Patent Description:
Referring by way of example to a furniture item of the bookcase or shelf unit type, it typically comprises two uprights or vertical walls parallel one to the other, between which are interposed one or more horizontal shelves having the function of defining a support and resting 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 type, normally separate from the shelf, such as brackets, screws, pins and the like, which need to be mounted with special tools. This solution is not satisfactory - on the one hand because it makes assembly of the shelf rather laborious, and on the other hand because the means of fixing remain visible.

In order to seek to overcome these disadvantages, shelf-support devices have been proposed consisting of an elastic pin that is inserted into an edge of the shelf and has a protruding part that engages in a corresponding seat in a wall of the furniture item, under the action of a spring. The pin is normally protruding from the device, through the action of the spring and, when the shelf is assembled, it interferes with the vertical wall of the furniture item, returning into the device to snap out of it when it finds itself opposite the appropriate seat formed in the wall of the furniture item. To disassemble the shelf, a special tool must be used on the device, through an opening formed in the shelf, to cause the pin to retract against the action of the spring.

The international patent application <CIT>, not yet published, describes a device of this type in which a cam element is provided, which can be actuated with an appropriate key, for moving the pin between two positions of maximum and minimum extraction from the casing of the device, in which positions of maximum and minimum extraction it is free to spring in order to completely re-enter said casing under the action of an external thrust.

A device entirely similar in terms of functioning to the one just described is known from <CIT>.

These devices, although technically valid, have the disadvantage of requiring a special key for actuation of the cam, in order to move the pin between the positions of maximum and minimum extraction, an operation necessary both during the phase of assembly of the shelf and of possible removal of the same.

It is also necessary to form at least one hole in the shelf in order to access the seat of manoeuvre of the cam.

<CIT> (<CIT>) describes a device for supporting shelves of furniture, housed in a seat provided in the shelf, comprising a casing inside of which is housed a containment body in which is inserted a pin moving axially in contrast to the action of a spring. The containment body is sliding along a slanting guide provided in the casing in such a way as to move obliquely with respect to the axis of the pin in order to pass from a deeper position to a less deep position, and vice versa, in the seat of the shelf, causing, respectively, a progressive extraction and a progressive re-entry of the pin.

A major disadvantage of this solution is that the spring, acting between the pin and the containment body, does not have any effect on the sliding of the latter which, among other things, needs to be brought manually into the "armed" position, shown for example in <FIG> of the patent, before the mounting of the shelf.

The object of the invention is to overcome the disadvantages mentioned above.

More particularly, an object of the present invention is to provide a device for supporting and fixing shelves of furniture that does not require any tools for assembling and disassembling the shelf.

Another object of the invention is to provide such a device that is completely invisible and therefore does not require the forming of holes in the visible parts of the shelf, so as to optimise the aesthetic value of the furniture item.

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

A further object of the present invention is to provide such a device that guarantees a stable fixing of the shelf.

Last but not least, it is an object of the invention to provide such a device configured in such a way that the elastic means provided therewith always keep it in an armed position for the mounting of the shelf.

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

According to the invention, a device is provided for supporting and removably fixing shelves of furniture, such as bookcases, shelf units and the like, by means of a pin associated with a shelf and configured to be inserted in a hole formed in a side wall of an item of furniture, said device being configured to be inserted in the thickness of the shelf and comprising a casing, substantially flattened parallelepiped in shape, housing a carriage inside of which said pin terminating with a head is mounted, which is stressed by a compression spring, to protrude normally from the casing and so as to be able to re-enter completely into the casing with a linear displacement following a force exerted axially thereon, wherein said pin has a body sliding linearly in the carriage, without substantial transversal play, whereon at least one slanting plane is provided, co-operating with a corresponding slanting plane provided on the casing to cause a transversal sliding of the carriage, in a direction perpendicular to the axis of the pin, simultaneously to an oblique movement of the pin through the action of said spring or following a transverse force acting on the same with consequent exiting or re-entry, at least partial, of the pin in the casing.

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 following detailed description in which reference is made to the accompanying drawings which represent preferred and non-limiting embodiments thereof and wherein:.

Referring to <FIG>, a description is given of the first embodiment of the device for supporting and fixing furniture shelves according to the present invention, denoted overall by reference numeral <NUM>. It comprises an outer casing <NUM> of a substantially flattened parallelepiped shape, inside whereof a pin <NUM> is mounted, terminating with an ogive or hemispherical head <NUM>, which is stressed by a compression spring <NUM>.

Naturally, the head <NUM> of the pin can have a different conformation from the ogive one, it being in any case preferable that it is rounded in order to have an easier sliding against the corresponding vertical wall of the furniture item, when it interferes with it during the insertion and the extraction of a shelf, as will be mentioned here below.

