JP4133072B2 - Tilt device such as backrest in chair - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a backrest and seat tilting device for a chair, and more particularly to a biasing force adjusting device for returning and rotating such as a backrest.
[0002]
[Prior art]
For example, in Japanese Utility Model Publication No. 56-19886, which is filed by the present applicant, a torsion bar is used as an urging means for allowing the backrest and the seat to tilt and returning them to their original positions, and its initial twisting force is indicated. A chair provided with an adjusting device for adjusting is disclosed.
[0003]
[Problems to be solved by the invention]
In the above-described conventional adjusting device, since only the initial twisting force of the torsion bar is adjusted, the adjustable range is narrow and the urging force cannot be changed greatly.
[0004]
In view of the above-mentioned problems of the prior art, the present invention can change the urging force of the urging means significantly compared with the conventional one, and the structure is simple and enables a compact design. An object of the present invention is to provide a tilting device such as a backrest in a chair.
[0005]
[Means for Solving the Problems]
According to the present invention, the above problem is solved as follows.
(1) In a tilting device such as a backrest in a chair in which the backrest or seat can be tilted against the biasing force of the return biasing means, the biasing means includes a plurality of unit biasing means. And a switching means for selectively switching so as to enable or disable transmission of the urging force of each unit urging means to the backrest or the seat .
[0006]
(2) In the above item (1), each unit urging means includes a core member that rotates around a central axis integrally with a support rod that supports the backrest or the seat so that the seat can be tilted. A concentric core, a part of which is in contact with a support or switching means that supports the support rod, thereby being prevented from rotating, and filled between the core material and the outer cylinder, The core material is provided with an elastic body that is elastically deformed by rotating around the central axis with respect to the outer cylinder and applies a return turning force to the core material.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
1-10 show a chair comprising one embodiment of the present invention.
[0009]
As shown in FIGS. 1 and 2, the chair includes a leg body (3) having five radial rods (2) each having a caster (1) provided at the tip. In the center of the leg (3), a telescopic leg column (4) provided with a gas spring (not shown) is erected, and at the upper end of the leg column (4), the rear part of the support base (5) Is fixed.
[0010]
The support base (5) has a substantially hollow box shape with an open bottom surface, and the opening on the bottom surface is covered with a removable cover (6).
[0011]
Inside the support base (5), there are urging means (9) (see FIG. 3) for returning the backrest (7) and the seat (8), which will be described later, and switching means (10) for the urging force (FIG. 5). However, as will be described in detail later, the schematic configuration of the backrest and seat tilting device (A) will be described first.
[0012]
A hexagonal columnar shaft (11) facing in the left-right direction is passed through the middle portion of the support base (5) in the front-rear direction so as to be rotatable about its central axis.
A pair of left and right backrests that are substantially L-shaped in a side view supporting the backrest (7) are attached to both ends of the shaft (11) projecting left and right from both side walls (5a) and (5a) of the support base (5). A cylindrical portion (12a) (12a) facing the left-right direction provided at the front end of the support rod (12) (12) is fixedly fitted, and the backrest (7) and the backrest support rod (12) (12) are The shaft (11) and the shaft (11) can be tilted rearward and downward about the shaft (11).
(13) is a headrest provided at the upper end of the backrest (7), and (14) is an armrest provided so as to stand in the middle of the lower part facing the front of the left and right backrest support ridges (12). is there.
[0013]
In the middle part between the cylinder part (12a) and the armrest (14) in the left and right backrest support rods (12), an upward seat support rod (15) is integrally provided. The upper end of (15) is connected to the inner surface of the rear end of the pair of left and right guide rails (16) facing in the front-rear direction with a shaft (17) facing in the left-right direction.
[0014]
The front parts and rear parts of the left and right guide rails (16), (16) are connected to each other with lateral ribs (18) facing in the left-right direction, and are also connected to the outer surfaces of the front ends of both guide rails (16). The upper ends of a pair of left and right support links (19), (19) facing substantially up and down are connected with a shaft (20) facing in the left-right direction.
[0015]
The lower ends of the left and right support links (19) and (19) are located outside the outwardly facing cylindrical portions (21) and (21) provided at the front portions of both side walls (5a) and (5a) of the support base (5). 2 torsion coil springs (23) (see FIG. 5) pivoted around one shaft (22) facing left and right and provided in each cylinder part (21), respectively, in the counterclockwise direction in FIG. It is energized.
