JP2002142899A - Operation lever structure for chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an operation lever structure for a chair, which is functionally equipped with plural operation levers so as to be easily operable without wrong operation. SOLUTION: Two operation levers 60, 61 are pivotally supported coaxially around an axis so as to be extended in mutually reverse directions under the seat 9 of a chair. The operation levers 60, 61 are respectively communicated with controlling mechanisms of mutually different movement parts of the chair.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of an operation lever for operating a control mechanism of various moving parts in a chair.

[0002]

2. Description of the Related Art Recent chairs include a seat and armrest height adjusting mechanism, a backrest reclining mechanism, a seat back-and-forth position adjusting mechanism, and a backrest standing position angle adjusting means.
There are many moving parts such as a maximum back tilt angle adjusting means of the backrest, and a control mechanism for controlling them is linked to one or a plurality of operation levers.

[0003]

As described above, recent chairs, especially high-end chairs, tend to be provided with a large number of operating levers, and it is desirable to provide them so that they can be operated easily without error. It is rare.

SUMMARY OF THE INVENTION [0004] In view of such a demand, an object of the present invention is to provide an operation lever structure in a chair in which a plurality of operation levers are provided so as to be easily operated without fear of erroneous operation and functionally. I have.

[0005]

According to the present invention, the above-mentioned problems are solved as follows. (1) Two operating levers are coaxially supported below the chair seat so as to extend coaxially and in opposite directions about the axis, and each operating lever is provided with a different moving part of the chair. , Respectively.

(2) In the above item (1), the two operation levers are pivotally supported below one side of the seat with a shaft pointing in the left-right direction, and an operation lever extending forward from the shaft and a rearward extending lever. One of the operating levers to be operated is linked to the angle adjusting means for the upright position of the backrest, which is one of the control mechanisms for the moving part, and the other operating lever is connected to the control mechanism for the moving part. It is linked to another one of the means for adjusting the maximum rearward tilt angle of the backrest.

(3) In the above item (1) or (2), each operating lever is provided with a cylindrical portion having the same outer diameter and an operating piece extending eccentrically from an outer peripheral surface thereof. The two cylinders are arranged close to each other in the axial direction, and each operation piece extends toward the cylinder of the other operation lever.

(4) In any one of the above items (1) to (3), one of the operation levers is connected to the cylinder shaft, and the other operation lever is connected to the cylinder with a core shaft inserted through the cylinder shaft. Connect to the part exposed from the shaft.

(5) In the above item (4), the cylindrical shaft and the core shaft are respectively linked to control mechanisms of different moving members.

[0010]

An embodiment of the present invention will be described below with reference to the accompanying drawings. As shown in FIGS. 1 and 2, casters (2) are provided at the distal ends of the support legs (1) extending radially from the center, and the center of the support legs (1) is A pillar (3) is erected, and a support (4) is fixed to the upper end of the pillar (3).

A pair of right and left back rods (6) supporting the backrest (5) are formed on the support base (4) so as to extend rearward and upward in an L-shape in side view.
The front end of the lower part facing forward is pivotally mounted so as to be rotatable around an axis pointing in the left-right direction, and the backrest (5) and the back rod (6) are provided in the support base (4) and will be described later. The elastic reclining mechanism (7) and the tilt range adjusting device (8) allow the tilting range adjusting device (8) to tilt backward from the standing position as shown in FIG. 1 within the range defined by the tilt range adjusting device (8). Has become.

Above the support (4), a seat (9) is provided with a seat (1).
0), the backrest (5) and the back bar (6) are supported so as to move rearward and downward in conjunction with the backward tilt of the backrest. Since the support structure of the seat (9) and its linking mechanism with the backrest are not directly related to the present invention, a detailed description thereof will be omitted.

Armrests (12) are provided on both sides of the seat receiver (10) via support rods (11) extending in the left-right direction.

Next, the details of the elastic reclining mechanism (7) and the tilt range adjusting device (8) provided in the support (4) will be described with reference to FIGS.

The support base (4) has a box shape with an open lower surface,
The rear part is fitted on the upper end of the pillar (3) and is supported on the pillar (3) so as to be slightly inclined forward and upward.

At the front and rear portions of both side walls (4a) of the support base (4), a tapered cylindrical body (13) whose diameter is slightly reduced outward.
(14) is formed integrally.

