Collision detection device for adjustable furniture

Abstract

The invention relates to a collision detection device (2) configured to be arranged in an adjustable furniture item comprising drive means (11) and a first part (14) and a second part (16) movable relative to each other. A collision detection device is configured to detect a collision during movement of the adjustable furniture item. The collision detection device (2) comprises a holder (38) configured, in use, to be arranged on one of the first and second parts (14, 16) of the adjustable furniture item to at least indirectly contact with a portion of the drive means (11), and a circuit board (31) arranged on the holder (38), said circuit board (31) comprising a wiring circuit (40) on at least one side thereof. The holder (38) is configured to transmit a force from the drive device (11) acting on the holder (38) to the circuit board (31) when arranged on the adjustable furniture item, such that said force means a deflection of the circuit board (31). The electrical characteristic of the wiring circuit (40) is configured to depend on the deflection of the circuit board (31).

Description

Technical Field

[0001] The present invention relates to a device for detecting collisions in adjustable items of furniture. Background Art

[0002] Tables and other furniture items are known from the prior art which have parts which are movable relative to one another, for example by means of one or several telescopic columns. An adjustable tabletop enables alternating sitting or standing at the table and can be adjusted based on the preferences of the user, for example due to the height of the user or the chair. The telescopic column can comprise several telescopic tubes with different cross sections, wherein in the retracted state of the telescopic column the tube with the smaller cross section extends inside the tube with the larger cross section. The telescopic column can be driven by a drive device which comprises a spindle with an external thread, which spindle is driven by an electric motor so as to be moved radially inside and along an internally threaded hollow spindle of the drive device.

[0003] However, adjusting the height of the surface by extending and retracting the telescopic columns may be risky. If the movement of the surface continues after a collision between the surface and an obstacle, the collision may result in property damage and / or personal injury.

[0004] There are anti-collision devices in the prior art, such as small safety edges, which can be applied to predetermined areas of the movable surface and transmit a signal when pressure is applied to them, thereby stopping the movement of the drive device through a signal sent to the controller unit of the drive device. Their significant disadvantage is that the movement is stopped only when the obstacle comes into contact with the small safety edge.

[0005] To solve this problem, the prior art comprises piezoelectric diaphragms which detect changes in the deflection of the tube of the telescopic column (since a collision between the movable surface and an obstacle may imply a deflection of such a tube) or in the acceleration of a movable part of the telescopic column (since a collision may imply an acceleration of such a part).

[0006] However, a disadvantage of this solution is that the piezoelectric diaphragm may falsely signal a collision due to, for example, friction between the movable parts of the telescopic column, which means undesired acceleration or deflection of the tube of the telescopic column. Furthermore, the friction between the movable parts may change during the life of the telescopic column due to wear, resulting in unreliable detection. Furthermore, current solutions are not able to detect collisions in the case of low collision forces, which means that the collision detection device fails to detect critical collision situations.

[0007] Therefore, a solution is needed that detects collisions with greater reliability and speed and reduces the probability of false collision detections. Summary of the invention

[0008] The object of the inventive concept is to provide an improved solution that alleviates the above mentioned drawbacks of prior art solutions. Furthermore, the object is to detect collisions during the movement of an adjustable furniture item, in particular collisions between a movable surface of the furniture item, such as a tabletop, and obstacles.

[0009] According to a first aspect of the invention, there is provided a collision detection device configured to be arranged in an adjustable furniture item, the detection device being configured to detect collisions and / or loads on the furniture item during movement of the adjustable furniture item. The adjustable furniture item comprises a drive device and a first component and a second component movable relative to each other. The collision detection device is configured to detect collisions during movement of the adjustable furniture item. The collision device can detect collisions with a higher reliability than devices in the prior art. This is important from a safety point of view to avoid property damage. The collision detection device can detect collisions with any type of obstacle that resists the movement of the furniture item. The invention is able to meet regulations that prior art inventions may not be able to do. The obstacle may be a part of furniture, a body part or any other object. The collision between the movable surface and the obstacle during movement may mean a resistance against the driving force of the drive device. Such a force may cause a load on the collision detection device, which may detect the load. The collision detection device comprises a holder configured to be arranged in use at one of the first component and the second component of the adjustable furniture item to be in at least indirect contact with a part of the drive device. The collision detection device also includes a circuit board arranged on the holder, the circuit board including a wiring circuit on at least one side thereof.

[0010] Furthermore, the electrical characteristics of the wiring circuit are configured to depend on the flexure of the circuit board.

[0011] The holder can be in contact with the drive and the circuit board in such a way that the force from the drive can be transmitted to the circuit board. The contact force between the holder and the resistance from the drive can mean a bending moment on a part of the furniture item or the drive, which acts on the circuit board via the holder, thus meaning a deflection of said circuit board.

[0012] The holder may be a solid unit made of, for example, plastic or metal. The holder may be formed and shaped to fixedly hold the circuit board. The circuit board may be arranged on the holder in a fixed manner so that any movement of the holder is transmitted to the circuit board. Arranging the holder in one of the first and second parts of the adjustable furniture item may mean that the holder is a separate component, which is arranged in one of the first and second parts by means of fastening means (such as screws) or form fit (such as a snap fit function). Alternatively, it may mean that the holder is formed as an integral part of one of the first and second parts to which the holder is arranged. In such an embodiment, the holder may be a part of the first or second part that is configured to hold the circuit board and is at least indirectly in contact with a part of the drive device.

