JPH0919340A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a natural sitting feeling without any spring feeling by dealing with the difference of the weight of user's body regardless of the weight difference when a back frame is reclined backward. SOLUTION: This chair is provided with a receiving base 1 provided on the upper parts of legs, a seat frame 2 positioned at the upper part of the receiving base 1 and pivotally attached to the receiving base 1 at the front position, a back frame 3 positioned at the rear part of the receiving base 1, an arm 4 which is fixed at the lower part of the back frame 3 and extended forward and in which the position closer to the back frame 3 is pivotally attached to the rear position of the receiving stand 1, and a link 5 for linking the front position of the arm 4 with the seat frame 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an office chair,
In particular, the present invention relates to a chair that enables a stable sitting while maintaining a posture according to the weight when the backrest tilts.

[0002]

2. Description of the Related Art A chair which has been conventionally used for office work has a backrest provided on its back so that the chair can be tilted back and forth.

A coil spring is generally used to impart elasticity when the backrest is tilted. When the backrest tilts backward, the spring is stretched, and when the backrest tilts forward, the spring returns to its original state. In that case, the strength of the spring is adjusted according to the weight of the seated person, but if the weight difference of the seated person is large, the inclination angle of the backrest will be different, and for example, it is disclosed in Japanese Patent Publication No. 5-62527. As described above, there is provided a device in which the resistance against the rearward leaning of the backrest automatically changes according to the weight of the seated person so that the user can always sit in a stable state.

[0004]

However, in the above structure, when the backrest is tilted backward, the seat frame is tilted forward according to the weight of the seated person so that a stable seating can be achieved. Therefore, the seat frame and the backrest frame are combined. A coil spring is used for the connection, but in this case it is extremely difficult to select a coil spring that satisfies all of the individual occupants with different weights, and there is also a problem of space when the length of the coil spring becomes long. , It was difficult to install. As a result, the chair often has a strong spring feeling and is uncomfortable to sit on.

On the other hand, there is a chair (Japanese Utility Model Laid-Open No. 2-271345) in which the rear part of the seat part is raised and the seat part is moved forward when the backrest is weighted. When the weight is applied to the backrest, the backward inclination of the back due to the joints of the thighs of the body does not match the backward inclination of the backrest of the chair, which makes it impossible to sit in a comfortable position and leaning on the backrest. Since the seat part moves forward, there is a problem that the thigh part of the seated person is squeezed or wrinkles are generated in the pants and the skirt, and the Y-shirt slips out of the pants.

In view of the above, the present invention provides a backrest resistance force corresponding to the body weight without depending on the spring force, and does not cause pressure on the seated person's body or disorder of clothes.
Moreover, it is an object of the present invention to provide a chair that can obtain a stable seated state with a simple configuration having few constituent parts.

[0007]

In order to achieve the above object, the first aspect of the present invention is to provide a pedestal provided on the upper part of the leg and a pedestal located at the upper part of the pedestal and at the front position thereof. A seat frame pivotally mounted, a back frame located at the rear of the pedestal, and a back frame fixed to the lower part of the back frame and extending forward and a position near the back frame is pivotally attached to a rear position of the pedestal. An arm and a link for connecting a front position of the arm to the seat frame. Claim 2 urges the seat frame and the arm in the direction to separate from each other. The auxiliary elastic body is provided.

According to a third aspect of the present invention, there is provided a pedestal provided on the upper part of the leg, a seat frame located on the upper part of the pedestal and pivotally mounted on the pedestal at a front position of the pedestal, and on a rear part of the pedestal. A back frame, an arm fixed to a lower portion of the back frame and extending forward, and a position near the back frame being pivotally attached to a rear position of the pedestal, and one end fixed to a front position of the arm. The end is loosely attached to the seat frame and is provided with a leaf spring that connects the two. In addition, claim 4 is,
In the first or third aspect, the pedestal is provided with an elongated guide hole for guiding the movement of the arm, and the fifth aspect specifies the position where the arm pushes up the seat arm.

