JP2002330841A - Office chair - Google Patents

Abstract

(57) [Summary] [Problem] To move a seat or a backrest without using the weight of a seated person. SOLUTION: An office chair 1 having structures such as a seat 3 and a backrest 2 movable with respect to a leg 15 is provided with an electric actuator 4 for moving the structures 2 and 3.
For example, a synchro mechanism 51 for interlocking the seat 3 and the backrest 2 is provided, and the actuator 4 moves the seat 3 and the backrest 2 simultaneously by operating the synchro mechanism 51.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an office chair used for general office work in a room such as an office. More specifically, the present invention relates to an office chair provided with a structure such as a seat, a backrest, or an armrest or a headrest, which is movable with respect to a leg. In the present specification, the office chair is not limited to a chair used for general office use, and includes, for example, a learning chair and a chair with casters.

[0002]

2. Description of the Related Art Office chairs of this type include, for example, a type in which a seat and a backrest are simultaneously inclined by a synchronization mechanism, and a type in which a seat and a backrest are separately tilted, moved back and forth, or moved up and down. A reaction mechanism and a lock mechanism are usually attached to the synchro mechanism and the elevating mechanism of the seat and the backrest. When the lock mechanism is released, the seat and the backrest are located at the initial positions by the urging force of the reaction force means.

On the other hand, there is also an office chair provided with a seat that can be moved back and forth with respect to a seat receiving member, and provided with a back and forth movement mechanism that can lock the seat at an arbitrary position. Generally, the back-and-forth movement mechanism of the seat is not provided with a reaction force means such as a coil spring.
The seat can be easily moved in any of the front and rear directions.

[0004]

However, in the above-described chair, since the movement of the seat or the backrest is performed by using the weight of the occupant or the biasing force of the coil spring, it is difficult to finely adjust the position. . In addition, for example, in the tilting operation of the backrest or the raising / lowering operation of the seat, the seated person must moderately weight,
Operability is not good.

On the other hand, if the seat does not have a reaction mechanism, such as a back-and-forth movement mechanism, it is necessary to release the lock mechanism of the seat, perform manual positioning, and lock the seat again with the lock mechanism. Therefore, the work is complicated and the operability is poor.

Accordingly, an object of the present invention is to provide an office chair capable of moving a seat or a backrest without using the weight of a seated person.

[0007]

SUMMARY OF THE INVENTION In order to achieve the above object, the invention according to claim 1 is to move a structure in an office chair having a structure such as a seat or a backrest movable with respect to a leg. An electric drive device for driving the motor is provided.

Accordingly, since the structure is moved by the electric driving device, there is no need to use the weight of the occupant to move the structure, and the driving device is operated only by operating an electric switch or detecting a sensor. Will be able to operate. Therefore, the operability for moving the structure can be improved.

According to a second aspect of the present invention, there is provided the office chair according to the first aspect, wherein the structure comprises a seat and a backrest, and a synchronization mechanism for interlocking the seat and the backrest. By operating the synchronization mechanism, the seat and the backrest are simultaneously moved.
Therefore, since the seat and the backrest are linked by the synchronization mechanism, the seat and the backrest can be simultaneously moved only by operating one switch or detecting the sensor.

[0010] Further, the invention according to claim 3 is based on claim 1.
In the office chair described above, the structure includes a seat and a backrest, a synchro mechanism for interlocking the seat and the backrest, and a seat back-and-forth movement mechanism for supporting the seat so as to be able to move back and forth with respect to the synchro mechanism. The driving device is constituted by a synchronizing driving device for moving the seat and the backrest at the same time by operating the synchronizing mechanism, and a seat back-and-forth moving driving device for moving the seat back and forth by operating the seat back-and-forth moving mechanism. Therefore, the seat back-and-forth movement mechanism is electrically operated, so that the seat can be moved back and forth only by operating the switch or detecting the sensor.

According to a fourth aspect of the present invention, there is provided the office chair according to the first aspect, wherein the driving device moves the structure back and forth. According to a fifth aspect of the present invention, in the office chair according to the first aspect, the driving device inclines the structure. Further, according to a sixth aspect of the present invention, in the office chair according to the first aspect, the driving device raises and lowers the structure. Therefore, the structure can be moved only by operating the switch or detecting the sensor.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail based on an embodiment shown in the drawings. 1 and 2 show a first embodiment of an office chair 1 according to the present invention. The office chair 1 includes a seat 3 and a backrest 2 that are movable with respect to the legs 15.
And the like. And this office chair 1
Is provided with an electric driving device 4 for moving the structures 2 and 3. Therefore, it is not necessary to use the weight of the occupant to move the structures 2 and 3 and the structures 2 and 3 are moved only by operating the electric switch 50 for operating the driving device 4 or detecting the sensor. Therefore, the operability for moving the structures 2 and 3 can be improved.

