DK3207829T3 - Furniture drive with an electric motor - Google Patents

Description

The invention relates to an electromotive furniture drive with a linearly movable slide as well as a driving lever, operatively connected with the slide, that is swiv-ellable about a swivel shaft connected with the furniture part to be moved, wherein the driving lever has at least two lever parts offset to each other that come into contact with corresponding contact areas of the slide.

Electromotive furniture drives are normally provided with a drivable actuating spindle as well as a spindle nut lockable against rotation on this, with which the slide can be moved back and forth depending on the direction of rotation of the actuating spindle. Alternatively, it is also possible to drive the spindle nut, which results in the actuating spindle moving back and forth thus actuating the slide.

In an electromotive furniture drive of the mentioned type (DE 269 07 493 U1), the driving lever has two lever arms positioned at an angular offset relative to each other and, in addition, offset to each other in the direction of its rotational axis that, when the slide moves, subsequently come into contact with the contact surfaces provided on the slide. Such a structure has already proven effective as due to this type of design of the fluctuation range of the effectively transmitted torque is significantly decreased.

In addition to these advantages, the invention shall have the objective to adjust the fluctuation range of the torque to be transmitted to near zero while achieving a good force distribution at the same time.

According to the invention, this objective is solved by the contact areas of the slide having such a curved guide that the lever sections remain in permanent contact with the contact areas of the slide during a linear movement of the slide.

The invention largely avoids load peaks for the threaded spindle, the spindle nut as well as the bearings, and the invention creates an extremely simple and cost effective structure. The lever sections remain in permanent contact with the linearly moving slide during the entire movement process, wherein the force to be transmitted is distributed onto all the lever sections or all the contact surfaces.

Preferably, three lever sections are provided on the driving lever that cooperate with corresponding contact areas of the slide. The force to be transmitted is distributed simultaneously onto all three lever sections.

The two lateral lever sections of the driving lever appropriately have, as a whole, the same width as the central lever section, so that a good symmetry for the force distribution is achieved.

In a preferred embodiment, the central lever section provided on the driving lever projects further than both its lateral lever sections, wherein the central contact area provided on the slide is set back with respect to its lateral contact areas, so that the central lever section of the driving lever can engage between the two lateral contact areas of the slide. However, it is essential that at least a first contact area of a first lever section of the driving lever is set back with respect to another contact area of another lever section.

In the area of its contact end, the slide can be designed as an enlarged head and the two lateral contact areas can be designed as projecting legs.

The engagement of the projecting lever section of the driving lever is effected in a positive locking manner between the two lateral legs of the slide, so that no lateral clearance may occur.

Such a structure provides additional support for the linear movement of the slide. The two lateral lever sections of the driving lever are appropriately designed congruent to each other enabling a good symmetry of the force path.

The contact areas provided on the slide or the slide head are preferably designed as curved guides, wherein the curved guide provided on the set back central contact area of the slide or of the slide head is concave, while the curved guides provided on the lateral contact areas are designed convex.

Appropriately, the lever sections of the driving lever are designed at their contact areas, where they abut the curved guides of the slide, as rounded tabs that slide along the curved guides of the slide when the slide is moving.

It is particularly appropriate that the convex curved guides provided at the lateral contact areas of the slide are inclined off the swivel shaft, while the concave curved guide designed at the central contact area of the slide is inclined towards the swivel shaft. This measure allows to completely eliminate the transverse forces that act on the lever sections of the driving lever when the slide is moving, so that a harmonic force path is possible.

The inventive structure is particularly suitable for such pieces of furniture where the furniture parts to be controlled, such as, for example, the head or foot part of a hospital bed, automatically swivel back to their original position due to gravity when the slide moves back. However, this is not the case with various furniture structures, so that also the backward movement to the original position must specifically occur under traction.

For this purpose, supports are provided on the slide head that remain connected to the driving lever when the slide moves back.

The support is appropriately a transverse pin that extends through the two lateral legs of the slide as well as through the central projecting lever section of the driving lever, wherein elongate holes in which the transverse pin is guided are provided in the two lateral legs of the slide head. The elongate holes ensure compensation when the central lever section of the driving lever is displaced along the curved guide of the slide head.

In one embodiment, at least a first contact area of at least one lever section of the driving lever can be provided with a pin or with a laterally projecting spigot. It is essential in this embodiment that at least one pin or at least one spigot is arranged in an elongate hole or alternatively in a recess of the slide, wherein the recess is designed as a curved path and follows the contour of the curved guide.

In another embodiment, each lever section can have a pin or spigot-like projections. The above mentioned spigots and spigot-like projections are positioned at right angle to the movement axis of the slide.

