JP4857146B2 - Chair with backrest - Google Patents

Description

  The present invention relates to a chair with a backrest.

  There are various types of chairs, and various improvements are made according to each type. As an example, for example, Patent Document 1 discloses a chair in which the seat tilts forward when a seated person leans against the backrest, while Patent Document 2 discloses that the seat is positioned at a substantially middle portion before and after the seated person. There is described a chair that tilts in side view around the center and that the backrest tilts in conjunction with the rear tilting of the seat. Both patent documents employ a kind of link mechanism as means for interlocking the backrest with the seat.

  In the case of Patent Document 1, the posture of the seat and the backrest is not changed only by the person sitting, and when the seated person leans on the backrest and a large moment is applied to the backrest, the rear part of the seat is pushed upward by the lever principle. It is intended to tilt the seat forward, and its purpose is to ensure a comfortable state by making it easier to stretch the human body in the locked state.

On the other hand, in Patent Document 2, for example, when a person sits on the front part of the seat, the backrest greatly tilts forward and pushes the person forward, and the user feels uncomfortable and shifts the sitting position backward. It will be. That is, in Patent Document 2, a so-called “chung (or choi)” that a user sits on the front part of a seat gives a discomfort and a correct sitting posture.
Japanese Examined Patent Publication No. 44-20784 Japanese Examined Patent Publication No.46-27517

When a person uses a chair, he does not necessarily sit deeply, but often sits shallowly. Since the use of chairs varies from person to person, the design philosophy of the chair also requires a user-friendly idea to minimize the burden on the user even if the sitting position is different (such as in offices). because there often be sitting shallow in business, the need to consider such a use state is high.).

  However, the thing of patent document 1 is only assumed that it is in a rocking state, and no consideration is given to what is called a shallow sitting. On the other hand, the thing of patent document 2 is trying to make the user put on the heel which sits down deeply, and it is hard to say that this also considers a user enough.

  Furthermore, in order to reduce the burden on the body of a person who has been seated, it is important to support the person's waist and make it easier to take a state where the back is stretched. A chair with a lumbar support that supports it in a concentrated manner is prevalent, but since the one in Patent Document 2 tilts the entire backrest forward, the user of the chair is pushed by the backrest at the top of the backrest. As a result, the spine is not stretched, and therefore the lumbar support function cannot be secured in Patent Document 2.

  Furthermore, the configuration of Patent Document 2 has a problem that when a person sits shallowly, the seat is inclined forward, and it is difficult for the person to take an upright posture with the upper body extended.

  This invention is made | formed in view of such the present condition, and makes it a subject to provide a more user-friendly chair.

The chair targeted by the present invention is provided with a seat that descends at least when a person sits down and returns to the original when the person leaves, and a backrest having a lumbar support part that can be touched by the waist of the seated person. When the seat is lowered after being seated, at least the lumbar support portion of the backrest can be advanced by the interlocking means.

Then, in the invention of claim 1, wherein the interlocking means includes a gas cylinder or an elastic body as a member for advancing at least the lumbar support portion of the backrest, the seat occupant before the lumbar support unit as possible forward If the waist is hitting the lumbar support portion, the seat while allowing it as possible lowered, forward of the lumber support portion by said gas cylinder retracts or elastic body is deformed is adapted to be blocked .

The chair according to a second aspect of the present invention is the chair according to the first aspect, wherein the seat is supported by the seat receiving member so as to move down while retracting with little or no change in the side view. Is mainly flexible so that the lumbar support part can move forward, and the interlocking means includes an elastic body.
As described in claim 3, the present invention includes a configuration in which a seating load is converted into hydraulic pressure or pneumatic pressure, and the backrest is advanced by a cylinder using the hydraulic pressure or pneumatic pressure.

  In the chair of the present invention, when a person sits down, at least the lumbar support part of the backrest protrudes forward, so that even if a person sits shallowly on the seat, the seated person's waist can be supported from behind by the backrest. That is, the backrest can exert a lumbar support function, and therefore, the burden on the user's body can be remarkably reduced even in a shallow sitting state such as a so-called chest.

