JP5875164B2 - 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 whose seat tilts forward when a seated person leans against the backrest, while Patent Document 2 discloses that a seat is positioned at a substantially intermediate portion before and after the seat. 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 leans forward and pushes the person forward, and the user feels uncomfortable and sits back. Will shift. 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's often necessary to sit shallowly in business, so there is a high need to consider such usage.)

  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. While chairs with lumbar support to centrally support is of widespread, those disclosed in Patent Document 2, because in which tilted forward the entire backrest, seated occupant is pushed to the top of the backrest in the backrest Te can not be extended back muscles waiting to become stoop state, therefore, the Patent Document 2 lumbar support function can not be ensured.

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
“A seat arranged above the seat base, a backrest that serves as a waist support portion that supports the back of the person seated at the bottom, and a back frame to which the backrest is attached,
The back frame is connected to the seat receiving base so as to be rearwardly tiltable and extends rearward from the lower side of the seat. When the back frame is tilted rearward, the seat is reared to a smaller degree than the back frame. While leaning
The upper end of the back frame is connected to a backrest ,
The upper part of the back frame can be tilted backward against elasticity with a body pressure caused by a seated person leaning against the backrest centering on a portion located above the lumbar support portion of the backrest . for this reason, the back frame, that obtained tilted backward largely upper than the lower part in the locking state, "
That's it.

The chair according to the invention of claim 2 is the chair according to claim 1,
The top and back of "the back frame are consolidated in the right and left two positions,
The upper part of the back frame can be deformed independently at two places on the left and right sides, and the backrest can be twisted and deformed in plan view by the body pressure of the seated person.
That's it.

Chair of the present invention may be supported from behind by the back waist of the sitting person. That backrest Ru can exert a lumbar support function. And since the upper part of a back frame inclines back against elasticity at the time of locking, the cushioning property in a locked state becomes high and can improve comfort.

(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.

Next, an embodiment of the present invention will be described with reference to the drawings. This embodiment is applied to a rotating chair office 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.

  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, the leg support 1 is attached to a leg base having a plurality of radially extending branches, and casters are provided on each branch.

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. The long hole 12 is fitted with a resin bush 12 '.

The back frame 5 is composed of two left and right arm portions 5a inclined in a rear view, and back strut portions 5b extending substantially vertically from the left and right arm portions 5a. It is in the form of Then, the distal end portion of the left and right 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 portion of the intermediate member 3 and the front and rear middle portions of the left and right arm portions 5a are connected by a third shaft 13 'that is long in the left and right directions. Therefore, the intermediate member 3 and the back frame 5 are moved backward while being interlocked (the degree of backward inclination of the intermediate member 3 is smaller than the degree of backward inclination of the back frame 5) . 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.

As shown in FIG. 3, 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, the lower surface of the seat 4, the intermediate member 3 and the U-shaped bracket 14 which is open downward substantially in the same horizontal width is fixed, the side plates and the intermediate member 3 of the bracket 14, first of two pairs about one They are connected by a parallel link mechanism comprising links 15.

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. Axis linking 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 inclined 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 move backward while descending without changing the posture in side view. In other words, the seat 4 can be retracted while descending while maintaining a substantially horizontal posture without tilting forward or backward. 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 end portion 5 b ′ of the left and right back column portions 5 b in the back frame 5 is separated from the lower portion thereof and is connected via a coil spring 18. Therefore, the upper end 5b of the right and left rear struts 5b 'may be tilted backward respectively against the resilience 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 part of the back surface that is somewhat lower than the upper end, and its specific structure is shown in FIG. 2 (B). Yes. That is, a crosspiece 19 having a laterally long and inward 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 inner shell 7 constituting the backrest 6 A protruding piece 20 is integrally formed on the upper surface of 19, 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-like 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 can support a portion centered on the waist of a seated person from behind . 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 has been connected to the bearing piece 24a formed on the push plate 24 (see FIG. 4) may be connected to the rearward projecting 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. The gas cylinder 30 may be disposed only one of the left and right intermediate portions may be, for example, by three arranged in three positions of the right and left ends and an intermediate portion of the second link 26.

