GAS SPRING DEVICE FOR ADJUSTING THE HEIGHT OF AN OFFICE CHAIR

Abstract

A gas spring device of an office chair has a gas spring for height adjustment by means of a movable component and at least one sensor element, which is configured to detect a load and to generate a sensor signal depending on the detected load. In addition, the gas spring device has an electronic circuit adapted to generate user data depending on the at least one sensor signal. The user data represents one or more facts about the usage of the office chair. The at least one sensor element has at least one position sensor which is configured to detect a position of the movable component and to generate a position signal depending on the detected position.

Claims

1. A gas spring device for adjusting the height of an office chair, the gas spring device comprising a gas spring, arranged and equipped for height adjustment of the office chair by means of a movable component of the gas spring, at least one sensor element arranged on the gas spring device, configured to detect a load on the gas spring device and to generate at least one sensor signal depending on the detected load, and an electronic circuit arranged to generate usage data depending on the at least one sensor signal, the usage data representing one or more facts about a usage of the office chair; wherein the at least one sensor element comprises at least one position sensor which is adapted to detect a position of the movable component and to generate a position signal dependent on the detected position.

2. The gas spring device according to claim 1, further comprising a spring body arranged between a part of the movable component and a force sensor enclosed by the position sensor, wherein the force sensor is configured to detect a force acting from the spring body on the force sensor in the direction of a longitudinal axis of the gas spring and to generate a force signal depending on the detected force, and the circuit is configured to generate the position signal depending on the force signal.

3. The gas spring device according to claim 2, wherein the force sensor comprises a deformation body on which the spring body is supported, and wherein at least one deformation sensor is attached to the deformation body and is adapted to generate the force signal as a function of a detected deformation of the deformation body.

4. The gas spring device according to claim 2, wherein the spring body comprises a spiral spring.

5. The gas spring device according to claim 1, wherein the circuit is adapted to generate height data representing a height adjustment of the office chair as a function of the position signal.

6. The gas spring device according to claim 1, wherein the circuit is configured, to determine, based on a change in the position signal and on a spring constant of the gas spring, a force which acts on the gas spring in the direction of a longitudinal axis of the gas spring, and to generate second additional weight data representing the body weight of a user of the office chair, depending on the determined force.

7. The gas spring device according to claim 1, wherein the position sensor comprises at least one combination of at least one conductive surface and an associated slider formed between a fixed part of the gas spring device and the movable component.

8. The gas spring device according to claim 7, wherein the combination comprises at least one potentiometer with a resistive surface as the conductive surface and with the associated slider, and wherein the circuit is configured to generate the position signal depending on a resistance of the at least one potentiometer.

9. The gas spring device according to claim 8, wherein the at least one potentiometer is formed parallel to a longitudinal axis of the gas spring and is disposed between an inside of a housing of the gas spring device and the movable component, and wherein the position signal comprises an axial position.

10. The gas spring device according to claim 8, wherein the at least one potentiometer is designed as an angular potentiometer which is formed circularly to a longitudinal axis of the gas spring with a circular or circular segment shaped resistive surface and with the associated slider, wherein either said resistive surface or the associated slider is arranged rotationally fixed with respect to a housing of the gas spring device, and wherein the position signal comprises a radial position.

11. The gas spring device according to claim 10, wherein the rotationally fixed part of the angular potentiometer is not displaceable with respect to the longitudinal axis in the housing.

12. The gas spring device according to claim 10, wherein the rotationally fixed part of the angular potentiometer is displaceable with respect to the longitudinal axis in the housing.

13. The gas spring device according to claim 12, wherein the position sensor comprises a further combination of a further conductive surface and an associated slider, and wherein the further combination is configured to transmit the position signal.

14. The gas spring device according to claim 10, wherein the position sensor comprises an element, in particular a tube, for transferring a rotational movement of the gas spring to either the resistive surface of the angular potentiometer or the associated slider.

15. The gas spring device according to claim 7, wherein the combination comprises at least one path having at least one conductive surface and at least one non-conductive surface for binary coding, wherein a slider is associated with each path, and wherein the circuit is arranged to generate the position signal in dependence on a conductivity between the at least one path and the associated slider.

16. The gas spring device according to claim 15, wherein the at least one path is arranged parallel to a longitudinal axis of the gas spring, and wherein the position signal comprises an axial position.

17. The gas spring device according to claim 15, wherein the at least one path is circular to a longitudinal axis of the gas spring having a circular or circular segment shape, wherein either the at least one path or the associated slider is arranged rotationally fixed with respect to a housing of the gas spring device, and wherein the position signal comprises a radial position.

18. The gas spring device according to claim 1, wherein the movable component comprises a piston and a cylinder longitudinally displaceable therein, which are rotationally coupled to each other, wherein the position sensor comprises an angle sensor which detects an angular position of the cylinder, and wherein the position signal comprises a radial position.