A pair of left and right cylindrical shafts (16) each forming a hexagonal cylindrical shape is provided in a through hole (15) penetrating through each rear cylindrical body (14) and the side wall (4a) of the support base (4). It is rotatably supported by a pair of inner and outer bushes (17, 18). The outer ends of the left and right cylindrical shafts (16) projecting outward from the cylindrical body (14) are connected to the inner end surface of a laterally truncated cone-shaped receiver (19) formed at the front end of the back rod (6). It is fitted into the formed hexagonal hole (20) and is fastened by a set screw (21).

The inner ends of the left and right cylindrical shafts (16) are separated from each other. A series of elongated torsion bars (22) consisting of multiple leaf springs stacked and bundled in the left and right cylinder shafts (16)
Are loosely fitted, and both ends of the torsion bar (22) are
The receiver (19) of (6) is press-fitted into a rectangular hole (23) formed at the deep end of the hexagonal hole (20) and fastened by a set screw (not shown) as necessary.

In the gap between the inner ends of the left and right cylindrical shafts (16), a forward-facing adjusting plate (24) having a central portion of a torsion bar (22) inserted into a square hole (24) formed in the base end portion. 25) is provided.

A cylindrical portion (27) having a screw hole (26) oriented substantially vertically is fixed to the tip of the adjusting plate (25) facing forward.

The screw hole (26) has a rotating handle (2
An adjusting screw (29) having an upper end (8) is screwed into the upper wall (4b), and an upper end protruding upward from the screw hole (26) is brought into contact with a lower surface of the upper wall (4b) of the support base (4). By adjusting the distance from the torsion bar (22) to the tip of the adjustment plate (25), the amount of initial torsion of the torsion bar (22) when the backrest (5) is located in the upright position is adjusted. ), The biasing force for returning to the standing position can be adjusted.

An angle adjusting means for adjusting the angular position of the adjusting plate (25) about the center axis of the torsion bar (22) is formed by the screw hole (26) and the adjusting screw (29).

Also, the angle adjusting means and the torsion bar
(22), the cylinder shaft (16), the cylinder (14) and the like form an elastic reclining mechanism (7).

A round hole (30) and a U-shaped notch (31) are provided at point-symmetric positions around the square hole (24) in the adjusting plate (25).

On both sides of the base of the adjusting plate (25), there is an insertion hole (32) in the center where a torsion bar (22) passes, and on the outer surface, the inner end of the cylindrical shaft (16) rotates. A pair of synthetic resin bearings (3) having a circular recess (33) that fits freely
4), the boss (35) protruding from each inner surface, the adjustment plate (25)
Bearing that fits into the round hole (30) and notch (31)
By fitting a projecting shaft (36) projecting from the inner surface of (34) into an engaging hole (37) drilled in the center of the boss (35), the adjusting plate (25)
Are provided so as not to be able to rotate relative to.

The recess (3) of the bearing (34) in the left and right cylindrical shafts (16)
A hexagonal hole (39) provided at the base end (rear end) of a pair of left and right arms (38) facing forward is fitted outside the inner end fitted in 3). A shaft (40) that faces in the left-right direction is penetrated through both ends of the arms (38) so as to protrude to both sides.

As shown in FIGS. 3 to 9, on the right side of the two arms (38) in the support base (4), there are main parts of the maximum back inclination angle adjusting means (41) of the backrest (5). A certain first regulating member (42)
Similarly, on the left side, a second regulating member (44), which is a main component of the angle adjusting means (43) for the upright position (initial position) of the backrest (5), is attached to the upper wall of the support base (4). (4b) and a bottom plate screwed to the lower end of a pair of front and rear bosses (45) hanging from the lower surface
(46) sandwiched from above and below, and each regulating member (42) (44)
A front-rear guide groove (48) formed on the lower surface of the upper wall (4b) of the support base (4) with a front-rear groove (47) formed at the upper end of the base (4).
Are arranged so as to be slidably engaged with each other.

The inner surface of the first restricting member (42) is moved forward, so that the amount of protrusion of the right end of the shaft (40) into the vertical rotation locus gradually increases. (40) and arm
A substantially wedge-shaped contact portion (49) is formed so as to reduce the upward rotation range of (38).