[0013] The circuit board may include a substrate on which the at least one wiring circuit may be arranged. The circuit board may further include at least two connection terminals for connecting the end of the at least one wiring circuit to another entity, such as a processing unit. The circuit board may be configured to receive a current through the wiring circuit when in use. The current and / or voltage through the wiring circuit may be affected by the electrical characteristics of the wiring circuit. Such electrical characteristics may change according to the force acting on the circuit board.

[0014] A circuit board including at least one wiring circuit can be designed so that the electrical characteristics depend on the flexing of the circuit board. The length of the wiring circuit can be selected to be appropriately long so that this effect is large enough to be measured with appropriate accuracy. In one embodiment, the wiring circuit can be made as long as practical on the circuit board.

[0015] Furthermore, using a wiring circuit may have advantages over using a piezoelectric material. Piezoelectric films have high temperature sensitivity, which may cause the detection sensitivity to vary depending on the temperature conditions where the collision detection device is placed.

[0016] Furthermore, piezoelectric diaphragms are not suitable for static conditions and only measure fluctuations in conditions. Bending moment fluctuations generate a voltage, which generates a current, but no current flows from the piezoelectric diaphragm during the stable movement of the telescopic column. However, with the inventive solution, during the stable movement and stop of the adjustable furniture item, a voltage can be present on the wiring circuit, thereby also causing a measurable current.

[0017] The collision that the collision detection device is configured to detect may be defined as an increase in load on the adjustable furniture item and / or the collision detection device. The collision detection device may thus be configured to detect such loads and / or load changes. In some embodiments, the collision detection device may be defined as a load detection device for an adjustable furniture item. The terms "collision detection device" and "load detection device" may thus be used interchangeably.

[0018] In one embodiment, the electrical characteristic is dependent upon the resistance mechanically resisting movement of the adjustable furniture item.

[0019] In one embodiment, the collision detection device may include a processing unit or another unit (such as a power supply) that may be configured to supply current through at least one wiring circuit of the circuit board and apply a voltage thereto, and measure an amount of electricity, which may depend on electrical characteristics. In order to measure the amount of electricity, it may involve providing appropriate information to the processing unit, based on which detection can be performed. The processing unit may further be provided with information about a pre-measured correlation between the amount of electricity and the resistance. For example, by applying a known resistance during the movement of an adjustable furniture item and measuring the effect on the amount of electricity, the correspondence can be estimated, which means that the amount of resistance that should be required for detection can be controlled. Thereby, the sensitivity of the collision detection device can be controlled and adjusted, for example due to regulations.

[0020] The processing unit may further register an electrical malfunction in the operation of the collision detection device, such as a short circuit or an open circuit, which may occur due to the application of voltage not only during a collision, but also during steady movement and rest of the adjustable furniture item.

[0021] In one embodiment, the processing unit may be configured to issue a collision event signal based on a measured charge of the at least one wiring circuit. The processing unit configured to measure the charge may provide detection of changes in electrical characteristics caused by forces acting on the collision detection device. The processing unit may be configured to issue a collision event signal based on a measured value of the charge being above or below a predetermined threshold.

[0022] In one embodiment, the processing unit may be configured to control the drive device to stop and / or reverse the movement of the adjustable furniture item in the event of a collision event. A collision event signal may be sent to the drive device and may cause the movement of the drive device to be stopped and / or reversed so as to release the obstacle in the event that the obstacle is clamped between the movable surface and some other object or surface. Information about the conditions during which a collision event should be sent may be provided to the processing device based on an operator's assessment. This may be based on at least one of the following: electrical characteristics of the wiring circuit, the electrical charge, regulations, calibration of the collision detection device, the weight of the table top, and the nature of the adjustable furniture item. The threshold value of the electrical charge for sending a collision event signal may vary depending on whether the adjustable furniture item is in a retracted state, an extended state, or any intermediate state.

[0023] In one embodiment, the wiring circuit on the circuit board may be a first wiring circuit arranged on a first side of the circuit board, and the circuit board may further include a second wiring circuit on a second side of the circuit board, and the electrical characteristics of both the first wiring circuit and the second wiring circuit may depend on the flexure of the circuit board.

[0024] Having two wiring circuits can consider the electrical characteristics of two wiring circuits and measure the voltage difference between the wiring circuits. Further, two wiring circuits (both of which are affected by the same force acting on the retainer and the circuit board) can provide the corresponding change of electrical characteristics, thereby causing a double change that can be detected. These wiring circuits can be arranged and connected so that the voltage on one wiring circuit of these wiring circuits increases when the other wiring circuit decreases, and vice versa. Therefore, the voltage difference can be greater than the voltage on a wiring circuit, thereby improving the accuracy of the relevant voltage measurement. In addition, in the case where one wiring circuit in these wiring circuits has an error and the electrical characteristics of the wiring circuit are not properly responded to the collision, the other wiring circuit can still respond, so that the collision can be successfully detected, which means that the safety of the collision detection device is improved.

[0025] In one embodiment, the processing unit is configured to measure the electrical quantities of the two wiring circuits respectively.

[0026] In one embodiment, the processing unit is configured to estimate the derivative of the electrical quantity of the at least one wiring circuit based on repeated or continuous measurements of the electrical quantity of the at least one wiring circuit. By estimating the derivative, the derivative can be taken into account when determining whether a collision event signal should be issued. By considering both the derivative and the absolute value of the electrical quantity that depends on the electrical characteristics of the at least one wiring circuit, the reliability of the collision detection device to correctly issue a collision event signal can be improved. Both a significant absolute value of the electrical quantity caused by significant deflection of the circuit board and a significant derivative caused by rapid changes in the deflection of the circuit board can indicate the occurrence of a collision.

