This application claims priority of Japanese Patent Applications No. 2021-162892 filed on Oct. 1, 2021. The contents of the applications are incorporated herein by reference in their entirety.
The present invention relates to a chair that is suitably utilized in an office or the like and in which a seat is movable in front-rear, left-right, and diagonal directions.
Examples of chairs having a seat that is movable in front-rear, left-right, and diagonal directions include the chairs described in Japanese Unexamined Patent Application Publication No. 2009-82521 and Japanese Unexamined Patent Application Publication No. 2009-297319 (hereinafter referred to as Patent Documents 1 and 2).
Patent Document 1 describes a configuration in which a plurality of fluid bags are connected by a flow path and a seat is tilted when air moves.
Patent Document 2 describes a configuration in which a plurality of independent air cushions are covered with a cover member and fitted into a recess of a seat to provide a cushioning property to a person sitting in the chair.
In the configurations of Patent Documents 1 and 2, the seat can move freely by the cushioning effect. However; the degree of freedom of deformation of the seat is too high for a seated person to hold his or her posture on the seat, and therefore, the seated person needs to follow a movement of the seat rather than the seat following a movement of the seated person. As a result, the conventional seats are not designed suitably for supporting a movement of the seated person continuously changing his or her posture while the seated person balances his or her load.
To solve such a problem, a configuration is conceivable in which an upper base unit that receives a load of the seated person move in a direction of 360 degrees along a predetermined trajectory via a movement mechanism with respect to a lower base unit that supports the upper base unit, and a seat is attached to the upper base unit.
However, when only such a movement mechanism is employed, the movement can be regular to a certain degree, but the degree of freedom of the seat is still too high. Thus, when a user changes his or her posture, the user has to support his or her own weight during moving, so that a burden to the user may be high.
The present invention has been accomplished in view of such a problem, and an object thereof is to realize an unprecedented chair which has a simple structure and in which a seat can follow a free movement of a seated person in front-rear, left-right, and diagonal directions, a burden from an operation by which the seated person balances his or her load can also be reduced, and a movement by which the seated person changes his or her posture stably and continuously can be suitably supported.
The present invention adopts the following means to achieve such an object.
That is, a chair of the present invention includes a movement mechanism that causes an upper base unit to swing in a direction of 360 degrees with respect to a lower base unit, and a seat attached to the upper base unit. The chair further includes a damper mechanism as a mechanism separate from the movement mechanism, at a position connecting the upper base unit and the lower base unit, and the damper mechanism operates by following a movement in a direction of 360 degrees.
According to such a configuration, the upper base unit can follow a free movement of a seated person in front-rear, left-right, and diagonal directions by the movement mechanism, and the seated person can easily find a weight balance while supporting his or her own weight, and can change his or her posture stably and continuously. In particular, instead of imparting resistance to the movement mechanism, the damper mechanism is provided as a mechanism separate from the movement mechanism, and thus, it is possible to adjust a working condition of the damper mechanism, without changing the basic performance of the movement mechanism.
In an example of a specific embodiment of the movement mechanism, the movement mechanism includes a rolling surface that is curved and provided in at least one of surfaces of the upper base unit and the lower base unit that face each other, and when the upper base unit rolls with respect to the lower base unit, the seat provided in the upper base unit swings.
Such a damper mechanism is especially suitable when applied to a chair that causes the upper base unit to tilt downward in a movement direction of the seat, as the seat moves away from a reference position, regardless of which direction of 360 degrees the seat moves in from the reference position.
To increase the degree of freedom in design and achieve an appropriate damper effect, it is desirable that the damper mechanism is arranged at a plurality of locations around a predetermined center of the seat, and operates in at least one direction or both directions of an operation of expanding or contracting a distance between the upper base unit and the lower base unit.
To obtain a damper mechanism that appropriately responds to the free movement of the seat, it is desirable that the damper mechanism is provided between the upper base unit and the lower base unit and connected by a non-directional joint to at least one of the upper base unit and the lower base unit.
To achieve a uniform and easily adjustable damper effect, it is desirable that the damper mechanism includes a hole unit provided in one of the upper base unit and the lower base unit, a columnar member provided in the other one of the upper base unit and the lower base unit and inserted into the hole unit, and a friction material arranged between the hole unit and the columnar member.
To ensure a stable operation, it is desirable that a relative movement of the damper mechanism is a sliding motion of the hole unit and the friction material along a longitudinal direction of the columnar member.
