Patent Description:
As is known, the transit of vehicles along a road or a motorway creates noise. The noise is typically generated by the rolling movement of tyres, by air streams and aerodynamic noise, by vehicle engine noise and by the use of acoustic signalling devices or the like.

Along roads where there is particularly heavy traffic or in any case high noise levels it is known to install noise barriers in order to limit the noise in the area close to these roads. For example, when a roadway section is located close to a receiver (residence, school, hospital, etc.), a noise barrier is installed in order to limit the noise coming from the road and make the noise level acceptable for those persons living in the affected receiver.

The noise barriers may be installed close to roads and motorways, but also close to other sources of noise and/or noise pollution. For example, they may be installed close to railways lines or airport runways or industrial zones.

Typically, a known noise barrier is composed of panels installed on a special structure which is secured and/or fixed onto a suitable support.

The panels may be of the sound-insulating and/or sound-absorbing type. Sound-insulating panels are able to lessen the noise levels produced by the sound source in the region of the receivers affected by the noise. In some cases, sound-insulating panels may also be characterized by sound-absorbing properties, i.e. the capacity to absorb the sound energy generated by the noise source. The effectiveness of the screening system depends on the sound characteristics of the panels and the geometric structure of the noise barrier.

<CIT>, <CIT>, <CIT>, <CIT>, <CIT> and <CIT> disclose sound-insulating barriers.

The object defined by the Applicant is that of imparting also sound-absorbing properties to sound-insulating barriers. This object, together with other objects, is achieved by adding modules which are fastened to the screening wall elements and which are able to absorb and spread the incident sound energy over a wide frequency range. According to embodiments, the modules have a wave-shaped form.

According to a first aspect the present invention provides a noise barrier as defined in claim <NUM>. At least one of the sound-absorbing panels has a wavy profile in cross-section along its length, with a single peak corresponding to a maximum thickness and two half valleys corresponding to the minimum thickness and a height lower than the height of the support uprights. The aforementioned shape of the sound-absorbing panel is able to spread the incident sound energy and disperse it in multiple directions, avoiding the concentration of sound energy by reflection on the front receivers.

According to embodiments, the single peak is in correspondence with a central section of at least one of the sound-absorbing panels and each of the two half-valleys is near a respective end of the sound-absorbing panel.

According to embodiments, at least one of the sound-absorbing panels comprises a layer of sound-absorbing material. Advantageously, the layer of sound-absorbing material has a substantially constant thickness and is arranged so as to follow the wavy profile.

According to embodiments, at least one of the sound-absorbing panels comprises a box-like body.

According to embodiments, the layer of sound-absorbing material is arranged inside the box-like body. According to embodiments, a substantially empty gap is formed in the box-like body between the layer of sound-absorbing material and the sound-insulating wall, at least at the peak. The cavity is advantageous for enhancing the sound absorption characteristics and extending the sound absorption properties even at low frequencies.

According to embodiments, the surface exposed to a noise source is perforated and/or comprises an expanded metal sheet and/or comprises a mesh or the like.

According to embodiments, at least one sound-absorbing panel is hooked onto and suspended from the wall elements by means of a bracket fixed to the wall elements. The suspended hooked arrangement of the sound-absorbing panels is particularly advantageous as it allows the replacement of the single sound-absorbing panel, typically to perform maintenance activities, without the need to disassemble the adjacent panels.

According to embodiments, the bracket comprises an upper slot and a lower hook and wherein the panel comprises an upper L-shaped plate configured to engage with the slot of the bracket and a lower L-shaped plate configured to engage with the lower hook of the bracket.

According to another aspect, the present invention provides a method for assembling a noise barrier as defined in claim <NUM>.

According to embodiments, the sound-absorbing panels are arranged staggered or unstaggered with respect to the immediately adjacent panels.

The present invention will become entirely clear from the following detailed description, provided purely by way of a non-limiting example, to be read with reference to the attached sets of drawings in which:.

<FIG> shows in schematic form a sound-insulating base wall section. According to embodiments, the sound-insulating wall <NUM> may comprise wall elements <NUM> and support uprights <NUM>.

