EP3267844B1 - Electromotive drive for furniture - Google Patents

Description

The invention relates to an electromotive furniture drive for adjusting at least one furniture part of a piece of furniture with at least one drive unit, which has a drive motor, a gear and a spindle drive which acts on a sliding along a displacement pressure slide, wherein a main body of the pressure slide is a floating printhead assigned.

Such electromotive furniture drives are used to be able to adjust furniture parts such as a headboard or a footboard of a slatted frame or a backrest or a footrest of an armchair by electric motor. The furniture drives may e.g. be designed as individual drives with a drive unit or as double drives with two drive units. Double drives can be easily mounted on the furniture, for example, the said slatted bed, by a respective pivot axis of the furniture is inserted into each one formed on the furniture drive axle. For this purpose, the axle mounts are usually provided with cover slides, which can be removed in order to insert the pivot axis with a pivot lever in the axle can. After replacing the cover slide, the entire double drive is fixed to the axles. The drive units act independently on their spindle drive and the pressure slide on the respective pivot lever for adjusting the furniture parts.

Such a furniture drive with a pressure slide as the output member, which is linearly displaceable via a spindle drive, for example, from the document DE 203 02 139 U1 known. In this furniture drive, the pressure slide on a substantially cylindrical pressure piece, in which a spindle nut is inserted on one side and on the opposite side of a pressure plate is placed. The spindle of the spindle drive engages in the spindle nut and penetrates into the inner, hollow portion of the pressure piece to a maximum of the pressure plate. On an outer side of the pressure plate is a pivot lever of a pivot axis of a furniture part to its adjustment. The pressure piece is made from a profiled rail section with a quadrangular cross-section.

The publication DE 20 2008 016049 U1 describes a trained as a double drive furniture drive, in which a longitudinally movable and rotatable spindle is inserted into a stationary and rotatable spindle nut. Upon rotation of the spindle nut, the spindle travels depending on the direction of rotation in the one way or the other. Each spindle end acts via a pressure slide on a pivot lever, wherein between the pressure slide and the pivot lever connected to one of the two components printhead is inserted.

A disadvantage of the known pressure slides is that when not exactly center on the pressure plate or the print head fitting pivot lever or a pivot lever whose bearing surface is not aligned parallel to the surface of the pressure plate, a strong tilting moment acts on the pressure slide, which loads the pressure slide and Transverse forces on the linear guide of the pressure slide exerts. The lateral forces lead to a higher friction of the guide and thus to a greater wear. If the bearing surface of the pivot lever is not aligned parallel to the surface of the pressure plate, the contact area between the pivot lever and the pressure plate is smaller, which increases the pressure acting on the contact surface.

It is therefore an object of the present invention to provide an electromotive furniture drive of the type mentioned, in which acting on the pressure slide tilting moments are reduced and in which even with a not exactly parallel to the surface of the pressure plate aligned bearing surface of the pivot lever as large a contact surface between the two parts is formed.

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

An electromotive furniture drive of the type mentioned above is characterized in that the print head is mounted on the main body of the pressure slide such that it is movable in a pivoting movement on a circular path. The floating-mounted printhead compensates for a pivot lever that is not aligned exactly parallel, thus increasing the contact surface again. It is possible both a sliding and a pivoting movement, which is particularly well suited for angle compensation. A center of the circular path can be, for example, on the axis of the spindle.

The print head can be arranged in front of or on the main body of the pressure slide. It may be connected to the print head, for example, positively connected, so that it is a unit with the main body forms, with a movement to compensate for a not exactly parallel aligned pivot lever is allowed. Alternatively, the printhead may also be coupled in a non-positively connected manner to the main body of the pressure slide by being positioned between the main body and the pivot lever.

A combined sliding and pivoting movement can be realized structurally simple in that the base body has a convex bearing surface and the print head has a concave bearing surface, with which the base body and the print head lie on one another. The curvature of the two bearing surfaces is preferably in a spatial direction, wherein the surfaces are, for example, cylinder jacket surfaces. The curvatures are aligned so that the axis of rotation achieves transverse, in particular perpendicular, to the pivot axis of the furniture.

In a further advantageous embodiment of the furniture drive, the main body is hollow cylindrical in a first portion of its longitudinal extent and in the form of a hollow cone in a second portion of its longitudinal extension. In one embodiment, a threaded portion is formed integrally in the hollow cylindrical portion of the base body, which serves as a spindle nut. Alternatively, a Spindelmuttereinsatz is inserted with a threaded portion serving as a spindle nut in the hollow cylindrical portion of the body. The basic shape of the basic body varies along its longitudinal extent from a hollow cylinder on the side of the spindle nut insert to a hollow cone on the opposite end of the basic body. The transition between the two basic forms may be, for example, in the middle of the main body.

In a further embodiment of the furniture drive, the base body is formed block-like. For this purpose, it is provided to arrange at least from a side surface of the main body outgoing recesses for material reduction, which are set in the body with a predetermined depth into it. A plurality of ribs is then formed between the recesses, as a result of which the block-like basic body now receives a mass-reduced structure compared with a structure made of a solid material. In another alternative, the body is trough-shaped or box-shaped.