The flattened shape of the casing <NUM> allows the device <NUM> to be able to be inserted into a correspondingly shaped hole formed in the thickness of a shelf <NUM> of a furniture item <NUM> (<FIG>) with the front surface of the casing <NUM> flush with the edge of the shelf, and the pin <NUM> protruding therefrom to be inserted in a hole <NUM> formed in a corresponding vertical wall <NUM> of the furniture item, as will be described in greater detail below.

The casing <NUM> is made in two half-shells, a lower half-shell or base <NUM> and an upper half-shell or lid <NUM> which, joined one to the other, determine the aforementioned flattened hollow parallelepiped conformation closed at one end <NUM> which is arranged in the thickness of the shelf <NUM> and open at the opposite end <NUM>, from which the pin <NUM> protrudes.

The casing <NUM> may optionally be provided, at a section of the open end <NUM>, with a collar <NUM> having the function of defining a stop element when it is introduced in said hole of the shelf.

The casing <NUM> is preferably made in plastic material or nylon or in another known equivalent material suitable for the purpose, not excluding metallic material, while the pin <NUM> is in metal or hard plastic. The spring <NUM> is conveniently metallic.

Referring now more particularly to the blown-up views of <FIG> and <FIG>, the mounting of pin <NUM> in casing <NUM> and the movement thereof during functioning of the device is illustrated.

The pin <NUM> protrudes at the front from a body <NUM>, suitably shaped, also made in metal or hard plastic, sliding linearly along the axis of the pin <NUM> in a support frame <NUM>, which will also be referred to as carriage in that provided with a transversal sliding, i.e. perpendicular, with respect to the axis of the pin <NUM>, as will be seen here below.

The carriage <NUM>, which has the shape of a rectangular frame, has two opposed side walls <NUM>, <NUM>, a rear wall <NUM> and a front wall <NUM> determining a seat <NUM> suitable for receiving, substantially without transversal play, the body <NUM> of the pin <NUM>, with the spring <NUM> acting between said rear wall <NUM> and the body <NUM>.

More particularly, according to the embodiment illustrated in the drawings, the spring <NUM> is partially housed in a cavity <NUM> formed in the body <NUM> and accommodates, on the opposite side, a stem <NUM> protruding from the rear wall <NUM> of the carriage <NUM>.

Naturally, what is disclosed is purely by way of an example, it being possible to insert the spring <NUM> in a stem protruding at the rear from the body <NUM> and optionally act directly against the rear wall <NUM> of the carriage <NUM>.

The front wall <NUM> of the carriage <NUM> has a window <NUM>, which in the drawing is shown open above, but which could also be closed, for the passage of the pin <NUM>.

For the transversal sliding of the carriage <NUM>, its rear wall <NUM> has an upper projection <NUM>' and a lower projection <NUM>" suitable for being housed, respectively, in a guide rail <NUM> provided inside the upper half-shell <NUM> and in an opposed guide rail <NUM> formed in the lower half-shell <NUM>. A further guide rail <NUM> is provided in the lower half-shell <NUM>, in proximity of the front wall <NUM>, suitable for housing a pair of feet <NUM> protruding below from the side walls <NUM>, <NUM> of the carriage <NUM>.

The two half-shells <NUM>, <NUM> are assembled together, by means of screws <NUM>, to form the shell <NUM>, in which the carriage <NUM> slides transversally.

The transversal sliding of the carriage <NUM> in the shell <NUM> is determined by at least one pair of slanting planes provided, respectively, on the body <NUM> of the pin <NUM> and on one of the two half-shells <NUM>, <NUM>.

In the example shown in the drawings, merely for easier visualization, a slanting plane provided on the upper half-shell <NUM>, denoted by reference numeral <NUM>, is constituted by the oblique side of a window <NUM>, substantially in the form of a rectangular trapezium/pentagon, formed in this half-shell.

It is however clear that the slanting plane <NUM> can be formed internally to the half-shell <NUM>, which is moreover preferable, providing a simple protrusion that constitutes the slanting plane <NUM>, or a recess in the thickness of the wall of the half-shell, which substantially reproduces the outline of the window <NUM>.

A specular slanting plane could optionally be provided on the lower half-shell <NUM>.

The body <NUM> of the pin <NUM> is shaped so as to present in its upper part a slanting plane, constituted by a small vertical wall <NUM>, having the same slant as the slanting plane <NUM> so as to be able to slide thereon.

Naturally, a similar slanting plane will be provided in the lower part of the body <NUM> should a corresponding slanting plane be also provided on the lower half-shell.

