Patent ID: 12188275

DETAILED DESCRIPTION OF THE INVENTION

FIGS.1aand1b, which show a furniture drive101according to the state of the art, have already been described at the beginning.

In comparison to that,FIGS.2aand2bshow an embodiment of a furniture drive1according to the invention for moving a furniture front part2relative to a furniture carcass3(see also the followingFIG.3), comprising a main body4that can be fastened to the furniture carcass3and an actuating arm5, which is mounted rotatable about at least one first axis of rotation6on the main body4.

The actuating arm5has several levers7,8,9connected to each other in an articulated manner.

The actuating arm5has a fastening interface11arranged in an imaginary fastening interface plane10via which the furniture front part2can be fastened to the actuating arm5. The fastening interface plane10is indicated by means of a dot-dashed line.

The actuating arm5can be moved continuously with respect to the at least one first axis of rotation6between a first rotational position and a second rotational position. The first rotational position corresponds to a closed position of the furniture front part2that can be fastened to the actuating arm5(and, particularly, the position of the first lever7when the fastening interface11and furniture front part2are in the closed position), and can be assigned a rotational angle α of 0°. The second rotational position corresponds to a maximum open position of the furniture front part2that can be fastened to the actuating arm5(and, particularly, the position of the first lever7when the fastening interface11and furniture front part2are in the maximum open position) and can be assigned a rotational angle α greater than 0°. The left-hand edge, in the figure, of the first lever7which is marked with a dashed line can be used, for example, as reference for the measurement of the rotational angle α. However, the rotational angle α can also be determined in relation to another axis of rotation and/or in relation to another reference. The rotational angle α is drawn in by way of example inFIG.5a.

During a rotational movement of the actuating arm5, the fastening interface plane10, and thus the furniture front part2that can be fastened to the actuating arm5, passes through different front part angles β. The front part angle β is drawn in by way of example inFIG.5a, and is the angle between a front face37of the furniture carcass3(seeFIG.3) and the fastening interface plane10.

Each rotational angle α of the actuating arm5can be assigned a front part angle β=f (α) of the fastening interface plane10using a function f, beginning with a front part angle β of 0°, which can be assigned to the rotational angle α of the actuating arm5of 0°.

In the embodiment represented, levers7,8,9of the actuating arm5form a four-pivot point geometry, wherein one of the four pivot points of the four-pivot point geometry corresponds to the at least one first axis of rotation6of the actuating arm5.

The actuating arm5is mounted rotatable about at least one second axis of rotation15on the main body4, and the main body4of the furniture drive1has a front opening16through which the actuating arm5protrudes at least in areas at least in the maximum open position. The second axis of rotation15is located a smaller normal distance17from the front opening16than is the first axis of rotation6, and the main body4of the furniture drive1has a top side18which faces a top panel19of the furniture carcass3when the furniture drive1is fastened to the furniture carcass3. The second axis of rotation15is located a smaller normal distance20from the top side18than is the first axis of rotation6.

The second axis of rotation15corresponds to a pivot point of the four-pivot point geometry of the levers7,8,9of the actuating arm5.

Compared with the furniture drive101according toFIGS.1aand1bknown from the state of the art, the distance between the two axes of rotation6and15of the furniture drive1is much smaller than the distance between the two axes of rotation106and115of the furniture drive101.

The actuating arm5comprises three levers7,8,9connected to each other in an articulated manner including one angled lever9, wherein two sections21,22of the angled lever9form an angle23of substantially 90° relative to one another.

Two of the provided levers7,8,9of the actuating arm5, namely levers7and8, are arranged nested in one another in at least one rotational position of the actuating arm5, with the result that the two levers7,8are formed substantially gap-free in a top view from the side. The first lever7is formed U-shaped in a cross section, and a second lever8can be arranged or is at least partially arranged between the vertical bars (legs) of the U shape.

The actuating arm5has the first lever7and the second lever8, via which the actuating arm5is rotatably connected to the main body4, and the third lever9, on which the fastening interface11is formed. The first lever7and the second lever8are connected to the third lever9in an articulated manner. For this, a first pivot point43, which connects levers7and9, and a second pivot point44, which connects levers8and9, are provided.

The two levers7and8of the actuating arm5can be detachably connected to the main body4of the furniture drive1.