Also in these latter embodiments, a section is provided, which is designed as a spindle nut. Alternatively, a spindle nut is on attached the main body. In a further alternative, the spindle can be held against rotation and moves when the motor is running along its longitudinal axis. In this embodiment, the spindle nut is rotatably driven stationary and the body is firmly connected to the spindle.

Preferably, the print head has a pressure plate with an outer side, which is designed as a pressure surface for conditioning the pivot lever and an inner side facing the main body, on which a central nozzle is formed, which is radially surrounded by the concave support surface. Due to the hollow cone-shaped portion of the body, this large axially acting forces can be transferred from a small area in the spindle nut to the larger area of the pressure plate despite the small wall thickness of the base body.

The central nozzle ensures an increased flexural rigidity of the printing plate. More preferably, the central neck is inserted into the body, with a range of motion is given in motion in at least one spatial direction. The neck thus also represents a limit to the lateral movement of the print head.

In a preferred embodiment, the end face of the neck abuts ribs or lugs of the body to distribute the forces to be transmitted as large as possible.

As described in more detail above, the print head can be designed plate-shaped. He is relatively thin compared with its width. Typical thicknesses are in the range of 3 to 12 millimeters. Alternatively, the print head is designed as an elongated print head, the overall length measuring more than 12 millimeters. Plate-shaped printheads are preferably formed of a higher strength material, such as a fiber or ball reinforced plastic. Other printheads have a basic robustness because of their longitudinal extension and can be formed from a standardized plastic without filler.

In a further advantageous embodiment of the furniture drive, the base body and the print head latching means for latching connection with each other. By the locking means can be done on the base body a simple mounting of the print head. For example, the print head can have at least one latching hook and the base body has at least one latching projection. The latching hook can be performed in the base body, with a range of motion is also given here, so that the desired pivoting or sliding movement of the print head can also be done with locking.

In a further advantageous refinement of the furniture drive, guide ribs extending in the longitudinal direction are formed on the base body. The guide ribs prevent even in an otherwise rotationally symmetrical shape of the body rotation of the body in his leadership. More preferably, the base body and / or the print head on transverse ribs, which serve as stops for a driver for the operation of limit switches. The driver may for example be part of a tow bar, which is moved when moving through the stop of the driver on the transverse ribs from a neutral position and then actuates limit switches, which are arranged on a control board of the electric motor drive.

The pressure slide according to the invention can be used in single drives, which have a drive unit as well as in drives, e.g. Double drives comprising two or more drive units.

Figur 1, 2

jeweils eine isometrische Ansicht eines Möbelantriebs aus zwei unterschiedlichen Blickrichtungen;

Figur 3

eine isometrische Ansicht des Möbelantriebs der Figuren 1 und 2 mit geöffnetem Gehäuse;

Figur 4

eine Seitenansicht des Möbelantriebs der Figuren 1 und 2 mit geöffnetem Gehäuse;

Figur 5

eine weitere isometrische Ansicht des Möbelantriebs der Figuren 1 und 2 mit geöffnetem Gehäuse;

Figuren 6-8

jeweils eine isometrische Detailansicht des Möbelantriebs;

Figur 9

eine isometrische Darstellung eines Druckschiebers und eines Druckkopfes des Möbelantriebs der Figuren 1 bis 8;

Figur 10

drei Teilbilder mit jeweils einer Draufsicht auf einen Teil des Druckschiebers mit Druckkopf in verschiedenen Relativpositionen zueinander; und

Figur 11

eine Draufsicht auf Anzahl von Möbelantrieben in einer Verpackungseinheit.

The invention will be explained in more detail using an exemplary embodiment with reference to figures. The figures show:

FIG. 1, 2

in each case an isometric view of a furniture drive from two different viewing directions;

FIG. 3

an isometric view of the furniture drive FIGS. 1 and 2 with the housing open;

FIG. 4

a side view of the furniture drive the FIGS. 1 and 2 with the housing open;

FIG. 5

Another isometric view of the furniture drive FIGS. 1 and 2 with the housing open;

Figures 6-8

in each case an isometric detailed view of the furniture drive;

FIG. 9

an isometric view of a pressure slide and a print head of the furniture drive the FIGS. 1 to 8 ;

FIG. 10

three partial images, each with a plan view of a portion of the pressure slide with printhead in different relative positions to each other; and

FIG. 11

a plan view of the number of furniture drives in a packaging unit.

In the FIGS. 1 and 2 an embodiment of a furniture drive according to the application is shown in each case in an overall isometric view from two different directions of view. In these as in all subsequent figures, like reference numerals each show the same or equivalent elements.

The furniture drive has a housing 10 which, with respect to its basic shape, is substantially parallelepiped-shaped with a longitudinal extent in a first direction, hereinafter referred to as the x-direction, which clearly exceeds the extent in the y- or z-directions perpendicular thereto.

