GB2372761A

GB2372761A - Sound absorbing wall element

Info

Publication number: GB2372761A
Application number: GB0200920A
Authority: GB
Inventors: Wilfried Huyghe
Original assignee: Deceuninck NV
Current assignee: Deceuninck NV
Priority date: 2001-01-16
Filing date: 2002-01-16
Publication date: 2002-09-04
Anticipated expiration: 2022-01-16
Also published as: DE10201610B4; DE10201610A1; FR2824344A1; GB0200920D0; GB2372761B; FR2824344B1; BE1013919A5

Abstract

The element (1) comprises a body (2, 3), preferably including two inter-engaging parts of synthetic material, having an internal space (4) in which sound absorbing material (5) is provided, a number of passages (6, Figures 4 and 5) are located in the body such that at least one wall (8, Figure 5) of each passage moves away from an axis (7, Figure 5) of the passage in a direction of the internal space. Preferably each passage widens in a conical manner towards the internal space and the part of the passage adjacent an exterior of the body is cylindrical. A number of wall elements may be connected together to form a barrier.

Description

237276 1

Sound absorbing wall element This invention relates to a sound absorbing wall element, comprising a body, substantially made of synthetic material 5 with an internal space in which a sound absorbing material has been provided, a number of passages being provided in the body, running into the internal space.

Also a sound absorbing wall made up from such sound lo absorbing wall elements comes, of course, within the scope of this invention.

This invention relates to such sound absorbing wall elements in all possible forms and dimensions. Therefore, these wall 5 elements may be, for example, block-shaped or panel-shaped, have flat or curved external surfaces, be carried out to be applied against another wall forming construction element or to form themselves a wall or part of a wall, and be suitable to be installed inside or outside.

More particularly this invention relates to walls and wall elements, provided to be installed outside, for instance, to reduce noise pollution caused by motor traffic and/or air traffic. The sound absorbing walls for outside installation known at present, substantially consist of a hollow metal structure, the side of which directed towards the sound source is provided with perforations. A sound absorbing material, such 30 as glass wool for instance, is introduced into the hollow space. These walls, however, have quite a few disadvantages: A first disadvantage is the rather high cost of material and 35 of production, resulting from their manufacturing. Therefore the cost price of these walls is rather high.

:.. o c À i Another disadvantage of these known walls is that the hollow metal structure is extremely liable to corrosion (to oxidation among others) because of bad weather conditions.

In order to avoid this disadvantage as much as possible, 5 regular maintenance is required, causing additional costs.

If part of the wall structure is damaged (for instance because of a motor car colliding with it) several parts of the damaged part of the wall have to be removed completely, in order to be able to replace the damaged parts.

An additional disadvantage is the fact that the transport and removal of the wall elements is made difficult by the relatively high weight of the metal structure. Furthermore, these wall elements cannot be recycled.

In general it may be said therefore, that these known sound absorbing wall structures are rather expensive as far as purchasing and installing are concerned and because of the costs required for the necessary maintenance and possible 20 repairs. Furthermore the sound absorption obtained when using these structures leaves much to be desired.

From the American patent US 6 021 612 a sound absorbing wall panel is known that is suitable for installation outdoors 25 and whose functioning is based on the principle of the Helmholtz resonator. This wall panel consists of a hollow panel in which cylindrical bores are provided running into a completely enclosed hollow space functioning as a resonator.

Furthermore a sound absorbing material, such as mineral wool 30 for example, is provided in this hollow space.

This wall panel is cheaper and requires less maintenance than he abovementioned wall structure, because it comprises no metal components. Because its functioning is based on the 35 principle of the Helmholtz resonator, this wall panel has the disadvantage that the internal hollow space should be

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c c; A t O t;; rather well sealed on all sides. The hollow wall panels should be carried out as closed boxes or should afterwards be closed on all sides by means of additional parts during the installation of the wall in order to obtain a 5 sufficiently efficient effect. This necessity must be considered when shaping the elements of the wall. This leads to more complex forms and/or a greater number of parts and/or more materials used. Furthermore the sound absorption to be realized, still leaves room for improvement.

It is the object of this invention to provide for a cheap and efficient sound absorbing wall panel which may be used, both for installation indoors as outdoors, and by means of which the above-mentioned disadvantages of the known wall elements and wall structures may be remedied and by means of which therefore a better sound absorption may be obtained than with the known wall structures, and even a very good sound absorption can be obtained as the internal space in which the absorption material is contained will be open, so 20 that the principle of the Helmholtz resonator is not used or only in a limited way.

