CN107427132B

CN107427132B - Electric furniture drive

Info

Publication number: CN107427132B
Application number: CN201680015550.8A
Authority: CN
Inventors: H·科利姆; W·彼得斯
Original assignee: Dewertokin GmbH
Current assignee: Dewertokin Technology Group Co Ltd
Priority date: 2015-03-13
Filing date: 2016-03-11
Publication date: 2020-05-22
Anticipated expiration: 2036-03-11
Also published as: EP3267844A1; DE202015101318U1; DK3267844T3; EP3267844B1; ES2737749T3; CN107427132A; WO2016146549A1

Abstract

The invention relates to an electromotive furniture drive for adjusting at least one furniture part of a piece of furniture, comprising: at least one drive unit (20) comprising a drive motor (21), a transmission (22) and a spindle drive acting on a pressure slide (25) movable along a movement path. The electromotive furniture drive is characterized in that a base body (251) of the pressure slide (25) is provided with a pressure head (26) mounted in a floating manner.

Description

Electric furniture drive

Technical Field

The invention relates to an electromotive furniture drive for adjusting at least one furniture part of a piece of furniture, comprising: at least one drive unit, which comprises a drive motor, a gear and a spindle drive, which acts on a pressure slide that is movable along a displacement path.

Background

The use of such an electric furniture drive enables an electric adjustment of a furniture part, such as a head or leg part of a slat or a footrest or a backrest of a walking chair. The furniture drive can be designed, for example, as a single drive with one drive unit or as a double drive with two drive units. The dual drive can be mounted in a simple manner on a piece of furniture, for example on a slat of a bed, by: each pivot axis of the piece of furniture is inserted into a respective axle receptacle formed on the furniture drive. For this purpose, the shaft receptacle is usually provided with a cover slide which can be removed in order to insert the pivot shaft into the shaft receptacle with the pivot lever. After the resetting of the covering slide, the entire double drive is fixed on the shaft. The drive units act via their spindle drives independently of one another and cause the presser slide to act on the respective pivot lever in order to adjust the furniture part.

Such a furniture drive with a pressure slide as an output element, which is moved linearly via a spindle drive, is known, for example, from DE 20302139U 1. In this furniture drive, the pressure slide has a substantially cylindrical pressure piece into which the spindle nut is inserted on one side and the pressure plate is placed on the opposite side of the pressure piece. The spindle of the spindle drive engages into the spindle nut and enters the hollow section of the interior of the pressure piece up to the maximum pressure plate. On the outside of the pressure plate there is a pivoting lever of the pivot axis of the furniture part for the adjustment of the furniture part. The pressure element is produced here from a profile rail section with a quadrangular cross section.

A disadvantage of the known pressure slide is that, if the pivot lever is not exactly centered on the pressure slide or if the contact surface of the pivot lever is not oriented parallel to the surface of the pressure plate, a strong tilting moment acts on the pressure slide, which loads the pressure slide and exerts a transverse force on the linear guide of the pressure slide. The transverse forces lead to higher friction and therefore higher wear of the guides. When the contact surface of the pivot lever is oriented non-parallel to the surface of the pressure plate, the contact surface between the pivot lever and the pressure plate becomes smaller, which increases the pressure acting on the contact surface.

Disclosure of Invention

The object of the present invention is therefore to provide an electromotive furniture drive of the type mentioned in the introduction, in which the tilting moment acting on the pressure slide is reduced and in which the largest possible contact surface is formed between the two parts even when the contact surface of the pivot lever is not oriented exactly parallel to the surface of the pressure plate.

This object is achieved by an electromotive furniture drive having the features of the independent claim. Advantageous embodiments and refinements are specified in the dependent claims.

An electric furniture drive of the type mentioned at the outset is characterized in that the basic body of the pressure slide is provided with a pressure head which is mounted in a floating manner. The pressure head mounted in a floating manner compensates for the pivot rod being not precisely oriented and thus increases the contact surface again. The pressure head is arranged in front of or on the base body of the pressure slide. The pressure head can be connected, for example form-fittingly connected, to the pressure head such that it forms a unit with the base body, wherein movement is permitted to compensate for pivot rods which are not oriented exactly parallel. Alternatively, the pressure head can also be coupled only in a force-fitting manner to the base body of the pressure slide in that the pressure head is positioned between the base body and the pivot lever.

It is particularly advantageous if the pressure head is mounted on the basic body of the pressure slide such that it can perform a pivoting movement on a circular path. In this way, both a sliding movement and a pivoting movement can be achieved, which is particularly well suited for angle compensation. The center point of the circular path can be located, for example, on the axis of the spindle.

The combined sliding and pivoting movement can be realized in a structurally simple manner by: the basic body has a convex contact surface and the pressure head has a concave contact surface, so that the basic body and the pressure head are in contact with each other. The curvature of the two contact surfaces is preferably in the spatial direction, wherein these surfaces are, for example, cylindrical lateral surfaces. The bending is oriented such that the realized axis of rotation extends transversely, in particular perpendicularly, to the pivot axis of the piece of furniture.