An example of an embodiment preferred in relation to the damper mechanism includes a configuration in which an elastic member being elastically deformable is provided between the upper base unit and the lower base unit, and the upper base unit moves while compressing the elastic member between the upper base unit and the lower base unit.
Another embodiment preferred in relation to the damper mechanism includes a configuration in which a return spring that returns the seat to a predetermined reference position is interposed between the upper base unit and the lower base unit.
In an example of an embodiment preferred in relation to the damper mechanism, other than the one described above, a gravity return mechanism that generates a return force toward a reference position by raising a position of a center of gravity of a movable portion including the upper base unit, in accordance with a movement of the upper base unit from the reference position, is provided between the upper base unit and the lower base unit.
The present invention has the configuration described above, and thus, it is possible to provide a novel, useful chair designed to follow a free movement of a seated person in front-rear, left-right, and diagonal directions, and to appropriately support a movement of the seated person continuously changing his or her posture while balancing his or her load.
An embodiment of the present invention will be described below with reference to the drawings.
In the seat 1, a circumference of a seat main body 11 is covered with upholstery 12, and the seat 1 is attached to the movement mechanism 3 via a seat shell 13. The seat shell 13 includes an inner seat shell 131 attached to a bottom surface of the seat main body 11 and an outer seat shell 132 that backs up the inner seat shell 131 and secures the connection to the movement mechanism 3.
The leg 2 includes casters 22 at a lower end of a leg vane 21, and a leg support post 23 erected from a center portion of the leg vane 21, and the seat 1 is rotatably attached to an upper end side of the leg support post 23. The leg support post 23 can be extended and contracted by a gas spring mechanism GS illustrated in
As illustrated in
The movement mechanism 3 supports the upper base unit 31 movably with respect to the lower base unit 32, in the front-rear direction as illustrated in
As illustrated in
As illustrated in
The curved surface has a substantially partial spherical shape or a substantially arc-shaped cross section, in other words, the curved surface has a bowl-shape or a convex R-shape, and the upper base unit 31 may move in directions of 360 degrees including the front-rear, left-right, and diagonal directions, while rolling on the lower base unit 32. The curved surface may be implemented in various modes, such as a surface that is curved at a constant curvature, even at a position separated from a reference position N which is a contact position between the two base units 31 and 32 when no load is applied, a surface having a curvature that smoothly changes as the distance from the reference position N increases, a surface having different curvature in the front-rear and left-right directions, and a surface having different curvature between the front and the rear.
As illustrated in
As illustrated in
In the present embodiment, the high-elastic urethane foam is adopted, because high-elastic urethane foam has low temperature dependence and excellent durability. Needlessly to say, low-elastic urethane foam may be used for the elastic member, or a thin member such as an elastic sheet may be used.
When the upper base unit 31 receives a load and moves in any direction of 360 degrees including the front-rear, left-right, and diagonal directions with respect to the lower base unit 32, as illustrated in
Generally, it is conceivable to use, as the movement mechanism, a guide mechanism composed of a cam and a follower between an upper base unit and a lower base unit, and a link mechanism connecting the upper base, unit. and the lower base unit. Compared to such a structure, the movement mechanism 3 of the present embodiment utilizes the rolling surfaces 312a and 322a to realize an operation of the seat 1 in which a tilting movement component is larger than a horizontal movement component. The chair of the present embodiment that performs such an operation is particularly easy to use in a situation where a person frequently sits down and stands up from a seat.
The curvatures of the rolling surfaces 312a and 322a are set so that a gravity center position G of the seat 1 is lifted to G′ by the movement, as illustrated by a solid line and an imaginary line in
As illustrated in
In addition, in the upper base unit 31, the lower base unit 32, and the elastic member 33, first holes 31P to 33P for inserting a pin 341 constituting the first connection member 34 are opened along a first line L1, and second holes 31Q to 33Q for inserting a shaft 351 constituting the second connection member 35 are opened along a second line L2. The holes 31P, 32P, 33P, 31Q, 32Q, and 33Q prevent the pin 341 and the shaft 351 from interfering with the rolling surfaces 312a and 322a and the elastic member 33, and thus, are also referred to as “relief holes” herein.
The first connection member 34 is mainly composed of three of the pins 341, and the pins 341 are formed as an integral member with a flange unit 342. The pins 341 are inserted through the first hole 31P of the upper base unit 31 (that is, the first hole 31P of the seat receiver 311 and the first hole 31P of the upper base plate 312), the first hole 33P of the elastic member 33, and the first hole 32P of the lower base unit 32 (that is, the first hole 32P of the lower base plate 322), respectively, and the pins 341 are fastened from below by bolts (not illustrated) at positions where the pins 341 abut against the support base unit 321 constituting the lower base unit 32.
