chair

Abstract

To provide an unprecedented chair in which a seat can follow up free movement in all directions of a seated person, in which structure is simple and load can be reduced in the load balancing movement of the seated person, and in which it can properly support the movement of changing a posture stably and continuously.SOLUTION: A movement mechanism is composed so that an upper base part 31 can rock at 360° directions for a lower base part 32. In a chair with a seat installed on the upper base part 31, as a separate mechanism from the movement mechanism, there is provided damper mechanism DM by which the upper base part 31 and the lower base part 32 can be actuated to a consecutive position in following up the movement of 360° directions.SELECTED DRAWING: Figure 14

Description

[Technical Field]

[0001] The present invention relates to a chair suitable for use in an office or the like, in which the seat can be moved forward, backward, left, right and diagonally. [Background technology]

[0002] BACKGROUND ART Chairs in which the seat can be moved in forward, backward, left, right and diagonal directions are known, for example, as disclosed in Patent Documents 1 and 2.

[0003] Patent Document 1 describes a configuration in which a plurality of fluid bags are connected by flow paths, and the seat is tilted by the movement of air.

[0004] Patent Document 2 describes a configuration in which a plurality of independent air cushions are fitted into a recess in the seat and covered with a covering member, thereby providing cushioning when seated. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-82521 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-297319 Summary of the Invention [Problem to be solved by the invention]

[0006] However, in the configurations of Patent Documents 1 and 2, although the seat can move freely under the cushioning effect, conversely the seat has too much freedom of deformation and is unable to provide a so-called support, so rather than the seat following the movements of the occupant, the occupant ends up following the movements of the seat, making this unsuitable for supporting the occupant's movements of continuously changing posture while balancing the load.

[0007] One possible solution to this problem is to configure the upper base part, which receives the seating load, to move 360° along a predetermined trajectory relative to the lower base part that supports the upper base part via a moving mechanism, and to attach the seat to the upper base part.

[0008] However, even if this configuration alone results in a certain degree of regularity in the movement, the movement mechanism alone still gives the seat too much freedom, which can place a heavy burden on the user as they have to support the movement of their own weight when changing posture.

[0009] The present invention has been made with a focus on these problems, and aims to realize a chair unlike any other in the past, in which the seat can follow the free forward, backward, left, right and diagonal movements of the occupant, has a simple structure, reduces the burden on the occupant when balancing their weight, and can appropriately support stable and continuous posture changes. [Means for solving the problem]

[0010] In order to achieve the above object, the present invention takes the following measures.

[0011] That is, the chair of the present invention is configured with a movement mechanism that allows the upper base part to swing in 360° directions relative to the lower base part, and in a chair with a seat attached to the upper base part, a damper mechanism that can operate in response to the 360° movement is provided at the position connecting the upper and lower base parts as a mechanism separate from the movement mechanism. The damper mechanism is configured to include a hole provided in one of the upper base portion or the lower base portion, a cylindrical member provided in the other base portion and inserted into the hole, and a friction material disposed between the hole and the cylindrical member, the hole having a tapered shape that opens upward, and the cylindrical member being able to pass through the hole. It is characterized by:

[0012] With this configuration, the upper base can follow the free forward, backward, left, right, and diagonal movements of the seated person using the movement mechanism, making it easier for the seated person to balance their weight while supporting it, allowing for stable and continuous posture changes.In particular, since a damper mechanism is provided as a separate mechanism from the movement mechanism rather than providing resistance to the movement mechanism itself, the effectiveness of the damper mechanism can be adjusted without changing the basic performance of the movement mechanism itself. This makes it possible to make the damping effect uniform and easy to adjust.

[0013] A specific embodiment of the moving mechanism includes a rolling surface that is curved on at least one of the facing surfaces of the upper base portion and the lower base portion, and is configured so that a seat provided on the upper base portion oscillates when the upper base portion rolls relative to the lower base.

[0014] Such a damper mechanism is particularly suitable when applied to a chair that is configured so that, regardless of the direction of movement of the seat through 360° from the reference position, the upper base portion tilts downward in the direction of movement as the seat moves away from the reference position.

[0015] In order to increase design freedom and achieve an appropriate damping effect, it is desirable that the damping mechanism be arranged at multiple locations around a predetermined center of the seat and be operable in at least one or both directions of expansion and contraction of the distance between the upper base portion and the lower base portion.

[0016] In order to allow the damper mechanism to respond appropriately to the free movement of the seat, it is desirable that the damper mechanism be located between the upper base portion and the lower base portion and connected to at least one of the base portions by a non-directional joint.

[0018] In order to ensure stable operation, it is desirable that the relative movement of the damper mechanism be a sliding movement of the hole and friction material along the longitudinal direction of the cylindrical member.

[0019] A preferred embodiment, taking into account the damper mechanism, is one in which an elastically deformable elastic member is provided between the upper base portion and the lower base portion, and the upper base portion is configured to move between the upper base portion and the lower base portion while compressing the elastic member.

[0020] Another preferred embodiment, taking into account the damper mechanism, is to interpose a return spring between the upper base portion and the lower base portion to return them toward a predetermined reference position.