The lower end of the fourth link 29 is connected to the first connecting shaft 25, the rear end of the third link 28 and the upper end of the fourth link 29 are connected by a fourth connecting shaft 32. The second link 26 is formed in trough-shaped upwardly opening, the lower end of the lower portion and the gas cylinder 30 of the fourth link 29 is located inside of 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. .

As shown in FIGS. 1 (A) and 2 (A), the front end portion of the second link 28 is formed with a long slot 33 that opens forward in a side view. left and right longitudinal operating shaft 34 which is fixed via an auxiliary member 14a to the lower surface of the bracket 14 is fitted.

(2). Explanation of Movement / 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 as a whole by the action of the parallel link mechanism. To do. 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 body of the seated person even if the user's physique is different. . For this reason , it is comfortable to sit on. 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. Instead of the gas cylinder 30, an elastic body such as a coil spring can be provided.

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 portion 5b via the tongue-like piece 22, so that when the person is seated , the backrest 6 assumes a backward tilting posture as a whole, The rearward tilt angle of the upper body 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, as shown by a one-dot chain line in FIG. 5, the back frame 5 tilts backward in the rocking state, and the backrest 6 is lowered as a whole by the rearward tilting of the back frame 5. It is slightly larger than the rearward tilt angle (because the amount of movement increases as the distance from the rotation center 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. Further, when the person sits down, 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. For this reason, 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 by the locking is lowered dynamic, by the front of the second link 26 is pushed downward by the actuating shaft 34, the backrest 6 is more lowered dynamic simply compared with the case of 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.

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 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. 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. Further, 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. Further, by the fifth link 37 is present, since the shape of the waist support portion 6a is curved in the forward convex shape in side view is maintained, it is possible to accurately support the lumbar part of the seated person.

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. Note that the side surface posture and longitudinal position of the backrest 6, may be adjustable 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 open elongated hole 45 extending in a substantially rear傾状, in the elongated hole 45, it has put order fit the slide pin (or a roller) 46 provided at the upper end of the sixth link 42. Further, the lower end of the seventh link 43 and the upper and lower halfway portion of the sixth link 42 are connected to the intermediate member 3 by the sixth connecting shaft 41. 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). Other variations present invention can be in addition to various concrete than the above embodiment. For example, application-to-elephant is not limited to the rotating chair of the office, such as, for example, fixed chairs such as for sofas and theatrical or stadiums such as for the hospital, or can be applied to a variety of chairs, such as a chair for vehicle .

1 leg support 2 seat receiving base 3 intermediate member 4 seat 5 back frame
5a Back frame arm
5b Back strut part of back frame
5b 'Upper end of the back strut 6 Backrest 6a Waist support 7 Backrest inner shell
13 Second axis (back frame tilting spindle
15 First link
18 Coil spring
19 Crosspiece
22 Tongue piece 26 Second link 28 Third link 29 Fourth link 30 Gas cylinder 34 Operating shaft

Claims (2)

A seat disposed above the seat base, a backrest that serves as a waist support portion that supports the back of the lower back seated person, and a back frame to which the backrest is attached;
The back frame is connected to the seat receiving base so as to be rearwardly tiltable and extends rearward from the lower side of the seat. When the back frame is tilted rearward, the seat is reared to a smaller degree than the back frame. While leaning
The upper end of the back frame is connected to a backrest ,
The upper part of the back frame can be tilted backward against elasticity with a body pressure caused by a seated person leaning against the backrest centering on a portion located above the lumbar support portion of the backrest . for this reason, the back frame, that obtained tilted backward largely upper than the lower part with locking state,
Chair with backrest. The top and backrest of the back frame is consolidated in the right and left two positions,
The upper part of the back frame can be deformed independently at two places on the left and right sides, and the backrest can be twisted and deformed in plan view by the body pressure of the seated person.
A chair with a backrest according to claim 1.

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