  For example, elderly people, women, and other small people may be forced to sit shallowly on the chair, but the chair of the present invention also has a kind of barrier-free property because it can support the waist accurately even when seated shallowly. It can be said.

  According to the second aspect of the present invention, since the seat can slide without changing the posture in the side view and the lumbar support portion of the backrest can accurately support the seated person's waist, the user can extend the back muscles. Can take a different posture. This is another feature of the present invention. Further, according to the second aspect of the present invention, the seat lumbar support part moves forward in addition to the seating backward movement, so that the person's waist is supported more reliably.

In claim 1, when a person sits deeply on the chair, the lumbar support portion of the backrest is pushed back by contraction of the gas cylinder or deformation of the elastic body. Further, when the user moves his / her body back and forth due to expansion / contraction of the gas cylinder or deformation of the elastic body, the lumbar support part can move back and forth following the movement of the user. For this reason, it is excellent also in fit property.

  Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a rotary chair for office use or the like.

(1). Structure of First Embodiment FIGS. 1 to 5 show the first embodiment. 1A is a side view of a chair, FIG. 1B is a perspective view of a back inner shell of a backrest, FIG. 2A is a separated side view of main members, and FIG. 1B is an attached state of the backrest. 3 is a partially broken perspective view showing FIG. 3, FIG. 3 is a schematic separated front view of a main member partially broken, FIG. 4 is a sectional view taken along line IV-IV in FIG. 1, and FIG.

  The chair includes a leg support 1 made of a gas cylinder, a seat receiving base 2 fixed to the upper end thereof, an intermediate member 3 attached to the seat receiving base 2, a seat 4 attached to the intermediate member 3, and a seat receiving base 2. Two left and right back frames 5 connected so as to be tiltable rearwardly and a backrest 6 supported by the back frame 5 are provided.

  The backrest 6 includes a back inner shell 7 schematically shown in FIG. 1 (B), and a cushion material 8 is stretched on the front surface of the back inner shell 7 as clearly shown in FIG. 2 (B). Although not shown in the drawings, the leg support 1 is attached to a leg base having a plurality of branch branches extending radially, and each branch branch is provided with a caster.

  The seat base 2 is formed in a box shape opened upward, and the intermediate member 3 is connected to the front portion thereof by a first shaft 11 that is long in the left-right direction. The intermediate member 3 is formed in an open U shape in a front view (see FIG. 3), and the first shaft 11 passes through the side plate 3 a and the seat receiving base 2. The insertion hole of the first shaft 11 in the seat receiving base 2 is a long hole 12 extending rearwardly in a side view, so that the first shaft 11 can slide along the long hole 12. A resin bush 13 is mounted in the long hole 12.

The back frame 5 is composed of an arm portion 5a that is inclined rearward when viewed from the side and a back column 5b that extends in a substantially vertical shape, and has a generally square shape when viewed from the side. The distal end portion of the arm portion 5 a and the front and rear intermediate portions of the seat receiving base 2 are connected by the second shaft 13. Further, the rear part of the intermediate member 3 and the front / rear halfway part of the arm part 5a are connected by a third shaft 13 'which is long in the left-right direction. Therefore, the intermediate member 3 and the back frame 5 move backward while tilting in conjunction with each other. Although not shown, a spring for supporting the backward movement of the first shaft 11 is arranged inside the seat receiving base 2, and the backrest 6 is locked (and the rear tilt and slide of the seat 4). Done against.

  The seat 4 has a structure in which a cushion 4b is stretched on the upper surface of a seat inner shell 4a made of resin or the like. Then, a U-shaped bracket (seat receiving member) 14 that is opened downward with substantially the same width as the intermediate member 3 is fixed to the lower surface of the seat 4, and the left and right side plates of the bracket 14 and the intermediate member 3 are paired in the front and rear. Each of the first links 15 is connected by a parallel link mechanism.

