US1924605A - Muffler - Google Patents

Description

Aug. 29, 1933.v L, L. HAAs Er AL MUFFLER Filed Ooi. '7, 1930 Patented Aug. 29, 1933 UNITED sTATEs PATENT OFFICE MUFFLER poration of New York Application October 7, 1930. Serial No. 486,937

7 Claims.

This invention relates to improvements in mufilers of the kind commonly employed in connection with internal combustion engines for reducing the noises caused by the exhaust of the engines.

The objects of this invention are to provide a muffler of improved and simpliiied construction, in which a straight, uninterrupted passage through the muler is provided, and in which bailles or deilectors are provided which cause portions of the gases to impinge upon other portions of the gases to reduce the noises of the exhaust; also to provide a muler in which bailles are employed, which are arranged to operate by an ejector action to cause a portion of the gases flowing through one part of a baille to induce a flow of another portion of the gases through another part of the baiile, and then mixing these two portions of the gases, thus breaking up the sound Waves to produce a silencing effect; also to provide bailles of this type With deflectors of improved construction which assist in guiding the two portions of the gases into contact; also to provide a muiller of this kind, in which a baille may have other parts secured thereto to form a unit, which in turn is secured to the shell of the muffler; also to improve the construction of muiilers in other respects hereinafter specified. v

In the accompanying drawing:

Fig. l is acentral longitudinal section of a muler embodying this invention;

' Fig. 2 is a transverse sectional elevation thereof, on line 2 2, Fig. 1.

In the muiller illustrated in the drawing, and which constitutesone embodiment of our invention, A represents the outer cylindrical shell of the muiiler which is provided at one end with a head B suitably secured to the shell and having a short cylindrical projection b, which may be connected with the exhaust pipe of an engine and through which the gases enter the muiller. At the other end of the shell a discharge head C is provided, secured at its outer portion to the shell, 45 and having a tubular projection c, which may be connected to a tail or discharge pipe (not shown),

or .through which the gases may be discharged directly to the atmosphere. All of these parts,

which constitute the housing of the muiller, may

,-0 be of any suitable or desired construction and of themselves form no part of'this invention.

D represents bailles embodying this invention, three of these bales being shown in the construction illustrated,v but it will be obvious that any desired number may be employed in a muffler to produce the desired muilling effect. Each of these bailles is preferably provided with an outer flange 5, which may be welded or otherwise secured to f the inner surface of the shell A of the muffler. 60 The baille isof substantially funnel shape, tapering more or less irregularly in the direction of the flow of gases through the muffler. The baille has a substantially central discharge opening or orillce 6 therein, which is preferably in the form of a short tube formed integral with the baille. The portion of the baille between the outer ange 5 and the discharge passage 6 may be more or less tapered or stepped toward the direction of flow of the gases, an intermediate inclined portion 7, in the particular construction shown, being provided with a series of apertures or openings 8 therein, through which some of the gases passing through the mulller may flow. By means of this construction, there is a tendency of gases to iiow both through the orifice 6 and through the several apertures 8 arranged about this central opening. The flow of gases through the aperture 6 has an ejector action, forming a partial vacuum at the side of the baffle facing the discharge end of the muiiler. This action of the gases passing through the central aperture 6 induces a flow of gases through the apertures 8 in addition to the amount of ilow that would pass through these openings without the ejector`action. The gases passing through these apertures are then mixed with the gases which have passed through the opening 6. This mixing of the gases resulting from the ejector action, together with the impinging of the gases discharged through the openings 8 against the jet of gas from the orice 6, produces an effective reduction of the noises of the exhaust by breaking up of sound waves.

At the left hand side of Fig. 1, a second baille E is provided which is similar in construction to the baille D, except that the baille E is provided at its outer edge portion with a tubularv extension 10 which makes it possible to secure this baiile to a cylindrical portion or shoulder 9 of the baille D adjacent to the flange 5 but of lesser diameter than the flange 5. This baille E, acting on the gases in a manner similar to the baille D and in conjunction with the baffle D, produces a greater silencing effect than the baffle D alone. By means of the construction described, the baffle E can be welded or otherwise secured to the baille D before the baille D is secured to the shell A, thus facilitating the assembling of the two baffles in the muiller.

If desired, the ejector action of the baffles may be supplemented by providing means for guiding gases discharged through the openings 8 in the bailles toward the jet of gas discharged through the orice 6. Any desired construction may be employed for this purpose, that illustrated in the drawing including a deilector F, which may be used in connection with the bailles D or E as shown in Fig. 1. This deflector is substantially bell or funnel shaped, the edges thereof being secured to the shoulder 9 of the baille D, or if a deflector of this type is to be used in connection with the baille E, it may, if desired, be secured to a shoulder 11 formed on the baille E, as illustrated at the left of Fig. 1. The deflector F is provided with a discharge passage or opening 12 which is preferably of somewhat greater diameter than the discharge passage 6 in the baille D, or of the discharge passage 10a in the baille E. The concave curved or bellshaped portion 14 of the deflector is so shaped as to guide any gases discharged through the apertures 8 in the baille D, or through the corresponding apertures in the bailleE, toward the axis of the muiiler. Thus, the deflector F ensures a positive movement of the gases discharged through the apertures 8 toward the axis of the jet of gas discharged through the orifice of the adjacent baille, and thus causes them to impinge against gases discharged through the passage 6 and also assists in causing a mixing of the gases, thus adding ma terially to the silencing effect produced by the baille alone.