In a further advantageous embodiment of the furniture drive, the first longitudinal section of the basic body is a hollow cylinder and the second longitudinal section thereof is a hollow cone. In one embodiment, a threaded portion is integrally formed in the hollow cylindrical portion of the base body, which serves as an axle nut. Alternatively, the spindle nut insert with the threaded portion is inserted into a hollow cylindrical portion of the basic body, which serves as a spindle nut. The basic shape of the basic body changes along its longitudinal extension from a hollow cylinder on one side of the shaft nut insert to a hollow cone on the opposite end of the basic body. The transition between the two basic shapes can be in the middle of the basic body, for example.

In a further embodiment of the furniture drive, the basic body is designed in the form of a log. For this purpose, it is provided that at least one recess is provided starting from a side of the base body for reducing material, which recess is arranged in the base body, wherein the depth of penetration is predetermined. Between the recesses, a plurality of ribs is then formed, as a result of which the log-shaped basic body now has a reduced mass compared to a structure made of solid material. In a further alternative, the base body is designed in the form of a tub or box.

In the latter embodiment, a section is also provided, which is designed as a spindle nut. Alternatively, the spindle nut is screwed onto the base body. In a further alternative, the spindle can be held rotationally fixed and advantageously runs along its longitudinal axis when the motor is running. In this embodiment, the spindle nut is rotatably driven in a positionally fixed manner and the basic body is fixedly connected to the spindle.

Preferably, the pressure head has a pressure plate with an outer side, which is arranged for bearing against the pressure surface of the pivot lever, and an inner side, which faces the basic body, and on which a central bearing is formed, which is radially surrounded by a concave bearing surface. By means of the hollow conical section of the basic body, large axially acting forces can be transmitted from a small surface in the region of the spindle nut to a larger surface of the pressure plate despite the small wall thickness of the basic body.

The central support is responsible for the increased bending strength of the pressure plate. Furthermore, it is preferred that the central bearing section is plugged into the base body, wherein during movement there is at least one movement gap in the spatial direction. The support is thus also a limitation of the lateral movement of the pressure head.

In a preferred embodiment, the end faces of the support part are on the ribs or attachment parts of the base body in order to distribute the forces to be transmitted over as large an area as possible.

As described in detail at the outset, the pressure head can be of plate-like design. The pressure head is relatively thin compared to its width. Typical thicknesses are designed in the range of 3 to 12 mm. Alternatively, the pressure head is designed as a longitudinally extending pressure head, wherein the structural length is greater than 12 mm. The plate-shaped pressure head is preferably formed from a relatively high-strength material, for example from fiber-reinforced or ball-reinforced plastic. Other pressure heads are substantially rigid due to their longitudinal extension and can be formed from standardized plastics without fillers.

In a further advantageous embodiment of the furniture drive, the base body and the pressure head have a latching mechanism for latching connection to one another. The pressure head can be simply mounted on the base body by means of the latching mechanism. For example, the pressure head can have at least one latching hook, and the base body can have at least one latching projection. The latching hook can be guided in the base body, wherein here too a movement gap is provided, so that the desired pivoting or sliding movement of the pressure head can be carried out even with latching.

In a further advantageous embodiment of the furniture drive, a guide rib extending in the longitudinal direction is formed on the base body. The guide ribs prevent twisting of the base body in its guide even in the case of other rotationally symmetrical shapes of the base body. Furthermore, it is preferred that the base body and/or the pressure head have transverse ribs which serve as stops for an actuator for actuating the limit switches. The catch can be, for example, a part of the drawbar, which, when moved, is moved out of the neutral position by the catch abutting against the transverse rib and thus actuates a limit switch, which is arranged on the control circuit board of the electric drive.

The pressure slide according to the invention can be used in a single drive, as in a drive such as a dual drive, which comprises one drive unit and two or more drive units.

Drawings

The invention is explained in detail below with reference to embodiments and with the aid of the figures. These figures show:

fig. 1, 2 show respectively isometric views of a furniture drive from two different viewing directions;

fig. 3 shows an isometric view of the furniture drive of fig. 1 and 2 with the housing open;

fig. 4 shows a side view of the furniture drive of fig. 1 and 2 with the housing open;

fig. 5 shows a further isometric view of the furniture drive of fig. 1 and 2 with the housing open;

fig. 6 to 8 show isometric detailed views of the furniture drive, respectively;

fig. 9 shows an isometric view of the pressure head and the pressure slider of the furniture drive of fig. 1 to 8;

FIG. 10 shows three partial images, each having a top view of a part of a pressure head associated with a pressure slide, the pressure slide and the pressure head having different relative positions to one another, and

fig. 11 shows a top view of a plurality of furniture drives in a single packaging unit.

Detailed Description

In fig. 1 and 2, an exemplary embodiment of a furniture drive according to the present application is shown in an isometric overall view, which is composed of two different viewing directions. As shown in all subsequent figures, like reference numerals designate identical or functionally identical elements, respectively.

The furniture drive has a housing 10 which is substantially square in terms of its basic shape, with a longitudinal extent in a first direction, referred to below as the x-direction, which significantly exceeds the extent in the y-or z-direction perpendicular thereto.