Each first link 15 is located outside the bracket 14 and the intermediate member 3, the front first link 15 is connected to the intermediate member 3 by the first shaft 11, and the rear first link 15 is dedicated. The shaft 16 is connected to the intermediate member 3. A shaft connecting the front and rear first links 15 to the bracket 14 is denoted by reference numeral 17. In a non-sitting state (neutral state), the first link 15 is inclined slightly rearward from the vertical line in a side view. This is because Ru is tilted backward of the first link 15 by the seating. Although not shown, a stopper is provided to prevent the first link 15 from tilting forward.

By connecting the seat 4 and the intermediate member 3 with the parallel link mechanism, the seat 4 can be lowered and lowered without changing the posture in side view. In other words, the seat 4 does not tilt forward or backward, and can move backward while descending while maintaining a substantially horizontal posture. Note that without using the bracket 14, the first link 15 may be coupled to a downward projection which is integrally formed on the seat inner shell 4a. Needless to say, the means for sliding the seat 4 is not limited to the parallel link mechanism.

  The upper part 5 b ′ of the back column part 5 b in the back frame 5 is separated from the lower part thereof and is connected via a coil spring 18. For this reason, the upper end portion 5 b ′ of the back column portion 5 b can tilt backward against the elasticity of the coil spring 18.

  The backrest 6 is attached to the upper end portion 5b 'of the back column portion 5b in the back frame 5 at a portion of the back surface that is somewhat below the upper end, and its specific structure is shown in FIG. 2 (B). . That is, a crosspiece 19 having a laterally long and inwardly U-shaped cross section is fixed to the upper end portion 5b 'of the left and right back struts 5b by welding or the like, and the protruding piece overlapping the top surface of the crosspiece 19 on the back inner shell 7 20 is integrally formed, and the protruding piece 20 is fastened to the crosspiece member 19 with a screw (bolt) 21.

  In this case, as a feature of the present embodiment, the protruding piece 20 is formed at the lower end of the vertically long tongue-like piece 22 surrounded by the slit opened upward in the back inner shell 7. For this reason, when the tongue-like piece 22 is deformed so as to bend, the backrest 6 tilts around the root of the tongue-like piece 22 and the backrest 6 moves to the front side of the back column part 5b as a whole. And are allowed. The protruding piece 20 may be formed of a member different from the back inner shell 7.

  The backrest 6 includes a lumbar support portion (waist support portion) 6a that hits a portion centered on the waist of a seated person. The lumbar support portion 6a is curved in a forwardly convex shape in a side view, and the lumbar support portion 6a moves back and forth when the backrest 6 tilts in a side view with the tongue-like piece 22 as the center. As shown in FIG. 1 (B), the back inner shell 7 of the backrest 6 is provided with such a flexibility that the shape in side view and the shape in plan view can be changed at least at the location of the lumbar support portion 6a. Giving flexibility to the back inner shell 7 can be achieved, for example, by forming a group of slits.

  On the back surface of the lumbar support portion 6a in the backrest 6, a belt-like push plate 24 having a left and right longitudinal direction is fixed by screwing or the like.

Next, the interlocking means will be described. In this embodiment, the lumbar support portion 6a of the backrest 6 is projected forward by using the downward movement of the seat 4 and the backward sliding movement, and the interlocking means includes the first link 15 described above and the left and right back frames. A second link 26 that is longitudinally connected to the inner surface of 5 by a first connection shaft 25, a third link 28 that is connected to the push plate 24 of the backrest 6 via a second connection shaft 27 that is left and right, and A fourth link 29 that is rotatably connected to the two links 26 and the third link 28 and a pair of left and right gas cylinders 30 that maintain a relative angle between the second link 26 and the fourth link 29 are provided. . The front end of the third link 28 is connected to a bearing piece 24 a (see FIG. 4) formed on the push plate 24, but may be connected to a rearward protruding piece formed on the back inner shell 7 of the backrest 6.