[0021] Another preferred embodiment in terms of compatibility with the damper mechanism is one in which a gravity return mechanism is provided between the upper and lower base parts, which generates a return force to the reference position by raising the center of gravity of the movable part including the upper base part in response to movement of the upper base part from the reference position. [Effects of the Invention]

[0022] Because of the configuration described above, the present invention makes it possible to provide a new and useful chair that can follow the free movement of a seated person in all directions, forward, backward, left, right and diagonally, and can appropriately support the seated person's movements as they continuously change posture while balancing the load. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a perspective view of a chair according to an embodiment of the present invention; [Figure 2] The same front view. [Figure 3] Right side view of the same. [Figure 4] FIG. 2 is a perspective view of the chair with part of the seat omitted. [Figure 5] Same plan view. [Figure 6] 2 is a diagram showing the relationship between the moving mechanism and the seat and legs that constitute the chair. FIG. [Figure 7] FIG. [Figure 8] FIG. [Figure 9] FIG. [Figure 10]FIG. [Figure 11] FIG. 11 is a further exploded top perspective view of FIG. 10. [Figure 12] FIG. [Figure 13] 3A and 3B are diagrams illustrating opposing rolling surfaces that constitute a movement mechanism. [Figure 14] FIG. 10 is a diagram showing an assembly structure of a damper mechanism attached to a moving mechanism. [Figure 15] FIG. 10 is a diagram showing the assembly structure of a return spring attached to the moving mechanism. [Figure 16] 8 is a cross-sectional view taken along line XVI-XVI in FIG. 7. [Figure 17] FIG. [Figure 18] FIG. [Figure 19] 16A and 16B are cross-sectional views showing a state in which the figure is tilted forward. [Figure 20] 16A and 16B are cross-sectional views corresponding to those shown in FIG. 16A and FIG. [Figure 21] FIG. 8 is a cross-sectional view taken along line XXI-XXI in FIG. [Figure 22] FIG. [Figure 23] 22 is a cross-sectional view corresponding to FIG. 21 when tilted left and right. [Figure 24] FIG. 10 is a diagram showing the assembly structure of a pin attached to the movement mechanism. [Figure 25] 5A and 5B are diagrams showing the mounting structure of the cover member. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0025] Figures 1 to 3 show the appearance of a chair according to this embodiment, and Figures 4 and 5 show views with part of the seat 1 omitted. As shown in these figures, this chair is movably supported between the seat 1 and legs 2 by a movement mechanism 3, with the back 4 attached so that it moves integrally with the seat 1, and armrests 5 attached so that they do not move integrally with the seat 1 and back 4. Figures 17 and 18 show the state in which the seat 1 has moved in the forward / backward direction, and Figure 22 shows the state in which the seat 1 has moved in the left / right direction.

[0026] The seat 1 is made by covering the periphery of a seat body 11 with upholstery 12, and is attached to a movement mechanism 3 via a seat shell 13. The seat shell 13 has a seat inner shell 131 attached to the underside of the seat body 11, and a seat outer shell 132 that backs up the seat inner shell 131 and connects it to the movement mechanism 3.

[0027] The legs 2 have casters 22 at the lower ends of the leg blades 21, and leg support columns 23 stand upright from the center of the leg blades 21, with the seat 1 rotatably attached to the upper ends of the leg support columns 23. The leg support columns 23 are made extendable and retractable by a gas spring mechanism GS (shown in Figure 6) incorporated inside. Reference numeral 24 in the figure denotes an operating lever for operating the operated part 23a of the gas spring mechanism GS.

[0028] As shown in Figures 6 to 11, the movement mechanism 3 is configured by arranging an upper base portion 31 and a lower base portion 32 in positions facing each other, attaching the lower base portion 32 to the leg support 23, and attaching the seat 1 to the upper base portion 31. An elastic member 33 is interposed between the upper base portion 31 and the lower base portion 32. The periphery of the elastic member 33 is covered with a cover member 6 as shown in Figures 19, 20, 23, and 25, but the cover member 6 is omitted in other figures. The elastic member 33 is also omitted in Figures 10, 13, etc.

[0029] The moving mechanism 3 supports the upper base portion 31 relative to the lower base portion 32 so that it can move in the front-to-back direction as shown in Figures 19 to 21, and in the left-to-right direction as shown in Figures 21 and 23, and also in a 360° direction including these.

[0030] As shown in Fig. 10, the upper base portion 31 is configured to include a disk-shaped seat support 311 and a disk-shaped upper base plate 312 attached below the seat support 311. Although the seat support 311 shown in Figs. 7 to 10 is shown as a single unit, in reality it is molded integrally with the surrounding seat outer shell 132 from resin, as shown in Fig. 5. High nuts 312s are provided on the upper base plate 312, and boss holes 311s are provided at corresponding positions on the seat support 311. With the lower surface of the seat support 311 abutting against the upper surface of the high nuts 312s, the upper base plate 312 and the seat support 311 are connected from above by bolts (not shown) inserted through these nuts.

[0031] As shown in FIG. 10 , the lower base portion 32 includes a disk-shaped support base 321 attached to the upper end of the leg support 23 and a disk-shaped lower base plate 322 attached to the support base 321. Reference numeral 322y in the figure denotes an engagement claw provided on the lower base plate 322, which engages with the peripheral edge of the support base 321 to unite the lower base plate 322 and the support base 321. As shown in FIGS. 6 and 9 , a leg mounting portion 321a for fitting the leg support 23 is provided on the underside of the support base 321, and the leg mounting portion 321a is reinforced by radially extending ribs 321b to increase rigidity. An operated portion 23a for operating a gas spring is provided at the upper end of the leg support 23. When the leg support 23 is inserted into the leg mounting portion 321, the operated portion 23a is positioned so that it can be operated by the operating unit 24.

