JP6952509B2 - Chair - Google Patents

Description

The present invention relates to a seat surface (front) deformation mechanism of a chair that responds to changes in the posture of a seated person. In particular, the present invention relates to a mechanism that enables deformation not only due to the properties of the members of the seat surface.

When using a chair, the thighs are supported by the front part of the seat, and if this is continued for a long time or the front part of the seat rises when the back leans backward, when leaning backward The pressure on the thighs became noticeable, and the same was true during work leaning forward.

Therefore, as a chair in which the front portion of the seat can be deformed up and down by the load of the seated person, for example, those shown in Patent Documents 1 and 2 are shown.

Japanese Patent No. 4272031 Japanese Unexamined Patent Publication No. 2004-033543

However, it is not always sufficient to make the front part of the seat deformable up and down.

Since it is painful to maintain the same posture on the seat surface for a long time, the user continues to sit while unknowingly changing his / her posture. This change in posture involves twisting the lower body, especially the left and right sides of the buttocks and thighs, to raise the left and right sides and lower the other to avoid pressure on the buttocks and thighs. Is natural. At this time, the buttocks and thighs on the transferred side are subjected to great pressure.

Deformation of the front part of the seat alleviates the pressure to some extent, but if the amount of deformation is too small, it is insufficient to avoid the pressure, and if the amount of deformation is large, the support function of the front part of the seat at normal times Will decrease.

Therefore, there is a limit to solving these problems only by deforming the front part of the seat.

Focusing on such a problem, the present invention aims to realize a chair that can more appropriately support the legs of a seated person.

The present invention has taken the following measures in order to achieve such an object.

That is, it is premised that the chair of the present invention is provided with a deformed portion that changes its shape in the vertical direction in response to a seating load on the front portion of the seat, and supports the seat so as to be swingable back and forth and left and right with respect to the support base. And.

In this way, the seat swings back and forth and left and right with respect to the support base in combination with the deformation operation of the deformed portion provided on the front part of the seat, so that the support function of the seat is properly maintained. , The pressure on the thighs and buttocks can be relieved synergistically.

The seat is formed by arranging a cushioning material on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion. Since the deformed part of the seat shell regulates the range when the deformed part of the seat shell deforms in the vertical direction, the deformed part can be operated within the proper range, and the deformed part can be operated on the outside of the seat shell. The outer shell is provided at a distance so that the deformed portion of the front part of the seat shell can be deformed toward the outer shell, and the front cover is attached to the deformed part of the front seat shell so as to sandwich the outer shell. Since the front cover is brought into contact with the outer shell when the deformed portion of the seat shell is separated from the outer shell by a predetermined distance, a preferable structure can be obtained.

Further, the seat has a cushioning material arranged on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion. The seat shell has a simple structure because the rear part is engaged with the leaf springs provided at least at two positions on the left and right and the front part is elastically contacted. Since the deformation reaction force of the deformed portion can be changed by the relative position of the seat shell and the leaf spring, it is possible to correspond to the weight of the leg.

Further, the seat has a cushioning material arranged on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion. An appropriate deformation movement can be realized, and a regulation member that regulates the deformation range is provided below the front part of the seat shell. Since it is configured so as to be relatively downward with respect to the front part of the body and to increase the deformation range of the deformed part, it is possible to realize support according to the posture.

In order to more appropriately correspond to the weight of the legs, it is desirable that the regulating member be configured to support the seat shell when it is deformed against the elastic force under the seating load.

In order to properly set the regulation position, it is desirable that the regulation member is connected to a front-rear support portion that supports the back seat so as to be movable back and forth via an interlocking mechanism.

In order to realize appropriate support according to the pressure contact condition of the leg, the deformed portion is the leg of the seated person.
It is provided at the position to receive the weight of the leg, and when it receives the weight of the leg, it deforms downward and the weight of the leg becomes
It is desirable that it is configured to return upward when it comes off.

The present invention is particularly designed for a chair in which the back can be tilted backward so that the back can be tilted backward, and when the back is tilted backward, the seat is interlocked to perform an operation in which the front portion is relatively raised and the rear portion is lowered. It is valid.

Considering that the left and right eccentric loads are applied to the front portion of the seat, it is desirable that the deformed portion is twisted and deformed according to the eccentric load applied to the left side region and the right side region of the seat.

According to the present invention, it is possible to provide a new chair that can more appropriately support the legs of the seated person.

A diagonally forward perspective view of a chair according to an embodiment of the present invention. A diagonal rear perspective view with a part of the chair removed. A perspective view of the front, rear, left, and right support parts of the chair. A perspective view showing a state in which a left-right swinging portion is incorporated in a support base of the chair. The perspective view which shows the state which incorporated the front-rear swing part into the left-right swing part. A perspective view of a part of FIG. 5 viewed from diagonally below. A perspective view showing a part of FIG. 4 in an enlarged manner. FIG. 4 is a perspective view showing a state in which the left and right stopper mechanisms are incorporated. The operation explanatory view of the left-right swing part. The operation explanatory view of the left-right swing part. The operation explanatory view of the front-rear swing part which shows a part through see-through. The operation explanatory view of the front-rear swing part which shows a part through see-through. The operation explanatory view of the front-rear swing part which shows a part through see-through. An exploded perspective view showing the relationship between the front-rear swinging portion and the back. The perspective view which shows the weight receiving part provided in the seat. An exploded perspective view of a front-rear stopper mechanism and a control mechanism that suppresses front-rear movement. Assembly perspective view of the front-rear stopper mechanism and the control mechanism that suppress the front-rear movement. FIG. 17 is a perspective view seen from diagonally below. An exploded perspective view of the left and right stopper mechanism that suppresses left and right movement. Partially assembled perspective view of the left and right stopper mechanism that suppresses left and right movement. The schematic diagram which shows the suppression operation of front, back, left and right. An operation explanatory view of the left and right stopper mechanism. An operation explanatory view of the left and right stopper mechanism. An operation explanatory view of the front and rear stopper mechanism. An operation explanatory view of the front and rear stopper mechanism. An operation explanatory view of a control mechanism that operates according to a seated state. The partially cutaway perspective view which shows the engaging part of a bearing and a guide hole in the same embodiment. The figure explaining the processing procedure of a guide hole. An exploded perspective view showing the movement mechanism of the back. An exploded perspective view showing the structure of the back. Cross-sectional view of the back including the operating mechanism. Explanatory drawing of the guide part which constitutes an operation mechanism. An operation explanatory view corresponding to FIG. 31. An operation explanatory view corresponding to FIG. 31. An operation explanatory view relating to the turning operation of the backrest. An exploded perspective view showing a regulated part that regulates the movement of the back. The perspective view which shows the lower surface of the seat. An exploded perspective view of the seat. Enlarged cross section of the front of the seat. The figure which shows the operation of the deformed part. The side view which shows the regulation structure which concerns on the modification of this invention. An operation explanatory view corresponding to FIG. 41. An operation explanatory view corresponding to FIGS. 41 and 42. The perspective view which shows the leaf spring support structure which concerns on other modification of this invention. An operation explanatory view corresponding to FIG. 44.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

In this chair, as shown in FIGS. 1 to 5, a leg strut 13 having an elevating mechanism internally provided is erected at the center of the leg blade 12 supported by the casters 11, and the chair is supported on the upper end side of the leg strut 13. It is an office chair configured by rotatably attaching the base 2. The support base 2 swings back and forth as a one-way moving portion (movable portion) capable of operating in one of the two intersecting directions, the front-rear direction (X direction in the figure) and the left-right direction (Y direction in the figure). The seat 5 which is a movable portion is supported via the portion 3 and the left-right swing portion 4 which is an other-direction operating portion (support portion) capable of operating in any of the front-rear, left-right, and other directions, and the seat 5 is supported by the support base portion 2. It is possible to swing back and forth and left and right. Specifically, a front-rear swing portion 3 is provided between the seat 5 and the support base portion 2 that supports the seat 5, and a left-right swing portion 4 is provided between the front-rear swing portion 3 and the support base portion 2. .. A back 6 is arranged behind the seat 5.

