Patent Description:
Covering panels made of rigid material have long been used to cover architectural building elements, for example internal or external walls, or also to cover furnishing elements such as bedside tables, tables, desks and suchlike.

Sometimes, the panel functions as a support surface, such as for example in the case of a desk or table. In this case, the advantage derived from the use of the panel is often of an aesthetic nature.

Among the panels used for covering or support purposes, those made of glass are particularly appreciated for their qualities of beauty and elegance, or for their robustness that allows them to be used as a reinforcement plate for a covering plate in a different and fragile material.

To be used in covering panels in the building trade, the glass plates must have a predetermined thickness, possibly based on the length and width of the glass plate. The thickness of the plate can increase with its lateral sizes, in order to guarantee a certain solidity to the glass plate.

At the time of their installation, the panels are attached to a bearing structure, for example the legs of a table or desk, or brackets attached to a wall.

The panels are attached to the bearing structures by means of bushings which are glued to the panels, and which in turn are attached to the bearing structure, for example by means of a threaded through hole made in the bearing structure.

One disadvantage of this attachment solution is that its strength depends on the gluing of the bushings to the panel. The gluing is usually not strong enough to ensure a stable long-term attachment. In fact, sometimes the bushings become unglued from the panel, for example due to stress caused by situations of prolonged fatigue or by variations in environmental conditions, in particular variations in temperature or pressure.

In general, this attachment solution also has the disadvantage of resulting in one or more bushings that protrude from the plane of the front plate of the panel, which can be considered not very aesthetic.

Document <CIT> describes a laminated glass panel comprising an attachment screw inserted into a seating or bushing provided through in one of the plates and disposed protruding with respect thereto.

Document <CIT> describes a laminated glass panel, comprising two glass plates and a truncated cone-shaped attachment plate, which is inserted into a mating shaped seating made through in one of the plates and is disposed protruding with respect to the latter. The panel described in <CIT> also comprises a layer of plastic material disposed between the two glass plates.

<CIT> describes a panel comprising a first and a second glass plate separated by an intermediate polymeric layer, and an attachment element inserted into the intermediate layer and disposed in a through manner through a cylindrical hole provided in the second glass plate. <CIT> discloses a multilayer panel comprising a covering plate, a reinforcing plate, and an attachment element.

There is therefore a need to perfect a multilayer panel which can overcome at least one of the disadvantages of the state of the art.

In particular, one purpose of the present invention is to provide a multilayer panel, equipped with at least one glass plate which acts as a reinforcing plate, which can be attached in a stable and secure manner over time.

Another purpose is to provide a multilayer panel which allows the covering plate to be left intact.

In accordance with the above purposes, hereafter we describe embodiments of a multilayer panel which overcomes the limits of the state of the art and eliminates the defects present therein.

In accordance with some embodiments, a multilayer panel is provided comprising a covering plate and at least one reinforcing plate. The latter is associated with the covering plate. In particular, the covering plate and the reinforcing plate are coupled to each other in correspondence with a respective surface or face thereof. In other words, the covering plate and the reinforcing plate are overlapping, not adjacent.

The multilayer panel comprises one or more attachment elements, placed in correspondence with as many attachment points, for its attachment to a support structure. The one or more attachment elements is/are inserted in the reinforcing plate only.

The covering plate is not modified, at least in correspondence with its surfaces.

The attachment element is disposed flush, or possibly recessed, with respect to the external surface of the reinforcing plate.

The panel comprises one or more seatings to house the attachment elements. More preferably, these seatings are made only in the reinforcing plate. The seatings each comprise a hole made through the reinforcing plate. The seatings are advantageously closed, at their bottom, by the covering plate.

The attachment element and the seating are provided with respective rotation blocking means, configured to engage with each other to block the attachment element, preventing a rotation thereof around its axis of development. Thanks to the rotation blocking means, it is easier to insert a screw in the attachment element and screw it thereto when the attachment element is inserted between the two plates, and therefore it is no longer accessible for an operator, making the assembly operations easier and faster.

According to some embodiments, each seating comprises a first portion which extends from the free surface of the reinforcing plate to an intermediate section of the seating, and a second portion, or bottom portion, which extends from the above said intermediate section to the bottom of the seating.