[0032] 13 is a schematic diagram of the rolling surfaces that constitute the movement mechanism 3, with the elastic member 33 omitted. As shown in this figure, the opposing surfaces of the upper base portion 31 and the lower base portion 32 (in this embodiment, the opposing surface 312a of the upper base plate 312 that constitutes the upper base portion 31 and the opposing surface 322a of the lower base plate 322 that constitutes the lower base portion 32) form rolling surfaces that roll against each other. In this embodiment, the rolling surface 322a of the lower base plate 322 is formed as a flat surface, and the rolling surface 312a of the upper base plate 312 is formed as a curved surface that bulges toward the rolling surface 322a of the lower base plate 322, and the contact area between the upper base portion 31 and the lower base portion 32 changes with the rolling motion as shown by the imaginary lines in the figure. Of course, the lower base plate 312 side may be a curved surface and the upper base plate 322 side may be a flat surface, or both the upper base plate 312 side and the lower base plate 322 side may be curved surfaces.

[0033] The curved surface is substantially partially spherical or has a substantially arcuate cross section, in other words, a bowl shape or a convex R-shape, and the upper base portion 31 can move in all 360° directions, including forward, backward, left, right, and diagonal directions, while rolling on the lower base portion 32. This curved surface can be embodied in various ways, such as a mode in which it curves at a constant curvature even when it moves away from the reference position N, which is the contact position between the base portions 31 and 32 when there is no upper load, a mode in which the curvature changes smoothly as it moves away from the reference position N, a mode in which the curvature is different between the front and back and the left and right, or a mode in which the curvature is different between the front and back.

[0034] As shown in Figures 10 to 12, the upper base plate 312 and the lower base plate 322 form opposing surfaces (rolling surfaces) 312a, 322a that move relative to each other. To conceal the gap between the rolling surfaces 312a, 322a, the upper base plate 312 also serves as an attachment member for attaching a cover member 6, which will be described later with reference to Figure 25. However, for example, in Figures 10 to 12, if the upper base plate 312 and the lower base plate 322 are provided in positions where they do not form opposing surfaces, or if the cover member 6 is attached in a different manner to conceal part of the movement mechanism 3, the lower surface of the seat receiver 311 or the upper surface of the support base 321 can also be used as the opposing surfaces (rolling surfaces). In this case, the upper base plate 312 and the lower base plate 322 themselves may be unnecessary.

[0035] 11 and 12, elastic member 33 is attached with its upper surface 33a and lower surface 33b in contact with rolling surfaces 312a and 322a, respectively, and is made of a resin foam elastic body so that it forms a cylindrical shape when there is no load on it. High-elasticity urethane foam, low-elasticity urethane foam, or the like can be used as the resin foam elastic body. High-elasticity urethane foam provides a cushioning effect by instantly deforming when subjected to external force, while low-elasticity urethane foam provides a delay effect by gradually deforming when subjected to external force.

[0036] In this embodiment, high-elasticity urethane foam is used because it has low temperature dependency and excellent durability. Of course, low-elasticity urethane foam may also be used for the elastic member, and thin materials such as elastic sheets may also be used.

[0037] When the upper base portion 31 receives an upper load and moves in any direction of 360°, including forward, backward, left, right, and diagonal directions, relative to the lower base portion 32, as shown in Figures 19, 20, 23, etc., the rolling surface 312a of the upper base plate 312 moves between the rolling surface 322a of the lower base plate 322, compressing the elastic member 33, and accordingly, the upper base plate 312 tilts downward in the direction of movement. The seat 1 is caused to rock through the upper base portion 31, tilting downward in the direction of movement in accordance with the movement of the seated person.

[0038] Generally, the movement mechanism may be configured to provide a guide mechanism consisting of a cam and follower between the upper and lower base portions, or to connect the upper and lower base portions with a link mechanism. In contrast to these structures, the movement mechanism 3 of this embodiment utilizes rolling surfaces 312a and 322a to achieve movement of the seat 1 that is primarily tilting rather than horizontal movement. The chair of this embodiment, which operates in this manner, is particularly convenient for use in situations where people frequently sit and get up from their seats.

[0039] The curvature of the rolling surfaces 312a, 322a is set so that as the seat moves, the center of gravity G of the seat rises to G' as shown by the solid line to the imaginary line in Figure 13, and these rolling surfaces 312a, 322a form a gravity return mechanism GRM that generates a return force in response to body weight to return the seat 1 to the reference position N, which is the position when there is no upper load.

[0040] 11 and 12, the movement mechanism 3 is equipped with a first connecting member 34 that fixes the upper base portion 31 to the lower base portion 32 so that they do not separate and restricts relative rotation, and a second connecting member 35 that provides a damping function to the movement mechanism 3. The damping function is provided in order to suppress sudden movements of the seat 1, in view of the fact that the movement mechanism 3 of this embodiment operates by rolling and that highly elastic urethane foam, which deforms quickly, is used for the elastic member 33.

