WO2013109799A1

WO2013109799A1 - Dishwashing machine with movable basket holder device

Info

Publication number: WO2013109799A1
Application number: PCT/US2013/022008
Authority: WO
Inventors: Riccardo DONATI; Riccardo ORLANDI
Original assignee: Premark Feg L.L.C.
Priority date: 2012-01-20
Filing date: 2013-01-18
Publication date: 2013-07-25
Also published as: ITTO20120039A1

Abstract

A dishwashing machine (1) including a tank on which a basket holder device is positioned, including: a shelf (9) made such as a flat grid (47) provided with a pair of vertical side rails (12, 44), a first side rail (12) being obtained in one piece with the grid and including a pair of pins (11) arranged parallel to a first side of the tank; and a pair of rotation seats (14) for the pins, adapted to snappingly receive the pins to rotationally hinge the shelf (9) upwards with respect to the tank, obtained close to the tank and integral with a casing (2) of the dishwashing machine; each seat includes: a metal bracket (16); a block (21) made of synthetic plastic material fitted onto the bracket, shaped so as to delimit a semi-cylindrical recess (22) at the top; and a bolt (23) fitted through the block and the bracket; the shelf having, internally, a pair of fixed feet (37) to rest on the tank and a rotating prop (40) for blocking it in rotated position.

Description

DISHWASHING MACHINE WITH MOVABLE BASKET HOLDER DEVICE

TECHNICAL FIELD

The present invention relates to a professional dishwashing machine, of the type in which the washing chamber is defined by a tank and by a hood which moves vertically with respect to the tank to allow a dish holder basket to be positioned on, and removed from the tank, which in use is enclosed in the hood, which is sealingly resting on the tank.

BACKGROUND ART

Such a type of dishwashing machine is known, e.g., from US-A-4536043. To support the dish holder basket in position above the tank, these dishwashing machines are provided with a basket holder device, which also guides the basket during the positioning and removal operations, which usually occur by horizontal sliding from and towards tables or conveyors, with which the dishwashing machine usually forms a washing line. The known basket holder devices consist of a simple frame, resting on the tank and intended to receive and guide a pair of lateral edges of the basket.

Although satisfactory, this type of basket holder device has the drawback of hindering the tank cleaning operations, and in particular the ones of the filter arranged on the drain pipe and positioned on the bottom of the tank, in particular if it is provided with one or more intermediate cross members to allow, if needed, directly resting particularly cumbersome dishes, such as pots or pans, on the basket holder frame. To resolve such a problem, the frame of known basket holder devices is fitted so as to be removable from the dishwashing machine, so as to "uncover" the tank. However, once removed, the frame is a cumbersome element, which is difficult to stock.

DISCLOSURE OF INVENTION

It is the object of the present invention to provide a dishwashing machine for professional use of the type described, which overcomes the drawbacks detailed above, which is equipped with a movable basket holder device, but which should not necessarily be removed to easily access the tank. It is another object of the invention that the movable basket holder device be reliable while being easy to make and assemble and absolutely safe for the operators, without any sharp surfaces.

Therefore, according to the invention a dishwashing machine for professional use is provided, as defined in claim 1.

In particular, the dishwashing machine according to the invention comprises a supporting casing, a tank made on at least part of a horizontal panel carried at a lower part by the casing, a hood carried in a vertically sliding manner by the casing over the tank, so as to selectively take a first position, in which the hood defines a washing chamber with the tank, and a second position in which the hood is away from the tank to allow access to the tank; and a basket holder device arranged immediately over the tank to receive in use a dish holder basket which, in the first position of the hood, remains enclosed in the washing chamber; the basket holder device comprising a shelf and support means of the shelf over the tank.

According to a feature of the invention, the support means of the shelf comprise: at least one pair of pins carried by a first side rail of the shelf which rail is integrally obtained in one piece with the shelf and is adapted in use to laterally guide the dish holder basket onto the shelf, which pins are arranged coaxial to each other and parallel to a first side of the tank; and at least one pair of rotation seats for the pins obtained close to the tank and integral with the casing, adapted to snappingly receive the pins to rotationally hinge the shelf upwards with respect to the tank, about an axis parallel to the first side of the tank and defined by the pins, so that the shelf may selectively take a first position, in which it is arranged immediately over the tank, substantially parallel to a bottom wall thereof, and a second position in which it is rotated upwards away from the tank to uncover the tank and form with the tank a relatively wide, predetermined angle.