This object will be obtained with a sound absorbing wall element comprising a body substantially made of synthetic 25 material with an internal space in which a sound absorbing material is provided, the body being provided with a number of passages running into the internal space and where, according to this invention, each passage has at least one wall leading away from the centre line of the passage at a 30 sharp angle in the direction of the internal space.

With a similar wall element the sound waves, striking the inclined walls of the passages, are reflected in the direction of the internal space and the absorbing material 35 it contains. Both, sound waves originating from the outside of the wall element and possibly, after several reflections,

À À... À À. , _ striking such an inclined wall, and sound waves being reflected from the internal space and striking the inclined wall, being reflected because of this in the direction of the internal space and do no longer leave the wall panel via 5 the passages. In this way a considerably greater part (in comparison with the known sound absorbing walls) of the sound waves is imprisoned in the wall element, until these sound waves have lost their energy because of the repeated reflections inside the wall element and/or because of the lo absorption in the sound absorbing material.

With the sound absorbing walls according to the state of the art, the walls of the openings run parallel with the centre line of the opening A substantial part of the sound waves 5 striking these walls, after one or several reflections, is finally reflected back out via the passage with a proportional reduction of the efficiency of the wall panel as a result.

20 By solving this problem in an efficient manner an efficient sound absorbing wall panel is obtained, which even without applying the Helmholtz principle will enable to obtain an excellent sound absorption. Because a resonator space closed on all sides, is consequently not required to realize a very 25 good sound absorption, the wall element may be carried out in such a way that the internal space is open on one or several sides. This enables the wall element to be made in a simpler and therefore cheaper manner.

30 It should be clear that also wall elements using both the principle of this invention and the principle of the Helmholtz resonator (and therefore indeed have an entirely closed internal space) are also wall elements according to this invention. The sound absorption obtained by means of 35 similar wall elements is significantly better than by the known wall elements where only the Helmholtz principle id

-i I: a : L applied. In this description and in the claims of this patent

application the term "internal space" is therefore used both 5 in the meaning of a space entirely enclosed on all sides and in the meaning of an intermediate space not enclosed on all sides between walls or wall parts (for instance a sandwich panel) even if in one of these walls or wall parts or in both walls or wall parts passages or openings have been lo provided, and even if these passages or openings take up the greater part of the wall surface.

Finally, the wall panel according to the invention has a body substantially made of synthetic material, because of 5 which it is less heavy, cheaper, and has a better weather resistance, and is easier to maintain than the known metal structures to which reference was made in this description.

Furthermore the body may be made of a recyclable or of a recycled synthetic material, so that the wall element JO according to this invention is less polluting.

Preferably, the sound absorbing wall element according to this invention is carried out in such a way that terminal part of each passage running into the internal space is 25 enlarged in a funnel-shaped manner in the direction of the internal space.

Because of this, all walls of the passages with their inclined surface are directed towards the internal space, so 30 that the sound waves are reflected towards the internal space. Because it is rather the terminal part of the passages running into the internal space that is funnel-

shaped, this embodiment is particularly efficient to reflect the sound waves, being reflected from the internal space, 35 back into the hollow space.

i; 1: r Preferably, the terminal part of each passage running into the internal space, has a conical shape. Technically, this is rather simple to realize, for instance, by drilling these passages. When realizing a passage, the transverse dimension of which are changing all along the entire length of the passage, it is very difficult to make all passages terminate with the same transverse dimensions. If this result is not realized, lo a wall element is obtained with passages, the respective entrance openings of which, on the visible outside of the wall element, have a different aspect. For instance, when drilling a conical hole, the smallest final diameter of the hole (on the visible outside of the wall element), among 5 others, is determined by the thickness of the perforated wall. This wall thickness is not always perfectly identical in all places, so that the visible entrance of the different bores might not be the same for all bores.

20 In order to perfection the wall element also from an aesthetic point of view the terminating part of said passages terminating along the outside of the body is carried out cylindrically. Therefore, all passages terminating on the visible outside of the body end up in 25 circular openings all having perfectly the same diameter.