The support base 2 serves as a structure that receives the load of the seated person, and the bearing bases 22 are provided on the left and right sides of the support base 21 having the vertical through holes 21a into which the upper ends of the columns 13 are inserted. A pair of left and right elbow mounting portions 23 are integrally formed via the interposition. A shaft swing damper 21b is attached to the hole 21a that opens in the front-rear surface of the bearing base 21, and the upper ends of the left-right swing links L1 and L2 swing in the hole 22a that opens in the front-rear surface of the bearing base portion 22. It is attached via the bearing shafts S1 and S2.

The left-right swinging portion 4 is formed between a pair of plate-shaped link bases 41 arranged apart from each other in the front-rear direction and the pair of link bases 41, 41 so as to swing left and right with respect to the support base portion 2. The left and right swing main body 42 is provided, and holes 41a and 41a are opened at both left and right ends of the link base 41, and the lower ends of the left and right swing links L1 and L2 form swing shafts S3 and S4. Attached via. FIG. 4 shows a state in which the links L1 and L2 are attached via the swing shafts S1 to S4. As shown in FIGS. 7 and 8, the left-right swing main body 42 is provided with a unit mounting hole 42a penetrating in the vertical direction, and the left-right lock unit 7 described later is mounted in the unit mounting hole 42a. That is, the left-right swing main body 42 is arranged in a state of being suspended from the support base 2 via the left-right swing links L1 and L2 so as to be swingable left and right, and the left-right swing links L1 and L2 are as shown in FIG. It is installed so that the distance between the lower ends is smaller than the distance between the upper ends.

That is, when the left-right swing portion 4 swings, as shown in FIGS. 9 to 10, the link L2 (L1) located at the swing destination approaches the vertical posture, and the other link L1 (L2) is horizontal. As a result of approaching the posture, the center of gravity of the left-right swinging portion 4 is lifted while inclining so that the moving tip side becomes lower.

A window 41c is opened in the central portion of the link base 41, and the rolling damper 44 is positioned in the window 41c, and the left-right swinging portion is within a range in which the rolling damper 44 can move relative to each other in the window 41c. The swing range of 4 is regulated.

The front-rear swinging portion 3 is a pair of plate-shaped rail plates 31 and 31 and a pair of rail plates 31 which are arranged so as to swing back and forth with respect to the left-right swinging portion 4. , 31 is provided with an upper connecting plate 32 and a front connecting plate 33 for connecting between the 31. A guide hole 34 is provided through the front side of the rail plate 31, and the rolling element 45 is provided in the guide hole 34 on the side surface of the left-right swing main body 42 on the front end side so as to be independently rollable. The bearing 45a is engaged. Reference numeral 45z in the figure is a spacer arranged on the inner surface side of the rail plate 31 and having a diameter larger than that of the bearing 45a. The rear end side of the rail plate 31 extends rearward and downward, and the lower end portion of the link arm LA, which is a front-rear swing link that can swing via the swing shaft S5, is attached to the extension end. The upper end portion of the arm LA is supported by the rear end portion of the left-right rocking body 4 via the swing shaft S6. That is, the rear end portion of the front-rear swing portion 3 is arranged in a state of being suspended from the left-right swing portion 4 so as to be swingable back and forth via the link arm LA. The guide hole 34 has a shape that gently curves forward and downward from the rear end side to the front end side, and at the rear end portion, the impact when the front-rear swinging portion 3 moves forward together with the seat 5 is alleviated. A shockless portion SL is formed. The upper connection plate 32 is provided with a unit mounting hole 32a penetrating in the vertical direction, and a front-rear lock unit 8 described later is mounted in the unit mounting hole 32a based on FIG. In the illustrated example, the axles of the bearing 45a, which is the rolling element 45, are separated on the left and right. However, if the bearing 45a, which is the rolling element 45, can roll independently on the left and right, the axles may be shared.

That is, when the front-rear swinging portion 3 moves backward as shown in FIG. 12 from the state of FIG. 11 in which the upper surface of the front-rear swinging portion 3 takes a substantially horizontal posture, the bearing 45a is placed on the front end side of the guide hole 34 at the front end portion. Moves relative to each other and the front end side of the front-rear swing portion 3 is lifted to a high position, and as a result of the link arm LA approaching the vertical posture, the rear end side of the front-rear swing portion 3 is guided to a low position. On the contrary, when the front-rear swinging portion 3 moves forward as shown in FIG. 13 from the state of FIG. 11, the bearing 45 moves relative to the rear end side of the guide hole 34 at the front end portion, and the front end of the front-rear swinging portion 3 As a result of guiding the side to a lower position and the link arm LA approaching the horizontal posture, the rear end portion of the front-rear swinging portion 3 is lifted to a higher position. That is, the front-rear swinging portion 3 performs an operation of inclining so that the moving tip side becomes lower even in the front-rear direction.

A vertical swing damper 31c is provided on the front end side of the rail plate 31 constituting the front-rear swing portion 3 by bending a part thereof, and when the front-rear swing portion 3 swings backward, it swings left and right near the swing end. The shock at the rear moving end is alleviated by abutting on the lower front end 4z (see FIG. 3) of the moving portion 4.

As shown in FIG. 14, the back frame 61 constituting the back 6 is attached to the rear portion of the upper connecting plate 32 forming the front-rear rocking body 3, and the seat outer shell 51 (see FIG. 15) constituting the seat 5 is above it. It is attached to the connection plate 32 from. That is, when the back frame 61 that supports the backrest 62 stands behind the seat 5 integrally and the seat 5 swings back and forth and left and right with respect to the support base 2 as shown by X and Y in the figure, the back The frame 61 also moves together, but the backrest 62 of the present embodiment performs an operation separated from the back frame 61 and the seat 5 as described later.

The front-rear swing of the seat 5 with respect to the support base 2 in the front-rear direction using the front-rear lock unit 8 shown in FIGS. 16 to 18 so as to be suppressed at a predetermined position through the operation of the operation member 152 shown in FIG. A stopper mechanism 8M is provided, and the lateral swing of the seat 5 with respect to the support base 2 is performed in advance through the operation of the operation member 151 (actually, the common operation member is also used together with the operation member 152) shown in FIG. A left and right stopper mechanism 7M using the left and right lock units 7 shown in FIGS. 19 and 20 is provided so that the left and right lock units 7 can be suppressed at a predetermined position.