Thereby, the tank is simply and quickly accessible, without any need to completely remove the shelf, which may in any event be removed if needed, such as in traditional machines, the pins only being snappingly inserted in the rotation seats.

In order to make rotation seats that operate reliably, adapted to last over time, and safe for the user, each rotation seat for the pins comprises: a metal bracket integrally restrained to the casing and comprising at least one pair of facing walls spaced apart from each other, arranged perpendicular to the first side of the tank, on an upper edge of each of said facing walls, a semicircular indent being obtained; a block made of synthetic plastic material fitted onto the bracket and shaped, on the plane of the facing walls of the bracket, such as an asymmetric U, so as to delimit a semi-cylindrical recess at the top adapted to snappingly receive a respective pin; and a bolt fitted through the plastic material block and the facing walls of the bracket, parallel to the recess and immediately under the same .

Lastly, the support means of the shelf also comprise a pair of fixed feet arranged under the shelf, on the side opposite to the first side rail, and a rotating prop to block the shelf in the second position, rotated upwards and away from the tank; thereby the user's hands are kept free for the cleaning operations, as there is no need to support the shelf in rotated position. Furthermore, the shelf is preferably made such as a crossed mesh grid, with the first side rail being obtained in one piece with the grid, the latter and the first side rail consisting of a plurality of metal rods welded to a rectangular frame, and possibly to each other. A second side rail for guiding the dish holder basket is carried by the frame in a removable manner, so as to be arranged either parallel and at side opposite to the first side rail, or adjacent and perpendicular to the first side rail, so that the dishwashing machine may supply both rectilinear washing lines and those arranged at an angle.

BRIEF DESCRIPTION OF THE DRAWINGS

Further objects and advantages of the invention will become more apparent from the following description of a non- limiting embodiment thereof, provided by way of mere example and with reference to the figures in the accompanying drawings, in which:

figure 1 diagrammatically shows a perspective view of a dishwashing machine made according to the invention, with parts removed for better comprehension;

figure 2 shows the same view in figure 1 of the dishwashing machine according to the invention, in a different position of use, in particular during tank cleaning operations, again with parts removed for better comprehension;

figures 3 and 4 show respective perspective views on enlarged scale, of a same detail of the dishwashing machine in figure 1, in use configuration and in exploded configuration, respectively; and figures 5 and 6 show, on a different scale, the basket holder shelf of the dishwashing machine in figures 1 and 2, and a detail thereof, respectively.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to figures 1 to 6, numeral 1 indicates, as a whole, a dishwashing machine for professional use, of the so-called "hood" type.

With particular reference to figures 1 and 2, numeral 1 indicates, as a whole, a dishwashing machine (1), which hereinafter, for the sake of brevity, shall simply be referred to as "dishwasher" 1, comprising a supporting casing 2, a tank 3 made on at least part of a horizontal panel 4 carried at a lower part of casing 2, and a hood 5, known and for simplicity only shown diagrammatically and indicated with a broken line in figure 1, carried in a vertically sliding manner by casing 2 in known way, over tank 3, so as to selectively take a first position, which is the one diagrammatically shown and indicated with a broken line in figure 1, in which hood 5 defines a washing chamber 6 with tank 3, and a second position (not shown), in which hood 5 is away from tank 3 to allow tank 3 to be accessed.

Dishwasher 1 further comprises a basket holder device 7 arranged immediately over tank 3 to receive in use a dish holder basket 8, of known type (figure 1) which, in the first position of hood 5, remains enclosed in the washing chamber 6.

The basket holder device 7 comprises a shelf 9 and support means 10 of the shelf 9 over tank 3.

According to one aspect of the invention, the support means 10 comprise at least one pair of pins 11 carried by a vertical first side rail 12 of shelf 9 which rail is integrally obtained in one piece with shelf 9 and is adapted in use to laterally guide the dish holder basket 8 onto shelf 9 in known way. The pins 11 are arranged coaxial to each other and parallel to a first side 13 of the tank. The support means 10 further comprise at least one pair of rotation seats 14 for the pins 11 obtained close to tank 3, integral with casing 2.

