Description TAILOR-MADE CHAIR

Technical Field

[1] The present invention relates to a tailor made chair, and more particularly, a tailor made chair comprising a seat part, a back rest part, and a cervix supporting part, of which the length of seat, lower part of back rest, and upper part of back rest, and the width of cervix supporting part form a prescribed ratio against the length from the bottom side of seat part to the upper end of back rest part, so that the chair provides comfort and stability to its user in accordance with his/her body shape and allows the height of back rest part to be controlled. Background Art

[2] Generally, a disk is a kind of joint which has a disk shape and is located between spinal columns from cervical to lumbar vertebrae. Above and under the disk, there are cartilages contacted to the vertebrate bone, its round shaped margin is surrounded with multiple layers of elastic fibers, and a soft nucleus pulposus is contained in the central part inside the disk. The soft nucleus pulposus is a region to play a key role of disk and corresponds to an air contained tube when the loop fibers are compared to the rubber wheel of vehicle tire. The nucleus pulposus mostly comprises viscous proteins, contains much moisture, and plays roles as a cushion to absorb the impacts on the vertebrae and also as a joint to make the motion of spinal column be freely.

[3]

[4] From the measurements of the load by weight on the lumbar disk depending on changes of body posture, it was resulted that: when a user was lying down on his back, the smallest load as much as 1/3 of his body weight was pressured when lying down on his side, the similar load to of his body weight was pressured; when standing up, the impact as much as about 1.5 times of his body weight was pressured; and when sitting on a chair without leaning against the chair, the greatest impact as much as about 2 times of his body weight was pressured on his lumbar disks.

[5]

[6] In this context, there have been an issued patent of No. 435846 by this assignee.

[7] FIG. 1 is a perspective view displaying an existing spine corrective chair, and we would explain the existing invention of the issued patent No. 435846 with reference to FIG. 1. With reference to FIG. 1, the existing chair(lθ) comprises: a seat(20); and a back rest(30) formed in a united body with the seat(20), which is formed to a curved shape same to the curved line of the spinal column and has a projection(31) established in vertical direction to be contacted with the isthmus of user's back. In addition, hook

parts(33) are projected horizontally forward from the back rest(30). And on the upper part of the back rest part(30), a cervix supporting part(40) is established to support in covering the cervix rear side of user so as to distribute the load on the spinal column. Wherein, the hook parts(33) include height adjustable cushions to support the armpits of user. And legs(50) are linked mechanically to the lower part of the seat(20), support the seat(20) and the back rest(30), and have a structure to prevent the chair from falling down when a user is rested on it.

[8]

[9] Hereby, the existing chair can support the back isthmus of user and distribute the load on the lumbar disk through a composition to support user's body by suspending his armpits. However, because every user has different body shapes, it is necessary to modify the structure of seat or back rest according to the body shape of user to provide a chair appropriate to the body shape of each user. But the existing chair has not been able to provide enough stability to each user because of the fixed structure of seat or back rest.

[10]

[11] More specifically, in case that tall user uses the existing chair, as the length of seat is shorter relatively, the stability of user's hip is declined, the projection on the back rest part may not support fully the isthmus of user's back, the cervix supporting part does not reaching the cervix of the user, so that the user can not be rested on the chair comfortably.

[12]

[13] To the contrary, in case that short user uses the existing chair, as the length of seat is longer relatively, the stability of user's hip is declined, the projection on the back rest part may not support fully the isthmus of user's back, the cervix supporting part may be formed higher than the cervix of the user, so that the user can not be rested on the chair comfortably.

[14]

[15] Herein, the tall user is assumed to have a long sitting height and long legs, and the short user is assumed to have a short sitting height and short legs.

