ELECTRICALLY ADJUSTABLE FURNITURE PIECE COMPRISING A DRIVE MOTOR

Abstract

In a furniture piece including a furniture support part and an adjustable furniture part which is movable relative to the furniture support part by an electric drive motor, the electric drive motor is operable by a power supply at the power supply net voltage without galvanic separation between the power supply and the electric drive motor. The furniture pieces also include sensors for sensing motions of the furniture parts which motions are analyzed and compared with reference patterns to determine an occupation state of the furniture pieces.

Claims

1. An electrically adjustable furniture piece including at least one electric drive motor (4) for adjusting at least one adjustable furniture part (3) relative to a furniture support part (2) of the furniture piece (1), wherein the drive motor (4) is an electric motor operable by a power supply voltage without galvanic separation between the power supply net and the drive motor (4).

2. The furniture piece as claimed in claim 1, wherein an operating unit for switching the drive motor (4) on and off, for recalling stored positions and a height indication is integrated into the housing of a controller (13) for at least one electric drive motor (4)

3. The furniture piece as claimed in claim 2, wherein the operating unit for switching the drive motor (4) on and off comprises a light source and a phototransistor or cooperates with a light source.

4. The furniture piece as claimed in claim 2, wherein the operating unit for switching the drive motor (4) on and off is a radio module for a signal transmission to the controller (13).

5. The furniture piece as claimed in claim 2, wherein the controller (13) is provided with a communication port for a configuration of the controller (13) via an external, connectable apparatus.

6. The furniture piece as claimed in claim 1, wherein the drive motor (4) is one of an universal motor, a permanent magnet excited collector motor and a brushless DC motor.

7. The furniture piece as claimed in claim 1, wherein at least two electric drive motors (4) are arranged in the furniture piece (1) for adjusting the adjustable furniture part (3) with respect to the furniture support part (2).

8. The furniture piece as claimed in claim 7, wherein the least two electric drive motors (4) are controllable independently of one another.

9. The furniture piece as claimed in claim 7, wherein a common controller (13) is provided for the at least two electric drive motors (4).

10. The furniture piece as claimed in claim 7, wherein at least one of the at least two drive motors (4) is controllable exclusively dependent on sensor signals generated by Hall sensors whereas the other drive motor or motors are controllable exclusively by an evaluation of gyro/gravitation sensor signals.

11. The furniture piece as claimed in claim 1, wherein the furniture piece is provided with a sensor arrangement (7) determining a position or movement of an adjustable furniture part (3) and at least one drive motor (4) is controllable depending on the position or movement determined by the sensor arrangement (7).

12. A method for operating at least one of the furniture pieces (1) as claimed in claim 1, wherein at least two electric drive motors (4) arranged in one or in several furniture pieces (1) are synchronized via the power supply net.

13. A method for determining an occupation state of a furniture piece (1) according to claim 1, with a sensor arrangement (7) for detecting a movement of an adjustable furniture part (3) of the furniture piece (1) wherein the furniture piece (1) is determined to be occupied by a person and an occupation signal (12) is generated if it is determined via the sensor arrangement (7) that a movement pattern of the adjustable furniture part (3) corresponds to a particular reference pattern normally generated when the furniture piece is occupied.

14. The method according to claim 13, wherein via the sensor arrangement (7) an absolute movement of the movable furniture part is detected.

15. The method according to claim 13, wherein the furniture part (3) the movement of which is sensed by the sensor arrangement (7) is an adjustable furniture part (3) which is adjustable with respect to a furniture support part (2) of the furniture piece (1) and wherein a relative movement of the adjustable furniture part (3) with respect to the furniture support part (2) is detected by the sensor arrangement (7).

16. The method according to claim 15, wherein the furniture piece (1) includes at least one electric drive motor (4) for adjusting the adjustable furniture part (3) with respect to the furniture support part (2), and the movement pattern of the adjustable furniture part (3) for detecting the occupation state of the furniture piece (1) is detected during a resting phase of the electric drive motor (4).

17. The method according to claim 15, wherein the furniture piece (1) includes at least one electric drive motor (4) for adjusting the adjustable furniture part (3) with respect to the furniture support part (2) and the movement pattern of the adjustable furniture part (3) for detecting the occupation state of the furniture piece is detected during an adjustment movement by the electric drive motor (4).

18. The method according to claim 15, wherein the furniture piece (1) is in the form of a table with a height-adjustable table plate forming the adjustable furniture part (3) and at least one table leg forming the furniture support part (2), and wherein the movement pattern of the table plate (3) is detected with the aid of the sensor arrangement (7).