In this example, the contact portion (49) which is inclined forward and upward
Is formed in a stepped shape, and the receiving surface (50) of the shaft (40) in each step is formed in an arc shape close to the outer diameter of the shaft (40).

By forming a lightening hole (51) communicating with the groove (47) from the outer surface on the upper part of the first regulating member (42), an elastic bending piece (52) is formed on the upper part. The hemispherical projections (53) formed on the upper surface of the center are formed on the upper wall (4b) of the support (4).
Each receiving surface (50) is aligned with the shaft (40) by selectively engaging a plurality of recesses (54) provided on the lower surface of one side at the same pitch as the pitch of each receiving surface (50). At a stable position.

A square step (55) is formed at the upper front corner of the outer surface of the first regulating member (42), and an engagement hole ( 56) is drilled.
An inwardly bent portion (57a) at the rear end of a rod (57) facing the front and rear direction for linking with a first operation lever (60) described later is fitted into the engagement hole (56). I have.

A left-right cylindrical shaft (58) is rotatably supported in the left cylindrical body (13) at the front of the support base (4).
A core shaft (59) oriented in the same direction is inserted into the cylindrical shaft (58) so as to be relatively rotatable.

The first and second operation levers (6) are provided at the left ends of the core shaft (59) projecting outward from the cylinder shaft (58) and the cylinder body (13).
0) (61) (61) (60a) (61a) cylindrical parts having the same outer diameter
These are fitted so that they come into contact with each other with the tubular portion (60a) being outside, and the outside tubular portion (60a) is fixed to the core shaft (59) with a set screw (62).

In the first operation lever (60), the cylinder (6)
0a), the operation piece (60b) extends forward from the outer periphery of the operation piece (60b), and the right end of the operation piece (60b) extends in the direction of the cylinder (61a) of the second operation lever (61). ) Is extended by the same length as the length.

In the second operating lever (61), the cylindrical portion (6
The operation piece (61b) extends rearward from the outer periphery of 1a), and the left end of the operation piece (61b) is oriented in the direction of the cylinder (60a) of the first operation lever (60). ) Is extended by the same length as the length.

The core shaft (59) projecting from the right end of the cylindrical shaft (58) is
A shaft hole (63a) formed at the base end of the operating arm (63) facing rearward and upward is fitted into the right end of the extended right end of the side wall (4a) of (4). And are fastened with set screws (64).

The core shaft (59) has a left side surface of the operating arm (63).
By contacting the right side of the bifurcated piece (65) hanging from the lower surface of the upper wall (4b) of the support (4), movement to the left is prevented,
It is retained from the cylinder (13).

The inwardly bent portion (57b) at the front end of the rod (57) is fitted into an engagement hole (63b) formed in the end of the operating arm (63) and extending in the left-right direction. I have.

Thus, by rotating the first operating lever (60) downward, the first operating lever (60), the core shaft (59) and the operating arm (6) are turned.
3) is rotated in the counterclockwise direction in FIG. 6, and the rotation of the operating arm (63) at this time pulls the rod (57) forward, and the first regulating member (42) The projections (53) are
By engaging one by one in step (4), the backrest (5) can be advanced step by step, and the maximum backward tilt angle of the backrest (5) can be limited to a gradually smaller angle.

Conversely, by turning the first operating lever (60) upward, the first regulating member is operated in the reverse manner to the above.
(42) is moved backward step by step, and the maximum backward tilt angle of the backrest (5) can be gradually increased.

The first regulating member (42), rod (57), operating arm (63), core shaft (59), first operating lever (60), etc.
A maximum back tilt angle adjusting means (41) for the backrest (5) is formed.

The inner surface of the second regulating member (44) is moved rearward, so that the amount of protrusion of the left end of the shaft (40) into the vertical rotation locus gradually increases, (40) and arm
A substantially wedge-shaped contact portion (66) is formed so as to reduce the downward rotation range of (38).

In this example, the contact portion (66) inclined rearward and downward is provided.
Of the shaft (40) at each step (6)
7) has an arc shape close to the outer diameter of the shaft (40).

A large-diameter protruding shaft (69) having a horizontal hole (68) extending in the front-rear direction is formed in the rear upper portion and the front lower portion of the outer side surface (left side surface) of the second regulating member (44). And a small-diameter protruding shaft (70) are provided to protrude, respectively.