In this embodiment, since the support base 2 supports the left-right swing portion 4 and the left-right swing portion 4 supports the front-rear swing portion 3, the support base 2 and the left-right swing portion 2 and the left-right swing portion 3 have a multi-layered structure. A left-right stopper mechanism 7M is provided between the portions 4, and a front-rear stopper mechanism 8M is provided between the left-right swing portion 4 and the front-rear swing portion 3.

The left and right stopper mechanism 7M is operated by the operating member 151 shown in FIG. 15 to engage or disengage the engaging portion 71 and the engaged portion 72 shown in FIG. It switches whether to allow or suppress directional swing. Specifically, the engaging pin 71a, which is an engaging portion 71 provided on the left-right swinging portion 4 side, and the sliding surface 20 which is on the support base 2 side, which is the opposite position of the engaging pin 71a, and operates relative to each other. The engaging pin 71a is elastically urged toward the sliding surface 20 and the engaging pin 71a is fitted into the groove 72a at a predetermined position. It is configured. As shown in FIGS. 3 and 7, the groove 72a has a rectangular shape in a plan view provided at a central reference position in the left-right direction of the support base portion 2 exposed upward through the opening 4t of the left-right swing portion 4. The engagement pin 71a shown in FIG. 20 engages and disengages from the groove 72a. The coil spring 73a, which is an elastic member 73, plays a role of urging the engaging pin 71a in the direction of projecting toward the sliding surface 20. Further, the left and right stopper mechanism 7M has a conversion mechanism 74 shown in FIGS. 19 and 20 for converting the operation of the operating member 151 into an operation in the direction in which the engaging pin 71a is separated from the sliding surface 20, and the conversion mechanism 74 is engaged. The matching pin 71a and the coil spring 73a are integrally incorporated into the casing 70 of the left and right lock units 7 to form a unit.

As shown in FIG. 19, the casing 70 has a half-split structure, and the engaging pin 71a has a wide portion 71aw that is guided by the inner surfaces of the side walls 70a and 70b of the casing 70 and is a part from the lower end of the casing 70. It is arranged so as to be able to move up and down with the portion 71as protruding. The conversion mechanism 74 has a casing at a position adjacent to the above-mentioned coil spring 73a, which is elastically installed between the upper end of the engagement pin 71a and the upper wall 70p of the casing 70, and the engagement pin 71a via the horizontal shaft 70c. A stopper operating arm 75 rotatably supported between the side walls 70a and 70b of the 70, a torsion coil spring 76 rotatably attached together with the stopper operating arm 75, and a spherical wire tip 77a attached to the stopper operating arm 75. At the same time, the tube tip 77b is composed of a wire tube 77 locked to the casing 70. As shown in FIG. 15, the other end of the wire tube 77 is locked in the vicinity of the operating lever 151a which is an operating member 151 provided on the seat 5, and the wire base end 77c drawn out from the operating lever 151a is connected to the operating lever 151a. There is. The tip 76b of the torsion coil spring 76 is engaged with the hole 71a1 provided in the engagement pin 71a.

The casing 70 is fitted into the unit mounting hole 42a of the swinging main body 42 constituting the left-right swinging portion 4 shown in FIG. 7, and the state shown in FIG. 8 is obtained. It is placed on the upper surface of the casing and fixed with screws. The left and right side walls 70a and 70b of the casing 70 are tightly housed in the left and right side walls 42a1 and 42a2 of the unit mounting hole 42a, and the engagement pin 71a is tightly guided to the inner surfaces of the side walls 70a and 70b of the casing 70 in the casing 70. Will be done. Since the engagement pin 71a is suppressed from rattling to the left and right in this way, the unit mounting holes 42a of the left-right swinging portion 13 shown in FIG. 7 are the left and right side walls 42a1, 42a2, the rear wall 42a3, and the inclined front wall. It is composed of only 42a4 and forms a lower opening 4t without a bottom wall, and the engaging pin 71a hangs directly from the lower opening 4t of the unit mounting hole 42a without being guided by the bottom wall. It is configured to come into contact with the sliding surface 20 and engage with the groove 72a. The front-rear direction of the engagement pin 71a is supported by the front-rear guide walls formed in the casing 70. The groove 72a is formed between the vertical ribs r1 and r1 provided on the support base 2. The horizontal ribs r2 are provided around the vertical ribs r1 and r1, and the vertical ribs r1 are provided until they engage with the groove 72a. The upper surface of the lateral rib r2 serves as a sliding surface 20 to slide the engaging pin 71a.

As shown in FIG. 22, when the operating lever 151a is in the unlocked position, the wire tube 77 rotates the stopper operating arm 75 to compress the coil spring 73a, and the tip 76b of the torsion coil spring 76 causes the engaging pin 71a. When the operating lever 151a is operated to the locked position, the tip 76b of the torsion coil spring 76 rotates together with the stopper operating arm 75 due to the repulsive force of the coil spring 73a, as shown in FIG. When the engagement pin 71a is pressed downward and engages with the groove 72a of the support base 2, a locked state in the left-right direction is realized.

The front-rear stopper mechanism 8M is operated by the operating member 152 shown in FIG. 15 to engage or disengage the engaging portion 81 and the engaged portion 82 shown in FIG. It switches whether to allow or suppress directional swing. Specifically, the engaging pin 81a, which is an engaging portion 81 provided on the front-rear swinging portion 3 side, and the sliding that are on the left-right swinging portion 4 side, which is the opposite position of the engaging pin 81a, and operate relative to each other. A groove 82a which is an engaged portion 82 provided on the surface 40 is provided, the engaging pin 81a is elastically urged toward the sliding surface 40, and the engaging pin 81a is fitted into the groove 82a at a predetermined position. It is configured as follows. As shown in FIG. 7, the groove 82a is a range of movement when the engaging pin 81a of the front-rear swing portion 3 mounted on the upper surface of the swing body portion 42 of the left-right swing portion 4 moves in the front-rear direction. It is provided at one or more predetermined locations (one in the present embodiment), has a shape extending in the left-right direction, and the upper surface of the swing main body 41 forms a sliding surface 40. The coil spring 83a, which is an elastic member 83, plays a role of urging the engaging pin 81a in the direction of projecting toward the sliding surface 40, and the engaging pin 81a operates the operating member 152 from the sliding surface 40. It has a conversion mechanism 84 shown in FIGS. 16 and 17, and the conversion mechanism 84, the engagement pin 81a, and the coil spring 83a are integrally incorporated into one half of the casing 80 to form a unit.