[16]

[17] To provide a chair appropriate to each use, we would seek for the interactive relation between the body sizes depending on the heights of users. Disclosure of Invention Technical Problem

[18] The present invention relates to a tailor made chair, and more particularly, a tailor made chair comprising a seat part, a back rest part, and a cervix supporting part, of

which the length of seat, lower part of back rest, and upper part of back rest, and the width of cervix supporting part form a prescribed ratio against the length from the bottom side of seat part to the upper end of back rest part, so that the chair provides comfort and stability to its user in accordance with his/her body shape and allows the height of back rest part to be controlled.

[19]

[20] Generally, a disk is a kind of joint which has a disk shape and is located between spinal columns from cervical to lumbar vertebrae. Above and under the disk, there are cartilages contacted to the vertebrate bone, its round shaped margin is surrounded with multiple layers of elastic fibers, and a soft nucleus pulposus is contained in the central part inside the disk. The soft nucleus pulposus is a region to play a key role of disk and corresponds to an air contained tube when the loop fibers are compared to the rubber wheel of vehicle tire. The nucleus pulposus mostly comprises viscous proteins, contains much moisture, and plays roles as a cushion to absorb the impacts on the vertebrae and also as a joint to make the motion of spinal column be freely.

[21]

[22] From the measurements of the load by weight on the lumbar disk depending on changes of body posture, it was resulted that: when a user was lying down on his back, the smallest load as much as 1/3 of his body weight was pressured when lying down on his side, the similar load to of his body weight was pressured; when standing up, the impact as much as about 1.5 times of his body weight was pressured; and when sitting on a chair without leaning against the chair, the greatest impact as much as about 2 times of his body weight was pressured on his lumbar disks.

[23]

[24] In this context, there have been an issued patent of No. 435846 by this assignee.

[25] FIG. 1 is a perspective view displaying an existing spine corrective chair, and we would explain the existing invention of the issued patent No. 435846 with reference to FIG. 1. With reference to FIG. 1, the existing chair(lθ) comprises: a seat(20); and a back rest(30) formed in a united body with the seat(20), which is formed to a curved shape same to the curved line of the spinal column and has a projection(31) established in vertical direction to be contacted with the isthmus of user's back. In addition, hook parts(33) are projected horizontally forward from.

[26]

[27] The present invention is to meet the need of user and solve the problems in association with chair, and it is suggested that a certain ratio is formed between the body sizes of user according to the height of user. Hereby, the present invention is provided to classify the grades according to the height of user and to suggest a standardized ratio of compartments of chair.

[28] In addition to the standardized ratio of compartments of chair, it is provided to give a convenience in use by controlling the height of back rest according to the individual physical conditions of each user.

[29] The present invention is to provide the length of seat part appropriate to the body shape of user according to the prescribed ratio of chair compartments.

[30] The present invention is to provide the width of the lower part of back rest appropriate to the body shape of user according to the prescribed ratio of chair compartments.

[31] The present invention is to provide the width of the upper part of back rest appropriate to the body shape of user according to the prescribed ratio of chair compartments.

[32] The present invention is to provide the width of the cervix supporting part appropriate to the body shape of user according to the prescribed ratio of chair compartments.

[33] The present invention is to provide a composition of back rest to support fully the back isthmus of user through the projection formed on the back rest.

[34] In addition, the present invention is provided to allow each user to get comfort and stability through the standardized chair and to make the waist of user comfortable by distributing the load on the spinal column. Technical Solution

[35] The object of present invention is accomplished by providing a tailor made chair including: a seat part where user's hip is rested; a back rest part, which is combined with the rear end of the seat part, has a shape same to that of user's back so as to support the user's back, and includes wing part on both side of it so as to cover partially user's back; and a cervix supporting part, which has a shape same to that of user's cervical rear side and includes wing part on both side of it so as to cover partially user's cervical rear side, and having the length of major parts in the seat part, back rest part, and cervical supporting part, the height(a), hip length(b), waist width(c), shoulder width(d), and head width, which are satisfied with a ratio of a: b: c: d: e = 1 : 0.681-0.729 : 0.492-0.527 : 0.667-0.744 : 0.264-0.296.

