Servomechanism for furniture leaf

Abstract

A servomechanism for sliding doors of furniture item is described. An eddy-currents magnetic damper (80) to dampen the door is used to brake two carriages (26) mounted slidingly on the linear guides (20) for slidingly supporting the door.

Claims

1. Servomechanism for moving a door of a furniture item (MC) comprising: two parallel, horizontal linear guides (20), two carriages (26) respectively slidingly mounted, via wheels, on the linear guides (20) for slidingly supporting a leaf, an articulated parallelogram formed by a vertical bar (40) which is connected to the two carriages and is mounted for supporting and moving the door, and two equal arms (50) pivoted to a side panel of the furniture item, a cam (54) integral with an arm, a movable slider (56) which is biased toward the cam by an elastic element so as to push on the cam and rotate the arm, an eddy-currents magnetic damer (80) to dampen the door; wherein the magnetic damper comprises a linear guide in which a skid (80) integral with the leaf is slidingly mounted, the linear guide and/or the skid comprising permanent magnets (88) and, respectively, the skid and/or the linear guide comprising a metal track (70) which a magnetic field generated by the permanent magnets can hit and slide on; wherein the linear guide of the magnetic damper and said one of said two parallel linear guides are constituted of a single section bar (68), and wherein said single section bar or said track comprises or consists of two cantilevered coplanar fins, on whose opposed flat sides a skid comprised in the damper is slidingly mounted and comprises permanent magnets.

2. Servomechanism according to claim 1, wherein the magnetic damper comprises a linear guide in which a skid (80) integral with the leaf is slidingly mounted, the linear guide and/or the skid comprising permanent magnets (88) and, respectively, the skid and/or the linear guide comprising a metal track (70) which a magnetic field generated by the permanent magnets can hit and slide on.

3. Servomechanism according to claim 2, wherein the linear guide of the magnetic damer is integrated in one of said two parallel linear guides.

4. Servomechanism according to claim 1, wherein the metal track is made up of a material selected from aluminum, copper or high-carbon steel.

5. Servomechanism according to claim 1, wherein said single section bar (68) comprises a channel for a wheel comprised in one of said carriages.

6. Servomechanism according to claim 1, wherein the skid comprises two flat, parallel elements (82), spaced apart, mounted so that they can slide while keeping the coplanar fins therebetween, on each flat element being present permanent magnets (88).

7. Servomechanism according to claim 6, wherein the two flat parallel elements each comprise a low-carbon steel plate on which permanent magnets an arranged.

8. Servomechanism according to claim 6, wherein each flat element comprises a row of permanent magnets aligned along the direction of the length of the track or of one or of each fin, the two rows being parallel and arranged respectively on an opposite side of the track or opposite to the fin, wherein all the permanent magnets of a or each row have N-S polar axes parallel to each other and the N-S polar axis of each permanent magnet, belonging to a row placed along a side of the track or of the fin, coincides with the N-S polar axis of a permanent magnet of a row placed on the opposite side of the track or fin, and the permanent magnets of one or of each row are oriented so as to have N-S polar axis with alternate direction.

Description

(1) The advantages of the invention will be even clearer from the following description of a preferred example of servomechanism, reference making to the attached drawing in which

(2) FIG. 1 shows a three-dimensional view of the servomechanism mounted on a piece of furniture;

(3) FIG. 2 shows an enlargement of FIG. 1;

(4) FIG. 3 shows isolated components of FIG. 2;

(5) FIG. 4 shows a simplified side view of a section bar;

(6) FIG. 5 shows a cross-sectional view according to the V-V plane;

(7) FIG. 6 shows a cross-sectional view according to the VI-VI plane;

(8) FIG. 7 shows an enlargement of FIG. 5,

(9) FIG. 8 shows an enlargement of FIG. 6.

(10) In the figures, equal numbers indicate equal or conceptually similar parts, and elements are described as being used. To not crowd the figures, some numerical references are omitted.

(11) A piece of furniture MC comprises a compartment, formed by a ceiling 10, a bottom 14, a back 16 and side walls 12, in front of which a door (not shown) is slidingly mounted to close the compartment. The furniture MC may have even more compartments.

(12) The furniture MC is equipped with a servomechanism to move the door between a closing position and an opening position. In the closed position the door's plane is parallel and superimposed on a side wall 12, while in the open position, the door closes the compartment, the door's plane becoming parallel to the back 16. Thus, the door while moving rotates by 90 degrees about a vertical axis.

(13) The servomechanism comprises two parallel and horizontal linear guides 20 mounted at a certain distance from each other on a side wall 12.