Advantageously, the second portion is configured so as to form at least one abutment element to abut the attachment element, more advantageously an abutment counter-element of the attachment element, and prevent it from coming out of the seating. More advantageously, the second portion has at least one section the lateral size of which is larger than the lateral size of the intermediate section. Even more advantageously, the second portion has a truncated conical shape diverging from the intermediate section to the bottom of the seating.

By lateral size we mean the greater distance between two perimeter points taken in a same section perpendicular to the axis of development of the seating.

Preferably, the first portion of the seating is cylindrical.

Preferably, the attachment element comprises as well a first portion that extends from a first end thereof to an intermediate section thereof, and a second portion that extends from the same intermediate section to a second end thereof. More preferably, the second portion comprises at least one section the lateral size of which is larger than the lateral size of the first portion. Even more preferably, the second portion of the attachment element has a truncated cone shape that diverges from the intermediate section to the second end.

It is desirable for the second portion of the attachment element to have a shape and length that correspond to the shape and length of the second portion of the seating. Even more appropriately, the shape and sizes of the attachment element correspond to the shape and sizes of the seating.

More appropriately, the seating and the attachment element have shapes that correspond to each other, so as to obtain a same-shape coupling.

Preferably, the first portion of the seating and the first portion of the attachment element have shapes that correspond to each other, and the second portion of the seating and the second portion of the attachment element have shapes that correspond to each other.

Advantageously, the attachment element comprises a bushing provided with a threaded hole.

In accordance with some embodiments, the multilayer panel also comprises an interlayer disposed between the reinforcing plate and the covering plate. Preferably, the interlayer comprises a sheet of plastic material.

According to one aspect, there is also provided a method to assemble a multilayer panel, which comprises the steps of supplying a covering plate, supplying a reinforcing plate provided with one or more through seatings, inserting an attachment element in each of the seatings, and subsequently associating the reinforcing plate and the covering plate. This association determines the closure of the seatings. Moreover, during the insertion of the attachment element, the method provides to engage respective rotation blocking means with each other, respectively provided on the attachment element and in the seating in order to prevent a rotation of the attachment element around an axis of development thereof.

According to one aspect of the invention, the method provides to insert the attachment element flush with, or at most recessed with respect to, the external surface of the reinforcing plate. This conformation allows to prepare the panel directly in a first site and transport it in assembled form to a second site, where it can be associated with respective supports by means of screws inserted and screwed into each attachment element.

It can be provided that the reinforcing plate is not provided with the insertion seatings. In this case, it is provided to make one or more insertion seatings in the reinforcing plate, obviously before inserting the attachment elements.

Preferably, the attachment element and the seating have shapes that correspond to each other, so as to obtain a same-shape coupling.

Preferably, the method also comprises, before the step of associating the reinforcing plate with the covering plate, a step of disposing an interlayer between the reinforcing plate and the covering plate.

Some embodiments described here also concern a table comprising a multilayer panel according to the invention, comprising a plurality of seatings disposed in correspondence with attachment points, in each of said seatings there being disposed a respective attachment element, a bearing structure provided with respective through holes in correspondence with the attachment points as above and a plurality of screws inserted in the through holes and screwed to respective internal threads of the attachment elements.

It is understood that elements and characteristics of one embodiment can conveniently be combined or incorporated into other embodiments without further clarifications. The embodiment shown in <FIG> is not covered by the claimed invention.

<FIG> shows a multilayer panel, indicated as a whole with reference number <NUM>.

The multilayer panel <NUM> is composed of at least one covering plate <NUM> and one reinforcing plate <NUM>, the two plates <NUM>, <NUM> being associated with each other. This association can be performed, for example, by gluing the plates <NUM>, <NUM> with an adhesive substance.

Each plate <NUM>, <NUM> comprises two surfaces opposite each other and delimited by one or more edges, depending on their shape. The two plates <NUM>, <NUM> are associated in correspondence with a respective surface thereof. In other words, the association of the two plates <NUM>, <NUM> is made by reciprocally associating one surface of the covering plate <NUM> with one surface of the reinforcing plate <NUM>.

It is possible to provide that the panel <NUM> consists of several covering plates <NUM> and/or several reinforcing plates <NUM>, depending on the uses for which the panel <NUM> is intended.