The housing 10 is constructed from two housing half shells, a first housing half shell 11 and a second housing half shell 12, wherein a dividing line between the two housing half shells 11, 12 extends in the xy plane. Preferably, the housing half shell 11, 12 are made of plastic in an injection molding process.

The housing 10 shown in this embodiment is bolted to connect its housing half shells 11,12. For this purpose, screw holes 112 arranged in clamping recesses 111 and 121, respectively, are provided in the first housing half shell 11 or screw domes 122 in the second housing half shell 12. Alternatively and / or additionally, the dividing line between the housing halves 11, 12 cross-over and latching with these connecting terminals can be clipped into the clamping grooves 111 and 121, respectively. In addition to the screw connections arranged in the clamping recesses 111, 121, further screw holes 112 may be provided, such as in FIG FIG. 1 can be seen in the lower middle region of the first housing half shell 11.

On side surfaces 113 and 123 of the housing 10 slightly recessed connection troughs 114 and 124 are arranged, in which connections and / or display and control elements are positioned for the electromotive furniture drive. Even with slightly curved side surfaces 113, 123, a flat surface is provided within the wells, which simplifies the arrangement of terminals and controls. The connection troughs 114, 124 also protect the connections and display and operating elements during transport or assembly.

As in particular in FIG. 2 As can be clearly seen, a motor dome 125 protrudes beyond the side surface 123 on the second housing half shell 12. The motor dome 125 covers laterally over the side surface 123 protruding motor housing, wherein in the illustrated embodiment, a single motor dome 125 is provided which engages over the housing of two juxtaposed drive motors.

In addition to a screwing or clamping of the housing 10, other connection methods are alternatively possible, in particular a welding, riveting or gluing the housing half shells 11, 12. A welding housing half shells 11, 12, which are made of thermoplastic material, can be carried out in an ultrasonic process. Particularly advantageous is a welding process, are heated in the abutting surfaces of the housing halves 11, 12 prior to assembly until the plastic material melts at least in a near-surface layer. In a next step, the housing half shells are put together precisely under the action of force until the plastic has become firm again and has bonded to the plastic of the respective other housing half shell 11, 12.

For heating the plastic surfaces radiant heat may be generated by heating elements, e.g. Infrared emitters are supplied. Alternatively and preferably, a so-called hot gas or hot air welding method can be used, in which a hot gas is directed via a nozzle distribution system exactly localized on the connection points. An advantage of the welding method by preheating the connection points with respect to ultrasonic welding is that targeted connections between the housing half shells 11, 12 can also be formed in the interior of the housing. Thus, a connection in the region of force-receiving or force-transmitting housing sections take place inside the housing.

Another advantageous type of connection is hot riveting. In this method, which is suitable for plastic housing half-shells, bolt-shaped rivet elements are arranged on one of the housing half shells, which penetrate corresponding openings or openings of the other housing half shells when assembling the housing. Thereafter, in the so-called Heißgasnietverfahren the head of the rivet element is heated and pressed with a cold punch to a rivet head. An advantage of this is that the geometry of the rivet element can be chosen freely. In addition to the aforementioned bolts It is also possible to use larger elements in the form of tongues or lugs, which enable a large-area power transmission between the two housing half-shells.

In the end regions (viewed in the direction of longitudinal extent) of the housing 10, axle receptacles 13 are arranged, in each of which a pivot axis of a piece of furniture oriented in the z-direction is mounted. To insert the pivot axis in the axle 13 each have a removable slider 14 is provided, which engages over the axle 13. The slider 14 is pushed into correspondingly shaped and undercut grooves of the housing halves 11, 12. Preferably, an insertion in the z-direction is provided, wherein in addition a locking between the sliders 14 and the housing half-shells 11, 12 may be provided.

The pivot shafts used in the Achsaufnahmen 13 have a then within the housing 10 lying pivot lever, which is acted upon by the furniture drive shown with force, whereby the pivot shafts are rotated to adjust furniture parts. A typical application is the furniture drive shown in connection with a slatted bed of a bed as furniture. The two pivot shafts are connected to a head or a foot part of the slatted frame, which can be raised or lowered by pivoting the pivot shafts accordingly. The furniture drive actuates the pivot shafts and is fixed to them at the same time. A beyond Bestbestigung the furniture drive on the furniture is not required. In operation, the furniture drive is essentially oriented so that the drawn xz plane is horizontal and the xy plane is vertical.

In the Figures 3 and 4 is an overall view of the furniture drive the FIGS. 1 and 2 illustrated, wherein the first housing half shell 11 (see. FIGS. 1 . 2 ) is removed to provide insight into the internal structure of the furniture drive. The FIG. 3 is an isometric oblique view from the point of view, which is also in FIG. 1 is taken. The FIG. 4 shows the furniture drive in a side view on the xy plane.

