JP3106360B2 - Automatic tilting chair - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic seat tilting chair provided with a seat that reciprocates in tilting motion. The pelvis mainly including the lumbar back part by repeatedly changing the hip joint angle (trunk thigh angle) and waist sacral angle (Sensakisaki angle) related to the sitting posture continuously by repeatedly tilting forward and backward. The present invention relates to an automatic seat tilting chair that relieves continuous tension of surrounding muscles and moves a contact area with the seat to reduce pain in the buttocks and thighs and swelling of the lower limbs. In addition, "seat", "seat surface", and "seat part" are used interchangeably.

[0002]

2. Description of the Related Art Conventionally, in order to solve problems such as low back pain caused by a sitting posture of an office chair, various recommendations for chair design have been made. However, recent studies have shown that sitting in the same position all day, even in an optimally designed chair, can cause lower back and hip pain and lower leg swelling. The reasons for the fixed sitting postures 1) to 3) below have been pointed out as the reason.

1) Muscle fatigue and circulatory disorders due to muscle contraction When the same sitting posture is continued, a continuous muscle contraction occurs in a group of muscles holding the posture (e.g., erector spine muscle, iliopsoas muscle, lower limb muscle group). Causes muscle fatigue and circulatory disturbance in the site. This causes low back pain and swelling of the lower limbs.

2) Nutritional disorders of the intervertebral disc (cartilage) Since the intervertebral disc has no blood vessels, metabolism is performed by diffusion of nutrients from surrounding blood vessels. This diffusion is facilitated by changes in the intervertebral disc pressure due to changes in posture.
If the same sitting posture is continued, this diffusion is inhibited, causing a nutritional disorder of the disc, which causes a disc disorder and low back pain.

[0005] 3) Circulation disorder due to pressure on the seat surface If the same sitting posture is continued, pressure is applied to a contact portion with the seat surface (the ischial tuberosity or the rear surface of the thigh), causing a circulation disorder. This causes pain in the buttocks and thighs and swelling of the lower limbs.

[0006] Under these circumstances, a chair that can be tilted by human power (hereinafter referred to as a human-powered tilting chair) has been known as a chair applied as an office chair. This includes A)
There are a rocking chair type in which the entire chair tilts, and a seat tilting type in which only B) the seat surface tilts. Note that chairs in which only the backrest tilts are excluded because they have different technical fields.

The rocking chair type has been mainly used for rest. Kick the floor with your feet or use your upper body to tilt. When you sit deep and use the back,
It is fixed at a fixed tilt center and cannot be changed according to the work. The tilt direction is only the sagittal plane and does not tilt in the lateral direction. The tilt range can be adjusted by the degree of movement of the foot or upper body, but fine control is difficult. When tilting with upper body movement without using legs in a standard chair, the tilting speed is 16 °
/1.6 seconds (tilt frequency is 1 cycle / 1.6 seconds (0.63 Hertz)), which is quite fast, causing rapid eye movement and causing eyestrain and work problems. Also, because it moves by hand,
In highly constrained operations, tilting is reduced. There are no casters, which hinder rotation and movement. Therefore, it is not suitable for work use. One cycle means a tilt repetition process. (Described later in Examples)

[0008] In the seat tilting type, the seat is mounted on a tilt axis in the center of the lower portion of the seat surface, and has a movable range of -5 ° (backward tilt) to + 20 ° (forward tilt). Tilts due to hip position and trunk flexion. The center of tilt, range, and speed are adjustable, but fine control is difficult. The tilting direction is only the sagittal plane, and does not tilt in the lateral direction. On the contrary, because of the tilting function, the support of the seat surface is unstable, so that the muscle tension increases and the work is hindered. Since the work is performed manually, the tilting is reduced in highly restrictive work.

[0009]

However, according to the investigation on the inclination of the seat surface of the chair at the time of office work, according to the above-mentioned conventional tilting chair, the following problems as office chairs are still solved. No, a technical solution is required.

The preferred inclination of the seat surface differs depending on the operation. In general office work such as writing work, reading a document, and searching for a document, a posture in which the trunk is inclined forward, that is, a seat surface inclined forward is preferred. However, in the type work and the VDT work, a posture tilted backward, that is, a seat surface tilted slightly backward is preferred. Such a difference is attributed to the arrangement of the work target. In other words, in the latter operation, the type paper and the screen are not horizontal to the surface of the desk, but are inclined toward the worker, so that a slightly inclined posture is preferred. As described above, the preferred posture, that is, the inclination of the seat surface, changes depending on the content of the work and the state of the target object. In order to solve this problem, it is necessary that the inclination of the center of tilt (the center of motion in repeated tilting) with respect to the horizontal of the seat can be freely adjusted by work. In addition, the seat surface on which the tilt center is set may be referred to as a set tilt base surface. FIG. 9 shows the tilt center (set tilt base plane) defined here.