With such a structure, for example, a relative position (distance L) between the flange unit 342 of the first connection member 34 and the support. base unit 321 in
When the seat 1 swings in the front-rear direction as illustrated in
In the present embodiment, as illustrated in
As illustrated in
As described above, the second connection member 35 imparts a damper effect to the operation of the movement mechanism 3. Specifically, as illustrated in
Each of the shafts 351 is a bolt-shaped shaft having a large-diameter proximal end unit 351a at a lower end. In a state where the upper end side of the shafts 351 is inserted through the second hole 32Q of the support base unit 321 from the bottom surface side of the support base unit 321, the proximal end unit 351a is accommodated in a recessed unit 355a of a cocoon-shaped (see
As illustrated in
The shafts 351 protrude upward via the second hole 32Q of the lower base unit 32 (that is, the second hole 32Q of the support base unit 321 and the second hole 32Q of the lower base plate 322), the second hole 33Q of the elastic member 33 (not illustrated in
On the other hand, as illustrated in
The return spring 36 is arranged at a plurality of locations (three locations in the present embodiment) over a range of 180 degrees or more (for example, 270 degrees) around a center position (reference numeral O in
As described above, the second connection member 35 has a configuration in which the O-rings 353 made of a friction material are fitted between the shafts 351, which are columnar members, and the hole units 311b.
Specifically as illustrated in
On the other hand, as illustrated in
An inner diameter of the O-rings 353 is chosen so that the O-rings 353 fit with the shafts 351 with a predetermined sliding resistance, and the predetermined sliding resistance is chosen so that a required damper effect can be obtained when the seat 1 swings. In the present embodiment, NBR rubber is used for the O-rings 353. However, the material is not limited thereto, and various materials may be adopted as the material for realizing the sliding resistance.
The shafts 351 are passed through the shaft holes 352 and fitted to the O-rings 353 from above, and the pressing tool 356 is pushed from above to fit the projecting unit 356b into the hole unit 311b. Thus, the O-rings 353 are pressed against the bottom wall 311a of the seat receiver 311 by the end unit 356a to realize the assembled state illustrated in
If the upper base unit 31 swings, as illustrated in
That is, the damper mechanism DM is arranged at a plurality of locations around a center position of the upper base unit 31 over a range of 180 degrees or more (for example, 270 degrees). Therefore, if the seat 1 moves in any direction of 360 degrees, the shafts 351 and the O-rings 353 operate while following the movement of the seat 1 and sliding relative to each other, and exert a damper action by a sliding resistance in both directions of an operation in which a distance between the upper base unit 31 and the lower base unit 32 is expanded or contracted.
In a chair having such a configuration, in a state where no seating load is applied, the gravity return mechanism GRM mentioned above attempts to return the chair to a position (reference position) where the center of gravity of the movable portion including the upper base unit 31, the seat 1, and the back 4 is lowest. At that time, a restoring force of the elastic member 33 and an auxiliary restoring force of the return spring 36 act together, and thus, the chair stops at the overall most stable position.
The seat 1 of the chair can swing from the reference position N in any direction of 360 degrees including the front-rear, left-right, and diagonal directions, when the upper base plate 312 performs a rolling operation with respect to the lower base plate 322.
In the rolling surfaces performing such a rolling operation, the upper base plate 312 and the lower base plate 322, which are surfaces facing each other, include the first holes 31P and 32P for passing the pins 341 constituting the first connection member as illustrated in
In the holes 31P, 32P, 31Q, 32Q, and the like, regions having different so-called curvatures are formed and the continuity of the rolling surfaces 312a and 322a is impaired. Therefore, if the upper base plate 312 constituting the upper base unit 31 rolls directly on the lower base plate 322 constituting the lower base unit 32, the upper base unit 31 is likely to rattle due to the change in the curvature. The rattling propagates as a rattling of the seat 1.
