Electro-motoric drive for furniture and piece of furniture having such a drive

0001The invention relates to an electromotive furniture drive for adjusting movable furniture parts of a functional piece of furniture, comprising a control device, at least one adjustment drive with an electric motor and at least one evaluation circuit with an input, which can be electrically conductively connected together with a sensor attached to the functional piece of furniture and an approximation and / or forms a touch detector. The invention also relates to functional furniture with such an electromotive furniture drive.

0002Electromotive furniture drives of this type are known and include, for example, a number of adjustment drives, for example linear drives. A linear drive generates a linear movement on an output member and has at least one electric motor, a gear train and the output member, the gear train with the output member being connected downstream of the electric motor. The linear drive and its output element are connected to furniture components and move or adjust these relative to each other when the motors are operating. The furniture components are movably connected, for example, to a base frame and / or to one another by so-called functional or movement fittings. These fittings are usually made of metallic materials such as steel.

0003A functional piece of furniture is provided with at least one electromotive furniture drive. Such an electromotive furniture drive is mounted in the furniture, which has fixed and movable furniture components. Fixed furniture components are, for example, frame components. Movable furniture components are, for example, firm or resilient support surfaces of upholstery or a mattress of the seating and / or reclining furniture, and sections or elements of the furniture which can be adjusted manually or by an electric motor.

0004The electromotive furniture drive is used to adjust the movable furniture components. The adjustment movement and driving force generated by the electromotive furniture drive is transmitted to the respective movable furniture component, the electromotive furniture drive being supported on a fixed furniture component and adjusting the movable furniture component relative to the fixed furniture component. The electromotive furniture drive can also be attached between two movable furniture components, whereby it can be adjusted relative to one another.

0005Electromotive furniture drives are known from the prior art in a variety of different designs for different applications and purposes, for example as single drives, double and multiple drives.

0006Control devices are also known which are designed to control the respective electric motor of an adjustment drive on command or as a result of an event, for example a control command from a manual control, a limit switch, a detector, etc. The control devices have inputs and outputs. The outputs are electrically conductively connected to the respective electric motor, for example. The inputs are, for example, with manual remote controls or, if necessary via evaluation circuits, electrically conductively connected to sensors and detectors. Other control devices have other outputs which exclusively transmit an electrical or an electromechanical signal to a further control device which have the previously described outputs for operating the respective electric motor.

0007In particular, the control devices described at the outset have proven their worth. From the publication<patcit id="pcit0001" dnum="DE29707795U1"><text>DE 297 07 795 U1</text></patcit> a control device with an input is known, the input being electrically conductively connected to a metallic functional fitting, for example via a connecting line. The functional fitting or parts of the functional fitting forms / form a detector together with an evaluation circuit of the control device and the connecting line. The evaluation circuit of the control device determines the level of the electrical capacity of the functional fitting with respect to a reference variable, for example the floor, via said connecting line. Furthermore, the control device determines the change over time in the measured variable of the electrical capacitance detected by the evaluation circuit. Rapid changes in the electrical capacity of the functional fitting during operation of the motor indicate a fault, for example the occurrence of an impending or impending pinching of an object or a body part, provided a person or object moves into or touches a danger zone of the functional fitting. The respective electric motor is then switched off and, if necessary, reversed for a short period.

0008The term "functional fitting" also includes metallic frames and parts, such as feet, of functional furniture. The term "sensor" here means an element of a functional fitting or a separate, electrically conductive element, such as a cable, rod antenna, flat iron, etc., which is attached to the furniture.

0009The control device mentioned at the outset has proven its worth. However, there is a disadvantage with large pieces of furniture, such as with wide beds or with complex pieces of furniture, such as when the functional fittings are divided into several groups.

0010Several groups can be formed if, for example, in a bed an upper frame is connected to a lower frame via electrically insulating rollers or sliders. A further group can be formed if a foot flap fitting section of a functional fitting of an armchair with plastic bearings is arranged in an electrically insulated manner from the base frame. Other groups can be formed if the piece of furniture has a plurality of functional fittings, which are each used for partial areas of the piece of furniture.

0011In order to provide protection against jamming for all movable furniture parts, according to the prior art, all movable furniture parts or all sections of all functional fittings of the furniture must be electrically connected to one another via flexible lines. Although this method has also proven itself, the effort of the control device is very high, which is reflected in the high quality and the assembly effort of the electrical measuring circuit. It has also turned out that a complex adjustment of the system is necessary to prevent false triggering of the pinch protection.

0012The invention is based on the object of providing an electromotive furniture drive with a control device of the type mentioned, the disadvantages described no longer occurring or being reduced significantly, and which is also easy to assemble and is easy to handle.

