FR3115722A1 - Part in mineral and/or composite material with sharp re-entrant angle - Google Patents

Abstract

The invention relates to a part (1) made of mineral or composite material having two contiguous sides (2a, 2b) defining between them a re-entrant angle. According to the invention, the two sides (2a, 2b) belong to the same one-piece part (2) of the part (1), the two sides (2a, 2b) are connected to each other by a curve ( 4) replacing a sharp re-entrant angle so as to avoid incipient fractures in the material, and the part (1) comprises an added element (3) having, on the one hand, an internal portion which fills a space corresponding to the curve (4) and, on the other hand, an outer portion defining a sharp edge of the re-entrant angle. Figure for abstract: Fig. 6

Description

Part in mineral and/or composite material with sharp re-entrant angle

The invention relates to the technical field of the manufacture of objects in mineral material, or in composite material.

In general, the invention relates to the manufacture of parts based on any type of mineral material, such as granite, marble, glass, ceramics, etc. or in composite material with or without mineral filler, or in non-metallic and inorganic material, or more generally in any material in which a sharp re-entrant corner cutout creates incipient fractures.

Prior art

It is known in the field of the manufacture of objects in mineral or composite material from mineral material that it is necessary to avoid producing a one-piece part having a sharp re-entrant angle, that is to say an angle whose measurement on the side of the material is more than 180° and whose edge is not rounded by a fillet.

Indeed, such a zone is a zone of stress concentration and corresponds to a zone of fragility of the part where incipient fractures can be created which can lead to the ruin of the part.

In the particular case of worktops, coming for example to equip a kitchen, when the top has a re-entrant shape, such as an "L" or "U" shape, it is not possible to achieve this shape of "L" or "U" by cutting within a single plate. An “L” shape, for example, is therefore conventionally obtained by assembling two plates. The re-entrant angle of the “L” shape is obtained by assembling these two plates, which then presents a sharp edge. In the case of a sink, it is an "O" shape.

However, this method is not satisfactory because the work plan obtained has an edge between the two plates which is visible and unsightly.

It can be envisaged to make a simple fillet, that is to say an outgoing curve, at the level of the edge of the re-entrant angle, but the aesthetics of the part is degraded because the goal to be achieved is to present a re-entrant angle whose edge is sharp.

One of the aims of the invention is to provide a part made of mineral or composite material from mineral material, having a re-entrant angle in a one-piece part, for example a right angle, without creating any incipient fracture at the level of the apex of the re-entrant angle.

For this purpose, a part made of mineral or composite material has been developed with two contiguous sides defining between them a re-entrant angle.

According to the invention, the two sides belong to the same one-piece part of the part and are connected to each other by a curve replacing a sharp angle. The part also comprises an added element having, on the one hand, an internal portion which fills a space corresponding to the curve and, on the other hand, an external portion defining a sharp edge of the re-entrant angle.

In this way, the curve replaces the sharp re-entrant angle of the two sides, and therefore eliminates the stress concentration zone of the part. The incipient fractures in the material are therefore minimized. The part then has a re-entrant angle made in a single piece, but the apex of the angle is in fact made without a sharp angle, but rather via a curve. The added element includes the sharp corner and thus gives the illusion of a real sharp re-entrant corner cutout of the one-piece part.

The sharp corner may be present in the added element, but its small size relative to that of the part prevents it from presenting the same fragility and the same disadvantages.

According to a first embodiment, the added element is in a single part. Thus the assembly of the added element on the part is easy.

According to a second embodiment, the one-piece part of the part is in the form of a plate and comprises two added drops, each fixed along a side, not parallel to the plate, that is to say inclined or orthogonal with respect to the plate, said added overhangs being in contact with one another and defining between them a sharp edge of the re-entrant angle. Fallout can be used to achieve a part that looks like a thick part, while achieving savings in mass or material cost. The fallout can also be used to create edges on the sides of the re-entrant angle. The two overhangs define between them a sharp edge of the re-entrant angle, which corresponds to the desired aesthetic.

Possibly contact faces between the sides and the fallout are machined and have an assembly profile, such as a bevel or a rabbet, so as to increase their contact surface and guarantee the solidity and aesthetics of their assembly, or offer more favorable assembly possibilities.

Possibly contact faces between the part at the level of the curve and the added element are machined and present an assembly profile for the same reasons.

