US2716463A - Muffler - Google Patents

Description

1955 E. D. LATULIPPE MUFFLER 2 Sheets-Sheet 1 Filed Sept. 27. 1954 R w 0 L T U m T A V N D Y D v E N OOOOOO0OOOOO0000000000000QOOOOOOOQOOOOOOOQ OOOOOO OOOQ OOOOOOOOOOOOOOOOOOOOOOOQOQOO00000000000 000000 OOOOOOOOOOOOOOO000000000 000000 000000 00 0 C 0000 0000.0000000000 0 0 0000000000 o o ov o n u nv E 31 9% 5 mm 3 ow mm ATTORNEY Aug. 30, 1955 E. D. LATULIPPE 2,716,463

MUFFLER Filed Sept. 27, 1954 2 Sheets-Sheet 2 EDDY D. LATULiPPE INVENTOR ATTORNEY United States Patent MUFFLER Eddy D. Latulippe, Englewootl, N. J., assignor to Turbosonics, Inc., Newark, N. J.

Application September 27, 1954, Serial No. 458,497

11 Claims. (Cl. 181-55) This invention relates to a muffler for airplane or other high powered internal combustion engines. The invention has particular reference to an adjustable muffler which may be set in one position for starting and take-off conditions and then set at another position while cruising. Adjusting the muffler in this manner changes the back pressure and permits full utilization of the engine power when starting.

Many types of mufflers have been designed for internal combustion engines and some are very effective when used with low power engines such as are used by automobiles. Other types have been used for more powerful engines but in order to reduce the noise of the exhaust to an unobjectionable value, heavy components were required and mufllers of this type have been quite bulky. The present invention comprises a light weight mufiler having a long cylindrical shape which is readily adaptable for use-on airplanes since it offers little wind resistance. It comprises several acoustical traps which absorb the sounds of the motor exhaust and permit only a small percentage of the noise to be radiated.

One of the objects of this invention is to provide an improved adjustable muffler which avoids one or more of the disadvantages and limitations of prior art mufflers.

Another object of the invention is to reduce both the size and weight of mufflers while at the same time increasing their sound deadening efliciency.

Another object of the invention is to provide an ad justable means in the mufiler so that the full power of the engine may be realized during starting and take-oii conditions and then set at a second position for cruising.

One feature of the invention includes a sound trap comprising an outer cylindrical wall which has no perforations in conjunction with an inner conical metallic partition having circular perforations in spaced relation for a part of the partition surface. The cylindrical wall and the conical partition are welded together and form a sound trap which dissipates sound energy passing through the mufiler.

A second feature of the invention includes an adjustable perforated metallic cone which may be placed in first position which requires all the exhaust gases to pass through its perforations before emerging into the atmosphere. When the metallic cone is placed in a second position the exhaust gases are permitted to bypass the perforations in the cone and escape into the atmosphere by a more direct route. In this latter condition the muffler produces substantially no back pressure.

For a better understanding of the present invention, together with other and further objects thereof, reference is made to the following description taken in connection with the accompanying drawings.

Fig. 1 is a side view of the muffler.

Fig. 2 is a cross sectional view of the muffler taken along its vertical axis.

Fig. 3 is a front view of the muffier showing the end which is attached to the exhaust manifold of the engine.

Fig. 4 is a view of the rear end of the muflier.

Fig. 5 is a cross sectional view taken along line 5-5 contains no perforations.

of Fig. l and shows a portion of the adjustable mechanism used to position the adjustable cone inside the mufller.

Fig. 6 is a side view of a portion of the mufiler similar to Fig. l but with portions cut away in order to show part of the adjusting mechanism.

Fig. 7 is a cross sectional view of the mufller taken along line 7-7 of Fig. 2 and shows the means for retaining the perforated cone in axial relationship with the outer housing.

Fig. 8 is a cross sectional view taken along line 88 of Fig. 2 and shows a second means for retaining the perforated cone in its proper position.

Fig. 9 is a cross sectional view of the mufiler taken along line 99 of Fig. 2.