The housing 10 is formed by two half-shells, a first half-shell 11 and a second half-shell 12, wherein a parting line between the two half-

shells

11, 12 extends in the xy-plane. The

half shells

11, 12 are preferably produced from plastic in an injection molding process.

The housing 10 shown in this embodiment is screwed to connect its

half shells

11, 12. For this purpose, screw holes 112 provided in the clamping recesses 111 and 121 are provided in the first housing half shell 11, while screw caps 122 are provided in the second housing half shell 12. Alternatively and/or additionally, the connecting clips which span the parting line between the

half shells

11, 12 and latch with them can be folded into the clamping recesses 111 and 121. In addition to the screw connections provided in the clamping recesses 111, 121, further screw holes 112 can be provided, for example, in the middle-lower region of fig. 1, the first half-shell 11 can be seen.

On the

side

113 or 123 of the housing 10, a slightly

deeper connection recess

114 or 124 is provided, in which terminals and/or display and operating elements for the electric furniture drive are located. Even in the slightly curved side surfaces 113, 123, flat surfaces are provided in the recesses, which simplifies the arrangement of the terminals and the operating elements. In addition, the connection recesses 114, 124 protect the terminals and the display and operating elements during transport or installation.

As can be seen particularly clearly in fig. 2, on the second half-shell 12, the motor housing 125 projects over the side face 123. The motor cover 125 covers the motor housing of the laterally projecting side 123, wherein in the exemplary embodiment shown a single motor cover 125 is provided which spans the housings of two drive motors arranged next to one another.

In addition to the screwing or clamping of the housing 10, other connecting methods are alternatively possible, in particular welding, riveting or gluing the

half shells

11, 12. The welding of the half-

shells

11, 12 made of thermoplastic can be carried out in an ultrasonic process. It is particularly advantageous to have a welding process in which the abutting faces of the

half shells

11, 12 are heated before joining until the plastic material melts at least in the layer near the surface. In a subsequent step, the half shells are joined together with a force fit until the plastic material has become solid again and has joined the plastic material of the respective

other half shell

11, 12.

For heating the plastic surface, radiant heat can be delivered by means of a heating element, for example an infrared radiator. Alternatively and preferably, a so-called hot gas or hot air welding method can be used, wherein the hot gas is precisely positioned towards the connection point via a nozzle distribution system. The advantage of the welding method by preheating the connection points over ultrasonic welding is that the connection between the

half shells

11, 12 in the interior of the housing can also be formed in a targeted manner. In this way, the connection can be made in the housing interior in the region of the force-absorbing or force-transmitting housing section.

Another advantageous way of connection is heat staking. In a method suitable for plastic half-shells, bolt-shaped rivet elements are provided on one of the half-shells, which rivet elements penetrate corresponding through-openings or openings of the other half-shell when the shells are assembled together. Thereafter, the head of the rivet element is heated in a so-called hot gas riveting method and pressed into a rivet head using a cold punch. The advantage in this case is that the geometry of the rivet element can be freely selected. Instead of the bolt, it is also possible to use a larger element in the form of a spring or a tab, which enables a large-area force transmission between the two half-shells.

In the end regions of the housing 10 (viewed in the longitudinal direction of extension), there are provided shaft receptacles 13 in each of which a pivot axis of the piece of furniture oriented in the z direction is supported. In order to insert the pivot shafts into the shaft receptacles 13, in each case a removable slide 14 is provided, which straddles the shaft receptacles 13. The slide 14 is pushed into a correspondingly formed and undercut groove of the

half shells

11, 12. Preferably, the insertion in the z direction is provided, wherein additionally a latching can be provided between the slide 14 and the

half shells

11, 12.

The pivot shaft inserted into the shaft receptacle 13 has a pivot lever, which is then inside the housing 10 and is acted upon by the furniture drive shown, thereby rotating the pivot shaft to adjust the furniture part. A typical application is the combination of the furniture drive with slats for a bed as furniture. These two pivot axes are connected to the head or leg part of the slat, which can be raised or lowered, respectively, by pivoting of the pivot axes. The furniture drive operates the pivot axis and is simultaneously fixed thereto. No additional fastening of the furniture drive to the piece of furniture is required. In operation, the furniture drive is oriented substantially such that the depicted xz-plane extends horizontally and the xy-plane extends vertically.

Fig. 3 and 4 show an overall view of the furniture drive of fig. 1 and 2, respectively, with the first half-shell 11 (see fig. 1, 2) removed to allow the internal structure of the furniture drive to be seen. Fig. 3 is an isometric oblique view in the viewing angle also adopted in fig. 1. Fig. 4 shows the furniture drive in a side view in the xy plane.

The abutting outer edges of the

half shells

11, 12 form a mating surface 127, which can be configured in such a way that the two

half shells

11, 12 are sealed against one another. This is achieved, for example, by forming grooves and springs on the abutment surfaces 127. Additionally, the abutting surfaces of the two half-

shells

11, 12 may be glued to one another or an elastic seal may be interposed. If the connection of the two half-

shells

11, 12 is carried out by means of a welding method, for example the hot gas welding described above, it is possible to provide a profile, for example a chamfer, by means of which the weld seam is prevented from projecting outwards or by means of which the projection is reduced.