[36]

[37] Wherein in the case that the height of user is not less than 150cm and not more than

160.5cm, the height(a) is formed to not less than 58.5cm and not more than 59.5cm, the hip length(b) to not less than 42.5cm and not more than 43.5cm, the waist width(c) to not less than 28.5cm and not more than 29.5cm, the shoulder width(d) to not less than 39.5cm and not more than 40.5cm, and the head width(e) to not less than 15.5cm and not more than 16.5cm.

[38]

[39] Wherein in the case that the height of user is not less than 160.5cm and not more than 165.5cm, the height(a) is formed to not less than 61.5cm and not more than 62.5cm, the hip length(b) to not less than 44.5cm and not more than 45.5cm, the waist width(c) to not less than 30.5cm and not more than 31.5cm, the shoulder width(d) to not less than 42.5cm and not more than 43.5cm, and the head width(e) to not less than 16.5cm and not more than 17.5cm.

[40]

[41] Wherein in the case that the height of user is not less than 165.5cm and not more than 170.5cm, the height(a) is formed to not less than 64cm and not more than 65cm, the hip length(b) to not less than 45.5cm and not more than 46.5cm, the waist width(c) to not less than 33.5cm and not more than 34.5cm, the shoulder width(d) to not less than 47.5cm and not more than 48.5cm, and the head width(e) to not less than 18.5cm and not more than 19.5cm.

[42]

[43] Wherein in the case that the height of user is not less than 170.5cm and not more than 175.5cm, the height(a) is formed to not less than 66.5cm and not more than 67.5cm, the hip length(b) to not less than 46.5cm and not more than 47.5cm, the waist width(c) to not less than 34.5cm and not more than 35.5cm, the shoulder width(d) to not less than 47.5cm and not more than 48.5cm, and the head width(e) to not less than 18.5cm and not more than 19.5cm.

[44]

[45] Wherein in the case that the height of user is not less than 175.5cm and not more than 180.5cm, the height(a) is formed to not less than 69cm and not more than 70cm, the hip length(b) to not less than 47.5cm and not more than 48.5cm, the waist width(c) to not less than 35.5cm and not more than 36.5cm, the shoulder width(d) to not less than 47.5cm and not more than 48.5cm, and the head width(e) to not less than 18.5cm and not more than 19.5cm.

[46]

[47] Wherein in the case that the height of user is not less than 180.5cm and not more than 190cm, the height(a) is formed to not less than 71.5cm and not more than 72.5cm, the hip length(b) to not less than 47.5cm and not more than 48.5cm, the waist width(c) to not less than 36.5cm and not more than 37.5cm, the shoulder width(d) to not less than 47.5cm and not more than 48.5cm, and the head width(e) to not less than 18.5cm and not more than 19.5cm.

[48]

[49] Wherein the said back rest seat have additional projection in vertical direction on the location where user's isthmus is contacted in the central part of its inner surface.

[50]

[51] Wherein said back rest seat has hook parts additionally which are projected forward so as to support the armpits of user through hooking. [52] [53] Wherein said cervical supporting part has a belt additionally which covers the external side of it and makes a user be rested on the back rest in a state of covering shoulders and armpits of user. [54] [55] wherein a supporting part is formed on the rear end of said seat part so as to cover the hip of user partially, and said seat part and said back rest part are combined each other by a height controlling member to control the height of the back rest part. [56] [57] Wherein said height controlling member is established on the lower part of the seat part, on the rear side of a height controlling frame with a guiding hole and the back rest part.