In this second embodiment, the insert is preferably in two parts each forming an integral part of one of the fallouts, so as to have only three parts to be assembled instead of four.

In either embodiment, the insert may be in the form of a cured resin or glue, or may be made of the same material as the part. If it is resin or hardened glue, the manufacture of the elements of the part is facilitated since it is not necessary to use machines with several axes or numerical control. If it is an element made of the same material as the part, then the visual uniformity of the assembly is guaranteed.

In order to simplify manufacturing, the curve is of the circular, oval or elliptical type and has a radius of between 0.5 and 200 mm.

More specifically, the material is granite, or marble, or glass, or ceramic or even a composite material with or without mineral filler.

The part has an external edge at its inside corner. Preferably, this external edge is machined according to a finishing profile measuring at least 0.5 mm. This not only makes it possible to have a non-cutting edge for the user, but above all to conceal the joint between the one-piece part of the part and the added element.

Advantageously, the finishing profile follows the profile of the curve, so that the one-piece part of the part has absolutely no sharp corners.

There is a perspective view, seen from above, of a part according to one embodiment of the invention.

There is a rear view, of a one-piece tray according to the embodiment of the .

There is a detail view similar to the .

There is another detail view of a part similar to the .

There is a detail view of a fallout.

There is a detail view of a part according to another embodiment.

There is a perspective view, seen from above, of a part according to another embodiment.

There is a perspective view, seen from above, of a part according to another embodiment.

There is a perspective view, seen from above, of a part according to another embodiment.

Detailed description of the invention

There illustrates a part (1) made of mineral material according to the invention, and in the particular case where it is a worktop. The part (1) can be of any shape or application, it can for example be a vertical panel covering a facade, or any other solid object that the designer wishes to create.

In the particular embodiment illustrated , the part (1) is an "L"-shaped worktop having two contiguous sides (2a, 2b), the two sides (2a, 2b) here forming a right re-entrant angle. In this case, the one-piece part (2) is a plate. In the rest of the document, reference will be made to the plate (2) without this limiting the possible embodiments of the one-piece part (2). Thanks to the invention, the work plan is in one piece and has no cutout in the extension of one of the two sides (2a, 2b).

The mineral material can be granite, marble, ceramic or even glass. It can also be a composite material that may or may not include a mineral filler. Composite materials generally consist of a resin ensuring the cohesion of the material, and can be loaded with mineral particles giving the part (1) its appearance, as well as improved mechanical properties.

It is recalled that the invention is not limited to re-entrant angles exclusively as right angles, but to all re-entrant angles, i.e. angles whose measurement on the side of the material is more than 180°.

The sharp re-entrant edges constitute stress concentration zones in the material. These areas weaken the part (1), and it is common for incipient breaks or cracks to occur at this location, degrading the part (1) and possibly leading to its ruin.

Also, the part (1) has, at the junction between the two sides (2a, 2b), a re-entrant curve (4), that is to say on the side of the material. This re-entrant curve (4) connects the two sides (2a, 2b), thus eliminating the sharp edge of the re-entrant corner of the part (1), and thus prevents the aforementioned drawbacks.

This curve (4) can be circular with a constant radius, for example between 0.5 and 200 mm, and preferably 8 mm. A small radius makes it possible to have a curve (4) that is more discreet and thus can be integrated into the chamfer of the edge of the two sides. In the case where the curve (4) is oval or elliptical, its radius varies but its minimum radius is then between 0.5 mm and 200 mm.

In the case where the part (1) is a work plan, it then comprises a tray (2). It can be envisaged to add fallout (5) along each side (2a, 2b).

These fallouts (5) are longitudinal elements attached in a non-parallel manner to the surface of the plate (2), and can be arranged according to two objectives to be achieved.

A first objective is to give the part (1) a much greater visual depth. Preferably, the fallouts are fixed orthogonally, but they can also be fixed at an angle, for example of 30° or even 45°, so as to form an inclined face with respect to the plate (2). However, the use of fallout (5) saves material during the manufacture of the part (1). Its mass is also limited. This solution is particularly indicated in the case of ceramic-type materials, where the thickness of the plates is limited. The thickness of the fallouts (5) is not necessarily equal to that of the plate (2).