The seats 14, which are well illustrated in figures 3 and 4, are adapted to snappingly receive the pins 11 to rotationally hinge shelf 9 upwards with respect to tank 3, about an axis A (figure 2) parallel to side 13 of tank 3 and defined by the pins 11, so that shelf 9 may selectively take a first position, shown in figure 1, in which it is arranged immediately over tank 3, substantially parallel to a bottom wall 15 thereof, so as to house in use basket 8, and a second position (figure 2), in which shelf 9 is rotated upwards away from tank 3, to uncover tank 3, and forms with tank 3 a relatively wide, predetermined angle, selected so as to allow an operator easy access to tank 3 and in particular, the bottom wall 15, for maintenance and cleaning operations. As shown in figures 3 and 4, each rotation seat 14 for the pins 11 comprises a metal bracket 16 (figure 4) integrally restrained to casing 2 and comprising at least one pair of facing walls 17 spaced apart from each other in the longitudinal direction of development of side 13, and arranged perpendicular to side 13 of the tank.

According to the non-limiting embodiment disclosed, side 13 is the rear side of tank 3, which is arranged towards a vertical rear panel 18 of casing 2, which overhangingly extends perpendicular and upwards with respect to panel 4 and which serves to support, in known way, the vertical sliding of hood 5. Tank 3 is generally parallelepiped in shape and is generally delimited by rectilinear lines, but side 13 may be of any shape, and in most known dishwashers, has a protuberance at the center line which is inserted into tank 3 and which serves to create the space required to support panel 4 of a rotating spray arm, which is known, and is removed from figures 1 and 2 and therefore not shown, which remains in use under basket 8.

A semicircular indent 20 is obtained on an upper edge 19 of each of the walls 17; a block 21 made by moulding a synthetic plastic material compatible with the relatively aggressive environment of the washing chamber 6, e.g. polyamide, is fitted onto each bracket 16 and is shaped, on the plane of the facing walls 17 of bracket 16, such as an asymmetric U, so as to delimit a semi-cylindrical asymmetric recess 22 at the top adapted to snappingly receive a respective pin 11 (figure 3) , with the possibility of guided rotation substantially without any clearances about axis A of pin 11 (since block 21 is elastically deformable, recess 22 may be dimensioned so as to also house pin 11 with slight interference or in any event with such a clearance so as to be negligible and to achieve a shaft-base or hole-free base coupling, or indifferent); lastly, in addition to bracket 16 and a respective block 21, each rotation seat 14 comprises a bolt 23 (formed by a screw and a nut, shown in exploded configuration in figure 4) fitted through the plastic material block 21 and the facing walls 17 of bracket 16, parallel to recess 22 and immediately under the same, which in use makes block 21 integral with bracket 16.

According to the preferred embodiment disclosed, each bracket 16 is made by means of a metal sheared, bent flat plate comprising a central portion 24 of flat rectangular shape from which three wings overhangingly extend, which were folded as an L outside the laying plane of the central portion; two first opposite wings define the facing walls 17, and a third wing 25, is folded at 90° against the two first wings (walls) 17, so that bracket 16 defines a half box-like structure, the first two wings 17 of which define two lateral walls arranged perpendicularly to the central portion 24, which is welded to casing 2, preferably to the supporting panel 18 of hood 5 arranged parallel to the rear side 13 of tank 3.

The upper edge 19 of each of the facing walls 17 defined by the first wings is shaped, in the laying plane of the first wings, i.e. of the walls 17, such as an L vertically arranged and facing tank 3 (figure 4), thus providing the walls 17 an asymmetric L shape in the laying plane thereof; the semicircular indent 20 is obtained on the portion of edge 19 of each wall 17 defining the short side of such an L; in a position underneath indent 20, each of the walls 17 is provided with a through hole 26 adapted to receive (the screw of) bolt 23.

The semicircular indent 20 of each of the walls 17 is further dimensioned so as to be adapted to receive, if needed, a respective pin 11 of shelf 9 resting thereon with a clearance. Thereby, if one of the blocks 21 breaks, it is possible to remove both the blocks 21 and directly rest the pins 11 inside the dents 20 thus maintaining the possibility of rotating shelf 9 about axis A, even if in this case the pins 11 are no longer perfectly guided in rotation, substantially without clearances, such as when they instead engaged recess 22.

