.
The spacing between baffle 14 and 15 is critical and provides for an enlarged flow passageway which is believed to create a partial vacuum during operation of the device to enhance flow of gasses from the expansion chambers 17 and 18 through the muffler. It is important that this chamber be formed with a spacing between facing ends of adjacent baffles greater than one half the axial length of the shortest baffle employed. The flow passageway includes the space between the outer surface of the concentric tube 12 and the inner surface of the outer wall of casing 11. In the preferred embodiment the axial distance that the flow chamber 20 extends between ends of its adjacent bafile members is 3% inch. Preferably the ratio between the axial uninterrupted length of the flow chamber 20 between its adjacent bafiies, to the distance represented by the length of an adjacent baffie plus the length of the flow chamber is approximately 3% to 7%,.
In operation of the muffler of this invention, gasses from the manifold of an internal combustion engine are passed into the inner tube 12 in the direction of the arrows shown. Some of these gasses will go immediately into the expansion chambers while the greater percentage of the gasses will flow towards the forward end to create a zone of churning gasses within the pipe in the forward batfle member 16. This churning action causes more of the gasses from the engine to flow through openings 27 and 28 directly into the expansion chambers 17 and 18. The baffies inhibit the sudden discharge of expanding gasses by means of redirecting, reflecting and controlling the passage of gasses through the muffler. From the expansion chambers 17 and 18 a slight vacuum created in flow chamber 20 will draw the gasses therethrough and allow them to pass onwardly into expansion chamber 19 and out of the muffler through exhaust end 23 to the tailpipe when used. Thus gasses pass through holes 27 and 28, baffles 13, 14, chamber 20, baflle 15 and out through baffle 16. This flow pattern is significant in providing for reduced back pressure within the mufller while allowing rapid expansion and expulsion of gasses. In addition, the multiple chambers provided act to acoustically trap vibrations caused by pulsing of the motor and also act as vibration absorbers to smooth the pulsing out into a smooth pulse pattern thereby deadening the noises created by explosion of the gasses within the motor.
While a specific embodiment .of this invention has been shown and described, it should be understood that many variations thereof are possible. For example, the specific number of battle members can be varied so long as at least one enlarged flow chamber is provided interspaced 5 between baffle members. In some cases where extremely large volumes of exhaust gasses must be muffled and dispersed, two or more flow chambers can be made in a mufiier construction in accordance with the present invention. Similarly larger numbers of expansion chambers can be formed by the use of additional baflle members. Sizes and dimensions may vary preferably consistent with the proportions of the values given.
In view of the many variations possible, this invention is to be limited only by the spirit and scope of the appended claims.
What is claimed is:
1. A compact muffler comprising an elongated tubular, imperforate, casing defining an inlet opening and an outlet opening aligned therewith,
a tube extending substantially axially of said casing and having a closed end spaced Within and apart from said outlet opening,
a plurality of frusto-conical members surrounding said tube and defining at least two overlapping expansion chambers and acting as baffle means,
at least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber of larger volume than either of said expansion chambers and arranged in axial alignment therewith,
and apertures defined by said members and said tube to provide a gas flow passageway from a portion of said tube adjacent said inlet opening through said expansion chambers and said flow chamber to said outlet opening.
2. A compact muffler in accordance with claim 1 wherein two pairs of frusto-conical members are provided,
said apertures defined by said tube being positioned within one of said pairs of frusto-conical members spaced substantially adjacent said inlet opening.
3. A compact mufiler in accordance with claim 1 wherein said frusto-conical members are force fit within said casing whereby said muffler may be easily disassembled for cleaning.
4. A compact muffler in accordance with claim 2 wherein said apertures comprise two groupings of openings with one group in each of the frusto-conical members of said pair spaced substantially adjacent said inlet opening.
5. A compact mutfier comprising an elongated circular, imperforate casing defining an inlet opening and an aligned outlet Opening,
a tube extending substantially concentrically within said casing and having a first closed end substantially adjacent said outlet opening and a second opened end substantially adjacent said inlet opening,
a plurality of frusto-conical members surrounding said tube and defining at least two overlapping expansion chambers and acting as baffle means with apertures provided in said members interconnecting said 60 chambers,
at least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber extending axially of said casing between said tube and said casing,
and apertures defined by said members and said tube to provide a gas flow passageway from a portion of said tube adjacent said inlet opening through said expansion chambers and said flow chamber to said outlet opening.
6. A compact mufl ler in accordance with claim 5 wherein four frusto-conical members are provided with two of said frusto-conical members being spaced apart from two others of said frusto-conical members to define said flow chamber whereby exhaust gasses entering said tube at said inlet opening flow through said two baffle members positioned substantially adjacent said inlet opening to said flow chamber and subsequently through said two members positioned adjacent said outlet opening whereby said members act as bafiies to inhibit the sudden discharge of expanding exhaust gasses by redirecting, reflecting and controlling the passage of said gasses through said mufiler. 7. A muflier in accordance with claim 6 wherein said closed end of said tube is pinched together and carries a plurality of plate means for positioning said tube centrally of said casing.
8. A mufiier in accordance with claim 6 wherein said tube apertures comprise a first and second group,
said first group of apertures being surrounded by one battle and comprising four circumferentially arranged axially extending rows with each row containing seven openings. 9. A muffler for use in conjunction with an engine which normally produces exhaust gasses,
said mufiler comprising an elongated casing defining an inlet opening and an outlet opening aligned therewith, a tube extending substantially axially of said casing and having a closed end spaced within and apart from said outlet opening and an opened end positioned within said casing spaced from said inlet opening, a plurality of frusto-conical bafiie members extending from said tube to said casing with said bafile members defining a plurality of apertures to provide an axially extending passageway through said muffler,
at least two of said plurality of members being spaced apart intermediate said outlet and inlet openings to define a flow chamber with others of said bafile members overlapping each other to provide expansion chambers,
said tube defining two groups of apertures each lying in separate bafile members near said inlet opening to provide for passage of exhaust gasses from said groups through said expansion chambers and said flow chamber to said outlet opening.
References Cited FOREIGN PATENTS 3/ 1921 Great Britain. 2/1925 Great Britain.
ROBERT S. WARD, JR., Primary Examiner.

