EP1874158B1 - Ejection device for a movable part of a piece of furniture - Google Patents

Description

The present invention relates to an ejection device for a movable furniture part, with a lever for transmitting power to the movable furniture part, wherein the lever has a lever body which is rotatably mounted limited on the one hand about a rotation axis and on the other hand has a free end of the lever.

Such ejection devices have been used for a long time. In this case, a torque M is exerted on the lever body via a drive unit which is usually designed electrically. If the ejection device is arranged in a furniture carcass, then the force F exerted by the lever body on the movable furniture part results as a function of the force arm r by the formula F = M / r. See for example DE 1778452 A1

In a predetermined torque of the drive unit M therefore, the force applied to the movable furniture part F force F is smaller, the larger the force arm r is. The size of the force arm r of course corresponds to the distance between the axis of rotation and the point at which the lever body touches the movable furniture door. Since the lever body rests in the prior art with its free end of the lever on the movable furniture part, there corresponds to the power arm r substantially the length of the lever body.

Since the size of the distance over which the lever body can exert any force F on the movable furniture part before the movable furniture part lifts off from the lever body is influenced by the length of the lever body, the lever body can not be made too short.

This brings in the prior art has the disadvantage that due to the large force arm r only a small force F can be transferred to the movable furniture part. Especially in the initial acceleration phase, in which the movable furniture part must be accelerated from standstill, overcoming its inertia, this leads to a massive load on the drive unit and due to the low acceleration to a slow ejection process.

The object of the invention is to provide an ejection device in which these problems do not occur.

This object is achieved by an ejection device with the features of claim 1.

The provision of a curved area spaced from the axis of rotation and the free end of the lever has, in essence, the effect that, in the case of an ejection device mounted in a furniture body, the lever body first comes into contact with the curved area on the movable furniture part in the closed end position of the movable furniture part. Therefore, at the beginning of the ejection process, a shorter force arm r is effectively present than in the case of a lever according to the prior art with an identically dimensioned lever body.

This results in that at the beginning of the ejection process, a predetermined torque M of the drive unit is translated into a larger force F on the movable furniture part. On the one hand this reduces the load on the drive unit (for example in the case of an electric drive unit in the form of a lower thermal load) and on the other hand causes a shorter ejection time due to the greater acceleration. A further advantage is that due to the lower load of the drive unit and the noise is lower than in the prior art. Surprisingly, it has also been found that the inevitably occurring by the elasticity of the components involved (lever body, components of the movable furniture part and the furniture body) mechanical vibrations in an ejection device according to the invention over the prior art are greatly reduced.

In an advantageous embodiment of the invention can be provided that the lever body is elongated and adjacent to the curved portion at least one further curved portion is provided. These additional areas may well extend to the free end of the lever and / or to the axis of rotation. Depending on the dimensioning of the curved areas, the provision of a greater rotation of the lever can thereby be possible.

For example, it can be provided that the curved area is arcuate. If additional curved areas are provided, they may be part of the same arc.

Particularly preferably it is provided that the curved portion is formed such that in the mounted state of the ejection device, the point at which the lever body touches the movable furniture part, can move in the direction of the free end of the lever when ejecting the movable furniture part. As a result, a uniform change of the power arm r is effected and jumps in the applied force F avoided.

A simple releasability of the ejector is given by a touch-latch functionality. For this purpose, it can be provided that a sensor, preferably a rotary potentiometer, is provided for detecting the angular position of the lever. For example, it can then be provided that the signals of the sensor of a drive control unit can be fed, and that the drive unit of the ejection device can be activated by the drive control unit.

In the assembled state of the ejection device on the furniture body of a piece of furniture, the ejection device is of course to be arranged on the furniture body, that the lever body in the closed end position of the movable furniture part with its curved portion rests on the movable furniture part or can be applied.

In the case of a touch-latch functionality, the ejection device in the assembled state can be triggered by pressing in the movable furniture part in its closed end position into the furniture carcass.

Surprisingly, it has been found in a particularly preferred embodiment of the invention that the provision of a protruding portion on the movable furniture part, which cooperates with the curved portion of the lever body, leads to a further improvement of the ejection process. By this measure is namely achieved that the point of application of the lever body on the movable furniture part during the entire ejection process is substantially fixed to a predetermined position, namely that of the above range. This causes a more uniform application of force of the ejection device to the movable furniture part.