19. The gas spring device according to claim 18, wherein the angle sensor comprises a coding disc or a magnet with at least one Hall sensor, in particular at least two Hall sensors.

20. The gas spring device according to claim 1, wherein the movable component comprises a piston and a cylinder longitudinally displaceable therein, an end face of the cylinder forms a reflector surface, the reflector surface has a defined varying extent over a circumference of the cylinder in the direction of a longitudinal axis of the gas spring with respect to a normal to the longitudinal axis, the position sensor comprises a first and an at least second distance sensor fixedly mounted in a housing of the gas spring device and configured to detect a first and second distance to the reflector surface, and the circuit is configured to generate the position signal as a function of the first and second distances.

21. The gas spring device according to claim 20, wherein the defined varying extent is based on a sine curve.

22. The gas spring device according to claim 20, wherein the circuit is configured to generate the position signal with an axial position, based on a sum of the first and second distances, and/or with a radial position, based on a difference of the first and second distances.

23. The gas spring device according to claim 1, wherein the position sensor is configured to determine a resonance frequency of a vacant space in a housing of the gas spring device to the movable component, wherein the circuit is configured to generate the position signal as a function of the determined resonance frequency, and wherein the position signal comprises an axial position.

24. The gas spring device according to claim 1, wherein the position sensor comprises a first conductive surface formed on an inside of a housing of the gas spring device and a second conductive surface formed on an outside of the movable component in the housing, wherein a capacitive arrangement is formed by the first and second conductive surfaces, wherein the circuit is configured to generate the position signal in dependence on a capacitance value of the capacitive arrangement, and wherein the position signal comprises an axial position.

25. The gas spring device according to claim 1, wherein the gas spring device comprises an energy harvesting device with at least one coil and at least one permanent magnet, which is arranged to harvest electrical energy from a movement of the movable component, the circuit is connected to the energy harvesting device to supply power to the circuit, the at least one coil or the at least one permanent magnet is attached to the movable component, the at least one sensor element comprises at least one further position sensor which is configured to detect a position of the movable component based on a spatial inhomogeneity of a magnetic flux density generated by the at least one permanent magnet and to generate a further position signal depending on the detected position, and the circuit is configured to generate further height data representing a height setting of the office chair depending on the further position signal.

26. The gas spring device according to claim 1, wherein the circuit comprises a communication interface configured for wireless transmission of the usage data to at least one external receiver.

27. The gas spring device according to claim 26, wherein the communication interface is adapted to transmit the usage data via Bluetooth, WLAN, Zigbee, RF, RFID or a GSM-based technology.

28. The gas spring device according to claim 26, wherein the external receiver is formed as a smartphone or tablet computer.

29. The gas spring device according to claim 1, further comprising a plug connector for a plug connection adapted to electrically connect the gas spring device to other electronic components of the office chair.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0109] In the following, the invention is explained in detail on the basis of exemplary implementation forms with reference to the drawings. Components that are functionally identical or have an identical effect can have identical reference signs. Identical components or components with identical functions may be explained only in terms of the figure in which they appear first. The explanation is not necessarily repeated in the following figures.

[0110] In the drawings:

[0111] FIG. 1 shows an office chair with a gas spring device;

[0112] FIGS. 2A and 2B show a cross-section of an exemplary design of a gas spring device according to the improved concept;

[0113] FIG. 3 shows another representation of an office chair with a gas spring device;

[0114] FIG. 4 shows a cross-section of another exemplary design of a gas spring device according to the improved concept;

[0115] FIG. 5 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0116] FIG. 6 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0117] FIG. 7 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0118] FIG. 8 is an example implementation of a position measurement for a gas spring device according to the improved concept;

[0119] FIG. 9 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0120] FIGS. 10A and 10B an example implementation of a position measurement for a gas spring device according to the improved concept;

[0121] FIG. 11 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0122] FIG. 12 shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0123] FIG. 13A shows a cross-section of another example implementation of a gas spring device according to the improved concept;

[0124] FIG. 13B is an example implementation of a permanent magnet arrangement for use in a gas spring device according to the improved concept;

[0125] FIG. 13C is another example implementation of a permanent magnet assembly for use in a gas spring device according to the improved concept; and

[0126] FIG. 14 is another example implementation of a permanent magnet arrangement for use in a gas spring device according to the improved concept.

DETAILED DESCRIPTION

[0127] FIG. 1 shows a work chair BS with a gas spring device, for example a gas spring device according to the improved concept. The work chair BS has a seat surface SF, a backrest RL connected to the seat surface SF and a base FK.

[0128] In addition, the work chair BS comprises a gas spring device, which includes a housing G and a gas spring with a piston K and a cylinder Z, for example. In the example in FIG. 1, the housing G of the gas spring device is connected to the base FK of the work chair BS via a cone (not shown). In addition, the piston K or the cylinder Z is connected to the seat surface SF of the work chair BS via a cone (not shown).