[0011] The inclination of the seat surface increases over time. In general office work, the forward leaning posture of the seat surface increases as the sitting position elapses. (Survey showed that during a 48-minute sitting position, the forward tilt of the seat increased from 8.5 ° to 9.2 ° on average.) To solve this problem, the tilt center can be automatically adjusted over time, ie It is necessary to be able to continuously shift from the initially set inclination of the seat surface to the horizontal (initial setting tilt base surface) to the tilt set after a lapse of a predetermined time (final setting tilt base surface).

Increase in the range and frequency of tilting of the seat over time. In general office work, the range and frequency of tilting of the seat surface increase with the lapse of time in the sitting position. (In the survey, large tilts of 2 ° or more in 48 minutes increased from an average of 40 to 88 times per hour, and small tilts of 2 ° or less in an average of 514 hours / hour)
Increased from 621 times to 621 times. This reflects a natural requirement to avoid a restrained working posture and is considered a reaction to reduce fatigue due to the same posture. In order to solve this problem, it is necessary that the movement can be adjusted so that the tilt range and the tilt frequency increase with time.

In a highly restrictive operation such as a type, a tilt range and a frequency are reduced. In the type work, the tilting range and frequency are reduced as compared with the general office work, and the myoelectric potential of the psoas muscle increases. It is considered that the type work has a strong restraint on the posture, so that the tilting property is reduced. It is considered that the more restrictive the work, the more the inclination is necessary for the prevention of low back pain and the like. In order to solve this problem, a mechanical (forced) automatic tilt function is required instead of manual power.

Control of the tilting speed. If the tilting speed is high, it is necessary to quickly adjust the line of sight and posture due to the tilting, which causes eye strain and troubles in work. In order to solve this problem, it is necessary to appropriately control the tilting speed.

Seat stability. In office work, there are relatively many precision works, and stability of the seat surface is required. However, the manual tilting chair lacks stability because it is tilted by its own action. In order to solve this problem, a mechanical (forced) automatic tilt function is required instead of manual power.

The present invention has been made based on such knowledge, and has an automatic seat tilting chair having dynamic characteristics necessary for solving the above-mentioned problem, that is, a seat having a seat which tilts forward and backward repeatedly. An automatic seat tilting chair is provided.

More specifically, the tilting mechanism of the seat is changed to a mechanical type, and the seat (plane) is mechanically tilted forward and backward repeatedly, and the hip joint angle (trunk thigh angle) and the lumbosacral angle related to the sitting posture are determined. By continuously changing the (Sensaki angle), the mobility is increased, the continuous tension of the muscle around the pelvis, mainly the lumbar region, is relaxed, and the contact area with the seat surface is moved. An object of the present invention is to provide an automatic seat tilting chair capable of reducing pain in the buttocks and thighs and swelling of the lower limbs. In addition,
The use is typically for office chairs, but is not limited thereto. For example, application to a working chair (working chair), a wheelchair for the disabled, a vehicle seat, a marine seat, an aircraft seat, and other long-time sitting chairs or seats is considered.

[0018]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is directed to a machine which supports a seat, which is provided separately and independently from a backrest, so as to be able to tilt forward and backward between a leg member and a machine. It has a forward / backward tilt repetition mechanism that automatically changes the tilting direction within a predetermined angle range and changes the motion while continuously changing the tilting angle by continuously driving and tilting, and tilting the seat. It is an improvement of the automatic seat tilting chair that increases the mobility of the sitting posture by repetitive movement and relaxes the continuous tension of the muscles around the pelvis, mainly the lower back, and the reciprocating mechanism for tilting back and forth,
It is provided on the lower surface of the seat, and comprises a front-rear tilting operation means for mechanically driving and tilting the seat, and for continuously changing the inclination angle, the front-rear tilting operation means includes:
A crank arm and a speed reducer element are mainly constituted, a front-rear tilting shaft and a crank arm fixed shaft are mounted on the lower surface of a seat portion, and the crank arm is mounted on a frame supported by brackets from leg members, and the speed reducer is mounted. In addition to controlling the drive of the motor with a speed reducer via the motor, the motion is changed by the eccentric rotation of the crank arm.