0013The task is solved by arranging more than one proximity and / or touch detector on a functional piece of furniture. A sensor or a group of sensors with an evaluation circuit forms such a detector, each sensor or group of sensors being connected to an input of the evaluation circuit. In an inventive manner, the piece of furniture has a plurality of detectors, which are individually connected in an electrically conductive manner to an input of the evaluation circuit of the control device.

0014The design of the various detectors makes it possible to reliably monitor even a large functional fitting, such as the bed shown as functional furniture, without having to ensure that furniture parts to be monitored are galvanically connected to one another or that there is sufficient capacitive coupling of the furniture parts is given among themselves. The division of the movable furniture parts to be monitored in a functional piece of furniture for anti-trap protection into at least two groups, which are assigned to different detectors, also prevents unwanted false responses due to interference radiation, which could otherwise be coupled in more easily if the sensor surface is otherwise too large.

0015The control device has an evaluation circuit with a plurality of at least two inputs, each input being coupled to a sensor or a group of sensors. In addition, the evaluation circuit has a multiplexer, via which the at least two inputs can be connected sequentially to a detector circuit of the evaluation circuit. This measure of dividing into several groups combined with a sequential evaluation with only one detector circuit enables inexpensive manufacture and easy assembly of a highly sensitive pinch protection with high operational reliability.

0016In an advantageous embodiment of the electromotive furniture drive, the sensor or the group of sensors is conductively connected to one of the inputs of the at least one evaluation circuit. Alternatively, the sensor or the group of sensors is capacitively coupled to one of the inputs of the at least one evaluation circuit.

0017In a further advantageous embodiment of the electromotive furniture drive, the sensor is a sensor line and / or a conductive movable furniture part and / or a conductive element of a functional fitting.

0018A functional furniture according to the invention has at least two groups of movable furniture parts and at least one electromotive furniture drive according to one of the preceding claims. The advantages mentioned above in connection with the furniture drive result.

0019The invention is explained in more detail below using an exemplary embodiment with the aid of figures. Show it:<dl id="dl0001"><dt>Fig. 1</dt><dd>a schematic perspective view of an exemplary furniture arrangement; and</dd><dt>Fig. 2</dt><dd>a block diagram of the components of the furniture arrangement.</dd></dl>

0020<figref idref="f0001">Fig. 1</figref> shows an exemplary furniture arrangement with a functional furniture 1. As a functional furniture 1, a bed is shown here as an example. The functional furniture 1 has a basic element 2, here a frame-like frame with feet. A slatted frame with a functional fitting 3 is inserted into the base element 2. The slatted frame carries a mattress M.

0021In the example shown, the functional furniture 1 has two movable furniture parts 5 and 6, which can be moved relative to a fixed base part 4 arranged between them. Specifically, the two movable furniture parts 5, 6 are a back part and a leg part. For the sake of simplicity, they are also referred to below as back part 5 and leg part 6.

0022The movable arrangement of the movable furniture parts 5 and 6 is realized by the functional fitting 3, also called a movement fitting. The movement is displaceable and / or pivotable.

0023The movably mounted back part 5 and the leg part 6 are each coupled to an electromotive adjustment drive 7, 8. The back part 5 is coupled to the electromotive adjustment drive 7. The electromotive adjusting drive 8 is provided for moving or adjusting the leg part 6.

0024The electromotive adjustment drives 7, 8 are designed here as linear drives. The linear drives have one or a number of electric motors, each motor being followed by a speed reduction gear with at least one gear stage. The speed reduction gear can be followed by a further gear, for example in the form of a threaded spindle gear, which generates a linear movement of the output member from the rotational movement of the motor. The last transmission link or a further link connected to it forms an output link. The output member of the respective electromotive adjustment drive is connected to the respective furniture component (back part 5, leg part 6) or alternatively to a component connected to the base frame 2, so that when the electric motor of the respective adjustment drive 7, 8 is in operation, the movable furniture components are adjusted relative to one another will.

0025The electromotive adjustment drives 7, 8 are connected to a control device 9. This connection can be made, for example, as a pluggable cable connection, which is not shown here. The control device 9 has an electrical supply unit, which provides the electrical energy, for example from the network, for the electromotive adjusting drives 7, 8. For this purpose, the control device 9 in this example can be connected to a power connector with a power connector via a power cord (not shown). The mains plug conducts the mains voltage on the input side to the electrical supply unit of the control device 9, which on the secondary side emits a low voltage in the form of a DC voltage and forwards it to a motor controller.

0026As an alternative to this, the control device 9 is connected upstream of a line-dependent voltage supply, also not shown, with a mains input and with a secondary-side low-voltage output, which supplies the low-voltage in the form of a DC voltage via a line.