Fig. 10 is a cross sectional drawing similar to Fig. 2 but showing only a part of the mufller and in a position where the adjustable cone has been moved forward to permit the exhaust gases to by-pass the cone perforations.

Referring now to the drawings the mufiler comprises a main cylindrical housing which may be made of any durable metal such as stainless steel. At the front end of the muffler a junction flange 21 is positioned having a section of a spherical outer surface which may be joined to the exhaust manifold of an airplane engine to provide a tight fitting junction. Three bolt brackets 22 are welded to the outer housing so that bolts may be employed to secure the mufiier to the manifold. At the rear end of the muffler a slightly rounded cylindrical portion 23 is secured. This portion contains a constricted section 24 which forms a gate or valve into which an adjustable portion of the muffler fits. Within the portion 23 a coneshaped baffie 25 is secured by means of four metallic plates 26. The battle 25 includes a first cone-shaped portion 27 which is aligned with the axis of the muffler and A second cone-shaped portion is welded to portion 27 and contains a plurality of small holes 30. A third portion of the baffie includes a cone-shaped metallic barrier 31 which is welded to portion 28 and extends from that portion to the rear of the muffler. A fourth portion 32 comprises a perforated plate which is mounted at right angles to the muifier axis and is welded in position as shown in the drawings.

Within the mufiler housing and axially aligned therewith is a long cone 33 containing a plurality of perforations throughout its entire length but supported by a solid end piece 34 which fits into the constricted portion 24 and also supported at its front end by a solid cone 35 which projects slightly into the exhaust manifold. This perforated bafile cone 33 is supported in A position by eight fins, four near the small end and four more near the larger rear end. These fins permit the bafile 33 to be moved along the axis of the mufiler housing and thereby alter the muffler characteristics. Four fins 36 are welded near the front end of baffie 33 (see Figs. 3 and 7) and are slidably engaged by a set of cooperating brackets 37. Brackets 37 are welded to the inside surface of another baffle 38 which functions as a sound trap and will be described later. Four fins 40 are welded to baffle 33 near its rear end in a manner similar to fins 36. These fins fit into brackets 41 which are welded to the outer housing 20 (Figs. 2, 8, and 10).

In order to absorb a large percentage of the sound energy as it enters the muffler an acoustical trap 38 is welded to the housing 20 near the front end. This trap includes a rounded portion 42 which contains no perforations, a rear portion 43 which also contains no perforations and a central portion44 which contains a plurality of perforations which are about twice as large as the perforations in cone bafile 33.

The adjustable baffle 33 may be moved from its position shown in Fig. 2 to its position shown in Fig. 10 by means of a lever mounted on a short shaft 51 and coupled to a rod 52, the other end of which is coupled to a plate 53 which is welded to baffle 33. Shaft 51 may be moved by any suitable means such as a wheel controlled by a chain or cable which leads into the pilots compartment. In Figs. 1, 5 and 6 shaft 51 is turned by a second lever 54 which contains a retaining bolt 55 which fits into any one of a number of holes 56 in a dial plate 57 which is welded to the housing 20.

When the engine is started or when an airplane is taking off from the ground full power from the engine is generally desired regardless of the attendant noise. Under these conditions the baffle cone 33 is moved to the front of the muffler opening a space between constricted portion 24 and the solid end portion 34 of the bafile. This permits the exhaust gases to pass through the muffler and into the atmosphere with substantially no back pressure thereby permitting the engine to develop its maximum horsepower, however, even under these conditions a large portion of the exhaust noise is eliminated since the sound trap formed by baffle 38 eliminates a large percentage and bafiie 25 at the exhaust end of the muffler also reflects a considerable portion of the sound energy.

When the airplane has attained cruising height and its engines are throttled down to cruising speed the conical bafile 33 is moved to the rear until portion 34 fits into constriction 24, thereby forcing all the exhaust gases to pass through the perforations in cone 33 before passing into the atmosphere. With the muffler adjusted to this position all of the objectionable noise from the exhaust is trapped within the mufiler while the exhaust gases are permitted to move out into the atmosphere without creating an undesired back pressure.