[0129] The gas spring, for example, is an adjustable gas spring that is designed to adjust the seat height of the work chair BS, especially the seat surface SF. Optionally, an inclination of the seat surface SF and/or the backrest RL.

[0130] FIG. 2A and FIG. 2B show an exemplary sectional view of a design of a gas spring device according to the improved concept. The gas spring device contains a housing G, which can be connected to the base FK of the work chair BS in the area of a cone KON. Furthermore, the gas spring device comprises a gas spring with a cylinder Z and a piston K. The piston K can also be called a piston rod. In the example shown, for example, the piston K is permanently connected to the housing G via an axial bearing AL. The cylinder Z is mounted or fastened in the housing G by means of a BM fastener. This BM fastener acts as a guide element for cylinder Z in housing G.

[0131] In FIG. 2B the area of the gas spring device around the end plate EP is shown enlarged in an exploded view. It becomes clearer that the thrust bearing AL is designed as a ball bearing. A circuit SK is arranged in an electronic housing EG. Circuit SK, for example, can contain a circuit board or printed circuit board on which electronic components and/or integrated circuits are arranged and, if necessary, interconnected.

[0132] FIG. 3 shows another representation of an office chair BS with the gas spring device, which is based on the representation of FIG. 1. Various positions are shown at which a force measurement can be carried out, for example. One of these points is, for example, the connection point CP between the chair and the gas spring device. It is also possible to measure the force at the connection point BP between the gas spring device and the base FK. Alternatively or additionally, a force measurement can also be carried out within the gas spring device, marked by the point IP.

[0133] FIG. 4 shows a cross-section of an exemplary design of a gas spring device according to the improved concept, especially for use in an office chair BS, as shown in FIG. 1 or FIG. 3.

[0134] The gas spring device comprises a housing G, which, for example, is connected via a first cone to the base FK of the work chair BS. In addition, the gas spring device comprises a gas spring with a cylinder Z and a piston K. In the example shown, for example, the piston K is fixedly connected to the housing G. The cylinder Z, for example, is connected to the seat surface SF of the work chair BS via a second cone. With fixed housing G and piston K, cylinder Z can move along a longitudinal axis of the gas spring, for example to adjust the height of the seat surface SF and/or to cushion the seat surface SF, for example when a user sits down on the work chair BS. The longitudinal axis of the gas spring is indicated by a semi-dotted line in FIG. 4. In addition to the movement along the longitudinal axis, the gas spring, in particular the cylinder and/or piston K, can be rotationally movable to allow the seat surface SF of the work chair BS to rotate.

[0135] The gas spring has, for example, an adjustment element V on cylinder Z. If the adjustment element V is actuated, for example by a lever (not shown) which can be actuated by the user of the office chair, a movement of the cylinder Z along the longitudinal axis of the gas spring is released for height adjustment of the seat surface SF. If the adjustment element V is not actuated, the cylinder is locked, so that a height adjustment of the seat surface SF is not possible. In this state, for example, the gas spring is only used for damping depending on a spring constant of the gas spring.

[0136] The gas spring device also has a fastener BM, which is firmly connected to the cylinder Z, for example. For example, the fastener BM can be ring-shaped and enclose the cylinder Z. Alternatively, the fastener BM can also have two or more elongated or rod-shaped individual components which are attached to the cylinder Z at different, in particular opposite-positions. If the cylinder Z moves along the longitudinal axis or if the cylinder Z rotates around the longitudinal axis of the gas spring, the fastener BM also moves along the longitudinal axis or rotates around the longitudinal axis accordingly.

[0137] The gas spring device also has an electronic circuit SK. The circuit SK, for example, can be located on or attached to the fastener BM, in particular. Circuit SK, for example, can contain a circuit board or printed circuit board on which electronic components and/or integrated circuits are arranged and, if necessary, interconnected. For example, the board can be attached to the fastener BM.

[0138] The gas spring device also has a force sensor KS, which is attached, for example, to the gas spring, especially to the piston K or to the housing G. In the example shown, the force sensor KS is attached to piston K. The force sensor KS, for example, can include a strain gauge that is attached to the piston K, for example. Alternatively, the force sensor KS can include a piezoelectric sensor, which is arranged, for example, on the piston K or between the piston K and the housing G. The force sensor KS is electrically connected to the circuit SK (connection not shown).

[0139] When a force acts on the gas spring in the direction of the longitudinal axis of the gas spring, for example because a user sits on the work chair BS, the force sensor KS detects the force acting in the direction of the longitudinal axis and generates a force signal depending on the force detected. The force sensor KS transmits the force signal to the circuit SK. For example, the circuit SK calculates weight data representing the body weight of the user of the work chair BS from the force signal.