The superimposed outer edges of the housing halves 11, 12 form abutment surfaces 127, which can be profiled so that a seal of the two housing halves 11, 12 to each other. This is possible, for example, by forming tongue and groove on the abutment surfaces 127. In addition, the abutment surfaces 127 of the two housing halves 11, 12 with each other be glued or it may be an elastic seal between. If a connection of the two housing half shells 11, 12 by a welding process, for example, the aforementioned hot gas welding, a profiling, for example, a chamfer may be provided by which prevents a weld protrudes outward, or by which a supernatant is reduced ,

In particular in the area of the axle receptacles 13, stiffening ribs 126 are formed, which receive forces applied to the edge of the axle receptacle 13 from the pivot axes and distribute them in the housing. Immediately around the axle 13 around the stiffening ribs 126 are kept flat because moving in this area, the pivot lever of the pivot axes. Where possible, for example, adjacent to the end portions for separating the end portions and a central portion of the housing 10 stiffening ribs 126 are arranged, which are formed so high that they touch at the appropriate place in the first housing half shell 11 not shown here stiffening ribs, so that also here abutting surfaces 127 is formed between the two stiffening ribs. In particular, if a joining method is used for both housing half shells 11, 12, in which a connection of the inner abutment surfaces 127 is possible, for example in the aforementioned hot gas welding, so increased rigidity of the housing 10 can be achieved.

In addition 122 centering tabs 128 are arranged in the region of the screw dome, which protrude into corresponding depressions of the first housing half shell 11. If a welding method is used as the joining method, a welding of the housing half-shells 11, 12 can additionally take place at these locations, as a result of which the size of the twisting surface 11, 12 is further increased.

In the housing 10, two drive units 20 are arranged, each having an electric drive motor 21 which acts via a respective gear 22 to a spindle 24a and 24b. Optionally, a brake 23 for the spindle 24a, b is disposed adjacent to the transmission 22, in the present case in each case a loop spring brake. In the housing of the transmission 22 is also a bearing, preferably a roller bearing for the spindle 24a, b arranged.

The gear 22 are presently designed as a worm gear. A rotation of the drive shaft of the drive motor 21 is via a on the drive shaft arranged worm on a preferably helical gear of the transmission 22 transmitted. Said gear is non-rotatably connected to the respective spindle 24 a, b, so that it can be rotated at reduced speed by the drive motor 21. On the transmission 22 each opposite the free end of the spindle 24a, b is a pressure slide 25 is placed, in which the spindle 24a, b retracts. The pressure slide 25 are each slidably mounted in the housing 10 in the x-direction, wherein a rotation of the pressure slide 25 is prevented by the storage.

Inside the pressure slide 25, a spindle nut is arranged non-rotatably, which cooperates with the spindle 24a, b and converts a rotation of the spindle 24a, b in a sliding movement of the corresponding slider 25. At the end of the spindle 24a, b, which is opposite to the associated gear 22, a print head 26 is placed on the pressure slide 25, against which the inserted pivot lever and the force is transmitted to this pivot lever to pivot the pivot axes.

The linearly moving element of the drive unit 20 represents an output member of the drive unit 20. In the present case, the linearly moved element is the spindle nut or an element which is mechanically or materially connected to the spindle nut, ie in the example shown, the pressure slide 25 with the print head 26. Upon rotation of the spindle 24a, b, the spindle nut moves along the threaded spindle 24a, b and, in operation, moves the print head 26 directly or indirectly connected and coupled thereto.

In an alternative embodiment, the output member of the Drehzahlreduziergetriebes, the e.g. may be formed by the worm wheel of the worm gear, a stationary and rotationally driven spindle nut. The spindle is rotatably guided in the case. During rotation of the spindle nut, the spindle represents the linearly moving output member of the drive unit 20. Also, this output member is indirectly or directly coupled to the floating-mounted print head 26 during operation.

In both drive units 20, the same displacement for the pressure slide 25 is provided. In the Figures 3 and 4 In each case, a completely or approximately completely retracted position of the pressure slide 25 is shown, in which the latter is in each case retracted at least approximately completely to the center of the housing 10 (seen in the longitudinal direction x).

Despite the substantially same displacement path of the pressure slide 25 in the two drive units 20, the drive units 20 differ in the length of their spindles 24a and 24b. The length of the spindle 24a is selected so that the required displacement is achieved by the pressure slide 25 and at the same time the drive motor 21 and gear 22 are positioned as close as possible to the corresponding axle 13.

However, the second drive unit 20 has a significantly longer spindle 24b, the length of the spindle 24b is selected at a given distance of the axle 13 so that the drive motors 21 and gear 22 of both drive units 20 are arranged substantially immediately adjacent to each other in the housing 10 , In the present case, for example, only one stiffening rib 126 is arranged between the two drive units.

The different length of the spindle 24a, b leads to a division of the space available in the housing 10, which differs advantageously from known structuring of the interior of the housing of a double drive. Apart from the end regions in which the axle receptacles 13 are arranged, in the present case the interior of the housing 10 is divided into a first installation space 15a, which lies above the spindle 24a, and a second, larger construction space 15b above the spindle 24b.