[0041] Accordingly, first holes 31P to 33P for inserting pins 341 constituting the first connecting member 34 along the first line L1, and second holes 31Q to 33Q for inserting shafts 351 constituting the second connecting member 35 along the second line L2 are formed in the upper base portion 31, the lower base portion 32, and the elastic member 33. The holes 31P, 32P, 33P, 31Q, 32Q, and 33Q are also referred to as "relief holes" in this specification, in the sense that they prevent the pins 341 and shafts 351 from interfering with the rolling surfaces 312a and 322a and the elastic member 33.

[0042] The first connecting member 34 mainly comprises three pins 341, which are integrated by a flange 342. Each pin 341 is inserted through a first hole 31P in the upper base portion 31 (i.e., the first hole 31P in the seat holder 311 and the first hole 31P in the upper base plate 312), a first hole 33P in the elastic member 33, and a first hole 32P in the lower base portion 32 (i.e., the first hole 32P in the lower base plate 322), and is fastened from below by a bolt (not shown) at a position where it abuts against the support base 321 that constitutes the lower base portion 32. Figure 19 etc. shows this state. The first holes 31P in the seat holder 311 open in three places corresponding to the positions of the three pins 341, while the first hole 31P in the upper base plate 312 is a large hole that can simultaneously accommodate all three pins 341.

[0043] With this structure, for example, the relative position (distance L) between the flange 342 of the first connecting member 34 and the support base 321 in Figures 16 and 21 is fixed. In Figures 16 and 21, the elastic member 33 is omitted, and the upper base portion 31 is shown to have descended to nearly its maximum extent and approached the lower base portion 32 as indicated by the solid line, but if the compression member 33 is present and the upper load is small, the upper base portion 31 will rise to the position indicated by the imaginary line in the figures.

[0044] When the seat 1 swings forward and backward as shown in Figures 19 and 20, or swings left and right as shown in Figure 23, the upper base portion 31 can move within the range between the flange 342 constituting the first connecting member 34 and the support base 321 (more precisely, the range of distance L between the flange 342 and the lower base plate 322). Since the upper base portion 31 operates while compressing the elastic member 33, when the upper load is released, the upper base portion 31 rises as the elastic member 33 returns to its original position as shown in Figures 16 and 21, and is restricted from further rising when a portion of the upper base portion 31 abuts against the flange 34, as shown by the imaginary lines. The flange 342 prevents the upper base portion 31 from slipping out upward and also restricts the tilt angle when the upper base portion 31 tilts forward, backward, left, right, or diagonally.

[0045] In this embodiment, as shown in Figures 16, 19, and 20, the flange 342 is inclined in the front-to-rear direction so that the front end 342a is higher than the rear end 342b. That is, as shown in Figure 19, when the upper base portion 31 is tilted forward, the rear end 342b of the flange 342 restricts the forward tilt angle of the upper base portion 31, whereas as shown in Figure 20, when the upper base portion 31 is tilted backward, the front end 342a of the flange 342 restricts the backward tilt angle of the upper base portion 31, allowing a larger angle when tilting backward than when tilting forward. As shown in Figures 21 and 23, the left end 342c and the right end 342d of the flange 342 are at the same height, allowing the same angle of tilt in either the left or right direction with respect to the upper base portion 31.

[0046] 11, 20, etc., three pins 341 are fixed to the support base 321, and the upper base plate 312 and the seat holder 311 are inserted into the pins 341. Therefore, the upper base portion 31, which integrates the upper base plate 312 with the seat holder 311, is restricted from rotating relative to the lower base portion 32, which integrates the support base 321 and the lower base portion 322, and the elastic member 33, through which the pins 341 are inserted, is also prevented from twisting clockwise or counterclockwise in plan view. Of course, the number of pins is not limited to three.

[0047] As described above, the second connecting member 35 provides a damping effect to the operation of the moving mechanism 3. Specifically, as shown in FIG. 14 and other figures, the second connecting member 35 mainly comprises seven shafts 351, which are cylindrical members. The holes 311b into which the shafts 351 are inserted and the O-rings 353, which serve as friction materials and are disposed between the shafts 351 and the holes 311b, constitute a damper mechanism DM, which is a braking mechanism. In this embodiment, the holes 311b correspond to recesses in the ribs formed on the bottom wall of the seat 311 constituting the upper base portion 31, and the bottom of the holes 311b is provided with shaft holes 352 through which the shafts 351 pass. Seven sets of shafts 351, holes 311b, and O-rings 353 are provided. Of course, the number of sets is not limited to this.

[0048] Each shaft 351 is bolt-shaped and has a large-diameter base end 351a at its lower end. The upper end is inserted through the second hole 32Q of the support base 321 from the underside of the support base 321, and the base end 351a is accommodated in a recess 355a of a cocoon-shaped backing plate 355 (see Figures 11, 12, etc.) via an elastic plate 354. In this state, the backing plate 355 is placed against the underside of the support base 321 and fixed with a screw (not shown), so that the shaft 351 is attached in a state where it protrudes upward from the support base 321, as shown in Figure 10.

[0049] 14, 19, 20, etc., base end 351a is spherical or flattened spherical, and coupled with the elastic deformation of elastic plate 354 interposed between base end 351a and backing plate 355, shaft 351 is connected to support base 321 of lower base portion 32 so as to be able to swing about base end 351a. In other words, base end 351a of shaft 351, elastic plate 354, and recess 355a of backing plate 355 form non-directional joint UJ (see FIG. 14). Of course, other structures such as a ball joint may be introduced as a non-directional joint that allows shaft 351 to swing freely about the base end.