InFIG.2b, the position of the two effective lever arms45and46relative to the main body4is again represented in the first rotational position of the actuating arm5, i.e. the closed position.

FIG.3shows an embodiment of a piece of furniture31with a furniture drive1. The piece of furniture31comprises a furniture carcass3, a furniture front part2and at least one furniture drive1. The main body4of the furniture drive1is fastened to the furniture carcass3, preferably in and/or on a side wall32of the furniture carcass3, and the furniture front part2is fastened to the actuating arm5of the at least one furniture drive1via the fastening interface11.

The piece of furniture31can also comprise at least one further furniture drive1connected to the furniture carcass3and the furniture front part2, wherein the two furniture drives1are connected to each other only via the furniture front part2and the furniture carcass3.

The furniture carcass3has a front face37that faces the furniture front part2in the closed position. In the closed position, the furniture front part2has a front part angle β of 0° relative to the front face37, while in the maximum open position, the furniture front part2has a front part angle β of between 60° and 80° relative to the front face37. This maximum open position is represented inFIG.3.

In addition to a top panel19, the piece of furniture31can also comprise a shelf47and/or a cornice39.

FIG.4shows the embodiment of the furniture drive1with an open casing, with the result that the inner workings of the furniture drive1can be seen.

The furniture drive1can have at least one energy storage mechanism24, preferably having at least one spring element25and preferably mounted on the main body4, via which a force can be applied to the actuating arm5in order to compensate for a weight of the furniture front part2that can be fastened to the actuating arm5.

As in the represented case, a transfer mechanism26can be provided, with which a force that can be stored in the at least one energy storage mechanism24can be transferred to the actuating arm5. The transfer mechanism26comprises at least one intermediate lever27, and the at least one energy storage mechanism24is connected to the at least one intermediate lever27via an adjustable force linkage point28.

The transfer mechanism26comprises a pressure piece29and at least one positioning contour30, on which the at least one pressure piece29can be displaceably supported. The at least one pressure piece29is arranged on the at least one intermediate lever27of the transfer mechanism26, and the at least one positioning contour30is arranged on the actuating arm5, or vice versa.

The furniture drive1can also comprise a damper48, with which a movement of the actuating arm5in the opening and/or closing direction can be damped.

FIGS.5a-5eshow the embodiment of the furniture drive1, wherein the actuating arm5is arranged in different rotational positions relative to the main body4, between a first rotational position, which corresponds to a closed position of the furniture front part2that can be fastened to the actuating arm5(partial figure a), and a second rotational position, which corresponds to a maximum open position of the furniture front part2that can be fastened to the actuating arm5(partial figure e). PartialFIGS.5b,5cand5dshow intermediate rotational positions.

If the front part angle β is plotted as a function of the rotational angle α, then the progression represented inFIG.6aresults (continuous line). The progression of the front part angle β of the furniture drive101known from the state of the art (dot-dash line) and the curves of a furniture drive with a 1-pivot point linkage (dashed lines) are represented in comparison to that.

If the derivative f′ (α) is calculated in each case and plotted against the rotational angle α, then the progressions represented inFIG.6bresult.

In the case of a furniture drive with a 1-pivot point linkage, the gradient is 1 at every point. In the case of the furniture drive101known from the state of the art, the front part angle β initially changes gradually and then increasingly sharply. In comparison to that, in the case of the furniture drive1the front part angle β changes comparatively sharply even at the beginning of the opening movement. This is realized in technical terms in that the levers7,8,9of the actuating arm5, or the four pivot points of the four-pivot point geometry of the levers7,8,9of the actuating arm5, are arranged relative to one another such that a gradient f′ (α) of the function f is greater than 0.2, preferably greater than 0.3, at least over a rotational angle range of the actuating arm5between 0° and 25°, preferably over the whole rotational angle range of the actuating arm5.

If the stabilities of the furniture drive with a 1-pivot point linkage, the furniture drive101known from the state of the art and a furniture drive1according to the invention are now compared, it can thus be established that the furniture drive with a 1-pivot point linkage is the most stable solution and the furniture drive101known from the state of the art is the least stable solution, which requires a synchronization mechanism. It has now been found, surprisingly for a person skilled in the art, that furniture drives1in which a gradient f′ (α) of the function f is greater than 0.2, preferably greater than 0.3, at least over a rotational angle range of the actuating arm5between 0° and 25°, preferably over the whole rotational angle range of the actuating arm5, already have a sufficiently high stability which makes it possible to dispense with the use of a synchronization mechanism separate from the furniture front part. In the specifically represented case, the gradient f′ (α) of the function f is above 0.4 in the whole rotational angle range of the actuating arm5.