The casing 80 has a flat saucer shape that is open upward, and the engaging pin 81a is guided by the guide 80g1 in the casing 80 and is arranged so as to be able to move up and down with a part protruding from the lower end of the casing 80. There is. The conversion mechanism 84 is located adjacent to the coil spring 83a described above, which is installed in a compressed state between the upper end of the engaging pin 81a and the cover 80a that closes the upper opening of the casing 80, and the casing 80 at a position adjacent to the engaging pin 81a. A stopper operating arm 85 rotatably supported by a horizontal shaft 80c erected between the side walls 80b and 80b, a torsion coil spring 86 rotatably attached together with the stopper operating arm 85, and a spherical wire attached to the stopper operating arm 85. The tip 87a is attached and the tube tip 87b is composed of a wire tube 87 locked to a casing 80. As shown in FIG. 15, the other end of the wire tube 87 is locked in the vicinity of the operating lever 152a, which is an operating member 152 provided on the seat 5, and the wire base end 87c drawn out from the operating lever 152a is connected to the operating lever 152a. There is. The tip 86a of the torsion coil spring 86 is always smoothly and slidably engaged with the downward surface 81a1 of the engagement pin 81a.

When the operating lever 152a shown in FIG. 15 is in the unlocked position, the wire tube 87 shown in FIG. 17 rotates the stopper operating arm 85 as shown in FIG. 24 to compress the coil spring 83a and twist the coil spring 86. When the engagement pin 81a is pulled upward by the tip 86a and the operation lever 152a is operated to the locked position, the tip of the torsion coil spring 86 is operated together with the stopper operation arm 85 by the repulsive force of the coil spring 83a as shown in FIG. When the 86a rotates and the engagement pin 81a is pressed downward and this engages with the groove 82a of the left-right swing portion 4, a locked state in the front-rear direction is realized.

In the chair of this embodiment, a control mechanism 8X for automatically suppressing the movement of the seat 5 in the front-rear direction at a predetermined position is provided in one half of the unit 8 of the front-rear stopper mechanism 8M. ing.

First, in order to detect seating, a weight receiving portion 50 (see FIG. 15) whose height position changes depending on sitting on the seat surface is provided at approximately the center position of the seat 5, and the change in height position is performed by the movable portion. It is mechanically transmitted to the control mechanism 8X shown in FIGS. 16 and 18 for controlling the operation of a certain front-rear swinging portion 3, and the control mechanism 8X allows the movement of the front-rear swinging portion 3, that is, the front-back movement of the seat 5. It is configured to change its state during suppression.

The control mechanism 8X is a left-right swing portion 4 which is a support portion for supporting the engagement portion 81X and the front-rear swing portion 3 shown in FIG. 21 (c) provided in the front-rear swing portion 3 which is a movable portion by a seating load. The engaged state of the engaged portion 82X provided in the above changes to change the allowed / suppressed state of the movement of the front-rear swinging portion 3, and the operating state allowed by the elastic member 83X when the seating load is removed. Restores the original suppressed operating state.

The engaged portion 81X and the engaged portion 82X are disengaged by the seating load, and when the seating load is removed, the engaged portion 82X engages with the elastic force to put the front-rear swinging portion 3 in an operation-suppressed state. Is a recess 82aX, and the engaging portion 81X is configured to be released from the fitted state by receiving a seating load from the state where the engaging portion 81X is fitted in the recess 82aX.

The control mechanism 8X is a groove-shaped recess 82aX which is an engaged portion 82X provided on a sliding surface 40X which is located at a position facing the engaging pin 81X and which operates relative to the engaging pin 81aX which is an engaging portion 81X. The engaging pin 81aX is elastically urged toward the sliding surface 40X, and the engaging pin 81aX is configured to fit into the groove-shaped recess 82aX at a predetermined position. Then, when the seat 5 detects that the seat 5 has received the seating load in the central portion, the control mechanism 8X shown in FIGS. 16 to 17 separates the engaging pin 81aX from the groove-shaped recess 82aX. The coil spring 83aX, which is an elastic member 83X, plays a role of urging the engaging pin 81aX in the direction of projecting toward the sliding surface 40X, and the control mechanism 8X controls the operation of the weight receiving portion 50 by sitting on the engaging pin. The 81aX has a conversion mechanism 84X that converts the movement in the direction away from the sliding surface 40X, and the conversion mechanism 84X, the engagement pin 81aX, and the coil spring 83aX are integrally incorporated in the other half of the casing 80 shown in FIG. It is unitized.

The engaging pins 81aX are arranged in a flat casing 80 constituting the front / rear stopper mechanism 8M so as to be able to move up and down along the front / rear / left / right guides 80g2 of the casing 80 in a parallel relationship with the engaging pins 81. The conversion mechanism 84X includes a coil spring 83aX which is elastically installed in a compressed state between the upper end of the engagement pin 81aX and the cover 80a which closes the upper opening of the casing 80 in a part similar to the conversion mechanism 84. A safety operation arm 85X rotatably supported by the horizontal shaft 80c erected between the side walls 80b and 80b of the casing 80 at a position adjacent to the engagement pin 81aX, and a torsion coil spring rotatably attached together with the safety operation arm 85X. It is composed of 86X. On the other hand, the weight receiving portion 50 is a pressure receiving plate 52a rotatably fitted and attached to the seat outer shell 51 constituting the seat 5 as shown in FIG. 15, and the convex portion 52b provided below the pressure receiving plate 52a. Is arranged at a position where the pressed portion 85xt shown in FIG. 16 displaced from the rotation center of the safety operation arm 85X can be pressed. The tip 86aX of the torsion coil spring 86X is always smoothly and slidably engaged with the downward surface of the engagement pin 81aX. The pressure receiving plate 52a is urged by a coil spring 52c, which is an elastic body shown in FIG. 26, in a direction away from the safety operating arm 85X. As shown in FIG. 37, a hole 53x for avoiding interference with the pressure receiving plate 52a is provided at a corresponding position of the seat inner shell 53.

As shown in FIG. 26B, when the weight receiving portion 50 does not detect the weight, the engaging pin 81X is moved downward by the coil spring 83aX while the tip 85aX of the torsion coil spring 85X is rotating together with the safety operation arm 85X. When pressed and engaged with the groove 82aX of the front-rear swinging portion 4, a locked state in the front-rear direction is realized, and as shown in FIG. 26A, the weight receiving portion 50 detects the weight and the torsion coil spring 86X. When the engaging pin 81X is pulled upward while compressing the coil spring 83aX at the tip 86aX of the above, the engaging pin 81X is disengaged from the groove-shaped recess 82aX, and the locked state in the front-rear direction is released.

That is, when the user sits down, the lock of the control mechanism 8X is released, and then whether or not the seated person locks in the front-rear direction depends on the state of the front-rear fixed stopper mechanism 8M through the operation of the operation member 152. When leaving the seat, if the front / rear fixing stopper mechanism 8M is not unlocked, the state is maintained, and if the front / rear fixing stopper mechanism 8M is unlocked, the control mechanism 8X is activated to lock the seat 5 to the front / rear movement. Will be multiplied.

In particular, in this chair, the seat 5 tilts at least back and forth, and when the seater starts to stand up, the seat 5 moves together with the front-rear swinging portion 3 while tilting forward as shown in FIG. When the seating load is removed by leaving the seat at, the engaging pin 81aX, which is the engaging portion 81X shown in FIG. 21C, lands on the sliding surface 40X in front of the recess 82aX, which is the engaged portion 82X. After that, the seat 5 starts moving while tilting backward due to the positional relationship of the center of gravity of the back seat due to the presence of the back 6, and the engaging pin 81aX which is the engaging portion 81X is the recess 82aX which is the engaged portion 82X in the middle. The action of engaging with is expected. As shown in FIG. 7, grooves are continuously provided in the recess 82aX in the orthogonal direction, and a cushioning material 82z such as rubber is embedded therein. The cushioning material 82z is for preventing the engaging pin 81aX from colliding with the wall of the recess 82aX to generate an impact or an abnormal noise, and the engaging pin 81aX collides with the cushioning material 82z and falls into the recess 82aX. It has become like.