It is also very advantageous to carry out the body with a first and a second part which are detachable from each other and which together enclose the said internal space. The so separate parts of the body may be carried out as rather simple parts of synthetic material by means of a simple manufacturing process (for instance by extrusion). The composition of a wall element is very simple and can be carried out quickly. Putting the sound absorbing material in 35 its place opposite or in the space provided for that purpose in one of the parts and joining the parts together will

-i t. À i 5 , ,,. suffice. On damaging a wall element replacing only one element often suffices. Now, also replacing or checking the sound absorbing material can be carried out quickly.

Preferably, therefore the two parts of the body can be 5 separated or joined together by hand or with the help of simple tools.

When the first and the second part respectively extends on the one and on the other side of the sound absorbing 10 material, the wall element obtains a sandwich structure, where the absorbing material can be easily inserted between the two parts of the body, before these parts are joined together and can be also removed easily from between these two parts and be replaced.

It has been ascertained that remarkably good results in the field of sound absorption are obtained if the relation

between the surface of the passages in a flank of the body directed outwards on the one hand and the total surface of said flank is situated between 20% and 40%, and preferably 20 is about 30% on the other hand.

In an advantageous embodiment the sound absorbing wall element has a body that is provided with means to maintain the sound absorbing material in a position away from the 25 passages at an intermediate distance.

Because of this it is avoided that the absorption material is situated close to or against the mouth openings of the passages and that it might be quickly damaged or made wet or dirty via these openings.

On at least one outer wall of the body an abrasion resistant coating is provided. Preferably, this is a two component polyurethane coating containing, for instance, dispersed polyamide-11 grains. A similar coating has a good resistance 35 to damages during transport and installation, requires little or no maintenance and even allows for graffiti,

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c. a applied to it, to be easily removed.

This coating can be applied, for instance, during a co-

extrusion process during the manufacturing of the body of 5 synthetic material, or can also be provided during an additional coating treatment after manufacturing the part concerned. Preferably, the body and the sound absorbing material are lo carried out in a panel-shape.

By manufacturing at least one part of the body of cellular synthetic material, a body is obtained which stops the sound better than solid materials. This is the result of the 5 closed cel structure of the cellular synthetic material.

Up till now the covering of the known wall panels served only to protect the sound absorbing material and at the same time sound waves were let through via the passages. By 20 manufacturing a body which on its own also consists, at least partly, of a material having good sound protecting qualities, this body now gets a second function. Up till now this possibility has never been considered. This quality also is a contribution to an excellent sound absorption and 25 sound protection which may be obtained by means of the wall elements according to this invention.

Furthermore, cellular synthetic materials have the remarkably advantageous property that the material has a 30 very good resistance to the introduction of fixing means,

such as among others nails, screws etc. and that these fixing means are well fixed in the material.

Another advantage of cellular synthetic materials is, that 35 their density can freely be determined, between certain limits, during the production process. This may be the case

À À À

ú. ' during a chemical foaming process by adapting the quantity of foam forming "blend" which is added during the extrusion process. The strength (elasticity modulus) of a product depends on its density, so that the strength of a product of 5 cellular synthetic material is determinable as it were during the production process.

Another important advantage of cellular synthetic materials is that they enable the manufacturing of large products with lo a rather low weight of synthetic material with a rather low degree of purity. In a first stage of the recycling process, recycled synthetic materials still contain rather many impurities, because of which the so called box system (where a number of internal thin-walled ribs provide strength) 5 cannot be used to manufacture large products of light weight. The additional purification of these synthetic materials provides a full alternative with, as already indicated, a large number of additional advantages.

20 Preferably, recycled synthetic material is used for manufacturing the body. Preferably polyvinyl chloride (PVC) is used, whether or not recycled, or an impure mixture obtained by recycling and substantially containing PVC.

Preferably the degree of purity of the PVC is at least 95%.

The sound absorbing material can also be made of synthetic material, more particularly of recycled synthetic material.

This may be done, for instance, according to a process in which synthetic fibres or filaments are sintered. To this 30 end, recycled PVC is preferred. For this purpose, foamed synthetic materials with an open cellular structure are particularly suitable. When a wall element is made of which both body and absorbing material are made of PVC, a wall element is obtained which, as a whole, is fully recyclable.

Another object according to this invention is a sound

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absorbing wall, comprising one or several sound absorbing wall elements according to this invention, as well as a number of retaining elements to maintain these wall elements in a position for use.

Such a sound absorbing wall may comprise a number of shell elements made of synthetic material which can be attached to the retaining elements in order to cover parts of them.