The multilayer panel <NUM> shown in the drawings is rectangular in shape; however, it is possible to provide that the panel <NUM> be of any shape whatsoever, for example square, circular or oval, without departing from the field and scope of this description.

The panel <NUM> is designed so that, when installed, the covering plate <NUM> is exposed to view, that is, it acts as a covering, and that the reinforcing plate <NUM> is oriented toward a bearing structure <NUM>, to which the panel <NUM> is to be attached (<FIG>). The bearing structure <NUM> can be of any type whatsoever, depending on the intended use of the multilayer panel <NUM>, for example a bracket to attach the panel <NUM> to a wall, legs for a table, or other.

The covering plate <NUM> is preferably made of glass, for example normal glass or tempered glass, but it can also be made of another material. The reinforcing plate <NUM> can also be made of glass, tempered or not, or other materials such as, for example, ceramic, plexiglass, other types of synthetic glass or suchlike. Preferably, the reinforcing plate <NUM> is made of a material which has characteristics of resistance equal to or greater than those of the covering plate <NUM>.

In order to allow its attachment to a bearing structure <NUM>, the multilayer panel <NUM> comprises one or more attachment elements <NUM>, inserted or integrated therein. Each attachment element <NUM> is inserted in a respective insertion seating <NUM>, and the seatings <NUM> are located in correspondence with as many predefined attachment points <NUM> according to the geometry and sizes of the multilayer panel <NUM>, and/or its intended use.

For example, as can be seen in <FIG> and <FIG>, in the case of a multilayer panel <NUM> with a rectangular shape, four attachment points <NUM> can be provided, for example in the proximity of the four corners of the panel <NUM>, and in correspondence with which the seatings <NUM> have been made.

The positioning of the attachment points <NUM> is decided in a known manner.

Advantageously, the seatings <NUM> each comprise a positioning and clamping hole <NUM> of the attachment element <NUM>, configured to position the attachment element and clamp it in the multilayer panel <NUM>.

The positioning and clamping holes <NUM> are made only in the reinforcing plate <NUM>, not in the covering plate <NUM>. Thus, the covering plate <NUM>, which is provided so as to be exposed to public view, is left intact, that is, without any modifications to its original appearance.

More preferably, the holes <NUM> are made through in the reinforcing plate <NUM>. As such, they have their own axis of development A (<FIG>) and have an aperture <NUM> and a bottom <NUM>. The aperture <NUM> is disposed in correspondence with the free surface of the reinforcing plate <NUM>, that is, the surface that is not associated with the covering plate <NUM>. The bottom <NUM>, on the other hand, provides another aperture in correspondence with the surface of the reinforcing plate <NUM> associated with the covering plate <NUM>.

Since the reinforcing plate <NUM> is associated with the covering plate <NUM>, the bottom <NUM> of the hole <NUM> is closed by the covering plate <NUM> (<FIG>).

In accordance with some embodiments, the positioning and clamping hole <NUM> is divided into at least two portions <NUM>, <NUM> which join in correspondence with an intermediate cross section <NUM>. By intermediate cross section <NUM> we mean that this section is located between the aperture <NUM> and the bottom <NUM> of the seating, for example substantially halfway between these two ends of the hole <NUM>.

The intermediate section <NUM> is advantageously a section transverse to the axis of development A of the hole <NUM>, more advantageously it is perpendicular to the axis of development A.

The first portion <NUM> extends from the aperture <NUM> to the intermediate section <NUM>, and the second portion <NUM> extends from the intermediate section <NUM> to the bottom <NUM> of the hole <NUM>.

Advantageously, the second portion <NUM> is configured so as to form at least one abutment element to abut against at least one section or an abutment counter-element of the attachment element <NUM>.

For example, it can be provided that the second portion <NUM> has at least one cross section with a lateral size greater than the lateral size in correspondence with the intermediate section <NUM>. In this way, for example, a shoulder can be obtained in the second portion <NUM>, or in correspondence with the intermediate section <NUM>, which holds the attachment element <NUM>.

In the example shown, the seating has a second portion <NUM> with a truncated cone shape, diverging from the intermediate section <NUM> to the bottom <NUM>. The first portion <NUM>, on the other hand, has a cylindrical shape. The latter can have another shape, as long as it allows the insertion of the attachment element <NUM>, and preferably as it has at least one cross section with a lateral size greater than or equal to the intermediate section <NUM>.