The structures are a seat 3 and a backrest 2. The office chair 1 is provided with a synchronizing mechanism 51 for interlocking the seat 3 and the backrest 2. Further, the drive device 4 moves the seat 3 and the backrest 2 at the same time by operating the synchronization mechanism 51. For this reason, the seat 3 and the backrest 2 are
1, the seat 3 and the backrest 2 can be simultaneously moved only by operating one switch 50 or detecting a sensor.

The synchronizing mechanism 51 includes a support lever 20 rotatably provided on the seat receiving member 10,
And a seat support pipe 52 for rotatably fixing the seat 3. The front end of the support lever 20 is
Is attached by a left-right rotation shaft 53 near the center portion of the. The backrest 2 is attached to the rear end of the support lever 20 via a back support rod 54. Further, a contact portion 20a is formed in a part of the support lever 20. On the other hand, the stopper 10a in which the contact portion 20a contacts the seat receiving member 10 to determine the lower limit of the range of movement of the support lever 20
Are formed. Therefore, the support lever 20 swings in a range until the contact portion 20a contacts the stopper 10a.

The front end of the seat 3 is attached to the seat receiving member 10 so as to be rotatable about a left-right axis (not shown). The rear of the seat 3 is supported from below by a seat support pipe 52. Thus, the swing of the support lever 20 causes the seat 3 to swing about the axis of the front end so as to move up and down the rear part. The backrest 2 includes a backrest body and a pressing member 55 attached to the backrest body so as to sandwich the back support rod 54 between the backrest body. Therefore, the backrest 2 is provided so as to sandwich the back support rod 54 between the backrest main body and the pressing member 55 and to be able to move up and down with respect to the back support rod 54.

The driving device 4 can be expanded and contracted and fixed at an arbitrary length. Further, the drive device 4 having a fixed length is elastically variable in the direction of expansion and contraction under external force. The driving device 4 includes a support lever 2
0 and the seat receiving member 10. Drive 4
The support lever 20 and the seat receiving member 10 are connected so as to form a triangle. Therefore, when the drive device 4 is operated to expand and contract, the support lever 20 swings with respect to the seat receiving member 10, and the backrest 2 and the seat 3 also swing in conjunction with each other. When the length of the driving device 4 is fixed, the support lever 20 is elastically supported by the seat receiving member 10, so that the backrest 2 and the seat 3 are also elastically supported by the driving device 4. Therefore, the backrest 2 and the seat 3 have a cushioning property, so that the sitting comfort is good.

The driving device 4 is connected to a driver (not shown) for controlling the operation. Here, as the driving device 4 having the above-described functions, for example, an LSA series manufactured by Kawada Kogyo Co., Ltd., and as an driver, an LSAD series manufactured by Kawada Kogyo Co., Ltd. can be mentioned. In this case, by applying an external force to the driving device 4, the external force is detected by the driving device 4 and the driver, and the driving device 4 can be controlled corresponding to the external force.

Thus, the driving device 4 and the driver can be used as an operation sensor. For example, if the driver is set to operate the driving device 4 in the same direction as the external force when the driving device 4 receives an external force of a certain threshold or more, the seated person can apply a large force to the backrest 2. The backrest 2 can automatically fall down when leaned. Conversely, the backrest 2 can be set to rise when a slight external force is applied to push the backrest 2 forward from behind. By setting like this,
Since the backrest 2 can be depressed only with the weight of the back and can be raised with a light force, it is not necessary to use the weight of the seated person, and the operability can be improved.

Further, a power supply for driving the driving device 4 and the driver is provided on the leg 15 of the office chair 1.
It is preferable to use a small and rechargeable battery as a power source. Thus, the size of the office chair 1 can be suppressed, and a cord for supplying power from the outside becomes unnecessary, so that it is possible to suppress the cord from hindering the movement of the office chair 1. In this office chair 1, a power supply consisting of a battery is mounted on the office chair 1 in order to allow the chair to freely move. It may be used in combination with a rechargeable secondary battery.

An operation switch for operating the driving device 4 is connected to the driver. This operation switch is attached, for example, to the front end of the armrest. According to this, since the operation switch is provided at the position where the finger is naturally located when the forearm is placed on the armrest, the operability can be improved.

