SE527764C2 - Height adjustable furniture and method of raising and lowering height adjustable furniture - Google Patents

Abstract

The invention refers to a vertically adjustable furniture unit (1) with at least two vertically adjustable legs (2, 3) each with an outer leg section (4), an inner leg section (5) and a foot (6). Each leg (2, 3) ha a drive motor (15) for raising and lowering the leg (2, 3). The furniture unit (1) has a signal button (10) connected to one leg (2), the master leg, by means of which the user gives signals (33) for raisin and lowering, respectively. The signal (33) is transmitted further to the other leg(s) (3), the slave leg(s), by the intermediary of a communication conductor (12) through which exchange of information signals takes place between the master leg (2) and the slave leg(s) (3). Information signal contain information on the movement of the master leg (2) and the slave leg(s) (3), for a comparison between the movement of the slave leg(s) (3) in relation to the master leg (2), whereafter the corresponding movement is generated in the slave leg(s) (3). a The invention also refers to a method intended to raise or lower the furniture unit (1).

Description

527 764 2 The possibilities for adapting the workplaces are increasing and demand has now begun to spread to such workplaces that have not previously been adaptable, such as alarm centers and spaces for process controls. In these workplaces, shift work usually takes place and an adaptation of the workplace should therefore be made to the respective users, ie a couple of times a day.

Smaller furniture can be provided with only one extendable leg, for example of the pillar type. If the furniture is larger, however, two or fl your legs are often required for it to be stable, for example a table with an elongated top. When fl your legs are arranged on the furniture, it is desirable that they are at all times approximately the same length, both during and after a change in height and regardless of whether the furniture is raised or lowered. The reason for this is that it is generally desirable for the top of the furniture, typically a table top, to remain substantially horizontal. In addition, an excessive difference in the length of the legs would cause them to "jerk" and the ongoing upward or downward movement would be blocked. What one wants to achieve is thus quite clear, but it has proved quite difficult to achieve this result in practice.

Manual raising or lowering of the legs is in practice excluded in the case of continuous height adjustments, as it is either difficult for a single person to adjust the height of your legs at the same time or because it is difficult to get two or your people to coordinate their actions. to increase the adjustment of each leg with sufficient accuracy. Possibly this can work if the height of the furniture is adjustable only between a few, well de fi nied, positions.

Typically, therefore, some electrically driven control system must control the movement and motors must be used to effect the shortening or extension of the legs. From experience it has been possible to state that different motors work somewhat differently, possibly due to the fact that the furniture is not completely symmetrically loaded. In addition, the motors cannot be expected to start momentarily when ordered to do so by the control system. This can make it difficult to achieve an equal change in the length of the furniture legs. Another problem is that different types of control equipment are required for furniture with different numbers of legs. This is impractical, not least with regard to the stock of manufacturers of control equipment and furniture, and a rebuilding of existing workplaces is made considerably more difficult, as the control equipment must be replaced if the number of legs is increased.

TROUBLESHOOTING It is thus desired to achieve a highly adjustable piece of furniture with a control system that is easy to modify to different number of legs. At the same time, the system and the furniture must be well-functioning in that an equal change in height is carried out on all the legs of the furniture.

TROUBLESHOOTING The object underlying the invention is achieved if the initially indicated highly adjustable piece of furniture is given the indicia that one of the legs, called the master leg, is arranged to receive the input signal and perform a movement accordingly, that a communication line is arranged for exchange of information. about the primary leg and the movements of the other legs and that the other legs are arranged to compare their own positions with the movement of the master leg and achieve a corresponding movement in each leg. Regarding the method, the object is achieved if this is characterized in that the signal is applied to one of the legs, which is a primary leg; causing the primary leg to perform a movement corresponding to the received signal; that in the primary leg an information signal is generated with information about performed movement; that the information signal is routed to the other legs; that in each other leg an iron movement is made between the position of this leg and the position of the primary leg; and that each other leg is caused to move until it has assumed the same position as the primary leg.

COMPILATION OF DRAWING FIGURES The invention will now be described on the basis of the attached drawings.

These show: fi g 1 a perspective view obliquely from below of an exemplary piece of furniture; 2 g 2 a perspective view of a leg, partly cut-up, included in the furniture; fi g 3 an exploded view corresponding to fi g 2; 4 g 4 is a detail view of an upper portion of a partially cut bone; and fi g 5 a fl circuit diagram of the control system in the highly adjustable piece of furniture.