[0050] This shaft 351 protrudes upward through a second hole 32Q in the lower base portion 32 (i.e., the second hole 32Q in the support base 321 and the second hole 32Q in the lower base plate 322), a second hole 33Q in the elastic member 33 not shown in Fig. 14, and a second hole 31Q in the upper base portion 31 (i.e., the second hole 31Q in the upper base plate 312 and the second hole (shaft hole) 31Q in the seat 311). This shaft 351 constitutes a damper mechanism DM.

[0051] 11, 12, 15, etc., a return spring 36 is interposed around the outer periphery of the shaft 351 as a third connecting member between the upper base portion 31 and the lower base portion 32 to connect them. In this embodiment, the return spring 36 is a coil spring. At three of the seven second holes 31Q to 33Q, the lower base plate 322 of the lower base portion 32 has recessed retainer portions 322R that support the lower end of the return spring 36 in a positioned state, and the second holes 33Q(R), 31Q(R) that open at three locations in the elastic member 33 and the upper base plate 312 have a larger diameter than the return spring 36. At corresponding three of the seven second holes 31Q provided on the underside of the seat 311 that constitutes the upper base portion 31, recessed retainer portions 311R that receive the upper end of the return spring 36 in a positioned state are formed.

[0052] The return springs 36 are arranged at multiple locations (three locations in this embodiment) around the center position (symbol O in FIG. 7) of the movement mechanism 3 over a range of 180° or more (for example, 270°). When the upper base part 31 tilts in any direction, including forward, backward, left, right, or diagonally, the return spring 36 on the tilted side is compressed, and serves to assist the return force that returns the upper base part 31 to the reference position N when there is no upper load. Furthermore, because the back 4 is attached integrally to the seat 1, the return spring 36 also serves to support the load of the movable parts, including these. The return spring 36 may be configured so that the return spring 36 on the side opposite to the tilted side is pulled.

[0053] As described above, the second connecting member 35 is configured by fitting the O-ring 353, which is a friction material, between the pin 351, which is a cylindrical member, and the hole 311b.

[0054] Specifically, as shown in FIG. 14, the shaft hole 352 opens into the bottom wall 311a of the seat 311 that constitutes the upper base portion 31, and the periphery of the bottom wall 311a forms a tapered hole portion 311b that opens upward.

[0055] On the other hand, as shown in Figures 8, 11, 12, 14, etc., the presser 356 is C-shaped in plan view, has an end portion 356a facing the bottom wall 311a, and the periphery of the end portion 356a forms a tapered convex portion 356b that protrudes downward.

[0056] Furthermore, the O-ring 353 has an inner diameter set to fit with the shaft 351 with a predetermined sliding resistance, and this predetermined sliding resistance is designed to obtain a required damping effect when the seat 1 swings. Although NBR rubber is used for the O-ring 353 used in this embodiment, the material is not limited to this, and various materials can be used to achieve the sliding resistance.

[0057] Then, O-ring 353 is fitted from above onto shaft 351 that has passed through shaft hole 352, and presser 356 is pushed from above to fit convex portion 356b into hole 311b, thereby pressing end 356a of O-ring 353 against bottom wall 311a of seat 311, thereby achieving the assembled state shown in Figures 16 and 20. Furthermore, in this state, presser 356 is fastened to the upper surface of seat 311 with bolt V1 shown in Figures 11 and 12, etc., thereby fixing O-ring 353 to seat 311 and therefore to upper base portion 31, as shown in Figure 7. At this time, O-ring 353 shown in Figure 14 is deformed into a flattened ellipse, and comes into contact with the outer periphery of shaft 351 over a surface of a certain area or more, rather than at a point.

[0058] The shaft 351 is a cylindrical member having a base end 351a pivotably attached to the lower base portion 32. The O-ring 353, which is a friction member attached to the seat 311 of the upper base portion 31 and fitted onto the shaft 351, slides along the shaft 351 together with the hole 311b when the upper base portion 31 pivots as shown in FIGS. 19 and 20, and changes its fitting position relative to the shaft 351. The shaft 351 pivots in response to the pivoting of the O-ring 351, and follows the change in the angle of the upper base portion 31 relative to the lower base portion 32. At this time, the relative movement of the hole 311b and the O-ring 353, which is a friction member, relative to the shaft 351, which is a cylindrical member constituting the damper mechanism 35, is a sliding movement along the longitudinal direction of the shaft 351. The shaft 351 may be made of a flexible material that can be bent. In this case, the hole 311b and the O-ring 351 can move along the longitudinal direction of the shaft 351 even if the shaft 351 is not supported so as to be able to swing.

[0059] In other words, the damper mechanism DM is arranged at multiple locations around the center position of the upper base portion 31 over a range of 180° or more (for example, 270°), so that no matter which direction the seat 1 moves through 360°, the shaft 351 and O-ring 353 follow the movement and operate while sliding relative to each other, and perform a damping action due to sliding resistance in both directions of the movement of expanding and contracting the distance between the upper base portion 31 and the lower base portion 32.