When using the office chair 1 of this embodiment, the occupant operates the operation switch 50 on the armrest to extend and contract the drive unit 4. Thereby, the inclination angles of the backrest 2 and the seat 3 can be changed. Further, when the seated person leans strongly on the backrest 2, it is detected by the driving device 4 and the driver, and the driving device 4 is contracted and tilted in the direction in which the backrest 2 falls. Further, when the backrest 2 is lightly pushed from the rear to the front, it is detected by the driving device 4 and the driver, and the driving device 4 is extended to move in a direction in which the backrest 2 rises.

In the present embodiment, the load applied to the backrest 2 by the driving device 4 and the driver is detected. However, the present invention is not limited to this. 4 may perform only the expansion / contraction operation, and a pressure sensor for detecting an external force or a limit switch for detecting that the backrest 2 is tilted by a predetermined amount or more by a load may be separately provided. In this case, when an external force having a magnitude equal to or larger than the threshold is detected by a pressure sensor, a limit switch, or the like, the driving device 4 is operated to move the backrest 2 and the seat 3. According to this, since the general-purpose drive device 4 and the pressure sensor can be used, the cost increase of the office chair 1 can be suppressed low.

Further, in the above-described embodiment, the driving device 4 which can be elastically expanded and contracted by an external force after fixing the length is adopted. However, the present invention is not limited to this. A drive device 4 that cannot be used may be employed. In this case, if the length of the driving device 4 is fixed, the positions of the backrest 2 and the seat 3 can be completely fixed.

Further, in the above-described embodiment, the driving device 4
The apparatus itself has an elastic deformation mechanism, but the invention is not limited to this. The drive apparatus 4 whose length is completely fixed is employed, and the drive apparatus 4 and any one of the support lever 20 and the seat receiving member 10 are used. By interposing an elastic body such as a coil spring,
When the length of the driving device 4 is fixed, the backrest 2 and the seat 3
May be elastically supported by an elastic body. Also in this case, the backrest 2 and the seat 3 can have cushioning properties.

Further, in the above-described embodiment, the driving device 4
Although two sensors, the operation switch and the operation switch, are used to supply the operation signal to the driving device 4, the operation signal can be supplied to the driving device 4 if at least one of the sensor and the operation switch is provided.

In the above-described embodiment, the seat 3 swings only around the front end. However, the present invention is not limited to this. A mechanism may be provided. In this case, a swing member that swings around the front end portion is provided to the seat receiving member 10 and the seat 3 is provided to be able to move back and forth with respect to the swing member. Therefore, the seat 3 can swing with the swinging member, and since the seat 3 can be moved back and forth to adjust the depth, the sitting comfort can be finely adjusted.

Further, the driving device at this time includes a synchronizing driving device 4 for operating the synchronizing mechanism 51 to move the seat 3 and the backrest 2 simultaneously, and a seat for operating the seat back-and-forth moving mechanism to move the seat 3 back and forth. A drive device for forward and backward movement is provided. However, the back-and-forth movement of the seat 3 is not limited to being performed by the electric drive device, and may be performed manually.

Next, FIGS. 3 to 6 show a second embodiment of the office chair 1 of the present invention. The office chair 1 has structures such as a seat 3 and a backrest 2 that can move with respect to the legs 15, and an electric driving device 4 that moves the structures 2 and 3.
This is the same as the first embodiment in that the first embodiment is provided.

In this embodiment, the backrest 2 and the seat 3 are moved from the upright position to the reclining position (or vice versa).
Center C _B of the respective rotational movement backrest 2 and the seat 3 when _tilted, C _S, and forward of the upper a and backrest 2 from the seat 3 in a range not far from office chairs 1, preferably the seat 3 Is set nearer to the front and above the seat 3, more preferably, at a position that the user does not want to move in the working posture, for example, at or near a working point when a seated person works.

The center C _S of the rotational movement of the backrest 2 and the seat 3,
To set the C _B and above a front portion of the seat 3,
Since the rotation direction of the backrest 2 and the seat 3 is always the same direction and downward in the swing range, no tilt point or dead point occurs in the swing range, and the tilting operation by the driving device 4 is easily performed. In addition, an excessive inclination is not given at the time of the reclining posture, and the occupant is less likely to feel unstable. In addition, since the rising of the front edge of the seat 3 in the reclining posture is reliably suppressed, the back of the thigh is not pressed. In particular, the center C of the rotational movement of the seat 3
_{If s} is arranged so as to be forward of the front edge of the seat 3 in the reclining posture, it is possible to reliably prevent the front edge of the seat 3 from rising.