Gas cylinder 30 is rotatably connected by a pin 31 to the second link 26 and the fourth link 29. Note that only one gas cylinder 30 may be disposed at the left and right intermediate portions, or three gas cylinders 30 may be disposed at three locations with the left and right intermediate portions of the second link 26.

  The lower end of the fourth link 29 is connected to the second connecting shaft 27, and the rear end of the third link 28 and the upper end of the fourth link 29 are connected by the fourth connecting shaft 32. The second link 26 is formed in a bowl shape with an upward opening, and the lower end portion of the fourth link 29 and the lower end portion of the gas cylinder 30 are located inside the second link 26. Further, since the interval between the left and right third links 28 is wider than the interval between the left and right second links 26, a large interval is provided between the third link 28 and the fourth link 29 as shown in FIG. .

  The front end of the second link 26 is formed with a long slot 33 that opens forward in a side view, and the left and right longitudinal slots fixed to the bracket 14 on the lower surface of the seat 4 via the auxiliary member 14a. The operating shaft 34 is fitted.

(2). Explanation of Movement and Advantages of Embodiment In the above configuration, when a person sits on the seat 4, as shown in FIG. 5, the seat 4 slides backward while being lowered by the action of the parallel link mechanism. Then, the second link 26 is rotated to the forward inclined posture by the pressing action of the operating shaft 34, and then the relative angle between the second link 26 and the fourth link 29 is held constant by the gas cylinder 30. The third link 28 is pushed forward, whereby the lumbar support portion 6a of the backrest 6 moves forward greatly. For this reason, even if a person sits shallowly on a chair, the person's waist can be accurately supported and the lumbar support function can be exhibited.

When a person sits deeply on the chair, the seat 4 is lowered and slid backward, and the lumbar support portion 6a of the backrest 6 does not move forward due to the contraction of the gas cylinder 30. There is nothing. Moreover, since the lumbar support part 6a of the backrest 6 has flexibility so that the side view shape and the planar shape can be changed, the backrest 6 fits the human body even if the physique of the user is different. For this reason, it is comfortable to sit on. Further, even when the lumbar support portion 6a is deformed, it is not impaired to sit down deeply.

  Furthermore, since the gas cylinder 30 is provided, the lumbar support portion 6a can move back and forth following the movement of the user even if the user moves his / her body back and forth. In addition, by locking the gas cylinder 30, the initial advance position of the lumbar support portion 6a can be adjusted. An elastic body such as a coil spring can be provided instead of the gas cylinder 30.

  When the seated person leans on the backrest 6, the backrest 6 tilts backward as a whole, and the seat 4 also tilts backward while moving backward. In this case, the portion close to the upper end of the backrest 6 is attached to the back column 5b via the tongue-shaped piece 22, so that when seated, the backrest 6 assumes a rearward tilting posture as a whole. The tilt angle is an angle obtained by adding the angle at which the backrest 6 tilts backward by sitting and the rear tilt angle of the back frame 5. Therefore, comfort in the locked state can be improved.

Further, the back frame 5 tilts backward in the locked state as shown by a one-dot chain line in FIG. 5, and the backrest 6 is lowered as a whole by the backward tilting of the back frame 5. tilt angle increases slightly than (because the amount of movement farther from the center of rotation of the back frame 5 is increased.). For this reason, a deep comfort posture can be taken.

Further, since the backrest 6 tilts backward in a natural posture when seated, the backrest 6 does not receive a feeling of pushing up on the back and waist of the person at the time of rocking, and a comfortable rocking state without a sense of incongruity can be obtained. Furthermore, inclined posture becomes larger after the backrest 6 when seated (by the lumbar support section 6a advances, side view orientation of the front surface of the backrest 6 is a posture that is tilted back than the non-seating state) by the user Can hang on the backrest 6 with the upper body tilted backwards when the back frame 5 is not tilted back, so that the back frame 5 can enter the locking preparation stage before starting the back tilt As a result, the transition to the locking state is extremely smoothly performed.