When seated, the engagement pin 81aX and the recess 82aX are disengaged, but the engagement pin 81aX and the recess 82aX engage with each other with some resistance, and the lock is not released immediately after seating. Is designed to be unlocked when the resistance is reduced by moving a little.

That is, the control mechanism 8X can be said to be an automatic stopper mechanism at the time of leaving / seating, which switches the locked state of the seat 5 between when the seat is left and when the seat is seated.

Next, the guide hole 34 shown in FIG. 3 will be described. Even if the rail plate 31 that is the plate material PM is made thicker or another member is attached to the rail plate 31 in order to provide the guide hole 34 in order to secure the pressure receiving area, the number of parts and the cost are not necessarily increased. It does not lead to improvement in strength and durability.

Therefore, in the present embodiment, as shown in FIG. 27, a flange portion 31b is provided on the plate material PM of the front-rear swinging portion 3 which is a movable portion provided with the guide hole 34, that is, the vertical surface 31a of the rail plate 31, and the flange portion 31b is provided. A guide surface 31b1 for moving the bearing 45a, which is the rolling element 45, is provided at a position extending in the lateral direction of the 31b, that is, in the horizontal direction in the mounted state.

The guide surface 31b1 has a lateral dimension w1 larger than the thickness t1 of the rail plate 31 which is a plate material PM, and is integrally formed with the rail plate 31 by metal. As shown in FIG. 3, the flange portion 31b has a flange portion 31b. It has a shape that goes around the circumference of the guide hole 34 that opens on the vertical surface.

The flange portion 31b of this embodiment is formed by plastically deforming the plate material PM around the guide hole 34, and specifically adopts burring processing. In general, burring is performed by making a pilot hole in the plate material, fixing the circumference of the pilot hole with a jig, and pressing with a tool larger than the pilot hole in that state to raise the edge of the pilot hole and make it a flange part. Generally, it forms a cylindrical flange, and it is only used for tap hole processing and the like, and there has never been an idea of guiding a rolling element.

Therefore, in this embodiment, from a new point of view, when forming an asymmetrical hole as shown in FIG. 28A, more specifically, a guide hole 34 extending with a substantially constant width, the shape of the guide hole 34 is formed. Corresponding to, as shown in FIG. 28 (b), a pilot hole 34x slightly smaller than that is drilled, and the periphery of the pilot hole 34x is fixed with a jig 34Z along the shape of the guide hole 34, and in that state. It is pressed with a tool 34Y that is larger than the pilot hole 34x and corresponds to the inner peripheral shape of the guide hole 34. As a result, as shown in FIG. 27, a flange portion 31b extending in the lateral direction from the vertical surface 31a via the R portion is formed over the entire circumference of the guide hole 34, and the flange portion 31b facing in the lateral direction is substantially formed. It becomes a pressure receiving area. The lateral dimension of the guide surface 31b1 is made substantially uniform over the entire circumference.

In selecting the processing means for the guide hole 34, it was a condition that the guide surface 31b1 was smooth, that the guide surface 31b1 had strength, and that the processing cost was low. We have also tried fine blanking and other processing, but even in fine blanking, which is relatively likely to be adopted, although it is excellent in forming a smooth guide surface, it is equivalent to a plate material in order to obtain strength. It was found that the burring process was extremely suitable for this because it required a thickness and was not suitable for the cost and could not be adopted, and other processes did not satisfy these conditions.

However, in the burring process, if the shortest distance dimension D from the guide hole 34 to the nearest edge of the plate material PM is short, the plate material PM is deformed during processing or under the load during processing. Therefore, in this embodiment, as a result of trying various tests, as a condition for obtaining a stable shape, the shortest dimension D (see FIG. 28) from the guide hole 34 to the edge of the plate material PM at an appropriate position is 2. It has been found that it is necessary and sufficient to set at least 15 mm or more for a thin plate of ~ 6 mm.

The flange portion 31b formed in this way extends outward from the pair of rail plates 31 and 31 in the left-right direction as shown in FIG. 27 when viewed from the entire chair, and rolls. The guide surface 31b1, which is a surface, is formed on the outside of the rail plate 31. Further, in order to alleviate the impact caused by the collision with the bearing 45a which is the rolling element 45, one end (front end or rear end) of the guide hole 34 is formed with a so-called shockless portion having a change in the radius of curvature. As the bearing 45a approaches the end portion by the operation of the seat 5, the operation speed of the seat 5 is attenuated by controlling the center of gravity of the seat 5 to be raised. The burring flange portion 31b1 is designed to withstand the impact at this time.

Further, in the region below the guide hole 34, when the left-right support state of the front-rear swing portion 3 with respect to the left-right swing portion 4 becomes unbalanced, the bearing 45a which is the rolling element 45 is placed on the lower side of the guide hole 34. It is in contact with the region to support it, and the flange portion 31b contributes to the load support at that time.

Generally speaking, as shown in FIG. 28C, the flange portion 31b has an upper first flange region A1 that supports the front-back movement of the bearing 45a, which is a rolling element 45, and a back 6 during the back-and-forth movement of the seat 5. The second flange region A2 on the front side that supports the portion where the bearing 45a, which is the rolling element 45, reaches the front end of the guide hole 34 when leaning against the ground, and the rolling element 45 when the seated person takes a forward leaning posture. The bearing 45a is provided with a third flange region A3 on the rear side that supports a portion where the bearing 45a reaches the rear end of the guide hole 34, and is a rolling element 45 when the left and right support states become unbalanced. The lower fourth flange region A4 that supports the bearing is provided. Such a structure is the same even if the guide hole 34 is formed on the support portion side and the bearing 45a, which is the rolling element 45, is arranged on the movable portion side.

As described above, the guide hole 34 is formed on the vertical surface of the movable portion or the support portion of the chair and moves under a seating load, and the movable portion is a guide by the rolling element 45 and the guide hole 34. It is supported by the support part at two places before and after including the structure. In the present embodiment, the other movable part of the chair is supported by the link arm LA, and one of the front and rear support structures is composed of the rolling element 45 and the guide surface 31b1 described above, and the other is a support structure different from this, that is, this. The embodiment has a link structure.

Next, the support mechanism of the back 6 will be described. As shown in FIGS. 2, 14, 30, and 29, the chair has a back 6 arranged behind the seat 5, and the back frame 61 supports the backrest 62 via an operating mechanism 6M. A back inner cover 63 is attached to the back frame 61, an opening 63a is provided in the back inner cover 63, and the backrest 62 is operably supported by the back frame 61 through the opening 63a. ing.

The backrest 62 has a cushion placed on the front surface of the back plate 62a and is entirely covered with upholstery. It is supported by the back support portion 61a at the upper end of the back frame 61 via the operation mechanism 6M.

