Patent Description:
Referring by way of example to a furniture item of the bookcase type or to a shelf unit, it typically comprises two uprights, or vertical walls, or sides parallel and opposed one to the other, between which are interposed one or more horizontal shelves having the function of defining a resting and support surface for books, magazines, vases and/or other multiple and different objects.

The shelves are arranged and fixed between the vertical walls using means of various types, normally separate from the shelf, such as brackets, screws, pins and the like, which need to be fitted with special tools. This solution is not satisfactory, on the one hand because it makes assembly of the shelf somewhat laborious, and on the other hand because the fixing means remain visible.

Recently, in order to seek to overcome these disadvantages and to avoid the use of tools, technology has provided new solutions for shelf-support devices consisting of an elastic pin that is inserted in an edge of the shelf and having a protruding part that engages in a corresponding seat formed on a side of the furniture item, under the action of a spring. The pin is normally protruding from the device, due to the action of the spring, and when the shelf is assembled, it interferes with the side of the furniture item, retracting into the device to snap out of it when it is opposite the special seat formed in the side of the furniture item. While no tools are required to assemble the shelf, its disassembly requires the use of a special tool on the device, so as to make the pin recede from the seat in the side.

In addition to the disadvantage of having to use tools in order to remove the shelf from the furniture item, it has to be underlined that a second opening in the shelf (usually a hole placed below the shelf at the height of the elastic pin) is required, through it is possible to access the device in order to cause the pin to retract against the action of the spring.

<CIT> describes a support device for shelves of furniture items comprising a pin designed to be arranged inside a shelf and movable axially against the action of elastic means between a position recessed in the shelf and a position protruding therefrom to engage in a hole provided in a side of the furniture item, wherein said pin has a tip terminating in an inclined plane.

<CIT> discloses a device for supporting a removable panel with respect to a wall of an article of furniture comprising a hollow body with a cavity having a cross-sectional circular shape with a flat side, wherein a movable element having the same cross-sectional shape can only slide axially between a first operating position, wherein the movable element is projecting from the hollow body, and a second operating position, wherein the movable element is contained in the hollow body. A main elastic means is provided to move the movable element towards the first operating position and at least one return elastic means to return the movable element from the first operating position to the second operating position along a longitudinal direction, overcoming the force of the main elastic means when the panel is removed from the wall of the article of furniture.

The object of the present invention is to overcome the abovementioned disadvantages. More particularly, an object of the present invention is to provide a device for supporting and fixing furniture shelves which does not need tools for mounting and/or removing the shelf from the furniture item.

A further object of the invention is to provide such a device that does not need different openings on the shelf other than the one for mounting the device itself, such that it is made substantially completely hidden from view so as to optimise the aesthetic merit of the furniture item.

A further object of the invention is to provide such a device that allows easy and rapid assembly and disassembly of the shelf.

Yet another object of the invention is to provide such a device that is simple and inexpensive to manufacture.

These and other objects are achieved by the device of the invention that has the features set forth in claim <NUM>.

According to the invention, a device is provided for supporting and fixing shelves to the sides of furniture items, such as bookcases, shelf units and the like, configured to be inserted in the edge of a shelf to engage with a side of the furniture item, said device comprising a casing of substantially cylindrical shape with an internal cavity having a front opening, inside of which housing is mounted a pin which is stressed by elastic means, with a tip of the pin normally protruding from the edge of the casing under the action of said elastic means, wherein said inner cavity of the casing has at least partially an elongated cross sectional shape like the shape of said front opening, with flat opposing side walls, such as to house the pin loosely in a plane parallel to said flat opposing side walls which have longitudinal recesses designed to accommodate corresponding raised parts provided on the pin, in such a way that the pin is restrained locked in the casing with the tip protruding therefrom, propelled by said elastic means, and in such a way that a force opposing the action of said elastic means causes the pin to retract in the casing with a tilting action in a plane parallel to said flat opposing side walls of said cavity with elongated cross sectional shape.

Advantageous embodiments of the invention are disclosed by the dependent claims.

The constructional and functional features of the device for supporting and fixing shelves of the present invention will be made clearer by the detailed description that follows in which reference is made to the accompanying drawings that show a preferred and non-limiting embodiment thereof, and in which:.