[0027] In one embodiment, the electrical characteristic of the at least one wiring circuit may be resistance. In one embodiment, the electrical quantity of the at least one wiring circuit may be voltage and / or current.

[0028] The flexing of the at least one wiring circuit may mean a change in the resistance of the at least one wiring circuit. Based on information depending on the amount of the resistance, the collision detection device may signal a collision event. The measured voltage may depend on the resistance of the at least one wiring circuit, and the voltage may thereby indicate whether a collision has occurred.

[0029] In one embodiment, the first part and the second part of the adjustable furniture item may be movable by means of at least one telescopic column. The at least one telescopic column may include at least two telescopic tubes, and a drive device. The first part of the adjustable furniture item may be an inner tube of one of the at least one telescopic column, and the second part of the adjustable furniture item may be a second tube of one of the at least one telescopic column. The at least one telescopic column may be configured to be arranged vertically. A surface, such as a tabletop, may be height-adjustable by means of the at least one telescopic column. With the inventive solution, the detection does not delay the time taken for the tube to flex, as may be the case with some prior art. The telescopic tube may be designed to have a low deflection, since a greater deflection of the tube may impair the operation of the telescopic tube and require an undesirably tilted movable surface. Therefore, a detection depending on the deflection of the circuit board may be relatively advantageous, which detection in the case of the present invention may be designed to have sufficient flexibility for a fast response to the occurrence of a collision.

[0030] In one embodiment, the furniture item may be movable by means of a lever function. A first part of the drive device may be in at least indirect contact with a first part of the furniture item, and a second part may be in at least indirect contact with a second part of the drive device. During the movement of the furniture item, a mechanical force may be transmitted from the first part of the drive device to the second part of the drive device, thereby causing the first part to move relative to the second part of the furniture item. The first part of the drive device may, for example, push or pull the second part of the drive device. Alternatively, the mechanical force may be transmitted directly from the first part of the drive device to one of a plurality of other furniture components. The first part of the drive device may, for example, push or pull the second part of the furniture item, thereby causing the first part to move relative to the second part of the furniture item.

[0031] In one embodiment, the adjustable article of furniture is a bed or a chair and the first component of the adjustable article of furniture is a backrest.

[0032] In one embodiment, the retainer is configured to be arranged in contact with a tube of the at least one tube of the telescopic column.

[0033] By the contact between the retainer and the inner surface, there may be a contact force between the retainer and the tube. This contact force together with the resistance from the drive device may generate a bending moment, and the circuit board may bend due to this bending moment. When arranged on the inner surface of the inner tube, the retainer may be substantially fixed relative to the tube at least at a part of the retainer at the attachment point to the tube. Thus, a force from, for example, the drive device, acting on another part of the retainer, may provide a torque between the contact points between the drive device and the tube accordingly. This torque thus causes deflection in the retainer.

[0034] In one embodiment, the retainer is configured to be arranged on the adjustable furniture item by a snap-fit ​​function or by a screwing arrangement.

[0035] In one embodiment, the holder is configured to be arranged on one of the telescopic tubes by a snap-fit ​​function or by a screwing arrangement.

[0036] In particular, the snap-fit ​​function may provide for efficient mounting of the retainer on the telescopic column and may facilitate removal of the retainer for maintenance or replacement. The retainer may be arranged by means of a plurality of components on the retainer and a plurality of corresponding components on the longitudinal ends of the tubes of the telescopic column by means of the snap-fit ​​function or screwing means. In one embodiment, the retainer may be arranged at the longitudinal ends of the inner telescopic tube. In one embodiment, the retainer may include a through hole configured to allow a portion of the drive device to extend through the retainer.

[0037] The contact between the portion of the drive means and the hole may provide a force from the drive means to be transmitted to the holder. The force from the drive means may come from a motor and / or from resistance to contact between the movable surface and an obstacle. The circuit board may be provided with a corresponding hole or opening so that the drive means may extend therethrough. In an alternative embodiment, the holder and the circuit board may be provided with a corresponding recess or opening at a side portion of each entity so that the drive means may extend through or through the collision detection device when arranged in the adjustable furniture item.

[0038] In one embodiment, a roller bearing or a sliding bearing is arranged between a part of the drive device and the retainer. The roller bearing or the sliding bearing can enable the drive device to rotate relative to the collision detection device. However, the roller bearing can allow at least longitudinally oriented forces to be transmitted from the drive device to the retainer.

[0039] In one embodiment, the circuit board may extend outside the holder on at least one side of the holder. A larger circuit board may allow for longer wiring circuits and thereby provide a stronger correlation between the electrical characteristics and the flexure of the circuit board, thereby contributing to a higher accuracy of the collision detection device.

[0040] In one embodiment, the processing unit may be configured to calibrate for forces between the holder and the item of furniture by repeatedly or continuously measuring electrical characteristics of the wiring circuit during extension and / or retraction of the telescoping column.