Furthermore, the backrest 2 and the rotational movement of the center C _S of the seat _3, when setting the position or the vicinity thereof does not want to move the C _B, for example, in office chairs 1, at least one of the rotational movement of the center C _S or C _B, when a seat occupant is set in the vicinity of the desk hand or arm at the time of work, it is possible to locking without changing the position of the hand on the operating point for example on the keyboard. The working posture is mainly an upright posture, but is not particularly limited to this, and a working posture as required is taken.

The office chair 1 has a slider 58 slidably attached to the seat receiving member 10 and a seat frame 56 supporting the seat 3 and fixed to the slider 58.
And a back frame 57 that supports the backrest 2 and is attached to the seat frame 56 and the slider 58.

Between the seat receiving member 10 and the slider 58,
First and second slider mechanisms 22 and 23 are provided. The first slider mechanism 22 is provided between the front end portion of the slider 58 and the seat receiving member 10 and supports the slider 58 at one point to guide the movement in the forward and downward and rearward and upward directions. The slider mechanism 22 includes the seat receiving member 10.
Slot (or slot) provided near the front end of the
2a, and a pin 22b formed on the slider 58 and slidably fitted in the elongated hole 22a. The second slider mechanism 23 is provided between the rear end of the slider 58 and the seat receiving member 10, supports the slider 58 at one point, and guides the movement in the forward and downward and rearward and upward directions. It is. The slider mechanism 23 has a long hole (or long groove) 23 provided at a position near the rear end of the seat receiving member 10.
a, and a pin 23b formed in the slider 58 and slidably fitted in the elongated hole 23a.

The shape and inclination angle of each of the elongated holes 22a, 23a, the center C _S of the rotational movement when the seat 3 moves is set to be in a position that does not want to move at the time of working posture. Thus, with the the slider 58 is moved back and forth, the seat 3 and the backrest 2 is moved to rotate about the point C _S, a C _B. That is, when the office chair 1 is in the reclining state, the seat 3 moves so as to come forward while sinking the rear part.

The lower front end of the back frame 57 is the seat frame 5.
6, and a portion slightly behind and slightly above it is attached to the slider 58 via a reaction force means 59. The reaction force means 59 is, for example, a compression coil spring, and urges the backrest 2 in a direction to return to the upright position. For this reason, the backrest 2 can be locked to the seat 3.

The driving device 4 includes a motor 60, two parallel screw shafts 61 rotated by the motor 60, and a screw shaft 6 screwed to the screw shaft 61 and rotated by the screw shaft 61.
And a sliding member 62 that moves along 1. The screw shaft 61 is connected to the elongated hole 23a of the second slider mechanism 23.
It is provided along. The sliding member 62 is a pin 2
3b. Therefore, when the screw shaft 61 is rotated by the drive of the motor 60, the sliding member 62 slides, and the pin 23b is moved in the elongated hole 23a. This allows
The positions of the backrest 2 and the seat 3 are changed.

The office chair 1 has a motor 60.
A driver 63 for controlling the driving of the motor 60, a power cord 64 for connecting the motor 60 and the driver 63 to a power supply, and an operation switch 50 for turning on and off the driving of the motor 60 are provided. The power cord 64 is connected to a commercial power supply. In this case, the battery becomes unnecessary, so that the weight and cost of the office chair 1 itself can be reduced.
Note that, as in the first embodiment, the battery is connected to a battery or a solar cell mounted on the office chair 1 without using a commercial power supply, or a combination of a solar battery or a commercial power supply and a rechargeable secondary battery is used. May be used.

Since the driving device 4 uses the screw shaft 61 and the sliding member 62 screwed to the screw shaft 61, the backrest 2 and the seat 3 can be fixed at arbitrary positions. Further, it is preferable to attach the operation switch 50 to the front end of the armrest. In this case, the operability can be improved because the operation switch 50 is located at the position where the finger is naturally located when the forearm is placed on the armrest.

Next, FIG. 7 shows a third embodiment of the office chair 1 of the present invention. The office chair 1 has structures such as a seat 3 and a backrest 2 that can be moved with respect to a leg 15 and an electric driving device 4 that moves the structures 2 and 3. This is the same as the first and second embodiments. The mechanism for moving the seat 3 by the driving device 4 is the same as in the second embodiment.

