Furniture panels of wood-based material clad with sheets of thermodeformable material are known. They comprise a frame with two uprights and two crosspieces joined together, and a closure panel (filler board) retained by said frame within a continuous perimetral groove provided in it.

The frame elements (uprights and crosspieces) and the filler board are all formed of wood-based material (preferably MDF) and are clad with a sheet of thermodeformable material which forms the"upper"cladding, ie the panel outer surface, and the perimetral edging. The"lower"cladding, ie panel inner surface, is generally covered with melamine.

For constructional reasons the upper cladding and the lower cladding cannot be formed as one and the same sheet, consequently the two claddings show a joining line, which generally is made to coincide with the inner perimetral edge of the panel. This joining line constitutes a critical region for the panel, in that in connecting an upright to a crosspiece the joining line of the two elements coincides with the joining line between the upper cladding and the lower cladding of each of these. As this joining line between the two elements also generally acts as a collection region for condensates and those liquids used for periodic panel cleaning, with the passage of time these liquids inevitably infiltrate between the two claddings. It follows that because of the hydrophilic nature of the panel components, these infiltrations result in component swelling, with rapid damage to the panel.

This swelling of the wood-based material of the panel components also occurs at the joining line between the upper cladding and the lower cladding of the filler board and also at the holes provided in the connection regions between an upright and a crosspiece for the insertion of dowels between the two.

An object of the invention is to eliminate or at least reduce this phenomenon by preventing those liquids which inevitably collect preferentially along the joining lines between the panel components from being able to infiltrate into the wood-based material, to quickly subject the panel to irreparable damage.

This and further objects which will be apparent from the ensuing description are attained according to the invention by a wood-based furniture panel clad with thermodeformable sheet material, as described in claim 1.

A preferred embodiment of the invention is described in detail hereinafter with reference to the accompanying drawings, on which : Figure 1 is a front view of a panel of the invention ; Figure 2 is an exploded perspective view of a variant thereof ; Figure 3 is a partly sectional enlarged detailed view of the joining region between an upright, a crosspiece and the corresponding portion of the filler board ; Figure 4 is a partly sectional view on the line IV-IV of Figure 3; and Figure 5 is a partly sectional view on the line V-V of Figure 3.

As can be seen from the figures, the panel of the invention comprises a frame formed from two uprights 2 and two crosspieces 4 assembled such that the two ends of the two crosspieces 4 adhere to the corresponding ends

of the inner side of the two uprights 2, in the"crosspieces inside" configuration.

In the course of the ensuing description reference will be made to this configuration, however a configuration is also possible in which the two ends of the uprights 2 adhere to the corresponding ends of the inner side of the two crosspieces 4 in the"crosspieces outside"configuration.

Along that edge which when the frame is assembled forms the inner edge, both the two uprights 2 and the two crosspieces 4 are provided with a groove 6 for engaging a filler board 8 which completes the panel.

Both the four frame elements 2,4 and the filler board 8 are formed of wood-based material, for example of the type known as MDF, and are clad with a sheet of thermodeformable material. Specifically, each upright 2, each crosspiece 4 and the filler board 8 are clad with two separate sheets 10 and 12, one sheet 10 constituting the so-called upper cladding, which covers the exposed surfaces of each element, ie the outer front surface and the outer and inner edges, the other sheet 12 consitituting the so-called lower cladding, which covers only the hidden surface, ie the inner front surface. The two claddings 10 and 12 are bounded by a joining line 14, which extends along the inner edges of the frame uprights and crosspieces, and along the inner edge of the filler board 8.

With the traditional method for assembling the panel, holes 16 are provided through the mutually contacting surfaces of the uprights 2 and crosspieces 4 to house dowels 18 which connect them together, the dowels then being glued to join the uprights 2 and crosspieces 4 together after the filler board 8 has been interposed between them.

A characteristic which differentiates this invention from the prior art is the provision of an undercut 20 along all the inner edges of the uprights 2 and crosspieces 4 at their junction. To solve the confronted technical problem it would be sufficient for this undercut 20 to be provided on that end portion of the inner edges of the uprights which faces the crosspieces and on the corresponding inner abutting edge of the crosspieces, however production considerations suggest that said undercut 20 be provided along all or part of the perimeter of the uprights and crosspieces.

The purpose of this undercut, visible in detail in Figure 5, is to distance the line of contact 22 between each upright 2 and the crosspiece 4 from the joining line 14 between the outer cladding 10 and the inner cladding 12 of each upright and of each crosspiece. In this manner the condensates and any liquids used to clean the panel, which generally collect in the juncture between the two frame components, are localized in a position distant from the joining line between the outer cladding 10 and the inner cladding 12, so that any infiltration through this joining line 14 into the wood-based material with consequent swelling becomes extremely improbable.

Another important characteristic of the invention is the prolongation of the outer cladding 10 of the filler board 8 to form a perimetral lip 24, which when the filler board is inserted into the groove in the frame folds over to cover the joining line between the outer cladding 10 and the inner cladding 12, so protecting said joining line from possible liquid infiltration into the filler board, while at the same time properly stabilizing the filler board within the frame.

A further important characteristic of the invention is the creation of a recess 26 within that the portion of the upright 2 which faces the end of the

crosspiece 4. The recess 26, preferably formed during the machining operation by which the groove housing the corresponding edge of the filler board 8 is formed in the upright 2, is completely covered by the said sheet 10 of thermodeformable material and involves that upright region surrounding the two holes 16 housing the dowels 18, and is bounded all around by a raised surface 30 on which effective contact is made with the end of the crosspiece 4.

This characteristic prevents any contact between the crosspiece and upright at the dowels 18, so preventing any liquid which wets the panel from being able to infiltrate into the holes 16, and possibly onto the dowels to damage the wood-based material.

The said recess could be provided in the end of the crosspiece 4 instead of in the upright 2, or it could be provided in both. Another important characteristic of the invention is that the outer cladding of each crosspiecelupright continuously covers the inner surface of the groove 6 housing the panel filler board.

This characteristic ensures perfect impermeability of facing surfaces in accidental contact with external liquids (condensate, cleaning water, etc.).

A further important characteristic of the invention is that the groove 6 provided in the crosspieces for the insertion of the transverse edges of the filler board has a portion 32 slightly inclined outwardly downwards. This characteristic enables any liquid entering the groove to be conveyed to its ends, so avoiding contact with the lower edge of the filler board, and preventing flow by capillarity to the upright/crosspiece contact surface.

Another characteristic of the invention is that at the intersection between the groove in the inner edge and that end of the crosspiece in

contact with the upright, the crosspiece cladding forms a tab 34 which is flattened and compressed downwards to hence prolong the inclination of the incline portion and facilitate outflow of any liquid collecte at the ends of the groove.