<FIG> schematically shows a portion of furniture item <NUM>, comprising a shelf <NUM>, mounted between two vertical side walls or sides <NUM> by means of four supporting and fixing devices <NUM> according to the invention, two of which are made visible in the drawing.

Referring to <FIG>, the device <NUM> comprises an outer body or casing <NUM> with a substantially hollow cylindrical shape, inside whereof is mounted a pin <NUM> that is stressed by a compression spring <NUM>. A helicoidal spring is shown in the drawings, but any elastic element is contemplated by the invention.

The device <NUM> is housed in a hole <NUM> formed in the thickness of the shelf <NUM> with the front surface of the casing <NUM> practically flush with the edge of the shelf, and the pin <NUM> protruding therefrom to be inserted in a hole <NUM> formed in the side <NUM> of the furniture item, as shown, for example, in <FIG> and as will be described in greater detail here below.

Advantageously, the casing <NUM> has an annular expansion or collar <NUM> at the front that abuts against the edge of the shelf <NUM> to determine an end of stroke condition during the phase of inserting the device in the hole <NUM>.

In shelf <NUM>, apart from hole <NUM>, no other machining processes are provided, either on the upper or on the lower one, which improves the overall aesthetics.

The casing <NUM> is of the tubular type, open at both ends, and has an inner cavity <NUM> suitably shaped to accommodate the pin <NUM> with the possibility of sliding and tilting, as will be described in greater detail here below.

The pin <NUM> is substantially cylindrical in shape and has a front section or tip <NUM> that can protrude at least partially in front of the casing <NUM> to be inserted in the hole <NUM> formed in the side of the furniture item, and terminating with a bevelled, tapered end <NUM>. Behind the tip <NUM>, at the two sides of the pin <NUM>, respective raised parts <NUM> of a substantially rectangular shape are provided, which develop in the axial direction of the pin <NUM> and terminate at the front with a rounded ogival end <NUM>, joined to the base of the rectangular raised part with a concave profile section <NUM>.

Correspondingly, the inner cavity <NUM> of the casing <NUM> has on its opposing side walls <NUM> (one of which is shown in <FIG>) a pair of side recesses <NUM>, designed to accommodate with longitudinal sliding the raised parts <NUM> of the pin <NUM>. The width or height of the recesses <NUM> tends to decrease in the front part with an upward convex profile section <NUM> terminating with a rounded end with substantially semi-circular profile <NUM>, designed to accommodate the rounded ogival end <NUM> of the raised parts <NUM> of pin <NUM>, while the concave section <NUM> of the raised parts matches perfectly with the convex section <NUM> of the recesses.

Thanks to coupling parts, the pin <NUM> remains restrained in the casing <NUM> even when the tip <NUM> is fully withdrawn, under the action of the elastic means <NUM>, which act between a rear seat <NUM> formed in the casing <NUM> and the rear part of the pin <NUM>.

More particularly, to the rear of the pin <NUM> a cylindrical protrusion <NUM>, of a smaller diameter than the pin, is provided in such a way that it is possible to insert it in the helicoidal spring <NUM> and, on the other side, the seat <NUM> has a circular profile, of a smaller diameter than that of the spring, which develops for an arc of approximately <NUM>° terminating with two opposing fins <NUM> with which the terminal coils of the spring <NUM> go to engage, which thus remains embedded in the seat <NUM>.

Naturally, that which is shown in the drawings is only an example of a way of fixing the end of the spring, as many other solutions are possible. For example, the housing <NUM> could be of such a diameter as to accommodate the spring, and be closed at the rear, completely or partially, by a wall flush with the rear end of the casing <NUM>.

As can be seen in particular in <FIG> and <FIG>, the front opening <NUM> of the casing <NUM> has an elongated, substantially elliptical shape with a vertical axis, with parallel opposing sides, in order to allow the tilting of the pin <NUM>, which has a diameter smaller than the vertical dimension in which said front opening <NUM> is elongated and is normally arranged in its upper part. Consequently, the cavity <NUM>, which substantially reproduces the shape of the front opening <NUM>, has substantially flat opposing side walls <NUM>, in which the aforementioned recesses <NUM> are formed, and houses the pin <NUM> loosely in a vertical plane, i.e. in a plane parallel to said opposing side walls <NUM>.