An operation lever (24) for adjusting the urging force of the urging means (9) is fixedly fitted to the end of the shaft (22) outside the left support link (19).
[0016]
The left and right guide rails (16) and (16) have a pair of left and right movable rails facing the front and rear, with short leg pieces (25) and (25) fixed to the lower surface of the seat (8). (26) (26) is mounted so that the position can be adjusted in the front-rear direction. Note that the longitudinal position adjustment mechanism of the seat (8) is not directly related to the present invention and will not be described in detail.
[0017]
Thus, the back support rod (12), the seat support rod (15) integral therewith, the support link (19), the torsion coil spring (23), and the return (provided below) provided inside the support base (5). The urging means (9), the urging force switching means (10), and the like form a backrest and seat tilting device (A), and the backrest (7) and the backrest support ridge (12 ) (12) is tilted rearward and downward about the axis (11), the back support rod (12) (12) and the seat support rod (15) (15) integrated with the back tilt at that time, The rear part of the seat (8) is moved rearward and downward, and in conjunction with this, the front part of the seat (8) is also connected to the left and right support links (19) and (19) by the torsion coil springs (23) and (23). By tilting backward against the urging force, it can be moved slightly rearward and downward.
In this example, the left and right torsion coil springs (23) and (23) are auxiliary to the return biasing means (9) provided inside the support base (5).
[0018]
As shown in FIG. 3, the urging means (9) provided in the support base (5) is composed of a plurality (three in this example) of unit urging means (27), (28) and (29). Each unit urging means (27) (28) (29) is a substantially cylindrical core member provided with a hexagonal hole (30) in the center of which the above hexagonal columnar shaft (11) is fitted so as not to be relatively rotatable. (31) and the core material (31) are substantially concentric with each other, and a protrusion (32) projecting from the outer peripheral surface comes into contact with the support base (5) or the switching means (10). 5) Filled between the outer cylinder (33) that is prevented from rotating with respect to the outer cylinder (33) and the core material (31) and the outer cylinder (33). And a cylindrical elastic body (34) made of rubber or a soft synthetic resin material that is elastically deformed by rotating around the central axis and imparts a restoring force to the core material (31). ing.
[0019]
The central unit biasing means (28) is designed to have a larger biasing force by making the axial length longer than the left and right unit biasing means (27) (29), and The left unit urging means (27) is elastic so that the elastic coefficient of its elastic body (34) is larger than that of the elastic body (34) in the other unit urging means (28) (29). By making the material of the body (34) different from that of the other unit urging means (28) and (29), the urging force is minimized.
Therefore, in this example, the biasing force is set to gradually increase in the order of the left unit biasing means (27), the right unit biasing means (29), and the central unit biasing means (28). It is.
[0020]
The protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is always on the stop piece (35) hanging from the lower surface of the front center of the upper wall (5b) of the support base (5). They are in contact (see FIG. 6).
[0021]
A hexagonal hole (36) is cut in the center between the outermost unit urging means (27) (29) and both side walls (5a) (5a) of the support base (5). A pair of left and right discs (38) and (38) provided with a downwardly projecting piece (37) at the bottom are arranged so that their hexagonal holes (36) are fitted to the shaft (11) so that they cannot be rotated relative to each other. It is installed.
[0022]
The upper part of the right disc (38) projects upward through a long hole (39) facing the front-rear direction formed on the right side of the upper wall (5b) of the support base (5), and the inner surface A sectoral sector gear (41) having a fan-shaped side view formed with radial teeth (40) is continuously provided.
[0023]
The sector gear (41) is provided with a central unit biasing means (28) on the backrest (7) even when the backrest (7) is stopped at the most upright position (hereinafter referred to as the initial position). It has a function for applying a force (initial twisting force) and a function for locking the backrest (7) at an arbitrary rearward tilt position.
[0024]
That is, from the state where the protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is in contact with the stop piece (35), the sector gear (41) together with the shaft (11) in FIG. While rotating clockwise by a predetermined initial twist angle, the rear end of the stop plate (42) is brought into contact with the front edge of the sector gear (41) to support the stop plate (42). 5) With the set screw (43) fixed to the upper surface of the upper wall (5b), the shaft (11) is applied with the initial twisting force of the central unit biasing means (28). ) Can be kept counterclockwise in FIG.