The rear end of the small projecting shaft (70) has a left bottom plate (4).
6) The front end of the tension coil spring (72) locked on the projection (71) projecting outward from the rear end outside is locked.

The lateral hole (68) of the large-diameter projecting shaft (69) is provided with a biasing force stronger than that of the tension coil spring (72), that is, after the tension coil spring (73) directed in the front-rear direction with a large spring constant. An L-shaped locking portion (73a) formed at the end is inserted and locked.

The front end of the tension coil spring (73) is linked to the second operation lever (61) as described later.

A non-circular fitting formed at the left end of the cylindrical shaft (58) is fitted into a small-diameter cylindrical portion (61c) formed at the right end of the cylindrical portion (61a) of the second operating lever (61). The part (58a) is fitted, and the second operation lever (61) is connected to the cylinder shaft (58) while being prevented from rotating.

At the right end of the cylindrical shaft (58), a spur gear (74) is integrally formed. The spur gear (74) is attached to the upper wall (4b) of the support (4) immediately above. An integral sector gear (77) meshes with a shaft (76) rotatably fitted in a semi-cylindrical bearing recess (75) (see FIG. 8) provided on the lower surface of the shaft.

On the right side of the shaft (76) and the sector gear (77),
The upper end of the operation arm (78) having a substantially semicircular shape in a side view is fixedly formed integrally or integrally formed.

The middle portion of the operating arm (78) has an elastic tongue (7
9) are integrally formed, and when the operating arm (78) is rotated clockwise about the shaft (76) as shown in FIG. 7, the upper part of the operating arm (78) is With the tongue piece (79), the portion of the core shaft (59) immediately after protruding from the right end of the cylindrical shaft (58) is resiliently gripped, and the operating arm (78) does not rotate counterclockwise from that position Like that.

The front end of the tension coil spring (73) is fixed to a pin (80) projecting rightward from the lower end of the operating arm (78).

Thus, when the second operation lever (61) faces rearward and upward, as shown in FIG.
8) is held in a state where the core shaft (59) is elastically gripped, and the second regulating member (44) is located at the front end.

In this state, the shaft (40) and the arm (38) are
Without being hindered by the abutment portion (66) of the second regulating member (44), the shaft (40) can rotate forward and downward to the maximum until it abuts on the upper surface of the bottom plate (46). The backrest (5) is, for example, oriented substantially vertically.

In this state, when the second operation lever (61) is rotated rearward and downward, and is stopped, for example, in an intermediate substantially horizontal state, the second operation lever (61) and the cylinder shaft (58) are The spur gear (7
4) rotates clockwise in FIG. 7, and accordingly, the operating arm (78) is moved together with the sector gear (77) and the shaft (76).
Is rotated in the counterclockwise direction, and the rotation of the pin (80) at that time causes the tension coil spring (73) to be pushed in the loosening direction.

At this time, when the backrest (5) is located at a substantially vertical standing position and the shaft (40) is at the position shown in FIG. 7, the rear end face of the contact portion (66) comes into contact with the front end thereof. The second regulating member (4
4) is prevented from moving backward, and is kept at the position shown in FIG.

Thereafter, when the backrest (5) is tilted backward by the occupant, and the arm (38) and the shaft (40) are turned upward, the second regulating member (44) is not until then. )
Is moved backward to a position where the urging forces of the two tension coil springs (72) and (73) are balanced.

Thereafter, when the backrest (5) is raised,
(40) is a contact portion (66) of the second regulating member (44) moved rearward.
Abuts on the receiving surface (67) in the middle stage, for example, and cannot be further lowered. Therefore, after that, the backrest (5)
Is a position slightly inclined backward from the above-described vertical state.

When the second operating lever (61) is turned to the rear lower position to the maximum, the second restricting member (44) moves the shaft (40) and the arm (38) by the same operation as described above. Waiting for the backrest to pivot upward, it moves to the rear end as shown in FIG. 9, and at this time, the backrest (5) can return only to a position that is considerably inclined backward.

When the second operation lever (61) is rotated upward from a position facing rearward and downward to a desired position, the operation arm (78) is rotated about the shaft (76) in the reverse operation to that described above. , And the front end of the tension coil spring (73) is pulled forward by the pin (80).