The inventive electromotive furniture can appropriately be used for designing a furniture drive system that is equipped to provide different drives that are each suitable for adjusting movable parts of a furniture, such as a chair, wherein the furniture drive has a housing in which an arrangement comprising an electric motor, a spindle drivable by the electric motor, a slide linearly displaceable through the spindle in a longitudinal direction, and a drive element is arranged. Such different drives can be used, for example, for different pieces of furniture or at different movable furniture parts of the same furniture. The furniture having said parts movable with respect to each other can be, for example, seating furniture or lying furniture, for example beds, chairs, sofas or bedsprings. These drives are designed to be attached to a first furniture part of a furniture with their housing and to be attached to a second furniture part of the furniture with their drive element, wherein the two furniture parts are movable with respect to each other. Upon actuation of the electric motor, the spindle is caused to rotate generating a linear movement of the slide along the longitudinal direction, wherein the slide is operatively connected with the drive element. This operative connection provides a force transmission from the slide to the drive element during a movement of the slide along the longitudinal direction. The operative connection is thus designed to cause a movement of the drive element upon a linear movement of the slide along the longitudinal direction. In some embodiments of a furniture drive system, the slide and drive element are designed corresponding to each other in such a way that the linear movement of the slide causes a linear movement of the drive element. In some embodiments of a furniture drive system, that are particularly relevant for the present invention, the slide and drive element are designed corresponding to each other in such a way that a linear movement of the slide causes a rotation of the drive element around a rotational axis.

Various possibilities are known to the person skilled in the art to provide a coupling between electric motor and spindle as well as between spindle and slide in such a way that the spindle is drivable via the electric motor and the slide is driv-able via the spindle. In one embodiment of a furniture drive system known to the person skilled in the art the spindle is connected with the electric motor in such a way that upon actuation of the electric motor, the spindle is caused to rotate. For this purpose, the spindle may be connected with the rotor of the electric motor, for example. In the known embodiment of a furniture drive system, the coupling between spindle and slide can be provided in such a way that the slide has a spindle nut or a threaded hole in which the spindle engages, wherein the slide is guided in the housing in a rotationally fixed manner, so that a rotation of the spindle causes a displacement of the slide along the longitudinal direction. In another known embodiment of a furniture drive system, a spindle nut is connected with the electric motor, which upon actuation of the electric motor, is caused to rotate. The spindle is connected with the slide in a rotationally fixed manner, so that a rotation of the spindle nut causes a displacement of spindle and slide along the longitudinal direction. Various embodiments of slides and correspondingly designed drive elements are known to the person skilled in the art, wherein the corresponding design of slide and drive element provides the operative connection between slide and drive element. For example, embodiments are known to the person skilled in the art in which an operative connection between slide and drive element is provided by section-wise engagement of slide and drive element, or an embodiment in which an operative connection is provided by providing two adjacent sections of slide and drive element allowing a force transmission from the slide to the drive element.

With generic systems, it was found to be problematic that such systems need to provide different drives for different purposes which requires a different design of the drives. For example, a drive that is to be used for height adjustment of a chair, has to meet entirely different requirements compared to a drive that is to be used for tilting the chair’s backrest in respect to the seat. A drive meeting different requirements can in most cases only be realized at very high cost. The provision of different drives that are each designed differently to each meet special requirements is also costly as both, the manufacturing cost and the storage cost for the provision of the differently designed drives are high.

This is where the design of a furniture drive system according to the invention comes in, by proposing a system for providing different drives for adjusting parts of a furniture movable with respect to each other, which at least partly eliminates at least one disadvantage of known systems. For this purpose, a furniture drive system is proposed with a base group comprising at least the housing and particularly the electric motor of the drive to be provided. The system further comprises at least two different replacement groups, wherein each replacement group comprises a drive element assigned thereto and a slide assigned thereto. According to the invention, each drive provided by the system is formed by the base group and one of the different replacement groups. Thus, all the different drives provided by the system each comprise an identical base group as well as one of the different replacement groups, wherein the replacement groups of the different drives are designed differently. Preferably, the longitudinal direction, in which the slide is linearly displaceable, is defined by the base group and thus the same for each drive provided by the system. According to the invention, at least some of the drive elements that are assigned to different replacement groups are each designed differently with respect to each other and/or at least some of the slides that are assigned to different replacement groups are each designed differently with respect to each other. In particular, the different replacement groups may each comprise an assigned slide, wherein the slides that are assigned to different replacement groups are each designed differently. In particular, the different replacement groups may each comprise an assigned drive element, wherein the drive elements that are assigned to different replacement groups are each designed differently. The respective slide of the relevant replacement group is specifically provided corresponding to the respective drive element which may allow for a design of the slide that is as simple as possible and a design of the operative connection between drive element and slide that is as specific as possible. It is understood that the slides of the different replacement groups are designed corresponding to the base group, so that the slides of the replacement group are linearly displaceable through the spindle in the longitudinal direction.

The above electromotive furniture drive initially described can be comprised by the inventive furniture drive system in at least one of its embodiments, i.e. such an inventive furniture drive system is designed such that at least one embodiment of the electromotive furniture drive described above can be formed, i.e. built therefrom. The driving lever specified with reference to the above electromotive furniture drive initially described represents the drive element or section of the drive element of the inventive furniture drive system or is synonymous therewith.

In other words, the invention further relates to the use of an inventive system for the provision of an above electromotive furniture drive initially described, wherein for the provision of the drive, the base group of the system is combined with one of the different replacement groups.

It should be expressly understood that the inventive furniture drive system, also as further specified or developed in the following, can be, on the one hand, designed such that at least one embodiment of the above electromotive furniture drive initially described can be built therefrom. On the other hand, it is stressed that in addition, the inventive furniture drive system, also as further specified in the following, is disclosed as an independent inventive subject matter and is to be considered as such.