The support uprights <NUM> may be metal uprights placed at a predetermined distance from each other. Advantageously, the support uprights <NUM> are arranged in a vertical position and may be stably fixed to the ground, for example to a concrete base.

According to embodiments, the metal uprights <NUM> are iron or steel sections with an "I" (or double "T") cross-section of the type HEB <NUM>, <NUM> or <NUM>.

According to embodiments, the wall elements <NUM> are rectangular elements with a thickness, at least along their short sides, such that the can be inserted between the flanges of the HEB <NUM> upright.

The wall elements <NUM> may be made of any type of material, such as concrete, wood, polymethyl methacrylate (PMMA) and steel.

According to the present invention sound-absorbing panels <NUM> are superimposed on the sound-insulating base wall <NUM>. As will become clear below, the sound-absorbing panels <NUM> may be made of various materials. <FIG> shows the sound-insulating wall <NUM> with a plurality of wave-shaped panels which cover it partially and <FIG> shows the sound-insulating wall <NUM> which is completed lined with wave-shaped panels.

The sound-absorbing panels <NUM> may be made of different materials such as expanded sheet metal, as shown in <FIG>.

The sound-absorbing panels <NUM> may be made of different materials such as Krion, as shown in <FIG>.

Each wall element <NUM> may be made as one piece or consist of two or more modules.

According to the embodiments of the present invention, the sound-absorbing panels <NUM> have a substantially elongated form, with a variable cross-section having a sinusoidal progression. In other words, the visible surface of the panel <NUM> does not lie in one plane, but extends so as to form peaks and valleys. Preferably, the progression of the panels <NUM> is very curvy, very "gentle", with very rounded peaks and valleys.

According to embodiments, panels <NUM> with different lengths are provided. According to other embodiments, most (or all) of the panels <NUM> have the same length.

The sound-absorbing panels may be mounted on a wall <NUM> so that they are aligned, i.e. with the peaks of all the panels <NUM> aligned with each other. In other embodiments, the peaks may be unaligned. For example, opposite the peak of one panel, there could be a valley of the adjacent upper (or lower) panel. This staggered configuration is considered to be advantageous for favouring the diffusion of the reflected sound. Furthermore it provides a pleasing aesthetic "moving" effect.

The sound-absorbing panels <NUM> may have the same height or may have different heights.

Preferably, the panels <NUM> have dimensions which are substantially fractions or multiples of the dimensions of the walls.

<FIG> is an exploded view of a wave-shaped sound-absorbing panel <NUM> according to embodiments of the invention.

The panel <NUM> comprises, by way of example, a box-like body <NUM> and a layer <NUM> of sound-absorbing material inside the box-like body <NUM>. The panel <NUM> is configured to be secured to a bracket <NUM> which is in turn fastened to a wall <NUM>.

The box-like body <NUM> typically comprises a perforated front face, for example made of expanded sheet metal or Krion. The box-like body <NUM> preferably comprises side walls <NUM>, <NUM> and a top closing part <NUM> and bottom closing part <NUM>. According to preferred embodiments, the box-like body <NUM> comprises reinforcing partitions <NUM>.

The sound-absorbing material <NUM> may comprise a layer of natural and/or synthetic sound-absorbing material with a thickness which is suitable for the desired absorption characteristics. For example, the sound-absorbing material <NUM> may comprise a material such as rockwool, polystyrene or polyester. According to embodiments, the thickness of the sound-absorbing material <NUM> may be between <NUM> and <NUM>.

According to the embodiment shown in <FIG>, the front face <NUM> comprises an expanded metal sheet made of steel, or a mesh. According to embodiments, the holes in the expanded metal sheet or mesh are substantially hexagonal, circular, rhombus-shaped or oval. According to other embodiments, the front face <NUM> of the sound-absorbing panel <NUM> comprises a metal sheet suitably perforated with a predefined pattern.

The sound-absorbing panels <NUM> may be fastened using any means to the sound-insulating base walls <NUM>. According to embodiments, securing brackets <NUM> are provided, these being fixed to the sound-insulating base walls <NUM> so that a panel <NUM> may be fastened to two or brackets <NUM>, in a suspended (projecting) configuration.

