JPH0225324Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a chair that reclines as the rear end of the seat lowers while keeping the height of the front end of the seat constant.

(Prior art) The rear end of the seat moves down a predetermined distance about the pivot that supports the front end of the seat, that is, the rear end of the seat lowers to a predetermined height while keeping the height of the front end of the seat constant. Chairs are already known that are equipped with a reclining mechanism in which the backrest tilts at a predetermined angle as the rear end of the seat lowers.

This type of chair has the advantage that the height of the front end of the seat is constant, so that even if the user sits for a long time on a chair with a tilted backrest, the legs will not get tired.

Incidentally, in recent years, various studies have been made on chairs from the standpoint of ergonomics, and improvements have been made depending on the purpose of use of various chairs.
The inventor of the present invention also investigated the above-mentioned chair equipped with the reclining mechanism from the above point of view, and as a result found problems, and devised the present invention to solve the problems.

In other words, in a chair where the backrest is erect and the angle of the backrest is adjusted correctly relative to the seat surface, there is no undue pressure on the vertebral bodies and intervertebral discs of the human body's back column, and the user feels less fatigued even when sitting for a long time. However, when the backrest is tilted, especially the third
Excessive pressure (load) is applied to the intervertebral discs and the fourth intervertebral disc, and sitting for long periods of time can cause fatigue and even lower back pain.

With the recent development of FA, centralized monitoring work has been newly added to chair work. The above-mentioned problems cannot be ignored because this monitoring work requires sitting for a long time with the backrest tilted and the head held up.

(Purpose) The main purpose of the present invention is to provide a chair that is more user-friendly and can provide more appropriate support to the seated person by improving the chair equipped with the above-mentioned reclining mechanism. There is a particular thing.

Another object of the present invention is to provide a chair with less fatigue even when sitting for a long time with the backrest tilted or tilted.

(Structure) For this purpose, in the present invention, in a chair whose backrest tilts backward as the rear end of the seat descends, the backrest is fixed and is slidably attached to the upper part of the guide column. a movable frame, and a crank member having an articulation point, one end of which is attached to the lower end of the guide column, and the other end of which is pivoted to one end side of a threaded rod extending in the moving direction of the movable frame. The movable frame is characterized in that the movable frame has an operating rotating body that is screwed onto the threaded rod and rotates without being displaced relative to the movable frame.

With this configuration, when the operating rotating body supported by the movable frame is rotated, the operating rotating body is displaced relative to the threaded rod according to the amount of rotation, and the operating rotating body and the movable frame are rotated. The backrest attached to the movable frame moves up and down in accordance with the amount of rotation of the operating rotary body.

Therefore, the seated person can rotate the operating rotating body by placing his or her hand behind the backrest while seated, and adjust the height of the backrest to a desired height to obtain appropriate support. In addition, since the backrest moves up and down according to the amount of rotation of the operating rotary body, the height of the backrest can be finely adjusted. It becomes possible to make it appropriate.

An embodiment of the chair according to the present invention will be described below based on the drawings.

(Example) Figures 1 and 2 show the framework of the chair with the seat and backrest cushions removed. , coil springs, etc. are omitted.

In the figure, 1 is a support for the seat. The support 1 is
It has a shape that extends forward from the base 1a that is fitted into the support column 2 and projects on both sides. Both projecting ends 1b, 1b of the support body 1 pivotally support the front ends of the mounting frames 3, 3 by support shafts 5, 5. The seat A is attached to the mounting frames 3, 3.

The rear end of each mounting frame 3 pivotally supports the central bent portion 7a of the dogleg-shaped guide column 7 with a pin 9. One side of a pair of bell cranks 10 is pivotally attached to the lower end of each guide column 7 via a shaft 11.

The bell crank 10 is attached to the support body 1 via the support shaft 12.
It is attached to and can swing around a support shaft 12. Connecting rod 1 on the other side of bell crank 10
4 are connected via a joint shaft, and a threaded rod 18 having a pin 16 as a pivot is attached to the tip of the connecting rod 14.