PREFERRED EMBODIMENT I fi g 1 is shown in perspective obliquely from below a table 1, which is an example of such a highly adjustable piece of furniture to which the invention relates. The table 1 could of course also be some poor piece of furniture, for example a control panel, a shelf or a cabinet.

The table 1 has two legs 2, 3, each having an outer leg part 4 and an inner leg part 5 and each foot 6. Both legs 2, 3 each comprise, in Fig. 1 not visible, drive motor, and for power supply of these at least one adapter is arranged 7 and a cable 8, which leads to at least one accumulator 9. In the preferred embodiment, an accumulator 9 is arranged at the respective legs 2, 3 and must be supplied with power either by each mains connection 7, 8 or by one and the same mains connection supplying both the accumulators 9. In this respect, the connection to the left accumulator in fi g 1 has been omitted for the sake of clarity.

The table itself would operate with only one accumulator 9, but its performance would decrease, in that a more limited lowering and / or raising can be performed before the accumulator 9 has to be recharged.

A signal button 10 is connected via a signal line 11 to one leg 2.

From the signal creep 10, the user gives signals as to whether an increase or decrease of the table is desired. When the button 10 is released, this is perceived as a stop signal and the upward or downward movement is interrupted.

Between the legs 2, 3 extends a communication line 12 in the form of a bus. The bus is made up of a number of wires for parallel transmission of electrical signals. The bus as such allows electrical signals to be transmitted on all wires simultaneously. In the preferred embodiment, this will typically not happen, since each line included in the bus has been given a particular function and some of these functions are mutually exclusive. On the right leg of the clock, an unused recess 13 for the input signal from the signal folder 10 can be seen. The left leg 2 has a corresponding recess 13 on the side facing away from the viewer and the signal line 11 is connected to this recess. The signal button 10 is fl surface between the recesses 13, but only one of the recesses 13 may be connected to the signal folders. The socket 13 also works for power supply of the accumulator series 9, although this is not shown in ñg 1.

The side of the leg 2 facing the viewer has two recesses 14 for communication lines 12 and one of these recesses is used in the preferred embodiment. The right leg 3 also has two recesses 14 for communication lines 12, but correspondingly only one of these recesses is used.

Legs 2, 3 are made identical and reversible during assembly in the manner shown in Fig. 1.

In fi g 2 a close-up view of the left leg in fi g 1 is shown in close-up.

Since legs 2, 3 are basically identical, only one needs to be described. In this view, the recesses 14 for the communication line 12 are seen somewhat more clearly.

The leg 2 has an outer part 4 and an inner part 5 slidable therein. A threaded rod 17 connects the inner leg part 5 to the parts which are fixedly arranged in the outer leg part 4, such as a motor 15 and a gear 16. For the sake of simplicity For this reason, the threading of the rod 17 is not marked in fi g 2 and 3. The motor 15 is an electric drive motor, which is driven by current from a mains connection via adapter 7, and the accumulator 9. The rotation of the motor 15 causes an extension or shortening of the leg, i.e. an axial movement of the inner leg part 5 relative to the outer leg part 4. When the inner leg part 5 moves in its maximum inserted position, i.e. in the lowest position of the table 1, a lower part 19 of a zero position sensor 18, which stands in contact with the outer leg part 4 to come into contact with the upper end of the inner leg part 5. 10 15 20 25 527 764 7 The lower end 19 of the zero position sensor 18 is provided with a spring 20. When in contact with the upper end of the inner leg part 5, the spring 20 is compressed and the zero position sensor 18 is displaced a bit upwards. This displacement is detected above the upper end of the motor 15, which will be described in more detail below.

When the contact with the inner leg part 5 ceases, the compressed spring 20 returns the zero position sensor 18. The zero position thus obtained som acts as a starting point from which the rotation of the motor 15 is indicated and also, indirectly, the elongation of the leg 2 relative to the zero position.

Fig. 3 shows an exploded view of the leg 2, substantially corresponding to the view in Fig. 2.