However, at this time, if the shaft (40) is in contact with one of the receiving surfaces (67) and the second regulating member (44) is pressed downward, the second regulating member (44) is pressed. Does not move immediately, and waits for the backrest (5) to be tilted backward by the seated occupant, and moves forward to set the standing position of the backrest (5) at a desired angle.

When the second operating lever (61) is turned to the upper limit facing rearward and upward, the operating arm (78) causes the resilient tongue (79) to move the core shaft (59) as shown in FIG. The second restricting member (44) waits until the backrest (5) is once tilted backward, then returns to the front limit, and thereafter returns to the front limit (5). Will be oriented almost vertically.

As described above, after the backrest (5) is slightly inclined backward, the second regulating member (44) is moved to a position where the urging forces of the two tension coil springs (72) and (73) are balanced. Since it is moved, it is possible to prevent each receiving surface (67) of the second regulating member (44) from being worn or damaged.

Further, by using the spur gear (74) and the sector gear (77), which is a kind of spur gear, by appropriately selecting the ratio of the number of teeth thereof, the second operating lever (61) can be adjusted. The rotation stroke and the amount of rotation required by the operation arm (78) can be coordinated.

The second regulating member (44) and the tension coil spring (7
2) (73), working arm (78), sector gear (77), spur gear (74)
The upright position angle adjusting means (43) is formed by the cylinder shaft (58) having the following, the second operating lever (61), and the like, and the backrest is formed by this and the above-described maximum backward tilt angle adjusting means (41). The tilt range adjusting means (8) of (5) is formed. In addition, the maximum back inclination angle adjusting means (41) of the backrest (5) and the angle adjusting means (4
3) also serves as a control mechanism for the moving part of the chair.

The maximum back-tilt angle adjusting means (41) and the angle adjusting means (43) in the standing position restrict the movement range of the shaft (40) from above and below, so that the backrest (5) can be moved to a desired position. It can be completely restrained by the backward inclination angle.

A shaft (82) of an operation lever (81) is pivotally supported in the cylindrical body (13) at the right front of the support base (4), and the shaft (82) is connected to the seat (9).
However, since these configurations are not directly related to the present invention, detailed description is omitted.

As shown in FIG. 10, a pin (83) projecting from a part of the inner end surface of the cylindrical shaft (58) is connected to the shaft of the operating arm (78).
Engage with the vertically oriented long hole (84) provided immediately below (76),
With the rotation of the cylindrical shaft (58), the operating arm (78) is rotated about the shaft (76) via the pin (83) and the long hole (84), and thus the above-described operation is performed. The spur gear (74) and the sector gear (77) can be omitted.

[0069]

According to the present invention, the following effects can be obtained. According to the first aspect of the present invention, the two operation levers are coaxially pivoted and extend in opposite directions with respect to the shaft, so that the number of shafts is reduced,
In addition to simplifying the structure, the two operating levers can be arranged in a narrow space in a confined space, and even if you are holding a hand, you can check which direction the lever is located on the axis. There is no possibility of erroneous operation and operation is easy.

According to the second aspect of the present invention, two operation levers are arranged in front of and behind a left-right axis in association with the rotation of the backrest in the front-rear direction. Since the control mechanism related to the forward and backward directions can be operated, the operation is functional, and the operation lever can be operated by a natural operation.

According to the third aspect of the present invention, the two operation levers are substantially symmetrical with respect to the axis, so that the design is excellent and the operability is good.

According to the fourth aspect of the present invention, each operation lever can be operated independently of each other, and both operation levers can be stably supported.

According to the fifth aspect of the present invention, the linkage between each operation lever and the control mechanism operated by them is
This can be achieved only by the pivot portion. For example, there is a problem that the flexible tube or the like is exposed to the outside as in a conventional linking device using a shutter release-type linking device in which a wire is inserted through a flexible tube. No, it can be easily integrated into a chair.

[Brief description of the drawings]

FIG. 1 is a side view of a chair provided with an embodiment of the present invention.

FIG. 2 is also an exploded perspective view.

FIG. 3 is an exploded perspective view showing the internal structure of the support base.