Referring to <FIG>, the device <NUM> can be observed mounted and in its function of supporting the shelf <NUM>.

Having indicated with "r" the main axis of the pin <NUM>, coaxial with its tip <NUM>, and with "s" the axis of the seat <NUM>, apt to accommodate the elastic element <NUM>, it can be observed that they are not coincident one with the other, but parallel and offset. This is an advantageous condition for the positioning of the elastic element <NUM> in that it allows three substantial advantages to be had.

The first advantage is to simplify the equipment for moulding of the casing <NUM> in that in order to make both the recesses <NUM> and the seat <NUM> there is no need for movements inside the mould which would complicate the making thereof and limit the number of possible impressions.

The second advantage is one of simplification during assembly with the insertion of the pin <NUM> along the "r" axis from the rear of the casing <NUM> without additional movements apt to override the seat <NUM> of the spring.

The third advantage is functional in that in the unhooking/hooking phases of the shelf <NUM>, when the pin <NUM> retracts into the casing <NUM>, the pin-spring combination has reduced overall dimensions along the "r" axis in that this axis is not engaged by the spring <NUM> thus allowing a less bulky product in length to be made with all the advantages that this entails, since the installer does not have to drill deep holes in the shelf <NUM>.

Aside from the advantages listed above, the device <NUM> has the same functioning even if the axes "r" and "s" are coincident.

Referring to <FIG>, it is illustrated how the device <NUM> supports the shelf <NUM>.

The shelf <NUM> exerts a load, both through its own weight and what it supports, which load is distributed over the various shelf supports <NUM>. Having indicated, therefore, by "W" the share of the load that the shelf transmits to the individual shelf support, the pin <NUM> will receive a reaction "R" undergoing a rotation "β" with respect to the casing <NUM>, which is contrasted by the simultaneous action between the cylindrical portion of the pin <NUM> with the inner cavity <NUM> of the casing <NUM> and by the reciprocal action of the rounded ends <NUM>, <NUM>, of the raised parts <NUM> and of the recesses <NUM> respectively, effectively preventing the movement of the pin <NUM> with respect to the casing <NUM> and consequently performing the function of supporting the shelf <NUM>.

The behaviour just described instead does not occur in the opposite condition, i.e. when shelf <NUM> is lifted, and therefore an action contrary to the direction of "W" is exerted, as illustrated in <FIG>.

The shelf <NUM> under the action of the force "A" opposite in direction to "W" finds the reaction of the rounded end <NUM> of the raised parts <NUM> of the pin <NUM> on the convex profile section <NUM> of the recesses <NUM> of the casing <NUM>. Initially, the pin <NUM> will be axial to the hole <NUM> formed in the side <NUM> of the furniture item, but when the guide offered by the hole <NUM> is lacking, it will be arranged as illustrated, receding, upon the persistence of the action of the force "A", inside the casing <NUM> with a sliding of the rounded ends <NUM> on the convex profiles <NUM> and consequent tilting of the pin <NUM>, which is permitted by the vertically elongated shape of the front opening <NUM>, and in general of the inner cavity <NUM> of the casing <NUM>.

At the continuation of the action of the force "A", with reference to <FIG>, the tip <NUM> will be in direct contact, with its end <NUM>, with the wall of the side <NUM> of the furniture item. Therefore, in the final phases the recess will terminate with the direct contact of the end <NUM> on the wall itself.

The inverse phase, i.e. of insertion of the shelf <NUM> in the furniture item <NUM>, sees the pin <NUM> banally being completely retracted inside the casing <NUM> by interference with the side <NUM>, until arriving at the hole <NUM> present in the side <NUM> in which the pin <NUM> will have the possibility of being inserted, pushed by the elastic element <NUM>.

It should be noted that the assembly of the shelf <NUM> can take place irrespectively either by sliding the tip <NUM> of the pin <NUM> against the side <NUM> of the furniture item with an action from the top downwards, which is exactly the reverse of the sequence shown in <FIG>, or conversely, with an action from the bottom upwards, which is, moreover, facilitated by the bevelled end <NUM> of the tip <NUM>.