Advantageous Effects

[58] Thus, the tailor made chair of the present invention has effects: to facilitate for each user to select appropriate chair by providing chairs classified into standardized grades depending on the height of user; to allow the manufacturing process of the chair giving comfort and stability to user to be simplified by supplying a prescribed ratio formed among the height(a), the hip width(b), the waist width(c), the shoulder width(d), and the head width; to provide comfort and stability to user through the chair having the above mentioned structure to make user's waist comfort by dispersing the load on user's vertebrae and to provide convenience in use by controlling the height of back rest depending on the use's characteristics. Brief Description of the Drawings

[59] The foregoing and other features and advantages of the present invention will be more readily appreciated as the same become better understood from the following description when taken in conjunction with the accompanying drawings, wherein:

[60] FIG. 1 is a perspective view displaying an existing spine corrective chair;

[61] FIG. 2 is a perspective view displaying a chair according to an embodiment of the present invention

[62] FIG. 3 is a magnified perspective view displaying an embodiment of "A" part of

FIG. 2;

[63] FIG. 4 is a magnified perspective view displaying another embodiment of "A" part of FIG. 2;

[64] FIG. 5 is a disassembled perspective view of a height controlling member applied to

an embodiment of the present invention;

[65] FIG. 6 is a side view of the back rest part with the lowest height according to an embodiment of the present invention;

[66] FIG. 7 is a side view of the back rest part with the highest height according to an embodiment of the present invention;

[67] FIG. 8 is a perspective view of the essential parts displaying a chair according to an embodiment of the present invention. Best Mode for Carrying Out the Invention

[68] While preferred embodiments of the present invention have been shown and described with a degree of particularity with reference to the drawings, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

[69] FIG. 2 is a perspective view displaying a chair according to an embodiment of the present invention. With reference of FIG. 2, a chair(lOO) is compartmentalized into legs (140), a seat part(l 10), and a back rest part(120). The legs(140) are linked to the lower part of the seat part(l 10) mechanically, the height of legs is controlled between the seat part(l 10) and ground by a vertical frame(141), the seat part(l 10) and the back rest part(120) established on the upper part of the legs are supported and the chair(lOO) is prevented from falling down when a user seats himself on it by a horizontal frame(143).

[70]

[71] Under marginal part of the horizontal frame(143), wheels(145) are established so as to facilitate moving of the chair(lOO).

[72]

[73] The legs(140) are satisfied with being established on the lower part of the seat part(lOO), supporting the seat part(l 10) and the back rest part(120), and preventing the chair(lOO) from falling down when a user seats himself on it, and the structure of the legs (140) are not limited herein and it may readily be effected by persons skilled within the art. The seat part(l 10) is linked to the legs(140) mechanically through its lower part, and the hip is rested on its upper part.

[74]

[75] On the rear end of the seat part(l 10), a supporting part (111) may be formed to cover partially as like supporting the rested hip of user and give comfort and stability to the user.

[76]

[77] The back rest part(120) is parted and established with the seat part(l 10), and is formed to a shape same to the back of user so as to support that. Through elongation of

both lateral margin of the back rest part, a wing part(123) to cover both sides of user may be formed additionally. Especially, on the lower part of the back rest part(120), the wing part(123) covers comfortably the side of user, gives comfort to the waist, and makes the body be erect by dispersing the load on the waist. The wing part(123) is formed with projecting about 5cm ~ 10cm forward the chair(lOO). The length of the wing part(123) may be changed by the seated user and not be limited in the present invention.

[78]

[79] And the separated seat part(l 10) and back rest part(120) are combined each other through a height controlling member(130) to be mentioned later. Wherein, on the central part of the inner surface of back rest part(120), projections are formed additionally in vertical direction on the location where user's isthmus is contacted, a cervix supporting part(125) to have a shape same to that of the rear side of user so as to support the rear side of cervix of the seated user is formed on the upper part of the back rest part( 120).

[80]

[81] The cervix supporting part(125) has a supporting part(125a) form on both side of that, and supports the rear side of cervix of user through wrapping, so that the rear head of user is rested on the cervix supporting part(125). Although not shown in figures, it is advantageous that the cervix supporting part(125) is manufactured separately with the back rest part(120), assembled through a combining implement, and established to allow its height to be controlled on the back rest part(120).