According to the above structure, when the seated person is seated on the seat frame via the seat cover and leans against the backrest, the back frame is tilted backward and the arms are rotated. Alternatively, the rear portion of the seat frame is raised via the leaf spring. The backward tilt of the back frame will change according to the weight of the seated person so that if the weight of the person sitting on the seat frame is heavy, the resistance will be large, and if the weight is light, the resistance will be small. It is the most suitable sitting comfort. Further, since the seat frame does not move in the front-rear direction, even if the back frame tilts backward, it does not disturb the clothes and does not cause a feeling of pressure on the body. Further, according to the fifth aspect, it is possible to further prevent the above-mentioned feeling of pressure on the seated person from disturbing the clothes and further improve the sitting comfort.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment shown in FIGS. 1 to 5 includes a pedestal 1 provided on an upper portion of a leg (not shown), and a seat frame 2 positioned above the pedestal 1 and pivotally attached to the pedestal 1 at a front position thereof. And a back frame 3 located at the rear of the pedestal 1, and fixed to a lower portion of the back frame 3 and extending forward, and a position near the back frame 3 is pivotally attached to a rear position of the pedestal 1. Arm 4 and a link 5 that connects the front position of the arm 4 to the seat frame 2.

The pedestal 1 is provided with an elongated guide hole 6 (see FIG. 2) for guiding the movement of the arm 4, and the seat frame 2 and the arm 4 are separated from each other in a direction in which they are separated from each other. An auxiliary elastic body 7 made of a biasing compression spring or rubber is provided.

The left and right upper front ends of the pedestal 1 and the seat frame 2
The left and right mounting plates 8 and 8 fixed to the lower part in front of are pivotally attached at that position by a pair of pins 9 and 9, respectively.

Positions of the pair of arms 4, 4 fixed to the back frame 3 near the back frame 3 and the left and right rear ends of the pedestal 1 are rotatably connected by pins 10, 10.
Further, the link 5 is provided between the front position of the arm 4 and the left and right mounting plates 11 provided at the lower rear part of the seat frame 2.
The link 5 and the mounting plate 11 are connected by a pin 12 and the arm 4 is connected by a pin 13, respectively. And the pin 13 of this link 5 is the pedestal 1
It is possible to move inside the above-mentioned guiding long hole 6 provided in the.

The position connected to the seat frame 2 by the link 5 is a position directly below the greater trochanter of the thigh of the seated person sitting on the cushion 14 on the seat frame 2, and the upper half of the seated person's upper body is It is designed to be pushed up just above.

In the figure, reference numeral 15 indicates a gas spring for vertically moving the pedestal 1.

The operation will be described below. The solid line drawing of FIG. 1 and FIG. 4 show the postures of the seat frame 2 and the back frame 3 of the chair when there is no seated person or when there is a seated person but not leaning against the back frame. In this state, Since the seated person is still sitting on the seat frame 2, the posture of the seat frame 2 does not change. However, when the seated person leans against the back frame 3, the chair is tilted backward as shown by the chain line in FIG. 1 and as shown in FIG. 5, and the rear end of the seat frame 2 rises.

That is, when the back frame 3 tilts backward, the arm 4 rises with the pin 10 as a fulcrum. At this time, the pin 13 of the arm 4 moves upward using the guide elongated hole 6 provided in the pedestal 1 as a guide. As a result, the rear portion of the seat frame 2 connected to the arm 4 via the link 5 rises around the pin 9 pivotally supported by the pedestal 1, and this posture depends on the weight of the seated person. Change. In other words, a heavier person has a larger resistance to the back frame 3 falling down, and a lighter person has a smaller resistance to the back frame 3 to fall, so that the back frame 3 moves according to the weight. Becomes Therefore, the resistance of the backrest corresponding to the weight of any seated person can be obtained, and a comfortable sitting posture can be achieved.

An embodiment according to claim 3 of the present invention is shown in FIGS. 6 and 7. The same parts as those of the embodiment shown in FIGS. 1 to 5 are designated by the same reference numerals, detailed description thereof will be omitted, and only different parts will be described.

That is, a pedestal 1 provided on the upper part of a leg (not shown), a seat frame 2 positioned above the pedestal 1 and pivotally mounted on the pedestal 1 at the front position thereof, and the pedestal 1 A back frame 3 located at the rear of the back frame 3, an arm 4 fixed to a lower portion of the back frame 3 and extending forward, and a position near the back frame 3 pivotally attached to a rear position of the pedestal 1. One end is fixed to the front position of the arm 4 and the other end is the seat frame 2
A leaf spring 16 that is loosely attached to connect the two.