With the structure of the device <NUM> described above, an axial thrust exerted on the pin <NUM> causes complete retraction thereof in the housing <NUM> in contrast to the action of the spring <NUM>, by linear sliding of the body <NUM> in the rectangular seat <NUM> of the carriage <NUM>, as illustrated in <FIG>, to which further reference will be briefly made here below.

At the cessation of the thrust exerted on the pin <NUM>, the action of the spring <NUM> causes exiting thereof from the casing <NUM>, as shown in <FIG>.

Instead, a transverse force exerted on the pin <NUM> causes a sliding of the slanting plane <NUM> provided on the body <NUM> against the homologous slanting plane <NUM> provided on the shell <NUM>, with consequent transversal displacement of the carriage <NUM> wherein the body <NUM> is housed without substantial transversal play. At the same time, the pin <NUM> returns to the casing <NUM>, as shown in <FIG>, where the transverse force that acts on the pin is to be understood in the opposite direction to that indicated by the arrows shown therein.

In this embodiment, the length of the slanting plane <NUM> provided on the half-shell <NUM> is such as to determine a stroke of the carriage <NUM> such as to cause the complete retraction of the pin <NUM> in the casing <NUM>, including the ogive head <NUM>, as shown in <FIG>.

When the transverse force exerted on the pin <NUM> ceases, the action of the spring <NUM> tends to return the pin <NUM> into the extracted position and therefore the carriage <NUM> into the starting position.

From what has been disclosed, the functioning of the device <NUM> in the phase of assembly and disassembly of a shelf <NUM> appears clear, which is however now briefly illustrated with reference to <FIG> and <FIG>.

<FIG> schematically show the steps of assembly of the shelf <NUM> which is provided with two pairs of devices <NUM> at two of its opposite sides.

In <FIG> the pins <NUM> of the devices <NUM> provided on the left side of the shelf <NUM> have been inserted in the corresponding holes <NUM> formed in the corresponding vertical wall <NUM> of the furniture item <NUM>, and the shelf is tilted upwards.

The following <FIG> show the shelf that is lowered, as indicated by the arrows, bringing the pins <NUM> of the corresponding devices <NUM> into interference with the right vertical wall of the furniture item, along which they slide backwards, until coming into alignment with the corresponding holes <NUM> into which they snap under the action of the spring <NUM> (<FIG>).

The backward movement and subsequent exit of the pin <NUM> from the casing <NUM> are shown in <FIG>, which correspond to the steps of assembly shown in <FIG>.

<FIG> show the steps of disassembly of the shelf, which is pulled horizontally towards the exterior as indicated by the arrows. The transverse force exerted on each pin <NUM> by the edge of the corresponding hole <NUM> in which it is housed, during the extraction of the shelf, is obviously opposite to the direction indicated by the arrows, and in this opposite direction the carriage <NUM> will move through the action of the slanting planes, until causing the complete re-entry of the pin <NUM> with its ogive head <NUM> in the shelf <NUM> and subsequent exit through action of the spring <NUM> when the shelf has been extracted (<FIG>).

<FIG> show the movement of the carriage <NUM> from the position of maximum extraction of the pin <NUM> (<FIG>) corresponding to the condition of assembled shelf of <FIG>, up to the completely retracted position in the casing <NUM> (<FIG>) corresponding to the condition wherein the pin has come out from the respective hole <NUM> and abuts against the wall <NUM> of the furniture item as shown in <FIG>. With the shelf (<FIG>) completely extracted, the spring <NUM> causes the exiting of the pin and the simultaneous translation of the carriage <NUM>, which moves into the position shown, for example, in <FIG>.

It should be noted that the positions of the carriage <NUM> shown in <FIG> correspond to an extraction of the shelf in the opposite direction to that shown in <FIG>.

From what has been disclosed, the advantages of the invention, which allows rapid assembly and disassembly of shelves of furniture, without having to use tools of any kind and without having to form any holes in the visible parts of the shelves, as is necessary with similar devices of the prior art, are clear.

Referring now to <FIG>, a second embodiment of the invention is briefly described using the same reference numerals of the previous embodiment to distinguish identical or corresponding parts.

The device <NUM> of this second embodiment is practically identical to that of the first embodiment, from which it is distinguished by a shorter length of the slanting plane <NUM> provided on the upper half-shell <NUM>.

Therefore, a detailed description of the device, to which all the considerations previously made apply in full, will be omitted, with only an illustration of the different function that can be attributed to the shorter length of the abovementioned slanting plane <NUM>, the effect of which is to determine a shorter stroke of the carriage <NUM> and not to completely retract the pin <NUM> into the casing <NUM> when a transverse force is exerted on the pin in the phase of removal of the shelf.

Therefore, the steps of assembly of the shelf, shown in <FIG>, and the corresponding positions of the pin <NUM>, shown in <FIG>a to <NUM>'a, are identical to the corresponding steps of assembly of the first embodiment.