[0041] Calibration of the processing unit may contribute to a higher accuracy of the collision detection device. If the roughness of the surface of the furniture item changes, such a surface of the tube of the telescopic column may cause a change in the resistance to the movement of the telescopic column and thereby in the bending moment applied to the circuit board. This may thus be a risk of false detections. By calibrating the collision detection device during the movement of the furniture item, such as the contraction and / or extension of the telescopic column, such changes may be taken into account. Furthermore, the roughness of the surface of the furniture item may change due to wear. By calibration, the effects of wear may also be reduced and taken into account, which may otherwise mean unreliability of the collision detection device, possible false detections and / or failures when detecting collisions.

[0042] In one embodiment, the circuit board may be pre-biased on the holder. In one embodiment, the holder may be shaped to hold the circuit board in a bent configuration in the rest position. The circuit board being pre-biased may enhance the response of the flexure of the circuit board to the varying forces from the holder, as the circuit board may be more pliable in a slightly flexed state. Thus, the detection of forces acting on the collision detection device may be faster and more sensitive.

[0043] In one embodiment, the holder may include at least two edge clamps configured to clamp an edge of the circuit board to the holder, and the holder may include a protrusion such that the circuit board is held on the protrusion in a bent configuration.

[0044] In one embodiment, the collision detection device may be configured to be able to detect a force corresponding to a weight of 40 kg.

[0045] Being able to detect such forces is important for the safety of users of movable surfaces. This may also be in compliance with regulations. Some prior art solutions are not able to detect collisions accompanied by such small forces.

[0046] In one embodiment, the furniture item may comprise several drive means. For example, the furniture item may comprise a plurality of telescopic columns, and one or several of these telescopic columns may comprise a drive means.

[0047] In one embodiment, a plurality of detection devices may be used for one furniture item. For example, the detection device may be arranged in one or several telescopic columns of the furniture item.

[0048] In one embodiment, several detection devices may share one processing unit. One processing unit may apply a current through the wiring circuits of several of the detection devices and apply a voltage on these wiring circuits. Further, the processing unit may measure the electrical quantities of several detection devices. The processing unit may evaluate whether to issue a collision event signal based on the measured electrical quantities of the wiring circuits of several detection devices. This evaluation may be performed individually or in combination based on the measured electrical quantities from several detection devices. Based on the detected collision, a control signal may be sent to one or several drive devices to stop and / or reverse the movement of the furniture item.

[0049] According to a second aspect of the present invention, a method for detecting a collision of a furniture item is provided, wherein the method comprises the following steps: providing a collision detection device according to any one of the above-mentioned embodiments on the furniture item; measuring the charge of a wiring circuit during movement of the furniture item; and issuing a collision event signal based on the measurement.

[0050] The advantages described for the collision detection device also apply to the method.

[0051] In one embodiment, the method may include the step of stopping and / or reversing the movement of the furniture item based on the measurement of the charge and / or the collision event signal.

[0052] In one embodiment, the method may further include the step of comparing the measured electrical charge to a predetermined threshold, wherein the predetermined threshold may vary along the length travel of the telescopic column based on a calibration curve providing a function of load on the collision detection device and travel position in a state where there is no external load on the telescopic column. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] The invention will be described in more detail hereinafter with reference to the accompanying drawings, in which:

[0054] Figure 1 The diagram shows a cross-sectional view of a telescopic column according to an embodiment of the present invention, which is movable by means of a drive device and to which a collision detection device can be applied.

[0055] Figure 2 A perspective view of a sensor unit of a collision detection device according to an embodiment of the present invention is illustrated.

[0056] Figure 3 A lateral side view of a sensor unit of a collision detection device according to an embodiment of the present invention is illustrated.

[0057] Figure 4 The figure shows a lateral side view of a sensor unit of a collision detection device according to an embodiment of the present invention relative to a driving member (spindle) of a driving device of a telescopic column.

[0058] Figure 5 The diagram shows a longitudinal side view of a sensor unit of a collision detection device according to an embodiment of the present invention relative to a drive member (spindle) of a drive device of a telescopic column.

[0059] Figure 6 The figure shows a top side view of a sensor unit of a collision detection device according to an embodiment of the present invention relative to a driving member (spindle) of a driving device of a telescopic column.

[0060] Figure 7 A perspective view of a collision detection device according to an embodiment of the present invention relative to an inner tube of a telescopic column is shown.

[0061] Figure 8 A perspective view of a collision detection device according to an embodiment of the present invention relative to an inner tube of a telescopic column is shown.

[0062] Fig. 9 A top view of a first wiring circuit of a circuit board of a collision detection device according to an embodiment of the present invention is illustrated.

[0063] Fig.10 A detailed top view of the connection terminals of the upper first wiring circuit on the upper side of the circuit board of the collision detection device according to the embodiment of the present invention is illustrated.

[0064] Fig.11 A top view of a second wiring circuit of a circuit board of a collision detection device according to an embodiment of the present invention is shown.

[0065] Fig.12 A detailed top view of a connection terminal of a second wiring circuit of a circuit board of a collision detection device according to an embodiment of the present invention is illustrated. DETAILED DESCRIPTION

[0066] The present invention will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the present invention are shown. However, the present invention may be implemented in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be comprehensive and complete and will fully convey the scope of the present invention to those skilled in the art. In the accompanying drawings, the same reference numerals refer to the same elements.