[0025]
Further, in this state, the cylindrical portions (12a) and (12a) of the backrest support rods (12) and (12), which are the initial positions, are fitted and fixed to the both ends of the shaft (11), thereby fixing the initial positions. The initial twisting force by the central unit biasing means (28) can be applied to the backrest (7). The function of locking the backrest (7) in the sector gear (41) at an arbitrary rearward tilt position will be described later.
[0026]
The downward projecting pieces (37) and (37) in the left and right disks (38) and (38) are provided below the outer peripheral surface of each outer cylinder (33) in the outermost unit urging means (27) and (29). The locking plate (46) fixed to the pedestal (44) with a set screw (45) (45) is engaged with a portion protruding outward from the outer cylinder (33).
[0027]
The discs (38) (38) and the locking plate (46) are the same as those applied to the outermost unit biasing means (27) (29) and the central unit biasing means (28). This is for applying an initial twisting force.
[0028]
That is, in the outermost unit biasing means (27) (29), the outer cylinder (33) is the same angle as the initial twist angle of the central unit biasing means (28) with respect to the shaft (11). 7 is rotated counterclockwise only in FIG. 7, the locking plate (46) is engaged with the projecting piece (37) of the disc (38) at its outer end, and the outer cylinder ( 33), by fixing with a set screw (45) (45) to the pedestal (44) on the outer peripheral surface of the outer peripheral surface, an initial twisting force similar to that applied to the central unit biasing means (28) is provided on the outermost side. These unit urging means (27) and (29) can also be provided.
[0029]
As described above, in all the unit urging means (27) (28) (29), the outer cylinder (33) is twisted with respect to the shaft (11) by the same initial torsion angle, respectively, so that the backrest is When (7) is stopped at the initial position, the positions of the protrusions (32) of the outer cylinder (33) in all the unit urging means (27) (28) (29) are aligned.
Thus, in the state where the protrusion (32) of the outer cylinder (33) in the central unit biasing means (28) is in contact with the stop piece (35), the other unit biasing means (27) (29) The protrusion (32) of the outer cylinder (33) is positioned above the central protrusion (32), and there is a risk of malfunction such as preventing the movement of the operation member in the left-right direction in the switching means (10) described later. This can be prevented, and the operation of the switching means (10) becomes convenient.
[0030]
As shown in FIG. 5, the switching means (10) is externally fitted to a shaft (22) that is rotated by the operation lever (24) described above, and to be slidable in the left-right direction. The stop piece (47) protruding rearward and the left and right unit urging means (27) (29) can contact the protruding portion (32) of the outer cylinder (33) and the outside thereof. A pair of left and right actuating members (48), (48) that are movable to a non-actuated position disengaged in the direction, and are fixedly fitted to the shaft (22). As the shaft (22) rotates, the left and right actuating members (48) A pair of left and right cylindrical cams (moving members) (49) and (50) that move the inward inwardly independently of each other, and loosely fitted on the shaft (22), and left and right actuating members A compression coil spring (51) which is compressed between (48) and (48) and urges the left and right actuating members (48) and (48) away from each other, and both side walls (5a) of the support base (5) ( 5a) is installed between the front and lower parts, and the stop pieces (47) of the left and right actuating members (48) and (48) are connected to the upper wall (5b) of the support base (5). Sandwiched from above and below and is provided with a detent of the actuating member (48), and a guide bar (52) to fulfill a guide for the horizontal movement.
[0031]
The shapes of the cam surfaces (49a) and (50a) of the left and right cylindrical cams (49) and (50) are determined as shown in the developed view of FIG.
That is, when the operating lever (24) is set to a predetermined 0 ° position, the left and right actuating members (48) and (48) are both in the inoperative position. From this state, the operating lever (24) Is rotated to the 90 ° position, only the left actuating member (48) is pushed rightward against the urging force of the compression coil spring (49), and is positioned at the actuating position. The right actuating members (48) and (48) are located in the non-actuated position as they are.
[0032]
When the operating lever (24) is further rotated to the 180 ° position from that state, the left and right actuating members (48) and (48) are both moved to the left, and the left actuating member (48) The non-actuated position and the right actuating member (48) are located in the actuated position.
[0033]
Furthermore, when the operation lever (24) is rotated to the 270 ° position from that state, only the left operating member (48) is moved to the right, and the left and right operating members (48) (48). Are both located in the operating position.
[0034]
While the operating lever (24) is rotated from the 270 ° position to the 360 ° position, that is, the 0 ° position, the left and right actuating members (48) and (48) are moved to each other by the urging force of the compression coil spring (51). Both are moved outward and are both in the inoperative position.