Preferably, these shell elements cover the visible parts of lo I-shaped elements in order to obtain a sound absorbing wall presenting the aspect of an aesthetic, homogenous entity.

These shell elements can also be made of a cellular synthetic material, preferably of recycled PVC.

Preferably, said retaining elements are I-shaped elements, whereas each shell element is provided to enclose a flange of an I-shaped element.

JO Each retaining element can also be made substantially of synthetic material, more particularly of recycled cellular synthetic material. Such retaining elements, which do not contain any metal are particularly suitable for installation in the neighbourhood of airfields, as metal structures may

25 disturb the functioning of the radar system used on airfields. If the retaining elements are made of a cellular

synthetic material they will provide an additional sound protection, because such synthetic materials are able to stop the sound waves, better than massive materials, because 30 of their closed cel structure.

Such a sound absorbing wall the retaining elements of which substantially consist of polyvinyl chloride is preferable.

35 In a preferred embodiment, a sound absorbing wall comprises several sound absorbing wall elements, which constitute the

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9 2 0

'; , a: _ À sound absorbing wall fitting together beside and/or above one another, whereas the opposite sides of the sound absorbing wall elements are provided with a protruding rib and a groove respectively, so that when fitting together two 5 wall elements, the rib of the one wall element will be in the groove of the other.

With a similar installation the wall elements are kept in their places to constitute a common surface on the one hand, lo and on the other hand there are hardly any slots between the wall elements, so that at the same time a very soundproof wall is obtained.

In the following detailed description of a few embodiments

15 of this invention the above-mentioned characteristics and advantages of the invention will be further clarified and the additional properties and advantages will be indicated.

The intention of this description is only to clarify some

general principles of this invention and therefore, in no 20 way, they may be interpreted as a limitation of the field of

application of the invention or of the patent rights claimed in the claims.

In this description reference is made, by means of reference

25 numbers, to the subjoined figures 1 to 22 of which: - figure 1 is a side view of a sound absorbing wall element according to this invention; figure 2 is an enlarged side view of the left part of 30 the body of the wall element represented in figure 1; - figures 3 and 4 represent an enlarged side view and a front view of the right part of the body of the wall element represented in figure 1 respectively; - figure 5 is a crosssection according to the axis AA of 35 a part of the body represented in figure 4; - figure 6 is perspective drawing of an I-shaped element

À-- À. o . t À.

' i t À À with on both sides, between the flanges S-shaped insertion elements, and on the outside of each flange three different types of shell elements) - the figures 7, 8 and 9 are cross-sections of the I 5 shaped element represented in figure 6, on which each time a different type of shell element is shown) - figures 10 and 11 represent a top view of retaining elements made of synthetic material) - figures 12 and 13 represent a top view and a lo perspective drawing of another retaining element of synthetic material in conjunction with wall elements according to this invention; - figure 14 represents the dismantled parts of a part of the wall construction, showing wall elements verically 5 installed one beside the other, represented in perspective; - figures 15 and 16 represent a side view and a top view respectively of the assembled wall construction of figure 14; - figure 17 is a top view of a part of the wall 20 construction of figure 14, without the panels and the upper horizontal shaped insertion element; - figure 18 represents the dismantled parts of a part of the wall construction with the wall elements horizontally installed one beside the other, represented in perspective; 25 - figures 19 and 20 are side views of an upper part and a lower part of the assembled wall construction respectively; and - figures 21 and 22 are top views of an I-shaped element with the accompanying accessories of a wall construction 30 according to this invention.

The wall element (1) represented in figure 1 is a rectangular panel (2,3) consisting of two parts (2),(3) joined together, which at the two opposite sides enclose a 35 hollow intermediate space (4) in which a rectangular piece of sound absorbing material (5) is provided.

À. i À À.: 6 S À À

i::,, The part (2) represented in figure 2 has a rectangular flat part (21) having a length of 500 mm and a width of 90 mm. On each of the opposite long sides (the upper side and the 5 lower side) a protruding wing (22),(23) is provided in one and the same direction and over a same distance, forming a right angle with the flat wall (21), so that this part has a distinctive U-shape. In that which follows this part is called the U-shaped panel. The thickness of the material is 0 about 18 mm. This U-shaped panel is obtained by an extrusion process of recycled PVC, adding a foaming agent, so that the product has a density factor of between 0.5 kg/l and 1.2 kg/l. During the same process a thin coating is applied to the outer surface by co-extrusion. This coating is a two 5 component polyurethane coating containing dispersed grains of polyamide- 11 so that it will need hardly any maintenance to render it resistant to graffiti and give it a high abrasion resistance.