[0067] According to one embodiment of the invention, the furniture item can be moved by means of one or several telescopic columns 1, wherein the collision detection device can be arranged on one or several telescopic columns. In the illustrated embodiment, the adjustable furniture item is exemplified as a telescopic column 1. The same inventive concept is equally applicable to other adjustable furniture items. According to such an embodiment, Figure 1 A telescopic column 1 is shown, which comprises an inner tube 14 and an outer tube 16. The telescopic column may also comprise an intermediate tube 17. In a common embodiment, a horizontal surface, such as a tabletop, is movable in a direction D1 by means of one or several telescopic columns 1, which are arranged vertically. The telescopic tubes 14, 16, 17, of which the inner tube 14 in the illustrated embodiment is the tube closest to the height-adjustable surface, are movable by means of a drive device 11. The drive device 11 comprises an electric motor 13, and drive members 12, 18, 19 extending through the telescopic tubes 14, 16, 17 to cause the contraction and extension of the telescopic column 1. The present invention may be equally applicable to telescopic columns constructed in a different manner, such as with an outer tube closest to the height-adjustable surface.

[0068] A collision detection device 2 comprising a sensor unit 3 is arranged in the telescopic column 1 . Figure 2 and Figure 3 The sensor unit 3 of the collision detection device 2 is illustrated from two different perspectives. The sensor unit 3 is configured to be arranged in the inner tube 14 of the telescopic column 1. The sensor unit 3 has a holder 38 which can be attached to the inner tube 14 by means of a component 32 arranged on the holder and a corresponding component arranged on the inner tube 14 by a snap-fit ​​function.

[0069] On the holder 38, the circuit board 31 is arranged by means of edge clamps 33, which clamp the circuit board 31 to the holder 38. The edge clamps 33 may allow the circuit board 31 to bend by being arranged on the lateral sides of the circuit board 31. The relationship between the distance between the edge clamps and the length of the circuit board and / or the protrusion 39 may mean that the circuit board 31 is pre-biased, causing the circuit board 31 to bend to a certain extent even when the telescopic column is at rest. It can be seen that the circuit board 31 has a flexure above the protrusion 39 and at the bottom of the protrusion 39. Figure 3 The edge clamps 33 have vertices between them.

[0070] On both sides of the circuit board 31, wiring circuits are provided on the substrate. Fig. 9 and Fig.11 4 shows a first wiring circuit 40 on the upper side of the circuit board 31 and a second wiring circuit 42 on the lower side. The connection terminals 36 are respectively Fig.10 and Fig.12 31. The wiring circuits 40 and 42 may include a material having a high electrical conductivity. The wiring circuits 40 and 42 may be constructed to have many turns and to be substantially as long as possible given the area of ​​the circuit board 31. When the circuit board 31 flexes, the orientation of different portions of the wiring circuit 40 relative to each other changes. By supplying a current through the wiring circuits 40 and 42, as described below, the voltage on the wiring circuits 40 and 42 varies with their resistance, and thus the voltage may vary with the flexing of the circuit board 31. The ends of the wiring circuits may be connected via the connection terminals 36 of the circuit board 31 so that current is supplied through the wiring circuits 40, and so that when the voltage on one of the wiring circuits is reduced, the voltage on another of the wiring circuits is increased.

[0071] Figures 4 to 6 The arrangement of the sensor unit 3 relative to the drive component (spindle) 12 of the drive device 11 is illustrated from different perspectives. The sensor unit 3 has a hole 37 extending through the holder 38 and the circuit board 23. The hole 37 allows the spindle 12 to extend through the sensor unit 3. A roller bearing 34 is arranged between the spindle 12 and the hole 37, which allows the spindle 12 to rotate relative to the sensor unit 3. The sensor unit 3 may therefore not rotate relative to the telescopic column 1 during the movement of the telescopic column 1. However, the roller bearing 34 allows the force to be transmitted from the spindle 12 to the circuit board 31. If the movement of the telescopic column 1 is hindered by resistance, the resistance is transmitted to the circuit board 31 by the drive device 11 (including the spindle 12). Since the sensor unit 3 is attached to the inner surface 15 of the inner tube 14, the resistance means a bending moment on the circuit board 31, the deflection of which is changed by this bending moment. The resistance may come from the collision between the tabletop or any telescopic column 1 and an obstacle.

[0072] The collision detection device 2 may further include a processing unit 21. The circuit board 31 is connected to the processing unit 21 from the connection terminals 36 by means of a wiring harness 35. Figure 7 and Figure 8 The processing unit is shown in FIG. 1 together with the drive device 11, the electric motor 13 and the inner tube 14. The sensor unit 3 is Figure 8 As can be seen in FIG. 1 , the sensor unit is in contact with the inner surface 15 of the inner tube 14. The collision detection device 2 can be moved in the direction D1 by means of a drive device 11 driven by an electric motor 13 along with the movement of the inner tube 14 and the height-adjustable surface. The collision detection device 2 can also be mounted on the underside of the movable surface. The processing unit 21 can be mounted to the movable surface, for example, by a fastening device (such as a tightening device).