For example, it can additionally be provided that the projecting area comprises a roller disposed on the movable furniture part.

In order to cause the torque M of the drive unit during the initial acceleration phase of the movable furniture part in the largest possible force F is implemented, it is provided in a further advantageous embodiment of the invention that the ejection device is arranged in the furniture body, that is the point at which the lever body touches the movable furniture part in the closed end position, in the vicinity of the axis of rotation.

For example, it may be provided in this embodiment that the contact point is removed by more than half the length of the lever body from the free end of the lever.

Examples of movable furniture parts in the sense of this disclosure are drawers, flaps or furniture doors.

If the movable furniture part is designed as a drawer, the rear wall of the drawer is particularly suitable for the application of force by the lever. In this case, it can therefore be particularly preferred that the lever rests against the rear wall of the drawer in the closed end position of the drawer.

In the embodiment of the movable furniture part as a flap or furniture door can be provided accordingly that the lever rests in the closed end position on the leaf of the flap or the furniture door.

Fig. 1a, b, c

eine Ausstoßvorrichtung nach dem Stand der Technik in schematischer Darstellung sowie eine Darstellung der Kraft F sowie des der Antriebseinheit zugeführten Stromes I über den Ausstoßweg s,

Fig. 2a, b, c

analoge Darstellungen für ein weiteres Ausführungsbeispiel nach dem Stand der Technik,

Fig. 3a, b, c

analoge Darstellungen für ein erstes erfindungsgemäßes Ausführungsbeispiel,

Fig. 4a, b, c

analoge Darstellungen für ein weiteres erfindungsgemäßes Ausführungsbeispiel,

Fig. 5a, b, c

analoge Darstellungen für ein weiteres erfindungsgemäßes Ausführungsbeispiel,

Fig. 6a, b, c

analoge Darstellungen für ein weiteres erfindungsgemäßes Ausführungsbeispiel,

Fig. 7

eine schematische Darstellung des in Fig. 6a dargestellten Ausführungsbeispiels bei ausgeschwenktem Hebel und

Fig. 8

eine perspektivische Darstellung des in den Fig. 5a und 7 dargestellten Ausführungsbeispiels mit Komponenten für die Montage in einem Möbel,

Fig. 9a, b

ein schematischer Vergleich zwischen einem Hebel einer Ausstoßvorrichtung nach dem Stand der Technik und einem Hebel einer erfindungsgemäßen Ausstoßvorrichtung.

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

Fig. 1a, b, c

a discharge device according to the prior art in a schematic representation and a representation of the force F and the drive unit supplied to the current I via the discharge path s,

Fig. 2a, b, c

analogous representations for a further embodiment according to the prior art,

Fig. 3a, b, c

analogous representations for a first embodiment according to the invention,

Fig. 4a, b, c

analogous representations for a further embodiment according to the invention,

Fig. 5a, b, c

analogous representations for a further embodiment according to the invention,

Fig. 6a, b, c

analogous representations for a further embodiment according to the invention,

Fig. 7

a schematic representation of the in Fig. 6a illustrated embodiment with swung lever and

Fig. 8

a perspective view of the in the Fig. 5a and 7 illustrated embodiment with components for mounting in a piece of furniture,

Fig. 9a, b

a schematic comparison between a lever of a discharge device according to the prior art and a lever of an ejection device according to the invention.

It should be noted that the same scale was chosen in all figures.

Fig. 1a schematically shows an ejector 1 with a housing 5, on which a lever 2 is mounted rotatably limited. The ejection device 1 is mounted on a carrier element 6 and comprises an electric motor for driving the lever 2. The carrier element 6 is arranged on a furniture body, not shown. The lever 2 comprises a lever body 3 and a free lever end 4. At the free end of the lever 4, a roller 7 is arranged. In Fig. 1a it is the movable furniture part 8 to a drawer, which is located in the closed end position in the furniture body. The roller 7 abuts against a rear wall of the drawer.

