Patent Description:
Generally, the furniture resting against the ground are provided with levelling devices formed by adjustable feet so as to improve the stability thereof and make the shelves thereof perfectly horizontal despite the unevenness of the surfaces on which they rest. These feet are schematically formed by a hollow portion housed in the furniture and a movable portion which can be adjusted so as to slide inside and with respect to said hollow portion to allow the levelling of the furniture.

An example of a foot like the one exemplified is described in patent <CIT> or in patent <CIT>, in which the aforementioned movable portion can be adjusted by means of a screw-and-nut mechanism. The screw of the mechanism comprises a crown head which can be driven in rotation by means of a pinion element. Both the pinion element and the screw and nut screw are housed in a housing element in turn inserted into a seat obtained in the thickness of a shoulder of a furniture to be adjusted. In particular, the screw and the pinion are directly engaged to each other and to the housing element so as to eliminate the clearances of the relative kinematic chain which drives the aforementioned movable portion in motion with respect to the hollow one, that is the housing element.

This would advantageously allow to avoid the collar of the head of the screw in the seat obtained inside the housing element, according to the prior art. As a matter of fact, with the tendency to reduce the thicknesses of the walls of the furniture, even the feet and the components thereof, as a result, tend to decrease in thickness; therefore, even the aforementioned collar and the relative seat are reduced in thickness. However, this reduction would be to the detriment of the robustness and the kinematic transmission described above.

Though it seeks to overcome the problem relating to the improvement of the kinematic chain and the relative robustness, the foot described above does not allow to substantially increase the loads that can be borne with respect to the prior art. As a matter of fact, when the loads increase, the gears between the crown gear of the screw and pinion are subjected to significant forces which tend to ruin them, given the small dimensions required by the aforementioned decrease in thicknesses of the walls of the furniture.

The main task of the subject matter of the present invention is to overcome the drawbacks of the prior art by providing a foot provided with technical solutions capable of overcoming the load of the gears.

The task and the objects outlined above, as well as others which will be more apparent hereinafter, are achieved by an adjustable foot for furniture as defined in claim <NUM>.

Therefore, a first object of the invention is an adjustable foot provided with greater load performance than the known feet.

A second object is a foot that is easy to construct and equally easy to fit and adjust once fitted.

Advantages, characteristics and other objects of the invention will be apparent from the following description, provided by way of non-limiting example, with reference to the attached figures, wherein:.

With reference to <FIG>, the foot of the invention is generally indicated with reference numeral <NUM>. The foot <NUM> comprises a shell <NUM> for covering the mechanism for moving the foot formed by a screw <NUM> adjustably coupled to a nut screw <NUM> and by a pinion <NUM> for actuating the screw. The nut screw <NUM> comprises a widened portion <NUM> for the direct or indirect support on the floor.

In particular, the foot <NUM> is characterised by a housing <NUM> of the pinion adapted to contain the pinion <NUM> inside the bottom of the shell <NUM> so as to be interposed between these two elements. In other words, the pinion <NUM> is not directly engaged with the shell <NUM>, but only with the screw <NUM>, by interposing an element specifically designed to allow to increase the robustness of the engagement of the gears between pinion and screw.

The shell <NUM> is internally hollow body extended on a rectilinear axis X-X coinciding with the rectilinear axis of the foot. As shown in <FIG>, the shell <NUM> is advantageously formed by a single folded metal sheet preferably to form a cylinder with a first end <NUM> open and provided with a flange <NUM>, and a second end <NUM> provided with a through axial hole <NUM> delimited by an axially folded edge 23A. Alternatively, with a suitable processing, the aforementioned hole <NUM> could be substantially closed by the edge 23A thereof. In particular, the two folded edges of the metal sheet are in contact along a shaped longitudinal slot <NUM>.

Starting from the second end <NUM>, the slot <NUM> comprises a first generally rectilinear segment preferably followed by a first radial aperture 25A determined by the widening of said slot by removing the material of the metal sheet, then a second radial aperture <NUM> partially covered by a first plastically deformable tab <NUM>, and lastly at least one shape coupling fitting <NUM> adapted to lock the folding of the metal sheet in position. Preferably, there are two fittings. It should be observed that although optional, the first aperture has the advantage of extending the stem of the pinion <NUM> and optimise the guide of the pinion with the support <NUM> carrying chamfers and axial clearances out of the seat.