[0073] The processing unit 21 and the drive device 11 are powered by the power supply terminal 23. The processing unit 21 can supply current to the circuit board 31 through the wiring harness 35 and cause the current to flow through at least one wiring circuit 40. The processing unit 21 can measure an amount of electricity that depends on the electrical characteristics of the at least one wiring circuit, such as a voltage connected to both ends of the circuit board 31. A threshold value related to the amount of electricity can be provided to the processing device, and the processing device is configured to issue a collision event signal above or below the threshold. Alternatively, the processing device 21 can issue a collision event signal based on repeated or continuous measurements of the amount of electricity during the movement of the telescopic column 1. When and whether to issue a collision event signal can also be based on other information, which is provided to the processing unit 21 according to the calibration of the collision detection device 2. The information may include one or more of the following information: information from earlier measurement results during one or more calibrations of the collision detection device 2, information about the circuit board 31, the weight of the desktop or the components of the telescopic column 1, and the correlation between the amount of electricity provided for different positions of the telescopic column 1 and the force resisting the movement of the desktop and the telescopic column 1. The calibration may be performed as a calibration procedure before an operator uses the collision detection device 2 or during a user's regular use of the telescopic column 1. The calibration may be performed during partial or full extension and / or retraction of the telescopic column 1.

[0074] Furthermore, the processing unit 21 can control the movement of the drive device 11. A collision event signal can be emitted by the processing unit 21, whereby it stops and optionally also reverses the movement of the drive device 11.

[0075] Within the inventive concept of collision detection disclosed above, a collision control method for an adjustable furniture item may be provided. In the method, a collision detection device may be used, which may be a collision detection device according to any of the embodiments discussed above, or another collision detection device configured to detect the absolute value of the load on the adjustable furniture item.

[0076] The method may comprise the step of providing a calibration curve. Providing the calibration curve may be performed by moving the adjustable furniture item through a full length stroke, i.e. by moving it from a fully retracted state to a fully extended state, or vice versa. In one embodiment, the adjustable furniture item may be movable in two ways, i.e. from one of the end positions to the other end position, and back. During the movement of the adjustable furniture item to generate the calibration curve, the adjustable furniture item may be free of external loads, e.g. free of external loads other than the load provided in normal use. If the adjustable furniture item is, for example, a telescopic column arranged in a height-adjustable table, the calibration curve may be provided during movement with no other loads other than internal loads in the column and components of the table, such as the table top.

[0077] During the movement of the adjustable furniture item, the collision detection device can record the load to which it is exposed during the movement. This recording of the load can form a calibration curve. The load recording can be performed at predetermined intervals (such as every 3mm to every 10mm) along the length of travel. The predetermined interval can also be smaller, such as every millimeter or every two millimeters. Alternatively, the load recording can be performed continuously along the travel, such as at each pulse of the electric motor that drives the adjustable furniture item to move. In one embodiment, the electric motor can provide three pulses for every millimeter of travel.

[0078] The calibration curve may be provided as a function of the detected load value on the impact detection device and the travel (ie the position of the adjustable furniture item along its length travel) in the absence of any external load or impact on the adjustable furniture item.

[0079] The calibration curve may represent the load on the collision detection device caused by the internal components of the adjustable furniture item. It may in particular be the friction between different components of the adjustable furniture item. Since the friction between the components may vary along the length travel, the calibration curve may generally not be constant or linear, but non-linear.

[0080] The method for collision control of a telescopic column may further include the step of detecting a collision of the telescopic column based on the calibration curve and a recorded current load value provided by the collision detection device. The current load value may be received by the processing unit from the collision detection device. When evaluating whether the current load value may indicate a collision, the processing unit may compare the current load value with the load value of the calibration curve at the current position along the length of travel. The processing unit may be configured to stop the movement of the adjustable furniture item (and possibly resume the movement by a predetermined amount) at a threshold value that may depend on the load value in the calibration curve at the corresponding position along the length of travel.

[0081] As an illustrative example, at a position 5 cm from the most retracted position of the adjustable furniture item, the calibration curve indicates an internal load of 8 kg. The processing unit can be configured to issue a collision event signal representing a detected collision if a load above 15 kg is detected. During the movement of the adjustable furniture item, the collision detection device detects a load of 20 kg. The external load is therefore 12 kg and should not be detected as a collision. The processing unit uses information from the calibration curve to determine that the detected external load is below the threshold. At another position along the length travel (such as 30 cm from the retracted position), the calibration curve specifies a lower internal load of 3 kg. During the movement of the adjustable furniture item, the collision detection device again detects a load of 20 kg. Since the internal load at this position according to the calibration curve is 3 kg, the load detected by the processing unit is interpreted as a 17 kg external load, which is above the threshold of 15 kg. The processing unit can then issue a collision event signal and stop the movement of the adjustable furniture item.

[0082] In one embodiment, the collision control method can be further adapted to the initial load on the furniture when the movement starts. The calibration curve can be temporarily reconfigured or replaced based on the current load detected at the beginning of the movement of the adjustable furniture item, or the threshold value can be re-determined. For example, in the case of a table including telescopic columns, the table can be provided with several objects, such as computer equipment, when in normal use. In the case of an adjustable bed, the bed can be occupied by a person. This provides an initial external load on the adjustable furniture item, which can be taken into account when determining whether a collision occurs. If an initial load of 20 kg is provided on the adjustable furniture item at the beginning of the movement, the calibration curve can be increased by 20 kg throughout the curve. Alternatively, several calibration curves can be provided, all of which can be based on the original generated calibration curve or separately generated calibration curves, which are suitable for different initial loads. When the adjustable furniture item starts to move with an initial load of 20 kg, a collision event signal can be issued when a threshold value (e.g., 15 kg) above the calibration curve load at the current stroke position is exceeded.

[0083] In one embodiment, a set of calibration curves representing different initial loads may be provided. Such initial loads may be, for example, 0 kg, 20 kg and maximum load (representing the maximum allowed load according to the specification). These calibration curves may be generated separately.

