EP2281096B1 - Furniture drive - Google Patents

Description

The present invention relates to a furniture drive for driving a movable furniture part having the features of the preamble of claim 1.

For various reasons (lower cost, space requirements, power requirements), it is desirable to use the smallest possible electric motor, which moreover advantageously without complicated control electronics to control the torque.

From the earlier priority Austrian patent application A 1542/2007 The Applicant is a furniture drive with a varying ratio out, which is achieved by a toggle lever assembly.

The EP 1 194 708 B1 describes a drive device for driving an actuator with a trained as a non-circular gear stage, the non-circular gear has two meshing gears. This document teaches that in many applications of transmissions a maximum output torque is needed only in one position, such requirements are to occur for example in transmissions that meet a closing function.

In a drive via an electric motor and a transmission with constant translation, there is the disadvantage according to this document that the height of the transmission must be high enough that the maximum torque can be achieved with the electric motor used, which usually requires a high gear ratio , On the other hand, a high gear ratio also means a long positioning time of the gearbox.

Instead of a transmission with constant translation beats the EP 1 194 708 B1 a two-stage transmission, wherein the first gear stage is designed as a harmonic drive (harmonic drive gear) and the second stage as a non-circular gear.

Concrete examples of advantageous ratio ratios does not teach this document. Special attention is paid to the interplay between torque and positioning time.

The EP 1 194 708 B1 is due to its fixation on the voltage ratio between torque and operating time in applications where this tension ratio plays only a very minor role of only very limited importance.

From the EP 1 898 036 A1 shows an actuation actuator for a vehicle door, which is provided with a non-circular gear, which has two intermeshing gears. This document teaches that in motor vehicle flaps it is necessary to apply sufficient torque to the motor vehicle door to overcome the reaction forces caused by a seal during the closing operation. This is achieved so that the vehicle door is operated over a relatively small gear ratio during the majority of the closing movement. As the motor vehicle door approaches the closed position, and particularly when pressed against a seal, it is driven at a higher gear ratio.

The opening movement is in the EP 1 898 036 A1 not treated, which is due to the fact that vehicle doors are usually opened manually.

With respect to a generic furniture drive, with an actuator moved back and forth between two end positions, is therefore the EP 1 898 036 A1 Not relevant.

An even more remote prior art provides the DE 197 39 851 A1 This teaches a windshield wiper device with two wiper levers driven by a single electric motor, wherein a non-circular gear is provided for generating a delay or acceleration of the reciprocating motion of the windscreen wiper lever in predetermined areas.

A furniture drive with the features of the preamble of claim 1 proceeds from the WO 2007/035971 A1 out:

The object of the invention is to provide a furniture drive, which has a more advantageous operating behavior using such a known as non-circular transmission than such furniture drives, in which the transmission ratio over the entire path of movement of the movable furniture part is constant.

The invention solves this problem by a furniture drive with the features of claim 1.

Due to the fixed connection of one of the two gears of the non-circular gear with the actuator and the fact that the two gears of the non-circular gear mesh with each other, it is ensured that there is a 1: 1 between the position of the actuator and the relative position of the two gears of the non-circular gear - Correspondence gives. In particular, the non-circular gear has two end positions, which correspond to the end positions of the actuator. This measure makes it possible to further provide that, upon rotation of the gears of the non-circular gear starting from a first of the two end positions to the other end position, the transmission ratio steadily decreases.

When the furniture drive according to the invention is therefore achieved that the force exerted by the electric motor via the gear on the actuator torque, starting from the first end position of the non-circular gear and the above-mentioned correspondence thus in the region of the corresponding end position of the actuator is greatest. In the assembled state of the furniture drive on or in a furniture body, wherein the actuator is connected to the driven furniture part, the end positions of the actuator correspond to a closed or completely open position of the driven furniture part. According to the invention is thus at the start of the first end position (closed position of the furniture part) when the electric motor starts slowly, a particularly large and therefore optimal torque available.

In the preferred embodiment, the furniture part is a flap that can be easily set in motion from the open end position by the support of gravity and the absence of a charged energy storage automatic loading mechanism. Starting from the closed position, the flap can be easily set in motion by the inventive measure, since the maximum torque is available here.