20 On the side of the wings (22),(23) three protruding ribs (26),(27),(28) are provided on the flat wall (21) of the U-

shaped panel, equidistant from one another. They are provided for the positioning of the absorbing material (see further). On the upper side of the wing (22) a U-shaped 25 groove is provided running parallel with the flat wall (21) and extending over the full length of the U-shaped panel (2). On the underside of the mower wing (23) a rib (25) is provided in a shape corresponding with the shape of the groove (24), so that the rib (25) fits into the groove (24) 30 of another wall element (l). This rib (25) equally extends over the full length of the U-shaped panel (2).

The part (3) represented in figure 3 in that which follows called the cover also comprises a flat wall (31) which on 35 each of the two long sides situated opposite one another (the top and the underside) turns into an identical slanting

c.: dL À l c. - edge (32),(33). Both edges (32), (33) are situated on the same side of the flat wall (31) and turn into respective terminal shaped elements (34),(35). These terminal shaped elements ((34),(35) are each others mirror image. The edges 5 (32),(33) and terminal shaped elements (34),(35) extend over the full length of the cover. The terminal shaped elements have two flat angle forming parts (36),(37) of which one part (36) runs parallel with the flat wall (31) and the other (37) is at right angles to this wall (31) and ends in lo a thickening (38). On the same side as the edges (32), (33) an upright rib (38) is provided on the flat wall (31), which extends in the centrally in the longitudinal direction of the cover.

15 When the parts of the body represented in the figures 2 and 3 are joined together, as represented in figure 1 the thickenings (38) of the cover (3) pointing away from each other stick to the flanks of the respective wings (22),(23) pointing towards each other of the U-shaped panel (2). In 20 this manner the two parts (22),(23) are kept together and are easily detachable by hand.

The flat walls (21),(31) of the parts (2),(3) joined together are installed opposite to and parallel with each 25 other at an inter,mediate distance and limit the internal hollow space (4) along the front and back of the wall panel (1). The wings (22),(23) of the U-shaped panel (2), the terminal shaped elements (34),(35) stuck to it and the slanting edges (32) ,(33) of the cover (3) limit this hollow 30 space (4O along the top and the bottom of the wall panel (1). The sides of the wall panel (&) are left open. In the internal space (4) there is a panel-shaped piece of sound absorbing material (5). This absorbing material is maintained in its place (see figure 1) between the three 35 ribs (26),(27),(28) of the U-shaped panel (2) on the one hand and the central upright rib (39) of the cover (3) and

À A: c - i y the terminal edges of the thickenings (38) at the top and the bottom of the cover (3). Because of this, the absorbing material (5) is maintained in the internal space (4) in the body (2),(3) at a distance from the cover (3). Because of 5 this the absorbing material (5) is kept well in its place.

Because of the rather great distance between the cover and the absorbing material (5) it will not be easily damaged via the passages (6), for instance, with malicious intent. The absorbing material is also sufficiently away from the 0 openings, so that splashing water which might enter the internal space via the passages, will not wet or soil the absorbing material.

In the flat wall (21) of the cover (3) a great number of 5 traversing bores (6) are provided (see figures 4 and 5) the axes (7) of which are directed perpendicularly to the flat wall (21). These bores (6) are divided in several rows all over the surface. Each bore (6) has a cylindrical terminal part an the outside of the cover (3) and turns into a 20 conical part enlarging in the direction of the inside of the cover (3) and ends on this inside with its maximum diameter.

On the side of the cylindrical part the conical part has its minimum diameter which is equal to the diameter of the cylindrical part. The wall of the conical part of each bore 25 (6) takes a sharp angle (a) with the axis (7) of the bore (6) and this wall moves away from the axis (7) in the direction of the inside of the cover (3).

The U-shaped panel (2) is made of recycled PVC by extrusion, 30 whereas during the production process a chemical foaming has occurred by adding a foaming agent. So the U-shaped panel (2) is made of cellular PVC.

The cover (3) is also made of recycled PVC, but here the 35 synthetic material has not been foamed in order to obtain a product with a maximum impact resistance. The cover (3)

_ f O -

c, ó . constitutes the front of a wall element (1) and is most in danger to be damaged, for instance, by stones.