In known from the prior art double drives both drive units are formed with the shortest possible spindle whose length is comparable to that of the spindle 24a. As a result, apart from the end regions, the available interior of the housing is subdivided into three construction spaces, one each above the spindles and a third installation space between the two drive motors. Accordingly, the space available in the housing according to the prior art in about three equal sections is divided, whereas where it is divided into only two sections, one of which, the space 15 a, a comparable size as the space from the prior Technology, the other (space 15b), however, is about twice as large. Even if the overall available installation space does not increase with the same length of the furniture drive, it is nevertheless less fragmented, which offers greater design freedom in the electrical and electronic components to be arranged in these installation spaces.

It is noted that in the illustrated embodiment, the eccentric arrangement of the drive motors 21 is achieved by different lengths of the spindles 34a and 34b. Equivalent to is an embodiment in which the spindles of both drive units are of equal length, but the output members, e.g. the pressure slide, are different lengths. Combinations of both versions are conceivable.

In the illustrated embodiment 15b a control board 30 is arranged in the larger of the two resulting space. The control board 30 has two areas, which in the FIG. 3 are schematically separated by a dashed line. In the in the FIG. 3 On the right-hand side of the control board 30, a power supply unit 31 is arranged, whereupon a control device 32 is located in the area shown on the left in the figure. The power supply 31 has a power connector 311, in the outside of a power cord can be inserted. The power supply 31, whose electronic components are not shown on the control board 30 for reasons of clarity, is preferably a switching power supply with a high-frequency transformer, which has a smaller footprint compared to a conventional low-frequency transformer, has less weight and is more energy efficient, especially at idle. At an output of the power supply 31 is a low voltage, preferably a DC voltage in the range of 20-30V (volts), for example nominally 24V ready, with the control device 32 and the drive motors 21 are supplied.

By forming the larger packaging space 15 b, a single control board 30 can be used, on the power supply 31 and control device 32 find space. The narrow elongated configuration of the control board 30 allows a secure separation of the mains voltage, which is processed in the region of the power supply 31, and the low voltage, which is supplied to the control device 32.

The control device 32 includes components for driving the drive motors 21. Such components may be electromagnetic switching devices such as relays, or semiconductor switches, for example MOSFET (Metal-Oxide Semiconductor Field-Effect Transistor) transistors or IGBT (Insulated Gate Bipolar Transistor) transistors. The switching devices either have a plurality of contact sets or are connected in the form of an H-bridge, so that the direction of rotation of the drive motors 21 can be switched.

The switching devices are controlled depending on input information of the control board 30, which are for example supplied by an external remote control, also called manual control. For this purpose, 32 externally accessible control terminals 321 are formed in the region of the control device. Furthermore, operating and / or display elements 322 are provided which may, for example, have a key function in order to be able to reset functions of the control device 32. In addition, lighting devices 323, e.g. in the form of light-emitting diodes, be arranged on the control board 30, which illuminate through corresponding openings or windows in the housing half shells 11, 12, the environment of the electromotive furniture drive. In this way, for example, a bedside lighting can be realized, which is active for a certain time after pressing a corresponding button on the remote control, so that a nighttime getting up is facilitated without a room lighting must be turned on.

Furthermore, 30 limit switches 33 are arranged on the control board, which are actuated by a push rod 34 of the pressure slides 25. The limit switches 33 prevent a movement of the pressure slide 25 outside an allowable range, for example, a mechanical stop of the pressure slide 25 on the housing 10 or on the gear 22 and the brake 23 and prevent contact between the end of the spindle 24 a, b and the Pressure plate 26 in the interior of the pressure slide 25. The arrangement of the limit switch 33 directly on the control board 30 reduces the wiring, which would otherwise occur directly in the area of the pressure slide 25 when positioning the limit switch. The transmission of the movement or position of the pressure slide 25 on the limit switch 33 via the tow bars 34 will be described below in connection with the FIGS. 5 to 8 explained in more detail.

FIG. 5 shows an isometric oblique view of the electromotive furniture drive from a lateral oblique position. FIG. 6 also shows an isometric view of a section of the furniture drive in the region of the control board 30 in a slightly oblique view from above side view. The FIGS. 7 and 8th are detailed views of the furniture drive to the area of the control device 32 of the control board 30 with respect to the top of the control board 30 in FIG. 7 or the bottom of the control board 30 in FIG. 8 ,

In the FIGS. 5 to 8 is again like the FIGS. 3 to 4 the first housing half shell 11 (see. FIG. 1 and 2 ) away.