It should be noted that the fixed connection or coupling of one of the two gears of the non-circular gear with the actuator, of course, can be solvable per se, for example, to facilitate the assembly of the furniture drive or to replace parts. It is only important that a correspondence between the end positions of the actuator and the end positions of the non-circular gear through the connection or coupling can be ensured during operation of the furniture drive.

Further advantageous embodiments of the invention are defined in the dependent claims.

Protection is also desired for a piece of furniture with a movably mounted furniture part (for example, flap, door or drawer) with a furniture drive according to the invention.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Möbelantriebes,

Fig. 2a, 2b

den Kräftestrang zwischen Elektromotor und Aktuator des in Fig. 1 dargestellten Möbelantriebes in einer perspektivischen Ansicht von vorne bzw. hinten,

Fig. 3

eine Darstellung entsprechend der Fig. 2a, 2b, wobei jedoch auf die Darstellung aller nicht unmittelbar zum Antriebsstrang gehörender Bauteile verzichtet wurde,

Fig. 4a-4c

ein bei einem erfindungsgemäßen Möbelantrieb einsetzbares Unrundgetriebe in drei verschiedenen Stellungen und

Fig. 5a, 5b

den erfindungsgemäßen Möbelantrieb in Montagestellung in einem Möbelkorpus.

Further advantages and details of the invention will become apparent from the figures and the associated description of the figures. Showing:

Fig. 1

a perspective view of a furniture drive according to the invention,

Fig. 2a, 2b

the power train between electric motor and actuator of in Fig. 1 shown furniture drive in a perspective view from the front or rear,

Fig. 3

a representation according to the Fig. 2a . 2 B However, with the representation of all not directly to the drive train belonging components was omitted,

Fig. 4a-4c

a usable in a furniture drive according to the invention non-circular gear in three different positions and

Fig. 5a, 5b

the furniture drive according to the invention in the assembled position in a furniture body.

The in Fig. 1 illustrated furniture units 1, in this embodiment consists of two detachably interconnected units 13, 14. In this case, the unit 14 is a fully functional actuator for a furniture flap, as he is known, so it does not have to be discussed in detail. Particular attention should be drawn only to the arranged here in the assembly 14 actuator 4, via which the exercise of force on the movable furniture part 2 via a lever mechanism 15 (see Fig. 5 ) he follows.

The electric motor 3, the gear 5 and a shaft 12 non-rotatably connected to the actuator 4 are arranged in the assembly 13, which will be explained in more detail in the following figures.

The Fig. 2a and 2 B The power transmission interface between the two units 13, 14 in this case represents the drivable by the electric motor 3 via the gear 5 shaft 12, which is formed profiled and in a correspondingly formed recess, with the actuator 4 in Connection stands, intervenes. If the shaft 12 rotates, then the actuator 4 is rotated accordingly.

The powertrain (see Fig. 2a ) of the furniture drive 1 according to the invention begins in Fig. 2a left with the electric motor 3, which acts via a worm gear with a first gear stage of the transmission 5 together. Between the electric motor 3 and in the transmission 5 In this case, a dog clutch 9 is arranged, which serves the sound decoupling and the compensation of axle errors. The transmission 5, in this embodiment, further comprises an overload protection 10, which is intended to prevent damage to the electric motor 3 by an excessive exertion of force on the actuator 4. A one-way clutch 16 allows the movement of the furniture part 2 without obstruction by the electric motor 3 over a defined area (eg shortly before the closed position of the furniture part 2). In this area, a preferred movement of the furniture part 2 by purely mechanical components (eg collection device) achieved instead of having to regulate the electric motor 3 via a control for this purpose.