Claims (1)

1. A COMPACT MUFFLER COMPRISING AN ELONGATED TUBULAR, IMPERFORATE, CASING DEFINING AN INLET OPENING AND AN OUTLET OPENING ALIGNED THEREWITH, A TUBE EXTENDING SUBSTANTIALLY AXIALLY OF SAID CASING AND HAVING A CLOSED END SPACED WITHIN AND APART FROM SAID OUTLET OPENING, A PLURALITY OF FRUSTO-CONICAL MEMBERS SURROUNDING SAID TUBE AND DEFINING AT LEAST TWO OVERLAPPING EXPANSION CHAMBERS AND ACTING AS BAFFLE MEANS, AT LEAST TWO OF SAID PLURALITY OF MEMBERS BEING SPACED APART INTERMEDIATE SAID OUTLET AND INLET OPENINGS TO DEFINE A FLOW CHAMBER OF LARGER VOLUME THAN EITHER OF SAID EXPANSION CHAMBERS AND ARRANGED IN AXIAL ALIGNMENT THEREWITH, AND APERTURES DEFINED BY SAID MEMBERS AND SAID TUBE TO PROVIDE A GAS FLOW PASSAGEWAY FROM A PORTION OF SAID TUBE ADJACENT SAID INLET OPENING THROUGH SAID EXPANSION CHAMBERS AND SAID FLOW CHAMBER TO SAID OUTLET OPENING.
US473631A 1965-07-21 1965-07-21 Muffler with frusto-conical baffle members spaced along central tube Expired - Lifetime US3354986A (en)