[82]

[83] Although not shown in figures, an armrest to support the arms of user may be established on the seat part(l 10). Wherein the structure of said armrest which may readily been modified by persons skilled within the art, is omitted.

[84]

[85] Besides, an existing hook parts may be established on the back rest part(120) so as to support the armpits of user.

[86]

[87] Wherein instead of the existing hook parts, it is advantageous that a belt(150) is formed to cover the armpits of user with covering the cervix supporting part(125). The belt(150) should be manufactured enough long to fix the shoulders and armpits of user with covering them. Thus, the belt(150) make user be rested on the chair(lOO) in a state of covering the shoulders and armpits of user and the weigh load of user may be dispersed to the seat part(l 10) and the back rest part(120).

[88]

[89] FIG. 3 is a magnified perspective view displaying an embodiment of "A" part of

FIG. 2 and FIG. 4 is a magnified perspective view displaying another embodiment of "A" part of FIG. 2.

[90]

[91] Shown in FIG. 3, a Velcro may be attached to facilitate the attaching and removing of the belt(150) on the belt(150). In addition, shown in FIG. 4, a clip(153) may be established on the belt(150) to rest the shoulders and armpits of user on the chair. In other words, the belt(150) to cover the shoulders and armpits of user is inserted into the clip in crossed manner and is fastened by pulling the end part of the belt(150).

[92]

[93] As a tightening and releasing method of said belt(150), there are many methods other than Velcro(151) and clip(153). For example, a buckle, a press button, or a snap faster may be used as a tightening and releasing method of said belt(150). The belt(150) is satisfied with allowing the user to be rested on the chair(lOO) by covering the shoulders and the armpits of user, and the tightening and releasing method of said belt(150) is not limited herein and it may readily be modified by persons skilled within the art.

[94]

[95] FIG. 5 is a disassembled perspective view of a height controlling member applied to an embodiment of the present invention. With reference of FIG. 5, the height controlling member(130) comprises a height controlling frame(131) established on the lower part of seat part(l 10) and a frame housing(135) established on the rear side of back rest part(120). Wherein the height controlling frame(131) guiding has a perforating hole and the frame housing(135) has a screw holes(137), so that the height controlling frame(131) is inserted into the frame housing(135) and the seat part(l 10) and the back rest part(120) are combined by a fixing screw(139) which perforates the screw hole(133) and the guiding hole(135).

[96]

[97] FIG. 6 is a side view of the back rest part with the lowest height according to an embodiment of the present invention, and FIG. 7 is a side view of the back rest part with the highest height according to an embodiment of the present invention. With reference to FIG. 6 and FIG. 7, the height of back rest part(120) is controlled along the guiding hole by unfastening of the fixing screw(139) and fixed by fastening of the fixing screw(139) so as to combine the seat part(l 10) and the back rest part(120).

[98]

[99] In other words, as shown in FIG. 6, the height controlling frame(131) and the frame housing(135) are fixed by fastening of the fixation screw and the back rest part(120) are coupled with the seat part(l 10) at the lowest height. Then, by unfastening the fixation screw(139), the height of back rest part(120) may be controlled through

moving the screw along the guiding hole(139) and the fixation and coupling of the height controlling frame(131) and the frame housing(135) is accomplished by fastening the fixation screw(139). Thus, the back rest part(120) is coupled with the seat part(l 10) at the highest height as shown in FIG. 7.

[100]

[101] The above mentioned height controlling member(130) is only an embodiment to explain the method for controlling height of the back rest part(120) and not limited herein, and it may readily be modified by using the published other method. Therefore, the chair(lOO) according to an embodiment of the present invention may allow the distorted waist of user to be erect and prevent distortion of the waist in advance.