In this embodiment, a back sensor 65 for detecting a load applied to the backrest 2 is provided between the seat frame 56 and the back frame 57. This back sensor 65
Is provided between the reaction force means 59 of the backrest 2 and the back frame 57 and is connected to the driver 63. Therefore, the load acting on the backrest 2 is always detected by the driver 63. As the back sensor 65, a pressure sensor that detects a reaction force from the reaction force means 59 can be used, or a sensor that detects displacement between the seat frame 56 and the back frame 57 can be used.

When the load acting on the backrest 2 is greater than a certain threshold, the driver 63 is set to operate the driving device 4 in the same direction as the direction in which the load acts. Thereby, when the seated person leans against the backrest 2 with a large force, the backrest 2 can automatically fall down. Conversely, the backrest 2 is set to rise when a slight external force is applied to push the backrest 2 forward from behind. With this setting, the backrest 2 can be depressed only with the weight of the back and can be raised with a small force, so that it is not necessary to use the weight of the seated person, and the operability can be improved.

In this embodiment, an operation switch for operating the driving device 4 is omitted. For this reason,
The number of parts can be minimized. However, the second
Needless to say, an operation switch may be provided as in the embodiment.

Next, FIG. 8 shows a fourth embodiment of the office chair 1 of the present invention. The office chair 1 has structures such as a seat 3 and a backrest 2 that can be moved with respect to a leg 15 and an electric driving device 4 that moves the structures 2 and 3. This is the same as the first to third embodiments. Also,
The mechanism for moving the seat 3 by the driving device 4 is the same as in the second and third embodiments.

In this embodiment, a back drive device 66 for tilting the backrest 2 with respect to the seat 3 is provided between the seat frame 56 and the back frame 57. The back drive device 66 includes a motor 67 rotatably attached to a back frame 57, a screw shaft 68 integrated with a rotation shaft of the motor 67, and a screw shaft 68 screwed to the screw shaft 68 to rotate the screw shaft 68. A nut 69 that moves along the screw shaft 68, and an arm 70 fixed to the nut 69 and rotatably attached to the seat frame 56. Therefore, when the screw shaft 68 is rotated by the drive of the motor 67, the distance between the nut 69 and the arm 70 changes, so that the backrest 2
Of the seat 3 with respect to the seat 3 is changed. The motor 67 is connected to the driver 63.

In this embodiment, an operation switch 50 for turning on and off the driving of the two driving devices 4 and 66 is provided. When the office chair 1 is in the reclining state, the seat 4 is moved by the driving device 4 so as to come out forward while sinking the rear portion, and at the same time, the back driving device 6 is moved.
6, the backrest 2 is moved so as to tilt backward. Thereby, the seat 3 and the backrest 2 can be interlocked with each other by operating one operation switch 50 while keeping the sitting comfort of the office chair 1 optimal, so that the seat 3 and the backrest 2 can be separately operated. The operability can be improved as compared with the case of performing.

In this embodiment, one operation switch 5
0, the seat 3 and the backrest 2 are interlocked. However, the present invention is not limited to this. For example, only the seat 3 is moved by operating the operation switch 50 and the load acting on the backrest 2 is reduced. A sensor for detection may be provided to move the backrest 2 when a load exceeding the threshold is applied.

Further, the seat 3 and the backrest 2 are linked by operating one operation switch 50. However, the present invention is not limited to this. Two operation switches are provided to separate the seat 3 and the backrest 2. May be operated.

The above embodiments are merely examples of preferred embodiments of the present invention, but the present invention is not limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. For example, in each of the above-described embodiments, the structure is the backrest 2 and the seat 3, but the structure is not limited thereto, and may be an armrest, a headrest, a footrest, or the like. In any case, the operability can be improved by moving the electric motor in comparison with the manual operation.

In each of the above-described embodiments, the structure is moved back and forth or inclined. However, the structure is not limited to this, and the structure may be moved up and down. For example, as shown in FIG. 9 and FIG. 10, an electric driving device 4 that expands and contracts is provided at the elevating part of the leg 15 so that the seat 3 and the backrest 2 are raised and lowered as a whole. Thereby, the height of the office chair 1 can be adjusted electrically. In these cases, the seat 3 can be lowered when the front end of the seat 3 is tilted to elevate, for example, so that it is possible to prevent the front end of the seat 3 from pressing the back side of the thigh. Also,
When the front end of the seat 3 is tilted so as to descend, the seat 3
Can be raised, so that even if the distance between the front end of the seat 3 and the floor is kept constant and the knee is bent, the thigh can be prevented from floating from the seat surface.