A leaf spring mounting seat 17 having a mountain-shaped side surface is fixed to the upper surface of the arm 4, and a mounting portion 16a on one side of the leaf spring 16 is fastened to the upper surface of the mounting seat 17 by means of a screw or the like. It is fixed by.

The leaf spring 16 is composed of an elongated rectangular leaf spring material, and the central portion 16c is formed to have an inclined surface of about 3 to 4 degrees except for the flat mounting portions 16a and 16b on both sides. The mounting portion 16a has a difference in height between the mounting portion 16b on the other side and the mounting portion 16b on the other side. The mounting portion 16b on the other side has elongated holes 16d and 16d, which are loosely mounted on the seat frame 2 by screws 18 and 18 which are inserted into the elongated holes 16d and 16d. It is installed so that it is at a high position. And both mounting portions 16a, 16b and the central portion 16c
Boundary portions between and are respectively bent portions.

Next, the operation of the above example will be described. When the back frame 3 tilts backward from the state shown in FIG. 6 as shown in FIG. 7, the arm 4 rises with the pin 10 as a fulcrum. As a result, the one side portion 16a of the leaf spring 16 fixed to the mounting seat 17 provided on the arm 4 is lifted, and the central portion 16c.
Is deformed so that it bends upward at the bend, so leaf spring 1
6 is directed upward, and its mounting length is also shortened.

As a result, at the rear portion of the seat frame 2, the pin 13 pivotally supported by the pedestal 1 moves in the elongated hole 6 to assume an ascending posture, which is the same as in the case of FIG. It changes according to weight. Therefore, any seated person can sit in a stable posture corresponding to his / her weight.

[0024]

As described above, according to the present invention, the link spring or the leaf spring is used, and the resistance force when the back frame is tilted is changed according to the weight applied to the seat frame. If the user selects a spring constant and solves the difficulty of the installation location, the weight of the seated person can be sensed and a back reaction force corresponding to that weight can be obtained. The rear inclination can be a stable sitting posture suitable for the person. Further, even if the backrest tilts backward, the seat frame does not move in the front-rear direction, and the rear part moves up and down at that position, which causes problems such as disturbing the clothes of the seated person and pressing the thighs. Absent. Further, since it is not necessary to use an adjustable spring or the like as in the conventional case, the structure is very simple, a large space in the cradle is not required, and a chair with a clean design can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a side view of a main part of the present invention.

3 is a plan view of FIG. 1, where the upper half is a top view and the lower half is a bottom view.

FIG. 4 is a cross-sectional view showing a state in which the back frame of FIG. 1 is unloaded.

FIG. 5 is a cross-sectional view showing a state when tilting in FIG.

FIG. 6 is a cross-sectional view of a main part when no load is applied, showing another embodiment of the present invention.

FIG. 7 is a cross-sectional view showing a state when the back frame of FIG. 6 is tilted.

[Explanation of symbols]

 1 Cradle 2 Seat frame 3 Back frame 4 Arm 5 Link 6 Long hole for guidance 7 Auxiliary elastic body 16 Leaf spring 16a, 16b Attachment part

Claims (5)

[Claims] 1. A pedestal provided on an upper part of a leg, a seat frame located on the upper part of the pedestal and pivotally mounted on the pedestal at a front position of the pedestal, and a spine located on a rear part of the pedestal. A frame, an arm fixed to the lower part of the back frame and extending forward, and a position near the back frame being pivotally attached to a rear position of the pedestal, and a link connecting the front position of the arm to the seat frame. A chair characterized by being provided. 2. The chair according to claim 1, further comprising an auxiliary elastic body that urges the seat frame and the arm in a direction in which they are separated from each other. 3. A pedestal provided on the upper part of the leg, a seat frame located on the upper part of the pedestal and pivotally attached to the pedestal at a front position thereof, and a spine located on the rear part of the pedestal. The frame, an arm fixed to the lower part of the back frame and extending forward, and a position near the back frame being pivotally attached to a rear position of the pedestal, one end fixed to the front position of the arm and the other end seated. A chair comprising: a leaf spring that is loosely attached to the frame and connects the two. 4. The chair according to claim 1, wherein the pedestal has an elongated guide hole for guiding the movement of the arm. 5. The chair according to any one of claims 1 to 4, wherein a push-up point of the seat frame by the arm is located directly below the greater trochanter of the thigh of the seated person.