The operation mechanism 6M has a base portion 64 fixed or integrally formed on the back plate 62a constituting the backrest 62 and having an elastic member 65 arranged on the back surface side, and a base portion 64 arranged at a position adjacent to the base portion 64 and tapered to the back surface side. A tilt portion 65 having a guide portion 65a recessed in a shape and having an opening in the center in the front-rear direction, and a convex guide portion 66a corresponding to the guide portion 65a on the front side thereof, and the guide portion 66a is the guide portion 65a. As shown by an arrow J in FIG. 29, the tilt portion 65 is provided with a presser foot 66 fixed to the base portion 64 through the opening of the tilt portion 65, and the tilt portion 65 is shown in FIGS. 29 and 30. As shown by an arrow K, the back inner cover 63 is formed by penetrating the opening of the back inner cover 63 and pulling and fixing the back frame 61 to the back support portion 61a on the upper end side with a screw. That is, as shown in FIG. 31, the presser foot 66 is fixed to the base portion 64 with the tilt portion 65 sandwiched therein, thereby forming a part of the base portion 64 integrally with the base portion 64, and the tilt portion. The 65 is allowed to float in the gap between the base portion 64 and the presser foot 66, but in the floating, it is necessary to compress the elastic body 67 interposed between the tilt portion 65 and the base portion 64 against the elastic force. It is configured to be. A force acting on the guide portion 65a of the tilt portion 65 in the direction of being constantly fitted into the guide portion 66a of the presser foot 66 by the elastic body 67.

More specifically, as shown in FIG. 32, the concave guide portion 65a of the tilt portion 65 is almost partially elliptical mortar-shaped having at least one valley line 65ax (two in this embodiment). The convex guide portion 66a of the presser foot 66 has a chevron shape having at least one ridge line 66ax (two in this embodiment) that gently fits the guide portion 66a, and the valley line 65ax and the ridge line 66ax can be fitted to each other. Shape. The convex guide portion 66a resembles a shape obtained by cutting a part of an ellipsoidal sphere, and a ridge line 66ax is formed at a portion where the guide surface 66a and the guide surface 66a intersect on the long axis side of the ellipsoidal sphere. A valley line 65ax is also formed at a portion where the guide surface 65a and the guide surface 65a intersect at a corresponding position on the concave guide portion 65a. This is because the sphere and the spherical seat do not have directionality and the positioning function cannot be performed. In that sense, the convex guide portion 66a and the concave guide portion 65a are not limited to the mortar-shaped shape and the ellipsoidal sphere shape as long as they have irregular shapes in which the directionality at the time of fitting is uniquely determined. However, in view of the smoothness of the guide, the guide portions 66a and 65a need to be formed of smooth continuous surfaces. The ridge line 66ax and the valley line 65ax are provided in order to enhance the positioning function at the time of fitting.

Urethane is used for the elastic body 67 in this embodiment, and as shown in FIG. 29, it is arranged from the left and right corners to the upper edge portion in the upper half of the base portion 64 having a rectangular plate shape. As for the thickness dimension, as shown in FIG. 31, the presser foot 66 is attached to the base portion 64, the tilt portion 65 is attached to the back support portion 61a of the back frame 61, and the guide portion 66a of the presser foot 66 and the guide portion 65 are guided. It is set so that the portion 65a is in a state of being fitted and appropriately compressed. Considering that the load is applied above the center of the operating mechanism 6M when leaning against the backrest 62, the elastic body 67 is not provided in the lower half of the base portion 64, which has little chance of substantially functioning. , It does not prevent the elastic body 67 from being provided at this position.

FIG. 33 shows a backward tilted state when a load is applied to the upper part of the back 6, and FIG. 34 is a plan cross section thereof. Further, FIG. 35 shows a turning motion of the back 6 when the seated person twists the body.

That is, the backrest 62 is arranged in a positional relationship in which it moves against the elastic reaction force in the rearward direction and the turning direction while being supported by the elastic body 67, and the elastic body 62 is arranged according to the amount of turning movement in the front-back and left-right directions. The 67 is deformed back and forth and left and right, and the backrest 62 is configured to have a large reaction force to return to the neutral position. The turning direction includes a front-view left-right direction as shown in FIG. 35, and further a front-view clockwise or counterclockwise turning movement.

The guide portion 66a of the presser foot 66 constituting the base portion 64 and the guide portion 65a on the tilt portion 65 side are pressed against each other by the elastic body 67, and the guide portions 66a and 65a are brought into the reference position shown in FIG. 31 according to the shape of the guide portions 66a and 65a. Be guided and stand still. Then, when the pressure contact is loosened due to the compression of the elastic member 67 due to the load applied by the pressure received from the seated person, the guide portion 65a of the tilt portion 65 and the guide portion 66a of the presser foot 66 constituting the base portion 64 As shown in FIGS. 33, 34, and 35, at least a part of the backrest 62 is separated from each other so that the backrest 62 can move freely, and the base portion 64 and the tilt portion 65 change relative to the reference position according to the degree of pressure reception. When the load is removed, the operating position is automatically returned to the neutral position in FIG. 31 where the ridge line 66ax and the valley line 65ax match along the guide portions 66a and 65a. At that time, the backrest 62 is configured so that the gap SP between the guide portions 66a and 65a expands as the back frame 61 moves in the rear direction, and as a result, the turning range in the left-right direction becomes large. The return reaction force when the is removed is configured to increase according to the amount of turning movement in both the left and right directions.

As shown in FIG. 36, the base portion 64 and the tilt portion 65 are provided with engaging portions 64b and 65b that regulate the relative movement of the base portion 64 and the tilt portion 65 in cooperation with the guide portions 65a and 66a. be. The base portion 64 has a vertical wall 64c on the edge thereof, and a window 64b1 serving as an engaging portion 64b is opened in the vertical wall 64c in a rectangular shape. On the other hand, the tilt portion 65 is formed with an L-shaped claw 65b1 serving as an engaging portion 65b at a position displaced downward on the front side. Then, the base portion 64 and the tilt portion 65 are assembled in a state where the claw 65b1 is loosely fitted in the window 64b1, and the movable range of the tilt portion 65 with respect to the base portion 64 is within a range in which the claw 65b1 can move in the window 64b1. It is regulated. When the range of motion is regulated, part of the backrest load is also supported at the regulated area.

As described above, the left-right turning motion of the back 6 occurs with respect to the back frame 61, and the seat 5 is attached to the front-rear swinging portion 3 to which the back frame 61 is attached. Therefore, the back frame 61 and the seat 5 are viewed from the front. Although it swings integrally in the left-right direction, the backrest 62 further separates from the left-right turning motion of the seat 5 and the back frame 61 and moves differently.

In this embodiment, the base portion 64 is attached to the backrest 62 and the tilt portion 65 is attached to the back frame 61 side, but the base portion 64 is attached to the back frame 61 side and the tilt portion 65 is attached to the backrest 62 side. May be configured.

Next, the front support mechanism of the seat will be described.