Here, in the office chair 1 shown in FIG. 9, an LSA series manufactured by Kawada Kogyo Co., Ltd. is adopted as the drive device 4 and an LSA manufactured by Kawada Kogyo Co., Ltd. as a driver.
The SAD series is used. Therefore, the driving device 4
Can be provided with a spring property, so that the sitting comfort can be improved as compared with a case where a driving device without the spring property is used. In the office chair 1, the main body 4b of the driving device 4 is fixed to the leg 15 side, and a seat receiving member is attached to the distal end of the rod 4a that protrudes and disappears from the main body 4b. For this reason, it is not necessary to raise and lower the main body 4b of the driving device 4 when the seat 3 and the backrest 2 are raised and lowered, so that the weight of the members to be raised and lowered can be minimized and the driving device 4 can be prevented from being enlarged.

Further, in the office chair 1 shown in FIG. 10, the main body 4b of the driving device 4 is fixed to the seat receiving member, and the tip of the rod 4a which comes and goes in the main body 4b is attached to the leg 15 side. For this reason, since the main body 4b of the driving device 4 can be arranged near the battery, the operation switch, and the like, the twisting of the wiring cord when the office chair 1 is rotated around the legs can be prevented.

[0052]

As is apparent from the above description, according to the office chair of the first aspect, since the structure is moved by the electric driving device, the operability for moving the structure is improved. be able to.

According to the office chair of the second aspect, the seat and the backrest are linked by the synchronizing mechanism, so that the structure can be moved while maintaining the positional relationship between the seat and the backrest optimally. Operability can be improved.

Further, according to the office chair of the third aspect, the seat can be moved back and forth to adjust the depth of the chair, so that the sitting comfort can be finely adjusted.

On the other hand, according to the office chair of the present invention, the structure can be variously moved only by operating the switch or detecting the sensor, so that the operability can be improved.

[Brief description of the drawings]

FIG. 1 is a side view showing a main part of a first embodiment of an office chair according to the present invention.

FIG. 2 is a perspective view showing a main part of the first embodiment of the office chair.

FIG. 3 is a rear perspective view showing a second embodiment of an office chair.

FIG. 4 is a front perspective view showing a second embodiment of an office chair.

FIG. 5 is a side view showing an upright state of a second embodiment of an office chair.

FIG. 6 is a side view showing the reclining state of the second embodiment of the office chair.

FIG. 7 is a rear perspective view showing a third embodiment of an office chair.

FIG. 8 is a perspective view from the rear showing a fourth embodiment of an office chair.

9A and 9B are side views showing another embodiment of the office chair, wherein FIG. 9A is a state in which the seat and the backrest are located at the lowest position, and FIG. 9B is a state in which the seat and the backrest are located at the uppermost position.

FIGS. 10A and 10B are side views showing another embodiment of the office chair, wherein FIG. 10A is a state in which the seat and the backrest are located at the lowest position, and FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 office chair 2 backrest (structure) 3 seat (structure) 4 drive device 15 legs 51 synchro mechanism 66 back drive device

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Kenji Nakahara 137 Miyatamura, Kamiina-gun, Nagano Prefecture F-term in Takano Corporation Technical Department 3B084 GA02 3B091 AA04 AA05 AB04 AC01 AD01 AD02 GA00

Claims (6)

[Claims] 1. An office chair having a structure such as a seat and a backrest movable with respect to a leg, the office chair comprising an electric driving device for moving the structure. 2. The structure comprises a seat and a backrest, and a synchronizing mechanism for interlocking the seat and the backrest. The driving device operates the synchronizing mechanism to cause the seat and the backrest to operate. 2. The office chair according to claim 1, wherein the chairs are simultaneously moved. 3. The structure includes a seat and a backrest, a synchro mechanism for interlocking the seat and the backrest, and a seat back-and-forth movement mechanism for supporting the seat so as to be able to move back and forth with respect to the synchro mechanism. A driving device for synchronizing, which activates the synchronizing mechanism to simultaneously move the seat and the backrest, and a driving device for seat longitudinal movement, which operates the seat longitudinal movement mechanism to move the seat back and forth. 2. The office chair according to claim 1, comprising: 4. The office chair according to claim 1, wherein the driving device moves the structure back and forth. 5. The office chair according to claim 1, wherein the driving device tilts the structure. 6. The office chair according to claim 1, wherein the driving device raises and lowers the structure.