0027An operating unit 20 is also assigned to the furniture 1, with its operating elements 21 the electromechanical adjusting drives 7, 8 can be controlled via the control device 9. When an operating element 21 is actuated, a control signal for controlling the respective electromechanical adjustment drive 7, 8 is transmitted to the control device 9 wirelessly or by wire via a transmission link.

0028The control device 9 has switching elements which convert the control signals of the transmission link into switching signals for switching the respective adjustment drive 7, 8. The switching elements can be, for example, relay switches and / or semiconductor switches. The manually operable control elements 21 of the control unit 20 generate control signals which are converted by the receiver of the control device 9 into control currents for the switching elements. In the case of a wired control unit 20, the control elements 21 switch the control current of the relay switches or the semiconductor switches. In both cases, the circuit breakers of the relay switches or the semiconductor switches switch the high motor current of the respective electromotive adjusting drive 7, 8.

0029In order to prevent a body part from getting caught when moving the movable furniture parts 5, 6, the functional furniture 1 shown is equipped according to the application with proximity and / or touch detectors, which prevent actuation of the adjusting devices 7, 8 via the control device 9 when approaching one Sensor or a touch of the sensor is detected. This is discussed below in connection with<figref idref="f0002">Fig. 2</figref> explained in more detail.

0030<figref idref="f0002">Fig. 2</figref> shows the system of <figref idref="f0001">Fig. 1</figref> in a schematic block diagram. The same reference numerals in this figure denote the same or equivalent elements as in<figref idref="f0001">Fig. 1</figref>.

0031As related to <figref idref="f0001">Fig. 1</figref> is described, the furniture fitting has the two movable furniture parts, the back part 5 and the leg part 6, which are movable relative to a fixed base part 4. The movement is achieved via the two electromotive adjusting drives 7, 8, which act on the back part 5 and the leg part 6. The mechanical coupling of the adjustment drives 7, 8 on the back or leg part 5, 6 is with the<figref idref="f0002">Fig. 2</figref> symbolized only by a dashed line. The adjustment drives 7, 8 are controlled by the control device 9 and supplied with current. A power supply to the control device 9, for example via an integrated or external power supply unit, is shown in FIG<figref idref="f0002">Fig. 2</figref> not shown.

0032In order to prevent a body part from being pinched when moving one of the movable furniture parts 5, 6, for example between the movable furniture part 5, 6 and a fixed part of the functional furniture 1, an evaluation circuit 10 is provided which touches one of the movable furniture parts 5, 6 detected. In the example shown, the evaluation circuit 10 is arranged externally by the control device 9 and is electrically connected to it via an output 13 of the evaluation circuit 10. In alternative configurations, the evaluation circuit 10 can be integrated in the housing of the control device 9.

0033In the example shown, the evaluation circuit 10 has two inputs 11, 12 which are coupled to the furniture parts 5, 6 via sensor lines 111, 121. Correspondingly, two sensor groups are formed, each of which comprises the sensor line 111 or 121 and the furniture part 5, 6. Together with the evaluation circuit 10, two independent contact and / or proximity detectors are formed as anti-trap protection.

0034Touching or approaching the furniture parts 5, 6 is detected by the evaluation circuit 10 via the sensor lines 111, 121. A signal is generated at an output 13 of the evaluation circuit 10, which causes the control device 9 to stop at least one of the two adjustment drives 7, 8. It can be provided that a touch of the furniture part 5 or Approaching the furniture part 5 only stops the assigned adjustment drive 7, whereas the detection of touching the furniture part 6 or approaching the furniture part 6 via the sensor line 121 stops the assigned adjustment drive 8. However, preferably each touch, regardless of which sensor line 111, 121 or which of the inputs 11, 12 detects the evaluation circuit 10, leads to a stopping of any adjustment drives 7, 8 which may be actuated simultaneously.

0035In a further development it can also be provided that the adjustment drives 7, 8 are not only stopped, but that a moving adjustment drive 7, 8 is operated in the reverse direction of movement for a predetermined short period after stopping, in order to release a body part that may already be jammed .

0036The detection of touching of the sensors by the evaluation circuit 10 is preferably capacitive. This capacitive contact or proximity detection can be set so sensitively that no direct galvanic contact of an input 11 or an exposed section of the sensor line 111, 121 is required, but rather a contact or approach to isolated sections of the sensor line 111 or the furniture parts 5, 6 coupled therewith or also sections of a functional fitting coupled therewith can be detected. In this way, detection of contact with a painted or plastic-coated area of ​​the movable furniture parts 5, 6 is made possible.

0037If moving elements to be monitored, for example the furniture parts 5, 6 or other sections of functional fittings, are made entirely of an insulating material, for example wood or plastic, a conductive element can be applied. The conductive element can consist in the continuation of the sensor line 111, 121 itself. Alternatively, metallized foils can, for example, be glued to the non-conductive material. Furthermore, it is possible to make an insulating material with a conductive coating, for example based on a conductive polymer, superficially conductive. Fabrics or yarns with woven-in metallic threads or fibers can also be used as conductive elements.