As described above, this chair supports the seat 5 so as to be swingable back and forth and left and right with respect to the support base 2, but the seated person seated on the chair that swings back and forth and left and right is left and right depending on the posture. The feeling of pressure on the thighs of the legs changes unbalanced. Further, in this chair, the back 6 is provided behind the seat 5 so that the back 6 can be tilted backward, and when the back 6 is tilted backward, the seat 5 interlocks with each other to perform an operation in which the front portion is relatively raised and the rear portion is lowered. There is a possibility that anxiety and instability may occur due to the feeling of pressure on the thighs of the legs when leaning backward and the floating of the legs.

Therefore, as shown in FIGS. 38, 37 and 39, this chair is provided with a deformed portion 5X that changes its shape in the vertical direction by receiving a seating load on the front portion 5f of the seat 5.

The deformed portion 5X is provided at a position where the weight of the leg of the seated person is received, and is configured to deform downward when the weight of the leg is received and to return upward when the weight of the leg is removed.

Specifically, as shown in FIG. 38, the seat 5 has a cushion material 54 arranged on the seat inner shell 53, covered with an upholstery (not shown), and the seat outer shell 51 is attached below the seat inner shell 53. It is a thing. The seat inner shell 53 is configured by connecting the rear portion 53a and the front portion 53b with a resin hinge portion 53c so that the front portion 53b elastically deforms with respect to the rear portion 53a with the resin hinge portion 53c as a boundary. It has become. Along with this, the cushion material 54 is also deformed, and these portions form the deformed portion 5x.

Then, the seat outer shell 51 is fixed to the front-rear swinging portion 3, and the rear portion 53a of the seat inner shell 53 is attached above the seat outer shell 51. As a result, the deformed portion 5x including the front portion 53b of the seat inner shell 53 is deformed toward the seat outer shell 51.

In this embodiment, the front seat cover 55 is attached to the front portion 53b, which is the deformed portion 5x of the seat inner shell 53, so as to sandwich the seat outer shell 51. In FIG. 15, it seems that the front seat cover 55 is attached to the front part of the seat outer shell 51, but in reality, as shown in FIGS. 39 and 40, it is not under the front part of the seat outer shell 51. The front seat lower cover 55 is arranged in the connected state and is connected to the deformed portion 5x of the upper seat inner shell 53. As shown in FIG. 15, the front seat lower cover 55 has left and right dimensions substantially corresponding to the left and right dimensions of the front portion 53b of the seat inner shell 53, and the base end 55a is sandwiched between the seat outer shells 51. It is attached to the engaged portion 53b1 (see FIGS. 39 and 40) set in the front portion 53b of the seat inner shell 53, and has a shape in which the rear end 55b side extends rearward and downward along the seat outer shell 51.

Compression springs 56, which are elastic bodies, are arranged at two positions on the left and right sides of the front portion of the seat outer shell 51 at positions where they are compressed with the front portion 53b of the seat inner shell 53.

Then, when the deformed portion 5x on the seat inner shell 53 side approaches the seat outer shell 51 as shown in FIGS. 39 to 40, that is, the deformed portion 5x of the seat inner shell 53 deforms downward while compressing the compression spring 56. At that time, an appropriate portion of the front portion 53b of the seat inner shell 53 abuts on the upper surface of the front portion of the seat outer shell 51 (contact point T1), and conversely, the deformation portion 5x is deformed by the compression spring 56 in FIGS. 40 to 39. When the front portion 53b of the seat inner shell 53 moves upward as shown in the above, the front seat lower cover 55 abuts on the front lower surface of the seat outer shell 51 (contact point T2). I have to. That is, the deformation range of the deformed portion 5x of the seat inner shell 53b is restricted both downward and upward.

Here, as shown in FIGS. 37 and 39, the resin hinge 53c has a corrugated plate shape in which several irregularities are connected, and the deformed portion 5x is biased to the left side region and the right side region of the seat 5. Depending on the load, the structure is such that not only the vertical direction but also one of the left and right directions of the seat 5 is higher than the other, which is likely to cause torsional deformation.

As shown in FIGS. 1 and 2, the chair of the present embodiment has a fixed elbow portion 91 attached to the elbow attachment portion 23 of the support base portion 2 so as to bypass the seat 5 and extends upward. Even if 5 swings back and forth and left and right, the fixed elbow portion 91 is in a fixed position so as not to interfere with the seat 5. Further, below the seat 5, a movable cover mechanism 92 in which a plurality of covers are combined is arranged so as to blindfold the front-rear swinging portion 3 and the left-right swinging portion 4 without interfering with the relative movements.

As described above, in the chair of the present embodiment, the front portion 5f of the seat 5 is provided with the deformed portion 5X that changes its shape in the vertical direction in response to the seating load, and the seat 5 is moved back and forth and left and right with respect to the support base portion 2. It is supported so that it can swing. In this way, in combination with the deformation operation of the deformed portion 5X provided on the front portion 5f of the seat 5, the seat 5 swings back and forth and left and right with respect to the support base 2, thereby supporting the seat 5. Can be synergistically relieved of pressure on the thighs and buttocks while maintaining proper.

Further, the deforming portion 5X is provided at a position where the weight of the leg of the seated person is received, and is configured to deform downward when the weight of the leg is received and to return upward when the weight of the leg is removed. Since the deformed portion 5X is deformed according to the weight, it is possible to provide appropriate support according to the pressure contact condition of the legs.

Further, the back 6 is provided behind the seat 5 so that the back 6 can be tilted backward, and when the back 6 is tilted backward, the seat 5 is configured to perform an operation in which the front portion 5f is relatively raised and the rear portion is lowered. Therefore, even in a chair in which the seat 5 swings back and forth and left and right with respect to the support base 2, it is possible to realize a state in which the legs are not pressed when the back seat tilts backward. Further, when the front portion 5f of the seat 5 is lowered when the seat 5 is tilted backward, the legs do not float, so that a sense of security and a sense of stability can be obtained.

Further, since the deformed portion 5X is twisted and deformed according to the eccentric load received on the left side region and the right side region of the seat 5, the load applied from the left and right legs to the front portion 5f of the seat 5 is different in the chair swinging left and right. Even if a case occurs, it can be effectively dealt with by torsional deformation.

Further, the seat 5 is formed by arranging a cushioning material 54 on the seat inner shell 53, and the seat inner shell 53 is provided so as to be elastically deformable between the rear portion 53a and the front portion 53b, and the front portion 53b is provided. The deformed portion 5X is used, and if the seat inner shell 53 is used as the deformed portion 5X in this way, the backup property is excellent and the deforming operation is stable.

Further, since the range when the deformed portion 5X including the seat inner shell 53 is deformed in the vertical direction is restricted, it is possible to prevent the deformed portion 5X including the seat inner shell 53 from being inadvertently moved.

Further, the seat outer shell 51 is provided at a distance from the outside of the seat inner shell 53 so that the deformed portion 5X at the front portion of the seat inner shell 53 can be deformed toward the seat outer shell 51, and the seat outer shell is formed. The front seat cover 55 is attached to the deformed portion 5X of the seat inner shell 53 so as to sandwich the 51, and when the deformed portion 5X of the seat inner shell 53 is separated from the seat outer shell 51 by a predetermined distance, the front seat cover 55 sits. Since the outer shell 51 is in contact with the outer shell 51, the deformation range can be regulated and the internal structure can be blinded only by attaching the front seat lower cover 55 to the deformed portion 5X of the seat inner shell 53.