Of particular interest now are the particularly good at Fig. 3 recognizable gears 7, 8 designed as a non-circular gear 6 gear stage. Shown are two different radii r1, r2, wherein the radii r1 refer to the gear 7 and the radii r2 to the gear 8. Of importance now is that the respective radii r1, r2 (each measured from the respective axis of rotation of the gear to the ring gear) change in a predefined manner so as to give the desired torque curve. Since here the axes of rotation of the two gears 7, 8 are arranged at a fixed distance from one another, the radius r1 of the gear 7 coupled to the electric motor 3 or the radius r2 of the gear 8 connected to the actuator 4 must each change so that in sum exactly the distance between the two axes of rotation results.

The Fig. 4a - 4c show an inventively usable non-circular gear 6, which in the concrete embodiment of something in the Figures 1 - 3 illustrated, non-circular gear 6 different. However, this difference relates only to the formation of the gears 7,8 in a region remote from the sprocket and is therefore insignificant for the inventive mode of action.

In the Fig. 4a or 4c illustrated end positions of the non-circular gear 6 correspond to a closed end position ( Fig. 4a ) of the furniture part 2 or with a fully open end position ( Fig. 4c ) of the movable furniture part 2. The position of Fig. 4b It is important that the transmission ratio of the non-circular gear and thus the entire transmission 5 at a rotation of the gears 7, 8, starting from the first end position of the Fig. 4a to the other end position ( Fig. 4c ) down steadily. The gear ratio thus has at the other end position a minimum value (equivalent to a minimum torque acting as the output gear 8 and a maximum peripheral speed of the gear 8).

Depending on the position of the two gears 7, 8 to each other, different effective lever lengths for the power transmission and thus the desired different torques arise.

The Fig. 5a and 5b each show the front and rear view of a piece of furniture 11, wherein on the left side of the furniture body, an inventive furniture drive 1 has been mounted. In the illustrated embodiment, an inventive furniture drive 1 is provided only on one side of the furniture body, while on the other side, only the mechanical unit 14 is arranged. Conceivable, of course, would be the provision of assemblies 13 and thus complete inventive furniture drives 1 on both sides of the furniture body.

The triggering of this invention furniture drive 1 can be effected in a known manner via a touch-latch functionality. With this functionality, a slight movement of the movable furniture part 2 caused by a user (e.g., pushing or pulling) detected by a user is detected, and consequently, the activation command is given to the furniture drive 1. This is done by an already known control unit for the furniture drive 1, which may be integrated in the furniture drive 1 itself.

All representations of the figures are true to scale and angle.

Claims (7)

1. A furniture drive for driving a movable furniture part comprising an electric motor, an actuator reciprocatable between two end positions to apply force to the furniture part to be driven, and a transmission connected between the electric motor and the actuator, wherein a freewheel coupling and/or an overload safety device is or are connected between the gear coupled to the electric motor and the electric motor, characterised in that the transmission has at least one transmission stage in the form of an eccentric transmission with two mutually meshing gears, and one of the two gears (7, 8) is fixedly connected or coupled to the actuator (4) and the other gear (7, 8) is coupled to the electric motor (3) so that the eccentric transmission (6) has two end positions corresponding to the end positions of the actuator (4) and the transmission ratio continuously decreases upon a rotation of the gears (7, 8) starting from a first of the two end positions towards the other end position and is at a minimum value at the other end position.
2. A furniture drive as set forth in claim 1 characterised in that the axes of rotation of the two gears (7, 8) of the eccentric transmission (6) are arranged at a fixed spacing relative to each other.
3. A furniture drive as set forth in claim 2 characterised in that the radius (r1) of the gear (7) coupled to the electric motor (3) increases starting from the first end position towards the other end position and the radius (r2) of the gear (8) connected or coupled to the actuator (4) correspondingly decreases.
4. A furniture drive as set forth in one of claims 1 through 3 characterised in that the actuator (4) is drivable by the gear (8) by way of a shaft (12) non-rotatably connected to the gear (8).
5. An article of furniture comprising a movably mounted furniture part, characterised by a furniture drive as set forth in one of claims 1 through 4.
6. An article of furniture as set forth in claim 6 wherein the furniture part (2) is in the form of a flap, door or drawer.
7. An article of furniture as set forth in claim 5 or claim 6 characterised in that the first end position corresponds to that end position of the actuator (4) at which the movably mounted furniture part is in its closed position.

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