In one embodiment of the furniture drive system, the base group comprises the spindle that is designed identically for all the drives provided by the system, wherein the different slides of different replacement groups each have an identical coupling point for coupling them to the spindle, for example, a spindle nut or a screw flange for screwing them to the spindle. In one embodiment of the furniture drive system, each replacement group comprises a spindle assigned thereto that is designed corresponding to the slide assigned thereto. It can be preferably provided that at least one spindle assigned to a first of the replacement groups is different from a spindle assigned to a second of the replacement groups. It is understood that the spindles of the different replacement groups are designed corresponding to the base group, so that the spindles are drivable via the electric motor that is preferably comprised by the base group.

The inventive system ensures that, at manufacturing and storage costs that are as little as possible, a plurality of different drives that are each designed differently and meet different requirements are provided. The invention contributes to this in that all the different drives have an identical housing and particularly an identical electric motor. In return, the adjustment of the respective drive is realized via the replacement group. For example, the drive element can be specifically designed according to the furniture part to be moved, for example, as a lever arm welded to a transmission shaft, as a gear wheel that is connected with a transmission shaft in a rotationally fixed manner or as a projection that is provided in a furniture part to be displaced in the longitudinal direction. Accordingly, a different operative connection can be provided between slide and drive element, as required, by specifically providing different slide drive elements arrangements. For example, for this purpose, the slide may have a front end, a recess and/or a rack section, wherein, depending on the drive element, in a slide drive element arrangement, the lever arm abuts the front end of the slide, the gear wheel engages in the rack section or the projection is arranged in the recess.

In one embodiment of the inventive system, at least one of the replacement groups, particularly several of the replacement groups, particularly all of the replacement groups, comprises a slide drive element arrangement that is designed such that a linear movement of the slide along the longitudinal direction causes the drive element to rotate around a rotational axis. As explained above, the slide drive element arrangement can be designed appropriately for this. For example, the slide can have a front end and the drive element can be designed in the manner of a lever having a lever arm abutting the front end of the slide. For example, the drive element may have first gear elements and the slide second gear elements, wherein the second gear elements are arranged in a linear arrangement on the slide whereas the first gear elements are arranged in a circular arrangement on the drive element, wherein the rotational axis is particularly in the center of the circular arc of the circular arrangement. For this purpose, the first gear elements can be designed as recesses and the second gear elements as projections or the first gear elements as projections and the second gear elements as recesses. For example, the drive element can be designed in the manner of a gear wheel that engages in a rack section of a slide.

In one embodiment, the system comprises at least one replacement group designed as a push drive group and/or at least one replacement group designed as a pull drive group and/or at least one replacement group designed as a pull-push drive group. In this context, it has to be taken into account that different basic types of drives exist. In a push drive, the spindle, slide and drive element are designed with respect to each other in such a way that the operative connection between the drive element and slide allows force transmission in one direction only, that is a unidirectional force transmission, along the longitudinal direction, wherein this force transmission is only allowed in such a direction, in which the spindle applies pressure to the slide. In a pull drive group, the drive element, slide and spindle are designed corresponding to each other is such a way that, as in the push drive group, only a unidirectional force transmission from the slide to the drive element along the longitudinal direction is allowed, wherein such a force transmission is only possible in a direction, in which the spindle applies a pull force to the slide. In a push drive provided by the system, in which the longitudinal direction is defined by the base group, a force transmission from the slide to the drive element as intended is thus only possible in a positive direction along the longitudinal direction, whereas in a pull drive a force transmission from the slide to the drive element as intended is only possible in a negative direction along the longitudinal direction. In a pull-push drive, the spindle, slide and drive element are designed corresponding to each other in such a way that a bidirectional force transmission and thus a force transmission in the positive and in the negative direction along the longitudinal direction from the slide to the drive element is enabled. Therefore, different basic drive group types exist, namely the basic drive group types push drive group, pull drive group, and pull-push drive group. By comprising at least two replacement groups designed as different basic drive groups types, the system, in the particularly advantageous embodiment described, allows the provision of drives having identical essential components, particularly housing and electric motor, and simultaneously meeting different requirements by having different replacement groups of different basic drive group types.

For example, for adjusting the height of the seat of a chair, preferably a drive having a push drive group as a replacement group is used, whereas for adjusting the incline of the back rest with respect to the seat for a chair preferably a drive having a pull-push drive group as a replacement group is provided.

In one embodiment of the furniture drive system, at least one of the replacement groups is designed as a push drive group, wherein the drive element assigned thereto is designed in the manner of a lever with a transmission section and at least one lever arm. A transmission shaft is securable at the transmission section in a rotationally fixed manner, through which a rotation of the drive element can be transmitted to a furniture part. The lever arm abuts a front end of the assigned slide to provide a unidirectional operative connection between the slide and the drive element in the longitudinal direction. One coupling end of the slide, through which the slide is connected with the spindle, points in a positive longitudinal direction of the spindle, wherein the front side, which the lever arm of the drive element abuts as intended to provide an operative connection, points in a negative direction along the longitudinal direction. This embodiment of the inventive system thus allows the provision of a push drive, the design of which is as simple and simultaneously as robust as possible.