  Further, when the seat 4 is moved downward by locking, the front portion of the second link 26 is pushed downward by the operating shaft 34, so that the backrest 6 moves more downward as compared with the case where the backrest 6 is simply attached to the back frame 5. Therefore, it is possible to prevent a so-called shirt-rolling phenomenon caused by an increase in the relative distance between the seat 4 and the backrest 6.

If the upper portion of the back column portion 5b is bent against the spring 18 as in the present embodiment, the cushioning property in the locked state is enhanced, so that the comfort can be further improved.

(3). Second embodiment (FIGS. 6 to 7)
6 and 7 show the second embodiment. 6 is a side view in a non-sitting state, and FIG. 7 is a partial side view in a sitting state.

This embodiment is a modification of the first embodiment. The difference from the first embodiment is that a stopper pin 36 is provided on the first link 15, the fourth link 29 and the lower end of the lumbar support portion 6a. the points connected by the fifth link 37, the third link 28 and in that it can be adjusted is the mounting position of the fifth link 37 (third link 28 and the fifth link 37 with respect to the fourth link 29, connecting shaft 32 38, a plurality of mounting holes 39 are formed. The operating shaft 34 is attached to a bearing portion 40 formed on the seat inner shell 4 a of the seat 4.

  In the second embodiment, the slide of the seat 4 is restricted by the stopper pin 36 of the first link 15 coming into contact with the upper surface of the intermediate member 3. Further, since the fifth link 37 is present, the lumbar support portion 6a is maintained in a shape that is curved forward and convex in a side view, so that the lumbar portion of the seated person can be accurately supported.

  Furthermore, since the attachment positions of the third link 28 and the fifth link 37 with respect to the fourth link 29 can be adjusted, the initial shape and the front-rear position in the side view of the backrest 6 can be changed. The position and profile of the backrest 6 can be set according to the above. In addition, you may enable it to adjust a side posture and back-and-forth position of the backrest 6 steplessly.

(4) Third embodiment (FIG. 8)
FIG. 8 shows a third embodiment. In this embodiment, as interlocking means, in addition to the first link 15 of the parallel link method, a seesaw-type sixth link 42 in which the upper and lower middle portions are connected to the left and right side surfaces of the intermediate member 3 by the sixth connection shaft 41, Connected to the seventh link 43 that connects the sixth link 42 and the side surface of the backrest 6, guide members 44 provided on the left and right side surfaces of the seat 4, the lower end of the sixth link 42, and the upper and lower middle portions of the seventh link 43 The gas cylinder 30 is provided.

  The guide member 44 has a long hole 45 extending substantially rearwardly. A slide pin (or roller) 46 provided at the upper end of the sixth link 42 is fitted into the long hole 45. Further, the lower end of the seventh link 43, the sixth link 42 and the sixth connecting shaft 41 are connected to the intermediate member 3. Each link is arranged in a pair on the left and right.

  In this embodiment, when a person is seated, the sixth link 42 and the seventh link 43 are rotated counterclockwise as viewed from the left side by the pressing action of the guide member 44, whereby the backrest 6 is tilted rearward and the lumbar The support portion 6a moves forward greatly.

(5). Fourth embodiment (FIG. 9)
FIG. 9 shows a fourth embodiment. (A) is a right side view, (B) is a partial plan sectional view. In this embodiment, as a means (sliding means) for sliding the seat 4, two guide shafts 48 that are inclined forward and left in a side view are fixed to the intermediate member 3, and are slidably fitted to the guide shaft 48. The seat receiving member 50 is fixed to the inserted outer cylinder 49, and the seat 4 is fixed to the seat receiving member 50. The outer cylinder 49 includes a spring 51 that returns the seat 4 to the neutral state.

