US20050173952A1 - Chair with means for controlling a cursor - Google Patents

Abstract

The invention relates to a chair comprising at least a chassis; and a seat, as well as means suitable for converting chair movements into control signals for controlling a cursor (pointer) on a display screen. In order to prevent RSI complaints, the invention aims at providing an improved chair, which is characterized in that the seat comprises a convex part, which part can be movably accommodated in a corresponding part of the chassis having a complementary concave shape, and in that the means for controlling the cursor are at least in part disposed at the location of the mating area between said convex and concave parts.

Description

• The invention relates to a chair comprising at least a chassis; and a seat, as well as means suitable for converting chair movements into control signals for controlling a cursor (pointer) on a display screen.
• Such a chair is known from U.S. Pat. No. 5,909,208 in the name of Mr Blomdahl, it provides means which converts rotary movement and tilting movement of the chair into control signals, which may be used for controlling a cursor (mouse pointer) on a display screen of, for example, a computer. Said control means are intended to prevent injuries caused by intensive computer use, which injuries are known by the general designation “mouse problem” or RSI (Repetitive Strain Injury).
• RSI or Repetitive Strain Injury is a collective term used for a number of physical complaints in the muscles, tendons and nerves of in particular the arms and the upper part of the body of computer workers. Although in particular the national authorities have recognised the problem of RSI for a number of years and have been taking direct action in the form of giving advice and taking RSI-reducing measures, for example by providing ergonomic aids, the occurrence of RSI and the related physical complaints form an ever increasing problem. The aforesaid patent aims at providing an ergonomic solution so as to reduce or prevent the occurrence of RSI among computer workers and even to provide a cure in those cases where it should occur.
• RSI complaints can roughly be traced back to an ergonomically wrong seating position of the person in the chair in front of the display screen of a computer. A hunched position of the upper part of the body not only leads to an obstruction of the airways and thus to a less optimum uptake of oxygen in the blood, but it also causes the nerves and the blood vessels to the arms (thoracic outlet) to be pinched. These two causes are primary factors that contribute towards an insufficient supply of blood and oxygen to the arms and in particular to the hands by means of which a generally known mouse pointer is controlled.
• Furthermore, a constantly repeated movement of the index finger on one of the control buttons of the mouse pointer leads to an increased friction of the tendons in the tendon sheaths of the hand. Also the pressure of the wrist resting on the supporting surface leads to an increased compression of the tendons and the tendon sheaths, thus increasing the risk of tissue injury. When the mouse pointer is controlled in this starting position, dorsal flexion and ulnar abduction of the wrist take place, which is an ergonomically unfavourable position and which leads to an abnormal strain on the tendons and the tendon sheaths in the wrist joint.
• Another drawback in particular of the aforesaid U.S. Pat. No. 5,909,208 is connected with the chair that is used in said patent, which chair leads to an undesirable and unnecessary strain on the vertebral column and the upper extremities (the neck and the arms) due to the fact that the person remains in the same seating position too long. All in all, the above causes lead to an inadequate transport of blood and oxygen to the arms, as a result of which an ergonomically unacceptable strain is placed in particular on the muscles and the nerves thereof.
• The object of the present invention is precisely to provide a chair which is to prevent all kinds of physical complaints that can be reduced to RSI, which chair does not have the drawbacks of the chair that is known from U.S. Pat. No. 5,909,208.
• In order to accomplish that objective, the chair is according to the invention characterized in that the seat comprises a convex part, which part can be movably accommodated in a corresponding part of the chassis having a complementary concave shape, and in that the means for controlling the cursor are at least in part disposed at the location of the mating area between said convex and concave parts.
• Said construction not only relieves some of the strain on the arm used for operating the mouse, but in addition this construction of the seat and the chassis has a positive influence on the seating position of the person seated on the chair in question, as a result of which in particular the oxygen uptake by the lungs and consequently the supply of blood rich in oxygen to the arms and the upper part of the body is strongly stimulated. On the other hand, the person in question no longer needs to operate the mouse with his arms, so that all kinds of RSI complaints as described above are prevented.
• It should be noted that the terms “convex” and “concave” relate to curved surfaces having one radius as well as to surfaces having a radius which varies along the surface. Consequently, the invention is not limited to convex and concave surfaces having one radius, but it may also extend to curved surfaces having an ellipsoidal shape, a parabolic shape or another curved shape.
• More in particular, according to one embodiment the seat is movable in at least two orthogonal directions relative to the chassis.
• In one embodiment, the seat may comprise an upright ring formed on the convex part of the seat, which ring limits the movement of the seat relative to the chassis to a particular angular range. This furthermore prevents fingers, clothes etc. getting wedged.
• It has become apparent that in order to achieve an effective control of the moue pointer on the display screen, the seat must be movable through an angle of 10°-20° relative to the chassis.
• A smooth and effective movement of the seat on the chassis can be obtained in that the convex part of the seat can be supported on the convex part of the chassis via ball bearings in one embodiment.
• In order to achieve an effective control of the mouse pointer (cursor) on the display screen, the chair may according to the invention be characterized in that the ball bearings form part of the control means.
• Furthermore, said means may be mounted at least in the seat of the chair, and a specific embodiment of the chair is characterized in that said means comprise at least a balance switch or tumbler switch, for example a mercury switch.
• In another embodiment, the control means control the cursor (pointer) on the display screen by remote control. The remote control means may be optical control means or electromagnetic control means.
• On the other hand, the chair according to the invention, which is furthermore fitted with two armrests, may be characterized in that said armrests are provided with means for (un)locking the movable seat relative to the chassis. The hinged joints may be made up of snap hinges. Thus the user can utilise his chair in a quick and effective manner for controlling the cursor on the display screen and, if the computer is not used for a particular period of time, locking the movable seat in position relative to the chassis, so that the chair are can also be used as an ordinary chair in this position.
• It has become apparent that in order to achieve an ergonomic seating position, which is desirable with a view to preventing RSI complaints, the convex part of the seat preferably forms part of a fictitious sphere, whose centre is located between the shoulder blades of a person seated on the chair.
• It has been established by experiment that the radius R of the fictitious sphere ranges from 40-120 cm, preferably it is 75 cm.