[0140] The circuit SK also includes a communication interface, in particular an interface for wireless data transmission. The interface can be a Bluetooth interface, a WLAN interface, a GSM-based interface, a radio interface such as Zigbee, RF or RFID or another interface. For example, the circuit can transmit the weight data via the communication interface to an external receiver, such as another office equipment, a display device such as a smartphone or tablet computer, a computer or a server.

[0141] Optionally, the gas spring device has a deformation sensor, which in the example shown in FIG. 4 comprises a first deformation sensor element VS1 and a second deformation sensor element VS2. The deformation sensor elements VS1, VS2 are arranged on the cylinder Z, for example. The deformation sensor elements VS1, VS2 are strain gauges, for example. The deformation sensor elements VS1, VS2 are electrically connected to the circuit SK.

[0142] If the gas spring, in particular cylinder Z, is deformed, for example by a position of a center of gravity of the user of the work chair BS or a change in the position of the center of gravity, the deformation sensor elements VS1, VS2 detect a deformation of the gas spring, in particular of cylinder Z, for example by a different load on cylinder Z at the positions of the deformation sensor elements VS1, VS2. The deformation sensor, in particular the deformation sensor elements VS1, VS2, are designed to generate a deformation signal depending on the detected deformation and to transmit the deformation signal to the circuit SK. Depending on the deformation signal, especially depending on the deformation signal and the force signal, the circuit determines center of gravity data representing a position or a position of the center of gravity of the user of the office chair.

[0143] For example, the circuit SK is set up to transmit the center of gravity data to the external receiver via the communication interface.

[0144] In some embodiments, the circuit is set up to generate the center of gravity data depending on the deformation signal and the force signal.

[0145] FIG. 5 shows an embodiment of a gas spring device which is designed for position measurement by means of mechanical integration. For this purpose, the gas spring device has a spiral spring SP inside the housing, which is arranged between a cam MF, which is attached to the cylinder Z, and a deformation body VK. For example, a deformation sensor is arranged as a force sensor on the deformation body VK and forms a measuring point DMP. The spiral spring SP is supported on the deformation body VK, so to say.

[0146] When the axial position of the cylinder is changed, the spiral spring SP is compressed or released. The axial position can be calculated by measuring the current load using the constant spring rate of the spiral spring SP. Other spring bodies can also be used instead of the spiral spring SP.

[0147] FIG. 6 shows another embodiment of a gas spring device for position measurement. In the example implementation shown, the position measurement is carried out by means of resistive measurements based on the principle of a potentiometer.

[0148] For example, an axial resistance path APCB is mounted on the inside of the housing, which extends essentially parallel to the longitudinal axis of the gas spring. An axial grinder ASC is provided, which is secured against rotation and attached to the axially displaceable cylinder. Shifting the slider ASC along the resistance path APCB results in a changing resistance from which the axial position can be determined.

[0149] The illustration also shows a radial resistance path RPCB with an associated radial grinder RSC. The grinder RSC is coupled to a driving tube TRR to transfer a rotary movement of the gas spring to the grinder RSC. The radial resistance path RPCB extends circularly or at least in the form of a circular segment around the longitudinal axis of the gas spring or piston K. The resulting resistance value from the combination of the radial resistance path RPCB and the radial grinder RSC can in turn be used to indicate a position, in this case an angular position.

[0150] The measured resistance values are processed, for example, in the circuit SK not shown here.

[0151] Although both axial position measurement and radial position measurement are shown in FIG. 6, it is of course possible to implement only one of the two measurements in different implementation forms.

[0152] In the design shown, a plate with the radial resistance paths RPCB is fixedly connected to the housing and in particular cannot be displaced in relation to the longitudinal axis in the housing.

[0153] FIG. 7 shows a further embodiment of a position sensor in a gas spring device based on the principle of a potentiometer, in which the radial resistance path RPCB is attached to the gas spring via an adapter GAD and can thus be displaced in relation to the longitudinal axis in the housing. In addition, the same measuring principle is used as described in FIG. 6. The axial measurement is not shown for overview purposes only, but can also be used here.

[0154] To transmit the signals from the moving part with the adapter GAD to the outside, i.e. to the inside of the housing, a conductive path SPCB is provided in the version shown, to which a non-rotatably arranged slider SSC belongs for signal transmission. In particular, the combination of conductive track SPCB and associated slider SSC is mounted on both sides in the embodiment shown. The conductive track SPCB also acts as an anti-rotation device for the adapter GAD.

[0155] The resistance paths can be printed circuit boards or PCBs, for example. This also applies to the path for signal transmission SPCB.

[0156] FIG. 8 shows another embodiment of a position sensor in which coded paths are provided instead of resistance paths, for example on a printed circuit board.