[0084] The calibration curve(s) may be generated after the adjustable furniture item is manufactured, but before the end user begins to use the furniture. The calibration curve(s) may be unique for each copy of the movable component of the furniture. During use of the adjustable furniture item, the components of the adjustable furniture item may be exposed to wear, causing the friction between the components to change. Thus, it may be necessary to update the calibration curve(s) during the life of the adjustable furniture item. The updating of the calibration curve(s) may be performed by performing the same movement of the adjustable furniture item as when the initial calibration curve(s) was generated and recording the load on the adjustable furniture item without any external load.

[0085] Alternatively, the processing unit may be configured to adjust the calibration curve(s) over time. For example, the processing unit may be configured to continuously compare the detected load records with the load signatures in the calibration curve(s) and adjust the curves if no collisions are detected, thereby determining repeatability deviations from the calibration curve(s). Alternatively, such comparison is performed periodically. The processing unit may, for example, be configured to adjust only instances of the calibration curve(s) that are close to lower loads. When adjusting the calibration curve(s), the processing unit may adjust one or more load values ​​for one or more corresponding travel positions.

[0086] According to one aspect, a collision control method for an adjustable furniture item may be provided, the method comprising the step of receiving a current load value signal from a collision detection device during movement of the adjustable furniture item, the load value signal representing a detected load on the collision detection device. The collision control method further comprises the step of comparing the received load value with a calibration curve, wherein the calibration curve provides a function of the load value on the collision detection device and the travel position in a state without any external load or collision on the adjustable furniture item. Finally, the collision control method comprises the step of determining whether to stop the movement of the adjustable furniture item based on the comparison and a predetermined threshold.

[0087] In one embodiment, the collision control method can be performed by a processing unit in an adjustable furniture item. A current load value signal can be received from a collision detection device arranged in the adjustable furniture item. In an embodiment where the adjustable furniture item includes several telescopic columns, the processing unit can receive the current load value signal from a collision detection device arranged in the same telescopic column as the processing unit, or from a collision detection device arranged in another telescopic column. In one embodiment, the collision detection device can be a collision detection device according to any embodiment described herein. The calibration curve can be stored in the processing unit, or in a memory unit connected to the processing unit. In one embodiment, an adjustable furniture item having two or more telescopic columns can include a processing unit in each telescopic column. The processing unit of the telescopic column can provide a corresponding signal, such as a collision detection signal. The processing units can each communicate with the memory unit, or can each store the calibration curve. The adjustable furniture item can further include a central processing unit configured to receive and process signals from the processing units in each telescopic column.

[0088] According to another aspect, a calibration curve generating method for generating a calibration curve for an adjustable furniture item may be provided. The method may include the step of providing a load sensing device, the load sensing device being arranged on or in the adjustable furniture item and being configured to provide a signal representing a current load on the load sensing device. The method may further include the step of recording a signal from the load sensing device during movement of the adjustable furniture item from one end position to another end position while the adjustable furniture item is not exposed to any external load. The recording of the signal from the load sensing device may form a calibration curve of load as a function of travel position of the adjustable furniture item.

[0089] An external load may be any load applied from an external object or entity to the adjustable furniture item or the device in which the adjustable furniture item is arranged. The loads to be detected during the generation of the calibration curve may be mainly loads from the weight of the adjustable furniture item or the device itself, and / or friction between parts of the adjustable furniture item, thereby causing varying loads on the load detection device. The movement of the adjustable furniture item during the generation of the calibration curve may be performed in only one way or in both ways, i.e. from one end position to the other end position and back.

[0090] The end position may refer to one of a most retracted state of the adjustable item of furniture and a most extended state of the adjustable item of furniture.

[0091] The term “collision detection device” as used throughout this document may be used interchangeably with the term “load detection device.” Further, in some embodiments, the load detection device described may be formed by a collision detection device according to any embodiment disclosed herein.

[0092] By using calibration curves when controlling the movement of adjustable furniture items and detecting collisions, loads caused by internal components and their various forms can be compensated, making collision detection more accurate and precise. More accurate and precise collision detection can further enable the use of lower thresholds for collision detection while maintaining reliability. It can further enable high-speed detection, thereby enabling rapid reaction to detected collisions.

[0093] Fig.13 An example calibration curve C1 generated for a telescoping column is illustrated. The calibration curve C1 represents the detected load L caused by the internal components of the adjustable furniture item as a function of the travel position P. The load detected during the generation of the calibration curve C1 varies along the length travel of the adjustable furniture item. At different travel positions, the friction between the components in the adjustable furniture item may be different.

[0094] Fig.13 A second calibration curve C2 is further shown which represents the calibration curve for a predetermined initial load. When the adjustable furniture item is used and starts to move, the initial load on the adjustable furniture item is determined based on the current load detected on the detection device. In case the determined initial load is at the predetermined initial load level of the second calibration curve C2, the second calibration curve C2 will be used to detect a collision of the adjustable furniture item. The method may comprise providing further additional calibration curves for different predetermined initial loads. The initial load may be the load on the adjustable furniture item during use. The initial load may not affect the shape of the calibration curves C1, C2 but only the level of the calibration curves C1, C2 on the y-axis, e.g. Fig.13 As shown in the figure.