In the phase of extraction of the shelf, pulling it horizontally towards the exterior, the latter remains locked in the position of <FIG>, at the end of the stroke of the carriage <NUM>, due to interference of the ogive head <NUM> of the pin <NUM> protruding from the casing <NUM> (<FIG>) in the corresponding hole <NUM>.

At this point, in order to be able to completely retract the pin <NUM> into the casing <NUM> and remove the shelf <NUM>, it is sufficient to exert a vertical force thereon, for example upwards, as shown in <FIG>, <FIG>, sliding the head <NUM> against the edge of the corresponding hole <NUM> formed in the wall of the furniture item.

The incomplete retraction of the pin <NUM> in the casing <NUM> during the extraction of the shelf may be useful to prevent the shelf from falling under the action of its own weight when the pins exit from the corresponding holes.

<FIG>, <FIG>, <FIG>, <FIG>, <FIG> illustrate a third embodiment of the invention, which will be described in brief using again the same reference numerals to distinguish identical or corresponding parts.

The device <NUM> is substantially the same as that of the previous embodiments, except for a different conformation of the head <NUM> of the pin <NUM>, which still maintains a rounded shape, but is enlarged with respect to the pin, so as to determine an internal collar <NUM>'.

In addition, a bushing <NUM> is provided, which partially reproduces the profile of the casing <NUM> and which is placed in a slotted hole, with horizontal orientation, provided in the side wall <NUM> of the furniture item.

The bushing <NUM> has a cradle conformation presenting, at one end (which will be referred to as rear with reference to the direction of insertion of the shelf), a substantially semicylindrical seat <NUM> with a front shoulder <NUM>, which is arranged flush with the wall <NUM>.

At the other (front) end of the bushing <NUM> a vertical slanting plane <NUM> is provided, oriented towards the interior of the bushing.

According to this embodiment, the assembly of the shelf <NUM>, once arranged with the devices <NUM> provided therein in vertical alignment with the corresponding bushings inserted in the side walls of the furniture item, is carried out by lowering it so that the head <NUM> of each pin <NUM> is compressed against the wall <NUM> until it clicks into the corresponding bushing <NUM>, as shown in <FIG> and <FIG>b.

Subsequently the shelf <NUM> is pushed horizontally as indicated by the arrow in <FIG> and the head <NUM> of the pin <NUM> enters the seat <NUM> of the bushing as shown in <FIG>b.

Continuing to push the shelf <NUM> as indicated by the arrow in <FIG>, the interference of the head <NUM> of the pin <NUM> against the edge of the seat <NUM> causes the movement of the carriage <NUM> through sliding of the slanting plane <NUM> provided on the body <NUM> of the pin against the slanting plane <NUM> on the casing <NUM>, with consequent retraction of the head <NUM>, whose collar <NUM>' stably engages with the shoulder <NUM>, as shown in <FIG>b.

The disassembly of the shelf takes place by extracting it horizontally in the opposite direction to that of insertion, as shown by the arrows in <FIG>.

Initially the head <NUM> comes out from the casing <NUM> through the action of the spring <NUM>, disengaging itself from the shoulder <NUM> (<FIG>).

Subsequently, the head <NUM> comes out from the seat <NUM> and rests on the slanting plane <NUM> of the bushing, sliding on the same and starting to retract into the casing <NUM> (<FIG>) until it is completely retracted (<FIG>) to allow the extraction of the shelf.

Claim 1:
Device (<NUM>) for supporting and removably fixing furniture shelves, such as bookcases, shelf units, and the like, by means of a pin (<NUM>) associated with a shelf (<NUM>) and configured to be inserted in a hole (<NUM>) formed in a side wall (<NUM>) of a piece of furniture (<NUM>), said device (<NUM>) being configured to be inserted in the thickness of the shelf (<NUM>) and comprising a casing (<NUM>), substantially flattened parallelepiped in shape, housing a carriage (<NUM>) inside of which said pin (<NUM>) terminating with a head (<NUM>) is mounted, which is stressed by a compression spring (<NUM>), to protrude normally from the casing and so as to be able to re-enter completely into the casing with a linear displacement following a force exerted axially thereon,
characterised in that said pin (<NUM>) has a body (<NUM>) sliding linearly in the carriage (<NUM>), without substantial transversal play, whereon at least one slanting plane (<NUM>) is provided, co-operating with a corresponding slanting plane (<NUM>) provided on the casing (<NUM>) to cause a transversal sliding of the carriage (<NUM>), in a direction perpendicular to the axis of the pin, simultaneously to an oblique movement of the pin (<NUM>) through the action of said spring or following a transverse force acting on the same with consequent exiting or re-entry, at least partial, of the pin in the casing.