[0157] In the exemplary representation of FIG. 8, a first path BX is used for power supply, while paths B0, B1 and B2 are used for position coding. For this purpose, the respective paths B0, B1, B2 are divided into corresponding conductive and non-conductive areas according to a binary coding. A coding slider CSC moves when the gas spring device moves and contacts the individual paths B0, B1, B2 depending on the position, so that a position can be determined in a resolution corresponding to the number of paths. So in the example at hand with three tracks a resolution of 2{circumflex over ()}3=8 positions results. This can be changed in a known way by adding further paths or by omitting paths.

[0158] The principle can be used for axial position measurement, whereby in principle reference is made to FIG. 6. However, the principle can also be used for radial position measurements, in which case the paths must again be arranged in a circle around the longitudinal axis or the piston. The mechanical requirements again result from the basic description of FIGS. 6 and 7.

[0159] FIG. 9 shows another embodiment of a gas spring device. In the version shown, the cylinder and the piston are connected to each other non-rotatably via a cam MF2 and an anti-rotation tube RVS.

[0160] This enables the measurement of a radial position at piston K. Such a measurement can be carried out, for example, via an arrangement with a magnet and one or more Hall sensors. Furthermore, it is possible to use a coded disk (not shown), which is arranged in connection with the piston K, for the measurement.

[0161] FIGS. 10A and 10B show an embodiment of a position measurement on the gas spring device based on a distance measurement. For this purpose, one end face of cylinder Z is designed as a reflector surface RFF. The reflector surface RFF has a defined varying extension over a circumference of cylinder Z in the direction of a longitudinal axis of the gas spring with respect to a normal extension to the longitudinal axis. While FIG. 10A shows a three-dimensional representation of the arrangement, FIG. 10B shows a lateral surface MAF of cylinder Z in the plane, i.e. unwound. For example, it can be seen that the reflector surface RFF extends essentially based on a sine curve.

[0162] The arrangement also has a first and a second distance sensor OS1, OS2, which measure a distance W1 or W2 to the reflector surface RFF. From the distances W1, W2 unique conclusions can be drawn about the position or location of the arrangement. For example, a unique angular position can be calculated by a difference of the two distances W1, W2. The axial position can be determined by averaging, or generally a sum of the distances W1, W2.

[0163] The distance sensors OS1, 0S2 can be designed as optical sensors based on infrared or laser radiation or as ultrasonic sensors.

[0164] FIG. 11 shows another type of gas spring device with a position sensor. In the design shown, conductive surfaces TA are attached to an inner side of the housing G as first, outer electrodes. Analogous to this, further conductive surfaces KA are provided on an outside of cylinder Z, which form second, inner electrodes. The first and second conductive surfaces TA, KA can also be formed directly through the inside of the housing G or the outside of the gas spring or the cylinder Z itself. Separate guide surfaces are therefore not absolutely necessary.

[0165] However, the surfaces TA, KA mentioned are not conductively connected to each other but are designed in such a way that they form a capacitive arrangement. When the cylinder moves in housing G, the overlapping surface between the electrodes TA, KA changes, resulting in a changed capacitance value. This can be evaluated, for example, by the electronics in the circuit SK, which it is not shown for overview reasons.

[0166] The linear reference allows direct conclusions to be drawn about the axial position from the determined capacity values.

[0167] FIG. 12 shows another potential embodiment of the gas spring device, which is essentially based on the embodiment shown in FIG. 4.

[0168] The gas spring device in this embodiment optionally contains an energy harvesting device with an energy store (not shown), a coil S1 and a permanent magnet arrangement M. The energy store can be contained by the circuit SK or be arranged at another location of the gas spring device, for example in the housing G.

[0169] In the example in FIG. 12, coil S1 is arranged in a ring around the cylinder Z. So one or more windings of coil S1 run ring-shaped or essentially ring-shaped around cylinder Z. For example, the coil S1 is wound or arranged around the fastener BM. For example, a winding axis of coil S1 is parallel to or coincides with the longitudinal axis of the gas spring. Coil S1 is electrically connected to circuit SK.

[0170] The permanent magnet arrangement M in the gas spring device of FIG. 12, for example, is formed by an annular permanent magnet or a large number of annular permanent magnets RM1, RM2, RM3, RM4, RM5. It should be noted that the permanent magnet arrangement M comprises at least one annular permanent magnet. In particular, the number of ring-shaped permanent magnets is not necessarily equal to 5, as shown in FIG. 12. In addition, the permanent magnet arrangement M can also contain more than five annular permanent magnets, as indicated by the points in FIG. 12.