FIG.7shows a comparative representation of the position of the furniture front parts2and102relative to the furniture carcass of a piece of furniture according to the state of the art (continuous lines) and a piece of furniture31according to the invention (dashed lines). It can be clearly seen that, in the case of the piece of furniture31according to the invention, the furniture front part2starts to rotate immediately at the beginning of the opening movement, whereas, in the case of the state of the art, the furniture front part is initially moved substantially parallel away from the front face of the furniture carcass. The cornice39is circumnavigated in both cases.

FIGS.8ato8fand9ato9f, in a comparison, show, on the one hand, the movement of the lever arms145and146in the case of a furniture drive101according to the state of the art and, on the other hand, the lever arms45and46in the case of a preferred embodiment of the furniture drive1according to the invention in the course of an opening movement starting from the closed position represented in partial figure a, i.e. the first rotational position of the actuating arm5, up until the maximum open position represented in partial figure f, i.e. the second rotational position of the actuating arm5.

It can be established that a dead center of the lever geometry is crossed at an earlier point in time in the course of the opening movement in the case of the furniture drive101.

InFIGS.9cand9d, the instantaneous center of rotation of the lever geometry is represented in space by way of example from the point of intersection of the two lever arms45and46. If the instantaneous center of rotation is plotted for each rotational position of the furniture drive1and101, then the curves134and34represented inFIGS.10a(for the furniture drive101) and10b(for the furniture drive1) result.

It emerges fromFIG.10bthat the instantaneous center of rotation33of the furniture front part2or of the lever arrangement of the levers7,8,9of the actuating arm5can be moved along an imaginary curve34in space relative to the furniture carcass3when the furniture front part2is moved between the closed position and the maximum open position. The furniture carcass3has a top panel19, and an end point35of the curve34of the instantaneous center of rotation33, which corresponds to the closed position, is less than 500 mm, preferably less than 250 mm, away from a top side36of the top panel19(drawn in as distance49in the figure). The furniture carcass3also has a front face37that faces the furniture front part2in the closed position, and an end point35of the curve34of the instantaneous center of rotation33, which corresponds to the closed position, is less than 75 mm, preferably less than 50 mm, away from an imaginary extension (i.e., a plane)38of the front face37upwards beyond (above) the furniture carcass3(drawn in as distance50in the figure).

In comparison to that, the distance149of the end point135of the curve134of the instantaneous center of rotation133from the top side136of the top panel119of the piece of furniture131in the case of the furniture drive101is approx. 1700 mm and the distance150from the imaginary extension138is approx. 190 mm and thus much greater, which results in an unstable arrangement, which needs to be stabilized with a synchronization rod.

In the enlarged partial views ofFIGS.10aand10b, the circumnavigation of the cornices139and39is additionally represented.

The furniture carcass3of the piece of furniture31comprises a cornice39, wherein, in the case of a movement between the closed position and the maximum open position, the furniture front part2can be moved unhindered around the cornice39without an upper edge40of the furniture front part2that faces the cornice39in the closed position colliding with the cornice39. Preferably, the furniture carcass3has a top panel19, and a top side41of the cornice39is between 75 mm and 100 mm away from the top side36of the top panel19(drawn in as distance12in the figure), and/or the furniture carcass3has a front face37that faces the furniture front part2in the closed position, and a front side42of the cornice39is between 40 and 75 mm away from an imaginary extension38of the front face37upwards beyond the furniture carcass3(drawn in as distance13in the figure).

InFIG.10a, the edge of the furniture front part102is provided with the reference number140, the top side of the cornice139is provided with the reference number141and the front side of the cornice139is provided with the reference number142.

No piece of furniture is known from the state of the art which fulfils both conditions, namely on the one hand a curve34of the instantaneous center of rotation33arranged very close to the fixed pivot points of the furniture drive1and, on the other hand, the possibility to circumnavigate an optionally present cornice39without colliding.