While there has been described and illustrated a particular form of mufiier it will be understood that many changes and modifications may be made in the mufller design. Several additional sound traps may be added to the mufiier and an additional cone bafile may be installed without affecting the spirit of the invention which should be limited only by the scope of the appended claims.

I claim:

1. An adjustable mufller for internal combustion engines comprising, an elongated housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing and comprising a spaced metal partition having a plurality of perforations, a perforated metal cone in axial alignment with said housing and adjustably movable in a direction parallel to the housing axis, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form an adjustable gate, and a conical baffle mounted adjacent to the outlet port in axial alignment with said housing.

2. An adjustable muflier for internal combustion engines comprising, an elongated housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing and comprising a spaced metal partition having a plurality of perforations, a perforated metal cone in axial alignment with said housing and adjustably movable in a direction parallel to the housing axis, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form an adjustable gate, the apex of said cone positioned at the inlet port, and a conical baflle mounted adjacent to the outlet port in axial alignment with said housing.

3. An adjustable mufi ler for internal combustion engines comprising, an elongated gas-tight housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing adjacent to the inlet port and comprising a spaced metal partition having a plurality of perforations, a perforated metal cone baffle in axial alignment with said housing and adjustably movable in a 4 direction parallel to the housing axis, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form an adjustable gate, and a metal baffle having conical surfaces mounted adjacent to the outlet port in axial alignment with said housing.

4. An adjustable mufiier for internal combustion engines comprising, an elongated gas-tight housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing adjacent to the inlet port and comprising a metal spaced partition having a plurality of perforations in one area thereof, said area lying adjacent to the inlet port, a perforated metal cone baffle in axial alignment with said housing and adjustably movable in a direction parallel to the housing axis, the apex of said cone positioned at the inlet port, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form an adjustable gate, and a metal baflle having conical surfaces mounted adjacent to the outlet port in axial alignment with the housing.

5. An adjustable muffler for internal combustion engines comprising, an elongated gas-tight housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing adjacent to the inlet port and comprising a metal spaced partition having a plurality of perforations in one area thereof, said area lying adjacent to the inlet port, a metal cone baffle having a pluralit of n'nttually spaced perforations distributed over its surface and having an open base, said cone baflie adjustably mounted in axial alignment with the housing and movable in a direction parallel to the housing axis, the apex of said cone positioned at the inlet port, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form an adjustable gate, and a metal bafile having conical surfaces mounted adjacent to the outlet port in axial alignment with the housing.

6. An adjustable muffler as set forth in claim 5 wherein the apex of said metal cone baffle is capped with a solid metalic end piece.

7. An adjustable muffler as set forth in claim 6 wherein the metal baffie mounted adjacent to the outlet port contains a plurality of mutually spaced perforations in part of its surface.

8. An adjustable muffler as set forth in claim 7 wherein the metal baffle mounted adjacent to the outlet port contains a perforated plate mounted at right angles to the axis housing and secured to the metal baflle structure at its largest diameter.

9. An adjustable muffler for internal combustion engines comprising, an elongated housing having inlet and outlet ports and arranged to conduct exhaust gases therethrough, an acoustical trap mounted on the inside surface of said housing and compriisng a spaced metal partition having a plurality of perforations, a perforated metal cone bafiie mounted in axial alignment with said housing and adjustably movable in a direction parallel to the housing axis, said cone terminating at its base in a solid ring which fits into a constricted portion of said housing to form a gate, manual control means for moving said cone toward the inlet port to open said gate and permit exhaust gases to pass therethrough.

10. An adjustable rnufiler as set forth in claim 9 wherein said manual control means includes a lever mounted exterior to the housing, a stub shaft rotatably mounted in the housing, and a mechanical coupling between the stub shaft and a portion of said metal cone bafiie.

11. An adjustable rnufiier as set forth in claim 10 wherein said manual control means includes a mechanical coupling for moving the metal cone bafile toward the outlet port to close said gate and require the exhaust gases to pass through the cone baflie perforations before passing g H through the outlet port.

No references cited.

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