In the muiller illustrated, three different arrangements of bailles are illustrated, and muillers may be built using any one of the three arrangements shown, or using any combinations of. these arrangements. The deflectors F have been found very desirable and of great value in helping to silence noises of the exhaust, but it will be understood that it is not necessary to use these deflectors, since satisfactory muilling effects can under certain conditions be produced by merely using baffles alone. Different arrangements of the bailles, and deflectors shown, and any desired number of baffles and deflectors per muiller may also be employed in constructing muillers for different sizesof engines to produce the desired silencing eilect on different volumes of gases discharged by different engines.

By spacing the bailles or bailling units at distances from each other in the shell of the muffler, expansion chambers are formed between the baffles or units in Which lthe gases are permitted to expand. This alternate arrangement of baflles and expansion chambers `also assists in'silencing noises.

The muiller described is thoroughly effective in operation of sturdy construction, and is also easily manufactured.` The baflles and deflectors can be formed by stamping operations and the assembling of the bailles and deflectors into units can be easily done by spot welding or other means, before the units are assembled in a shell, and consequently, the correct positioning of the parts of the units relatively to each other is greatly facilitated. The units or individual bailles, if such are used, can then be very easily secured by welding or otherwise in the single shell of the muiller.

We claim as our invention:

1. A muffler having a housing provided with inlet and discharge openings, a baille arranged in said housing and having a discharge orifice approximately equal in size to the discharge opening in said housing and openings of smaller size arranged about said oriiice, and a deflector arranged within said housing beyond said baffle and `having an opening in alinement with said oriflee and imperforate walls formed to guide gases flowing through said openings in said baille tovarranged about said orifice, and a deflector mounted on said baille and having a discharge opening larger than said orifice and in alinement therewith and having an imperforate Wall for guiding gas discharged from said openings of said baille toward the jet of gas passing through said orifice.

3. A muiller having a housing provided with inlet and discharge openings, a baille arranged in said said housing and having a discharge orifice approximately equal in size to the discharge opening in said housing and openings of smaller size arranged about said orifice, and a deilector secured on said baille having a concave portion formed to guide gas discharged from said openings toward the jet of gas discharged through said orifice and having an opening in alinement with said orifice of said baille, said deflector being otherwise imperforate.

4. A muiller including a substantially cylindrical housing, a substantially funnel-shaped baille secured to said housing within the same and which tapers in the direction of flow of the gases through said muiller, and which has an orifice in the smaller end thereof and openings arranged about said orifice, and a deflector supported entirely from said baille and having a curved portion which guides gases discharged through said openings radially toward the jet of gas discharged through said orifice.

5. A muiller having an outer shell and having inlet and discharge openings, a substantially funnel-shaped baille arranged within said shell and tapering in the direction of flow of gases through said muffler, the outer portion of.said baille being secured to the shell of the muiiler, said baille having a discharge orifice in the smaller end thereof approximately equal to the discharge opening of the muiller, and openings of smaller size arranged about said orifice, and a`deflector supported entirely on said baille and having walls which curve inwardly toward the axis of the orifice of said baille to guide gases discharged through said openings towards the sides of the jet of gas discharged through said orifice.

6. A mufller having an outer shell, a baille arranged in `said shell and having a flanged peripheral portion secured to said shell, said baille tapering in the direction of flow of gases through the muffler 'and being provided with a substantially central discharge orifice, a substantially cylindrical shoulder portion formed on said baille and of less diameter than said flange, and discharge openings in said baille arranged between said orifice and said shoulder, and gas deflecting means secured to said shoulder for deflecting gas discharged through said openings toward the jet of gas discharged through said orifice.

7. A muffler having an outer shell, a baille arranged in said shell and having a flanged peripheral portion secured to said shell, said baille tapering in the direction of flow of gases through the muiller and being provided with a substantially central discharge orifice, a substantially cylindrical shoulder portion formed on said baille and of less diameter than said flange, and discharge openings in said baille arranged between said orifice and said shoulder, and a substantially bell-shaped defiector having a central opening and having its portion of greatest diameter secured to said shoulder for deflecting gases discharged through said openings toward the :let of gas discharged through said orifice.

LUCIEN L. HAAS. GAIL C. STARKWEA'IHER.A

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