JP2024034826A - Chair - Google Patents

Abstract

[Problem] To realize a chair that can be reclined without changing the posture of the seated person's head and has excellent computer visibility while maintaining design and functionality. SOLUTION: A backrest 3 includes an upper support 10 and a lower support 7 that are connected to each other so as to be relatively rotatable, the lower support 7 is fixed to a first tilting frame 6, and the upper support 10 The lower end of the second tilting frame 14 is connected to the upper end of the second tilting frame 14 . Although a four-point link mechanism is configured as a whole, the rotation fulcrum 31 of the first tilting frame 6 and the rotation fulcrum 45 of the second tilting frame 14 are different in the front and back, and the relative rotation fulcrum 76 of the backrest 3 and Since the rear pivot point 79 of the lower support 7 is shifted back and forth, the upper support 10 tilts forward relative to the lower support 7 during reclining. [Selection diagram] Figure 10

Description

The present invention relates to a chair having a reclining function (rocking function).

2. Description of the Related Art Reclining chairs whose backrests tilt backward against elastic means are widely used for office use. In this reclining chair, there is a demand for the user to take a relaxed posture with his or her body tilted backwards while viewing a computer monitor (display) placed on the desk without getting tired.

In response to this request, it can be said that it is sufficient to maintain the user's head in a forward posture in the reclined state. In other words, if the backrest is simply tilted back, the user's face will change its posture upward, causing the user's line of sight to shift away from the computer monitor. This puts a strain on the user's head and shoulders, but if the user's head is supported in a forward-facing position in the reclined position, the computer monitor can be viewed without fatigue in the reclined position.

As a technology to meet this demand, Patent Document 1 discloses that the backrest has a high-back specification that also supports the user's head, and that the upper part and the base part below the backrest are bent in side view. By shifting the pivot points of the tilting frame connected to the upper part of the backrest and the tilting frame whose base is fixed in the front-rear direction, the backrest as a whole reclines while the upper part of the backrest is tilted relative to the base. A technique for leaning forward toward a relative body is disclosed.

Patent No. 4015236

In Patent Document 1, the head can be kept in a forward posture when reclining, which is useful when looking at a computer monitor placed on a desk for a long time, but the upper part of the backrest and the base are connected by an axis. Therefore, it can be said that the movement is accurate and the body support function is excellent, but the tilting frame connected to the upper part of the backrest is arranged in an inclined position on both the left and right sides of the seat, which may give people a sense of discomfort. There are concerns.

The present invention was made against the background of this current situation, and aims to disclose a chair that provides excellent visibility of a personal computer in a reclined state while ensuring beauty and accuracy of movement.

The present invention includes various configurations, typical examples of which are specified in each claim. Among these, the invention of claim 1 is:
"It has a backrest that tilts backwards against elasticity,
The backrest includes an upper support body and a lower support body that are connected to each other so as to rotate relative to each other in the front and back direction about a connecting shaft as a fulcrum;
a back plate attached to the front surface of the upper support and the lower support;
a first tilting frame to which the lower support is attached;
a second tilting frame connected to the upper support such that the upper support and the lower support tilt backward together and the upper support rotates forward relative to the lower support; , is equipped with
The second tilting frame is connected to a lower portion of the lower support.
The structure is as follows.

In the present invention, the upper support body and the lower support body constituting the backrest constitute a strength member, and either a frame structure product with openings in the front and rear or a plate-shaped shell structure product can be adopted.

The invention of claim 2 is a development example of claim 1,
“The upper and lower supports are formed into a frame shape with openings in the front and rear, and the back plate is made of a material that can be flexibly deformed, with a portion overlapping the upper support and a portion overlapping the lower support. It is a continuous series.”
The structure is as follows.

The invention of claim 3 embodies claim 1 or 2,
“Both the tilting frames are connected to a base provided in the state of a leg device and are configured to tilt backward,
The pivot point of the first tilting frame is located behind the pivot point of the second tilting frame, and the connection point between the second tilting frame and the lower support is further than the connection point between the upper and lower supports. It's located at the back."
The structure is as follows.