Each synthetic plastic material block 21 is shaped so as to completely cover the respective bracket 16, once fitted thereon, by snappingly engaging on at least the pair of walls 17 with respective opposite lateral walls 27 provided with respective through holes 28 (only one of which is shown in figure 4) adapted to receive (the screw of) bolt 23; the upper semi-cylindrical recess 22 of block 21 is obtained between the lateral walls 27, parallel to bolt 23, and is delimited by first and second longitudinal rear 29 and front 30 edges, respectively, of block 21, arranged parallel to edge 13 of tank 3, edge 30 being lower than edge 29 and being arranged towards tank 3.

Furthermore, the upper semi-cylindrical recess 22 of block 21 is shaped so that, when block 21 is fitted onto the bracket, at least a bottom portion of a lateral wall 31 of recess 22 can rest on bolt 23, block 21 being shaped so as to be internally hollow, except for the suitable stiffening ribs, which are not shown for simplicity; recess 22 is further internally provided, on a lateral outer surface 32 of the lateral wall 31 (hence inside recess 22) and close to the edges 29 and 30, with a pair elastically deformable projections 33 and 34 adapted to engage pin 11 each time it is introduced into recess 22 to counter any coming out thereof in radial direction.

The pair of pins 11 is integrally obtained in one piece with the side rail 12 so that the pins 11 laterally protrude outwards with respect to shelf 9, because the pins 11 are laterally obtained so as to protrude with respect to the side rail 12, that is so as to protrude towards panel 18, and parallel to side rail 12, which is generally rectilinear; in particular, the pins 11 are obtained at respective opposite ends 35 (only one of which is shown in figure 3) of an upper longitudinal edge 36 of the side rail 12, hence arranged at the top of shelf 9 and parallel to a laying plane of shelf 9, which is generally flat and rectangular in shape. This is in order to facilitate the rotation of shelf 9 about axis A without interferences.

Again for this purpose, the support means 10 of shelf 9 further comprise a pair of fixed feet 37 (figures 2 and 5) arranged under shelf 9 so as to vertically and overhangingly protrude from the same, under shelf 9, and integrally obtained with shelf 9, on the side opposite to the side rail 12. This is arranged parallel to the rear side of shelf 9, closer to panel 18 and, therefore, the feet 37 are carried by a front side 38 of shelf 9.

The feet 37 are adapted to abuttingly rest against the horizontal panel 4 in which the tank is obtained and/or against a perimetral edge 39 of tank 3 (depending on the related dimensions of tank 3 and of panel 4) when shelf 9 is arranged in the first position.

According to one aspect of the invention, the support means 10 of shelf 9 further comprise a rotating prop 40 to block shelf 9 in the second position in figure 2, rotated upwards and away from tank 3.

Prop 40 is preferably made such as a leg 41 having a first L-folded end (42) which overhangingly extends from shelf 9, adapted to abuttingly rest against the horizontal panel 4 and/or against the perimetral edge 39 when shelf 9 is arranged in the second position; a second end 43 of leg 41, opposite to end 42, is hinged and restrained to shelf 9, laterally with respect to the side rail 12, so that leg 41 is rotatable with respect to shelf 9 about an axis B parallel to the pins 11 (figure 5) .

Furthermore, leg 41 is dimensioned and, accordingly, end 42 of leg 41 is shaped, so that the first end 42 of leg 41 is adapted to snappingly engage the side rail 12 when leg 41 is rotated to a position parallel to shelf 9, so as to block the rotation of leg 41 with respect to shelf 9 when shelf 9 is in the first position.

According to a further aspect of the invention, shelf 9 comprises a second side rail 44, which is vertical and is smaller in size than the side rail 12 and is restrained to shelf 9 in a removable manner, preferably by means of screws 45, so as to be selectively arranged on the side opposite to the side rail 12 and parallel thereto, i.e. along side 38, such as in the accompanying figures, or in a position adjacent to the side rail 12, perpendicular thereto, i.e. along one of two opposite sides 46 of shelf 9 perpendicular to side 38; for this purpose, the length of the side rail 44 is smaller than side 38 and at most, equal to the length of the sides 46.

According to a last aspect of the invention, shelf 9 is made such as a crossed mesh grid 47 (figure 5) , the first side rail 12 is obtained in one piece with grid 47, and the latter and the side rail 12 consist of a plurality of metal rods 48 welded to a rectangular frame 49, and possibly to each other; frame 49 consists in turn of a pair of folded rods 50 to form a closed ring and arranged over each other, at a predetermined distance and between which the opposite ends of at least the rods 48 forming the grid 47 are inserted .