Each of the drive units 20 is associated with a tow bar 34a and 34b. The tow bars 34a, b are made in one piece from plastic in an injection molding process in the illustrated embodiment. In order to achieve sufficient pressure stability despite the length of the tow bars 34a, 34b and to allow a rotationally secure guide within the housing 10, the tow bars 34a, 34b are provided with longitudinally extending guide webs 341. In the housing half shells 11, 12 stiffening ribs 126 in the region of the tow bars 34a, b are formed so that they form a guide for the tow bars 34a, b, in which the tow bars 34a, 34b are guided displaceably in their longitudinal direction. The tow bars 34a, b extend substantially parallel to and above the spindles 24a, b. At each one of its ends a downwardly facing driver 342 is formed, which protrudes into the displacement of the pressure slide 25 and by transverse ribs 254 which are formed on the pressure slides 25, is moved when the pressure slide 25 just before the one or the other end of their permissible displacement.

At the opposite end of the respective tow bar 34a, b, a likewise downwardly facing spring cam 343 is formed. In the area of the spring cam 243, a return spring 35a, b is arranged on the housing 10 for each tow bar 34a, which consists of a w-shaped bent spring plate, which is fixed in a central region on the housing 10 and with lateral spring arms on the side edges of the Spring cam 343 is applied. In addition, a stop positioned between the spring arms for the spring arms is provided on the housing 10, which allows each of the spring arms to move laterally outwardly, but prevents a spring arm from moving further inwardly than in the neutral position shown.

In the example in the FIGS. 6 and 8th clearly recognizable neutral position of the tow bars 34a, 34b is the spring cam 343 - depending on the design of the stop for the spring arms on the housing 10 - either not acted upon by spring force or is applied from both sides equally by the spring arms of the return spring 35a, 35b with spring force that in sum of the return spring 35a, 35b no force acting in one or the other direction of the tow bar 34a, b is exerted.

When moving the tow bar 34a, b in one or the other direction of the return spring 35a, 35b then each acting in the direction of the neutral position restoring force is exerted on the spring cam 343. Accordingly, the tow bar 34a, b assumes the neutral position shown by the return spring 35a, 35b, unless the driver 342 is deflected by one of the transverse ribs 254 of the pressure slide 25 in one or the other direction.

On the upper side of the tow bars 34a, b, switching cams 344 are respectively formed in the end area in which the spring cams 343 are located. The rod-shaped portion of the tow bars 34a, b and the spring cam 343 are arranged below the control board 30, whereas the switching cam 344 are located on the top of the control board 30. The tow bars 34a, b have for this purpose an upwardly pointing longitudinal web, from which the switching cam 344 protrude laterally. In the control board 30, a slot-shaped recess 324 is introduced for the passage of the longitudinal web. The slot-shaped recess 324 is to that in the FIGS. 7 and 8th left side of the control board 30 open to the outside. When assembling the furniture drive, the tow bars 34b, 34a can be threaded into the slot-shaped recess 324 in this order. In addition to the trained in the housing 10 guides for the tow bars 34a, b and the slot-shaped recess 324 in connection with the control cam 344 supporting longitudinal webs provides a guide for the tow bars 34a, b.

On the top of the control board 30 344 limit switches 33a and b are arranged in the region of the switching cam, which are actuated by the switching cam 344. For each of the drive units 20, two limit switches 33a and 33b are provided, wherein the limit switches 33a, b arranged and the switching cam 344 are formed and arranged so that in the respective neutral position of the tow bars 34a, b none of the limit switches 33a, b is actuated , If the respective tow bar 34a, b deflected in one of the directions, in each case one of the two limit switches 33a and the two limit switches 33b is actuated.

On the control board 30, the limit switches 33a, b connected to the switching elements for driving the drive motors 21, that prevents further driving of the respective drive motor 21 upon reaching one of the end positions is, whereas a retraction of the drive motors 21 is possible. For this purpose, for example, each of the limit switches 33a, b be associated with a diode which is connected in parallel with the switching contacts of the limit switch 33a, b.

The not occupied by the control board 30 smaller space 34a is available for other electrical or electronic components. Optionally, for example, be arranged in the space 34 a battery compartment, can be inserted into the externally accessible batteries that can provide the electromotive furniture drive at least temporarily with power in a power failure to allow emergency travel to a desired basic position. As an alternative to a battery compartment accessible from the outside, rechargeable batteries can also be provided in the installation space 34a for emergency travel, which then need not be accessible from the outside and which are kept in a full state of charge via the control board 30 with the aid of a charge control circuit.

Furthermore, for example, receiving modules for a wireless remote control or other optional additional modules, with which the functionality of the control device 32 is supplemented, be accommodated in the installation space 34a. Additionally or alternatively, it is also possible to provide plug connectors on the control board 30 into which supplementary boards can be inserted perpendicular or parallel to the control board 30.

In FIG. 5 is also apparent that the axes of the drive motors 21 are not parallel to the pivot axes, but are tilted relative to these by about 20 to 25 degrees in the yz plane. The tilt is chosen so that a rear end of the motor housing of the drive motors 21 does not project beyond the other height of the furniture drive beyond. Nevertheless, a reduction of the width of the furniture drive in the z-direction is achieved by tilting. The motor dome 125 are in this way less than the side surface 123 over, as it would be in alignment of the motor axis along the z-direction.