In particular, reinforcing ribs are formed in the region of the shaft receptacle 13, which absorb the forces exerted by the pivot shaft on the edges of the shaft receptacle 13 and are distributed in the housing. Directly around the shaft receptacle 13, the reinforcing rib 126 is held flat, since the pivot lever of the pivot shaft moves in this region. If possible, for example, a reinforcing rib 126 is provided adjacent to the end region in order to separate the end region of the housing 10 from the middle section, said reinforcing rib being designed to be so high that it touches a corresponding point of the reinforcing rib provided in the first half-shell 1, not shown here, so that here too an abutment surface 127 is formed between the two reinforcing ribs. In particular, if a joining method is used for the two half-

shells

11, 12, in which method the inner abutment surfaces 127 can also be connected, for example in the hot gas welding process mentioned above, an increased rigidity of the housing 10 can be achieved.

In addition, a centering tab 128 is provided in the region of the screw cap 122, which centering tab projects into a corresponding deepening of the first half-shell 11. When a welding method is used as the joining method, the

half shells

11, 12 can additionally be welded at these points, whereby the size of the

interfaces

11, 12 is further increased.

Two drive units 20 are arranged in the housing 10, each having an electric drive motor 21, which each act via a gear 22 on a brake 23, in this case a torsion spring brake, for the

spindles

24a, 24 b. Optionally, a brake 23, in this case a torsion spring brake, is provided adjacent to the gear 22 for the

spindles

24a, 24 b. Bearings, for example rolling bearings for the

spindles

24a, 24b, are also provided in the housing of the gear 22.

The gear 22 is designed here as a worm gear. The rotation of the drive shaft of the drive motor 21 is transmitted via a spindle arranged on the drive shaft to a preferably obliquely meshing gear of the transmission 22. The toothed wheels are connected in a rotationally fixed manner to the

respective spindle

24a, 24b, so that the spindles can be rotated at a reduced rotational speed by the drive motor 21. The pressure slide 25, into which the

spindles

24a, 24b enter, is placed on the free end of the

spindles

24a, 24b opposite the gear 22, respectively. The pressure sliders 25 are each mounted in the housing 10 in a slidable manner in the x direction, wherein a twisting of the pressure sliders 25 is prevented by this mounting.

In the interior of the pressure slide 25, a spindle nut is arranged in a rotationally fixed manner, which interacts with the

spindles

24a, 24b and converts the rotation of the

spindles

24a, 24b into a sliding movement of the respective pressure slide 25. At the end of the

spindles

24a, 24b opposite the associated transmission 22, a pressure head 26 is placed on the pressure slide 25, against which pressure head the pivot lever used rests and a force is transmitted to the pivot lever in order to pivot the pivot shaft.

The element of the linear movement of the drive unit 20 is the output part of the drive unit 20. The linearly moving element is here a spindle nut or an element which is connected mechanically or by a material fit to the spindle nut is in the example shown also a pressure slide 25 with a pressure head 26. When the

spindles

24a, 24b rotate, the spindle nuts run along the threaded

spindles

24a, 24b and in operation connect and couple directly or indirectly to the pressure head 26.

In an alternative embodiment, the output part of the rotational speed reduction gearbox, which may be formed, for example, by a worm of a worm drive, has a stationary and rotatably driven spindle nut. The spindle is guided in a stationary manner in this case. The spindle is the output part of the linear movement of the drive unit 20 when the spindle nut is rotated. The output component is also coupled in operation directly or indirectly to a pressure head 26 mounted in a floating manner.

In both drive units 20, the same movement path is provided for the presser slide 25. In fig. 3 and 4, respectively, a completely or approximately completely retracted position of the pressure slide 25 is shown, wherein it is always approximately completely possible for the pressure slide to be retracted in each case toward the middle (viewed in the longitudinal direction x) of the housing 10.

Although the presser slide 25 has substantially the same path of movement in both drive units 20, the drive units 20 differ in the length of their

main shafts

24a or 24 b. The length of the spindle 24a is selected here such that the required path of movement of the presser slide 25 is achieved and at the same time the drive motor 21 and the gear 22 are positioned as close as possible to the respective shaft receptacle 13.

However, the second drive unit 20 has a substantially longer spindle 24b, wherein the length of the spindle 24b is selected given the distance of the shaft receptacles 13 such that the drive motors 21 or the gear 22 of the two drive units 20 are arranged in the housing 10 substantially directly adjacent to one another. Here, for example, only one reinforcing rib 126 is provided between the two drive units.

The different lengths of the

spindles

24a, 24b result in a division of the available positions in the housing 10, which is advantageously different from the known structuring of the interior of the housing of the dual drive device. In addition to the end region provided with the shaft receptacle 13, the interior of the housing 10 is divided into a first installation space 15a above the main shaft 24a and a larger second installation space 15b above the main shaft 24 b.