The invention of claim 4 embodies claim 3,
"A rearwardly extending portion is provided at the lower end of the lower support, and the rearwardly extending portion and the upper end of the second tilting frame are connected to be relatively rotatable."
The structure is as follows.

The invention of claim 5 embodies claim 4,
"The lower support body has vertical and longitudinal left and right side members, an upper member connected between the upper ends of the side members, and a lower member connected between the starting ends of the side members, and the lower member The rearwardly extending portion is formed by pressing and bending the rearwardly bent portion.
The structure is as follows.

The invention of claim 6 is a specific example of any one of claims 1 to 3,
"The first tilting frame is integrally provided at the left and right ends of the lower support, and the second tilting frame is disposed between the left and right first tilting frames when viewed from the front."
The structure is as follows.

The invention of claim 7 is a specific example of claim 6,
"It is equipped with a reclining control device that restricts rotation of the second tilting frame."
The structure is as follows.

The invention of claim 8 embodies claim 1,
"The backrest has a high back design, and an upper rest that can support the head or neck of the person seated is arranged such that at least the lower part is located in front of the upper end of the backrest."
The structure is as follows.

In the invention of claim 1, since the upper support member rotates forward relative to the lower support member when reclining, the user can recline while maintaining the posture of his head with his eyes directed toward the computer monitor placed on the desk. This allows you to work on your computer while maintaining a comfortable posture while reducing the strain on your neck and shoulders. Therefore, it is suitable as an office chair. Further, since the second tilting frame is arranged below the upper support body, the chair as a whole becomes compact and looks good.

When the back plate is formed into only one piece that is vertically continuous as in claim 2, the back plate looks good because it is a single piece. In addition, since the back plate as a whole flexes and deforms, it can improve its close contact with the body and soften the contact with the body. Additionally, since the upper and lower supports are frame-shaped with openings at the front and back, the bending function of the back plate can be enhanced to improve fit and cushioning properties.

According to a third aspect of the present invention, a four-point link mechanism is constructed, and accurate and smooth movement can be realized. In this regard, if the configuration of claim 4 is adopted, a four-point linkage mechanism can be constructed by effectively utilizing the upper support body, so that accurate movement can be realized while creating a design that does not give an unnatural feeling.

Moreover, in the invention of claim 5, since the upper support body has a loop structure, it is possible to prevent the strength of the upper support body from decreasing. In addition, the lower member of the upper support body does not touch the back of the person, resulting in excellent cushioning and fit.

In the structure of claim 6, since the second tilting frame protruding rearward is closer to the left and right intermediate portions, it is compact and has high marketability. In the structure of claim 7, since the second tilting frame constituting the link mechanism can also be used as the reclining control means, there is an advantage that the number of members can be reduced to that extent and costs can be suppressed.

By providing an upper rest as in claim 8, it is possible to support the head in an upright position in a reclined state, thereby reducing strain on the neck and shoulders and reducing fatigue when operating a computer on a desk while taking a relaxed posture. It can be ensured that In this case, while the backrest has a high back specification, the upper rest is placed in front of the backrest, so it is possible to achieve a clean appearance as if the upper rest were integrated with the backrest.

They are diagrams showing the appearance of the embodiment, in which (A) is a perspective view seen from the front and above, (B) is a front view, and (C) is a perspective view seen from the rear and front. (A) is a perspective view seen from the rear and below, and (B) is a side view. (A) is a rear view, and (B) is a perspective view seen from below. FIG. 3 is a perspective view with the seat section separated. FIG. 3 is an exploded perspective view of the back. It is a figure which shows the connection structure of a lower support body, (A) is an exploded perspective view, (B) is an isolated side view. It is a figure which shows the connection means of a lower support body, (A) is an exploded perspective view, (B) is a perspective view seen from below. It is a figure which shows the attachment structure of the gas cylinder for tilt control, (A) is an exploded perspective view seen from the rear upper part, and (B) is an exploded perspective view seen from the rear lower part. (A) is an exploded view of the tilting frame and the upper support body, (B) is an exploded perspective view of the upper part of the second tilting frame, and (C) is a plan view of the second tilting frame. It is a side view for showing movement.