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4186819A (en) * 1978-09-28 1980-02-05 Deere & Company Exhaust system for a two-stroke engine
US4595073A (en) * 1984-05-14 1986-06-17 Nelson Industries Inc. Plug-type muffler section
DE102004007756A1 (en) * 2004-02-18 2005-09-15 Ruben Reich Exhaust silencer for motor vehicles, contains series of truncated cone shaped partition walls
US20070227810A1 (en) * 2006-03-29 2007-10-04 Yamaha Hatsudoki Kabushiki Kaisha Vehicle exhaust system
US20080000718A1 (en) * 2006-05-30 2008-01-03 Honda Motor Co., Ltd. Muffler structure
US20120118408A1 (en) * 2009-06-22 2012-05-17 Airbus Operations Gmbh Flow limiter and use of a flow limiter in an air distribution system of an air conditioning system of an aircraft
US9587536B2 (en) 2015-04-27 2017-03-07 Charles C. Belt Exhaust muffler
US10753699B2 (en) * 2018-10-08 2020-08-25 Ut-Battelle, Llc Flow through suppressor with enhanced flow dynamics

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1140578A (en) * 1909-02-23 1915-05-25 Joseph C Coulombe Noiseless gun.
GB160334A (en) * 1920-01-24 1921-03-24 Dick Read Improvements in exhaust silencers for internal combustion engines
GB229509A (en) * 1924-03-14 1925-02-26 George Francis Power Improvements in or relating to exhaust silencers for internal combustion engines
US1953123A (en) * 1932-08-31 1934-04-03 Oldberg Mfg Company Muffler
US1991014A (en) * 1931-10-14 1935-02-12 John J Compo Muffler
US2075316A (en) * 1933-11-21 1937-03-30 Carl Theodor Setterberg Silencer for internal combustion engines
US2088576A (en) * 1936-07-24 1937-08-03 Robert W Compo Muffler
US2263407A (en) * 1940-11-28 1941-11-18 Sr Julius C Kittell Muffler for monoxide gas elimination

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1140578A (en) * 1909-02-23 1915-05-25 Joseph C Coulombe Noiseless gun.
GB160334A (en) * 1920-01-24 1921-03-24 Dick Read Improvements in exhaust silencers for internal combustion engines
GB229509A (en) * 1924-03-14 1925-02-26 George Francis Power Improvements in or relating to exhaust silencers for internal combustion engines
US1991014A (en) * 1931-10-14 1935-02-12 John J Compo Muffler
US1953123A (en) * 1932-08-31 1934-04-03 Oldberg Mfg Company Muffler
US2075316A (en) * 1933-11-21 1937-03-30 Carl Theodor Setterberg Silencer for internal combustion engines
US2088576A (en) * 1936-07-24 1937-08-03 Robert W Compo Muffler
US2263407A (en) * 1940-11-28 1941-11-18 Sr Julius C Kittell Muffler for monoxide gas elimination

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4186819A (en) * 1978-09-28 1980-02-05 Deere & Company Exhaust system for a two-stroke engine
US4595073A (en) * 1984-05-14 1986-06-17 Nelson Industries Inc. Plug-type muffler section
DE102004007756A1 (en) * 2004-02-18 2005-09-15 Ruben Reich Exhaust silencer for motor vehicles, contains series of truncated cone shaped partition walls
US20070227810A1 (en) * 2006-03-29 2007-10-04 Yamaha Hatsudoki Kabushiki Kaisha Vehicle exhaust system
US7766123B2 (en) * 2006-03-29 2010-08-03 Yamaha Hatsudoki Kabushiki Kaisha Vehicle exhaust system
US20080000718A1 (en) * 2006-05-30 2008-01-03 Honda Motor Co., Ltd. Muffler structure
US7735602B2 (en) * 2006-05-30 2010-06-15 Honda Motor Co., Ltd. Muffler structure
US20120118408A1 (en) * 2009-06-22 2012-05-17 Airbus Operations Gmbh Flow limiter and use of a flow limiter in an air distribution system of an air conditioning system of an aircraft
US9243735B2 (en) * 2009-06-22 2016-01-26 Airbus Operations Gmbh Flow limiter and use of a flow limiter in an air distribution system of an air conditioning system of an aircraft
US9587536B2 (en) 2015-04-27 2017-03-07 Charles C. Belt Exhaust muffler
US10753699B2 (en) * 2018-10-08 2020-08-25 Ut-Battelle, Llc Flow through suppressor with enhanced flow dynamics

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