In this way, the second portion <NUM> has an internal wall <NUM> inclined with respect to the axis of development A, and which acts as an abutment element for the attachment element <NUM>.

It should be noted that in the above example, since the portions <NUM>, <NUM> have a cylindrical and truncated cone shape respectively, the lateral size corresponds to the diameter taken in a section perpendicular to the axis of development A. We wish to reiterate that the first portion <NUM> and the second portion <NUM> can have sections of any shape whatsoever depending on requirements, and can have different shapes from each other, so as to clearly separate the two portions <NUM>, <NUM>, or have shapes mating with each other so as to define a single overall shape of the seating <NUM>.

For example, it can be provided that both the second portion <NUM> and also the first portion <NUM> have a truncated cone shape which, located one after the other, define a single conical or truncated conical shape of the seating <NUM>.

Preferably, the attachment element <NUM> has a shape and sizes that correspond to the shape and sizes of the hole <NUM>.

The attachment element <NUM> comprises a body that extends along an axis of development B between a first end <NUM> and a second end <NUM> (<FIG>). The attachment element <NUM> is configured so that, once installed in the hole <NUM>, the first end <NUM> is located in correspondence with the aperture <NUM>, and the second end <NUM> is located in the bottom <NUM> of the hole <NUM> (<FIG>). Preferably, the length of the attachment element <NUM>, which is the distance between its two ends <NUM>, <NUM> taken along the axis of development B, is equal to the thickness of the reinforcing plate <NUM>, that is, the distance between the aperture <NUM> and the bottom <NUM> of the positioning and clamping hole <NUM> along the axis of development A.

In the event that several reinforcing plates <NUM> are present, the length of the attachment element <NUM> is preferably equal to the thickness of all the reinforcing plates <NUM>.

Advantageously, also the attachment element <NUM> is divided into two portions <NUM>, <NUM> which join in correspondence with an intermediate section <NUM> of the body. Preferably, the first portion <NUM> extends from the first end <NUM> to the intermediate section <NUM>, and the second portion <NUM> extends from the intermediate section <NUM> to the second end <NUM> of the attachment element <NUM>.

More advantageously, the first portion <NUM> of the attachment element <NUM> is configured to be inserted in the first portion <NUM> of the hole <NUM>, and the second portion <NUM> of the attachment element <NUM> is configured to be inserted in the second portion <NUM> of the hole <NUM>.

The second portion <NUM> of the attachment element <NUM> preferably comprises an element configured to interact with the abutment element of the second portion <NUM> of the hole <NUM>. More preferably, the second portion <NUM> of the attachment element <NUM> has at least one section with a lateral size larger than the lateral size of the intermediate section <NUM>.

Preferably, the attachment element <NUM> has the shape of a solid of revolution. More preferably, the hole <NUM> has a shape such as to house the attachment element <NUM> according to a same-shape coupling.

In the example shown, the second portion <NUM> of the attachment element <NUM> has a truncated cone shape and diverges from the intermediate section <NUM> toward the second end <NUM>. The second portion <NUM> has an external wall <NUM> inclined with respect to the axis of development B of the attachment element <NUM>, and which during use abuts against the internal wall <NUM> of the second portion <NUM> of the hole <NUM> (<FIG>).

In this case, therefore, the inclined internal wall <NUM> of the hole <NUM> constitutes the abutment element, and the inclined external wall <NUM> of the attachment element <NUM> constitutes the abutment counter-element. Obviously, other shapes and configurations of abutment element and counter-element can be provided.

As can be seen in <FIG>, the first and second portions <NUM>, <NUM> of the attachment element <NUM> have a shape and sizes which correspond respectively to the shape and sizes of the first and second portions <NUM>, <NUM> of the hole <NUM>. It is therefore possible to perform a same-shape coupling between the attachment element <NUM> and the hole <NUM>.

In the example shown, the attachment element <NUM> is of the bushing type. It comprises an internal thread <NUM> as an attachment element, made coaxial to the attachment element <NUM> and configured to be associated with a corresponding screw <NUM> (<FIG>) as an attachment counter-element.

The internal thread <NUM> preferably extends over the entire height of the attachment element <NUM>.

