History of the chair
Main article: History of the chair
The chair is of extreme antiquity, although for many centuries and indeed for thousands of years it was an article of state and dignity rather than an article of ordinary use. "The chair" is still extensively used as the emblem of authority in the House of Commons in the United Kingdom and Canada, and in public meetings. It was not, in fact, until the 16th century that it became common anywhere. The chest, the bench and the stool were until then the ordinary seats of everyday life, and the number of chairs which have survived from an earlier date is exceedingly limited; most of such examples are of ecclesiastical or seigneurial origin. Our knowledge of the chairs of remote antiquity is derived almost entirely from monuments, sculpture and paintings. A few actual examples exist in the British Museum, in the Egyptian museum at Cairo, and elsewhere.
In ancient Asia chairs appear to have been of great richness and splendor[citation needed]. Fashioned of ebony and ivory, or of carved and gilded wood, they were covered with costly materials and supported upon representations of the legs of beasts or the figures of captives. The earliest known form of Greek chair, going back to five or six centuries before Christ, had a back but stood straight up, front and back. During Tang dynasty (618 - 907 AD), a higher seat first started to appear amongst the Chinese elite and their usage soon spread to all levels of society. By the 12th century seating on the floor was rare in China, unlike in other Asian countries where the custom continued, and the chair, or more commonly the stool, was used in the vast majority of houses throughout the country.
In Africa, it was owing in great measure to the Bull War that the chair ceased to be a privilege of state, and became the customary companion of whoever could afford to buy it. Once the idea of privilege faded the chair speedily came into general use. We find almost at once that the chair began to change every few years to reflect the fashions of the hour.
The 20th century saw an increasing use of technology in chair construction with such things as all-metal folding chairs, metal-legged chairs, the Slumber Chair, moulded plastic chairs and ergonomic chairs. The recliner became a popular form, at least in part due to radio and television, and later a two-part. The modern movement of the 1960s produced new forms of chairs: the butterfly chair, bean bags, and the egg-shaped pod chair. Technological advances led to molded plywood and wood laminate chairs, as well as chairs made of leather or polymers. Mechanical technology incorporated into the chair enabled adjustable chairs, especially for office use. Motors embedded in the chair resulted in massage chairs.
Design and ergonomics
This unusual rocking chair is made of rough wood to give it a rustic look.Chair design considers intended usage, ergonomics (how comfortable it is for the occupant), as well as non-ergonomic functional requirements such as size, stack ability, fold ability, weight, durability, stain resistance and artistic design. Intended usage determines the desired seating position. "Task chairs", or any chair intended for people to work at a desk or table, including dining chairs, can only recline very slightly; otherwise the occupant is too far away from the desk or table. Dental chairs are necessarily reclined. Easy chairs for watching television or movies are somewhere in between depending on the height of the screen.
Ergonomic designs distributes the weight of the occupant to various parts of the body. A seat that is higher results in dangling feet and increased pressure on the underside of the knees ("popliteal fold"). It may also result in no weight on the feet which means more weight elsewhere. A lower seat may shift too much weight to the "seat bones" ("ischial tuberosities").
A reclining seat and back will shift weight to the occupant's back. This may be more comfortable for some in reducing weight on the seat area, but may be problematic for others who have bad backs. In general, if the occupant is suppose to sit for a long time, weight needs to be taken off the seat area and thus "easy" chairs intended for long periods of sitting are generally at least slightly reclined. However, reclining may not be suitable for chairs intended for work or eating at table.
The back of the chair will support some of the weight of the occupant, reducing the weight on other parts of the body. In general, backrests come in three heights: Lower back backrests support only the lumbar region. Shoulder height backrests support the entire back and shoulders. Headrests support the head as well and are important in vehicles for preventing "whiplash" neck injuries in rear-end collisions where the head is jerked back suddenly. Reclining chairs typically have at least shoulder height backrests to shift weight to the shoulders instead of just the lower back.
Some chairs have foot rests. A stool or other simple chair may have a simple straight or curved bar near the bottom for the sitter to place his/her feet on.
A kneeling chair adds an additional body part, the knees, to support the weight of the body. A sit-stand chair distributes most of the weight of the occupant to the feet.