Next, embodiments of the present invention will be described based on the drawings. In the following, words such as front and back and left and right will be used to specify the direction, but this direction is defined as the direction seen from a person sitting normally on a chair. The front view is a view seen from the direction facing the seated person.

(1).Overall overview First, an overview of the chair will be explained. This embodiment is applied to a rotary chair for office use. The chair includes a leg device 1, a seat 2, and a backrest 3 as basic elements. The leg device 1 has a structure in which a leg support 4 made of a gas cylinder is erected at the center of a base having five leg blades, and a caster is provided at the tip of each leg blade.

As shown in FIG. 2, a base 5 is fixed to the upper end of the leg support 4, and the lower tips of the left and right first tilting frames 6 are connected to the base 5. As shown in FIGS. 2(A) and 3, the first tilting frame 6 extends rearward from the base 5 and stands up while expanding outward from the left and right. It constitutes a lower support body 7. That is, the first tilting frame 6 and the lower support 7 partially share members, and the upper part of the first tilting frame 6 serves as a side member 8 of the lower support 7.

The lower end of the lower support body 7 is comprised of a left and right longitudinal lower member 9. That is, the lower support body 7 is constructed by connecting the rising portions of the left and right first tilting frames 6 with the lower member 9.

The lower end of the upper support 10 is connected to the upper end of the lower support 7 . The upper support body 10 has a loop structure including left and right side members 11, an upper member 12 connected to the upper ends thereof, and a lower member 13 connected to the lower ends of the left and right side members 11. Therefore, in this embodiment, the upper and lower supports 7 and 10 are in the form of a frame body that is open in the front and rear.

The lower ends of the left and right side members 11 of the upper support body 10 are connected to the upper ends of the side members 8 of the lower support body 7 so as to be tiltable backward. On the other hand, the lower member 13 of the upper support body 10 projects backward, and the upper end of the second tilting frame 14 is connected to the backwardly projecting lower member 13 so as to be tiltable backward. The lower end of the second tilting frame 14 is connected to the rear part of the base 5.

The backrest 3 also includes a backboard 15 made of a flexible resin material such as elastomer, and an upholstery (skin material) 16 stretched on the front surface of the backboard 15. Since the back plate 15 is made of a flexible resin material, it has excellent fit to the body of a seated person. Furthermore, during reclining, the upper support 10 and the lower support 7 rotate relative to each other, and the elastic deformation of the back plate 15 allows the relative rotation of both supports 10 and 7.

An upper rest 17 that supports the head and neck of the seated person is attached to the upper end of the backrest 3 so that its height can be adjusted. The upper rest 17 is attached to the upper member 12 of the upper support 10 via a bracket device (not shown). When the backrest 3 is reclined, the upper support 10 rotates forward relative to the lower support 7, but since the seated person's head is supported by the upper rest 17, the person's line of sight toward the computer monitor on the desk is not affected. It can be reclined without changing.

The tilting frames 6 and 14 and the upper support body 10 can be die-cast products of light metal such as aluminum, or molded products of engineering plastic. It is also possible that the first tilting frame 6 (and lower support 7) and the second tilting frame 14 are made of aluminum, and the upper support 10 is made of synthetic resin.

As shown in FIGS. 2(A) and 3, an upward lumbar post 18 is integrally formed at the left and right intermediate portions of the lower member 9 constituting the lower support body 7. A lumbar pad 19 that hits from behind is attached so that its height can be adjusted freely. The lumbar pad 19 supports the seated person's lumbar region (particularly around the third lumbar vertebrae) from behind.

(2) Seat part/first tilting frame The details of each part will be explained below with reference to the drawings from FIG. 4 onwards. As shown in FIG. 4, the seat 2 includes a seat inner shell (seat plate) 20 made of resin and a cushioning material 21 overlaid on the upper surface thereof, and the cushioning material 21 is covered with an upholstery 22.

