JP2015027588A - Chair with backrest - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair capable of reducing a load on a human body by accurately supporting a lumbar part in both cases where a person sits on the front edge of the chair and sits back in the chair.SOLUTION: A chair includes: a seat 4, a backrest 6, and a back frame 5. The backrest 6 is attached to the back frame 5 so as to allow a lumbar part support part 6a to be moved forward/backward with the upper part as a center. The lower end of the backrest 6 is attached to the back frame 5 via links 26, 29, 28, and the second link 26 is connected to the fourth link 29 by a gas cylinder 30. When the lumbar part support part 6a moves backward against the gas cylinder 30, a state where a person is supported by the lumbar part support part 6a is kept even when his/her seated position is different in a front and rear direction.

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 back does not change only when a person is seated. 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). 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, 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 according to the invention of claim 1 includes a seat, a backrest whose lower part is a waist support part, and a back frame to which the backrest is attached, and at least the waist support part of the backrest is the back frame. The body of the person who is seated is supported at least by the waist support part from behind by supporting the back part of the at least waist support part from the back by spring means. It is possible to maintain the state.

  A chair according to a second aspect of the present invention is the chair according to the first aspect, wherein the back frame can be tilted backward against the locking spring means.

  A chair according to a third aspect of the present invention is the chair according to the first or second aspect, wherein the backrest is rotatably attached to the back frame so that the waist support portion moves back and forth largely around the upper end portion thereof. .

  The chair of the present invention can support the waist of the seated person from behind with a back even if a person sits shallowly on the seat. In other words, the backrest can exhibit a lumbar support function, which can significantly reduce the burden on the user's body. In addition, since the backrest is supported from behind by spring means, the waist support part can move back and forth following the movement of the user even if the user moves the body back and forth, so it has excellent fit. preferable.

  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 has a kind of barrier-free property because it can accurately support the waist even when seated shallowly. It can be said.

  The configuration of claim 2 is suitable because it can also exhibit a locking function.

(A) is a side view of the first embodiment, and (B) is a perspective view of an inner shell of a backrest. (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 front view of the main member which fractured | ruptured a part. FIG. 4 is a sectional view taken along line IV-IV 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.

  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 the chair, FIG. 1B is a perspective view of the inner shell of the backrest, FIG. 2A is a side view of the main member separated, and FIG. 1B is an attached state of the backrest. 3 is a partially broken perspective view, 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. 5 is a side view showing movement.

  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 an inner shell 7 schematically shown in FIG. 1B, and a cushion material 8 is stretched on the front surface of the 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 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 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 '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 that supports 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 an inner shell 4a made of resin or the like. Then, a U-shaped bracket 14 having the same lateral width as that of the intermediate member 3 and opened downward 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 connected to each other in two pairs of front and rear first links. 15 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 protrusion integrally formed with the inner shell 4a of the seat 4. 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). . In other words, a crosspiece 19 having a laterally long and inwardly U-shaped cross section is fixed to the upper end 5 b ′ of the left and right back struts 5 b by welding or the like. The protruding piece 20 is integrally formed with the protruding piece 20, and the protruding piece 20 is fastened to the crosspiece member 19 with screws (bolts) 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-shaped piece 22 surrounded by the upwardly opened slit in the inner shell 7. For this reason, when the tongue-like piece 22 is deformed so as to bend, the backrest 6 tilts (rotates) around the root of the tongue-like piece 22, and the backrest 6 as a whole is on the front side of the back column part 5b. Is allowed to move to. The protruding piece 20 may be formed of a member different from the inner shell 7.

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

  A belt-like push plate 24 that is long in the left-right direction is fixed to the back surface of the waist support portion 6a in the backrest 6 by screwing or the like.

  Next, the interlocking means will be described. In this embodiment, the lower support 6a of the backrest 6 is projected forward by using the downward movement of the seat 4, and the interlocking means is provided on the inner surface of the first link 15 and the left and right back frames 5 described above. Front and rear long second links 26 connected 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 second links 26 A fourth link 29 that is rotatably connected to 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 inner shell 7 of the backrest 6.