A second objective is that the fallouts (5) constitute the edges of the plate (2). Thus, at the nip point, said overhangs (5) are in contact with one another and between them define a sharp edge of the nip point. In this case, the height of the fallouts (5) is generally equal to the thickness of the plate (2). Depending on the desired configuration, the height of the drops (5) can be different from the thickness of the plate (2), for example the drops (5) can protrude slightly from the upper surface of the plate (2), in order to create a zone water retention for example. The thickness of the fallouts (5) is not necessarily equal to that of the plate (2).

The added element (3) can be part of only one of the fallouts (5), or be in two parts each forming an integral part of one of the fallouts (5).

Conventionally, the fallouts (5) are fixed by gluing to the part (1). To this end, it is possible to machine, for example in the form of a bevel, the contact surfaces between the flats (2a, 2b) and the fallouts (5), as illustrated in FIGS. 2 and 3. Without departing from the scope of the invention this machining can take the form of any assembly profile, such as a tab, a rabbet or a molding. The contact surfaces between the drops (5) themselves can also be machined and have an assembly profile.

A finishing profile (8) such as a chamfer or rounding can also be made on the outer edge of the part (1). This finishing profile (8) measuring at least 0.5 mm makes it possible to "break the external angle" of the part (1), which avoids both having a sharp angle which could injure the user; and which makes it possible to reduce the fragility of the external edge during the life of the part (1). This finishing profile (8) also makes it possible to remove the bonding burrs, and possibly to conceal the bonding joint linked to the radius of the curve (4). Also, if bas-relief moldings are present on the overhangs (5), then the moldings are connected to the finishing profile (8) so that there are no discontinuities between them.

At the edge of the re-entrant corner, this finishing profile (8) can be joined in different ways illustrated in Figures 4 and 6:
- either by following the radius of the curve (4) as shown . Thus, the finishing profile (8) has no sharp re-entrant corner. This solution is the safest with respect to the stress concentrations, but can be considered as being a defect in the appearance of the part (1);
- either by including a sharp corner edge as illustrated . The sharp re-entrant corner is present only at the level of the finishing profile (8), that is to say on a limited portion of the part (1). Thus, the stress concentrations remain limited, which does not harm the strength of the part (1), and the aesthetics of the part (1) is improved.

There illustrates that for aesthetic purposes, and in order to give the illusion of a sharp-edged cutout, the re-entrant curve (4) is filled by an added element (3). This added element (3) can be of different natures and of different designs, in a single part or in several parts.

It can first of all be simply a glue or a resin, presenting if possible an appearance similar to the material of the part (1) once hardened. In this way, it is not necessary to first manufacture an additional element, the geometry of which is complex. In this case, it may be judicious to produce a re-entrant curve (4) with a small radius, for example with a radius of 8 mm or less. Thus, the volume to be filled by the glue is limited.

As illustrated in Figures 7, 8 and 9, the insert (3) can also be a kind of key, for example in the shape of a ¾ round. This solution is particularly suitable in cases where the part (1) does not have any fallout and is of limited thickness, for example less than 50mm; as well as in cases where the fallouts (5) are assembled to the top (2) with an assembly profile which is a rebate. It is obvious that even if the profile of the internal portion of the insert (3) must correspond to that of the curve (4), it is not necessarily identical so that a functional clearance allows the assembly of the insert (3), and leaves enough room for glue.

In the case where the part (1) includes fallouts (5), the added element (3) can also be an integral part of only one of the fallouts or of both fallouts (5). It can either be part of only one of the spin-offs (5), or be in two parts, each of which is an integral part of one of the two spin-offs (5).

In the preferred embodiment where part (1):
- comprises a tray (2);
- includes spillovers (5);
- That the contact surfaces between the sides (2a, 2b) and the fallout (5) are bevelled;
- that at the re-entrant curve (4), the contact surfaces between the one-piece part (2) and the insert (3) are also bevelled;
- And that the insert (3) is in two parts each forming part of a fallout (5);
then said fallouts (5) have the form illustrated .

It can be seen there that the fallout (5) comprises a first bevel (6) intended to come to bear against a homologous bevel of a face (2a or 2b) of the part (1); as well as a second bevel (7), of curved shape and similar to that of the re-entrant curve (4), so that the assembly of the two fallouts (5) with the part (1) leaves only a minimum of void between the rooms, which is especially noticeable .