[0171] Each of the annular permanent magnets RM1, RM2, RM3, RM4, RM5 is radially magnetized. In particular, each of the annular permanent magnets RM1, RM2, RM3, RM4, RM5 has a north pole on an inner side, in particular a radial inner side, and a south pole on an outer side, in particular a radial outer side, or vice versa. The North and South poles are shown in FIG. 12 as N and S. The annular permanent magnets RM1, RM2, RM3, RM4, RM5 of the permanent magnet arrangement M, for example, are stacked one above the other along the longitudinal axis of the gas spring. Neighboring annular permanent magnets are magnetized in the opposite direction. For example, annular permanent magnets adjacent to an annular permanent magnet with a south pole on the inside and a north pole on the outside have a north pole on the inside and a south pole on the outside and vice versa.

[0172] Each of the annular permanent magnets RM1, RM2, RM3, RM4, RM5 has a symmetry axis which coincides with or substantially coincides with the longitudinal axis of the gas spring or runs parallel to the longitudinal axis of the gas spring. The annular permanent magnets RM1, RM2, RM3, RM4, RM5 are arranged around the cylinder Z, the fastening element BM and the coil S1. The annular permanent magnets RM1, RM2, RM3, RM4, RM5, for example, are mounted on an inner side of housing G.

[0173] The permanent magnet arrangement M generates an inhomogeneous magnetic flux density inside the annular permanent magnets RM1, RM2, RM3, RM4, RM5. The arrangement and orientation of the annular permanent magnets RM1, RM2, RM3, RM4, RM5 or their axis of symmetry and the arrangement or orientation of coil S1 generate a magnetic flux through coil S1. Due to the inhomogeneity of the magnetic flux density, the magnetic flux through coil S1 changes during movement of cylinder Z and thus of coil S1 along the longitudinal axis of the gas spring.

[0174] The changing magnetic flux through coil S1 induces a voltage in coil S1 by electromagnetic induction and generates a current in the coil based on the induced voltage, for example. The circuit SK is designed to tap the induced voltage and/or the generated current and thus charge the energy store. If necessary, the circuit SK may also be equipped to rectify the induced voltage or the current generated to charge the energy store by means of a rectifier circuit.

[0175] A power supply of the circuit SK, the force sensor KS, the deformation sensor, the communication interface and/or other elements of the gas spring device is thus possible by means of the energy harvesting device and the energy store.

[0176] In alternative embodiments, the energy harvesting device can contain the force sensor KS instead of or in addition to the coil S1 and the permanent magnet arrangement M, especially if the force sensor KS comprises a piezoelectric sensor. The energy store can then be charged, for example, by an electrical voltage generated by the piezoelectric sensor or a resulting current.

[0177] It should be noted that alternative embodiments of the gas spring device do not include the energy harvesting device. In such designs, for example, the circuit can be supplied with electrical energy via one or more batteries.

[0178] Alternative embodiments of the gas spring device do not include the force sensor KS and/or the deformation sensor.

[0179] In alternative embodiments, the housing G is not connected to the base FK, but to the seat surface SF, for example, while the piston K or the cylinder Z is connected to the base FK.

[0180] In alternative embodiments, not the cylinder Z of the gas spring is movable, but the piston K, while the cylinder Z is fixedly connected to the housing G along the longitudinal axis of the gas spring.

[0181] In alternative embodiments, the circuit SK is not arranged on the fastener BM, but for example at a different position in or on the housing G. Circuit SK for example can also be arranged outside of housing G.

[0182] In alternative embodiments, the permanent magnet arrangement M is connected to the cylinder Z and is moved along the longitudinal axis when the cylinder Z moves. In such designs, the coil S1 is not connected to the cylinder Z and is not moved along the longitudinal axis when the cylinder Z moves.

[0183] Optionally, the gas spring device has a plug connector ST, especially a plug or a socket. The connector ST, for example, can be connected to another corresponding connector of the office chair BS, which is arranged, for example, on the seat surface SF or the base FK. In addition, the connector ST is electrically connected to the circuit SK.

[0184] Via the connector, for example, data can be exchanged between the circuit SK and other electronic components of the office chair BS. In particular, data can be transferred from the other electronic components of the office chair to the circuit SK. The data transmitted from the other electronic components to the circuit SK, for example, can be transmitted via the communication interface of the circuit SK to the other external receiver.

[0185] The other electronic components can, for example, be supplied with electrical energy via the energy harvesting device and the plug connector ST. In designs that include both the connector ST and the energy harvesting device, the energy harvesting device can be used to supply power to the other electronic components.

[0186] FIG. 13A shows another example embodiment of a gas spring device according to the improved concept. The gas spring device of FIG. 13A is based on the gas spring device of FIG. 4 or FIG. 12.

[0187] Differences between the gas spring device of FIG. 13A and the gas spring device of FIG. 4 or FIG. 12 concern, for example, only the energy harvesting device and possibly a shape of the fastener BM.

[0188] The energy harvesting device of the gas spring device of FIG. 13A contains a coil S2 whose windings run, for example, around a winding axis which lies in a plane which is perpendicular to the longitudinal axis of the gas spring. For this purpose, for example, the coil S2 can be arranged on the fastener BM. The fastener comprises, for example, at least one elongated component arranged on the cylinder L.