An automatic seat tilting chair modified from the above-described front-back tilt repeating mechanism, wherein the front-back tilt repeating mechanism is provided on a lower surface of a seat portion, and the seat portion is mechanically driven to tilt.
And, it comprises a forward and backward tilting moving means for continuously changing its tilt angle, and the forward and backward tilting moving means is mainly composed of a screw and a spur gear element, and is provided on the lower surface of the seat portion. Attach tilt axis and screw fixed axis,
A screw is mounted on the frame supported by the bracket from the leg member, the drive of the motor with a speed reducer is controlled via a spur gear, and the motion is changed by alternately switching the rotation direction of the screw. Is what you do.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention is directed to a seat which is fixed to a leg member, and a seat which is separated and independent from the backrest and is pivotally supported between the leg member so as to be able to tilt forward and backward. And a forward and backward tilting movement means for mechanically driving and tilting the seat, and continuously changing the tilt angle, provided on the lower surface of the seat, Along with a forward / backward tilt repeating mechanism comprising a forward / backward motion converting means for automatically alternating the tilting direction within a predetermined angle range,
The forward / backward tilting movement means is mainly composed of a crank arm and a speed reducer element, and a forward / backward tilting shaft and a crank arm fixed shaft are attached to a lower surface of a seat portion, and the crank arm is mounted on a frame supported by brackets from leg members. It is mounted and drives a motor with a speed reducer via the speed reducer. The forward / backward motion conversion means is a drive control of the motor with the speed reducer.

Further, the forward / backward tilting repeating mechanism mainly comprising the crank arm and the speed reducer element is modified to one mainly comprising a screw and a spur gear element, and a forward / backward tilting shaft and a screw fixing shaft are provided on the lower surface of the seat portion. And a screw is mounted on the frame supported by the bracket from the leg member, and a motor with a speed reducer is driven via a spur gear. The back-and-forth movement conversion means is for switching and instructing the rotation direction of the screw alternately by setting a timer.

Further, in each of the above-mentioned configurations, the inclination angle of the seat portion in the front-rear direction can be adjusted within a range (tilt range) of 20 degrees forward to 5 degrees rearward with respect to the horizontal of the seat surface.

In this way, the seat is automatically tilted to the sagittal plane (front and rear) by power drive, and the tilt center (tilt setting base plane), tilt range, tilt speed (and frequency) are adjusted according to the working characteristics and the fatigue state. adjust. Here, the backrest is not interlocked, only the seat surface is tilted, and the hip joint angle (trunk thigh angle) and the waist sacral angle (Sensaki angle) related to the sitting posture are continuously changed to enhance the mobility. I have to.

By utilizing this dynamic characteristic, for example, when used as an office chair, lower back pain, buttocks pain, and swelling of the lower limb due to sitting work can be reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the accompanying drawings.

(Embodiment 1) FIG. 1 shows an (a) front view and (b) a left side view of an automatic seat tilting chair provided with a forward / backward tilt repeating mechanism mainly comprising a crank arm and a speed reducer element of the present invention. FIG. In addition, the left side view is a front view related to the sitting posture.

FIG. 2 is a plan view explanatory view showing the front-back tilt mechanism,
3 is a front view explanatory view, and FIG. 4 is a left side view explanatory view. Here, the backrest and a part of the leg members are not shown.

As shown in the figure, in the automatic seat tilting chair (X) of the present embodiment, the backrest (2) is fixed to the leg member (1), and the seat (3) is connected to the backrest (2). Is separated and independent, and pivotally supported so as to be able to tilt forward and backward with the leg member (1),
The seat portion (3) is caused to repeatedly tilt and move forward and backward. [Fig. 1]

The back-and-forth tilting repetition mechanism (4) is provided on the lower surface of the seat portion (3), supports the seating surface (311) so as to be tiltable back and forth, mechanically drives to tilt, and Forward / backward movement changing means for automatically changing the tilting direction of the seating surface (311) within a predetermined angle range, while having forward / backward tilting movement means (41) for continuously changing the tilting angle. Having. (It is not shown because it is controlled by driving the forward and backward tilting movement means (41).) [FIGS. 2, 3, and 4]