Furthermore, at least one second plastically deformable tab <NUM> is then obtained beside said slot <NUM>; preferably, there are two tabs in a diametrically opposite position and preferably at <NUM>° from the slot.

As shown in <FIG>, two notches 21A and 22A are present respectively on the edge 23A and on the flange <NUM> on the diametrically side with respect to the slot <NUM>. These notches allow to fold the metal sheet to form the shell <NUM>.

It should be observed that, according to an advantage of the present invention, in a position diametrically opposite to the first aperture 25A, the metal sheet of the shell <NUM> comprises a corresponding window 25B (<FIG>). Preferably, this window 25B comprises a tooth 25C projecting on the plane thereof preferably on the side closest to the second end <NUM> of the shell <NUM>, so as to act as locking means against the accidental exit of the pinion <NUM> once fitted in operative position.

The great advantage of the shell <NUM> provided by a folded metal sheet lies in the ease of manufacture which can be obtained by cutting and subsequently folding and deforming a sheet web.

Alternatively, although not preferred, the shell <NUM> may be obtained according to the prior art such as for example a single excavated solid workpiece or two half-shells joined together. In any case, irrespective of the technique used, the shell <NUM> must have a window 25B on the side wall in proximity of the second end <NUM> with size such to allow the insertion of the head of the pinion <NUM> orthogonally with respect to the axis X-X. As a matter of fact, as explained in greater detail below, providing such wide aperture and the housing <NUM> of the pinion allows to increase the robustness performance of the foot adjustment gear mechanism.

The housing <NUM> of the pinion <NUM> (<FIG>) is formed by a generally cylindrical block with main axis Y-Y which extends between a first base <NUM> and a second base <NUM> opposite to the first. Furthermore, it is passed through by a through hole <NUM> with a generally circular cross-section which extends with an axis Z-Z transversal with respect to said main axis Y-Y opening on the side wall <NUM> of the housing with two diametrically opposite apertures (<FIG>). A first aperture <NUM> has dimensions such to allow the head of the pinion <NUM> to pass through and a second aperture <NUM> (<FIG>) instead has dimensions such to allow the stem of the pinion to pass through. As a matter of fact, the hole <NUM> is advantageously conformed in a first portion <NUM> which partially reproduces the shape of the head of the pinion and a second portion <NUM> which fittingly reproduces the stem of the pinion. An annular step <NUM> connects the two first <NUM> and second <NUM> portions (<FIG>). It should be borne in mind that there lacks the part of the first portion <NUM> of the hole <NUM> facing toward the second base <NUM>, but there is only present the step <NUM> so that on one side the pinion does not protrude from the first aperture 25A and on the other side the gears of the pinion are entirely free to engage the gears of the head of the screw, as explained hereinafter.

The first base <NUM> is flat and it can optionally comprise a protrusion <NUM> for engagement with the hole <NUM> of the second end <NUM> of the shell <NUM>, should said hole be present, so as to facilitate an automated assembly of the housing in the shell.

The second base <NUM> is instead rounded so as to fully adapt to the upper face of the head of the screw <NUM>, as explained hereinafter, without interfering with the pinion/screw gears.

The pinion <NUM> is a per se conventional member in known levelling devices and it comprises a head <NUM> connected as a single piece with a stem <NUM> through a collar <NUM> so as to have a longitudinal axis A-A (<FIG>). Both the head and the stem are generally cylindrical-shaped and the head <NUM> comprises several teeth <NUM> arranged in an orderly manner on a circular crown <NUM> so as to circumscribe an engagement seat (not shown) for a tool for driving the pinion in rotation.

It should be observed that providing the aforementioned housing <NUM> of the pinion and the broad window 25B of the shell allow the teeth <NUM> to have a greater extension in the direction longitudinal to the axis A-A. In other words, said pinion <NUM> comprises teeth <NUM> which partially occupy the overall dimensions of the thickness of the shell <NUM> (<FIG>).

This greater extension advantageously increases the surface for engagement with the corresponding teeth of the head of the screw and, therefore, the stability during the movement of the gears with the result of increasing the robustness and the duration of the work thereof.