• The invention will be explained in more detail hereinafter with reference to a drawing, in which:
• FIGS. 1A-1C show a first embodiment of an ergonomic chair according to the invention (rear side view);
• FIGS. 2A-2C show the embodiment of the ergonomic chair ofFIGS. 1A-1C (side view);
• FIG. 3 shows another embodiment of an ergonomic chair according to the invention; and
• FIG. 4 shows yet another embodiment of an ergonomic chair according to the invention.
• InFIGS. 1A-1C and2A-2C an embodiment of an ergonomic chair according to the invention is shown in rear views and in side view, respectively.
• The chair is schematically represented and indicated by numeral1. The chair comprises at least atchassis2 and aseat3, on which a person4 (schematically shown) is seated. InFIGS. 1A-1C and2A-2C, only thevertebral column4aand the head of the person are schematically shown. The chair comprises means (schematically represented by the rectangle indicated at7), which means are connected to a suitable connector (not shown) of acomputer5 via suitable signal lines. Since themeans7 function to convert movements of the chair intocontrol signals8 for controlling the cursor (mouse pointer)6 on thedisplay screen5, the connector of thecomputer5, to which the control means7 are connected, may be a well-known COM port or PS/1 connector, for example, which is specifically intended for connecting a mouse pointer device.
• According to the invention theseat3 comprises aconvex part3a,which can be movably accommodated in acorresponding part2aof thechassis2 having a complementary concave shape. More in particular, said convex and said concave part of theseat3 and saidchassis2, respectively, are geared to each other in such a manner that theseat3 can move in at least two orthogonal directions relative to thechassis2. The angle through which the seat can move relative to the chassis preferably ranges from 10°-20° (established by experiment).
• The radius of movement of the seat is limited to this range by mechanical means, for example—as shown inFIG. 3—by means of anupright ring3b.Saidring3bis formed on the convexpart3aof theseat3 and extends circumferentially. Thering3bforms a stop for limiting the maximum movement of theseat3 relative to thechassis2. In addition to that, thering3bfunctions as a protective device to prevent the occupant's clothes and fingers from getting wedged between theseat3 and thechassis2.
• In one embodiment, which is shown inFIGS. 1A-1C andFIGS. 2A-2C, the convexpart3aof theseat3 can be movably accommodated in the convexpart2aof thechassis2 viaball bearings5. Saidball bearings5 are present at the location of the mating area between the convex part of theseat3 and the concave part of thechassis2. AsFIGS. 1A-1C andFIGS. 2A-2C show, the ball bearings, at least one of said ball bearings, forms part of the control means7. To this end theball bearing5 is provided with suitable detecting means or sensors, which convert the rotary movement of theball bearing5 into suitable control signals via aconnection7a,which control signals are subsequently used by the control means7 for controlling the mouse cursor (pointer)6 on the display screen5avia theconnection8.
• In another embodiment, which is shown inFIGS. 1A-1C andFIGS. 2A-2C, the control means7 furthermore comprises one or more switches9a-9bmounted in theseat3 of the chair1.
• Movements to the left and to the right can be detected by means of thebalance switch9aand be converted by the control means7 into suitable control signals for moving thecursor6 to the left and to the right, respectively, on the display screen. Likewise, movements to the rear and to the front of theseat3 can be detected by means of thebalance switch9b(FIGS. 2A-2C) and be converted by the control means7 intosuitable control signals8 for moving the mouse cursor down and up, respectively, on the display screen5a.To this end, both thebalance switch9aand thebalance switch9bare connected to the control means7 by means of suitable cables (not shown).
• Said movements can also be converted by theball bearing5, of course, which bearing is connected to the control means7 by means of thesignal wire7a.
• In another embodiment, on the other hand, the control means7 control the cursor (pointer)6 on the display screen5ain a contactless manner. The contactless control means may be optical control means, in which case one or more light-emitting elements, for example LEDs, which co-operate with light-receiving sensors, are mounted at the location of themating area2a-3abetween theconcave part2aand theconvex part3a.The movement of the light-emitting elements and the light-receiving sensors relative to each other caused by the movement of theseat3 relative to thechassis2 is converted into a change in the position of thecursor6 on the display screen5a.
• The control means7 may also be electromagnetic control means, comprising one or more electromagnetic coils that cooperate with magnets. Movement of a magnet with respect to an electromagnetic coil will lead to an electrical signal according to the principle of electromagnetic induction, on the basis of which thecursor6 is positioned on the display screen5a.
• The curvature of theconvex part3aof theseat3 forms part of a fictitious sphere, whose centre is preferably located between the shoulder blades of theperson4 present on theseat3. The radius R of said fictitious sphere may range from 40-120 cm, preferably it is 70 cm. All this as shown inFIGS. 1A-1C and2A-2C, respectively.
• FIG. 4 shows a supportingsurface11, for example a desktop, from above. Present behind thedesktop11 is thechair2 according to the invention, which is provided witharmrests10aand10b,which, in accordance with the invention, can be moved reciprocatingly (see the double arrows inFIG. 4) for (un)locking the seat relative to the chassis.
• According to the invention, the mouse pointer is controlled by the chair rather than by the usual mouse. In this embodiment, the well-known mouse buttons arelarge control buttons13aand30bplaced beside thekeyboard12, with thebutton13aperforming the function of “left-hand mouse button” and thebutton13bperforming the function of “right-hand mouse button”. Depending on the physical possibilities of the user (he may be left-handed or right-handed or be handicapped on the left or on the right, and consequently be immobile on that side), the mouse buttons may be placed on the left (13a-13b) or on the right (13a′-13b′). The large control buttons only require a low coordinating capacity of the user (which is favourable if the user should have a handicap) and do not place a strain on the wrist joint, the tendons and the tendon sheaths as described above, since the buttons can be controlled with a clenched fist or hand.
• It will be understood that RSI complaints can be prevented with this design of an ergonomic chair, the more so because the head and the shoulders of theperson4 do not move during any of the movements of theseat3 as a result of the convex shape of theseat3. This enables the user not only to view the display screen5amore at ease, but in addition the vertebral column and in particular the shoulders of the user are not strained unnecessarily, which might lead to RSI complaints in the shoulders, the arms and/or the hands.
• In addition to that, such a chair is very suitable for use by handicapped persons, since it is usually easier for persons who have a handicap to move the mouse pointer via the pelvis or the (lower) back. This is certainly the case with persons who have a hand or arm handicap, since higher coordinative skills are required in particular of the hand, which skills are not available due to handicap of the hand or the arm.
• In addition to that, such a chair may be very suitable for playing computer games and video games, because the perception of the game can be significantly enhanced during play if the game can be played by choosing a variable angle of inclination. Think of space travel/flight simulation games, car racing games, skiing games, surfing games etc. etc. in this connection.

