1, the seat height refers to the vertical distance from the seat surface to the ground; If the seat surface is inclined backward or concave arc, the seat height refers to the vertical distance from the center of the front edge of the seat to the ground. If the seat height is too high, the legs will be suspended and the thigh blood vessels will be oppressed; Too low will cause physical fatigue.

2. Practice has proved that the appropriate seat height is the height from the calf socket to the sole plus the heel thickness of 25-35mm, and then minus the activity margin 10-20mm. Namely: seat height H = calf socket height+heel thickness-appropriate clearance.

3. The national standard GB 3326- 1997 stipulates that the seat height H is 400-440mm and the size difference is 10mm. The maximum height of the soft seat surface is 460mm (excluding the subsidence of the seat surface). The height of the sofa seat can be lower, so that the legs extend forward and lean back, which is beneficial to the natural state of the spine. The height of the sofa is generally 360-420mm.

Second, the size standard of the seat depth of the chair.

1, the seat depth refers to the distance from the front edge to the rear edge of the seat. Too deep and too shallow will make the calf and back tired and uncomfortable. Practice has proved that the sitting depth should be slightly less than the horizontal length of thigh when sitting. That is, the sitting depth T= the horizontal length of sitting thigh exceeds 60mm (gap).

2. The national standard GB 3326- 1997 stipulates that the seat depth T is 340-420mm (armchair) or 400-440mm (folding chair), and the size difference is 10mm. Leisure seats such as sofas can be slightly deeper, 480-560mm, because the backrest is inclined.

Third, the seat width size standard of the chair.

1, the width of the seat should allow the arm to be fully supported, leaving room. For an armchair, the inner width of the armrest is the seat width, which is generally determined by the average shoulder width of a person plus an appropriate margin. Namely: the inner width of the front edge of the handrail B= the shoulder width of the human body+the thickness of winter clothes+the activity allowance.

2. The national standard GB 3326- 1997 stipulates that the front width B of armchair or folding chair seat is greater than or equal to 380mm, and the size difference is10 mm; ; The inner width b of the front edge of the handrail is greater than or equal to 460mm, and the size difference is 10 mm.

Chair size standard seat inclination and backrest inclination.

1, and the angle between the seat surface and the horizontal plane is called the seat inclination angle α; The included angle between the backrest and the horizontal plane is called the reclining angle β.

2. The national standard GB 3326- 1997 stipulates that the seat inclination angle α is 1-4 degrees (armchairs and armchairs) or 3-6 degrees (folding chairs), and the angle gradient is 1 degree; The backrest inclination β is 95- 100 degree (armchair and armchair), or 1 00-10 degree (folding chair), and the angle difference is1degree. For sofa, α is 3-6 degrees and β is 98- 1 12 degrees; The recliner is bigger.

5. Height of backrest of standard chair size.

1. The minimum height of chair backrest can be set at the first and second lumbar vertebrae (working chair), and the length can be gradually increased, reaching the scapula and neck (leisure chair) at the highest. When resting statically, the backrest length can be required to support the head (leisure chair). Practice has proved that the best supporting point of backrest is about 250 mm

2. The national standard GB 3326- 1997 stipulates that the backrest height L is greater than or equal to 275mm, and the size difference is10 mm. ..

Extended data

Ordinary chair:

1, coffee chair.

Sun Han Kwon, a Korean designer, designed the coffee chair with the back of the chair designed as the outline of a coffee cup, and the handle part of the cup can be used to hang clothes, bags and other things. There are three colors: black, white and brown, which are very suitable for coffee shops.

2. Armchair.

A general term for armchairs with armrests, except round back chairs and top chairs, the rest are called armchairs. Its style and decoration are simple and complicated, and it is often matched with the coffee table. There are four chairs and two chairs on both sides of the hall, which are displayed symmetrically.

3. Massage chair.

The principle of massage chair is to imitate manual massage, but it uses mechanical rolling force and mechanical force to massage. The massage chair can massage deeply along the spine according to the curve of the human body, such as swinging, shiatsu, pinching, pushing and kneading. When people sit in massage chairs and enjoy the whole body relaxation, it is as if someone is rubbing their backs and shoulders for them.

4. swivel chair.

The upper part is not much different from the general chair, except that there is a rotating shaft called "one leg" under the chair surface, and the human body can rotate left and right at will when leaning. The swivel chair appeared not too early, and it was a kind of chair that China furniture absorbed foreign styles earlier.

5, rocking chair.

A chair that can swing back and forth. Han Beiping's The Story of the African Night Party Leader: "After shaking hands with us, he sat in a rocking chair." A study shows that the swing beat that people are most likely to fall asleep is basically the same as the heartbeat frequency, which is 67 times per minute. Based on this research achievement, a rocking bed was developed, which swayed from side to side with a range of 5 cm, gradually slowed down and finally stopped swinging automatically.

Baidu Encyclopedia: Chair