[102]

[103] FIG. 8 is a perspective view of the essential parts displaying a chair according to an embodiment of the present invention. With reference to FIG. 8, the seat part(l 10) is formed to a shape same to the rested hip part of user so as to rest the hip of user and the back rest part(120) is formed to a shape same to the back part of user so as to rest the back of user.

[104]

[105] The cervical supporting part(125) is extended upward from the upper part of the back rest part, so as to support the rear part of user's neck by covering it.

[106] The seat part(l 10) and the back rest part(120) shown in this FIG. 8are coupled within one body, as what is mentioned above it may be allowed that the seat part(l 10) and the back rest part(120) are formed in the state of being separated and are coupled via the height controlling member(130). And the coupling structure of the seat part(l 10) and the back rest part(120) is omitted.

[107] This inventor confirmed in the present invention that from recognizing the point that the figures of body size are varied according to the height of individual users, in case that the length from the upper part of seat part(l 10) formed when an user is rested on the chair to the upper end of back rest part(120)(a), the length from the rear end to the front end of seat part(l 10)(b), the width of the lower part of back rest part(120), the width of the upper part of back rest part(120), and the width of cervical supporting part(125)(e) are formed at a prescribed ratios corresponding to the figures of body size, the user can be rested on the chair with the most stable and comfortable posture, and would explain in more detail.

[108]

[109] Herein, the length from the upper part of seat part(l 10) to the upper end of back rest part(120) is referred to the height(a), the length from the rear end to the front end of seat part(l 10) to the hip length (b), the width of the lower part of back rest part(120) to the waist width(c), the width of the upper part of back rest part(120) to the shoulder

width(d), and the width of cervical supporting part(125) to the head width(e).

[HO] [111] [Experiment 1] [112] The experiments in this present invention are conducted on the 50 subjects with height not less than 150cm and not more than 190cm. And we manufactured chairs in accordance with the body size of each subject and measured the size of each part of the chair(initial chair).

[113] [114] Herein, each manufactured chair (initial chair) was manufactured in accordance with the body shape of each subject, and the subject might take a most comfortable and stable posture when he/she was rested on it.

[115] [116] In addition, the measured values of the height(a), the hip length (b), the waist width(c) the shoulder width (d), and the head width (e) described in experiments hereafter were the length of points shown in FIG. 8, and the values were measured when each subject takes the most comfortable and stable posture from being rested on the chair.

[117] [118] As a result, the range of measured values corresponding to the height(a), the hip length(b), the waist width(c) the shoulder width(d), and the head width(e) were figured out.

[119] [120] Following table 1 shows the range of measured values by each parts(a, b, c, d, and e) of the chair(initial chair)

[121] [122] Table 1

[123] [124] The values expressed in the table 1 were figured out through rounding up and the unit of value was cm.

[125]

[126] [Experiment 2] [127] With reference to the measured values of initial chair for each subject for figuring out the values of table 1 and the values in table 1, the subjects were classified multiple experimental groups by their heights and the mean values for the measured values of each part(a. b. c. d. e) were calculated according to the classified heights.

[128] [129] Concurrently, the average chairs manufactured according to the above calculated mean value were provided to each experimental group for each subject to be rested on them for 1 hour. Then each subject were given with a stability check table having 5 standard levels and completed the standard stability check table comparing with the initial chair.

[130] [131] Table 2

[132] [133] The above table 2 is a standard stability check table classified to 5 degrees. [134] [135] Through this check table, this inventor judged that the subject could be taken comfort and stability from the chair in case that the satisfaction degree was above normal.

[136] In other words, it was considered that in case that the satisfaction degree was above normal, the subject could be taken comfort and stability same to the initial chair from the average chair.

[137] [138] The measuring by using this check table resulted in classification table as shown in table 3.

[139] [140] Table 3

[141] [142] Table 3 is a classification table displaying the highest satisfaction degree among multiple tables classified according to the height of subject.