[0060] When there is no seating load on this chair configured as described above, the gravity return mechanism GRM will attempt to return the movable parts, including the upper base part 31, seat 1, and back 4, to the position (reference position) where the center of gravity is lowest. At this time, the restoring force of the elastic member 33 and the auxiliary restoring force of the return spring 36 also act, so the chair will come to rest in the most stable position overall. Figures 1 to 3 show the state in which the seat 1 is in reference position N.

[0061] The seat 1 of this chair can swing from the reference position N in 360° directions including front-back, left-right and diagonal directions as the upper base plate 31 rolls relative to the lower base plate 32.

[0062] Looking at the rolling surfaces of such rolling motion, the opposing surfaces of the upper base plate 312 and the lower base plate 322 have first holes 31P and 32P for passing pins 341 constituting the first connecting member as shown in Fig. 24, second holes 31Q and 32Q for passing shafts 341 constituting the second connecting member as shown in Fig. 14, concave retainers 322R (see Figs. 11 and 12) for accommodating return springs as the third connecting member, and return spring insertion holes in the upper base plate 312. In particular, the first hole 31P in the upper base plate 312 shown in Fig. 24 has a large opening to avoid interference with the three pins 341, and the second holes 31Q and 32Q shown in Fig. 14 are numerous because they are provided for each shaft 351. Furthermore, three of these holes have a large diameter to allow return springs 36 to pass through, as shown in Figs. 11 and 12.

[0063] In these holes 31P, 32P, 31Q, 32Q, etc., the continuity of the rolling surfaces 312a, 322a is lost, which means that they are regions of different curvature. For this reason, if the upper base plate 312 constituting the upper base portion 31 rolls directly on the lower base plate 322 constituting the lower base portion 32, the change in curvature is picked up, and rattles easily occur in the upper base portion 31. This rattle then propagates as rattles in the seat 1.

[0064] In contrast, in this embodiment, an elastic member 33 is interposed between the region and the corresponding region of the mating member. This elastic member 33 reduces stability when the opening peripheries of holes 31P, 31Q, etc. in the rolling surface 312 of the upper base portion 31 abut against the opposing rolling surface 322 of the lower base portion 32, and reduces stability when the opening peripheries of holes 32P, 32Q in the rolling surface 322a of the lower base portion 32 abut against the opposing rolling surface 312a of the upper base portion 31. That is, the elastic member 33 facilitates rolling of the rolling surfaces 312a, 322a against each other at locations where the curvature of the rolling surfaces 312a, 322a changes, smoothing the change in curvature. Of course, even in locations where there are no holes, the elastic member 33 also reduces rattling caused by poor or degraded surface accuracy of the rolling surfaces 312a, 322a.

[0065] As shown in Figures 20 and 23, the distance between the upper base portion 31 and the lower base portion 32, which are the opposing rolling surfaces, is smaller on the tilted side of the upper base portion 31 and larger on the opposite side. Because an elastic member 33 is interposed between the upper base portion 31 and the lower base portion 32, the elastic member 33 on the wider side elastically recovers its original shape, while the elastic member 33 on the narrower side is compressed until its thickness becomes extremely small. The elastic member 33 accommodates the pin 341 constituting the main body of the first connecting member 34 and the shaft 351 constituting the second connecting member 35 in the first hole 33P and the second hole 33Q, thereby concealing the pin 341 and the shaft 351 from the side. However, this does not conceal the gap between the upper base portion 31 and the lower base portion 32, and does not function to prevent foreign matter from entering the gap. Although they do not come into direct or indirect contact like the rolling surfaces 312a and 322a, the situation is the same in that it is necessary to shield the space between the pair of oscillating surfaces, including the surfaces facing each other.

[0066] Therefore, in this embodiment, as shown in Figures 20, 25(a), etc., an elastic member 33 is placed in a region extending from the vicinity of the outer peripheral edges 312z, 322z of both opposing oscillating surfaces 312a, 322a to the inside thereof, and an elastic sheet material 60 is provided between the outer peripheral edges 312z, 322z to conceal the gap between the opposing oscillating surfaces 312a, 322a, including the elastic member 33.

[0067] Specifically, grooves 312x, 322x that extend along the outer circumferential edges 312z, 322z and open in opposite directions are provided near the outer circumferential edges 312z, 322z of the opposing oscillating surfaces 312a, 322a, and a cover member 6 having deformable strip materials 61, 62 attached to the edge of an elastic sheet material 60 is provided. Then, as shown in Figures 25(b) and 25(c), the strip materials 61, 62 are sequentially pushed into the grooves 312x, 322x to install them, thereby concealing the gap between the upper base plate 312a and the lower base plate 322a, which form the opposing oscillating surfaces, with the cover member 6. It is arbitrary which groove to install them into first.

[0068] The stretchable sheet material 60 is made of, for example, a knitted polyester fiber material. In this embodiment, the stretchable sheet material 60 is sewn or molded into a cylindrical shape, with thin, annular resin strips 61, 62 integrally attached to the upper and lower ends. The stretchable sheet material 60 is sized and elastic enough to prevent wrinkles when the gap is narrowed to its narrowest and not interfere with the operation of the swing surface when the gap is widened. The grooves 312x, 322x and the strips 61, 62 have a one-to-one relationship, with one strip 61, 62 corresponding to each of the entire grooves 312x, 322x. The strips 61, 62 are long enough to encircle the grooves 312x, 322x. Of course, the material of the stretchable sheet material 60 is not limited to the above. Various materials, such as cloth, upholstery, woven fabric, and knitted fabric, can be used as long as they are stretchable and can cover the interior. The stretchable sheet material 60 is one that can conceal the inside, but it is not prohibited to use one that allows the inside to be seen through a little.