In FIG. 9 is a detailed drawing of the pressure slide 25 reproduced with the print head 26 in isometric view. The print head 26 is shown separately from the pressure slide 25 in this figure.

The pressure slide 25 is preferably a one-piece or multi-piece plastic component, which is made of a high-strength and unbreakable plastic, for example, POM (polyoxymethylene). In the present case, the pressure slide 25 is composed of two elements, a hollow base body 251 and a Spindelmuttereinsatz 253. On the main body 251 longitudinally outwardly projecting guide ribs 252 are formed, which also serve to stiffen the base body 251.

It is noted that in a normal operating state of the furniture drive, the drive unit 20 is loaded with load. This can be when the drive motor 21 is switched on, when the load connected to the drive unit 20 is moved, but also when the drive motor 21 is switched off, when the load connected to the drive unit 20 is held. In this normal operating state, the pressure slide 25 is correspondingly also subjected to force. If the pressure slide 25 is constructed in several parts, the individual parts need not necessarily be positively connected to each other. They can also lie on top of each other, whereby they are pressed against each other in an axial force-locking manner by the force built up by the load. In that case, a lateral guide is preferably provided for each of the parts in the housing 10. The surfaces with which the various parts of the pressure slide 25 abut each other may be flat surfaces or surfaces which in turn are convex or concave (ie crowned), so that between the various parts of the pressure slide 25, an angle compensation is possible.

In an end region of the main body 251 of the Spindelmuttereinsatz 253 is used. A threaded portion is formed centrally in the spindle nut insert 253, which serves as a spindle nut for the spindle 34a, b. The threaded portion projects into the interior of the main body 251. At the in FIG. 9 visible outside the spindle nut insert 253 protrudes plate-shaped beyond the opening in the base body 251 and is located on its end face. In this way, large forces can be transmitted from the spindle nut insert 253 to the main body 251. The plate of the spindle nut insert 253 also provides an over the main body 251 outwardly projecting transverse rib 254, which serves as a stop for the driver 342 of the tow bar 34a, b. Another transverse rib 254 is formed for this purpose on the opposite side of the main body 251.

The basic shape of the main body 251 varies along its longitudinal extent from a hollow cylinder on the side of the spindle nut insert 253 to a Hollow cone on the opposite end of the main body 251. The transition between the two basic forms takes place approximately in the middle of the main body 251. At the end opposite the spindle nut insert 253, the diameter of the main body 251 widens.

In the widened opening of the main body 251 of the plate-shaped print head 26 is used here. This has a pressure plate 261 with an outwardly facing pressure surface 262 on which abuts the pivot lever of the pivot axis of the furniture. On the opposite side of the pressure plate 261, a nozzle 264 is formed, which projects into the opening of the main body 251 of the pressure slide 25 inside. The pressure plate 261 projects outwardly beyond the connecting piece 264, so that a bearing surface 263 is formed, with which the printing head 26 rests against an end-face bearing surface 255 of the pressure slide 25. Printhead 26 and pressure slide 25 engage with each other, in the present example on the printhead 26 latching hooks 265 are formed, which are used in detent guides 256, and each engage with undercut latching projections 257.

The geometry and dimensions of the nozzle 264 are selected so that the print head 26 can be displaced in the y- and / or z-direction relative to the pressure slide 25. In the illustrated embodiment, there is a margin for shifting in the z-direction. When moving the Drucckopf 26 performs no linear movement, but a pivoting movement. This is achieved by appropriate shaping of the support surface 255 of the base body 251 on the one hand and the support surface 263 of the print head 26 on the other. The support surface 255 of the pressure slide 25 is concave in the z-direction, whereas the support surface 263 of the print head 26 is convex in the z-direction. The pivotal movement allows an angle compensation, if a pivot lever is not aligned with its support surface exactly along the z-direction.

The possible angular movement is in FIG. 10 in a plan view of the end portion of the pressure slide 25 with attached printhead 26 shown in three sub-figures. In the middle part of the figure (b) the FIG. 10 the printhead 26 is in a central position relative to the pressure slide 25. To enable movement of the print head 26, the latching hook guide 256 is slightly wider than the width of the latching hook 265 itself. In the subfigure (b), the latching hook 265 is located centrally in FIG the latching hook guide 256. The left part of the figure (a) shows the pressure plate 26 seen from the pressure slide 25 from deflected to the left and pivoted. The sub-figure (c) shows the pressure plate 26 as seen from the pressure slide 25 pivoted to the right. The freedom that the latching hook 265 has in the latching hook guide 256 is adapted to the clearance of the connecting piece 264 in the opening of the base body 251, such that a stop for the print head 26 is preferably formed by abutment of the connecting piece 254 against the wall of the base body 251 is because this attack can absorb greater forces than the latching hook 265th

As in particular in FIG. 5 can be clearly seen, also pressure surface 262 of the print head 26 may not be flat. In the present case, the pressure surface 262 is slightly chamfered in the upper region in order to prevent the abutment of this section of the pressure surface 262 on the pivot shaft.