[0095] Fig.14 A flow chart of a collision control method 100 for an adjustable furniture item is illustrated. The collision control method 100 comprises the step of receiving 102 a current load value signal from a collision detection device during movement of the adjustable furniture item. The load value signal represents a detected load on the collision detection device. The collision control method 100 further comprises the step of comparing 104 the received load value with a calibration curve C1, C2, wherein the calibration curves C1, C2 provide a function of the load value on the collision detection device and the travel position in a state in which there is no external load or collision on the adjustable furniture item. Finally, the collision control method 100 comprises the step of determining 106 whether to stop the movement of the adjustable furniture item based on the comparison 104 and a predetermined threshold value (or a combination of two or more predetermined threshold values).

[0096] Fig.15A flow chart of a calibration curve generating method 200 is illustrated. The calibration curve generating method 200 comprises the step of providing 202 a load detecting device, which is arranged on or in an adjustable furniture item, the load detecting device being configured to provide a signal representing the current load on the load detecting device. The calibration curve generating method 200 further comprises the step of recording 204 the signal from the load detecting device during movement of the adjustable furniture item from one end position to another end position while the adjustable furniture item is not exposed to any external load. The calibration curve generating method 200 further comprises the step of generating 206 a calibration curve as a function of the recorded load values ​​and the travel position of the adjustable furniture item. The recording 204 and the generating 206 of the calibration curves C1, C2 may be performed by a processing unit in the adjustable furniture item. The travel position may be known to the processing unit based on the control of the movement of the adjustable furniture item by the processing unit.

[0097] In the drawings and specification, preferred embodiments and examples of the invention have been disclosed, and although specific terms are employed, they are used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention being set forth in the following claims.

Claims

1. A collision detection device (2) configured to be arranged in an adjustable furniture item, the adjustable furniture item comprising a drive device (11) and a first part (14) and a second part (16) movable relative to each other, the collision detection device being configured to detect a collision during movement of the adjustable furniture item, the collision detection device (2) comprising: a retainer (38) configured to be arranged, in use, on one of the first and second parts (14, 16) of the adjustable furniture item to at least indirectly contact a portion of the drive means (11); - a circuit board (31) arranged on the holder (38), the circuit board (31) comprising a wiring circuit (40) on at least one side thereof; wherein the retainer (38) is configured to transmit a force from the drive device (11) acting on the retainer (38) to the circuit board (31) when arranged on the adjustable furniture item, so that the force means a deflection of the circuit board (31); and The wiring circuit (40) is configured to have electrical characteristics that depend on the flexure of the circuit board (31).

2. The collision detection device (2) according to claim 1 further comprises a processing unit (21), which is configured to apply a voltage to the at least one wiring circuit (40) and measure an amount of electricity that depends on the electrical characteristics of the at least one wiring circuit (40).

3. The collision detection device (2) according to claim 2, wherein: The processing unit (21) is configured to issue a collision event signal based on the measured electrical quantity of the at least one wiring circuit (40).

4. A collision detection device (2) according to any preceding claim, wherein: The wiring circuit (40) on the circuit board (31) is a first wiring circuit (40) arranged on a first side of the circuit board (31), and the circuit board (31) further includes a second wiring circuit (40) on a second side of the circuit board (31), and wherein the electrical characteristics of both the first wiring circuit (40) and the second wiring circuit (42) depend on the flexure of the circuit board (31).

5. The collision detection device (2) according to claim 4, wherein: The processing unit (21) is configured to measure the electrical quantities of the two wiring circuits (40; 42) respectively.

6. The collision detection device (2) according to any one of claims 2 to 5, wherein: The processing unit (21) is configured to estimate the derivative of the electrical quantity.

7. A collision detection device (2) according to any preceding claim, wherein: The electrical characteristic of the at least one wiring circuit (40) is resistance.

8. A collision detection device according to any preceding claim, wherein: The adjustable furniture item comprises at least one telescopic column, the first component being a first tube of the at least one telescopic column and the second component being a second component of the telescopic column, wherein the retainer (38) is configured to be arranged in contact with one of the tubes of the telescopic column (1).

9. The collision detection device (2) according to claim 8, wherein: The retainer (38) is configured to be arranged on the furniture item or a part of the drive device by a snap-fit ​​function or a screwing device.

10. The collision detection device (2) according to any one of claims 3 to 9, wherein: The processing unit (21) is configured to calibrate the force between the holder (38) and the adjustable furniture item or the drive device by repeatedly or continuously measuring an electrical characteristic of the movement of at least one wiring circuit of the adjustable furniture item.

11. A collision detection device (2) according to any preceding claim, wherein: The circuit board (31) is pre-biased on the holder (38).

12. The collision detection device (2) according to claim 11, wherein: The retainer (38) is shaped to retain the circuit board (31) in a bent configuration in the rest position.

13. A method for detecting a collision of an adjustable furniture item (1), the method comprising the following steps: Providing a collision detection device (2) according to any one of claims 1 to 12 on an adjustable furniture item (1), measuring the electrical quantity of the wiring circuit (40) during the movement of the adjustable furniture item (1), A collision event is signaled based on the measurements.

14. The method according to claim 13, further comprising the step of stopping and / or reversing the movement of the adjustable furniture item (1) based on the collision event signal.

15. The method according to claim 13 or 14, further comprising the step of comparing the measured electrical quantity with a predetermined threshold and issuing the collision event signal based on the comparison, wherein: The predetermined threshold value varies along the length travel of the telescopic column based on a calibration curve (C1, C2), which provides a function of the load on the collision detection device (2) and the travel position when the telescopic column (1) has no external load.

Images