  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 is formed at the front end of the second link 28 so as to open forward in a side view. The left and right longitudinal holes fixed to the bracket 14 on the lower surface of the seat 4 via the auxiliary member 14a are formed in the long slot 33. The operating shaft 34 is fitted.

(2). Explanation of Movement / Advantages of Embodiment In the above configuration, when a person sits down on the seat 4, as shown in FIG. 5, the seat 4 slides backward while being lowered as a whole 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, so that the waist 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 waist support portion 6a of the backrest 6 does not move forward due to the contraction of the gas cylinder 30, so that it is not hindered from sitting deeply. Moreover, since the waist 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 user's physique is different. For this reason, it is comfortable to sit. Further, even when the waist support portion 6a is deformed, it is not impaired to sit deeply.

  When the gas cylinder 30 of this embodiment is provided, the waist 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 waist 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. It is slightly larger than the tilt angle (because the amount of movement increases as the distance from the center of rotation of the back frame 5 increases). For this reason, a deep comfort posture can be taken.

  Further, since the backrest 6 tilts backward in a natural posture when sitting, the backrest 6 does not receive a feeling of being pushed up by the back and waist of the person, and a comfortable rocking state without a sense of incongruity can be obtained. Furthermore, when the person is seated, the backrest 6 tilts backward, so that the user can lean on the backrest 6 with the upper body tilted backward in a state where the back frame 5 is not tilted backward. Before the back frame 5 starts to tilt backward, the state appears as if entering the preparatory stage of locking, and as a result, the transition to the locking state is performed very smoothly.

Further, when the seat 4 is lowered by locking, the front portion of the second link 26 is pushed downward by the operating shaft 34, so that the backrest 6 is lowered more than when it is simply attached to the back frame. 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 differences from the first embodiment are that the first link 15 is provided with a stopper pin 36, the fourth link 29 and the lower end of the waist 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 connecting shaft 32, the third link 28 and the fifth link 37 are connected to each other). 38, a plurality of mounting holes 39 are formed.) The operating shaft 34 is attached to a bearing portion 40 formed on the 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. In addition, since the fifth link 37 is present, the lumbar portion of the seated person can be accurately supported because the shape curved in the forward convex shape in the side view and the waist support portion 6a is maintained.

  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 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 as viewed from the left side by the pressing action of the guide member 44, whereby the backrest 6 is tilted backward and is 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 for sliding the seat 4, an outer cylinder is fixed to the intermediate member 3 with two guide shafts 48 that are inclined forward and left in a side view and are slidably fitted to the guide shaft 48. The bracket 50 is fixed to 49 and the seat 4 is fixed to the bracket 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 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 bracket 50 is fitted into 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 bracket 50 is formed in an inverted letter shape when viewed from the right side (it is a letter shape when viewed from the left side), and as a means for sliding the seat 4, the inclined portion 59a of the bracket 50 is slid obliquely rearward. The rail 60 to be used and the eleventh link 61 connected to the upper portion of the bracket 50 and the seat receiving base 2 are used in combination. A long hole 62 is formed in the inclined portion 59 a of the bracket 50, and a guide pin 63 protruding from the seat receiving base 2 is fitted in the long 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 waist 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 of the thirteenth link 65 is connected to a bearing bracket 67 provided on the back surface of the waist support portion 6a by a pin 66 '. The twelfth link 64 is pushed by a protrusion 59 b formed on the bracket 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 inner shell in the backrest 6, but a spring means for return 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. 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.

DESCRIPTION OF SYMBOLS 1 Leg support | pillar 2 Seat receiving base 3 Intermediate member 4 Seat 5 Back frame 6 Backrest 6a Waist support part 7 Inner shell of backrest 15 1st link 26 2nd link 28 3rd link 29 4th link 30 Gas cylinder 34 Actuating shaft

Claims (1)

A seat, a backrest whose lower portion is a waist support portion, and a back frame to which the backrest is attached; at least a waist support portion of the backrest is movable back and forth with respect to the back frame; By supporting at least the waist support part with respect to the back frame from behind by a spring means, it is possible to maintain the seated person's body supported at least from the back by the waist support part. Yes,
Chair with backrest.

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