In Fig. 1b the force F exerted on the rear wall of the drawer by the lever is represented by way s. The path s refers to the distance traveled by the rear wall of the drawer from the closed end position to the lifting off of the lever 2 Fig. 1c the current I supplied to the electric motor is represented via the path s. The problem with this prior art is that the force F exerted on the movable furniture part at the beginning of the ejection path is relatively small.

As in Fig. 2a was therefore already tried, the lever 2 after Fig. 1a to improve by the arrangement of another roller 7 to about half the lever length. (This embodiment is also not part of the invention.)

Out Fig. 2b It can be seen that this measure actually brings about a considerable increase in the force F initially exerted on the movable furniture part 8. From the Fig. 2b and 2c However, a major disadvantage of this embodiment immediately apparent. It can be seen that, as soon as the lever 2 is pivoted so far that the second roller 7, which is arranged at the free end of the lever 4, on the movable furniture part 8 to the plant comes, a jump of the force F and the current I arises. This jump is due to the fact that it comes in the system of the second roller 7 to a sudden increase in the effective force arm r, which is expressed to a sudden reduction in the force F. As Fig. 2c shows, this leads to a sudden increase of the current consumed by the electric motor I, since the electric motor due to the increased force arm r an increased torque M needed to apply the same force F. Since this can only be achieved at a lower speed, this also leads to a sudden reduction in the speed of the electric motor.

In the Fig. 3a Now, a first embodiment of an ejection device 1 according to the invention is shown. According to the invention, the lever body now has a curved area 9, which is spaced from the axis of rotation and the free end of the lever 4. In this embodiment, adjacent to the curved portion 9, a further curved portion 14 is arranged, which extends from the curved portion 9 to the free end of the lever 4. How out Fig. 3a is immediately apparent, the force exerted by the lever 2 on the movable furniture part 8 force F is initially considerably larger than that in the embodiments of the Fig. 1a and 2a the case is. This is due to the fact that the point 10 at which the lever body 3 touches the movable furniture part 8 in its closed end position is located near the axis of rotation. Like from the Fig. 3b is apparent, a sudden change in the force F (and the current I - see Fig. 3c ) avoided in the embodiment according to the invention. Rather, the curved region 9 results in that the point 10, at which the lever body 3 touches the movable furniture part 8, can move in the direction of the free lever end 4 during the ejection of the movable furniture part 8. This leads to a continuous enlargement of the power arm r.

This effect also occurs in the embodiment according to the invention Fig. 4a on. Since in this embodiment, the point 10 is located at the beginning a little further away from the axis of rotation as in the embodiment according to Fig. 3a , the initial force F is slightly lower (compare Fig. 3b and 4b ).

In the Fig. 5a another embodiment of the invention is shown. Again, can be in the Fig. 5b and 5c recognize the advantageous force or current profile caused by the inventive design of the lever body 3.

Fig. 6a shows a further embodiment according to the invention, in which the ejection device 1 according to Fig. 5a is used. In addition, a projecting area 11 is formed on the movable furniture part 8, which cooperates with the curved area 9 of the lever body 3. In this embodiment, a projecting portion 11 is attached to the rear wall of the drawer. The area 11 comprises a roller 7. This measure means that the point 10 at which the force is exerted by the lever body 3 on the movable furniture part 8, with respect to the movable furniture part 8 is not changed substantially during the entire ejection process. As in the Fig. 6b and 6c shown, after an initial peak in the force F and the current I leads to a particularly advantageous uniform course of the force F and the current I.

In Fig. 7 is exemplary of all other embodiments of the invention, the device 1 according to Fig. 5a shown in the state in which the lever 2 is in its maximum twisted position.

Representing all other embodiments is in Fig. 8 the embodiment according to Fig. 7 shown in a perspective view. The housing 5 of the ejection device 1 can be fastened via sound-damping regions 12 and a fastening screw 13 on the carrier element 6.

In general, it can be said that the advantageous effects of the invention as defined in claim 1 already occur when at least one of the free-lever end and the rotation axis spaced curved portion 9 is provided. Of course, in addition, as shown in all embodiments, also further curved portions 14 may be provided, which may well extend to the free end of the lever 4 and / or to the axis of rotation. However, this is not absolutely necessary.