Further, since the compression springs 56 are interposed at least at two positions on the left and right between the seat outer shell 51 and the deformed portion 5X of the seat inner shell 53, the seat 5 swings left and right, and the degree of leg rise is also different on the left and right. However, the reaction force increases according to the weight of the legs to provide appropriate support, and the initial reaction force of the compression spring 56 can be appropriately set.

Although one embodiment of the present invention has been described above, the specific configuration of each part is not limited to the above-described embodiment.

For example, those shown in FIGS. 41, 42, and 43 also support the seat 105 so as to swing back and forth and left and right with respect to the support base 102, and receive a seating load on the front portion of the seat 105 in the vertical direction. The deformed portion 105X that changes the shape is provided, and the deformed portion 105X is provided at a position that receives the weight of the leg of the seated person. It is configured to return upward.

In the illustrated example, a regulating member 105Z for regulating the deformation range is provided below the front portion of the seat shell 151, and the regulating member 105Z is lowered as the back seat tilts backward in conjunction with the front-rear movement of the back seat. The deformation range of the deformed portion 105X is increased.

In this way, since the bending range of the front part of the seat increases as the back leans backward, the legs are not pressed and the legs do not float when leaning backward, so that the regulation position changes according to the posture. Appropriate support can be provided, and a sense of security and stability can be obtained.

The regulation member 105Z is configured to support the seat shell 151 when it is deformed against the elastic force by receiving a seating load, and is suspended from the elastic force until it is supported by the support portion. The legs can be supported at the meeting point. Therefore, the leg can be supported at the point of suspension with the elastic force until it is supported by the support portion.

Specifically, the regulation member 105Z is connected to the front-rear swinging portion 103 that supports the back seat so as to be movable back and forth via the interlocking mechanism 105M. A left-right swing portion 104 is supported on the support base 102 so as to be swingable to the left and right, and the front-rear swing portion 103 is front-rear and rear-rear with respect to the left-right swing portion 104 via a guide hole 134 and a bearing 145a which is a rolling element 145. It is arranged so that it can swing. The regulating member 105z is pivotally attached to a part of the front-rear swinging portion 103 via a shaft S101 at its base end, and a shaft is attached to the tip of a bracket 150 engaged with the rolling element 145 or its shaft in the middle via a guide hole 150z. It is worn. The behavior of the regulating member 105z can be appropriately defined by the shape of the guide hole 150z.

Further, as shown in FIGS. 44 and 45, the deformed portion of the seat may be supported according to the left and right loads, and the bending hardness thereof may be increased or decreased according to the physique. It may be configured as. In the seat inner shell 251 shown in FIGS. 44 and 45, the rear portion 251b engages with the leaf springs 251X and 251Y arranged at least at two positions on the left and right sides with the resin hinge 251a as a boundary, and the front portion 251c It is configured to be in contact with this, and the leaf springs 251X and 251Y are deformed independently, so that the deformed portion 205X can be deformed while receiving a reaction force corresponding to the left and right loads. Therefore, the spring can be easily arranged by arranging the spring adjacent to the seat inner shell 251.

In this case, the seat inner shell 251 and the leaf springs 251X and 251Y are supported by the base 251Z so that the seat inner shell 251 can move back and forth relative to the leaf springs 251X and 251Y, and the leaf spring is more than the rear part. Although the front portion is wide, the distance D from the engagement position of the rear portion 251b with respect to the leaf spring to the impact position of the front portion 251c is kept constant. Therefore, depending on the relative positions of the seat inner shell 251 and the leaf springs 251X and 251Y, the deformation reaction force of the front portion 251c and thus the deformation portion 205X can be changed, and the larger the body, the larger the seating area in the depth direction. The effect of increasing the reaction force of the deformed portion 205X is achieved, and the reaction force increases according to the weight of the leg, enabling appropriate support.

Other configurations can be modified in various ways without departing from the spirit of the present invention.

2 ... Support base 5 ... Seat 5X ... Deformation part 51 ... Seat outer shell 53 ... Seat shell (seat inner shell)
54 ... Cushion material 55 ... Front cover (front under-seat cover)
56 ... Compression spring 105 ... Seat 102 ... Support base 105X ... Deformation part 151 ... Seat shell 105Z ... Regulatory member 205X ... Deformation part 251 ... Seat inner shell 251b ... Rear part 251c ... Front part 251X ... Leaf spring 251Y ... Leaf spring

Claims (8)

In a chair in which the front part of the seat is provided with a deformed part that changes its shape in the vertical direction in response to a seating load, and the seat is swingably supported back and forth and left and right with respect to the support base .
The seat is formed by arranging a cushion material on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion.
The range when the deformed part of the seat shell is deformed in the vertical direction is regulated.
An outer shell is provided on the outside of the seat shell so that the deformed portion at the front portion of the seat shell can be deformed toward the outer shell, and the deformed portion of the front seat shell is sandwiched between the outer shell. A chair characterized in that a front cover is attached so that the front cover comes into contact with the outer shell when the deformed portion of the seat shell is separated from the outer shell by a predetermined distance. In a chair in which the front part of the seat is provided with a deformed part that changes its shape in the vertical direction in response to a seating load, and the seat is swingably supported back and forth and left and right with respect to the support base.
The seat is formed by arranging a cushion material on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion.
The seat shell has a rear portion that is engaged with leaf springs provided at at least two locations on the left and right, and a front portion that is elastically contacted.
A chair characterized in that the deformation reaction force of the deformed part can be changed by the relative position of the seat shell and the leaf spring. In a chair in which the front part of the seat is provided with a deformed part that changes its shape in the vertical direction in response to a seating load, and the seat is swingably supported back and forth and left and right with respect to the support base.
The seat is formed by arranging a cushion material on the seat shell, and the seat shell is provided so as to be elastically deformable between the rear portion and the front portion, and the front portion is a deformable portion.
A regulating member that regulates the deformation range is provided below the front part of the seat shell, and in conjunction with the front-back movement of the back seat, the regulating member lowers relatively downward with respect to the front part of the seat shell as the back seat tilts backward. , A chair characterized by being configured to increase the deformation range of the deformed part. The chair according to claim 3, wherein the regulating member is configured to support the seat shell when it is deformed against an elastic force by receiving a seating load. The chair according to claim 3 or 4, wherein the regulating member is connected to a front-rear support portion that supports the back seat so as to be movable back and forth via an interlocking mechanism. A claim that the deformed portion is provided at a position that receives the weight of the leg of the seated person, deforms downward when the weight of the leg is received, and returns upward when the weight of the leg is removed. The chair according to any one of 1 to 5. Any of claims 1 to 6, wherein the back is provided behind the seat so that the back can be tilted backward, and when the back is tilted backward, the seat is interlocked to perform an operation in which the front portion is relatively raised and the rear portion is lowered. The chair described in the crab. The chair according to any one of claims 1 to 7, wherein the deformed portion is twisted and deformed according to an eccentric load applied to a region on the left side and a region on the right side of the seat.

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