US 3111191 A
Description (OCR text may contain errors)
Nov. 19, 1963 J. BACHERT 3,111,191
. MUFFLER DEVICE 2 Sheets-Sheet 1 llllllllll ll||| l; illlwhim-m IIIIIIIIIIIIIIMM" [Ill "III i inw II .kill
III!! lill ily "mum Wimum lnluplfu llwl /6-2 6- F F 3 INVENTOR Hmm/, may" J. BACHERT MUFFLER DEVICE Nov. 19, 1963 -Sheet 2 Filed Jan. 15, 1962 A Wlmmm @Wilmlmmmm A mmmmhwfmumlmm INVENTOR United States Patent O 3,111,191 MUFFLER DEVICE John Bachert, 2204 Cortez Lane, Sacramento, Calif. Filed Jan. 15, 1962, Ser. No. 166,113 3 Claims. (Cl. 181-56) The device relates to sound-reducing structures and, more particularly, to devices adapted to reduce the noise caused by hot gases exhausting from an engine.
While innumerable types of muillers have been in use for many years, the prior devices have balanced the opposing factors of high noise reduction and low back pressure with but a moderate degree of success.
It is therefore an object of the invention to provide a muiller device which accomplishes a high degree of sound attenuation without a correspondingly high increase in back pressure.
It is another object of the invention to provide a muffler which reduces substantially the noise level of engine exhausts, yet which occupies but a relatively small amount of space.
It is yet another object of the invention to provide a muffler device which is efficient, long-lived and relatively economical to manufacture.
It is a further object of the invention to provide a muiller which is suitable for a great variety of engine types.
It is another object of the invention to provide a generally improved muiller device.
Other objects, together with the foregoing, are attained in the embodiment described in the following description and shown in the accompanying drawings in which:
FIGURE 1 is a median vertical longitudinal section, a portion being broken away to reduce the extent of the ligure;
FIGURE 2 is a front elevational view of one of the baille elements, the plane of the View being indicated by the line 2-2 in FIGURE 1;
FIGURE 3 is a front elevational view of the baille element immediately succeeding the form of baille element shown in FIGURE 2, the plane of the view being indicated by the line 3 3 in FIGURE 1; and
FIGURE 4 is a perspective view of a typical array of baille elements assembled within a housing structure, the housing being shown in outline.
While the muiller of the invention is susceptible of numerous physical embodiments, depending on the Y environment and requirements of use, substantial numbers of the herein shown and described embodiment have been made, tested and used, and all have performed in an eminently satisfactory manner.
The muiller device of the invention, generally designated by the reference numeral 11, comprises an elongated housing 12 having at its front or forward end 13 an inlet port 14, or opening, through which enters a stream 16 of hot exhaust gases from, for example, an internal combustion engine, not shown. An inlet pipe 17 provides a convenient connection to the exhaust pipe 18 leading from the engine.
At the rear or after end of the housing an enclosing drum 21 is provided, the drum 21 including an exhaust conduit 22 leading to the atmosphere, or to an anti-smog device (not shown), and a forwardly extending annular ilange 23 suitably drilled and tapped to receive a fastening member 24. Under certain conditions it has been found preferable that the conduit 22 be somewhat larger in cross-section than the inlet pipe 17.
Disposed within the housing and interposed in the ilow of exhaust gases 16 so as to produce the zig-zag ilow indicated by the arrows in FIGURE 1 is a plurality of bailles, or gridworks, the array of bailles being generally des- 3,111,191 Patented Nov. 19, 1963 ignated by the numeral 31, as appears most clearly in FIGURE 4.
kIt is important to note that the size, arrangement, number and spacing of the individual grids or baille units will vary somewhat in accordance with the environment and conditions of use. In general, the greater the power of the engine being serviced, the greater the total surface area of the bailles interposed.
Operational requirements will, at times, dictate that the baille elements be placed in groups. For example, as appears in FIGURE 4, three baille units are followed, with some space between, by another baille element 31. At other times a continuous unspaced succession of baille elements, as in FIGURE 1 produces a somewhat greater eiliciency. The desired arrangement is, in any particular situation, quickly arrived at by anyone having some actual experience with the baille elements illustrated and hereinaftcr described in detail.
As clearly appears in allA of the figures, the successive baille units or elements are formed in alternatingly inclined fashion.
For example, FIGURE 2 is a front elevational view of a baille unit adapted to deilect entering exhaust gases in a left-hand and downward direction (the downward portion of the movement being illustrated in FIGURE l). This type of unit, therefore, is termed a down-left unit and is generally characterized by reference numeral 33.
FIGURE 3, on the other hand, illustrates an opposing arrangement wherein the gas ilow is deflected and directed upwardly and in a right-hand direction. This type of baille unit is termed an up-right element and is generally designated by reference numeral 36. It is to be noted that, structurally, the units 33 and 36 are identical, thus effecting economies in manufacture. Unit 36, in other words, is the same as unit 33 turned upside down and rotated through ninety degrees. f
The baille units arevfabricated so as to conform to th cross-section of the housing in which they iit with some snugness, the bailles being thereby enabled to transfer to the housing walls the heat received from the hot gases. Cooling tins, not shown, may be added to the housing exterior to augment this cooling effect, if necessary. In still other applications, in aircraft use, for example, an opening (not shown) in the forward end 13 of the housing or a forwardly facing scoop (not shown) projecting outwardly from the pipes 17 or 18 can be provided to inject a predetermined amount of cool air into the stream of hot exhaust gases.