As shown in FIG. 4, the seat 2 is fixed to a seat support plate (seat outer shell) 23 made of resin and placed below the seat support plate 23. It can move back and forth and is supported in a way that cannot be removed. The intermediate member 24 includes a front and rear longitudinal side frame portion (bank portion) 24a that constitutes a back side portion thereof, and a handle (knob) for moving the seat 2 back and forth in the front portion of the side frame portion 24a. I am wearing 25. Note that the seat 2 can be adjusted by moving back and forth while the person is still seated on the seat.

As shown in FIG. 4, a left and right longitudinal front member 26, which is close to the left and right width of the seat 2, is connected to the front end of the base 5 so as to rotate about the left and right longitudinal axis. Angular front protrusions 27 are provided at both ends to protrude upward, while an outwardly projecting portion 6a (for example, see FIG. 7(B)) is provided at a portion of the first tilting frame 6 located below the rear of the seat 2. An upward rear protrusion 28 is formed at the tip of the outwardly extending portion 6a.

The side frame portions 24a of the intermediate member 24 are connected to these front and rear projections 27, 28 by left and right longitudinal pins (not shown). Therefore, when the first tilting frame 6 tilts backward, the seat 2 tilts backward while retreating, but the degree of backward tilting is smaller than that of the first tilting frame 6. As shown in FIGS. 6(A) and 8(B), a lower cover 5b is attached to the lower surface of the base 5. As shown in FIG.

As shown in FIG. 4, the intermediate member 24 is formed with a large relief hole 29 that opens upward and downward. Further, the seat support plate 23 is also formed with an escape hole 29 that opens upward and downward. Note that behind the handle 25 for moving the seat 2 back and forth, a lift lever 30 for adjusting the height of the seat 2 is arranged.

As shown in FIG. 6, a square (hexagonal) first support shaft 31 is mounted between the front ends of the first tilting frame 6. As shown in FIG. The first support shaft 31 is held so as not to rotate relative to the first tilting frame 6, and is rotatably held in a bearing hole 32 provided in the side plate 5a of the base 5 via a bush 33. Further, a downwardly extending load receiving arm 34 is attached to the left and right intermediate portions of the first support shaft 31 so as to be relatively non-rotatable. The load receiving arm 34 is tilted backward in side view so as to shift forward as it goes downward.

The load receiving arm 34 is disposed inside the base 5, and a spring unit 35 whose rear end is brought into contact with the front surface of the load receiving arm 34 is disposed inside the base 5. The front end of the spring unit 35 is connected to the base 5 by a left and right longitudinal shaft 36, and as the spring unit 35 rotates and the point of load application to the load receiving arm 34 changes in the vertical direction, the rear of the backrest 3 The strength of resistance to tilting changes.

The angle adjustment of the spring unit 35 is performed by rotating a cam (peripheral cam) 37 shown in FIGS. 7(A) and 6(B). The cam 37 is horizontally rotatably mounted on the upper surface of the base 5 at a position behind the spring unit 35, while a slider 38 is mounted on the upper surface of the spring unit 35 so as to be movable back and forth but cannot be removed upwardly. A cam 37 is in contact with the rear end of a relay member 40 connected to the slider 38 by left and right longitudinal pins 39 from behind.

The relay member 40 is attached to the base 5 so as to be movable back and forth without being able to move up and down. When the cam 37 rotates, the relay member 40 moves back and forth, changing the tilting posture of the spring unit 35, and preventing the backrest 3 from tilting backwards. The strength of resistance changes. As shown in FIGS. 6A and 7A, the slider 38 is urged in the backward direction by a spring 41. The rotation of the cam 37 is performed by rotating the elastic adjustment handle 42 shown in FIG. 2(A). The rotational torque of the elastic adjustment handle 42 is transmitted to the cam by a wire (not shown) (a wire inserted through a tube).