In the dual drive arrangements known from the prior art, two drive units are constructed with spindles as short as possible, the length of which is similar to the length of the spindle 24 a. In addition to the end regions, the available interior of the housing is thus divided into three structural spaces, one above the spindle and the third between the two drive motors. Accordingly, the installation space available in the housing according to the prior art is approximately divided into three equally large sections, where it is divided into only two sections, one of which, installation space 15a, has the same size as the installation space of the prior art, and the other (installation space 15b is approximately twice as large, even if all available installation spaces are not increased with the same length of the furniture drive, the installation space is still divided to a lesser extent, which provides greater design freedom when electrical and electronic components are to be arranged in the installation space.

It should be noted that in the illustrated embodiment, an eccentric arrangement of the drive motor 21 is achieved by different lengths of the

main shaft

34a or 34 b. An equivalent embodiment is to provide that the spindles of the two drive units are of equal length, but the output elements, for example the pressure slide, have different lengths. A combination of the two embodiments is also contemplated.

In the exemplary embodiment shown, the control circuit board 30 (article "a", "b") is arranged in the larger of the two resulting installation spaces 15 b. The control circuit board 30 has two regions, which are schematically separated from one another by a dashed line in fig. 3. In the part of the control circuit board 30 shown on the right in fig. 3, a power network component 31 is provided, while in the area shown on the left in the figure there is a control device 32. The grid part 31 has a grid terminal 311 into which a grid cable can be inserted from the outside. The network component 31 is preferably a switched network component with a high-frequency transmitter, the electronic components of which are not depicted on the control circuit board 30 for reasons of overview, which has a smaller space requirement, a smaller weight and is more efficient, in particular, in idle operation, than conventional low-frequency transformers. At the output of the network component 31, a low voltage, preferably in the range of 20 to 30 volts (volts), for example a nominal 24V dc voltage, is available, which low voltage is supplied to the control device 32 and the drive motor 21.

By forming a large installation space 15b, a single control circuit board 30 can be used, and there are places on the network element 31 and the control device 32. The narrow, elongated design of the control circuit board 30 in this case allows a reliable isolation of the mains voltage, which is processed in the region of the mains component 31 and which is supplied to the control device 32, from low voltages.

The control device 32 comprises means for controlling the drive motor 21. Such components may be electrically operated switching mechanisms, such as relays, or semiconductor switches, such as MOSFET (metal oxide semiconductor field effect transistor) transistors or IGBT (insulated gate bipolar transistor) transistors. The switching mechanism either has a plurality of contact groups or is wired in the form of an H-bridge so that the direction of rotation of the drive motor 21 can be switched.

The switching mechanism is controlled in accordance with input information of the control circuit board 30, which is transmitted, for example, by an external remote control device (also referred to as a manual control device). For this purpose, a control terminal 321 accessible from the outside is formed in the area of the control device 32. Furthermore, an operating and/or display element 322 is provided, which may have a touch function, for example, in order to be able to reset the function of the control device 32. Furthermore, a lighting device 323, for example in the form of a light-emitting diode, can be arranged on the control circuit board 30, which illuminates the environment of the electric furniture drive through a corresponding opening or window in the

half shells

11, 12. In this way, for example, floor lighting can be realized, which is activated for a certain time after the corresponding key on the remote control is operated, so that it is easy to get up at night without having to switch on the room lighting.

Furthermore, a limit switch 33 is provided on the control circuit board 30, which limit switch is operated by the push slider 25 via a pull rod 34. The limit switch 33 prevents the movement of the pressure slide 25 outside the permissible range, for example in order to mechanically abut the pressure slide 25 against the housing 10 or the gear 22 or the brake 23 or to prevent contact between the ends of the

spindles

24a, 24b and the pressure head 26 in the interior of the pressure slide 25. The arrangement of the fiber switch 33 directly on the control circuit board 30 reduces the wiring complexity which would otherwise occur if the limit switch were positioned directly in the region of the pressure slide 25. The transmission of the position or movement of the presser slide 25 to the limit switch 33 via the drawbar 34 is explained in detail below in connection with fig. 5 to 8.

Fig. 5 shows an isometric oblique view of the electromotive furniture drive from a laterally oblique position. Fig. 6 shows a partial side view of the furniture drive, slightly inclined from above, in the region of the control circuit board 30, in the same isometric view. Fig. 7 and 8 are detailed views of the furniture drive in the region of the control device 32 of the control circuit board 30, wherein the upper side of the control circuit board 30 in fig. 7 or the lower side of the control circuit board 30 in fig. 8 can be seen.

In fig. 5 to 8, the first half-shell 11 is again removed as in fig. 3 to 4 (see fig. 1 and 2).

Each of the drive units 20 is provided with a

traction rod

34a or 34 b. The

traction rods

34a, 34b are produced in one piece from plastic in the embodiment shown by injection molding. In order to achieve sufficient pressure stability despite the length of the

traction rods

34a, 34b and to enable a torsion-proof guidance within the housing 10, the

traction rods

34a, 34b are provided with a guide web 341 extending in the longitudinal direction. In the

half shells

11, 12, stiffening ribs 126 are formed in the region of the

traction rods

34a, 34b, so that the stiffening ribs form a guide for the

traction rods

34a, 34b, in which the

traction rods

34a, 34b are guided displaceably in their longitudinal direction. The

traction rods

34a, 34b extend substantially parallel to and within the

spindles

24a, 24 b. At each of its ends, a downwardly directed driver 342 is formed, which, when the pressure slide 25 is just before one or the other end of its permitted path of movement, projects into the path of movement of the pressure slide 25 and is driven by transverse ribs formed on the pressure slide 25.