This pair of bell cranks 10, 10 and connecting rod 14
are connected at a joint point to form a crank member.

On the other hand, as shown in an enlarged view in FIG.
In 7b, there is a movable frame 2 that straddles both the upright parts 7b and 7b.
0 is attached.

The movable frame 20 has a structure in which two members are integrated by fixing with bolts, and guide columns 7 are provided on both sides of each member.
The claws 20a, 20a, which are arranged at intervals in the longitudinal direction of the guide rail 7c projecting outward
...is provided. The claws of one member and the claws of the other member are arranged alternately in the longitudinal direction of the guide rail 7C, and each claw 20a is in sliding contact with the guide rail 7c. Thereby, the movable frame 20 is guided by the guide column 7 and can move up and down. A backrest B is attached to the front surface of this movable frame 20.

An operating rotating body 22 is screwed onto a threaded rod 18 extending centrally between the guide columns 7, 7. The operating rotating body 22 is supported by the movable frame 20 so that it cannot be displaced in the direction in which the threaded rod 18 extends, and when the operating rotating body 22 is displaced relative to the threaded rod 18 by rotating the operating rotating body 22. The movable frame 20 is guided by the guide column 7 and moves up and down together with the operating rotating body 22.

On the other hand, when the rear end of the mounting frame 3 descends around the support shaft 5, that is, when the rear end of the seat A descends around the support shaft 5, the guide column 7, which is connected to the mounting frame 3 by the pin 9, The upright portion 7b is tilted or tilted rearward. Along with this, the threaded rod 18 is pulled down by the action of the bell crank 10 pivotally connected to the guide column 7, and the movable frame 20 moves the guide column 7.
It will be lowered accordingly. For this reason, the backrest B is pulled down as the backrest B tilts or tilts, thereby preventing the unpleasant so-called shirt lifting.

Erecting the backrest B of a chair equipped with such a frame,
The tilting movement is performed using a gas spring 24 and a compression coil spring 25.

The gas spring 24, as shown in FIG.
Its tip 24a is pivotally connected to the support 1 via a pin 26, and the actuating rod 28 extending from the gas spring 24 is pivotally attached above the central bent portion 7a of the guide column 7 via a pin 30.

On the other hand, the compression coil spring 25 is suspended between the shaft 11 and the tip of the support 1. With the assisting force of the compression coil spring 25, the backrest B is guaranteed to return to its upright position (the rear end of the seat A returns to its raised position).

(Effects) As explained above, according to the present invention, at any tilt angle of the backrest, the seated person can finely adjust the height of the backrest by placing his/her hand behind the backrest and operating the operating rotating body. This provides appropriate support, making the chair less tiring even when sitting for long periods of time.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the frame of the embodiment, Fig. 2 is a side view schematically showing the frame shown in Fig. 1, and Fig. 3 is a side view schematically showing the frame shown in Fig. 1.
The figure is an enlarged perspective view of the main parts of the backrest height adjusting means. A...Seat, B...Backrest, 5...Spindle, 7
...Guiding column, 18...Threaded rod, 20...Movable frame, 22...Operation rotating body.

Claims (1)

[Claims for Utility Model Registration] Seat mounting frame 3 that lowers the rear end of the seat A around the support shaft 5 located at the front end of the seat support 1 as the center of rotation.
and a guide column 7 that is pivotally supported at the rear end of the mounting frame and tilts the backrest B when the seat is rotated, and the backrest tilts backward as the rear end of the seat lowers. A movable frame 20 is fixed to B and is slidably attached to the upper part of the guide column 7.
and has a joint point, one end is attached to the lower end of the guide column 7 and interlocks with the guide column 7, and the other end is pivotally attached to one end side of a threaded rod 18 extending in the moving direction of the movable frame 20. crank members 10 and 14 are provided, the movable frame 20 is screwed onto the threaded rod 18;
Operation rotating body 2 that rotates without being displaced relative to the movable frame
A chair comprising: 2.