<FIG> show by way of example a bracket <NUM> for securing sound-absorbing panels <NUM> to a sound-insulating base wall <NUM>. The bracket <NUM>, advantageously, has a C-shaped form in cross-section, with two flanges <NUM> and a central strip <NUM> provided with holes (<FIG>) for connection (for example by means of screws) to the sound-insulating wall. The bracket <NUM> may be made of metallic material such as steel, aluminium or alloys thereof.

At the top end, each of the two flanges <NUM> has a slot <NUM>, as shown in <FIG>.

At the bottom end, each of the two flanges <NUM> has a hook <NUM> with a nose <NUM>, as shown in <FIG>.

<FIG> illustrate, in schematic form, the steps of securing a sound-absorbing panel <NUM> to a bracket <NUM>. Typically the rear face of the sound-absorbing panel <NUM> comprises an upper L-shaped plate <NUM> and a lower L-shaped plate <NUM> facing each other.

During a first step (<FIG>) the rear of the sound-absorbing panel <NUM> is moved towards the bracket <NUM>.

During a second step (<FIG>), the lower L-shaped plate <NUM> is pushed so as to engage with the lower hook <NUM> of the bracket <NUM>.

During a third step (<FIG>), the sound-absorbing panel <NUM> is pushed upwards and at the same time rotated so that the upper L-shaped plate <NUM> is situated opposite the upper slot <NUM> of the bracket <NUM>. The rotational movement is possible also owing to the shape of the nose <NUM> of the lower hook <NUM>, as can be seen from the series of figures.

During a fourth step (<FIG>), the sound-absorbing panel <NUM> is pushed downwards so that the upper L-shaped plate <NUM> fully engages inside the upper slot <NUM>. During this step, the lower L-shaped plate <NUM> remains engaged with the lower hook <NUM>.

<FIG> shows the panel <NUM> suspended by means of the bracket <NUM>.

Means may be provided for preventing the sound-absorbing panels from being disengaged, for example following acts of vandalism.

As will be clear from the description above, the noise barrier <NUM> according to the present invention, compared to the known noise barriers, has the particular feature that, geometrically speaking, it has a novel design owing to the combination, on two different levels, of a sound-insulating base wall and sound-absorbing panels superimposed thereon. This twin-panel superimposed arrangement gives the noise barrier a three-dimensional appearance on the road.

The sound-absorbing panels <NUM> according to the invention may be installed, if necessary, also on a barrier already present along the road, without resulting in any structural deterioration thereof.

Depending on the surrounding landscape in the which the barrier must be inserted, a basic material which best characterizes the surroundings may be chosen.

The nose barrier according to the invention is intended for applications in which a partial or total sound-absorbing performance is required. The different levels of sound absorbance may be achieved by varying the number of sound-absorbing panels which are inserted and the characteristics of the sound-absorbing material included inside the panels (material, thickness and density).

This noise barrier with a novel design is extremely modular and versatile and, where necessary, its acoustic performance features may be extended also to the rear side of the barrier by means of the positioning of further sound-absorbing panels, so as to provide suitable screening and acoustic comfort where neighbouring noise sources are present.

The strong visual identity represented by the design of the barriers according to the invention is increased by the possibility of including a company logo in its various formulations and sizes.

Claim 1:
A noise barrier (<NUM>) comprising a sound-insulating base wall (<NUM>) comprising a plurality of support uprights (<NUM>) and a plurality of wall elements (<NUM>) supported by said support uprights (<NUM>), the noise barrier (<NUM>) further comprising elongated sound-absorbing panels (<NUM>) superimposed on the sound-insulating base wall (<NUM>), characterized in that the elongated sound-absorbing panels (<NUM>) have a non-uniform thickness along their length, wherein at least one of the elongated sound-absorbing panels (<NUM>) has a wavy profile in cross-section along its length with a single peak corresponding to a maximum thickness and two half valleys corresponding to the minimum thickness and a height lower than the height of the support uprights (<NUM>).