JP2007152145A - Chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To supply a chair that exhibits a lumber support function even though a user sits in slightly. <P>SOLUTION: The chair is provided with a leg strut 1, a seat receiving base 2, a seat 4, and a backrest 6. The backrest 6 is mounted on a back frame 5. A middle member 3 is relatively and rotatably mounted on the seat receiving base 2 and the back frame 5 seen from the side and the seat 4 is mounted on the middle member 3 via a parallel link 15. When the user sits on the seat 4, the seat 4 approaches the backrest 6 while lowering backward by the rotation of the parallel link 15. So even though the user sits in slightly, the lumber support function is exhibited by the backrest 6. As the middle member 3 inclines backward while moving backward, the seat 4 also inclines backward in locking while moving backward. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 to push the person into a forward tilted posture, 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). It is often necessary to sit down shallowly in business, so it is highly necessary to consider such usage conditions.)

  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, in the configuration of Patent Document 2, there is a problem that when a person sits shallowly, the seat is tilted forward, so that it is difficult for the person to take an upright posture by stretching the upper body.

  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 according to the invention of claim 1 has a backrest having a seat on which a person sits, and a lumbar support portion on which the waist of a person seated on the seat can come into contact. A sliding means for retreating toward the back without any movement, and a spring means for returning the seat to its original position when a person stands from the seat.

  The chair according to a second aspect of the present invention is the chair according to the first aspect, wherein the seat is attached to a link that tilts backward in a side view or a seat receiving member that slides obliquely downward in a side view. When a person sits down, he descends while descending.

  According to a third aspect of the present invention, in addition to the structure of the first or second aspect, the leg support, the seat support base fixed to the upper end of the leg support, the backrest is attached and the seat support base is attached. A back frame coupled so as to be able to tilt backward, and a locking spring that elastically supports the rear tilt of the back frame, and the slide means is supported by a seat receiving base and a back frame. The back frame does not tilt backward only by seating the seat, and when the seated person leans against the backrest, the back frame and the seat tilt backward against the locking spring.

  In the chair of the present invention, when the person is seated, the seat retreats so that the backrest can exhibit a lumbar support function. Therefore, even in a shallow sitting state, the burden on the user's body can be reduced.

  When the lumbar support portion of the backrest is advanced by sitting as in the embodiment, it is possible to more reliably support the human waist with the lumbar support portion by sitting. Furthermore, if it comprises as Claim 3, it can exhibit a locking function and is suitable.

  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 backrest inner shell (hereinafter referred to as “back inner shell”), and FIG. 2A is a separated side view of main members. (B) is a partially broken separated perspective view showing the state of attachment of the backrest, FIG. 3 is a schematic separated front view of the main member with a partially broken view, FIG. 4 is a sectional view taken along the line VV in FIG. 1, and FIG. It is a side view.

  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 having a front portion attached to the seat receiving base 2, a seat 4 attached to the intermediate member 3, and a seat receiving member. Two back frames 5 are connected to the base 2 so as to be tiltable rearwardly, and a backrest 6 supported by the back frame 5 is provided.

  The backrest 6 includes a back inner shell 7 schematically shown in FIG. 1B, and a cushion material 8 is stretched on the front surface of the back inner shell 7 as clearly shown in FIG. 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 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 12 ′ is attached to 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 substantially vertically, 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 halfway portion 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 'that 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 locking spring for supporting the backward movement of the first shaft 11 is disposed inside the seat receiving base 2, and the backrest 6 is locked against this spring.

  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, an open U-shaped bracket 14 is fixed to the lower surface of the seat 4 in the same lateral width as that of the intermediate member 3 in the downward direction. Are 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 It is connected to the intermediate member 3 by a dedicated shaft 16. A shaft connecting the first link 15 to the bracket 14 is indicated by reference numeral 17. In the non-sitting state (neutral state), the first link 15 is slightly tilted backward as viewed from the side. This is for tilting backward by sitting. 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. The first link 15 may be connected to a downward projection integrally formed with the seat inner shell 4a. Needless to say, the means for sliding the seat 4 backward by the seating (that is, the sliding means) is not limited to the parallel link mechanism. In the present embodiment, the intermediate member 3 and the group of the first links 15 constitute a seat receiving member.

  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. Therefore, 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-shaped cross-section is fixed to the upper end portion 5b 'of the left and right back struts 5b by welding or the like, while the back inner shell 7 is attached to the upper surface of the crosspiece 19 The overlapping protruding pieces 20 are integrally formed, and the protruding pieces 20 are fastened to the crosspiece member 19 with screws (bolts) 21.

  In this case, as a feature of the present embodiment, a vertically elongated tongue-like piece 22 is formed in the back inner shell 7 by forming a slit 22a having an upward opening shape, and a protruding piece is formed at the lower end of the tongue lock piece 22. 20 is formed. 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 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 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 of the lumbar support portion 6a in the backrest 6, a belt-like push plate 24 that is long in the left-right 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 protrudes forward by using the backward sliding movement of the seat 4, and the interlocking means includes the first link 15 and the left and right back frames 5 described above. Front and rear long second links 26 connected to the inner surface by the first connecting shaft 25, left and right third links 28 connected to the push plate 24 of the backrest 6 via left and right long second connecting shafts 27, 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 24a (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.

  The gas cylinder 30 is rotatably connected to the second link 26 and the fourth link 29 by a pin 31. 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. .