On the other hand, in the present embodiment, the elastic member 33 is interposed between the above-described region in one of the upper base unit 31 and the lower base unit 32 and a corresponding region in the other one of the upper base unit 31 and the lower base unit 32. The elastic member 33 lowers the stability when opening peripheral edges of the holes 31P, 31Q, and the like existing in the rolling surface 312a of the upper base unit 31 abut against the rolling surface 322a of the lower base unit 32 facing the rolling surface 312a, and lowers the stability when opening peripheral edges of the holes 32P and 32Q existing in the rolling surface 322a of the lower base unit 32 abut against the rolling surface 312a of the upper base unit 31 facing the rolling surface 322a. That is, the elastic member 33 facilitates rolling between the rolling surfaces 312a and 322a at a place where the curvature of the rolling surfaces 312a and 322a changes and smooths the change of the curvature. Needlessly to say, even in a place where no hole is formed, and also a place where the surface of the rolling surfaces 312a and 322a is irregular or deteriorated, the elastic member has an effect of reducing the rattling caused by the irregular or deteriorated surface.
As illustrated in
Therefore, in the present embodiment, as illustrated in
Specifically, grooves 312x and 322x extending along the outer peripheral edges 312z and 322z and opening in opposite directions are provided in the vicinity of the outer peripheral edges 312z and 322z of the swinging surfaces 312a and 322a facing each other, and in the cover member 6, deformable strips 61 and 62 are attached to edge portions of the Stretchable sheet material 60. As illustrated in
For example, the stretchable sheet material 60 is formed by using a material obtained by knitting polyester fibers. In the present embodiment, the stretchable sheet material 60 is sewn or formed into a cylindrical shape, and the strips 61 and 62 made of resin and having an annular thin plate shape are integrally provided at the upper end and the lower end of the stretchable sheet material 60. The size and elasticity of the stretchable sheet material 60 are chosen so that no wrinkles are generated when the gap is most narrow and so that the stretchable sheet material 60 does not hinder the operation of the swinging surface when the gap is widened. The relationship between the grooves 312x and 322x and the strips 61 and 62 is one-to-one, and each of the strips 61 and 62 corresponds to the entire area of one of the grooves 312x and 322x, and the strips 61 and 62 are provided having a length that surrounds the grooves 312x and 322x. Needlessly to say, the material of the stretchable sheet material 60 is not limited to the above-described materials, and various materials such as cloth, upholstery, woven fabric, and knitted items can be used, as long as the material can be stretched and contracted and covers the inside. The stretchable sheet material 60 that can hide the inside is used, but the stretchable sheet material 60 may be a material through which the inside is slightly visible.
As illustrated in
As illustrated in
As illustrated in
As described above, the chair of the present embodiment includes the movement mechanism 3 that causes the upper base unit 31 to swing in a direction of 360 degrees with respect to the lower base unit 32, and the seat 1 attached to the upper base unit 31. Further, the chair of the present embodiment is provided with the damper mechanism DM that may operate by following a movement in a direction of 360 degrees, as a mechanism separate from the movement mechanism 3, at a position connecting the upper base unit 31 and the lower base unit 32.
According to such a configuration, the upper base unit 31 can follow a free movement of the seated person in the front-rear, left-right, and diagonal directions by the movement mechanism 3, and the seated person can easily find a weight balance while supporting his or her own weight, and can change his or her posture stably and continuously. In particular, instead of imparting resistance to the movement mechanism 3, the damper mechanism DM is provided as a mechanism separate from the movement mechanism 3, and thus, it is possible to adjust a working condition of the damper mechanism DM, without changing the basic performance of the movement mechanism 3.
Specifically in the movement mechanism 3, the surface 312a, which is one of the surfaces 312a and 322a of the upper base unit 31 and the lower base unit 32 facing each other, forms a curved rolling surface, and the upper base unit 31 rolls with respect to the lower base unit 32, so that the seat 1 provided in the upper base unit 31 swings.
Thus, the upper base unit 31 rolls on the lower base unit 32 using the rolling surfaces 312a and 322a, and thus, the upper base unit 31 can tilt white rolling continuously and smoothly in the front-rear, left-right, and diagonal directions according to the movement of the seated person. The seated person can perform a stable tilting motion while balancing a load of the seated person on the rolling surfaces 312a and 322a, and thus, the safety is also ensured.
The movement mechanism 3 of the present embodiment causes the upper base unit 31 to tilt downward in the movement direction of the seat 1, as the seat 1 moves away from the reference position N, regardless of which direction of 360 degrees the seat 1 moves in from the reference position N.
In such a configuration, a rolling movement is easily generated particularly by a load applied in the movement direction, and thus, the damper mechanism DM of the present embodiment is an effective damper mechanism.
The damper mechanism DM of the present embodiment can be arranged at a plurality of locations around a predetermined center O of the seat 1, and may operate in at least one direction or both directions of an operation in which the distance between the upper base unit 31 and the lower base unit 32 expands or contracts.