The pins 11 are defined by respective opposite portions of rod 50 which delimits the upper edge 36 of the side rail 12; such opposite portions of this rod 50, which form the ends 35, are substantially U-folded, in such a direction as to move away from shelf 9, and each form a sort of bracket which overhangingly protrudes from grid 47 and towards panel 18.

The rail side 44 (which is well illustrated in plan view from above in figure 6) also comprises at least one metal rod 51 conveniently bent and provided with at least two feet 52, which are inserted in the space between the pair of rods 50 which form frame 49; the feet 52 are fixed to frame 49 in a removable manner by screws 45, due to a pair of internally threaded respective washers 53 which can be coupled with screws 45 and adapted to be sandwiched, by means of screws 45, against the pair of rods 50 forming frame 49, or by means of other releasable means, again by direct tightening on frame 49. Lastly, grid 47 is optionally provided along one of the sides 46 thereof with a slide 54 to facilitate the positioning of basket 8 on shelf 9.

Claims

1. A dishwashing machine (1) of the type comprising a supporting casing (2), a tank (3) made on at least part of a horizontal panel (4) carried at a lower part of the casing, a hood (5) carried in a vertically sliding manner by the casing over the tank, so as to selectively take a first position, in which the hood defines a washing chamber (6) with the tank, and a second position in which the hood is away from the tank to allow the tank to be accessed; and a basket holder device (7) arranged immediately over the tank to receive in use a dish holder basket (8) which, in the first position of the hood, remains enclosed in the washing chamber; the basket holder device comprising a shelf (9) and support means (10) of the shelf over the tank; characterized in that the support means of the shelf comprise: at least one pair of pins (11) carried by a first side rail (12) of the shelf (9) which rail is integrally obtained in one piece with the shelf and is adapted in use to laterally guide the dish holder basket onto the shelf, which pins (11) are arranged coaxial to each other and parallel to a first side (13) of the tank; and at least one pair of rotation seats (14) for the pins obtained close to the tank (3) and integral with the casing (2), adapted to snappingly receive the pins (11) to rotationally hinge the shelf (9) upwards with respect to the tank, about an axis (A) parallel to the first side of the tank and defined by said pins, so that the shelf (9) may selectively take a first position, in which it is arranged immediately over the tank, substantially parallel to a bottom wall (15) thereof, and a second position in which it is rotated upwards away from the tank to uncover the tank and forms with the tank a relatively wide, predetermined angle.

2. A dishwashing machine according to claim 1, characterized in that each rotation seat (14) for the pins comprises: a metal bracket (16) integrally restrained to the casing (2) and comprising at least one pair of facing walls (17) spaced apart from each other, arranged perpendicular to the first side of the tank, an indent (20) of semicircular shape being obtained on an upper edge (19) of each of said facing walls; a block (21) made of synthetic plastic material fitted onto the bracket (16) and shaped, in the plane of the walls facing the bracket, as an asymmetric U, so as to delimit a semi-cylindrical recess (22) at the top, adapted to snappingly receive a respective pin (11); and a bolt (23) fitted through the plastic material block (21) and the facing walls (17) of the bracket, parallel to the recess (22) and immediately under the same.

3. A dishwashing machine according to claim 2, characterized in that each bracket (16) is made by means of a sheared, bent flat plate comprising a central portion (24) of flat rectangular shape from which three wings overhangingly extend, which were folded as an L outside the laying plane of the central portion, two first opposite wings to define said facing walls (17), and a third wing (25), folded at 90° against the two first wings, so that the bracket defines a half box-like structure, the first two wings (17) of which define two lateral walls arranged perpendicularly to the central portion (24), which is welded to the casing, preferably to a supporting panel (18) of the hood arranged parallel to a rear side (13) of the tank defining said first side thereof; said upper edge (19) of each of the facing walls (17) defined by the first wings being shaped, in the laying plane of the first wings, as an L vertically arranged and facing the tank, said semicircular indent (20) being obtained on the edge portion (19) of each wall defining the short side of the L; and, in a position underneath said indent (20), each of the facing walls defined by the first wings being provided with a through hole (26) adapted to receive said bolt; the semi-circular indent (20) of each of the facing walls being dimensioned so as to receive, if needed, a respective pin (11) of the shelf resting thereon with a clearance.