The parts fi- included in the leg 2 appear somewhat more clearly and in addition a circuit board 21, to which the signal line 11 and the communication line 12 are connected, is visible above the motor 15. The circuit board 21 functions as a microprocessor arranged in the leg 2.

Fig. 4 shows a perspective view from above of the leg 2, where the table top has been removed and the leg 2 is partially cut. From the left, the signal line 11 extends from the signal folder 10. The communication line 12 extends to the second leg 3, so that a two-way communication is possible. Another recess 14 is available for connection to additional legs.

An upper part 22 of the zero position sensor 18 is arranged above the circuit board 21 and the zero position sensor 18 extends through it. Arranged on the circuit board 21 is a zero position detector 23. When the zero position sensor 18 and its upper part 22 are pushed upwards at a contact with the upper end of the inner leg part 5, the upper part 22 of the zero position sensor 18 will be displaced relative to the zero position detector 23.

In this case, the circuit board 21 will register that a zero position has been reached and all further movements of the motor 15 and thus the leg 2 are calculated with a starting point from the zero position. To register the rotation of the motor 15, a rotation sensor 24 is provided, which has two halves. When one half will face the rotation detector 25, a pulse is registered, and when the rotation sensor 24 has spun another revolution, so that the same half thereof faces the rotation detector again, a new pulse is registered. In this way, an extension or shortening of the leg is indirectly sensed, since a rotation of the motor has a direct equivalent in an axial extension or shortening of the leg.

Fig. 5 shows a fl fate diagram of the process for raising and lowering the table. The signal button 10 can provide either a signal 33 to the table to move up or a signal to move down. The microprocessor 21 which receives such an input signal 33 becomes controlling for all the legs in the furniture. The leg where this microprocessor 21 is located will be called the master leg or primary leg. The microprocessor 21 is not of any particular type in relation to the corresponding microprocessors 21 in the other legs, but it is the presence of an input signal to this particular leg 2 and this microprocessor 21, which makes the leg 2 a master leg.

When a signal from the signal line 11 is registered by the microprocessor 21, it will send a control signal 26 to the motor 15 in its own leg 2, the master leg. When the motor 15 rotates, pulses 27 will be detected by the rotation sensor 24 and the rotation detector 25 and sent back to the microprocessor 21 in the master leg 2. The pulses 27 are passed on on either of two lines 28, 29 depending on the direction of movement. These lines 28, 29 are arranged in the communication line or the bus 12. All pulses 27 produced by the motor 15 will therefore be sent either to the line 28 if the table moves upwards or to the line 29 if the table moves downwards. Since the bus 12, and thus the lines 28 and 29, are directly connected to the second leg 3 of the table 1, now called the slave leg, the pulses 27 will be read by the microprocessor 21 of this leg. The line 28, 29, on which the pulses 27 occur, the microprocessor 21 of the slave bone 3 indicates whether a movement is to be performed upwards or downwards and the number of pulses indicates the length of the movement.

As soon as the first pulses reach the microprocessor 21 of the slave bone 3, it begins to compare the position of the master bone 2 with the position of the slave bone 3. When the difference between the two legs 2, 3 becomes large enough, i.e. when the master leg 2 moves far enough, the microprocessor 21 of the slave leg 3 will send a control signal 30 to the motor 15 of the slave leg 3. In the same way as the master leg 2, the slave leg 3 to send pulses 31, which correspond to the rotation of the motor 15, and thus the extension of the slave leg 3, to: the microprocessor 21 in the own leg 3.

If the slave leg 3 is too far behind the master leg 2, i.e. if the difference between the length of the master leg 2 and the length of the slave leg 3 is too large, the microprocessor 21 in the slave leg 3 will send a waiting signal on a dedicated line 32 in the bus 12. This signal remains until the difference again falls below a predetermined value, i.e. when the slave leg 3 has caught up with the master leg 2. As soon as a waiting signal 32 is transmitted on the bus 12, the microprocessor 21 in the master leg 2 will sense this signal. The motor 15 of the master leg 2 will be ordered by its microprocessor 21 to pause. When the wait signal 32 has disappeared from the bus 12, the microprocessor 21 of the master leg 2 will again send a control signal 26 to the motor 15 of the master leg 2, provided that there is still an input signal 33 from the signal button 10 on the signal line 11. In the absence of such signal 33, it is assumed that the users of the table are satisfied with the height reached. When the master leg 2 eventually no longer receives any input signal in the signal line 11, its microprocessor 21 will no longer send any control signal 26 to the motor 15. The motor 15 will not be stopped momentarily, but some further rotations will occur. to be performed and pulses 27 are generated.