[143] The unit of value in table 3 was cm. [144] The values of check table completed by the classification table of table 3 were arranged like table 4.

[145] [146] Table 4

[147] [148] Table 4 is a table representing the satisfaction degrees for the classification table corresponding to table 3. In this table, the satisfaction degrees for the classification table corresponding to table 3 appears 86%

[149] [150] [Experiment 3] [151] To valuate the error range for the values expressed in the classification table of table 3 subjected on the subjects corresponding to the satisfaction degree of 86%, each value of the height(a), the hip length(b), the waist width(c), the shoulder width(d), and head width(e) was modified respectively and then the subjects completed the check table of table 2 again.

[152] [153] Table 5

Error range from the values of classification table(cm)

-1.5 -1 -0.5 0 0.5 1.5

[154] [155] Table 5 is an error distribution table of the shoulder width, which is outlined based on the check table completed in the experiment 3.

[156] [157] With reference to the table 5, in case that the shoulder width was increased or reduced as much as 0.5cm from the value in classification table, while there were some changes in satisfaction degree, it was shown that the subjects were still being taken enough comfort and stability for the chair used in the experiment.

[158] [159] And 37 subjects, 86% of subjects in the experiment, answered that they got the stability same to the initial chair in the values of classification table having 0 value as errors.

[160] [161] However, in case that the error range of the shoulder width(d) exceeds not less than -0.5cm and not more than 0.5cm as shown in table 5, the results were expressed to have no stability on the upper part of back rest part(120). In other words, the shoulder width(d) can be altered within the error range between -0.5cm and 0.5cm.

[162] [163] Besides, as the similar results of table 5 were displayed in other measuring points, the tables representing the error ranges about the height(a), the hip length (b), the waist width(c), and head width (e) were omitted.

[164] [165] While not shown in the table, in case that the error range of the height(a), the hip length(b), the waist width(c), and head width(e) exceed not less than -0.5cm and not more than 0.5cm, the results were expressed to have no stability on the upper part of back rest part(120). In conclusion, the result values of the classification table shown in table 3 might be changed out of error range from -0.5cm to 0.5cm.

[166] [167] [Experiment 4] [168] For 2 subjects displayed on the satisfaction degree from the result of experiment 2, the initial chair, and the average chair were analyzed for comparison.

[169] [170] The 2 subject resulting in unsatisfied degree displayed instability about the hip length(b) and the waist width(c) respectively.

[171] [172] Herein, the above 2 subjects had the highest or the lowest measured value for the initial chair among the same experimental group to the classification value. In addition, 4 of 5 subjects answering very unsatisfied degree could bring some stability of other parts by controlling the height(a).

[173] [174] [Experiment 5] [175] To identity the interactive relation to the measured parts about the classification table of table 3, the mean values of each parts were divided by the mean value.

[176] [177] Table 6

[178] [179] Table 6 displays the ratio of each part against the height(a). In table 3 and table 6,the height of subjects in experimental groups was expressed by rounding up. With reference to table 6, it was suggested that the hip length(b), the waist length(c), the shoulder width (d), and the head width (e) had a certain range of ratio based on the height(a).

[180] [181] In other words, the ratio of height(a), the hip length(b), the waist length(c), the shoulder width (d), and the head width (e) can be derived as follows:

[182] a: b: c: d: e = 1 : 0.681-0.729 : 0.492-0.527 : 0.667-0.744 : 0.264-0.296. [183] [184] A chair manufactured by using the above ratio range can give a comfort and stability to its user when he/she is rested on it. Industrial Applicability

[185] Since modifications within the spirit and scope of the invention may readily be effected by persons skilled within the art, it is to be understood that this invention is not limited to the particular embodiment described by way of example hereinabove.

[186] While preferred embodiments of the present invention have been shown and described with a degree of particularity with reference to the drawings, it should be understood that various modifications and changes could be made without departing from the spirit and scope of the invention.