In one embodiment of the furniture drive system, at least one of the replacement groups is designed as a pull drive group, wherein the drive element assigned thereto is designed in the manner of a lever with a transmission section and at least one lever arm. A transmission shaft is securable at the transmission section in a rotationally fixed manner, through which a rotation of the drive element can be transmitted to a furniture part. The lever arm abuts a front end of the assigned slide to provide a unidirectional operative connection between the slide and the drive element in the longitudinal direction. The front end of the slide that the lever arm of the drive element abuts as intended to provide the operative connection, and a coupling end of the slide, through which the slide is connected with the spindle, each point in the same direction along the longitudinal direction. In this way, the inventive system provides, in a particularly easy manner, a robust pull drive where the spindle can cause a force-resilient displacement of the slide along the longitudinal direction under application of a pull force, while the lever arm of the drive element abuts the front end of the slide. Particularly preferably, for this purpose, the slide may have a recess, in which the lever arm of the drive element is arranged, wherein the front end is particularly designed as the internal surface of the recess which is spaced furthest apart from the spindle.

In one embodiment of the furniture drive system, at least one of the replacement groups is designed as a pull-push drive group, wherein the drive element assigned thereto is operatively connected with the slide assigned thereto through a gearing. Particularly the drive element has first gear elements arranged in a circular arrangement and corresponding with a second gear elements arranged in a linear arrangement on the assigned slide. The linear arrangement is preferably parallel to the longitudinal direction. Preferably, the second gear elements are spaced apart from each other in the longitudinal direction. In the described embodiment, the system is suitable, by combining the pull-push drive group with the base group, to provide a pull-push drive, where a bidirectional operative connection between the slide and drive element is provided, so that a force transmission in a positive and in a negative direction along the longitudinal direction between the slide and the drive element may occur. Accordingly, in a drive where the replacement group comprises a slide drive element arrangement designed to translate a linear movement of the slide into a rotation of the drive element via the operative connection between the slide and the drive element, a force-resilient rotation of the drive element in a positive and in a negative rotation direction around the rotational axis may be enabled. Such a pull-push drive can particularly preferably be used for adjusting the inclination angle of a back rest with respect to a seat.

In one embodiment of the furniture drive, at least one of the replacement groups is designed as a pull-push drive group, wherein the drive element assigned thereto is designed in the manner of a lever with a transmission section and with at least one lever arm. A transmission shaft is securable at the transmission section in a rotationally fixed manner, through which a rotation of the drive element can be transmitted to a furniture part. The lever arm is arranged in a recess of the slide to provide a bidirectional operative connection between the slide and the drive element in a longitudinal direction. The lever arm of the drive element is thus designed to abut a first front end of the slide to provide an operative connection acting in a positive direction along the longitudinal direction and to abut a second front end of the slide to provide an operative connection acting in a negative direction along the longitudinal direction. The two front ends of the slide are arranged opposite to each other in the longitudinal direction. For this purpose, the lever arm can comprise two partial lever arms, for example, wherein a first partial lever arm abuts the first front end and a second partial lever arm the second front end of the slide to provide the respective operative connection.

In one embodiment of the furniture drive, the slide comprises a transmission element and a drive element, wherein each replacement group of a plurality of different replacement groups, particularly each replacement group of the different replacement groups, each has an identical drive element of the slide, wherein the corresponding replacement groups each differ at least in their assigned drive elements of their slides and their assigned drive elements. In this embodiment, it is ensured that different replacement groups have different slide drive element arrangements, wherein the slides of these different replacement groups each only differ in their transmission elements. Thus, a very cost-efficient variation of the replacement groups may be enabled on the one hand. On the other hand, a very good adaptation of the operative connection between the drive element and the slide may thus be enabled while a coupling between the slide and the spindle that is as good as possible is easily maintained. The transmission element and the drive element of the slide can be connected with each other via a plug connection or a threaded connection, for example.

The invention further relates to the use of an inventive system to provide a drive, wherein for the provision of the drive the base group of the system is combined with one of the different replacement groups. The invention further relates to a drive for adjusting parts of a furniture that are movable with respect to each other, wherein the drive is provided by the inventive system. The invention further relates to a drive for adjusting parts of a furniture that are movable with respect to each other, wherein the drive is provided by the use of the inventive system according to the invention. The invention further relates to a furniture, particularly a seating or lying furniture, particularly a chair, having at least one inventive drive, wherein the furniture comprises two furniture parts that are movable with respect to each other. The housing of the drive is arranged on a first of the two furniture parts movable with respect to each other and the drive element on a second of the two furniture parts of the furniture movable with respect to each other. Particularly preferably, the housing is secured to the first furniture part in a fixed position and the drive element is secured to the second furniture part in a fixed position. This ensures that a movement of the drive element relative to the housing causes a direct movement of the two furniture parts with respect to each other. In one embodiment of the inventive furniture, it is provided that the housing of the drive always remains in a fixed position, while the drive element rotates with the second furniture part relative to the first furniture part and the housing. In one embodiment, it is provided that the drive element and the second furniture part always retain their position, while the housing and the second furniture part can be adjusted by the drive relative to the stationary second furniture part or drive element. In another embodiment, it is provided that, when adjusting the two furniture parts movable with respect to each other, both furniture parts and thus the housing and drive element change their position.