The tilting movement means (41) in the forward and backward tilting repetition mechanism (4) includes a crank arm (411) and a reduction gear element (4).
12,413), and the front and rear tilting shaft (5) and the crank arm fixed shaft (6) are provided on the lower surface of the seat (3).
Attach the crank arm (411) from the leg member (1) to the frame (8) supported by the bracket (7),
The motor with reduction gear (413) is driven via the reduction gear (412). [Fig. 2, Fig. 3, Fig. 4]

The forward / backward motion converting means is a drive control of the motor with a reduction gear (413), and is performed by eccentrically rotating the crank arm (411) about the horizontal position of the forward / backward tilt shaft (5). The horizontal position is detected by a sensor (414) on the lower surface of the seat (3). [Fig. 2, Fig. 3]

Here, the inclination angle of the seat portion (3) for forward and backward tilting can be adjusted within a range of 20 ° forward tilt to 5 ° rearward tilt with respect to the horizontal of the seat surface (311). Is the knob (81
1) Loosen and move the seat (3), adjust the angle while looking at the scale plate (812), and tighten the knob (811) to fix it.

The tilting speed can be adjusted within a range from a maximum of 20 ° / 5 seconds to a minimum of 20 ° / 5 minutes. In addition,
In terms of the tilting frequency, the cycle is from a maximum of 1 cycle / 5 seconds to a minimum of 1 cycle / 5 minutes, with one cycle of ± 5 ° (tilting repetition stroke 20 ° [degree]) with respect to the tilting center.

As shown in the setting example relating to the tilting of the seat surface in FIG. 9, the forward tilt angle of the seat surface with respect to the horizontal plane is θ. According to the present embodiment, first, the tilt center (0 ° or θ) is arbitrarily set, and the forward / backward tilt range is ± 1 ° with respect to the tilt center.
(1 cycle of tilting repetition process 4 ° [degree] 1 cycle) to ± 5 °
(Tilting repetition stroke is set to 20 ° [degree] for one cycle), the speed (rotational speed) is uniquely determined, and the power is turned on to start. Adjustment of this forward / backward tilt range is performed by the reduction gear (4
This is done by moving the slider (415) attached to the output shaft of (12).

As described above, in the present embodiment, the adjustment of the tilt angle and the forward / backward tilt range are performed manually, but drive control may be performed using an angle sensor (for example, a rotary encoder). . In this case, it is possible to change (shift) the tilt center and the tilt range from the beginning to the end of the tilt repetition motion by initially setting and / or finally setting the tilt center (set tilt base plane). Needless to say. In other words, the control of the drive system (tilting operation moving means 41) of the above-described forward / backward tilting repetition mechanism (4) can be integrated and automated in one controller box, but a known means configuration may be used, and illustration thereof is omitted. did.

(Embodiment 2) FIG. 5 shows (a) a front view and (b) a left side view of an automatic seat tilting chair provided with a forward and backward tilting repetition mechanism mainly comprising a screw and a spur gear element of the present invention. FIG.

FIG. 6 is a plan view explanatory view showing the front-back tilt mechanism.
7 is a front view explanatory view, and FIG. 8 is a right side view explanatory view. Here, the backrest and a part of the leg members are not shown.

As shown in the figure, the automatic seat tilting chair (Y) of the present embodiment comprises a crank arm (411) and a speed reducer element (4) in the forward / backward tilting repetition mechanism (4) described in the first embodiment.
12,413) is changed to a tilting movement means (42) mainly composed of a screw (421,422) and a spur gear element (423,424), and a seat (3)
Tilting shaft (5) and screw fixed shaft (6) on the lower surface
Attach the screws (421, 422) from the leg member (1) to the frame (8) supported by the bracket (7),
The motor with reduction gear (425) is driven via the spur gears (423, 424). [Fig. 5, Fig. 6, Fig. 7, Fig. 8]

The means for converting back and forth motion is a screw (421, 42
2) Alternating control in the rotation direction, which is performed by instructing switching between forward and reverse rotation by setting a timer. (It is not shown because it is driven by the forward / backward tilting movement means (42).) The horizontal position is detected by a sensor (426) on the lower surface of the seat (3). [Fig. 6, Fig. 7]

Here, the tilt angle, the forward / backward tilt range, and the controller box relating to the forward / backward tilting of the seat (3) may be the same as those in the above-described first embodiment, and a description thereof will be omitted.

[0041]

The present invention has the above-described configuration, and according to the present invention, the following advantageous effects can be obtained.