19. The method according to claim 13, wherein an inclination change of the adjustable furniture part (3) is detected by the sensor arrangement.

20. The method according to claim 13, wherein the occupation signal (12) of the furniture piece (1) is supplied to a central location (9).

21. The method according to claim 13, wherein depending on the occupation state of the furniture piece (1) at least one technical device (11) associated with the furniture piece (1) or arranged nearby is controlled.

22. The method according to claim 20, wherein the occupation state of several furniture pieces (1) is determined of which each is provided with a sensor arrangement (7) for determining an adjustment movement of the adjustable furniture part (3) and the occupation signals (12) of occupied furniture pieces (1) are supplied to the central location (9).

23. The method according to claim 22, wherein in the central location (9) at least one of the non-occupied furniture pieces (1) is assigned to at least one person.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0059] It is shown in:

[0060] FIG. 1, in a side view, a section of an adjustable table with a table plate which is height-adjustable with respect to a table leg,

[0061] FIG. 2 the table section with the table plate raised,

[0062] FIG. 3 the complete table in a side view showing an electric drive motor in both, the left and right table legs,

[0063] FIG. 4 a schematic representation of several tables with a transmission of the occupation state of each table to a central unit,

[0064] FIG. 5 a perspective view of a controller for controlling an electric drive motor, and;

[0065] FIG. 6 a longitudinal sectional view of the controller.

DESCRIPTION OF A PARTICULAR EMBODIMENT

[0066] Identical components shown in the various figures are designated by the same reference numerals.

[0067] In FIGS. 1 and 2 as an exemplary furniture piece a table 1 is shown with a table plate 3 supported on a table leg 2. The table leg 2 forms the furniture support part and the table plate 3 forms the adjustable furniture part, wherein the table plate 3 is height adjustable with respect to the table leg 2. The table plate 3 is height-adjustable by an electric drive motor 4, which is arranged at the bottom side of the table plate 3 and mounted on a guide member 3a which extends into the table leg 2 and is slidably guided therein. The drive motor 4 rotates a worm gear shaft 5 which extends into a counter thread in the table leg 2 so that a desired height adjustment of the table plate 3 is achieved by a rotation of the shaft 5.

[0068] At the bottom side of the table plate 3 there is a control arrangement 6 for controlling the electric drive motor 4. The control arrangement comprises a controller and a sensor arrangement 7 whose sensor signals are processed in the controller to provide control signals by which the drive motor 4 is controlled. The electric drive motor 4 can be controlled to rotate in either direction of rotation in order to either raise the table plate 3 or lower it.

[0069] The sensor arrangement 7 includes for example a gyroscope sensor for determining the inclination of the table plate 3 with respect to the table leg 2 or an absolute pivot movement of the table plate, and a gravitation sensor which provides an absolute inclination value. The height of the table plate 3 can be determined via a distance sensor which measures the distance from the floor, from a reference or from the ceiling. Also the distance sensor may be part of the sensor arrangement 7.

[0070] In FIG. 3 the whole table 1 is shown in a side view wherein two table legs 2 are visible which together support the table plate 3. Into each of the table legs 2 a guide member 3a extends from the bottom side of the table plate 3 and each guide member 3a carries an electric drive motor 4, via which the respective guide member 3a can be height-adjusted with respect to the table leg 2. The two electric drive motors 4 are both controlled by the control arrangement 6 which includes a sensor arrangement 7 that operates without contact. The over-all control via the sensor arrangement 7 occurs via a manual gesture in a sensing area indicated by the arrow 8 above the sensor arrangement 7 and the upper side of the table plate 3.

[0071] The two electric drive motors 4 may be controlled via the common control arrangement 6 in a synchronous manner. But an independent control of the two electric drive motors 4 is also possible. This makes it possible to adjust the table plate 3 to a desired inclination for example to adjust the table plate 3 to a horizontal orientation in spite of an uneven floor or to a certain desk inclination. If several sensors are arranged in the sensor arrangement 7 correspondingly more degrees of freedom of movement of the table plate 3 can be determined and adjusted to the desired values by the various drive motors.

[0072] The electric drive motors 4, which are provided on the table 1 in the earlier described exemplary embodiments, are preferably motors which are operated by the public electric power supply without galvanic separation between the electric power supply and the drive motors. Such drive motors, which are connected to the normal power supply net, have the advantage that a transformer is not needed. However the motor may also be operated via a power electronic device with a lower power supply voltage. The control arrangements or, respectively, controllers can have smaller dimensions. Furthermore less waste heat is produced in spite of a higher performance so that the availability of the electric drive motors is increased.