These pulses 27 will be detected by the microprocessor 21 and passed on on one of the lines 28 or 29 to the slave bone milcroprocessor 21.

The slave leg 3 motor 15 is also unable to stop momentarily. It may therefore happen that this motor 15 rotates a few more revolutions further than the motor 15 of the master leg 2, but also these pulses 31, which are generated in the slave bone 3 will be registered in its microprocessor 21. The number of revolutions of the motor 15 relative to the zero position will always to remain in the respective leg 2, 3 microprocessor 21, so if a difference between the legs 2, 3 occurs in connection with the end of the movement, this difference can be corrected the next time the inner leg receives an input signal from the signal button 10 on the signal line 11.

After periods of power failure, for example in the event of a prolonged power failure or at a first start-up of the table 1, the applied voltage will som act as a signal for calibration of the table 1. The motors 15 will then be ordered to move downwards until the zero position, which is registered of the zero position sensor 18 is reached. In the event of shorter power outages, however, the power supply will be maintained by the accumulators 9.

The invention can be further modified within the scope of the appended claims.

Claims (11)

10 15 20 25 527 764 11 PATENT REQUIREMENTS Raise adjustable piece of furniture (1) comprising at least two legs (2, 3) of variable length, a drive motor (15) belonging to the respective legs (2, 3) and means (10, 11) for producing and transmitting an input signal ( 3) indicating whether the furniture is to move upwards, downwards or to a calibration position, characterized in that one of the legs, called the prairie leg (2), is arranged to receive the input signal (33) and perform a movement accordingly , that a communication line (12) is arranged for exchanging information signals about the movements of the primary leg (2) and the other legs (3) and that the other legs (3) are arranged to iron their own positions with the movement of the primary leg (2) and to provide a corresponding movement in each leg (3). Height-adjustable furniture according to claim 1, characterized in that the communication line (12) is a bus, which is arranged for the transmission of the signals up, down and waiting. Raise adjustable furniture according to claim 1 or 2, characterized in that the legs each comprise rotary sensors (24, 25) for producing the information sigrals. Height-adjustable piece of furniture (1) according to one of Claims 1 to 3, characterized in that the legs (2, 3) each comprise a zero position sensor (18) for sensing a position to which the actual length of the respective legs (2, 3) is related. . Height-adjustable piece of furniture (1) according to one of Claims 1 to 4, characterized in that the legs (2, 3) each comprise a microprocessor (21). 10 15 20 25 527 764 12 Height-adjustable furniture according to one of Claims 1 to 5, characterized in that the legs (2, 3) each comprise an accumulator (9). A method for raising and lowering height-adjustable furniture (1) with at least two height-adjustable legs (2, 3), comprising the steps of: making a choice whether the furniture (1) is to be raised, lowered or moved to a calibration position and that a selection corresponding to the signal (33) is generated, characterized in that the signal (33) is applied to one of the legs, which is a primary leg (2); causing the primary leg (2) to perform a movement corresponding to the received signal (3 3); that in the primary leg (2) an information signal is generated with information about the movement performed; that the information signal is passed to the other legs (3); that in each other leg (3) an iron movement is made between the position of this leg (3) and the position of the primary leg (2); and that each other leg (3) is caused to move until it has assumed the same position as the primary leg (2). A method according to claim 7, characterized in that the receiving bone (3) except the primary bone (2) is caused to send a waiting signal to the primary bone (2) when the difference between the position of the bone (3) and the information signal exceeds a predetermined value, and that the primary bone ( 2) is thereby caused to stop its movement until the difference is again less than the predetermined value. Method according to claim 7 or 8, characterized in that the information signal comprises a series of pulses (27) corresponding to the longitudinal change of the primary leg (2) traveled at any given moment. 10. lO. Method according to one of Claims 7 to 9, characterized in that the information signal is transmitted on different lines (28, 29) depending on whether the movement is upward or downward. 527 764 13 Method according to claim 8, characterized in that the waiting signal is transmitted on a separate line (32).