The invention will be explained in the following by describing some embodiments with reference to the accompanying drawings. In the drawings:

Fig. 1: shows, in a perspective, exploded illustration, a connection between a slide and a driving lever,

Fig. 2: shows the same illustration as in Fig. 1 from a slightly different view,

Fig. 3: shows the same illustration as in Fig. 2, in which the slide directly abuts the driving lever,

Fig. 4: shows, on a larger scale, the detailed curved path of the contact surfaces, namely as a section along line IV of Fig. 3, and

Fig. 5: shows a side view of an embodiment of an inventive furniture drive with an integrated return mechanism,

Fig. 6: shows, in a schematic principal illustration, a cross section of an embodiment of an inventive drive,

Fig. 7: shows, in a schematic principal illustration, a cross section of an embodiment of an inventive drive;

Fig. 8: shows, in a schematic principal illustration, a cross section of an embodiment of an inventive drive;

Fig. 9: shows, in a perspective view, the slide 105 and the drive element 106 of the drive operatively connected with it according to Fig. 8;

Fig. 10: shows an arrangement of a slide 105 and a drive element modified with respect to figure 9;

Fig. 11: shows a drive element and a corresponding transmission shaft;

Fig. 12: shows a cross section perpendicular to the rotational axis of an arrangement, comprising drive element and transmission shaft according to Fig. 11; and

Fig. 13: shows an arrangement, comprising drive element and transmission shaft in another embodiment.

Fig. 1 shows a swivel shaft 1 connected with a furniture part to be moved, for example, the head or foot part of a hospital bed or the back rest of a chair. A driving lever 2 fastened to the outer surface of the swivel shaft 1 is provided at the swivel shaft 1. A slide 3 drivable by means of an electric motor (not shown in the drawing) via a reduction gear, a threaded spindle as well as a spindle nut serves for swiveling the swivel shaft 1.

The driving lever 2 abuts the enlarged head 4 of the slide 3 in operation, as, for example, shown in Figs. 3 and 4 of the drawings. If the slide 3 in Fig. 3 is driven in a forward direction, i. e. moves towards the left in the drawing, then the driving lever 2 is also swiveled to the left and moves the swivel shaft 1 in the clockwise direction, which, for example, results in the head part of a hospital bed being raised.

If the slide 3 moves backwards and the driving lever follows the slide 3, then the swivel shaft 1 moves in the anti-clockwise direction and swivels the head part of the bed to the original position. The head part is lowered by the weight of the head part, i. e. due to gravity. Therefore, in the present case, the slide 3 only operates in push operation.

If the corresponding furniture part cannot return to its original position due to its gravity, then a constraining guide as well as a so-called pull-push drive are required. This will be described further below in connection with Fig. 5.

The special features of the inventive structure are the design of the driving lever 2 as well as the design of the slide head 4 adapted to the driving lever 2.

The driving lever 2 has three lever sections, namely a central lever section 5 as well as two lever sections 6 and 7 arranged laterally with respect thereto.

The central lever section 5 is designed longer than the two lateral lever sections 6 and7, and it is also designed wider then these. Preferably, the width of the central lever section 5 corresponds to the two lateral lever sections 6 and 7 of equal width, as a whole. The two lateral lever sections 6 and 7 are designed congruent to each other.

The lever sections 5, 6 and 7 cooperate with corresponding contact areas 8 and 9 that are designed at the lever head 4. The central contact area 8 is arranged slightly reset and serves for abutment of the central lever section 5, while the two lateral lever sections 6 and 7 abut the contact areas 9 of the slide head 4.

All the three lever sections 5, 6, 7 permanently abut the corresponding contact areas 8, 9 of the slide head 4.

In their contact areas, the lever sections 5, 6, 7 are provided with rounded tabs 10, 11, 12 that slide along the contact areas 8, 9 of the slide head 4 when the slide 3 is moving.

The contact areas 8, 9 provided on the slide head 4 are designed as curved guides. The curved guide designed at the central, reset contact area 8 has a concave shape and the curved guides designed at the outer contact areas 9 a convex shape. The two lateral contact areas 9 are designed at lateral legs 13,14 of the slide head 4, wherein the two legs 13, 14 include the central contact area 8 between them. The central lever section 5 of the driving lever 2 engages between the two lateral legs 13, 14 provided at the slide head 4 in a positive locking manner and abuts the central contact area 8 of the slide head 4.

The two outer convex curved guided designed at the lateral legs 13, 14 are inclined towards the swivel shaft 1, while the concave curved guides designed at the central contact area 8 are inclined off the swivel shaft 1.

Due to these curved guides, it is possible for the forces acting on the lever sections 5, 6, 7 of the driving lever 2 when the slide 3 is moving to eliminate each other.

The embodiment shown in figures 1 to 4 exclusively represents a push drive, where, when the slide 3 moves backwards, due to the gravity of the relevant furniture part, said furniture part automatically swivels back to the original position retaining the contact between the driving lever 2 and the slide head 4.