The screw <NUM> is also a member for transmitting the movement present in the other known levelling devices. It extends along a longitudinal axis coinciding with the axis X-X of the shell, when assembled therein. In particular, it comprises a head <NUM> with a crown gear <NUM> such to fittingly mesh with the teeth <NUM> of the pinion <NUM> and a threaded stem <NUM> externally connected to the crown through an annular step <NUM>. The crown <NUM> then circumscribes a seat <NUM> (<FIG>) for housing the second rounded base <NUM> of the housing <NUM> of the pinion <NUM>. It should be observed that also the teeth of the crown <NUM> have dimensions greater than the teeth of the crowns of the screws according to the prior art, specifically due to the fact that they are engaged with the corresponding teeth <NUM> of the pinion, which - as advantageously explained - are oversized with respect to those of pinions normally used. Obviously, the diameter of the head <NUM> shall not exceed the inner diameter of the shell.

The nut screw <NUM> is entirely conventional and it is formed by a body <NUM> which extends rectilinear along an axis coinciding with the axis X-X of the shell when fitted therein. The body is internally hollow, cylindrical and passed through by a threading adapted to be engaged with the threaded stem <NUM> of the screw <NUM>. Furthermore, it is provided with a first perforated end <NUM> and provided with a flange <NUM> and a second end <NUM> for inserting the screw <NUM>. The outer wall of the body <NUM> is also passed through by two longitudinal grooves <NUM> for engagement with the second tabs <NUM> of the shell <NUM> to lock the shell on the nut screw against undesired rotations. Preferably, at the flange <NUM>, the inner wall of the body <NUM> comprises at least one seat <NUM> for engagement with the anti-rotation elements of a possible plate for resting on the ground, as described below. The seat is for example a space delimited by two ribs (not indicated in <FIG>).

As a matter of fact, the flange <NUM> of the nut screw <NUM> may directly rest on a floor or it may rest on a plate <NUM> having the function of widening the base for resting on the floor, therefore stabilising the furniture onto which the foot of the invention is applied, and/or the function of protecting the flange. In addition, the plate may have an aesthetic function given that it may be made with any shapes, sizes, materials and/or colours as desired. In particular, the plate comprises a first generally flat face <NUM> for resting on the floor and a second face <NUM> opposite to the first and provided with anti-rotation elements <NUM> adapted to engage the at least one seat <NUM> of the inner wall of the body <NUM> of the nut screw <NUM>. Preferably, these elements are teeth which engage said seat by interference. Furthermore, the plate <NUM> is provided with a perimeter edge <NUM> raised toward the second face <NUM> so as to define an annular seat (not indicated) for housing the flange <NUM> of the nut screw <NUM>.

According to a preferred embodiment of the invention, the foot <NUM> comprises a sheet <NUM> (<FIG>) for engagement with a flange <NUM> of the shell <NUM>. As a matter of fact, the sheet is particularly advantageous given that the shape of the flange <NUM> of the shell <NUM> could be difficult to calibrate, resulting from the forming of a metal sheet folded on itself. Therefore, the addition of a sheet which corrects/increases the thickness and the radial extension of the flange, allows to ensure a better resting surface of the side of the furniture so as to freely and precisely manage such surface. In particular, the sheet <NUM> is substantially flat with a central hole <NUM>, a first face <NUM> opposite a second face <NUM> and a perimeter edge <NUM> which extends toward said second face. Two locking wings <NUM>, diametrically opposite with respect to the central hole, then extend from the perimeter edge.

With reference to the <FIG>, <FIG>, now described below is the fitting and the operation of the foot <NUM> according to the present invention.

Generally, first and foremost the screw <NUM> is engaged with the nut screw <NUM>, at least for a certain portion of the respective threads. If present, the plate <NUM> is inserted into the hole of the first end <NUM> of the nut screw <NUM> lodging the respective teeth <NUM> in the appropriate seats <NUM> of said first end. At this point, the housing <NUM> of the pinion <NUM> is inserted into the shell <NUM>, previously cut from a metal sheet with the shape described above and folded on itself so as to perfectly match the respective contact edges which form the aforementioned slot <NUM>. In particular, the housing is inserted with the first face <NUM> of the hole <NUM> thereof facing toward the second aperture 25B of the shell and, as a result, the second face <NUM> is faced toward the first aperture 25A of the shell. Furthermore, the first base <NUM> is faced toward the shell (<FIG>).