(14) Two carriages 26 are slidingly mounted by means of wheels 28 on the linear guides 20 to slidingly support the door back and forth along the wall side 12.

(15) To apply a return force during the closing movement of the door or to apply an extraction force during the opening movement of the door, the furniture MC comprises an articulated parallelogram mounted on the side wall 12 between the two guides 20. The articulated parallelogram is formed by a vertical bar 40, connected to the two carriages 26 and on which the door is mounted, and two equal arms 50 pivoted to the wall 12.

(16) On each arm 50 there is a cam 54, on which can slide a movable slider 56 pushed towards the cam 54 by a spring 60. Thus the slider 56 presses on the cam 54 and rotates the arm 50 in order to push the door toward the closing position or the opening position.

(17) For greater stability it is preferable to “close” the articulated parallelogram with a vertical bar 61 pivoted between the cams 54.

(18) The furniture MC comprises an eddy-current dampening magnetic shock absorber or system to dampen the door while it moves up to the end-of-travel point of the closing position.

(19) The upper linear guide 20 is a metal section bar 68, e.g. made of aluminum or copper, whose cross-section is shaped to form rectilinear channels to accommodate a carriage 26 and a skid 80 of the shock absorber or cushioning system.

(20) The carriage 26 and the skid 80 do not necessarily have to be separated elements; they could be a single element.

(21) The section bar 68 has a portion 70, e.g. made of aluminum or copper, with C-shaped cross-section, i.e. a section comprising two cantilevered fins 72 which are flat, coplanar and parallel. The cantilevered fins 72 are separated from each other by a certain distance 74 and are offset with respect to a flat wall 92 of the section bar 68 (the central part of the C).

(22) The skid 80 (FIGS. 5 and 6) is formed by two parallel and slightly spaced planes 82, which are mounted to slide while keeping the fins 72 therebetween (thanks to a sandwich structure).

(23) The planes 82 have a specular structure and are formed by a flat metallic plate 86, e.g. made of low carbon-content steel, on which there are arranged rows of permanent magnets 88. In the example shown, there are two parallel rows of permanent magnets 88 for each plane 82, and each row of permanent magnets 88 in a plane 82 cooperates with a homologous row of permanent magnets 88 in the other plane 82 to induce a magnetic field on the fin 72 they are facing.

(24) The permanent magnets 88 in each plane 82 have a polar axis P orthogonal to the plate 86 and to each fin 72.

(25) Taken any reference orientation on a straight line orthogonal to the flat surface of the fins 72, in each row of permanent magnets 88 there are magnets with N-S polarity alternating with magnets with S-N polarity. That is to say that, in a row, if a magnet has N-S polarity the next magnet has S-N polarity, and vice versa.

(26) Each magnet 88 of a row faces, on the other side of the fin 72 along the aforesaid line, a magnet 88 with an equally-oriented polar axis. That means that, in a row, the magnetic pole closest to the fin 72 of each magnet 88 is different from the pole of a counterpart magnet located on the other side of the fin 80. In short, considered two 88 magnets arranged along the same line orthogonal to a flap 72, their magnetic poles closest to the flap 72 are opposite (see example of N/S poles in FIGS. 7 and 8).

(27) This way, the magnets 88 of a row cooperate with the homologues magnets 88 of the opposite row to create many successive crossings of magnetic flux inside a fin 72 (see FIG. 8).

(28) Placing magnets 88 on two opposite sides of a fin 72 reinforces the magnetic flux that passes through the fin 72, thereby increasing the resulting braking effect deriving from eddy currents. With less braking efficiency, one may also use a single row of magnets 88 for interacting with a fin 72.

(29) In the example shown, for each fin 72 there are two rows of cooperating magnets 88, therefore altogether the skid 80 comprises four rows of magnets 88, two by two coplanar. The rows of magnets may be in different number than what is illustrated.

(30) The permanent magnets 88 are preferably enclosed and separated by elements 76, made preferably but not necessarily out of plastic material, also used at the center of the skid 80 to space the planes 82.

(31) Operation

(32) When the door moves in opposite directions along the wall 12 on the guides 20, the skid 80 slides correspondingly back and forth on the section bar 68. The sliding entails that the planes 82, with the magnets 88 carried by them, move relative to the fins 72. Since the magnets 88 are oriented in order to concentrate the magnetic field towards the fin 72, the fin 72 is hit by a considerable magnetic flux that changes over time. Consequently in the fin 72 eddy currents are induced which create a magnetic field of opposite polarity to the inducing one. The two fields attract each other and the skid 80 is braked by and from the fin 72.