If such a reset effect is not possible or only to a certain extent, as, for example, with a back rest of a chair, then a constrained pull-push drive can be provided, as shown in Fig. 5.

To obtain such a constraining guide, the driving lever 2 must be fixedly coupled to the slide 3 or the slide head 4. However, with respect to their geometry, the driving lever 2 as well as the slide head 4 can be designed in the same manner, as in the exemplary embodiment according to Fig. 1 to 4, so that the described advantageous features and the advantageous cinematics are retained.

To achieve such a required constraining guide, supports must be provided at the slide head 4 that remain connected with the driving lever 2 when the slide 3 is moved backwards. For example, a transverse pin is provided as a support that extends transversely through the front area of the lever section 5 as well as through the two lateral legs 13 and 14 of the slide head.

To obtain the desired sliding mechanism of the rounded tabs 10, 11, 12 of the lever sections 5, 6, 7 at the contact areas 8, 9 of the slide head 4, the transverse pin 15 is guided in elongate holes 16 in the lateral legs 13 and 14, so that the desired force path in the contact areas remains fully preserved, as it is shown and described in the exemplary embodiment according to Fig. 1 to 4.

In the figures 6-8, different drives 101 are shown that are each provided by the same embodiment of an inventive system. The inventive system comprises a base group having a housing 108, an electric motor 109, a motor drive 104, a spindle nut 103 and a s spindle 102. Via the electric motor 109, the motor drive 104 is caused to rotate, which results in the spindle nut 103 being driven and thus being caused to rotate, which results in the spindle 102 being displaced along the longitudinal direction, as the spindle 102, in the drives 101 provided by the inventive system, is held in the housing 108 in a rotationally fixed manner. For this purpose, in all different drives provided by the inventive system, the spindle 102 is connected with the slide 105 in a rotationally fixed manner.

The embodiment of the inventive system provided by the drives 101 shown in the figures 6-8 comprises three different replacement groups. A first drive 101 with a first replacement group is shown in Fig. 6, a second drive 101 with a second replacement group is shown in Fig. 7, and a third drive 101 with a third replacement group is shown in Fig. 8. The different replacement groups each have a slide 105 and a drive element 106. The slides 105 of all different replacement groups each have a coupling end to which the spindle 102 of the base group of the system can be coupled, wherein in the described embodiment of the inventive system, a screwed connection of the spindle I02 with the slide 105 is provided.

In the described embodiments of the inventive system, the replacement groups associated with the figures 6 to 7 have a slide drive element arrangement that is designed such that a linear movement of the slide 105 in the longitudinal direction X causes a rotation of the drive element 106 around a rotational axis. The drive 101 provided by the inventive system shown in Fig. 6 is designed as a push drive. This drive 101 thus has a replacement group that is designed as a push drive group. This replacement group has a drive element 106 that is designed in the manner of a lever having a transmission section and a lever arm 166. A feedthrough is provided in the transmission section that is designed to accommodate a transmission shaft that is held in the feedthrough in a rotationally fixed manner. For this purpose, a transmission shaft, here also referred to as a swivel shaft, is to be provided that has a cross section corresponding to the cross section of the feedthrough of the transmission section of the drive element 106. As can be seen, the drive element of the embodiment according to the figures 1 to 3 is, in contrast, designed as a driving element or as a driving lever that is fixed, for example, welded, to the transmission shaft or the swivel shaft. Apart from these differences, the drive of the figures 1 to 3 and the drives of the figure 6 are of identical design.

Turning back to the embodiments of Fig. 6 to 8, the lever arm 166 has two partial lever arms 661, 662. The slide 105 of the replacement group of the drive 101 according to Fig. 6 hast to front ends 551,552. The two front ends 551,552 each point in a positive direction along the longitudinal direction X, while the coupling end to which the spindle 102 is coupled points in a negative direction along the longitudinal direction. The cooperation of the front ends 551,552 with the partial lever arms 661 ,662 ensures a unidirectional force transmission from the slide 105 to the drive element 106. The two partial lever arms 661, 662 and the two front ends 551, 552 are designed corresponding to each other such that a very large torque can be applied to the transmission section of the drive element 106 by the slide 105 over a very large displacement range of the slide 105 along the longitudinal direction X.

The drive 101 provided by the described embodiment of the inventive system shown in Fig. 7 differs from the drive 101 according to Fig. 6 substantially in the arrangement of the drive element 106 and the design of the slide 105. The slide 105 of the drive 101 according to Fig. 7 has a recess in which the lever arm 166 of the drive element 106 is arranged. The slide 105 has two front ends 551,552 that each point in the same direction, namely in the negative direction along the longitudinal direction X, like the coupling end through which the slide 105 is connected with the spindle 102. Accordingly, the drive 101 according to Fig. 7 is designed as a pull drive and the replacement group of the drive 101 according to Fig. 7 is designed as a pull drive group.