From the extension of the spindle 24b against the spindle 24a and the correspondingly changed arrangement of the drive motors 21 and gear 22 to each other also results in an advantage in the packaging of several of the illustrated electromotive furniture drives over the prior art. By the extension of the spindle 24b relative to the spindle 24a, the drive motors 21 are positioned close to each other, so that a single motor dome 125 can be formed on the second housing half shell 12, comprising both housings of the drive motors 21. This motor dome 125 is also not centrally located on the longitudinal side of the housing 10, but off-center. The eccentric arrangement makes it possible to position two furniture drives, each with facing each other second housing half-shells 12 within a packaging unit, with little or, depending on the geometry, no displacement of the furniture drives each other must be longitudinally.

This is in the FIG. 11 exemplified for ten arranged in pairs in a position of a packaging unit 40 furniture drives. Due to the eccentric arrangement of the motor dome 125 on the housing 10 of the furniture drives these pairs can be arranged interlaced, without that they have to be shifted significantly in the longitudinal direction against each other. In this way, the available storage space in the packaging unit 40 is optimally utilized. In the illustrated example, the packaging unit 40 is based on a Euro pallet 41, on which a box 42 is placed. In the carton 42 several of the illustrated layers of furniture drives can be packed one above the other. In order to be able to stack two or more packaging units 40, if necessary, inside the box 42 vertical support rollers 43 arranged distributed, which may for example consist of cardboard material like the cardboard 42.

LIST OF REFERENCE NUMBERS

10

casing

11

first housing half shell

111

clamp recess

112

screw

113

side surface

114

connection cavity

12

second housing half shell

121

clamp recess

122

screw boss

123

side surface

124

connection cavity

125

engine dome

126

stiffening ribs

127

abutting face

128

centering bracket

13

Axle mount for swivel axis of the furniture

14

pusher

15a, b

space

20

drive unit

21

drive motor

22

transmission

23

brake

24a, b

spindle

25

pressure slide

251

body

252

guide web

253

Spindle nut use

254

Transverse rib (stop for driver)

255

convex bearing surface

256

Latch hook guide

257

catch projection

26

printhead

261

printing plate

262

print area

263

concave bearing surface

264

Support

265

latch hook

30

control boards

31

power adapter

311

mains connection

32

control device

321

control connection

322

Operating or display element

323

lighting element

324

recess

33a, b

Limit switches

34a, b

tow bar

341

guide web

342

takeaway

343

spring cam

344

switching cams

35a, b

Return spring

40

Packaging Unit

41

euro pallet

42

carton

43

supporting role

Claims (11)

1. An electromotive furniture drive for adjusting at least one furniture part of a piece of furniture comprising at least one drive unit (20), which has a drive motor (21), a gearing (22), and a spindle drive, which acts on a pressure slide (25) displaceable along a displacement path, wherein the main body (251) of the pressure slide (25) is associated with a floating-mounted pressure head (26), characterized in that the pressure head (26) is mounted on the main body (251) of the pressure slide (25) in such a way that it is movable in a pivot movement on a circular path.
2. The electromotive furniture drive according to Claim 1, in which the main body (251) has a convex support surface (255) and the pressure head (26) has a concave support surface (263), using which the main body (251) and the pressure head (26) bear on one another.
3. The electromotive furniture drive according to Claim 1 or 2, in which the main body (251) is hollow-cylindrical in a first portion of its longitudinal extension and is hollow-conical in a second portion of its longitudinal extension.
4. The electromotive furniture drive according to Claim 3, in which a threaded portion, which is used as a spindle nut, is integrally formed in the hollow-cylindrical portion of the main body (251).
5. The electromotive furniture drive according to Claim 3, in which a spindle nut insert (253) having a threaded portion, which is used as a spindle nut, is inserted into the hollow-cylindrical portion of the main body (251).
6. The electromotive furniture drive according to any one of Claims 2 to 5, in which the pressure head (26) has a pressure plate (261), comprising an outer side, which is formed as a pressure surface (262) for the contact of the pivot lever, and an inner side facing toward the main body (251), on which a central support (264) is formed, which is radially enclosed by the concave support surface (263).
7. The electromotive furniture drive according to Claim 6, in which the central support (264) is inserted into the main body (251), wherein a movement play is provided in the case of movement in at least one spatial direction.
8. The electromotive furniture drive according to any one of Claims 1 to 7, in which the main body (251) and the pressure head (26) have detent means for the latching connection with one another.
9. The electromotive furniture drive according to Claim 8, in which the pressure head (26) has at least one detent hook (265) and the main body (251) has at least one detent projection (257).
10. The electromotive furniture drive according to any one of Claims 1 to 9, in which guide ribs (251) extending in the longitudinal direction are formed on the main body (251).
11. The electromotive furniture drive according to any one of Claims 1 to 10, in which the main body (251) and/or the pressure head (26) has transverse ribs (254), which are used as stops for drivers (242) for actuating end position switches (33a, 33b).

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