When composing a sound absorbing wall use may be made of 5 metal I-shaped elements (40) to maintain the wall elements (1) in an upright position. The I-shaped elements (40) are anchored in the ground at a certain intermediate distance and the wall elements (1) are placed in a vertical position next to each other (see figure 14) or in a horizontal 0 position one above the other (see figure 15) fitting together between these Ishaped elements. The wall elements (1) being, with an edge part, in a Ushaped channel of the shaped element (40) formed between the flanges (41), (42).

5 Because the space between the flanges (41), (42) is wider than the thickness of the wall elements (1), use is made of an insertion shaped element (44) consisting of an S-shaped curved plate having the same length as the I-shaped element.

As may best be seen in the figures 6 to 9, the insertion 20 shaped element(44) is clamped between the flanges (41),(42 of the I-shaped element, a part of the space between the flanges (41),(42) being filled up and a U-shaped duct (43) is obtained with a width corresponding with the thickness of the wall elements (1). Preferable this insertion shaped 25 element (44) is made of galvanized metal.

Furthermore, the sound absorbing wall comprises also shell elements (45), (46),(47) which are made of cellular PVC by an extrusion process and which are attached to the flanges 30 (41),(42) of the I-elements (40) in order to cover them, so that a wall is obtained of which the visible parts constitute an aesthetic, homogenous whole without any inconvenient elements. To show that these wall elements may be manufactured in a very great variety of shapes, three 35 different shapes are shown in the figures 6 to 9. These shell elements (45),(46),(47) re carried out as elongated

À a : À b C; hollow tube-shaped elements with a base (48) and a curved wall fitting to this base, so that the base (48) and the said wall (49) limit the hollow space. The section of the base shows a U-shaped recess in which a flange (41),(42) of 5 an I-shaped element (40) fits. The wall (49) fitting to this base (48) determines the look of the shell element (45-47) and may be curved in a concave or a convex way or may have any other shape with Houndings and/or walls forming angles.

Because the shell elements (45-47) are made of a cellular 0 synthetic material they provide for an additional sound absorption. In a number of particular fields of application, preferably,

no metal I-elements (40) are used. For instance in the 5 neighbourhood of airfields great numbers of shaped metals

must be avoided, because they might interfere with the radar systems. For these particular fields of application shaped

materials (50),(51),(52) have been developed which are entirely made of synthetic material likewise by means of an 20 extrusion process in which a foaming agent is added to the recycled PVC.

In the figures 10 to 12 three such shaped elements are represented in cross-section. These shaped elements (50-52) have an identical central part (53), which is carried as a 25 hollow tube shape with a substantially rectangular cross-

section. On de short sides of this central part (53), situated opposite one another, terminal pieces (54) carried out in a tube shape are provided respectively which, for instance by means of glue, are attached to the central part 30 (53) to constitute the flanges of the shaped elements. These terminal pieces (54) may be carried out in a great variety of shapes, by deforming, during the production process, an originally identical tube shape in a different manner.

These shaped elements (50),(51),(52) are likewise anchored 35 in the ground in an upright position at a certain distance from each other. To be able to maintain the wall elements

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l:.: l' : -:

(1) in an upright position, holders (55) are attached to the broad side walls of the central part (53) of the shaped elements, preferably by means of glue. These holders (55) -

represented only in the figures 12 and 13 - are likewise 5 carried out as hollow shaped elements and may be glued to any place of the side walls of these central parts (53).

This is illustrated in the figures 12 and 13, where on one side of the shaped element (52) two possible positioning of the wall elements (1) are represented. This also gives the lo opportunity to compose a sound absorbing wall in such a way that not all the wall elements (1) are situated in the same plane. Therefore, the wall elements (1) may be positioned alternately between successive shaped elements (52) in a first and a second vertical plane in order to give it an 5 particularly aesthetic aspect.

In the figures 14 to 17 is shown how a wall according to this invention may be composed, by making use of I-elements (40). Between the flanges (41),(42) of two neighbouring I 20 elements anchored in a bottom plate (in figure 1, only one I-element is represented) first respective S- shaped insertion shaped elements (44) (see above) are placed to reduce the U-shaped space between the flanges (41),(42) to a less wide U-shaped channel (43) having the thickness of the 25 wall elements (1). Between the shaped elements (40) two more such insertion shaped elements are horizontally attached.