Thanks to the bevels, the contact surfaces between the parts are increased, which allows a better resistance of the assembly by gluing.

We see on the that the presence of the assembly profiles on the plate (2), here bevels, is mainly visible on the underside of the part (1). Logically, in the case of a bevel, for example at 45°, the radius of the bevel on the underside of the plate (2) corresponds to the radius of the re-entrant curve (4) plus the thickness of the plate (2) .

With preferred values of a re-entrant curve (4) with a radius of 8mm, a plate thickness (2) of 12mm and in the case of a 45° bevel, then the radius of the bevel on the underside of the plate ( 2) is 20mm. However, the upper face of the plate (2) has a re-entrant curve (4) of only 8 mm, which does not unduly impact the visual appearance of the re-entrant corner of the part (1) and further promotes the illusion of a sharp re-entrant angle.

There illustrates an embodiment in which there are no fallouts (5). The insert (3) is a key which is housed in the curve (4).

There illustrates an embodiment where the assembly profile between the drops (5) and the plate (2) is a rebate made so that the outer edge of the part (1) is that of the plate (2). The assembly profile between the two fallouts (5) is a bevel. In the illustrated mode, the added element (3) is not integrated with the fallouts (5) and here takes the form of a key, which is assembled by gluing with the plate (2) and the fallouts (5).

There illustrates another embodiment, in which the assembly profile between the overhangs (5) and the top (2) is a rabbet made in the other direction than that shown . Here, the outer edge of the part (1) is that of the fallouts (5) and of the insert (3). In this particular embodiment, the curve (4) is not inward but outward and takes the form of a fillet. However, the assembly between the plate (2), the drops (5) and the added element (3) will give the part (1) the appearance of a sharp angle, without the part (1) not be weakened.

Furthermore, the part (1) can be shaped differently from Figures 1 to 9 without departing from the scope of the invention, which is defined by the claims. In particular, the part (1) can be shaped differently from a worktop, and can be of any type suitable for the present application. The curve (4) can be inward or outward, depending on the assemblies and finishes provided.

In addition, the technical characteristics of the various embodiments and variants mentioned above can be, in whole or for some of them, combined with each other. Thus, the part (1) can be adapted in terms of cost, functionality and performance.

Claims (12)

Part (1) in mineral or composite material having two contiguous sides (2a, 2b) defining between them a re-entrant angle, characterized in that the two sides (2a, 2b) belong to the same one-piece part (2) of the part ( 1), the two sides (2a, 2b) are connected to each other by a curve (4) replacing a sharp re-entrant angle so as to avoid incipient fractures in the material, and in that the part ( 1) comprises an insert (3) having, on the one hand, an internal portion which fills a space corresponding to the curve (4) and, on the other hand, an external portion defining a sharp edge of the re-entrant angle. Part (1) according to Claim 1 , characterized in that the added element (3) is in a single part. Part (1) according to Claim 1, characterized in that the one-piece part (2) is in the form of a plate and the part (1) comprises two added drops (5), each fixed along a side (2a, 2b), and inclined or orthogonal with respect to the plate (2), said added overhangs (5) being in contact with one another and defining between them a sharp edge of the re-entrant angle. Part (1) according to Claim 3 , characterized in that the contact faces between the flats (2a, 2b) and the overhangs (5) are machined and have an assembly profile, such as a bevel or a rabbet. Part (1) according to Claim 1 , characterized in that the contact faces between the part (1) at the level of the curve (4) and the added element (3) are machined and have an assembly profile, such as a bevel or a rabbet. Part (1) according to Claim 3 , characterized in that the added element (3) is in two parts, each forming an integral part of one of the overhangs (5). Part (1) according to Claim 1 , characterized in that the added element (3) is a resin or a hardened adhesive, or is made of the same material as that of the part (1). Part (1) according to Claim 1 , characterized in that the curve (4) is of the circular, oval or elliptical type and has a radius of between 0.5 and 200 mm. Part (1) according to Claim 1 , characterized in that the material is of the mineral type, such as a ceramic. Part (1) according to Claim 1 , characterized in that the material is of the composite type. Part (1) according to Claim 1 , characterized in that it has an outer edge at its inside corner, the outer edge is machined according to a finishing profile (8) measuring at least 0.5 mm. Part (1) according to Claim 11 , characterized in that the finishing profile (8) follows the profile of the curve (4).