The attachment elements <NUM> are advantageously made of a rigid and robust material, preferably softer than glass. For example, the attachment elements <NUM> are made of an aluminum alloy that can adapt to the shape of the glass.

According to some embodiments, the multilayer panel <NUM> also comprises an interlayer (not shown in the drawings) interposed between the covering plate <NUM> and the reinforcing plate <NUM>. This interlayer can comprise a sheet of plastic material which is made to adhere to both the covering <NUM> and reinforcing <NUM> plates.

The plastic material can be, for example, polycarbonate, polyvinyl butyral and/or polyvinyl acetate or suchlike.

In addition to the advantages of integrating the attachment elements <NUM> and of the solidity of the attachment that they allow, compared to the state of the art, another advantage related to the present invention has been discovered.

It is known that glass plates can be heat treated in an oven at temperatures higher than <NUM>, for example <NUM>. During this heat treatment phase, the glass plates are deformed, even more so when they have a certain thinness or a certain geometric shape. In particular, the glass plates are curved or rounded, as shown schematically in <FIG>, in which the covering plate <NUM> is shown flat with a solid line and curved with a broken line, with the curvature deliberately enlarged, for illustrative purposes only. This curvature may be due to various factors, for example a coupling of two plates made of different materials that react differently to heat.

Generally, the rounding of the glass plate results from thrust or traction forces exerted in different thrust or traction points <NUM> typically disposed in intermediate positions between the attachment points <NUM>.

It has been discovered that, surprisingly, the multilayer panel <NUM> as described above allows to perform an adjustment of the curvature of the glassplate, and therefore of the panel <NUM>. In fact, with the idea underlying the present invention, it becomes possible to attach the panel <NUM> by means of screws, as in the example described above.

By acting on the screwing, it is possible to modulate the force applied in correspondence with the attachment points <NUM>, for example in order to decrease the curvature of the panel. This allows, for example in the case of a table with a glass top, to also provide glass extensions that integrate better with the surface of the table itself.

It should be noted that any number of holes <NUM> and corresponding attachment elements <NUM> can be provided in the reinforcing plate <NUM>. In particular, it is possible to provide bushings <NUM> that effectively serve to attach the multilayer panel <NUM> to a bearing structure <NUM> (also called constraints), but also bushings <NUM> that serve exclusively to modulate the traction and thrust forces undergone by the panel <NUM> (also called adjustment points). It is also possible to provide bushings <NUM> to attach other elements to the panel <NUM>, such as for example attachment elements to attach the multilayer panel <NUM> to the bearing structure <NUM>, instead of attaching it directly.

A method to mount a multilayer panel <NUM> according to the previous description is described below.

First of all, a covering plate <NUM> and a reinforcing plate <NUM> are provided, and possibly a sheet of plastic material as an interlayer.

Preferably, the reinforcing plate <NUM> is already provided with the positioning and clamping holes <NUM> which form the insertion seatings <NUM> for the attachment elements <NUM>, and which have been made for example by means of drilling. More preferably, the holes <NUM> are as described above, and as shown in the drawings.

Some attachment elements <NUM> are also supplied, for example some bushings, the shape of which corresponds to the shape of the holes <NUM>, and in a number equal to the number of holes <NUM>.

Before reciprocally associating the covering <NUM> and reinforcing <NUM> plates, an attachment element <NUM> is inserted in each of the positioning and clamping holes <NUM>.

Once the attachment elements <NUM> have been positioned, the interlayer sheet of plastic material, if provided, is placed on top of the reinforcing plate <NUM> in order to close the bottoms <NUM> of the holes <NUM>, whereby completing the formation of the seatings <NUM>. Subsequently, the covering plate <NUM> is placed on top and the plates <NUM>, <NUM> are reciprocally joined.

We wish to point out that the reciprocal joining of the plates <NUM>, <NUM> determines the closure of the bottom <NUM> of the holes <NUM>, completing the formation of the seatings <NUM>. At this point, the bushings <NUM> are kept in fixed positions on one side by the covering plate <NUM>, which closes the bottom <NUM> of the hole <NUM>, and on the other side by the internal wall <NUM> of the hole <NUM> which, since it is inclined, abuts against the external wall <NUM>, also suitably inclined, of the bushing <NUM>.