(3).Second Tilting Frame As clearly shown in FIG. 7, the lower part of the second tilting frame 14 is formed into a bifurcated shape, and a left and right longitudinal second support shaft 45 is fixed to the tip thereof. The second support shaft 45 is held by upper and lower bearings 46 and 47 that are divided into two parts, and the upper and lower bearings 46 and 47 are fitted from above into an upward opening groove 48 formed at the rear of the base 5. The cover plate 49 is fixed to the base 5 with screws and is held in such a way that it cannot be separated. Therefore, the second tilting frame 14 rotates (tilts) using the second support shaft 45 as a fulcrum.

Tilt control of the backrest 3 is performed by a back gas cylinder 50 shown in FIGS. 7 and 8. That is, the back gas cylinder 50 switches between a state in which the backrest 3 freely reclines and a state in which it is held in an arbitrary posture.

As clearly shown in FIG. 8(B), a bracket 51 having left and right side plates is fixed to the tip of the piston rod constituting the back gas cylinder lid 50, while a bracket 51 having left and right side plates is fixed to the middle part of the rear end of the base 5. A bearing rib 52 sandwiched between the bracket 51 of the back gas cylinder lid 50 is integrally formed, and the bearing rib 52 and the bracket 51 are connected by left and right longitudinal support shafts 53. On the other hand, the upper rear end of the back gas cylinder lid 50 is connected to a bearing boss 54 provided at the bifurcated base of the second tilting frame 14 by a left and right longitudinal pin 55.

A case 56 is attached to the lower end of the back gas cylinder 50, and a lever member (not shown) for pushing and operating the bush valve of the back gas cylinder 50 is attached to the case 56. It rotates by pulling the tilting operation wire inserted into the tube. The pulling operation of the tilting operation wire is performed by the tilting control lever 57 shown in FIGS. 2(A) and 2(B). The tilt control lever 57 is attached to the right side frame portion 24a of the intermediate member 24 behind the elastic adjustment handle 42.

(4) Structure of backrest As can be understood from FIG. 5, the side members 11 and upper members 12 that constitute the upper support body 10 are in the form of a channel having a groove that opens forward. The side members 8 and lower members 9 of the lower support body 7 are also formed in a channel shape with forward openings.

On the other hand, a downwardly open U-shaped upper reinforcing body 60 that fits into the groove of the upper support body 10 is integrally fixed to the rear surface of the outer peripheral part of the upper half of the back plate 15 by insert molding. A downwardly open U-shaped lower reinforcing body 61 that fits into the groove of the lower support body 7 is integrally fixed to the rear surface of the outer periphery of the lower half part by insert molding. The upper and lower reinforcing bodies 60 and 61 are molded products made of synthetic resin such as polypropylene, and there is a slight gap between the upper and lower reinforcing bodies 60 and 61. Therefore, relative rotation between the upper support 10 and the lower support 7 is allowed.

Although not shown, the back plate 15 is fixed to the upper support 10 and the lower support 7 by screws inserted through the back plate 15 and the reinforcing bodies 60, 61 from the front. What is indicated by the reference numeral 62 in FIG. 5 is a boss into which a screw is screwed.

The backrest 3 includes an upholstery 16, and the outer periphery of the upholstery 16 is sewn and fixed to an upper edge member 63, an intermediate edge member 64, and a lower edge member 65 made of synthetic resin. The upper edge member 63 is formed into a U-shape with a downward opening when viewed from the front, the left and right intermediate edge members 64 are formed into a plate shape, and the lower edge member 65 is formed into a U-shape with an upward opening when viewed from the front.

Although not shown, the edge members 63, 64, and 65 are formed with engaging claws that project backward, while the back plate 15 and the reinforcing bodies 60, 61 are provided with engaging claws that engage and disengage. A hole 66 is formed. Further, as can be understood from FIG. 5, a rib 67 that projects forward is formed on the outer periphery of the back plate 15. Therefore, the front surface of the portion of the back plate 15 that is closer to the outer periphery is a stepped surface 68 that is lower than the rib 67. Edge members 63, 64, and 65 overlap the stepped surface 68, and the upholstery 16 is set so as not to protrude in front of the ribs 67.