Claims (20)

1. A chair comprising at least a chassis; and a seat, and a controller for converting chair movements into control signals for controlling a cursor on a display screen, wherein the seat comprises a convex part that can be movably accommodated in a corresponding part of the chassis having a complementary concave shape, and the controller is at least in part disposed proximate a mating area between the convex and concave parts.

2. A chair according toclaim 1, wherein the seat can move in at least two orthogonal directions relative to the chassis.

3. A chair according toclaim 1, wherein the seat comprises an upright ring formed on the convex part of the seat, which ring limits movement of the seat relative to the chassis to an angular range.

4. A chair according toclaim 3, wherein the seat can move through an angle of 10°-20° relative to the chassis.

5. A chair according toclaim 1, comprising ball bearings for supporting the convex part of the seat can be supported on the convex part of the chassis.

6. A chair according toclaim 5, wherein the ball bearings form part of the controller.

7. A chair according toclaim 1, wherein the controller is at least partially mounted in the seat.

8. A chair according toclaim 1, wherein the controller includes at least one of a balance switch or tumbler switch.

9. A chair according toclaim 1, wherein the controller controls the cursor on the display screen in a contactless manner.

10. A chair according toclaim 9, wherein the controller includes an optical controller for controlling the cursor.

11. A chair according toclaim 9, wherein the controller includes an electromagnetic controller for controlling the cursor.

12. A chair according toclaim 1, comprising at least one armrest provided with means for locking the seat relative to the chassis.

13. A chair according toclaim 12, wherein the locking means includes snap hinges.

14. A chair according toclaim 1, wherein the convex part of the seat forms part of a fictitious sphere having a center arranged to be located between the shoulder blades of a person seated on the chair.

15. A chair according toclaim 14, wherein a radius R of the fictitious sphere ranges from 40-120 cm.

16. A chair according toclaim 2, wherein the seat comprises an upright ring formed on the convex part of the seat, which ring limits movement of the seat relative to the chassis to an angular range.

17. A chair according toclaim 2, wherein the controller is at least partially mounted in the seat.

18. A chair according toclaim 17, wherein the controller includes at least one of a balance switch or tumbler switch.

19. A chair according toclaim 7, wherein the controller includes at least one of a balance switch or tumbler switch.

20. A chair according toclaim 2, wherein the controller controls the cursor on the display screen in a contactless manner.

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