  Then, a reinforcing bar 52 having a square cross section or the like is fixed to the front surfaces of the left and right back struts 5b by welding or the like, and the front and rear intermediate portions of the eighth link 53 are connected to the left and right end surfaces of the reinforcing bar 52 by an eighth connecting shaft 54. The operating shaft 34 fixed to the seat receiving member 50 is fitted in a longitudinally long slot 55 provided in the front portion of the eighth link 53. Further, the eighth link 53 and the push plate 24 of the backrest 6 are connected by the ninth link 56 and the tenth link 57. The eighth link 53 corresponds to the second link 26 of the first embodiment, the ninth link 56 corresponds to the third link 28 of the first embodiment, and the tenth link 57 corresponds to the fourth link 29 of the first embodiment. It corresponds to.

(6). Other Variations The present invention can be embodied in various ways other than the above embodiment. For example, the application target is not limited to a rotating chair for office use, but can be applied to various chairs such as a sofa for a hospital, a fixed chair for a theater or a stadium, or a vehicle chair.

  Further, the interlocking means for moving the backrest forward by sitting is not limited to the embodiment, and various configurations can be adopted. For example, as a configuration in which the seat only moves downward by sitting, the backrest may be advanced by this downward movement. It is also possible to convert the load caused by the seating into hydraulic pressure or pneumatic pressure, and advance the backrest by the cylinder using this hydraulic pressure or pneumatic pressure.

It is a figure which shows 1st Embodiment, (A) is a side view, (B) is a perspective view of a back inner shell. (A) is a separated side view of the main member, and (B) is a partially broken separated perspective view showing an attached state of the backrest. It is a general | schematic isolation | separation front view of the main member which fractured | ruptured a part. FIG. 5 is a cross-sectional view taken along the line V-V in FIG. 1. It is a side view which shows a movement. It is a side view in the non-sitting state of 2nd Embodiment. It is a side view in the seating state of a 2nd embodiment. It is a figure which shows 3rd Embodiment. It is a figure which shows 4th Embodiment.

DESCRIPTION OF SYMBOLS 1 Leg support 2 Seat receiving base 3 Intermediate member 4 Seat 5 Back frame 6 Backrest 6a Lumber support part 7 Back inner shell 14 Bracket (seat receiving member)
DESCRIPTION OF SYMBOLS 15 1st link which comprises interlocking means 26 2nd link which comprises interlocking means 28 3rd link which comprises interlocking means 29 4th link which comprises interlocking means 30 Gas cylinder which comprises interlocking means 34 Actuation axis

Claims (3)

A seat that descends at least when a person sits down and returns to the original when the person leaves, and a backrest that has a lumbar support part that can be touched by the seated person's waist, and when the person sits and the seat descends, At least the lumbar support part of the backrest can be advanced by interlocking means,
The structure
When the interlocking means includes a gas cylinder or an elastic body as a member for advancing at least the lumbar support portion of the backrest, the lumbar region of the seated person before the lumbar support unit as possible forward is hitting the lumbar support section, while permitting said seat as possible lowered, forward of the lumber support portion by said gas cylinder retracts or elastic body is deformed is adapted to be blocked,
Chair with backrest. While the seat is supported by the seat receiving member so as to descend while moving backward with little or no change in the side view, the backrest is mainly flexible so that the lumbar support portion can move forward. And the interlocking means includes an elastic body.
A chair with a backrest according to claim 1. It has a seat on which a person sits, a backrest having a lumbar support that can be touched by the seated person's waist, and a cylinder that operates with hydraulic pressure or pneumatic pressure converted by a load caused by the seating of the person. When the cylinder is operated, at least the lumbar support portion of the backrest can be advanced by the interlocking means.
The structure
The interlocking means includes a gas cylinder or an elastic body as a member for advancing at least the lumbar support part of the backrest, and when the lumbar support part is in contact with the lumbar support part before the lumbar support part has fully advanced, The lumbar support part is prevented from advancing by allowing the cylinder to be fully operated, or by contracting the gas cylinder or deforming an elastic body.
Chair with backrest.

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