Once the plates <NUM>, <NUM> have been joined, the panel <NUM> is ready to be mounted on a bearing structure <NUM>. The latter is preferably provided with through holes <NUM> in correspondence with the attachment points, and disposed so as to correspond to the seatings <NUM> of the panel <NUM> (<FIG>).

The panel <NUM> is then placed on or against the bearing structure <NUM>, taking care to align the through holes <NUM> of the bearing structure <NUM> with the threads <NUM> of the bushings <NUM>. The attachment is carried out by inserting screws <NUM> in the threads <NUM>, making them pass through the through holes <NUM> of the support structure <NUM> (<FIG>).

Preferably, the screws <NUM> are screwed so that the panel <NUM> is attached to the support structure <NUM> in a stable manner. It is also possible to provide to act (screw or unscrew) further in order to increase the forces on the panel <NUM> in correspondence with the attachment points <NUM>, so as to contrast and decrease the curvature of the multilayer panel <NUM>.

From the previous description it is clear that the present invention allows to equip a multilayer panel <NUM> with attachment elements <NUM> that are totally integrated, and disposed in a stable manner inside the panel. As well as not compromising the appearance of the covering plate, the solution underlying the invention allows an attachment of the multilayer panel <NUM> that is stable and durable over time.

The stability of the attachment is achieved at least because the bushings <NUM> are totally inserted in the reinforcing plate <NUM>, and cannot move inside the holes <NUM>. The fact that the bushings <NUM> and the holes <NUM> have corresponding shapes contributes to this advantageous aspect.

<FIG> show the embodiment of the invention. The elements in common with the first embodiment are not described again, and have the same reference numbers to which a single quote mark has been added.

According to the invention, the attachment element <NUM>' and the positioning and clamping hole <NUM>' are provided with respective rotation blocking means <NUM>', <NUM>', configured to engage with each other to block the attachment element <NUM>' preventing a rotation thereof around its axis of development B'.

In accordance with the embodiment of the invention, the attachment element <NUM>' comprises a rotation blocking member <NUM>', suitable to prevent its rotation around its axis of development B'. This makes it much easier to insert screws in it. This solution is advantageous since the bushing <NUM>', once inserted in its positioning hole <NUM>', is no longer accessible to the operator, therefore its possible rotation cannot be blocked manually.

Preferably, the rotation blocking member <NUM>' comprises a tooth that protrudes radially from the bushing <NUM>', preferably from its second section <NUM>'. In the example shown, the tooth has an upper surface <NUM>' which protracts from the surface of the second end <NUM>' of the bushing <NUM>'. This form, although more advantageous, is not mandatory.

In the embodiment of the invention, the positioning and clamping hole <NUM>' is provided with a rotation blocking seating <NUM>' configured to accommodate the rotation blocking member <NUM>', and to supply at least one abutment element in order to block its rotation around the axis B'. In the example shown, the rotation blocking seating <NUM>' extends radially from the positioning and clamping hole <NUM>', more preferably from its second portion <NUM>'.

The rotation blocking seating <NUM>' preferably has a shape that is complementary to the shape of the rotation blocking member <NUM>', so as to obtain a same-shape coupling between them.

It is clear that modifications and/or additions of parts or steps may be made to the multilayer panel <NUM> and to the method as described heretofore, without departing from the field and scope of the present invention as defined by the claims.

Claim 1:
Multilayer panel (<NUM>) comprising a covering plate (<NUM>), at least one reinforcing plate (<NUM>), and at least one attachment element (<NUM>, <NUM>'), comprising at least one insertion seating (<NUM>) for said attachment element (<NUM>, <NUM>'), said insertion seating (<NUM>) comprising a positioning and clamping hole (<NUM>, <NUM>') of said attachment element (<NUM>, <NUM>') made only in said reinforcing plate (<NUM>) and said attachment element (<NUM>, <NUM>') being positioned in said positioning and clamping hole (<NUM>, <NUM>') flush with, or at most recessed with respect to, an external surface of said reinforcing plate (<NUM>), said multilayer panel (<NUM>) being characterized in that said attachment element (<NUM>') and said positioning and clamping hole (<NUM>') are provided with respective rotation blocking means (<NUM>', <NUM>'), configured to engage with each other to block the rotation of said attachment element (<NUM>') around an axis of development (B') thereof.