[0035]
Therefore, when the operating lever (24) is rotated from the 0 ° position to the 270 ° position, the urging force for returning the backrest (7) is minimum when it is 0 ° (central unit urging means (28 )), Slightly smaller at 90 ° (sum of the urging force of the central unit urging means (28) and the urging force of the left unit urging means (27)), slightly at 180 ° Large (sum of urging force of central unit urging means (28) and urging force of right unit urging means (29)), maximum at 270 ° (all unit urging means (27) (28) (The sum of the urging powers of (29)) increases gradually.
[0036]
On the other hand, while the operating lever (24) is rotated from the 0 ° position to the 270 ° position, the distance between the left and right actuating members (48) and (48) gradually decreases gradually, and the compression coil spring ( 51) The operating resistance of the operating lever (24) gradually increases step by step, so that when the operating resistance of the operating lever (24) increases, it is necessary to restore the backrest (7). You can sensibly know that the urging force is also great.
[0037]
As shown in FIG. 4, on the upper surface of the upper wall (5b) of the support base (5), there is a case (54) for accommodating locking means (53) for locking the backrest (7) at a desired rearward tilt angle. It is provided integrally.
In the case (54), an upper surface and both left and right side surfaces are opened, and an accommodation groove (55) is formed which includes a wide portion (55a) in the right half and a narrow portion (55b) in the left half. In the widened portion (55a), two locking plates (56) (57) having teeth (56a) (57a) meshing with the teeth (40) of the sector gear (41) at the right end are stacked vertically. And are slidable in the left-right direction independently of each other.
[0038]
The teeth (56a) and (57a) of the upper and lower locking plates (56) and (57) are formed so as to be shifted back and forth by a half pitch, so only one of the teeth (40) of the sector gear (41) Are designed to mesh.
[0039]
A square hole (58) that is long in the left-right direction and penetrates in the up-down direction is formed in the center of each locking plate (56) (57). Similarly, the lower surface of the left side portion communicates with the square hole (58). A U-shaped groove (59) facing in the left-right direction is formed.
[0040]
On the right side of the narrow width portion (55b), a partition plate (61) cut downward from the center portion of the lid plate (60) that closes the entire upper surface of the case (54) is fitted from above. The partition plate (61) is formed with a U-shaped groove (62) from the upper end to the vicinity of the lower end.
[0041]
On the left side of the partition plate (61) in the narrow width portion (55b), a rectangular tube-shaped connecting piece (63) facing in the vertical direction is fitted so as to be slidable in the horizontal direction.
In the center of the right side wall of the connecting piece (63), U-shaped grooves (64) (65) are formed symmetrically from the upper and lower edges toward the middle position, and at the center of the upper edge of the left side wall, A U-shaped groove (66) facing downward is formed.
[0042]
U-shaped grooves (59) (59) in the upper and lower locking plates (56) (57), U-shaped grooves (62) in the partition plate (61), and upper and lower U-shaped in the right side wall of the connecting piece (63) A pair of upper and lower rods (67) and (68) facing the left and right direction having enlarged diameter flanges (67a) and (68a) at both ends are slidably fitted in the grooves (64) and (65). ing.
[0043]
Between the right-side expanded diameter rod (67a) (68a) of the upper and lower rods (67) (68) and the left end surface of the square hole (58) in the upper and lower locking plates (56) (57), The compression coil springs (69) (69) loosely fitted on the rods (67) (68) are respectively contracted, and the left end surfaces of the upper and lower locking plates (56) (57) and the partition plates (61 The compression coil springs (70), (70) loosely fitted to the rods (67), (68) are respectively contracted between the right side surfaces.
[0044]
The magnitude of the urging force between the compression coil spring (69) and the compression coil spring (70) is almost the same, or the compression coil spring (69) is set to be slightly larger than the compression coil spring (70). It is preferable to keep it.
[0045]
The U-shaped groove (66) on the left side wall of the connecting piece (63) has a pull lock / pull release mechanism (71) provided further to the left than the connecting piece (63) in the narrow width portion (55b). The right end portion of the shaft (72) provided with the expanded diameter rod (72a) is fitted.