(1) The seat can be automatically tilted in the sagittal plane (front and back) and / or in the lateral direction (right and left) by power drive, and the tilt center, tilt range, tilt speed (and frequency) are determined by the work characteristics and It can be adjusted according to the fatigue situation.

(2) Using the dynamic characteristics described above,
By applying as described above, it is possible to prevent or reduce back pain, buttocks pain, swelling of the lower limbs, eye strain and the like associated with the sitting position.

The backrest is not interlocked, only the seat surface is tilted, and the hip joint angle (trunk thigh angle), lumbosacral angle (sensui cape angle) and / or trunk flexion angle relating to the sitting posture are continuously changed. By increasing the mobility, the continuous tension of the muscles around the pelvis, mainly the lower back, is alleviated, and the buttock and thigh pain and lower limb Reduce swelling. Also, to promote the diffusion of nutrients by changing the internal pressure of the disc. (Preventive or alleviating effect on back pain)

In a normal sitting position, the seating, backrest and floorboard are 65%, 10% and 25% of body weight, respectively.
Supporting%. By tilting the sagittal plane (front and back), the body weight distribution tilts from the seat surface to the backrest or lower limb side, relieving sustained pressure on the buttocks and thighs, and pumping action due to contraction of lower limb muscle groups Improves circulation of lower limbs. In addition, by tilting in the lateral direction (left and right), the body weight is alternately shifted to the left and right ischial tuberosity, and continuous compression on the buttocks and thighs is relieved. [Prevention or reduction effect on buttock pain and swelling of lower limbs]

By setting the tilting speed to 20 ° / 5 seconds or less, sudden movement of the line of sight and posture is suppressed, and eyestrain and trouble to work are eliminated. (Prevention or reduction of eye strain and other disorders)

[Brief description of the drawings]

FIG. 1A is a front view and FIG. 1B is a left side view of the automatic tilting chair according to the first embodiment.

FIG. 2 is an explanatory plan view showing the front-rear tilt mechanism.

FIG. 3 is an explanatory view showing the same in a front view.

FIG. 4 is an explanatory diagram viewed from the right side.

FIG. 5A is a front view of the automatic seat tilting chair according to the second embodiment, and FIG.

FIG. 6 is an explanatory plan view showing the front-rear tilt mechanism.

FIG. 7 is a front view explanatory view.

FIG. 8 is an explanatory view of the same side view.

FIG. 9 is an explanatory view showing a tilt center (set tilt base plane).

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Leg member 2 Backrest part 3 Seat part (seat surface) 311 Seat surface 4 Front-back tilting repetition mechanism 41 Front-back tilting movement means 411 Crank arm 412 Reduction gear 413 Motor with reduction gear 414 Sensor 415 Slider 42 Front-back tilting movement means 421 Screw 422 Screw Nut 423 Spur gear 424 Spur gear 425 Motor with reduction gear 426 Sensor 5 Forward and backward tilt shaft 6 Crank arm fixed shaft 66 Screw fixed shaft 7 Bracket 8 Frame 811 Knob 812 Scale plate X Automatic seat tilting chair (crank) Y Automatic seat tilt Chair (screw)

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Masahiro Uto 3-7-5 Ushida Shinmachi, Higashi-ku, Hiroshima-shi, Hiroshima (72) Inventor Stephen Acons 2834 Manhattan, Oregon, Kansas, United States (56) References JP-A-4-4- 9152 (JP, A) JP-A-52-92665 (JP, A) JP-A-4-307004 (JP, A) JP-A-63-143063 (JP, A) Jikken Sho 51-11273 (JP, Y2) J. 43-26756 (JP, Y1) (58) Field surveyed (Int. Cl. ⁷ , DB name) A47C 3/00-9/10

Claims (5)