The one insertion shaped element (44) is situated near the top of the wall to be formed, the other at the bottom plate.

So, a frame-shaped structure is formed by the U-shaped so channels (43) the open sides being directed towards each another. The wall elements (1) are placed vertically in these channels (43) their closed sides one beside the other and thus constitute a row of wall elements (l)' fitting together in one vertical plane between two I-shaped elements 35 (40) situated one beside the other. This construction may be repeated between all the I-shaped elements, placed in a

Us c is 19: straight, curved or angle forming row, one beside the other to form a continuous sound absorbing wall. Of two wall elements (1) fitting together each time the rib (25) of one wall element (1) is placed in the groove (24) of the other 5 wall element (1).

The first (1) and the last wall element (1) of the row are situated between the flanges (41),(42) of a respective I-

shaped element, their edge part in the vertical channel (43) lo of the insertion shaped element (44).

Also after the upper and the lower horizontal insertion shaped elements (44) have been attached in their fixed place it should be possible to place the wall elements (1) still 5 in these channels (43) and may be still removed afterwards, for instance, to replace them without being obliged the dismantle the entire construction. therefore, the insertion shaped elements (44) are placed at a vertical intermediate distance, being greater than the length of a wall element 20 (1), so that each wall element (1) may be brought into the channels (43) of the horizontal insertion shaped elements (44) by first inserting it, its upper edge inclined, into the upper horizontal channel (43), then rotating it until it is in the vertical plane between the two insertion shaped 25 elements (44) and finally lowering it until its lower edge is in the lower horizontal channel (43). To this end the wall elements (1) however should have rather much vertical clearance. In order to avoid that because of this clearance, the wall elements (1) will be loose in the wall 30 construction, a filling shaped element (45) is shifted into the lower channel (43) (see figures 14 and 15). Because of this most of the vertical clearance is removed (compensated). 35 In the figures 19 to 22 is shown how a wall with horizontal wall elements placed one on top of the other is composed

IF 5, J e 1 À ? 1

j according to this invention, between I-shaped elements (40), vertically anchored in a bottom plate. (In figure 18 only one I-shaped element is shown). Here also, the U-shaped space between the flanges (41),(42) is limited to the 5 thickness of the wall elements (1), by means of the insertion shaped elements (44) described above. In this manner also two vertical channels (43) are obtained.

Furthermore, here also two insertion shaped elements (44) 0 are attached horizontally between the I-shaped elements. One insertion shaped element (44) is situated near the top of the wall to be formed, the other one is attached to the bottom plate. So, a frame-shaped structure is formed by the U-shaped channels (43) the open sides being directed towards each another. The wall elements (1) are placed horizontally in these channels (43) their closed sides one on top of the other and thus constituting a row of wall elements (1), fitting together in one vertical plane, each wall element extending between two I-shaped elements (40) situated one 20 beside the other. This construction may be repeated between all the Ishaped elements, placed in a straight, curved or angle forming row, one beside the other to form a continuous sound absorbing wall.

2s Of two wall elements (1) fitting together each time the rib (25) of one wall element (1) is placed in the groove (24) of the other wall element (1).

With two vertical edge zones situated opposite of each 30 other, each wall element (1) is situated in a vertical channel (43) of an insertion shaped element (44) between the flanges (41),(42) of a respective I- shaped element (40).

Each wall element (1) may be placed into two vertical s5 insertion shaped elements (44) of the wall construction by means of its vertical edges opposite each other and be

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i s l. c removed again after the I-shaped elements have been installed fixedly. To this end, the wall element (1) is first inserted, its upper edge inclined, into the vertical channel (43) of the insertion shaped element (44), then 5 rotated until the wall element is in the plane determined by the two insertion shaped elements (44) (44) and finally laterally shifted until its other edge is in the vertical channel (43) of the other insertion shaped element (44). to this end however, the wall elements (1) must have rather lo much vertical clearance. In order to avoid that because of this clearance, the wall elements (1) will be loose in the wall construction, a filling shaped element (45) is shifted into one of the vertical channels (see figures 18 and 22).

Because of this most of the vertical clearance is removed 15 (compensated) .

Preferably, the different parts of the sound absorbing wall elements and the wall are manufactured by means of an extrusion process. Of course, other processes are also 20 possible (such as pressure die-casting for instance). The advantage of an extrusion process is that this is a continuous process, by means of which products of any length desired may be produced.