The drive 101 provided by the inventive system shown in Fig. 8 is designed as a pull-push drive. In this drive 101, the replacement group is designed as pull-push drive group. The drive element 106 is operatively connected with the slide 105 through a gearing. For this purpose, the drive element 106 has teeth 161 that engage between rod-like elements 51 laterally provided on the slide 105. In the drive 101 according to Fig. 8, a bidirectional operative connection between the slide 105 and the drive element 106 is thus provided so that the slide can transmit a force to the drive element 106 both, in a positive and in a negative direction along the longitudinal direction X.

In Fig. 9, an arrangement comprising drive element 106 and slide 105 of an embodiment of an inventive drive 101 is shown schematically. In the embodiment shown in Fig. 9, the drive element 106 has two gearing sections. A first group of teeth 161 is provided on a first gearing section, a second group of teeth 161 is provided on a second gearing section. The slide 105 has a drive section 153, a first group of rod-like elements 151 being provided on one side thereof with respect to a direction along the rotational axis and a second group of rod-like elements 151 being provided on a second side thereof with respect to a direction along the rotational axis. The rod-like elements 151 are each designed cylindrical and have a circular cross section. The teeth each have a bulge. In the embodiment according to Fig. 9, the drive section 153 of the slide 105 is arranged between the two gearing sections of the drive element 106 with respect to a direction along the rotational axis, wherein the gearing sections of the drive element 106 sectionally overlap with the slide 105 along the transverse direction Y and along the longitudinal direction X. This provides a particularly good guidance of drive element 106 and slide 105 with respect to each other. In addition, the central provision of the drive section 153, at which a spindle 102 can be arranged for driving the slide 105, and the provision of an engaging gearing on both sides of the drive section 103, ensure a particularly uniform force transmission between slide 105 and drive element 106, so that an off-center load on the slide 105 or drive element 106 is possibly avoided. In the embodiment according to Fig. 9, a threaded hole is provided in the drive section 153 of the slide, in which a spindle 102 with a corresponding external thread can engage. Accordingly, a displacement of the slide 106 along the longitudinal axis can be caused through a rotation of the spindle 102.

In Fig. 10, an arrangement of another embodiment of an inventive drive 101 is shown schematically. The arrangement according to Fig. 10 differs from the arrangement according to Fig. 10 essentially in that the drive element 106 in the embodiment according to Fig. 10 has circular projections 163 that are provided laterally on the drive element 106 with respect to a direction along the rotational axis. These circular projections 163, that, in an inventive drive 101, engage in corresponding circular grooves of the housing 108, ensure a particularly good guidance of the drive element 106 in the housing 108.

In Fig. 11, the drive element 106 and the transmission shaft 107 of an embodiment of an inventive drive 101 are shown schematically. It can be seen from Fig. 11 that in the described embodiment, the transmission shaft 107 is designed in the manner of a tube with a round cross section, to which a driving element 171 is fixated in a fixed position. In the presently described exemplary embodiment, the driving element 171 is welded to the round tube. The drive element 106 has a feedthrough 162 having a cross section perpendicular to the rotational axis that corresponds with the shared cross section of pipe and driving element 171. In the described embodiment, the transmission shaft 107, due to the circular cross section of its tube, can be particularly easily supported in a furniture so that the transmission shaft 107 can act as a rotational axis of a furniture part. At the same time, such a cross section of the transmission shaft 107 that can be fixated in a rota-tionally fixed manner to a feedthrough 162 having a corresponding cross section is provided in a particularly easy manner via the driving element 171 welded to the tube of the transmission shaft 107. The fixation in a rotationally fixed manner solely requires inserting the transmission shaft 107 into the drive element 106 through the feedthrough 162 or sliding the drive element 106 onto the transmission shaft 107 along the rotational axis.

In Fig. 12, an arrangement of the drive element 106 and the transmission shaft 107 of an embodiment of an inventive drive 101 is shown schematically. The drive element 106 has a feedthrough 162 having an opening at its top end in the trans-vers direction Y to ensure insertion of the transmission shaft 107 into the feedthrough 162 along the transverse direction Y. The feedthrough 162 further has a section, the sides of which are parallel with respect to each other and parallel to the transvers direction Y. This enables particularly easy insertion of the transmission shaft 107 into the feedthrough 162. In addition, the transmission shaft, as explained in Fig. 12, has a driving element 171, wherein the driving element 171 and the tube of the transmission shaft 107 together form a cross section that corresponds with the cross section of the feed through 162 of the drive element 106 to ensure fixation of the transmission shaft 107 in a rotationally fixed manner relative to the drive element 106.

In Fig. 13, an arrangement comprising the drive element 106 and the transmission shaft 107 of an inventive drive 101 is shown schematically. As explained with respect to Fig. 12, in the embodiment according to Fig. 13, the drive element 106 also has a feedthrough 162 with an opening, into which the transmission shaft 107 can be inserted perpendicularly to the rotational axis. In contrast to the exemplary embodiment according to Fig. 12, in the exemplary embodiment according to Fig. 13, a pin 172 is arranged at the side of the feedthrough 162 that is located opposite to its opening along the transvers direction Y. The pin 172 acts as a driving element of the drive element 106 that extends perpendicularly to the direction of the rotational axis. The transmission shaft 107 is designed as a tube with a round cross section and has a hole that is provided in the transmission shaft 107 perpendicularly to the rotational axis and corresponds with a pin 172 of the drive element 106. This hole acts as a corresponding driving element of the transmission shaft 107. The pin 172 is arranged in the feedthrough, particularly relative to the opening of the feedthrough 162, in such a way that the pin can be engaged with the hole in the transmission shaft 107, while the transmission shaft 107 is inserted into the feedthrough.