Therefore, the damper mechanism DM can be surely operated, regardless of which direction of 360 degrees the seat 1 swings in. In particular, a degree of freedom in design can be obtained by utilizing at least one of the operations of expanding or contracting the distance between the upper base unit 31 and the lower base unit 32, and if both operations are utilized, the damper effect can be doubled.
The damper mechanism DM is provided between the upper base unit 31 and the lower base unit 32, and connected by a non-directional joint UJ at least to the lower base unit 32.
Therefore, the damper mechanism DM can follow the front-rear and left-right movements of the seat 1 from the reference position N, but also a movement in a rotation direction, so that the damper mechanism DM can appropriately adapt to a free movement of the seat 1.
The damper mechanism DM includes the hole units 311b provided in any one of the upper base unit 31 and the lower base unit 32, the shafts 351 which are columnar members provided in the other one of the upper base unit 31 and the lower base unit 32 and inserted into the hole units 311b, and the O-rings 353 which are friction materials arranged between the hole units 311b and the shafts 351.
According to such a configuration, if the upper base unit 31 moves relative to the lower base unit 32, the O-rings 353 slide with respect to the shafts 351 at a predetermined sliding resistance, and thus, it is easy to apply a uniform damper effect. The sliding resistance can be adjusted by adapting the shape of the O-rings 353.
The relative movement of the damper mechanism DM of the present embodiment is a sliding motion of the hole units 311b and the O-rings 353 along the longitudinal direction of the shafts 351.
Thus, the operation of the damper mechanism DM is simplified, so that stable operation can be ensured for a long period of time.
In the present embodiment, the elastic member 33 that can be elastically deformed is provided between the upper base unit 31 and the lower base unit 32, and the upper base unit 31 moves while compressing the elastic member 33 between the upper base unit 31 and the lower base unit 32.
With such a configuration, as compared to a case where the upper base unit 31 rolls directly on the lower base unit 32, it is possible to obtain a softer sitting feel and it is also possible to prevent generation of undesirable noise. The elastic member 33 is compressed with the movement of the upper base unit 31, and thus, even in a structure in which the upper base unit 31 easily rolls via the rolling surfaces 312a and 322a, the elastic member 33 attenuates an abrupt operation of the upper base unit 31. Therefore, the elastic member 33 is useful for ensuring safety, and the elastic member 33 can prevent a situation where the upper base unit 31, when returning to the reference position N, does not easily return from a position after the rolling movement due to the damper effect of the damper mechanism DM.
In the present embodiment, the return spring 36 for returning the upper base unit 31 toward the predetermined reference position N is interposed between the upper base unit 31 and the lower base unit 32.
If the return spring 36 is provided, the return spring 36 prevents the upper base unit 31 from moving abruptly when moving away from the reference position N, and the return spring 30 can prevent a situation where the upper base unit 31, when returning to the reference position N, does not easily return from a position after the rolling movement due to the damper effect of the damper mechanism DM.
In the present embodiment, the gravity return mechanism GRM that generates a return force toward the reference position N by raising the position of the center of gravity of the movable portion including the upper base unit 31, according to the movement of the upper base unit 31 from the reference position N, is provided between the upper base unit 31 and the lower base unit 32.
Thus, as compared with a case where the return force toward the reference position N depends only on a spring, it is possible to generate an appropriate return force according to the body weight. Moreover, adopting the gravity return mechanism GRM when the effect achieved by the damper mechanism DM alone is insufficient, makes it possible to appropriately suppress the movement of the seat, because the mechanism GRM also has a damper function. The gravity return mechanism GRM can prevent a situation where the upper base unit 31, when returning to the reference position N, does not easily return from a position after the rolling movement due to the damper effect of the damper mechanism DM.
The embodiment of the present invention has been described, and a specific configuration of each unit is not limited to that in the embodiment described above and various modifications are possible without departing from the gist of the present invention.
1 . . . Seat
3 . . . Movement mechanism
31 . . . Upper base unit
32 Lower base unit
33 . . . Elastic member
36 . . . Return spring
311
b . . . Hole unit
312
a,
322
a . . . Facing surfaces (rolling surfaces)
351 . . . Columnar member (shaft)
352 . . . Cylindrical member (shaft hole)
DM . . . Damper mechanism
GRM . . . Gravity return mechanism
N . . . Reference position
O . . . Predetermined center
UJ . . . Non-directional joint
Number | Date | Country | Kind |
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2021-162892 | Oct 2021 | JP | national |