As shown in FIG. 5, a rectangular rectangular notch 69 is formed in the upper left and right middle parts of the upper end of the upper edge member 63, and is formed between the upper left and right middle parts of the back plate 15 and the upper right and left middle parts of the upper reinforcing body 60. A rectangular escape hole 70 is formed in the left and right sides. These notches 69 and relief holes 70 are for allowing a bracket (not shown) for attaching the upper rest 17 to escape.

As shown in FIG. 1, the upper rest 17 includes a base plate 71 made of elastomer, a main frame 72 with front and rear openings placed behind the base plate 71, and an upholstery 73 overlaid on the front surface of the base plate 71. The outer periphery of the upholstery 73 is fixed to a loop-shaped edge member 74 by sewing or the like. The board 71 is fixed to the main frame 72 by insert molding. Further, the edge member 74 is provided with a large number of backward boss shafts (not shown), and the main frame 72 is provided with a group of boss cylinders into which the boss shafts are fitted.

Note that the design of the upper rest 17 can be developed in various ways. For example, it is possible to adopt a mesh specification, or a specification in which the shell body is covered with a seat cushion material. When a soft substrate 71 is used as in the embodiment, the surface can be embodied in various patterns such as a lattice pattern, a polka dot pattern, and a tortoiseshell pattern. A plain structure with no pattern can also be used. The upholstery 73 may be omitted.

(4).Connection structure of upper and lower frames As shown in FIG. 9(A), plate-shaped male bearings 75a are integrally formed at the upper ends of the left and right side members 8 constituting the upper support body 10. A female bearing part 75b into which a male bearing 75a enters from below is integrally formed at the lower end of the side member 11 in the upper support body 10. connected. The first pin 76 is fixed to the upper support body 10 by a screw (not shown).

As shown in FIG. 9(B), the second tilting frame 14 has a gutter-like shape that opens forward, and has a forward-facing bearing boss body 77 integrally formed at its upper end. The lower member 13 of the body 10 is provided with bearing ribs 78 projecting downward that sandwich the bearing boss body 77 from the left and right sides, and these bearing boss bodies 77 and the left and right bearing ribs 78 are connected by left and right longitudinal second pins 79. ing.

A cover (lid) 80 that encloses the connecting portion is attached to the upper end of the second tilting frame 14 . The cover 80 has a front plate 81 that covers the bearing boss body 77 and the bearing rib 78 from the front, and left and right side plates 82 that surround the bearing rib 78 from the left and right outer sides, and the front plate 81 has a large cutout downward. . Inside the second tilting frame 14, on both the left and right sides of the bearing boss body 77, a pair of regulation plates 77a on the left and right sides, which are trapezoidal in side view, are protruded forward. is positioned.

A side plate 82 of the cover 80 is provided with a pair of upper and lower guide ribs 83 into which the ends of the second pins 79 fit. Further, upward engaging claws 84 are formed by notching the left and right side parts of the front plate 81 of the cover 80, and the upward engaging claws 84 engage the bearing ribs 78 from below, so that the cover 80 It is held in such a way that it cannot be removed with a light force.

(5).Summary In the above configuration, as shown in FIG. 10, the first tilting frame 6 and the lower support 7 tilt backward about the first support shaft 31, and the second tilting frame 14 The front parts of the upper support 10 and the lower support 7 rotate relative to each other in side view using the first pin 76 as a fulcrum, and the upper support 10 and the second tilting frame 14 rotates relative to the second pin 79 as a fulcrum (in order to clarify the position of the connecting part of the tilting frames 6 and 14 in FIG. (displayed shifted).

Since the first support shaft 31 and the second support shaft 45 are shifted back and forth, and the second pin 79 is located below and behind the first pin 76, the first support shaft 31 and the second support shaft 45 are shifted from each other. The angle θ1 formed by the upper support body 10 with respect to the line segment connecting the first pin 76 becomes smaller in proportion to the increase in the reclining angle θ1. Therefore, the backrest 3 as a whole is tilted backward, while the upper support 10 is raised relative to the lower support 7.

As a result, it is possible to prevent or suppress the side view posture of the head from changing when reclining, and to face the personal computer monitor on the desk. When the upper rest 17 is used as in the embodiment, the head (or neck) can be supported stably, which can contribute to reducing the burden on the neck and shoulders.