The housing <NUM> slides in the shell <NUM> until the aforementioned faces are at the apertures of the shell. Now, the pinion <NUM> can be inserted into the second aperture 25B of the shell <NUM> on the side of the stem <NUM> until the latter engages the second portion <NUM> of the hole <NUM> for housing the pinion and the collar <NUM> abuts against the step <NUM> of said hole (<FIG>). It should be observed that the head <NUM> of the pinion <NUM> is internal with a part of the teeth <NUM> that occupies a part of the thickness of the wall of the shell <NUM>, and the stem <NUM> which also occupies a part of the thickness of the wall of the shell.

The screw/nut screw <NUM>,<NUM> is subsequently inserted into the shell <NUM> until the seat <NUM> delimited by the crown gear <NUM> of the head <NUM> of the screw <NUM> rests against the second base <NUM> of the housing <NUM>.

At this point, pushing the screw <NUM>, seat <NUM> and pinion <NUM> upwards again allows to bring the surface <NUM> to rest on the inner surface of the folding <NUM> of the second end <NUM> of the shell <NUM> so that the protrusion <NUM> of the housing <NUM> engages said hole <NUM> and so that the portion of the head <NUM> of the pinion <NUM> proximal to the hole overcomes the tooth 25C of the second aperture 25B of the shell <NUM> (<FIG>).

Preferably, the sheet <NUM> is fitted onto the shell <NUM> by inserting it with the second face <NUM> facing toward the second end <NUM> of the shell, until it reaches the flange <NUM> on which it rests (<FIG>). At this point, the two locking wings <NUM> are folded on said flange.

Lastly, the two second tabs <NUM> of the shell <NUM> are folded inwards so that each engages a corresponding groove <NUM> of the nut screw <NUM> (<FIG>), while the first tab <NUM> is still folded inwards but so as to prevent the head <NUM> of the screw <NUM> moves away from the second end <NUM> of the shell <NUM> releasing the housing <NUM> from engagement with the hole <NUM> and, as a result, the head <NUM> of the pinion <NUM> from the locking of the tooth 25C of the second aperture 2B of the shell.

The foot <NUM> according to the present invention thus fitted is ready to be inserted into an appropriate seat obtained on the side of the furniture.

In the light of the above, it is clear that both the production and the fitting of the foot <NUM> are simple so as to facilitate the work of the operators. As a matter of fact, thanks to the metal sheet from which the shell <NUM> is obtained, the production is significantly simplified with respect to conventional shells made of several pieces or as a single piece already formed.

In addition, the use of a housing specifically designed to contain the pinion in the shell, providing a broad window on the shell such to allow a greater extension of the teeth and possibly also an appropriate aperture for housing the end of the stem of the pinion, allow to strengthen the meshing with the crown gear of the screw. As a result, the foot of the invention can bear significant loads even during the adjustment thereof. As a matter of fact, as shown in the section of <FIG>, it can be observed that the teeth <NUM> of the pinion <NUM> extend until they occupy the space that would have been occupied by the wall of the shell <NUM>. In other words, the circumferential and longitudinal extension of the window 25B is such to potentially allow the insertion of a head of a pinion with dimensions of the teeth greater than those normally used.

Still, the low number of components simplifies the manufacture and fitting, besides increasing the operational duration given the limited interaction between said components.

Numerous variants to the foot according to the present invention can be adopted by the person skilled in the art, but without departing from the scope of protection of the attached claims.

For example, the materials chosen for producing the components of the foot are generally made of metal, like steel, aluminium or alloys.

Claim 1:
Adjustable foot (<NUM>) for levelling furniture, comprising a shell (<NUM>) extending along a rectilinear axis (X-X) to cover a moving mechanism consisting in a screw (<NUM>) coupled to a nut-screw (<NUM>), the nut-screw being provided with an extended portion (<NUM>) for resting on a ground, and in a pinion (<NUM>) for moving the screw with respect to the nut-screw, characterized in that said shell (<NUM>) is formed by a metal sheet folded on itself with a first end (<NUM>) opened and with a flange (<NUM>), a second end (<NUM>) bounded by an edge (23A), and a slot (<NUM>) contacting the two longitudinal-folded edge, which slot defines a first radial aperture (25A) in a diametrically opposite position to which a radial window is obtained (25B) allowing the passage of the head (<NUM>) of said pinion (<NUM>), and in that it further comprises a housing (<NUM>) for rotatably housing on its axis (A-A) the pinion (<NUM>) within the shell (<NUM>) and interposing between said pinion and the shell.