FIG. 4 is an enlarged cross-sectional plan view taken along the line IV-IV in FIG. 1;

FIG. 5 is a vertical sectional side view taken along line VV of FIG. 4;

FIG. 6 is a vertical sectional side view taken along the line VI-VI of FIG. 4;

FIG. 7 is a vertical sectional side view taken along line VII-VII in FIG. 4;

FIG. 8 is an enlarged vertical sectional front view taken along line VIII-VIII of FIG. 7;

FIG. 9 is a vertical sectional side view similar to FIG. 7, showing another operation state.

FIG. 10 is an enlarged vertical sectional side view of a main part showing a modification of the linking means between the cylinder shaft and the operating arm.

[Explanation of symbols]

 (1) Support leg (2) Caster (3) Pillar (4) Support (4a) Side wall (4b) Upper wall (5) Backrest (6) Back rod (7) Elastic reclining mechanism (8) Adjusting tilt range Device (9) Seat (10) Seat receiver (11) Support rod (12) Armrest (13) (14) Cylindrical body (15) Through hole (16) Cylindrical shaft (17) (18) Bush (19) Receiver (20) Hex hole (21) Set screw (22) Torsion bar (23) Square hole (24) Square hole (25) Adjustment plate (26) Screw hole (27) Tube (28) Rotating handle (29) Adjustment screw (Angle adjusting means) (30) Round hole (31) Notch (32) Insertion hole (33) Recess (34) Bearing (35) Boss (36) Projection shaft (37) Engagement hole (38) Arm (39 ) Hexagonal hole (40) Shaft (41) Maximum backward inclination angle adjusting means (42) First regulating member (43) Angle adjusting means at standing position (44) Second regulating member (45) Boss (46) Bottom plate ( 47) Groove (48) Guide ridge (49) Contact part (50) Receiving surface (51) Lightening hole (52) Elastic bending piece (53) Projection (54) Recess (55) Step (56) Mating hole (57) Rod (57a) (57b) Inwardly bent part (58) Cylindrical shaft (58a) Fitting part (59) Core shaft (60) First operation leverー (61) 2nd operation lever (60a) (61a) Tube section (60b) (61b) Operation piece (61c) Small diameter tube section (62) Set screw (63) Operating arm (63a) Shaft hole (63b) Mating hole (64) Set screw (65) Bifurcated piece (66) Abutting part (67) Bearing surface (68) Side hole (69) Projection shaft (70) Projection shaft (71) Projection (72) (73) Tension coil Spring (73a) Locking part (74) Spur gear (75) Bearing recess (76) Shaft (77) Sector gear (78) Operating arm (79) Elastic tongue (80) Pin (81) Operating lever (82) Shaft ( 83) Pin (84) Slot

Continuation of the front page F term (reference) 3B084 EA03 EB02 GA01 3B091 AA04 AB04 AC07 AD01 3B099 AA02 BA07 CA05 CA20 CA23 CB04 CB06 DA05 DA06

Claims (5)

[Claims] 1. A lower part of a seat of a chair pivotally supported by two operating levers coaxially and extending in opposite directions about said axis, each operating lever being different from each other in the chair. An operating lever structure for a chair, wherein the operating lever structure is linked to a control mechanism of a moving part. 2. An operation lever which pivotally supports both operation levers with a shaft pointing in the left-right direction below one side of the seat, and which extends forward from the shaft or rearward. One of the operating levers is linked to an angle adjusting means for the upright position of the backrest, which is one of the control mechanisms of the moving part, and the other operating lever is connected to the backrest, which is another one of the control mechanisms of the moving part. 2. The operating lever structure for a chair according to claim 1, wherein said operating lever structure is linked to said maximum backward inclination angle adjusting means. 3. An operating lever, comprising: a cylindrical portion having an outer diameter equal to the operating lever;
An operation piece extending in an eccentric direction from the outer peripheral surface thereof, and both cylinders are disposed in proximity to each other in the axial direction, and each operation piece extends in the direction of the cylinder of the other operation lever. The operating lever structure of the chair according to claim 1 or 2, wherein the operating lever structure is provided. 4. The method according to claim 1, wherein one of the operation levers is connected to the cylinder shaft, and the other operation lever is connected to a portion of the core shaft inserted through the cylinder shaft, the portion being exposed from the cylinder shaft. An operation lever structure in the chair described in the crab. 5. The operation lever structure of a chair according to claim 4, wherein the cylinder shaft and the core shaft are respectively linked to control mechanisms of different moving members.