A likewise downwardly directed spring cam 343 is formed on the opposite end of the

respective traction rod

34a, 34 b. In the region of the spring cam 243, a

return spring

35a, 35b, which is formed by a w-shaped bent spring plate, is provided on the housing 10 for each

traction lever

34a, 34b, said plate being fastened with its central region to the housing 10 and resting with lateral spring arms on lateral edges of the spring cam 343. In addition, stops for the spring arms are provided on the housing 10, which stops are positioned between the spring arms and allow each of the spring arms to be moved laterally outward, but prevent the spring arms from being able to move deeper inward than in the neutral position shown.

In the neutral position of the

exemplary traction rods

34a, 34b, which is clearly visible in fig. 6 and 8, the spring cam 343 (depending on the design of the stop for the spring arms on the housing 10) either exerts no spring force or exerts a spring force from both sides equally via the spring arms of the return springs 35a, 35b, so that the sum of the return springs 35a, 35b does not exert a force acting in one direction or the other of the

traction rods

34a, 34 b.

When the

draw rods

34a, 34b are moved in one direction or in the other, a restoring force acting toward the neutral position is then exerted on the spring cam 343 by the restoring

springs

35a, 35b, respectively. Accordingly, when no catch 342 is deflected in one direction or in the other from the transverse rib 254 of the presser slider 25, the

traction rods

34a, 34b assume the neutral position shown by the return springs 35a, 35 b.

On the upper side of the

draw rods

34a, 34b, in each case a switching cam 344 is formed in the end region where the spring cam 343 is present. The rod-shaped sections of the

draw rods

34a, 34b and the spring cam 343 are arranged here below the control circuit board 30, while the switch cam 344 is located on the upper side of the control circuit board 30. The

draw rods

34a, 34b have for this purpose upwardly directed longitudinal webs from which the switching cams 344 project laterally. In the control circuit board 30, a slot-shaped recess 324 is introduced for the threading of the longitudinal webs. The groove-shaped recess 324 opens out to the side of the control circuit board 30 shown on the left in fig. 7 and 8. In this sequence, the

pull rods

34b, 34a can be inserted into the groove-shaped recesses 324 during the installation of the furniture drive. In addition to the guide formed in the housing 10 for the

traction rods

34a, 34b, the groove-shaped recess 324 also forms a guide for the

traction rods

34a, 34b in conjunction with the longitudinal web carrying the switching cam 344.

On the upper side of the control circuit board 30, a

limit switch

33a or 33b is provided in the region of the switch cam 344, which limit switch is operated by the switch cam 344. For each drive unit 20, two

limit switches

33a or 33b are provided, wherein the

limit switches

33a, 33b and the switch cam 344 are configured such that neither

limit switch

33a, 33b is operated in the respective neutral position of the

traction lever

34a, 34 b. Each of the two limit switches 33a or two limit switches 33b is operated if the

respective tow bar

34a, 34b is deflected in one of the directions.

On the control circuit board 30, the

limit switches

33a, 33b are wired with a switching mechanism for controlling the drive motors 21 in such a way that the respective drive motor 21 is prevented from continuing to run when one of the limits is reached, while the drive motor 21 can be reversed. For this purpose, for example, each of the

limit switches

33a, 33b can be assigned a diode, which is wired to the switching contact of the

limit switches

33a, 33 b.

The small installation space 34a not occupied by the control circuit board 30 can be used for other electrical or electronic components. Alternatively, for example, a battery compartment is provided in the installation space 34a, into which a battery accessible from the outside can be inserted, which battery can supply the electric clamp drive with current at least temporarily in the event of a current failure, in order to be able to carry out emergency driving into the desired basic position. As an alternative to the battery compartment accessible from the outside, a rechargeable battery can also be provided in the installation space 34a for emergency driving, which then does not have to be accessible from the outside and which is held in the fully charged state by the charging control circuit via the control circuit board 30.

Furthermore, a receiving module, for example for wireless remote control, or other optional additional modules, can be arranged in the installation space 34a, with which the functionality of the control device 32 is supplemented. In addition or alternatively, a plug connector can also be provided on the control circuit board 30, into which the supplementary circuit board can be inserted perpendicularly or parallel to the control circuit board 30.

Furthermore, it can also be seen in fig. 5 that the shaft of the drive motor 21 does not extend parallel to the pivot axis, but is inclined in the yz plane by approximately 20 to 25 degrees relative to the pivot axis. The inclination is selected such that the rear end of the motor housing of the drive motor 21 does not project upwards beyond the other structural height of the furniture drive. Thus, a reduction of the width of the furniture drive in the z direction is achieved by the tilting. In this way, the motor housing 125 protrudes less far out of the side face 123 than if the motor shaft were oriented in the z-direction.

