US2068686A - Apparatus for silencing the exhaust of internal combustion engines - Google Patents

Description

Jan. 26, 1937. J. LASCROUX APPARATUS FOR SILENGING THE EXHAUST OF INTERNAL COMBUSTION ENGINES Filed 001;. 26. 1935 i 1 2 do m u ww R0 9 OR E TC N A T W Fl 4: JOSEPH LOU I 5 Patented Jan. 26, 1937 PATENT OFFICE APPARATUS FOR SILE N CIN G THE EXHAUST OF INTERNAL COMBUSTION ENGINES Joseph Louis Lascroux, Marseille, France Application ctober'26, 1935, Serial No.

In France November 27, 1934 4 Claims.

This invention relates to apparatus for silencing the exhaust of internal combustion engines. It is generally known that the exhaust gases leaving the cylinders of an internal combustion engine are still under such pressure that their expansion into the atmosphere produces the disagreeable noise with which everybody is acquainted.

In land vehicles driven by internal combustion engines of relatively low power, it has been found possible by means of exhaust boxes to expand sufiiciently these burnt gases to the point of obviating the noise of the exhaust, but the same is not the case with engines of much greater power, including those used in aviation. It is also commonly known that the escape of the gases from an aeroplane reveals its presonce by its noise, although the aeroplane is not visible. This noise is extremely disagreeable to the passengers, who must bear it during the whole of the journey, whereby any conversation between them is rendered practically impossible.

It will thus be realized that the expansion of the burnt gases upon leaving the exhaust pipe is one of the serious drawbacks of mechanical aerial locomotion. I

A solution of the problem set out, i. e. the suppression of the exhaust noise', is afforded by the subject of the present invention, which resides in a cellular apparatus for the silent discharge of the gases leaving internal combustion engines.

The invention has for one object to obviate completely the noise caused by' the escape of the burnt gases owing to their expansion into the atmosphere, use being made of very simple means for obtaining a free and silent escape in all internal combustion engines.

The invention has for a further object to provide apparatus for silencing the exhaust of external combustion engines and for like purposes, comprising an expansion chamber adapted to be inserted between the ends of a gap in the pipe through which the exhaust gases flow, a first group of compartments formed in the inlet end of said chamber and opening into the interior of the same, means for connecting all of said compartments with the end of said pipe connected with the inlet to the expansion chamher, a second group of compartments formed in outlet end of said chamber and opening into the interior of the same, and means for connecting all of the compartments of said sec-- (and group with the end of said pipe connected with the outlet end of the expansion chamber.

#Other objects will become apparent from the description of the annexed drawing, which now follows, and from the appended claims.

The drawing shows, by way of example only, one of the forms of the subject of the'inventlon, and

Figure 1 shows a frontview and a side view respectively of a blade grouped with other identical blades and thereby constituting the cells or compartments.

view, the interior arrangement of the cellular apparatus for the silent discharge of the burnt gases leaving an internal combustion engine.

Figure 3 is the exterior view thereof.

Figure 4 shows, in perspective, the same apparatus as is illustrated in Figure 2, a portion of the jacket being removed; this figure is given to assist in understanding the functioning of the apparatus.

This apparatus is based on the principle of the division of the currents of gas and their expansion, which is obtained without any form of baflles. It is constituted by semi-circular blades 2 (Figure 1) having an aperture 3 of the same shape. These blades are judiciously grouped, in numbers varying according to the power of the engine, inside a jacket 4 ,(Figure 2) etc., preferably of cylindrical shape; Each group of blades is in communication through its aperture 3 with a. somewhat spoon-shaped portion of tube 5, which is integral with the inlet pipe 6 for the burnt gases.

Atthe rear of the first group of blades 2, is situated an expansion chamber 1, the volume of which is also proportional to the power of the engine. Following this chamber is situated another group of blades 2, the apertures 3 of which are also in communication with the portion of tube 8, the form of which is identical with that of and which is integral with the pipe 9 for the discharge into the atmosphere of the completely' expanded burnt gases. Each group of blades forms an expansion stage, these stages being more or less numerous according to the volume of the gases to be expanded and therefore not being limitative.

When constituted in this manner, this apparatus functions as follows:

The burnt gases arrive in the apparatus through the pipe 6, and on reaching the cupolashaped apertures and the edges of the blades 2 forming an equal number of cells, they become divided by penetrating into the latter in the direction of the arrows l0 (Figures 1, 2 and 4) and leave each of these cells forming expansion Figure 2 illustrates, in a longitudinal sectional 1o

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