In the Fig. 9a and 9b a further advantage of the ejection device according to the invention is shown schematically. This advantage is relevant if the ejector is provided with a touch-latch functionality. In this case, in the closed end position of the movable furniture part 8, a clearance between the furniture part 8 and the furniture body, so that the furniture part 8 can be pressed in the direction of the furniture body. This is registered by a sensor and reported to a drive control unit. The Drive control unit activates the drive unit in response thereto. The ejection device then pushes out the movable furniture part 8.

Fig. 9a refers to the in Fig. 1a illustrated lever 2, while in Fig. 9b schematically the situation for the lever 2 of the invention Fig. 3a is shown.

Shown are each the axis of rotation 15 and the power arm r for two positions of the lever 2. In Fig. 9a the positions differ by an angle μ 'and in Fig. 9b by an angle μ. The different positions are due to the fact that a not shown movable furniture part 8 has been moved in its closed end position by the distance X in the direction of the furniture body.

The angle change μ 'or μ is thus effected by the path change X. If the ejection device 1 is now designed in such a way that the angular change μ 'or μ can be detected by the ejection device (for example by a rotary potentiometer arranged on the rotation axis 15), the impressions of the movable furniture part 8 can be triggered to trigger the ejection process (touch-latch Functionality). It can be seen that in the case of a relatively large force arm r according to the prior art, only a small angular change μ 'is effected ( Fig. 9a ).

In contrast, one recognizes in Fig. 9b in that, in the case of a small force arm r, the same path change X is associated with a far greater angular change μ. In a lever 2 according to the embodiment of the invention can therefore be detected by pressing the movable furniture part 8 use request of a user with greater certainty, since the size to be detected μ is greater than μ '.

Claims (10)

1. An ejection device (1) for a movable furniture part (8) comprising an electric actuator and a lever drivable by the actuator for transferring force to the movable furniture part (8), wherein the lever (8) has a lever body (3) which is pivot-mounted within limits around a fulcrum point (15), on the one hand, and which, on the other hand, has a free lever end (4) and wherein said lever body (3) has a curved section (9) situated at a distance from the fulcrum and said free lever end (4), characterised in that the curved section (9) is formed such that, with the ejection device (1) fitted, the point (10) at which said lever body (3) touches said movable furniture part (8) can change from the vicinity of the fulcrum (15), when pushing said movable furniture part (8), towards said free lever end (4) so as to achieve a uniform transition in the moment arm (r).
2. An ejection device in accordance with claim 1, characterised in that said curved section (9) is arc-shaped.
3. An ejection device in accordance with one of claims 1 or 2, characterised in that a sensor, preferably a rotary potentiometer, is fitted to capture the angular position of said lever (2).
4. An ejection device in accordance with claim 3, characterised in that the signals from said sensor can be transmitted to an actuation control unit and that the actuator for said ejection device (1) is activated by the actuation control unit.
5. A furniture item with

   - a furniture part (8) movable from a closed end position and located in or on a furniture body and

   - an ejection device (1) comprising a lever (2) for transferring force to the movable furniture part (8), wherein the lever (8) has a lever body (3) which is pivot-mounted within limits around a fulcrum point, on the one hand, and which, on the other hand, has a free lever end (4) and wherein said lever body (3) has a curved section (9) situated at a distance from the fulcrum,
   wherein the ejection device (1) is arranged on the furniture body in such a way that the lever body (3) can rest with its curved section (9) on said movable furniture part (8) when said movable furniture part (8) is in its closed end position,
   characterised in that point (10) at which said lever body (3) touches said movable furniture part (8) in the closed end position is located more than half of the length of said lever body (3) away from said free lever end (4).
6. A furniture item in accordance with claim 5, characterised in that a raised area (11) is formed on the movable furniture part (8) which interacts with the curved section (9) on the lever body (3).
7. A furniture item in accordance with claim 6, characterised in that the raised area (11) comprises an idler roller (7) arranged on the movable furniture part (8).
8. A furniture item in accordance with one of claims 5 to 7, characterised in that the movable furniture part (8) is a drawer, a lid or a door.
9. A furniture item in accordance with claim 8, characterised in that the lever (2) rests on the rear wall of the drawer with the latter in its closed end position.
10. A furniture item in accordance with claim 8, characterised in that the lever (2) rests on the lid leaf or door leaf when either is in its closed end position.

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