The device described hitherto fully fulfils the functions listed in the introduction to this description. To complete it, in order to fulfil certain needs that may arise in use, it may be required that the shelf does not disengage from its seat, for example as a result of incorrect manoeuvres or in the case of movement of the furniture item, even should it be overturned.

The embodiment variant shown in <FIG> achieves this object by providing a calibrated interference between the casing <NUM> and the pin <NUM>.

More particularly, in the example shown, on the inner side walls of the casing <NUM>, in proximity of its front opening <NUM>, a pair of opposing ribs <NUM> are provided which are specifically housed in corresponding longitudinal grooves <NUM> formed on the pin <NUM>. This interaction does not constrain the axial sliding of the pin <NUM> and therefore its insertion in the hole <NUM> of the side <NUM> of the furniture item (assembly phase), but hinders the phase of tilting of the pin <NUM> inside the casing <NUM>, effectively preventing the unhooking of the shelf except as a result of an upward thrust, as indicated by arrow "A" in <FIG>, which requires a force far greater than the weight "W" of the shelf (<FIG>), a manoeuvre that is necessary to allow pin <NUM> to overcome the obstacle offered by ribs <NUM>.

<FIG>, <FIG> show a further variant on the solution proposed in <FIG>.

In this case, the engagement of the pin <NUM> with the casing <NUM>, in order to avoid unintentional disengagement, is obtained by providing, on the inner side walls of the casing <NUM>, in proximity of its frontal opening <NUM>, a pair of opposing ribs <NUM>, free from the rest of the casing <NUM> by means of appropriate longitudinal slots <NUM>' and circumferential slots <NUM>" partially enveloping the pin <NUM>, but for a good part of its diameter.

The housing that the ribs <NUM> create for the pin <NUM> is such that the pin <NUM> can slide there axially, but its transverse movement of unhooking is prevented, which can only take place if an external force overcomes the elasticity of the ribs <NUM>.

It is possible to calibrate the flexibility of the ribs <NUM> during the phase of construction of the moulding equipment, lengthening or shortening the length of the slots <NUM>', and therefore distancing the circumferential slot <NUM>" more or less from the front edge of the casing <NUM>, in order to make the ribs <NUM> more elastic or more rigid, respectively, in such a way as to restrain the pin <NUM> and consequently the shelf when the furniture item is turned over, respectively more or less.

For the sake of completeness, it should be noted that the grooves indicated with reference numeral <NUM> in <FIG> and <FIG> are slight ribs, intended to improve the fixing of the device in the hole formed in the shelf.

These ribs <NUM> are also present in the embodiments previously described, even if not shown.

From what has been disclosed, the advantages of the invention appear clear, which enables rapid assembly and disassembly of the shelves of furniture items, without the aid of tools and without leaving parts visible.

Claim 1:
Device (<NUM>) for supporting and fixing shelves (<NUM>) to the sides (<NUM>) of furniture items (<NUM>), such as bookcases, shelf units and the like, configured to be inserted in the edge of a shelf (<NUM>) to engage with a side (<NUM>) of the furniture item, said device comprising a casing (<NUM>) of a substantially cylindrical shape with an inner cavity (<NUM>) having a front opening (<NUM>), inside of which housing a pin (<NUM>) is mounted which is stressed by elastic means (<NUM>), with a tip (<NUM>) of the pin (<NUM>) normally protruding from the edge of the casing (<NUM>) under the action of said elastic means, characterised in that said inner cavity (<NUM>) of the casing (<NUM>) has at least partially an elongated cross sectional shape like the shape of said front opening (<NUM>), with flat opposing side walls (<NUM>), such as to house loosely the pin (<NUM>) in a plane parallel to said flat opposing side walls (<NUM>), which have longitudinal recesses (<NUM>) apt to accommodate corresponding raised parts (<NUM>) provided on the pin (<NUM>), in such a way that the pin is restrained locked in the casing (<NUM>) with the tip (<NUM>) protruding therefrom, pushed by said elastic means (<NUM>), and in such a way that a force contrary to the action of said elastic means (<NUM>) causes a backward movement of the pin (<NUM>) in the casing with a tilting action in a plane parallel to said flat opposing side walls (<NUM>) of said cavity with elongated cross sectional shape (<NUM>).