4. A dishwashing machine according to claim 2 or 3, characterized in that each said block (21) made of synthetic plastic material is shaped so as to completely cover a respective bracket (16), once fitted thereon, by snappingly engaging at least said pair of facing walls (17) of the bracket with respective opposite lateral walls (27) thereof provided with respective through holes (28) adapted to receive said bolt; said upper semi-cylindrical recess (22) of the block being obtained between said opposite lateral walls (27) of the block, parallel to said bolt and being delimited by first (29) and second (30) longitudinal edges of the block, arranged parallel to the first side of the tank, the second edge (30) being lower than the first (29) and being arranged towards the tank (3) .

5. A dishwashing machine according to claim 4, characterized in that said upper semi-cylindrical recess (22) of the block is shaped so that, when the block (21) is fitted on the bracket, at least one bottom portion of a lateral wall (31) of the semi-cylindrical recess can rest on the bolt (23), the block (21) being internally hollow; the semi- cylindrical recess (22) being internally provided, on a lateral outer surface (32) of said lateral wall (31) and close to said first and second longitudinal edges (28,30), with a pair of elastically deformable projections (33,34) adapted to engage a said pin (11) .

6. A dishwashing machine according to one of the preceding claims, characterized in that said at least one pair of pins (11) is integrally obtained in one piece with the first side rail (12) so that the pins laterally protrude outwards with respect to the shelf (9), said pins being laterally obtained so as to protrude with respect to said first side rail (12) and parallel thereto, at respective opposite ends (35) of an upper longitudinal edge (36) of the side rail, arranged over the shelf and parallel to a laying plane of the shelf (9) .

7. A dishwashing machine according to claim 6, characterized in that said support means (10) of the shelf further comprise a pair of fixed feet (37) arranged under the shelf so as to vertically and overhangingly protrude from the same, under the shelf (9) and integrally obtained with the shelf, on the side opposite to the first side rail (12), which feet are adapted to abuttingly rest against said horizontal panel (4) in which the tank is obtained and/or against a perimetral edge (39) of the tank when the shelf is arranged in the first position; and a rotating prop (40) to block the shelf in the second position, rotated upwards and away from the tank; the prop (40) being preferably made as a leg (41) having a first L-folded end (42) which overhangingly extends from the shelf, adapted to abuttingly rest against said horizontal panel in which the tank is obtained and/or against the perimetral edge of the tank when the shelf is arranged in the second position; and a second end (43) , opposite to the first, hinged and restrained to the shelf (9), laterally to said first side rail (12), so that the leg (41) is rotatable with respect to the shelf about an axis (B) parallel to said pins.

8. A dishwashing machine according to claim 7, characterized in that the leg (41) is dimensioned and said first end (42) of the leg is shaped so that the first end of the leg is adapted to snappingly engage said first side rail (12) when the leg is rotated to a position parallel to the shelf, so as to block the rotation of the leg with respect to the shelf when the shelf is in the first position.

9. A dishwashing machine according to any one of the preceding claims, characterized in that the shelf (9) comprises a second side rail (44), which is smaller in size than the first side rail (12) and is restrained to the shelf in a removable manner, preferably by means of screws (45) , so as to be selectively arranged on the side opposite to the first side rail (12), parallel thereto and in a position adjacent to the first side rail, perpendicular thereto.

10. A dishwashing machine according to any one of the preceding claims, characterized in that the shelf (9) is made as a crossed mesh grid (47), the first side rail (12) being obtained in one piece with the grid (47), the latter and the first side rail consisting of a plurality of metal rods (48) welded to a rectangular frame (49), and possibly to each other, the frame (49) consisting in turn of a pair of folded rods (50) to form a closed ring and arranged over each other, at a predetermined distance and between which the opposite ends of at least the rods (48) which form said grid are inserted; said at least one pair of pins (11) being defined by respective opposite portions of a rod delimiting an upper edge (36) of the first side rail (12) and substantially U- folded, in such a direction to move away from the shelf.

11. A dishwashing machine according to claim 10, characterized in that the shelf (9) comprises a second side rail (44) restrained in a removable manner to the shelf; the second side rail (44) comprising at least one metal rod (51) appropriately folded and provided with at least two feet

(52), which are inserted into the space between the pair of rods (50) forming said frame; at least one pair of screws

(45) ; and pairs of respective washers (53) which may be coupled to said screws and adapted to be sandwiched, by means of said screws, against the pair of rods (50) forming said frame from opposite sides thereof.