[0073] The drive motors may be for example universal motors, permanent magnetized collector motors or brushless DC motors.

[0074] Various electric drive motors, in particular in different furniture pieces may, based on their design as power supply motors, be synchronized via the power supply net. This has the advantage that the drive motors can be synchronized also over larger distances without the need for communication cables.

[0075] FIG. 4 shows an exemplary embodiment including a plurality of furniture pieces 1, each in the form of a table with a height adjustable table plate. Via the sensor arrangement in each table, the momentary occupation state that is the occupation of a table by a person can be determined for each table. To this end, the sensor information of the sensor arrangement in each table 1 is evaluated by a comparison with a reference movement pattern. The data collection via the sensor arrangement in each table 1 occurs over a minimum period in order to obtain a sample movement of the adjustable furniture part in the form of the table plate, from which the momentary occupation state information is derived.

[0076] As soon as a person is sitting or standing at a table and applies a load to the table plate which is typical for office work, such as placing their arms onto the table plate and/or writing on the table plate a movement pattern is developed which is typical for the particular activity and which is sensed by the sensor arrangement provided on the table plate. The sensed movement pattern is compared with a reference movement pattern and if there is sufficient conformity between the sensed movement pattern and the reference movement pattern it is concluded that the table is occupied by a person. This reference movement pattern which is typical for an occupied table differs from a movement pattern that is for example generated during raising or lowering the table plate during an adjustment of the table plate inclination or an accidental jolt to the table plate. It is as a result possible to distinguish different movement patterns and, in particular, to identify the occupation state of the table. The identification can be performed during a resting period of the electric drive motors of the table 1 but also during a correction movement of the drive motors. In the latter case the movement pattern typical for the occupation state is obtained by a superimposition of different movements comprising the adjustment movement by the operation of the drive motors and additionally the movement pattern of the table plate caused by the person occupying the table.

[0077] For each table 1 an occupation signal 12 is generated from a comparison of the sensed movement pattern with the reference movement pattern. For each table which is not occupied, the occupation signal 12 may have the value 0 and for each occupied table the occupation signal may have the value 1.

[0078] The occupation signals 12 are all transmitted to a central location 9. They are transmitted either by wireless transmission or via data or, respectively, communication lines. The occupation signals 12 are evaluated in the central location 9 for example so as to determine a balance between actually non-occupied tables 1 and a need for non-occupied tables. This facilitates to assign tables to persons who are looking for an unoccupied table.

[0079] The central location 9 controls a display unit 10 on which the non-occupied tables 1 are optically indicated so that persons seeking a non-occupied table can easily find one. Additionally or alternatively, technical devices 11 may be provided, for example lighting devices, which are activated depending on the occupation state of the table to switch the lights on for occupied tables or heating or cooling devices for heating or cooling the surroundings of occupied tables.

[0080] FIG. 5 shows a controller 13 for an electrical drive motor with a housing 14 for accommodating a circuit board of the controller. The housing 14 of the controller 13 consists in particular of a plastic material which may be glass-fiber reinforced. As plastic material for example PA 66 or a polycarbonate may be used. The housing 14 may have a wall thickness of for example at least 2 mm, to provide for high stability. At the inside wall of the housing 14 there may be longitudinal grooves 17 (FIG. 6) into which the circuit board of the controller is inserted.

[0081] In the area of a front side of the housing 14 there is an operating unit 15 with operating buttons 16 for switching the electric drive motors on and off. The operating unit 15 covers the front side of the housing 14 so that the interior of the housing is hermetically closed. The operating unit 15 may also consist of a plastic material. With the integration of the operating unit 15 into the housing 14 of the controller, a compact space-saving arrangement is obtained. In an embodiment of the furniture piece in the form of a height-adjustable table, the controller 13 is arranged for example below the table adjacent the front edge thereof. Because of the high stability of the housing 14 it can be subjected to relatively high forces without the danger of being destroyed.

[0082] Since there is no galvanic separation between the power supply net and the drive motor or, respectively, the controller 13, the operating unit 15 with the operating buttons 16 is arranged in the interior of the housing 14 with a sufficient distance of for example 6 mm from the circuit board. The distance may be bridged for example by extensions of the buttons 16 via which the switches on the circuit board can be operated. Alternatively, the signals may be transmitted to the circuit board contact-free for example by the use of light sources and photo transistors disposed on the circuit board and respectively on the operating unit or by the use of a radio module for the signal transmission.