[0046]
In the pull lock / pull release mechanism (71), the shaft (72) penetrates the rectangular tube case (73) provided in the narrow portion (55b) in the left-right direction, and the shaft (72) is passed through the case ( 73) Once pulled to the left from the left end side protruding from the left end, a known rotary repetitive locking mechanism provided in the case (73), similar to the so-called knock type ballpoint pen, Next, when the shaft (72) is pulled to the left again, the locking state of the rotary repetitive locking mechanism is released, and the return spring (built in the case (73) ( When the shaft (72) is moved to the right by the (not shown) and thereafter the shaft (72) is pulled to the left, the rotary repetitive locking mechanism alternately repeats the locked state and the unlocked state. It is like that.
[0047]
The left / right movement stroke of the shaft (72) is such that one of the teeth (56a) (57a) of the two locking plates (56) (57) meshes with the tooth (40) of the sector gear (41). This is greater than the required travel.
[0048]
The left end of the shaft (72) has a cable (75) inserted through the flexible sheath tube (74), and an operating lever (76) provided on the lower surface of the front end of one armrest (14) ( The shaft (72) is pulled to the left whenever the operating lever (76) is rotated upward.
[0049]
When the locking means (53) is assembled to the support base (5), the locking plates (56) (57), the connecting pieces (63), the rods (67) ) (68), compression coil springs (69) (70), and pull lock / pull release mechanism (71) are all reversed and assembled in sequence, then they are integrated and reversed while the housing groove ( 55) should be fitted.
[0050]
As shown in FIG. 9, when the shaft (72) is pulled to the left and locked, the connecting piece (63) is moved to the left by the enlarged diameter rod (72a) at the right end thereof. Along with this, the upper and lower rods (67) (68) are also moved to the left, and normally the upper and lower locking plates (56) (57) are balanced by the balance of the urging forces of the compression coil springs (69) (70). ) Is stopped at the inoperative position where the teeth (56a) and (57a) are disengaged leftward from the teeth (40) of the sector gear (41).
[0051]
In this state, the backrest (7) is always urged toward the standing position by the urging force adjusted by the operating lever (24), and is pushed back against the urging force. It can be tilted backward with the resistance of.
[0052]
In this state, after tilting the backrest (7) to a desired angle and then rotating the operating lever (76) upward, the shaft (72) is once moved to the left, and a pull lock / pull release mechanism ( 71) is released, and the shaft (72) is moved to the right as shown by the solid line in FIG. 10, and accordingly, the connecting piece (63), the upper and lower rods (67) (68), and the upper and lower The locking plates (56) and (57) are moved to the right by the balance of the urging forces of the compression coil springs (69) and (70), and one of the upper and lower locking plates (56) and (57) The teeth (56a) (57a) mesh with the teeth (40) of the sector gear (41).
[0053]
If they do not mesh immediately, if the backrest (7) is slightly tilted back and forth, any of the teeth (56a) (57a) will always mesh with the teeth (40) of the sector gear (41). .
[0054]
After any tooth (56a) (57a) (upper tooth (56a) in FIG. 10) meshes with the tooth (40) of the sector gear (41), the backrest (7) is locked in its position, Even if the seated person leaves his back from the backrest (7), the backrest (7) does not move forward or backward from that position.
[0055]
When the back lever (7) is locked and the control lever (76) is turned upward again, the pull-lock / pull release mechanism (71) is moved to the left after the shaft (72) is once moved to the left. It is locked and the shaft (72) is locked in a state of being moved to the left, and accordingly the teeth of the connecting piece (63), the upper and lower rods (67) (68), and the sector gear (41) One of the upper and lower locking plates (56) and (57) (in this example, the lower locking plate (57) in this example) not engaged with (40) is moved to the left.
[0056]
However, the large urging force by the urging means (9) is applied to the locking plate (56) (or (57)), which is meshed with the teeth (40) of the sector gear (41), in a substantially perpendicular direction. However, it does not immediately disengage from the sector gear (41), but only when a load against the urging force is applied, such as when a seated person leans on the backrest (7), it disengages from the sector gear (41). However, it is moved to the left by the balance of the urging forces of the compression coil springs (69) and (70).
The upper and lower locking plates (56) and (57) are not directly connected to the upper and lower rods (67) and (68), but are provided with play by interposing compression coil springs (69) and (70) in both the left and right directions. This is why.
[0057]
As is apparent from the above, according to this embodiment, the urging force for returning the backrest (7) can be adjusted stepwise over a large range by rotating the operation lever (24). At the same time, the backrest (7) can be locked at a desired rearward tilt angle or released from the locked state by the operation lever (76).