0038In the <figref idref="f0002">Fig. 2</figref> Two different types of coupling of the sensor lines 111, 121 to the movable furniture parts 5, 6 are shown as examples. The sensor line 111 makes direct contact with the furniture part 5 in a conductive connection 112. If the furniture part 5 is a painted steel tube, the paint can be removed at one point, for example, and the sensor line 111 can be attached at this point. Alternatively, for example, a self-tapping screw can be screwed into the metal tube of the furniture part 5, via which the conductive connection 112 takes place.

0039In contrast, the sensor line 121 is coupled to the furniture part 6 via a capacitive coupling 122. For this purpose, the sensor line 121 has a flat electrode at its end, which is glued to a painted area of ​​the furniture part 6, for example by means of a self-adhesive layer. The change in capacitance of the furniture part 6 by approaching or touching a body part is transmitted through this capacitive coupling 122 to the sensor line 121 and thus to the evaluation circuit 10.

0040In the illustrated embodiment of the <figref idref="f0002">Fig. 2</figref> two inputs 11, 12 and two corresponding sensor lines 111, 121 are provided by way of example. It is understood that this number is purely exemplary. It is also possible to provide more than the two sensor lines 111, 121 shown, by means of which more than two groups of monitored movable furniture parts 5, 6 on the functional furniture 1 are defined.

0041The design of the various detectors makes it possible to reliably monitor even a large functional fitting, such as, for example, in the bed shown as functional furniture 1, without having to ensure that furniture parts 5, 6 to be monitored are galvanically connected to one another or that they are sufficient capacitive coupling of the furniture parts to one another is given. The division of the movable furniture parts 5, 6 to be monitored in a functional piece of furniture for an anti-trap protection into at least two groups, which are assigned to different detectors, also prevents an undesired false response due to interference radiation, which can be more easily coupled in if the sensor surface is otherwise too large.

0042In the evaluation circuit 10 can internally have a single detector circuit for the change in capacitance, which is connected in a multiplex process to the at least two inputs 11, 12 in rapid alternation (sequential evaluation). This measure of dividing into several groups and the sequential evaluation with only one detector circuit enables inexpensive production and easy assembly of a highly sensitive pinch protection with high operational reliability at the same time.

0043Alternatively, the evaluation circuit 10 can have a number of detector circuits for a change in capacitance corresponding to the number of inputs 11, which are coupled to one another on the output side via a corresponding logic circuit, for example a "or" link, so that when each of the detector circuits responds, a corresponding output signal at the output 13 is output. Around the evaluation circuit 10 universally for a plurality of functional fittings or To be able to use furniture, a larger number of inputs 11, 12 can be provided, for example four inputs 11, 12, which also offers a sufficient number of groups for larger functional fittings.

0044When using such an evaluation circuit in furniture which only requires two or three monitored groups, inputs 11, 12 which are not used can be set inactive, for example by connection to a ground potential. Alternatively, individual inputs 11, 12 can be selectively deactivated by parameterizing a multiplexer used on the input side or a logic used on the output side in the evaluation circuit 10.

0045The detector circuits for detecting a change in capacitance are preferably self-adjusting, so that a slow change in capacitance, which is caused, for example, by changing environmental conditions such as changing air humidity, does not lead to false triggering. The sensor lines 111, 121 are preferably ordinary single-core lines without shielding, which are inexpensive and can be easily installed.

0046If several control devices are provided on one functional piece of furniture, one evaluation circuit each can be assigned to one control device.

Reference numerals

0047<dl id="dl0002" compact="compact"><dt>1</dt><dd>Functional furniture</dd><dt>2</dt><dd>Basic element</dd><dt>3</dt><dd>Functional fitting</dd><dt>4</dt><dd>fixed base</dd><dt>5</dt><dd>movable furniture part (back part)</dd><dt>6</dt><dd>movable furniture part (leg part)</dd><dt>7, 8</dt><dd>Adjustment drive</dd><dt>9</dt><dd>Control device</dd></dl><dl id="dl0003" compact="compact"><dt>10</dt><dd>Evaluation circuit</dd><dt>11, 12</dt><dd>entrance</dd><dt>111, 121</dt><dd>Sensor cable</dd><dt>112</dt><dd>conductive connection</dd><dt>122</dt><dd>capacitive coupling</dd><dt>13</dt><dd>exit</dd></dl><dl id="dl0004" compact="compact"><dt>20</dt><dd>Control unit</dd><dt>21</dt><dd>Control element</dd></dl><dl id="dl0005" compact="compact"><dt>M</dt><dd>mattress</dd></dl>