US 3593819 A
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Description (OCR text may contain errors)
Umted States Patent 1 1 3,593,819
 lnvcnlor AndreGiraudeau 2,114,710 4/1938 Holcomb 181/3301) Montmorencylvald'oisel,Fra e 2,541,868 2/1951 Gordon 181/33(.1) 2| ApplNo 771,742 2,809,145 10/1957 MCDrmOl1..... 181/33( 1) 22 Filed Oct-30,1968 2,850,110 9/1958 Benjamin..,.. 181/33(.1) 4s Palenlfid Ju1 20,1971 3,026,224 3/1962 ROgCrS..... 181/33(.1)  Assignec LeslsolanlsFran ais 3,087,565 4/1963 Kcrwin.. 181/33(.1) sou elecenelons rthe,France 3,087,577 4/1963 P168116. 181/33(.1) apartinterestto 3,113,634 12/1963 Watters 181/50x 32 Priority Nov.7,l967 3,232,371 2/1966 12616116116161. 181/33(.1) [331 5% FOREIGN PATENTS 889,245 9/1943 France l81/33(.1) 1,064,968 12/1953 France 181/33 .1 54 ACOUSTICSOUND-A'I'IENUATINGPANELS 5 3,6 8/ y... 181/3361) 1 2Claims,6DrawingFigs. 1,154,923 9/1963 Germany 181/33 (.1)
12 77 11948 8 d 18133 .1 152 mu 181/33 we  Int. Cl E04b 1/86 P mary ExaminerRoben S. Ward, .lr.  Field of Search 181/33, lwrney'Arn0ld Robinson Y 33. I 33.1 1 j  References Cited I UNITED STATES PATE T ABSTRACT: A sound-attenuating panel includes a base and 1,948,327 2/1934 Berwick l81/33(.1
at least one set of upstanding parallel fins. Another set of fins 2,087,248 7/1937 Fischer 181/33 (.1 extend perpendicularly to the one set.
AcousticsouNn ArrrzNuA'riNo PANELS BACKGROUND OF THE INVENTION SUMMARY OF THE INVENTION The panel according to the invention is characterized in that it comprises a base provided with fins which are perpendicular to it, the whole being made of an elastomer material.
The fins may be orientated in one direction only but they are, preferably, disposed in two different directions.
- I These fins may be continuous or may be interrupted.
BRIEF DESCRIPTION OF THE DRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTS n the embodiment of FIGS. 1 and 2, the sound-attenuating panel is constituted by a plane base I which is fixed on to wall 5, and by a plurality of parallel fins 2. The latter have their planes perpendicular to that of the base I and are integral with the latter, the assembly being made of an elastomer material and manufactured, for example, by moulding or vacuum formmg.
As it can be seen in FIG. 3, a sound wave bundle 3 which impinges upon the panel and of which the direction is inclined with respect to the plane of the base I, is reflected by this base, which partially attenuates it. A part of the bundle leaves as indicated at 3a in a direction symmetic to the incident direction with respect to a perpendicular to the base I, while another part of the bundle undergoes a second reflection on one of the fins 2 and leaves as indicated at 3b in the direction of the incident wave bundle.
If the sound wave bundle is sufficiently :inclmad in relation to the base 1 or if the fins are sufficiently high in relation to the distance which separates them, the sound bundle may undergo several reflections which give rise, in each case, to a supple mentary attenuation of the sound level. Thus, for example, in FIG. 4 there is indicated diagrammatically at 4 a sound bundle and it will be noted that the latter undergoes seven reflections before leaving the panel. If the amount of attenuation is, for
example, about 0.8 at each reflection, the sound bundle leaves the panel with an intensity which is equal to 0.21 times that of the incident bundle.
The panel according to the invention'thus ensures a substantial reduction in the sound level, while only apart of the incident bundle is reflected on itself. The bundle may undergo several reflections, thus suffering each time-an attenuation, before leaving the screen.
More precisely, if 0 denotes the inclination of the sound bundle with respect to a perpendicular to the base 1, m is the distance between two adjacent fins and p is the height of a fin,
.it can be established that the edge of the bundle meeting the It is thus to advantage if the height p is relatively large and the distance m relatively small; if the valve of m is nevertheless limited by the fact that each fin has a thickness e which is not zero and that only the surface of the panel comprised within the interior of the fins is effective, the panel having thus an efficiency equal to l2(elm).
In practice, it is preferable to select m between 3 and [6 millimeters and p between 3 20 millimeters.
The embodiment of FIGS. 1 and 2 is only effective in practice if the main direction of the propagation of the sound wave lies in a plane perpendicular to the fins, such as the plane of section IIII. In effect, if this direction is, for example, in a plane parallel to the fins, the sound bundle is subjected only to As a result, if the sound source is movable, it is to advantage to provide fins 2a orientated in a first direction and fins 2b orientated in a direction perpendicular to the first, as in the embodiment of FIG. 5. The panel is thus effective, whatever the direction of the sound source.
In the embodiment of FIG. 6, there are provided not only the fins 2a, 2b orientated in two perpendicular directions, but additionally fins 2c and 2d disposed along diagonals of the squares formed by the fins 2a, 2b. This arrangement allows for a number of reflections of the sound bundle equal to that which will be obtained with the fins 2a and 2b alone and limited one with respect to the other by a somewhat smaller distance, but with a smaller quantity of material and an improved efficiency, the active surface of the panel being larger.
Moreover, in this embodiment, the fins are interrupted, at the zone where the fins 2a, 2b, 2c and 2d must intersect in such a manner that they are more flexibleand enable a better attenuation. Moreover, the different cells defined by the fins communicating between themselves, allows for example, when the panel is vertical, for moisture which may be introduced into a cell to flow downwardly towards the base of the screen.
1. A sound-attenuating panel of elastomeric material comprising a base, a first set of parallel fins projecting perpendicularly from the base, a second set of parallel fins projecting perpendicularly from the base, said first set of fins extending transversely to said second set of fins to define therewith a plurality of cells of quadrilateral cross section and a respective further fin projecting from the base and extending diagonally across each said cell between one pair of opposed corner portions of said cell, said first and second sets of fins being inter rupted in the region of the said opposed corner portions of said cells.
2. A panel according to claim I wherein said first set of fins extends perpendicularly to said second set of fins.