[0069] As the upper base portion 31 moves relative to the lower base portion 32, the cover member 6 follows the movement of the gap between the rolling surfaces 312a, 322a by expanding and contracting as well as deforming, as shown in Figures 19, 20, etc., and keeps the expanding and contracting gap between the upper base portion 31 and the lower base portion 32 always concealed.

[0070] As shown in FIG. 1, the back 4 includes a back support rod 41 and a back body 42 at the upper end thereof. As described above, the back 4 is attached so as to swing together with the seat 1. Specifically, as shown in FIG. 5, a flat insertion port 132b that opens rearward is provided at the rear edge 132a of the seat outer shell 132. Meanwhile, the lower front edge 41a of the back support rod 41 that constitutes the back 4 is shaped to conform to the rear edge 132a of the seat outer shell 132 and is provided with an insertion portion 41b that can be inserted into the insertion port 312b of the seat outer shell 132. Then, with the insertion portion 312b inserted into the insertion port 132b, bolts (not shown) are inserted into the bolt holes 132c and 41c to join the two. In this embodiment, the back body 42 is made of wood.

[0071] As shown in FIG. 1, the armrest 52 is attached to the upper end of the armrest 51, and as described above, it is attached so as not to rock relative to the seat 1 and back 4. Specifically, as shown in FIGS. 3 and 9, an armrest mounting location 321s is provided on the underside of the support base 321, at the rear portion where the cocoon-shaped backing plate 355 is not provided. Meanwhile, the left and right armrests 52 are connected by armrests 51, the base ends of which are attached to a common bracket 53. This bracket 53 is then positioned at the armrest mounting location 321s and fastened from below by a bolt (not shown) passing through a hole 53a in the bracket 53 and a hole 321h in the underside of the support base 321. The armrest 51 extends from this position to the left and right along the underside of the seat 1, rising upward near the rear edge of the seat 1, and then extending forward to provide the armrest 52.

[0072] As described above, the chair of this embodiment is configured with a moving mechanism 3 so that the upper base portion 31 can swing in a 360° direction relative to the lower base portion 32, and in a chair in which a seat 1 is attached to the upper base portion 31, a damper mechanism DM that can operate in response to 360° movement is provided at the position connecting the upper base portion 31 and the lower base portion 32 as a mechanism separate from the moving mechanism 3.

[0073] With this configuration, the upper base portion 31 can follow the free forward / backward, left / right, and diagonal movements of the seated person using the movement mechanism 3, making it easier for the seated person to balance their weight while supporting it, and allowing for stable and continuous posture changes. In particular, since the damper mechanism DM is provided as a mechanism separate from the movement mechanism 3 rather than providing resistance to the movement mechanism 3 itself, the effectiveness of the damper mechanism DM can be adjusted without changing the basic performance of the movement mechanism 3 itself.

[0074] Specifically, the moving mechanism 3 is configured so that the surface 312a, which is one of the opposing surfaces 312a and 322a of the upper base portion 31 and the lower base portion 32, is a curved rolling surface, and the seat 1 provided on the upper base portion 31 oscillates when the upper base portion 31 rolls relative to the lower base 32.

[0075] In this way, the upper base portion 31 rolls on the rolling surfaces 312a and 322a on the lower base portion 32, and the upper base portion 31 can tilt while continuously and smoothly rolling in all directions, front to back, left to right, and diagonally, in accordance with the movement of the seated person. The seated person can stably tilt while balancing the seated weight on the rolling surfaces 312a and 322a, ensuring safety.

[0076] In addition, the moving mechanism 3 of this embodiment is configured to tilt the upper base portion 31 downward in the direction of movement as the seat 1 moves away from the reference position N, regardless of the direction in which the seat 1 moves through 360° from the reference position N.

[0077] Such a configuration is particularly susceptible to rolling when a load is applied in the direction of movement, so the damper mechanism DM of this embodiment is effective.

[0078] In addition, the damper mechanism DM of this embodiment is arranged at multiple locations around a predetermined center O of the seat 1, and can be set to operate in response to at least one or both of the movements of expanding and contracting the distance between the upper base portion 31 and the lower base portion 32.

[0079] Therefore, the damper mechanism DM can be reliably activated regardless of the 360° swing of the seat 1. In particular, design freedom can be achieved by utilizing at least one of the actions of expanding and contracting the distance between the upper base portion 31 and the lower base portion 32, and utilizing both can double the damper effect.

[0080] The damper mechanism DM is located between the upper base portion 31 and the lower base portion 32 and is connected to at least the lower base portion 32 by a non-directional joint UJ.

[0081] In this way, the damper mechanism DM can respond appropriately to the free movement of the seat 1, since it can follow not only the forward / backward and left / right movements of the seat 1 from the reference position N, but also the rotational movement.

[0082] The damper mechanism DM is also composed of a hole 311b provided in one of the upper base portion 31 or the lower base portion 32, a shaft 351 which is a cylindrical member provided in the other and inserted into the hole 311b, and an O-ring 353 which is a friction material arranged between the hole 311b and the shaft 351.