[0058]
In this example, the backrest and the seat are supported on the support base so that they can be tilted rearward and downward in conjunction with each other, and both of them are biased forward and upward with a biasing means for return. However, the present invention can also be applied to a structure in which only one of the backrest and the seat is supported on the support base so as to be tiltable rearward and downward.
[0059]
Further, the number of unit urging means may be two or four or more, and all the urging forces may be selected and transmitted to the backrest or the seat.
[0060]
【The invention's effect】
According to the first aspect of the present invention, since the urging force of the plurality of unit urging means is selected by the switching means and transmitted to the backrest or the seat, the urging force of the urging means is greatly changed. It is possible to expand the selection range of the seated person and obtain a comfortable seating feeling according to the seated person's preference.
[0061]
According to the second aspect of the present invention, the structure of each unit urging means can be simplified, and a plurality of them can be arranged side by side in a compact manner, and by doing so, the switching means In addition, the entire tilting device can be reduced in size.
[Brief description of the drawings]
FIG. 1 is a front view of a chair provided with an embodiment of the present invention.
FIG. 2 is a side view of the same.
FIG. 3 is an exploded perspective view of the support base and the urging means inside the support base.
FIG. 4 is an exploded perspective view of the support base and the locking means at the upper part of the same.
5 is an enlarged cross-sectional plan view taken along line VV in FIG.
6 is a longitudinal side view taken along line VI-VI in FIG.
7 is a longitudinal side view taken along the line VII-VII in FIG.
FIG. 8 is also a development view of the cam surfaces of the left and right cylindrical cams in the switching means.
FIG. 9 is a schematic plan view showing the unlocking state of the locking means, similarly;
FIG. 10 is a schematic plan view showing the locked state of the locking means, similarly;
[Explanation of symbols]
(A) Tilt device
(1) Casters
(2) Legs
(3) Leg
(4) pedestal
(5) Support base
(5a) Side wall
(5b) Upper wall
(6) Cover
(7) Backrest
(8) Seat
(9) Energizing means
(10) Switching means
(11) axis
(12) Back support
(12a) Tube part
(13) Headrest
(14) Armrest
(15) Seat support rod
(16) Guide rail
(17) Axis
(18) Yokohama
(19) Support link
(20) axis
(21) Tube part
(22) Axis
(23) Torsion coil spring
(24) Control lever
(25) Leg piece
(26) Movable rail
(27) (28) (29) Unit biasing means
(30) Hexagon hole
(31) Core material
(32) Projection
(33) Outer cylinder
(34) Elastic body
(35) Stop piece
(36) Hexagon hole
(37) Projection
(38) Disc
(39) Long hole
(40) Teeth
(41) Sector gear
(42) Stop plate
(43) Set screw
(44) Pedestal
(45) Set screw
(46) Locking plate
(47) Stop piece
(48) Actuating member
(49) (50) Cylindrical cam (moving member)
(49a) (50a) Cam surface
(51) Compression coil spring
(52) Guide bar
(53) Locking means
(54) Case
(55) Accommodation groove
(55a) Widening part
(55b) Narrow part
(56) (57) Locking plate
(56a) (57a) teeth
(58) Square hole
(59) U-shaped groove
(60) Lid plate
(61) Partition plate
(62) U-shaped groove
(63) Connection piece
(64) (65) (66) U-shaped groove
(67) (68) Rod
(67a) (68a)
(69) (70) Compression coil spring
(71) Pull lock / pull release mechanism
(72) Shaft
(72a) Diameter expansion 鍔
(73) Case
(74) sheath tube
(75) Cable
(76) Control lever

Claims (2)

In a tilting device such as a backrest in a chair in which the backrest or seat can be tilted against the biasing force of the return biasing means, the biasing means comprises a plurality of unit biasing means And a backrest in a chair characterized by providing switching means for selectively switching so as to enable or disable transmission of the urging force of each unit urging means to the backrest or seat Tilting device. Each unit biasing means is integrated with a support rod that supports the backrest or seat so that the seat can be tilted, and rotates around the central axis, and is substantially concentric with the core material. An outer cylinder that is prevented from rotating by abutting a support base or switching means that supports the flange and a space between the core material and the outer cylinder are filled, and the core material is a central axis with respect to the outer cylinder. elastically deformed by rotating around the tilting equipment, such as the backrest of the chair by being according to claim 1, wherein an elastic member that supplies a return rotational force to the core material.

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