Claims

.. À. . o. e . r . CLAIMS

1.- Sound absorbing wall element (1), comprising a body (2,3), substantially made of synthetic material with an 5 internal space (4) in which a sound absorbing material (5) has been provided, a number of passages (6) being provided in the body (2,3) running into the internal (4), characterized in that each passage (6) has at least one wall (8), moving away from the axis (7) of the passage (6), in lo the direction of the internal space (4) at a sharp angle (a).

2.- Sound absorbing wall element (1), according to claim 1, characterized in that the terminal part of each passage (6) 5 running into the internal space (4) widens in a funnel-shape in the direction of the internal space (4).

3.- Sound absorbing wall element (1), according to claim 2, characterized in that the terminal part of each passage (6) To running into the internal space (4) is made conical.

4.- Sound absorbing wall element (1), according to any one of the preceding claims, characterized in that the terminal part of the said passages (6) running to the outside of the z5 body (2,3) is made cylindrical.

5.- Sound absorbing wall element (1), according to any one of the preceding claims, characterized in that the body (2,3) comprises a first (2) and a second (3) part which are 30 detachable from one another and together enclose the said internal space (4).

6.- Sound absorbing wall element (1), according to claim 4, characterized in that the said first (2) and second (3) part 35 extend on the one side and on the other side of the sound absorbing material (5).

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7.- Sound absorbing wall element (1), according to any one of the preceding claims, characterized in that the relation between the surface of the passages (6) in a flank of the body (2,3) on the one hand and the total surface of the said 5 flank on the other hand lies between 20% and 4096 and preferably is about 30.

8.- Sound absorbing wall element (1), according to any one of the preceding claims, characterized in that the body lo (2,3) is provided with means (26,27,28)(38,39) to maintain the sound absorbing material (5) in a position at an intermediate distance away from the passages (6).

9.- Sound absorbing wall element (1), according to any one 5 of the preceding claims, characterized in that at least one outer wall of the body (2,3) is provided with an abrasive resistant coating.

10.- Sound absorbing wall element (1), according to any one 20 of the preceding claims, characterized in that the body (2,3) and the sound absorbing material (5) are carried out in a panel-shape.

11.- Sound absorbing wall element (1), according to any one 2s of the preceding claims, characterized in that at least one part (2) of the body (2,3) is made of cellular synthetic material.

12.- Sound absorbing wall element (1), according to any one 30 of the preceding claims, characterized in that the body (2,3) is substantially made of recycled synthetic material.

13.- Sound absorbing wall element (1), according to any one of the preceding claims, characterized in that the sound 35 absorbing material (5) is substantially made of synthetic material, more particularly of recycled synthetic material.

D, I, '.L I,.

14.- Sound absorbing wall element (1), according to any one of the claims 11 to 13, characterized in that the said material substantially consists of polyvinyl chloride.

5

15.- Sound absorbing wall comprising one or more sound absorbing panel elements (1) and a number of retaining elements (40); (50),(51),(52) to maintain the wall elements (1) in a position for use, characterized in that they are wall elements (1) according to the preceding claims.

16.- Sound absorbing wall according to claim 15, characterized in that it comprises a number of shell elements (45),(46),(47) which may be attached to the retaining elements (40) in order to cover parts of them, and 5 that these shell elements are made of synthetic material, more particularly of cellular synthetic material.

17.- Sound absorbing wall according to claim 16, characterized in that the retaining elements 20 (40);(50),(51), (52) are I-shapes elements and in that each shell element (45),(46),(47) is provided to enclose a flange (41),(42) of an I-shaped element.

18.- Sound absorbing wall according to any one of the claims 25 15 to 17, characterized in that each retaining elements (50),(51),(52) is substantially made of synthetic material, more particularly of a cellular synthetic material.

19.- Sound absorbing wall according to claim 18, 30 characterized in that the said synthetic material substantially consists of polyvinyl chloride.

20.- Sound absorbing wall according to any one of the claims 15 to 19, characterized in that it comprises several sound 35 absorbing wall elements (1) which one beside the other and/or one above the other and fitting together constitute

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Us C E. a.; the sound absorbing wall and in that on opposite sides of the sound absorbing wall elements (1) a protruding rib (25) and a groove (24) respectively are provided, so hat with two wall elements (1) fitting together the rib (25) of the one wall element (1) is situated in the groove (24) of the other wall element (1).