[0189] In the gas spring device of FIG. 13A, the permanent magnet arrangement M contains a first and a second permanent magnet M1, M2. The first permanent magnet M1, for example, is mounted on a first side of housing G, especially on an inner side of housing G. For example, the second permanent magnet M2 is mounted on a second side of housing G, especially on an inner side of housing G. The second side is opposite the first side. The first permanent magnet M1 has a south pole on one side facing housing G and the second permanent magnet M2 has a north pole on one side facing housing G. The first permanent magnet M1 has a north pole. Accordingly, the first permanent magnet M1 has a north pole on one side facing away from the housing G, i.e. towards the gas spring, while the second permanent magnet M2 has a south pole on one side facing away from the housing, i.e. towards the gas spring.

[0190] The arrangement of coil S2 or its orientation and the arrangement and orientation of the first and second permanent magnets M1, M2 generate a magnetic flux density which, depending on the position, especially the rotational position, generates a more or less large magnetic flux through coil S2. If the cylinder Z or the gas spring rotates around the longitudinal axis of the gas spring, for example caused by a rotation of the office chair or the seat surface SF, the coil S2 also rotates in this way. Consequently, an angle that includes the coil S2, in particular a winding plane or the winding axis of the coil S2, with a direction of magnetic flux density changes during rotation. As a result, the magnetic flux through coil S2 varies during the rotational movement around the longitudinal axis, which in turn leads to an induction voltage in coil S2. The induced voltage induces a current which is picked up by the circuit SK, rectified if necessary and used to charge the energy store.

[0191] With a gas spring device as in FIG. 13A, electrical energy can be harvested from a rotational movement of the seat surface and thus the energy store can be charged. It is pointed out that in other embodiments the energy harvesting devices of the gas spring devices as described and shown in FIGS. 12 and 13A, 13B and 13C can be combined at any time. This means that energy can be won and stored in the energy store both when the seat surface or gas spring rotates and when it moves along the longitudinal axis of the gas spring.

[0192] FIG. 13B shows an example implementation of a permanent magnet arrangement M for use in a gas spring device according to the improved concept, in particular a gas spring device as shown in FIG. 13A.

[0193] For example, the first magnet M1 is a semicircular magnet with radial magnetization, so that on the inside of the first magnet M1 there is a north pole and on the outside of the first magnet M2 there is a south pole. Correspondingly, the second permanent magnet M2 is also designed as a radially magnetized semicircular magnet. The second permanent magnet M2 has a south pole on one inside and a north pole on one outside. The first and second permanent magnets M1, M2 are arranged so that together they form a ring which is arranged around the coil S2 and the gas spring, as shown in FIG. 13A.

[0194] Just for clarification, a single winding of coil S2 and an exemplary direction of the magnetic flux density B are shown.

[0195] In alternative embodiments, the permanent magnet arrangement M can also be designed as a single diametrically polarized magnet. With such magnets, one half ring half represents a north pole and another half ring half a south pole.

[0196] FIG. 13C shows another example of a permanent magnet arrangement M for use in a gas spring device according to the improved concept, in particular a gas spring device as shown in FIG. 13A.

[0197] The permanent magnet arrangement M is annular (FIG. 13C shows only a partial segment of the permanent magnet arrangement M) and runs around the coil S2 and the gas spring, especially the cylinder Z. The permanent magnet arrangement M consists of permanent magnets M3, M4, M5, M6 arranged side by side, which for example have the form of ring segments. Adjacent ring segments correspond to alternately magnetized magnets, especially alternately radially magnetized magnets. Each ring segment M3, M4, M5, M6 has either a north pole on one side and a south pole on the outside or vice versa. Ring segments adjacent to a ring segment which has a south pole on the inside and a north pole on the outside have a north pole on the inside and a south pole on the outside and vice versa.

[0198] The magnetic flux density B runs in an arc on the inside of the permanent magnet arrangement M from the north poles of the ring segments to the south poles of the adjacent ring segments. This generates an inhomogeneous magnetic field inside the permanent magnet arrangement M. Consequently, the magnetic flux through coil S2 changes during a rotational movement of coil S2 around the longitudinal axis of the gas spring, which in turn leads to an induced voltage in coil S2. For the sake of clarity, the magnetic flux density B is shown as an example only between two ring segments M5, M5.

[0199] FIG. 14 shows another example implementation of a permanent magnet arrangement M for use in a gas spring device according to the improved concept. The permanent magnet arrangement M of FIG. 14, for example, can be used in a gas spring device as in FIG. 12 instead of or in addition to the permanent magnet arrangement shown and described there.