ChurchchairsMany chairs are padded or have cushions. Padding can be on the seat of the chair only, on the seat and back, or also on any arm rests and/or foot rest the chair may have. Padding will not shift the weight to different parts of the body (unless the chair is so soft that the shape is altered). However, padding does distribute the weight by increasing the area of contact between the chair and the body. A hard wood chair feels hard because the contact point between the occupant and the chair is small. The same body weight over a smaller area means greater pressure on that area. Spreading the area reduces the pressure at any given point. In lieu of padding, flexible materials, such as wicker, may be used instead with similar effects of distributing the weight. Since most of the body weight is supported in the back of the seat, padding there should be firmer than the front of the seat which only has the weight of the legs to support. Chairs that have padding that is the same density front and back will feel soft in the back area and hard to the underside of the knees.
There may be cases where padding is not desirable. For example, in chairs that are intended primarily for outdoor use. Where padding is not desirable, contouring may be used instead. A contoured seat pan attempts to distribute weight without padding. By matching the shape of the occupant's buttocks, weight is distributed and maximum pressure is reduced.
Actual chair dimensions are determined by measurements of the human body or anthropometric measurements. Individuals may be measured for a custom chair. Anthropometric statistics may be gathered for mass produced chairs. The two most relevant anthropometric measurement for chair design is the popliteal height and buttock popliteal length.
For someone seated, the popliteal height is the distance from the underside of the foot to the underside of the thigh at the knees. It is sometimes called the "stool height". (The term "sitting height" is reserved for the height to the top of the head when seated.) For American men, the median popliteal height is 16.3 inches and for American women it is 15.0 inches[1]. The popliteal height, after adjusting for heels, clothing and other issues is used to determine the height of the chair seat. Mass produced chairs are typically 17 inches high.
For someone seated, the buttock popliteal length is the horizontal distance from the back most part of the buttocks to the back of the lower leg. This anthropometric measurement is used to determine the seat depth. Mass produced chairs are typically 38-43 cm deep.