Lengthwise, the baille units are held in place by appropriately located and dimensioned spacing members such as a forward annular spacer 41 and an after spacer 42.
The baille units each comprise a plurality of vertical wall members 46 and intersecting horizontal wall members 47, the assemblage forming a gridwork.
As appears most clearly in FIGURES 2 and 3, the verti` cal and horizontal walls are angularly displaced from a plane perpendicular to the general transverse plane of the baille itself. That is to say, and as is shown in FIGURE 2, the vertical wall 46 extends from its leading edge 51 1n a rearward and left-hand direction to terminate at its trailing edge 52. The horizontal wall extends from its leading edge 56 in a rearward and downward direction to terminate at its trailing edge 57.
In eilect, the gridwork of intersecting walls comprises a plurality skewed chambers 61, or conduits, each having a forward opening 62 andV an after opening 63 through 1 which the gases ilow.
In the down-left form of baille, shown in FIGURE 2, it is apparent that the entering gases are rst divided into a plurality of `discrete ilow channels, or ilow paths. y Then, each of the discrete gas flows is directed downwardly and toward the left.
Upon emerging from the after end of the discrete conduits 61, the gases immediately encounter the succeeding up-right form of bale shown in FIGURE 3. At this juncture, the discrete streams of gas are abruptly subjected to a change in direction and are caused to travel in an upward and a right-hand direction.
At this point it is carefully to be noted that the dimensions and angles of inclination, or slope, of the walls is selected so that when the down-left baies 33 and the up-right bafiles 36 are juxtaposed, as in FIGURES l and 4, the discrete gas streams emerging from the after opening 63 in the baille '33 are split into four equal parts as they enter the forward opening 62a in the succeeding baffle 36. In other words, each intersection of the leading edges 56a and 51a of the horizontal and vertical walls, respectively, of the baie 36, is located in the center of the after opening 63 of the baffle 33, this bi-section feature being clearly shown in FIGURE l.
Thus, the individual gas streams emerging from the baille 33 are divided into four parts and each of these four streams is thereupon subjected immediately to a change in direction. l
In like manner, gases emerging from the conduits of the baffle 36 are caused to split intofour equal parts as they enter the following baffle, which is of the down-left variety 33, shown in FIGURE 2.
As will be realized, the successive splitting of the streams of gas and their change in direction is also accompanied by re-combining streams of gas since portions of the after openings of the four conduits from one baille share one forward opening in the succeeding conduit.
The effect of this continuous process of splitting and recombin-ing into new combinations of lgas streams, together with the yalternating or zig-zaggin-g motion `of these streams is to produce a marked reduction in noise level as the lgas finally emerges from` the outlet pipe 22; yet this is accomplished without causing any signicant increase in back pressure.
It is t-heorzed that the complex flow pattern of the gas as it passes through the device quickly causes the gas to give up its energy to the bales and to the housing walls, loss of energy through expansion also appearing to be a factor. At the same time, however, build-up of backpressure is held to a minimum.
It can therefore be seen that I have provided a muflier device which is uniquely capable of balancing the factors of noise attenuation and back-pressure in a highly effective manner.
What is claimed is:
1. A muflier device comprising:
(a) an enlongated housing having at one end an inlet port and at the other end an outlet port;
(b) a first set of baflles disposed in said housing in longitudinally spaced relation, each of said baffles including a plurality of vertical walls each extending from a vertical leading edge in a rearward and left-hand direction to terminate in a vertical trailing edge laterally displaced in a left-hand direction from said vertical leading edge, each of said baffles of said first set also including a plurality of horizontal walls intersecting said vertical walls, each of said horizontal walls extending from a horizontal leading edge in a rearward and downward direction to terminate in a horizontal trailing edge downwardly displaced from said horizontal leading edge; and
(c) a second set of bales disposed in said housing in longitudinally spaced relation and in alternating relationship with respect to said first set of baffles, each of said second set of baffles including a plurality of vertical walls each extending from a vertical leading edge in a rearward and right-hand direction to terminate in a vertical trailing edge laterally displaced in a right-hand direction from `said vertical leading edge, each of said baffles of said second set also including a plurality of horizontal walls intersecting said vertical walls, each of said horizontal walls extending from a horizontal leading edge in a rearward and upward direction to terminate in a horizontal trailing edge upwardly displaced from said horizontal leading edge.
2. The device of claim l wherein said baffles are disposed with the trailing edges of one set of baffles in close juxtaposition to the leadingedges of the following set of baffles.
3. The device of claim 2 wherein the intersections of said trailing edges of said vertical walls and said horizontal walls of said one set of baffles are located equidistantly from the four adjacent intersections of said leading edges of said vertical walls and said horizontal walls of said following set of baclcs.
References Cited in the file of this patent UNITED STATES PATENTS 1,897,649 Good Feb. 14, 1933 FOREIGN PATENTS 202,013 Great Britain Aug. 8, 1923 435,423 Great Britain Sept. 20, 1935 470,904 Italy Apr. 29, 1952 949,428 Germany Sept. 20, 1956