[0200] The permanent magnet arrangement M of FIG. 14 contains an annular permanent magnet RM, which is arranged around the gas spring, especially around the cylinder Z. The longitudinal axis of the gas spring is indicated in FIG. 14 by a semi-dot line. The permanent magnet arrangement M also has a first ferromagnetic element FM1, which has a U-shaped profile with an opening facing away from the gas spring or cylinder Z, respectively. The first ferromagnetic element FM1, for example, is rotationally symmetrical around the longitudinal axis of the gas spring and runs around the gas spring or around the cylinder Z. The annular permanent magnet RM is radially magnetized and has a south pole on a radial inner side and a north pole on a radial outer side or vice versa. The annular permanent magnet RM1 is connected to the first ferromagnetic element FM1, in particular magnetically conductive. For example, the annular permanent magnet RM1 is located inside the U-shaped profile of the first ferromagnetic element FM1.

[0201] The permanent magnet arrangement M also has a coil S3, which is arranged around the annular permanent magnet RM and is connected to it, for example. A winding axis of the coil S3 is parallel to the longitudinal axis of the gas spring and/or to the symmetry axis of the annular permanent magnet RM.

[0202] For example, the first ferromagnetic element FM1 is connected to the cylinder Z of the gas spring, so that when the cylinder Z moves along the longitudinal axis of the gas spring, the first ferromagnetic element FM1, the annular permanent magnet RM and the coil S3 also move along the longitudinal axis of the gas spring.

[0203] The permanent magnet arrangement M also has a second ferromagnetic element FM2, which is not moved along the longitudinal axis of the gas spring when the cylinder Z moves and is connected, for example, to the housing G of the gas spring device. The second ferromagnetic element FM2, for example, is arranged rotationally symmetrically around the gas spring, for example on an inner side of housing G. The second ferromagnetic element FM2 has a stepped profile. In particular, the second ferromagnetic element FM2 has first regions which have a first distance, in particular a first radial distance, from an axis of symmetry of the second ferromagnetic element FM2 and second regions which have a second distance, in particular a second radial distance, from the axis of symmetry of the second ferromagnetic element FM2. The second distance is greater than the first distance.

[0204] When the cylinder Z, the first ferromagnetic element FM1, the annular magnet RM and the coil S3 move along the longitudinal axis of the gas spring, the magnetic flux density at one position of the coil S3 varies through a changing flux density guidance due to the first and second ferromagnetic elements FM1, FM2, the U-shaped profile of the first ferromagnetic element FM1 and the stepped profile of the second ferromagnetic element FM2.

[0205] This causes a magnetic flux through the coil S3 to change during movement along the longitudinal axis, resulting in an electromagnetically induced voltage in the coil S3.

[0206] For example, the first and/or second ferromagnetic elements FM1, FM2 contain iron or another ferromagnetic material.

[0207] In alternative embodiments, the second ferromagnetic element FM2 is connected to the cylinder Z and is moved along the longitudinal axis. Then the first ferromagnetic element FM1, the annular permanent magnet RM and the coil S3 are not connected to the cylinder Z and are therefore not moved along the longitudinal axis.

[0208] The different aspects and components of the gas spring device or the office chair BS according to the improved concept described here can be combined depending on the specific application.

[0209] With an office chair BS according to the improved concept, it is possible to record user data such as the weight data, the center of gravity data, the other weight data, the height data and/or the other height data and to transmit them to an external receiver, for example to evaluate the user data, using the circuit SK. The evaluated user data can serve, for example, as a basis for instructions to the user of the office chair BS. In this way, the usage behavior of the user of the BS office chair can be improved.

[0210] By arranging the at least one sensor element, the circuit SK and, if necessary, the energy harvesting device in or on the gas spring device, a particularly efficient and flexible solution is achieved. In particular, the gas spring device is easy to replace, so that, for example, conventional office chairs can also be equipped with a gas spring device of an office chair BS according to the improved concept.

REFERENCE SIGNS

[0211] BS office chair [0212] SF seat surface [0213] RL backrest [0214] FK base [0215] G housing [0216] Z cylinder [0217] K piston [0218] SK electronic circuit [0219] KON cone [0220] KS force sensor [0221] VS1, VS2 deformation sensor elements [0222] BM fastener [0223] V adjustment element [0224] ST connectors [0225] S1, S2, S3 coils [0226] M permanent magnet arrangement [0227] RM1, RM2, RM3, permanent magnets [0228] RM4, RM5, RM, M1, permanent magnets [0229] M2, M3, M4, M5, M6 permanent magnets [0230] S South pole [0231] N North pole [0232] B magnetic flux density [0233] FM1, FM2 ferromagnetic elements [0234] SSC, RSC, ASC grinders [0235] SPCB, RPCB, APCB path [0236] GAD adapter [0237] OS1, OS2 distance sensor [0238] EG electronic housing [0239] AL thrust bearing [0240] MF, MF2 cam