In other words, the seated person can view the computer monitor at an appropriate angle while resting his or her head on the upper rest 17, which reduces strain on the neck and shoulders and allows the person to work on the computer while maintaining a comfortable state. I can do it. It is particularly preferable if the height of the upper rest 17 can be adjusted as in the embodiment, since the head can be maintained in an optimal posture.

In the embodiment of the present application, since the first tilting frame 6 and the lower support body 7 are integrated, there is an advantage that the number of members can be reduced and movement can be ensured. Further, since the lower member 13 of the lower support body 7 is a rearward projecting portion, a four-point linkage mechanism can be easily realized using the loop-structured upper support body 10. Therefore, quality can be stabilized while ensuring high strength. Since the lower member 13, which is a rearward projecting portion, can be grasped by a person, the chair can be easily moved. That is, the lower member 13 can be used as a pull.

The second tilting frame 14 protrudes a little behind the lower support 7, but since only one second tilting frame 14 is placed between the left and right sides, it becomes an obstacle for people walking near the chair. It will never become. That is, it is possible to prevent pedestrians and luggage from getting caught in the second tilting frame 14.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, the seat does not necessarily have to be linked to the backward tilting of the backrest. The backrest can also have a structure in which cushioning material is layered on a resin inner shell.

In order to facilitate bending and deformation of the back plate, it is also possible to partially thin the back plate to form a hinge portion. It is also possible to adopt a structure in which the back frame is covered with mesh material. The first tilting frame, the second tilting frame, and the frame that constitutes the backrest can be embodied in various ways as long as they perform their functions.

The present invention can be embodied in a chair. Therefore, it can be used industrially.

1 Leg device 2 Seat 3 Backrest 5 Base 6 First tilting frame 7 Lower support 8 Side member of lower support 10 Upper support 11 Side member of upper support 13 Lower member which is an overhang of upper support 14 Second Tilt frame 15 Back plate 16 Upholstery (skin material)
17 Upper rest (headrest)
31 First support shaft 45 Second support shaft 76 First pin 79 Second pin

Claims (8)

It has a backrest that tilts backward against elasticity,
The backrest includes an upper support body and a lower support body that are connected to each other so as to rotate relative to each other in the front and back direction about a connecting shaft as a fulcrum;
a back plate attached to the front surface of the upper support and the lower support;
a first tilting frame to which the lower support is attached;
a second tilting frame connected to the upper support such that the upper support and the lower support tilt backward together and the upper support rotates forward relative to the lower support; , is equipped with
the second tilting frame is connected to a lower part of the lower support;
Chair. The upper and lower supports are formed into a frame shape with openings in the front and rear, and the back plate is made of a material that can be flexibly deformed, and the part overlapping the upper support and the part overlapping the lower support are continuous. Continuous to
A chair according to claim 1. Both of the tilting frames are connected to a base provided in the state of a leg device and are configured to tilt backward;
The pivot point of the first tilting frame is located behind the pivot point of the second tilting frame, and the connection point between the second tilting frame and the lower support is further than the connection point between the upper and lower supports. located at the back,
The chair according to claim 1 or 2. A backward projecting portion is provided at the lower end of the lower support, and the backward projecting portion and the upper end of the second tilting frame are connected to be relatively rotatable.
A chair according to claim 3. The lower support has vertical and longitudinal left and right side members, an upper member connected between the upper ends of the side members, and a lower member connected between the starting ends of the side members, and the lower member The rearwardly extending portion is formed by being bent backwardly.
A chair according to claim 4. The first tilting frame is integrally provided at the left and right ends of the lower support, and the second tilting frame is disposed between the left and right first tilting frames when viewed from the front.
The chair according to claim 1 or 2. comprising a reclining control device that restricts rotation of the second tilting frame;
A chair according to claim 6. An upper rest capable of supporting the head or neck of a seated person is arranged such that at least a lower portion thereof is located in front of the upper end of the backrest.
A chair according to claim 1.

Images