Fig. 9 shows a detail of the pressure slide 25 with the pressure head 26 in an isometric view. The pressure head 26 is shown in this figure independently of the pressure slide 25.

The pressure slide 25 is preferably a one-piece or multi-piece plastic part made of a plastic that can withstand high loads and is resistant to breaking, for example POM (polyoxymethylene). The pressure slide 25 is composed of two elements, namely a hollow base body 251 and a spindle nut insert 253. Guide webs 252 which project outward in the longitudinal direction are formed on the base body 251 and additionally also serve to reinforce the base body 251.

It should be noted that the drive unit 20 is subjected to a load in the normal operating state of the furniture drive. When the drive motor 21 is switched on, the load connected to the drive unit 20 can be moved, but even when the drive motor 21 is switched off, the load connected to the drive unit 20 is maintained. In this normal operating state, a force is accordingly also applied to the pressure slide 25. When the pressure slide 25 is formed in multiple parts, the individual parts do not necessarily have to be connected to one another in a form-fitting manner. They can also abut, wherein a force consisting of a load cooperates with the axial force to press the parts against each other. In this case, a lateral guide is preferably used for each of the components in the housing 10. The surfaces for the different parts of the pressure slide 25 which bear against one another can be flat or, in terms of these, concave or convex (for example spherical), so that an angular compensation can be achieved between the different parts of the pressure slide 25.

A spindle nut insert 253 is used in the end region of the base body 251. A threaded section is formed in the center of the spindle nut insert 253, which serves as a spindle nut for the

spindles

34a, 34 b. The threaded section projects into the interior of the base body 251. On the outer side visible in fig. 9, the plate of the spindle nut insert 253 protrudes through the opening of the base body 251 and rests against the end face thereof. In this way, a large force is transmitted from the shaft nut insert 253 to the base body 251. Furthermore, the plate of the spindle nut insert 253 is a transverse rib 254 which projects outwards from the base body 251 and serves as a stop for the driver 342 of the

traction rod

34a, 34 b. For this purpose, another lateral rib 254 is formed on opposite sides of the base body 251.

The basic shape of the base body 251 changes along its longitudinal extension from a hollow cylinder on one side of the shaft nut insert 253 to a hollow cone on the opposite end of the base body 251. The transition between the two basic shapes takes place approximately in the middle of the base body 251. The diameter of the base body 251 widens toward the end opposite the spindle nut insert 253.

The pressure head 26, here in the form of a plate, is inserted into the widened opening of the base body 251. The pressure head has a pressure plate 261 with an outwardly directed pressure surface 262, on which a pivot lever of a pivot shaft of the piece of furniture rests. On the opposite side of the pressure plate 261, a support 264 is formed, which projects into an opening of the base body 251 of the pressure slide 25. The pressure slide 261 projects beyond the bearing 264 so that an abutment surface 263 is formed, with which the pressure head 26 abuts against the end-side abutment surface 255 of the pressure slide 25. The pressure head 26 and the pressure slider 25 are latched to one another, wherein in this example latching hooks 265 are formed on the pressure head 26, which latching hooks engage in the latching guides 256 and each snap into a latching projection 257 of the rear section.

The geometry and dimensions of the bearing 264 are selected such that the pressure head 26 can be moved in the y-direction and/or the z-direction relative to the pressure slide 25. In the embodiment shown, there is a gap for movement in the z direction. During the displacement, the pressure head 26 does not perform a linear movement, but rather a pivoting movement. This is achieved on the one hand by a corresponding design of the contact surface 255 of the base body 251 and on the other hand by a corresponding design of the contact surface 263 of the pressure head 26. The contact surface 255 of the pressure slider 25 is formed concave in the z direction, while the contact surface 263 of the pressure head 26 is formed convex in the z direction. The pivoting movement enables angular compensation if the contact surface of the pivot lever is not oriented exactly in the z direction.

In fig. 10, three partial views of a possible angular movement are shown by way of a top view of the end region of the pressure slide 25 on which the pressure head 26 has been placed. In the middle sub-diagram (b) of fig. 10, the pressure head 26 is in a central position relative to the pressure slide 25. In order to be able to move the pressure head 26, the latching hook guide 256 is formed slightly wider than the width of the latching hook 265 itself. In sub-drawing (b), the latching hook 265 is located in the latching hook guide 256. The left-hand illustration (a) shows the pressure plate 26 deflected and pivoted to the left, viewed from the pressure slide 25. Sub-figure (c) shows the pressure plate 26 pivoted to the right as seen from the pressure slide 25. The play provided by the detent hook 265 in the detent hook guide 256 is matched to the play of the bearing in the opening of the base body 251, so that a stop for the pressure head 26 is preferably formed by the bearing 254 abutting against a wall of the base body 251, since this stop can absorb a greater force than the detent hook 265.

As can be seen particularly clearly in fig. 5, the pressure surface 262 of the pressure head 26 can also be formed non-planar. In this case, the pressure surface 262 is slightly inclined in the upper region in order to prevent a section of the pressure surface 262 from resting on the pivot axis.