  A long slot 33 opened forward in a side view is formed at the front end portion of the second link 26, 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 lumbar support portion 6a of the backrest 6 is pushed back by the contraction of the gas cylinder 30, so that it is not obstructed to sit deeply. 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.

  When the gas cylinder 30 of this embodiment is provided, the lumbar support portion 6a can move back and forth following the movement of the user even when 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-like piece 22, so that when the person is seated, the backrest 6 is in a tilted posture as a whole. The rearward tilt angle is an angle obtained by adding the angle at which the backrest 6 tilts backward by sitting and the rearward 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. It is slightly larger than the tilt angle (because the amount of movement increases with increasing distance from the center of rotation of the back frame 5). 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. Further, when the user sits down, the backrest 6 tilts backward, so that the user can lean on the backrest 6 with the upper body tilted backward when the backframe 5 is not tilted backward. As a result, the transition to the locking state is performed very smoothly.

  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.

  When 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. Are connected by the fifth link 37, and the attachment positions of the third link 28 and the fifth link 37 with respect to the fourth link 29 are adjustable (the connection shaft 32 is connected to the third link 28 and the fifth link 37). 38, a plurality of mounting holes 39 are formed along the longitudinal direction. The operating shaft 34 is attached to a bearing portion 40 formed in the seat inner shell 4a.

  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. In addition, since the fifth link 37 is present, the lumbar support portion 6a and the shape that is curved in a forward convex shape in a side view are maintained, 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 preference. 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 parallel link type first link 15, a seesaw-type sixth link 42 in which the upper and lower halfway parts are connected to the left and right side surfaces of the intermediate member 3 by a 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 by the pressing action of the guide member 44, whereby the lumbar support portion 6 a of the backrest 6 is moved. It 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 the slide means for sliding the seat 4 toward the backrest 6 by sitting, two left and right guide shafts 48 that are inclined forward in side view are fixed to the intermediate member 3, and the guide shaft 48 is fixed to the guide shaft 48. The seat receiving member 50 is fixed to the outer cylinder 49 fitted slidably, and the seat 4 is fixed to the seat receiving member 50. The outer cylinder 49 incorporates 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 5a 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). Fifth to sixth embodiments (FIGS. 10 to 11)
FIG. 10 shows a fifth embodiment. In this embodiment, the seat receiving member 59 is formed in an inverted letter shape when viewed from the right side (a letter shape when viewed from the left side), and the inclined portion 59a of the seat receiving member 59 serves as a sliding means for sliding the seat 4. And the eleventh link 61 connected to the upper part of the seat receiving member 59 and the seat receiving base 2 are used in combination. An elongated hole 62 is formed in the inclined portion 59 a of the seat receiving member 59, and a guide pin 63 protruding from the seat receiving base 2 is fitted in the elongated hole 62.

  As interlocking means for converting the slide of the seat 4 into the forward movement of the backrest 6, a bell crank type twelfth link 64 that rotates by the slide of the seat 4, and a twelfth link 64 of the back frame 5. The bell crank type 13th link 65 which advances the lumbar support part 6a of the backrest 6 by rotation is connected. The twelfth link 64 and the thirteenth link 65 are engaged by a pin 66 so as to rotate together.

  The tip end of the thirteenth link 65 is connected to a bearing bracket 67 provided on the back surface of the lumbar support portion 6a by a pin 67 '. The twelfth link 64 is pushed by a protrusion 59 b formed on the seat receiving member 59.

  The sixth embodiment shown in FIG. 11 is a modification of the fifth embodiment, and the twelfth link 64 is configured in a seesaw manner extending linearly. The back frame 5 is provided with a guide body 65 a for ensuring that the thirteenth link 65 tilts forward by the rotation of the twelfth link 64. In these embodiments (and other embodiments), the seat 4 and the link can be returned to the neutral state by the elastic restoring force of the back inner shell 7, but return spring means may be provided. In the fifth embodiment and the sixth embodiment, the interlocking means can be arranged below the seat 4 and on the front side of the back frame 5, so that there is an advantage that the appearance is refreshed as a whole.

(7) 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.

(A) is a side view of the first embodiment, and (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. It is a figure which shows 5th Embodiment. It is a figure which shows 6th Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Leg support | pillar 2 Seat receiving base 3 Intermediate member 4 Seat 5 Back frame 6 Backrest 6a Lumber support part 7 Back inner shell which comprises backrest 15 1st link 26 2nd link 28 3rd link 29 4th link 30 Gas cylinder 34 operation | movement axis

Claims (3)

A seat on which a person sits down, a backrest having a lumbar support part on which the waist of a person sitting on the seat can hit, and a sliding means for retreating the seat toward the backrest with little or no change in side view when seated Spring means to return the seat to its original position when a person stands from the seat,
Equipped with a chair. The seat is attached to a link that tilts backward in a side view or a seat receiving member that slides obliquely downward in a side view, so that the seat moves backward while descending when a person sits down.
The chair according to claim 1. Furthermore, a leg post, a seat base fixed to the upper end of the leg post, a back frame to which the backrest is attached and connected to the seat base so as to be able to tilt backward, and a rear tilt of the back frame. A sliding spring that is elastically supported, and the sliding means is supported by a seat receiving base and a back frame, and the back frame does not tilt backward when a person is seated, and the seated person has a backrest. The back frame and seat are designed to tilt backward against the locking spring.
The chair according to claim 1 or 2.

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