(57) [Claims] 1. Automatically changing the position of a sitting person's body
Equipped with a seat that swings continuously and continuously, and the seat at least
Also provide means to shake regularly and continuously when a person sits down
In a chair with a swinging seat, it is used as a work chair and detects the power combined with a seat that changes the tilt angle periodically within a set angle range, and the tilt angle
Has a mechanism of power control that performs control output related to motion based on the motion, and makes the seating surface repeatedly tilt and reciprocate mechanically
By changing the hip joint angle and the lumbo-sacral angle of the sitting posture continuously, the mobility of the hip joint and the lumbar pelvis around the pelvis to relieve the continuous tension, Is pivotally supported so that it can be tilted back and forth between the leg member and the separate and independently provided seat portion, and is tilted by mechanical drive, continuously changing its tilt angle, and of the tilting direction within an angular range automatically an automatic seat tilting chair provided with the longitudinal tilting repetition mechanism in alternating movement converter, the front-rear tilting iterative mechanism is provided on the lower surface of the seat portion, the seat portion Is tilted by mechanically driving it, and comprises forward and backward tilting movement means for continuously changing the tilt angle, the front and rearward tilting movement means mainly comprising a crank arm and a speed reducer element. The front and rear tilting shaft and the The arm is fixed to the arm, the crank arm is mounted on the frame supported by the bracket from the leg member, the drive of the motor with the speed reducer is controlled via the speed reducer, and the motion is changed by the eccentric rotation of the crank arm. Characteristic automatic seat tilting chair. 2. Automatically changing the position of a sitting person's body
Equipped with a seat that swings continuously and continuously, and the seat at least
Also provide means to shake regularly and continuously when a person sits down
In a chair with a swinging seat, it is used as a work chair and detects the power combined with a seat that changes the tilt angle periodically within a set angle range, and the tilt angle
Has a mechanism of power control that performs control output related to motion based on the motion, and makes the seating surface repeatedly tilt and reciprocate mechanically
By changing the hip joint angle and the lumbo-sacral angle of the sitting posture continuously, the mobility of the hip member and the muscles around the pelvis, mainly the lumbar back, are alleviated. The fixed backrest, the backrest is separate and independent, and a seat is pivotally supported between the leg members so as to be able to tilt forward and backward. The seat is provided on the lower surface of the seat, and the seat is mechanically mounted. Forward and backward tilting movement means for driving and tilting and continuously changing the tilt angle, and forward and backward movement for automatically alternating the tilting direction of the seat within a predetermined angle range. An automatic seat tilting chair provided with a forward / backward tilting repetition mechanism including a conversion means , wherein the forward / backward tilting movement means mainly includes a crank arm and a speed reducer element, and a forward / backward tilting shaft is provided on a lower surface of the seat portion. And the crank arm fixed shaft, and An automatic seat, wherein a crank arm is mounted on a racket-supported frame and a motor with a speed reducer is driven via a speed reducer, and the longitudinal movement conversion means is drive control of the motor with a speed reducer. Surface tilting chair. 3. A seat, which is provided separately and independently from the backrest, is pivotally supported between the leg members so as to be able to tilt forward and backward, and is mechanically driven to be tilted. It has a forward / backward tilt repeating mechanism that automatically alternates the tilting direction within a predetermined angle range and changes the motion within the specified angle range. In an automatic seat tilting chair designed to relieve the continuous tension of the muscles around the pelvis, a front-back tilt repeating mechanism is provided on the lower surface of the seat, and the seat is mechanically driven to tilt, And, it comprises a forward and backward tilting moving means for continuously changing its tilt angle, and the forward and backward tilting moving means is mainly composed of a screw and a spur gear element, and is provided on the lower surface of the seat portion. Attach the tilt axis and the screw fixed axis, and The automatic mounting characterized in that the screw is mounted on the frame supported by the bracket, the drive of the motor with the speed reducer is controlled via the spur gear, and the motion is changed by alternating the traveling direction or the rotating direction of the screw. Tilting chair. 4. A backrest portion fixed to a leg member, a seat portion separated and independent from the backrest portion, and pivotally supported between the leg member so as to be able to tilt forward and backward, and provided on a lower surface of the seat portion. And
Forward and backward tilting operation moving means for mechanically driving and tilting the seat, and for continuously changing the tilt angle;
A back-and-forth tilting repetition mechanism comprising a fore-and-aft motion conversion means for automatically alternating the tilting direction of the seat within a predetermined angle range; An automatic seat tilting chair that relieves continuous tension of muscles around the pelvis, mainly comprising: a screw and a spur gear element as a main constituent, and a lower surface of the seat. Attach the screw to the frame supported by the bracket from the leg member, and drive the motor with the reducer through the spur gear. An automatic seat tilting chair characterized in that the rotation direction of a screw is instructed and is alternately controlled. 5. The automatic seat according to claim 1, wherein the inclination angle of the seat portion in the front-back direction is in a range of 20 degrees forward to 5 degrees rearward with respect to the horizontal of the seat surface. Surface tilting chair.