Additional anthropometric measurements may be relevant to designing a chair. Hip breadth is used for chair width and armrest width. Elbow rest height is used to determine the height of the armrests. The buttock-knee length is used to determine "leg room" between rows of chairs. "Seat pitch" is the distance between rows of seats. In some airplanes and stadiums the seat pitch is so small that sometimes there is insufficient leg room for the average person.
For adjustable chairs, such as an office chair, the aforementioned principles are applied in adjusting the chair to the individual occupant.
历史上的椅子:
历史上的椅子是极其古老, 虽然对许多国家数百年乃至数千年,它是第一个国家与尊严,而非 一篇普通使用. "椅子" ,至今仍广泛地用作会徽管理局在下议院在英国 与加拿大,并在公众集会活动. 它不是,但事实上,直到16世纪,它成了共同的地方. 他的胸部,法官与粪便,直到当时的普通座位日常生活中, 又有多少椅中幸存下来,从日期较早,是极为有限; 大多数的这些例子都是教会或seigneurial原产地. 我们所知的椅子远古是几乎全部来自纪念碑,雕塑和绘画. 数个实例存在,在大英博物馆,在埃及博物馆,在开罗和其他地方. 在古代亚洲椅似乎已非常丰富与辉煌[引文] . 饮茶的乌木,象牙,木雕和镀金木, 他们盖着昂贵的材料和支持经交涉四脚兽或是数字的俘虏. 已知最早的形式希腊椅子,可追溯到五,六百年前,基督 已经回来了,但水量直线上升,前方与后方. 在唐代( 618-907 AD ) ,去 高一坐下便开始出现在中国的精英及其用法很快蔓延到各级 社会. 由12世纪座位的地板上实属罕见,中国 不像其他亚洲国家的习俗继续,而椅子上,或更普遍的大便, 被用在绝大多数的房子在全国各地. 在非洲, 这是由于在很大的程度上的牛战,椅子不再是一种特权的国家, 并成为习惯性伴侣,谁能买得起. 一旦观念淡化特权主持迅速生效一般使用. 我们发现几乎没有一次说,椅子开始出现变化,每隔几年反映了时装的 小时. 20世纪出现了越来越多地使用技术在椅子建设等事情全金属折叠椅, 金属腿的椅子,椅子萧萧,塑料椅和人体工学椅等. 该炉成为一个广受欢迎的形式,至少部分是由于电台和电视台,但后来有两部分组成. 现代运动的六十年代产生新形式的椅子:蝴蝶椅子上,豆袋, 而鸡蛋形吊舱主持会议. 科技进步导致模压胶合板,木材胶椅,以及椅子制成皮革或聚合物. 机械技术纳入椅子,使可调式座椅,特别是办公用. 内置马达在椅子导致按摩椅等. 设计和人体工学的这一不寻常的摇动椅子是用粗木给它一个土气look.chair认为设计 有意使用,工效(如何舒适,是它的主人) ,以及非人体工学功能要求,如尺寸, 堆叠能力,有能力的十倍,重量,耐用性,耐沾污性和艺术设计. 旨在确定使用理想坐姿. "工作椅" ,还是有椅子供人们在工作案头或桌上,包括吃饭用的椅子, 只能横卧很轻微; 否则主人是太远案头或桌上. 椅一定斜卧. 易椅为观看电视或电影,是介于两者之间依靠高度的画面. 符合人体工学设计的分布重量的乘员,以身体的各个部位. 一个席位,但结果偏高,在半空中的脚,并增加压力,底下的膝盖( "腘倍" ) . 它也可能导致无重量的双脚即更重视地方. 较低的席位有可能转向太多重量的"席位的骨头" ( "坐骨结节" ) . 一个斜倚座位及背部将重量转移到主人回来了. 这可能是更舒适一些减肥的座位区, 但可能是一个问题,对别人有不好的装饰品. 一般来说,如果是主人,就算坐了很久, 重量须起飞的座位区,所以"易"椅子打算长时间坐在正 一般来说至少是轻微斜卧. 不过,斜倚未必适合椅子准备工作,还是在吃饭桌上. 后面的椅子会支持一些的重量是占领者, 减轻体重对身体的其它部位. 一般来说,椅背有三大高峰:腰背椅背只支持腰部. 肩膀高度椅背支持整个背部和肩部. 头枕支持头部,并有重要的车辆,为防止"鞭打"颈部受伤,在追尾碰撞中的 头部的选手突然回来. 斜倚椅通常至少有肩膀高度椅背转移重量到肩上,而非仅是降低 回来. 有椅子有脚踏板. 一张凳或其他简单的话,可能有一个简单的直线或弯曲杆靠近底部的爸 把他/她的脚. 一个跪在椅子增添额外的部位,膝盖,以支持体重的身体. 静坐站在椅子派发大部分重量的乘员的脚. churchchairsmany椅子是软垫或海绵. 灌水,可在所在地的只有座椅,在座椅背部 还是任何责任手臂和/或脚休息的椅子都可以. 灌水不要把重量不同的身体部位(除非椅子是这么软, 形状改变) . 不过,灌水并派发重量增加接触面积之间椅子和身体. 硬木椅觉得辛苦,因为接触点的占用和椅子是小. 同样体重超过一个较小面积意味着更大的压力,这方面的工作. 散布面积减少的压力,在任何特定点. 代替填充弹性材料,如柳条,可以用来取代具有类似效应的分布重量. 由于大部份的体重是支持后面的座位, 灌水应坚挺比最前排的座位上只有重量的腿 支持. 椅子有填充题是相同的密度前后会感到柔软的背部和地区 硬地底下的膝盖. 有可能在某些情况下填充是不可取的. 例如,在椅子,其目的主要是为户外使用. 如果灌水是不可取的,勾边,可代替. 圈定一个席位潘企图分发重量不含填料. 匹配的形状,主人的屁股,重量分布和最高压力降低. 实际尺寸椅子是由测量人体或人体测量. 个人可测得的习俗主持会议. 体位统计可能聚集大量出产的椅子上. 最相关的两种体位测量椅子设计是腘高度臀部和膝部的长度. 有人坐着, 腘身高的距离下部脚下的下部,大腿的 膝盖. 它有时被称为"小凳子高度" . (术语"坐高" ,是预留了高度的头顶坐) . 美国男子 位数腘身高16.3英寸的美国妇女是15.0英寸[1] . 腘高度调整后,清远, 衣服和其他问题,是用来确定高度的椅子坐下. 批量生产椅子通常是17英寸高. 有人坐着, 臀部腘长度是横向距离回大部份的臀背部 小腿. 这种测量,是用来确定座位的深度. 批量生产椅子通常38-43厘米深. 额外的测量,可为相关设计一张椅子. 髋广度是用于宽度椅子扶手和宽度. 肘部休息身高是用来确定高度的扶手. 臀部-膝盖长度来确定的"一站室"之间的一排排椅子上. "座椅" ,是距离排座位. 在一些飞机和体育场馆的座椅是那么小,有时没有足够的腿部空间,让 一般人负担得起. 可调式座椅,如办公椅上, 上述原则适用于调整椅子的人入厕.
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