Furthermore, the extension of the spindle 24b relative to the spindle 24a and the corresponding change in the arrangement of the drive motor 21 and the gear 22 relative to one another result in advantages compared to the prior art when packaging a plurality of the electric furniture drives described. By lengthening the spindle 24b relative to the spindle 24a, the drive motors 21 are positioned close to one another, so that a single motor housing 125 can be formed on the second half-shell 12, which comprises both housings of the drive motors 21. Further, the motor cover 125 is not provided centrally on the longitudinal side of the housing 10, but is provided in the outer center. The arrangement of the outer center section allows two furniture drives to be positioned within the packaging unit with the second half shells 12 facing each other, wherein only a movement of the furniture drives in the longitudinal direction relative to each other or, depending on the geometry, even a movement of the furniture drives in the longitudinal direction relative to each other is not necessary.

This is illustrated in fig. 11 for ten furniture drives arranged in pairs in the position of the packaging unit 40. By the arrangement of the motor housings 125 in the outer middle on the housing 10 of the furniture drive, the furniture drive is arranged in pairs crosswise to one another without it having to be moved significantly in the longitudinal direction relative to one another. In this way, the storage space available in the packaging unit 40 is optimally utilized. In the example shown, the packaging unit 40 is based on a european pallet 41, onto which a cardboard box 42 rests. A plurality of the shown positions of the furniture drive can be packed on top of each other in a cardboard box 42. In order to be able to stack two or more packaging units 40 on top of one another, if appropriate, vertical support rollers 43 are arranged distributed in the interior of the cardboard box 42, which can be made of cardboard material, for example the cardboard box 42.

List of reference numerals

10 casing

11 first half shell

111 grip recess

112 screw hole

113 side surface

114 connecting recess

12 second half-shell

121 grip recess

122 screw cover

Side 123

124 connection recess

125 motor cover

126 reinforcing rib

127 abutting surface

128 centering tab

13 axle receiving part for pivot axle of clamp

14 slide block

15a, 15b structural space

20 drive unit

21 drive motor

22 transmission device

23 brake

24a, 24b spindle

25 pressing slide block

251 base body

252 guide web

253 spindle nut connector

254 transverse rib (stop for driver)

255 convex contact surface

256 latch hook guide

257 snap lock tabs

26 pressure head

262 pressure plate

262 pressure surface

263 concave contact surface

264 support part

265 locking hook

30 control circuit board

31 grid element

311 grid terminal

32 control device

321 control terminal

322 operating or display element

323 lighting element

324 recess

33a, 33b limit switch

34a, 34b tow bar

341 guide web

342 entrainment member

343 spring cam

344 switch cam

35a, 35b return spring

40 packaging unit

41 European tray

42 cardboard box

43 support the rollers.

Claims

1. An electromotive furniture drive for adjusting at least one furniture part of a piece of furniture, comprising: at least one drive unit (20) comprising a drive motor (21), a transmission (22) and a spindle drive which acts on a pressure slide (25) which is movable along a movement path, characterized in that a basic body (251) of the pressure slide (25) is provided with a pressure head (26) which is mounted in a floating manner; wherein the pressure head (26) is mounted on a base body (251) of the pressure slide (25) such that the pressure head (26) can perform a pivoting movement on a circular track.

2. Electromotive furniture drive according to claim 1,

wherein the base body (251) has a convex contact surface (255) and the pressure head (26) has a concave contact surface (263), so that the base body (251) and the pressure head (26) are in contact with one another.

3. Electromotive furniture drive according to claim 1,

wherein the longitudinally extending first section of the base body (251) is hollow cylindrical and the longitudinally extending second section of the base body (251) is hollow conical.

4. Electromotive furniture drive according to claim 3,

integrally formed in the hollow cylindrical portion of the base body (251) is a threaded portion which serves as a spindle nut.

5. Electromotive furniture drive according to claim 3,

wherein a spindle nut insert (253) having a threaded section is inserted into the hollow cylindrical section of the base body (251), said threaded section serving as a spindle nut.

6. Electromotive furniture drive according to claim 2,

wherein the pressure head (26) has a pressure plate (261), the pressure plate (261) having an outer side which is configured for bearing against a pressure surface (262) of a pivot lever and an inner side which faces the basic body (251), and a central bearing (264) which is radially surrounded by a concave-shaped bearing surface (263) being formed on the inner side.

7. Electromotive furniture drive according to claim 6,

wherein the central bearing (264) is plugged into the base body (251), wherein there is at least one play in the spatial direction during the movement.

8. Electromotive furniture drive according to claim 1,

wherein the base body (251) and the pressure head (26) have a latching mechanism for latching connection to one another.

9. Electromotive furniture drive according to claim 8,

wherein the pressure head (26) has at least one latching hook (265) and the base body (251) has at least one latching projection (257).

10. Electromotive furniture drive according to claim 1,

wherein a guide rib (251) extending in the longitudinal direction is formed on the base body (251).

11. Electromotive furniture drive according to claim 1,

wherein the base body (251) and/or the pressure head (26) have transverse ribs (254) which serve as stops for a driver (242) for actuating limit switches (33a, 33 b).