From the described exemplary embodiment of an inventive system that is suitable for providing the different drives 101 shown in the figures 6-13 and figures 1 to 5, respectively, it can be seen that the inventive system enables the provision of different drives for different areas of application with a very low manufacturing complexity and at very low costs. Because the inventive system allows to combine an identical base group with different replacement groups in order to provide different drive types.

List of reference numerals 1 Swivel shaft 2 Driving lever 3 Slide 4 Slide head 5 Central lever section 6 Lateral lever section 7 Lateral lever section 8 Central contact area (at slide head 4) 9 Lateral contact area (at slide head 4) 10 Rounded tab 11 Rounded tab 12 Rounded tab 13 Lateral leg (of slide head 4) 14 Lateral leg (of slide head 4) 15 Transverse pin 16 Elongate hole 101 Drive 102 Spindle 103 Spindle nut 104 Motor drive 105 Slide 106 Drive element 108 Housing 109 Electric motor 151 Rod-like elements 161 Teeth 166 Lever arm 551 Front end 552 Front end 661 Partial lever arm 662 Partial lever arm

Claims (14)

Furniture drive with an electric motor and with a linear, mobile slider (3) and an operating rod (2) in contact with the slider (3) operable about a rotatable shaft (1) connected to a furniture part, movable, and wherein the carrier rod (2) has at least two offset rod portions (5, 6, 7) which may come into contact with corresponding contact areas (8, 9) on the slider (3), characterized by, that the contact areas (8, 9) of the shooting means (3) have such a curved guide that the rod sections (5, 6, 7) in connection with the linear movement of the shooting means (3) stay in permanent contact with the contact areas (8, 9) of the shooting means ( 3). Furniture drive with an electric motor according to claim 1, characterized in that the force to be transmitted at each relative position between the slider (3) and the carrier rod (2) is uniformly distributed on all contact surfaces existing between the slider (3) and the carrier rod (2). Furniture drive with an electric motor according to claim 1 or 2, characterized in that at the carrier rod (2) there are three rod sections (5, 6, 7) which can cooperate with corresponding contact areas (8, 9) on the slider (3). Furniture drive with an electric motor according to claim 1, characterized in that two lateral rod sections (6, 7) of the carrier rod (2) together have the same width as a middle rod section (5). Furniture drive with an electric motor according to claim 4, characterized in that the middle rod section (5) of the driver rod (2) projects more than the two adjacent rod sections (6, 7) and it is arranged at the slider (3). the middle contact area (8) with respect to its lateral contact areas (9) is retracted and the middle rod portion (5) of the carrier rod (2) engages between the two lateral contact areas (9) of the slider (3). Furniture drive with an electric motor according to claim 5, characterized in that the slider (3) in the region of its contact end is formed as a head (4) which is made quite wide and that the two contact areas (9) ) is designed as projecting legs (13, 14). Furniture drive with an electric motor according to claim 6, characterized in that the engagement of the projecting rod portion (5) of the carrier rod (2) between the two legs (13, 14) located on the head (4) of the slider is mold-closing. Furniture drive with an electric motor according to one of claims 5 to 7, characterized in that the two side sections (6, 7) located on the driver rod (2) are congruently designed. Furniture drive with an electric motor according to one of claims 5 to 8, characterized in that the contact areas (8, 9) located at the shooting means (3) and the head (4) of the shooting means, respectively, are formed as curved guides and that the curved guide which is positioned at the middle retracted contact area (8) of the slider (3) or the head (4) of the slider, respectively, concave, while the curved guides (9) placed on the adjacent contact areas (8) are convex. Furniture drive with an electric motor according to claim 9, characterized in that the rod sections (5, 6, 7) of the carrier rod (2) at their contact areas with the curved guides of the slider (3) are formed as rounded noses (11, 12). ) which, when moving the slider (3), can slide on the slider (3) along the curved guides. Furniture drive with an electric motor according to claim 9 or 10, characterized in that some convex curved guides provided at the adjacent areas (9) of the slider (3) are inclined away from the rotatable shaft (1), while a concave curved guide at the center contact area (8) of the slider (3), inclined towards the pivot shaft (1). Furniture drive with an electric motor according to claim 11, characterized in that some transverse forces arising during the movement of the slider (3) on the rod sections (5, 6, 7) of the carrier rod (2) mutually cancel each other. Furniture drive with an electric motor according to one of claims 1 to 12, characterized in that there are holders on the sliding head (4) which, in a reciprocating movement of the sliding member (3), remain connected to the carrier rod (2). Furniture drive with an electric motor according to claim 13, characterized in that as a holder is provided a transverse pin (15) extending through the two laterally positioned legs of the sliding head (4) and through the middle projecting rod section (5) of the carrier rod (2) and long holes (16) formed in the two adjacent legs (13, 14) of the slider head (4) into which holes the transverse pin (15) is slidably disposed.