[0083] With this configuration, when the upper base portion 31 moves relative to the lower base portion 32, the O-ring 353 slides against the shaft 351 with a predetermined sliding resistance, making it easy to apply a uniform damper. Also, by devising the shape of the O-ring 353, the sliding resistance can be adjusted.

[0084] Furthermore, the relative movement of the damper mechanism DM in this embodiment is achieved by the sliding movement of the hole 311b and the O-ring 353 along the longitudinal direction of the shaft 351.

[0085] This simplifies the operation of the damper mechanism DM, ensuring stable operation over a long period of time.

[0086] In addition, this embodiment is configured such that an elastically deformable elastic member 33 is provided between the upper base portion 31 and the lower base portion 32, and the upper base portion 31 moves between the upper base portion 31 and the lower base portion 32 while compressing the elastic member 33.

[0087] This provides a softer seating feel and reduces noise compared to when the upper base portion 31 rolls directly on the lower base portion 32. Furthermore, because the elastic member 31 is compressed as the base portion 31 moves, even if the structure allows the upper base portion 31 to roll easily via the rolling surfaces 312a and 322a, the elastic member 33 reduces sudden movement of the upper base portion 31. This not only helps ensure safety, but also prevents the upper base portion from having difficulty returning from its rolling destination due to the damping effect of the damper mechanism DM when returning to the reference position N, using the elastic member 33.

[0088] In this embodiment, a return spring 36 is interposed between the upper base portion 31 and the lower base portion 32 to return them toward a predetermined reference position N.

[0089] By providing such a return spring 36, the return spring 36 prevents the upper base part 31 from moving suddenly when moving away from the reference position N, and when returning to the reference position N, the return spring 36 can prevent a situation in which the damper effect of the damper mechanism DM makes it difficult for the upper base part 31 to return from its rolling destination.

[0090] In addition, in this embodiment, a gravity return mechanism GRM is provided between the upper base portion 31 and the lower base portion 32, which generates a return force to the reference position N by raising the center of gravity of the movable portion including the upper base portion 31 in response to movement of the upper base portion 31 from the reference position N.

[0091] This makes it possible to generate an appropriate return force according to the user's weight, compared to when the return force to the reference position N relies solely on a spring. Furthermore, if the damper mechanism DM alone is not effective enough, the gravity return mechanism GRM can be used, as this mechanism GRM also has a damper function and can appropriately suppress the movement of the seat. Furthermore, when returning to the reference position N, the gravity return mechanism GRM can prevent a situation in which the damper effect of the damper mechanism DM makes it difficult for the upper base part 31 to return from its rolling destination.

[0092] The above describes one embodiment of the present invention, but the specific configuration of each part is not limited to the above-described embodiment, and various modifications are possible within the scope of the present invention. [Explanation of symbols]

[0093] 1…za 3…Movement mechanism 31...Upper base 32...Lower base 33...Elastic member 36...Return spring 311b…hole part 312a, 322a...Facing surfaces (rolling surfaces) 351...Cylindrical member (shaft) 352...Cylindrical member (shaft hole) DM...Damper mechanism GRM...Gravity Return Mechanism N...Reference position O: Predetermined center UJ...Non-directional joint

Claims

1. A chair having a movement mechanism configured so that an upper base portion can swing in 360° directions relative to a lower base portion, and a seat attached to the upper base portion, a damper mechanism that can operate in accordance with 360° movement is provided at a position connecting the upper base part and the lower base part as a mechanism separate from the movement mechanism; the damper mechanism is configured to include a hole provided in one of the upper base portion or the lower base portion, a cylindrical member provided in the other of the upper base portion and inserted into the hole, and a friction material disposed between the hole portion and the cylindrical member, The hole has a tapered shape that opens upward, and the cylindrical member can pass through the hole. A chair characterized by:

2. The chair of claim 1, wherein the moving mechanism includes a rolling surface curved on at least one of the opposing surfaces of the upper base portion and the lower base portion, and the seat provided on the upper base portion oscillates as the upper base portion rolls relative to the lower base.

3. 3. The chair of claim 1, wherein the movement mechanism is configured to tilt the upper base portion downward in the direction of movement as the seat moves away from the reference position, regardless of whether the seat moves in any direction through 360 degrees from the reference position.

4. A chair as described in any one of claims 1 to 3, wherein the damper mechanism is arranged at multiple locations around a predetermined center of the seat and operates in response to at least one or both of the movements of expanding and contracting the distance between the upper base portion and the lower base portion.

5. 5. The chair according to claim 1, wherein the damper mechanism is located between the upper base portion and the lower base portion and is connected to at least one of the base portions by a non-directional joint.

6. The chair according to any one of claims 1 to 5, wherein the relative movement of the damper mechanism is a sliding movement of the hole and the friction material along the longitudinal direction of the cylindrical member.

7. A chair according to any one of claims 1 to 6, wherein an elastically deformable elastic member is provided between the upper base portion and the lower base portion, and the upper base portion moves between the upper base portion and the lower base portion while compressing the elastic member.

8. 8. The chair according to claim 1, wherein a return spring is interposed between the upper base portion and the lower base portion to return the chair to a predetermined reference position.

9. A chair as described in any one of claims 1 to 8, wherein a gravity return mechanism is provided between the upper base portion and the lower base portion, which generates a return force to the reference position by raising the center of gravity of the movable portion including the upper base portion in response to movement of the upper base portion from the reference position.

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