WO2002056734A1

WO2002056734A1 - Shampoo chair

Info

Publication number: WO2002056734A1
Application number: PCT/KR2002/000070
Authority: WO
Inventors: Byung-Chul Lee
Original assignee: Byung-Chul Lee
Priority date: 2001-01-16
Filing date: 2002-01-16
Publication date: 2002-07-25
Also published as: KR20020061331A; KR100416243B1

Abstract

Disclosed herein is a shampoo chair having a seat (10) and a backrest (20). The shampoo chair further includes a neck rest (31) and two rotating members (32). Each of the rotating members (32) connects the neck rest (31) to the backrest (20), and is connected to the neck rest (31) and/or the backrest (20) in a ball joint fashion. To this end, both ends of the rotating member (32) are spherically shaped. The neck rest (31) is provided with two holding socket portions each having a holding socket for rotatably holding one sperically shaped end of the rotating member (32), and the backrest (20) is provided with two holding socket portions each having a holding socket for rotatably holding one spherically shaped end of the rotating member (32). Accordingly, users, who wash their hair, can utilize the shampoo chair conveniently and comfortably regardless of physical differences among them.

Description

SHAMPOO CHAIR

Technical Field

The present invention relates generally to a chair, and more particularly to a shampoo chair that is utilized to wash human hair.

Background Art

In general, human hair is washed at a barber or beauty shop after being cut or dressed. To this end, a person should droop his head toward a sink while sitting on a chair, or lean his head backwards to a sink while resting against the backrest of a chair. Fig. 16 shows a conventional chair and a conventional sink for a barber/beauty shop.

Referring to Fig. 16, a chair 100 provided with a backrest 110, and a sink

200 provided separately from the chair 100 and situated near the backrest 110 are illustrated.

The backrest 110 is slanted to the sink 200 at a certain angle and fixedly attached to the chair 100 so that a user has his hair washed while comfortably resting against the backrest 110.

The sink 200 is provided with a neck rest 210 that is concavely formed near the backrest 110 to support the cervical region (or the neck) of the user while sitting on the chair 100. When the user has his hair washed using the chair 100 and the sink 200, the neck of the user is brought into contact with the sink 200, thereby causing a discomfort to the user. Additionally, the height of the neck rest 210 of the sink 210 and the slant angle of the backrest 110 of the chair 100 are fixed to be constant, so the hair washing positions of some users may be made unstable and uncomfortable by their physical differences.

In addition, the conventional chair 100 and the conventional sink 200 occupy relatively large spaces and are relatively expensive, so they are installed only at a business area, such as a barber or beauty shop, for performing shampooing, but have limitations that they cannot be used at home as convenient and inexpensive chairs. ^•

Accordingly, at home, infants and the old and weak should have their hair washed while sitting on general chairs or being held in a person's arms, which inconveniences both a washing person and a washed person.

Disclosure of the Invention

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a shampoo chair, which is capable of keeping the neck portion of a washed person from being brought into contact with a sink and controlling a distance between a neck rest and a backrest in consideration of the physical differences among washed persons. Another object of the present invention is to provide a shampoo chair, which is capable of being easily and conveniently utilized for infants or the weak or old at home or in hospitals.

In order to accomplish the above object, the present invention provides a shampoo chair having a seat and a backrest, comprising a neck support means attached to the backrest for freely supporting the neck of a user in a random position.

Preferably, the neck support means may includes a neck rest and one or more rotating members connecting the neck rest and the backrest to allow a position of the neck rest to be changed.

Preferably, the rotating members, the neck rest and/or the backrest may be connected to each other in a ball joint fashion.

Preferably, the rotating members may be provided at their one-side ends with first spherical ends and at their other-ends with second spherical ends, the neck rest may be provided with a first holding socket block having first holding sockets in which the first spherical ends of the rotating members are rotatably supported, and the backrest may be provided with a second holding socket block having second holding sockets in which the second spherical ends of the rotating members are rotatably supported.

Preferably, the rotating members may further include projections formed between the first and second spherical ends to restrict rotation of the neck rest to a certain range.

Preferably, the first and/or second holding sockets may be formed by rings and friction members having a large friction coefficient in comparison with that of the rings.

Preferably, the second spherical ends may be each provided with at least one groove along a direction of rotation, and the second holding socket blocks are each provided with a rotation shaft and a manipulation lever rotated around the rotation shaft and designed to allow its one end to be inserted into or removed from the groove and its other end to be manipulated from the outside. Preferably, the rotating members may each include a first rod whose one end is fastened to the neck rest and whose other end constitutes a third spherical end, a second rod whose one end is fastened to the neck rest and whose other end constitutes a fourth spherical end, and a third holding socket block provided with a third holding socket for rotatably holding the third spherical end of the first rod and a fourth holding socket for rotatably holding the fourth spherical end of the second rod, thereby connecting the first and second rods.

Preferably, the rotating members may be pliable rods whose one-side ends are fastened to the neck rest and whose other-side ends are fastened to the backrest. In this case, the pliable rods are coated with high polymer resin. Preferably, the rotating members may be flexible tubes whose one-side ends are fastened to the neck rest and whose other-side ends are fastened to the backrest.

Preferably, the shampoo chair may further include a height adjusting means attached to the backrest to support the rotating members and adjust their height. Preferably, the neck rest comprises a neck rest cover provided with forwardly projected side ends, a rearwardly and roundly slanted rear portion, and one or more drain grooves, and a cushion contained in the neck rest cover.

Preferably, the shampoo chair may further include a backrest angle adjusting means mounted on an armrest for folding the backrest and the seat and controlling the slant angle of the backrest, an auxiliary leg rotatably mounted on a back surface of the backrest for supporting the backrest, an auxiliary seat mounted on a front surface of the backrest to be folded, support legs mounted on a bottom surface of the seat for supporting the seat and the backrest on the ground, and a support leg folding means for folding the support legs onto the bottom surface of the seat.

Brief Description of the Drawings

The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

Fig. 1 is a front perspective view showing a shampoo chair in accordance with an embodiment of the present invention;

Fig. 2 is a rear perspective view showing a backrest and a headrest removed from the shampoo chair of Fig. 1 with the cover of the backrest partially cut away;

Fig. 3 is a side sectional view showing the neck rest of Fig. 2 in use;

Fig. 4 is a side sectional view of the neck rest and a rotating member illustrating a rotation range of the neck rest;

Fig. 5 is an exploded perspective view showing an example of an auxiliary leg attaching means with an auxiliary leg removed from the backrest, which can be applied to the shampoo chair of the present invention;

Fig. 6 is a partial cutaway view showing an example of a backrest angle adjusting means that can be applied to the shampoo chair of the present

invention;

Fig. 7 is a perspective view showing an example of a support leg folding means that can be applied to the shampoo chair of the present invention; Figs. 8 to 15 are views showing modifications of a rotation member of the shampoo chair of the present invention; and

Fig. 16 shows a perspective view of a conventional chair and a conventional sink.

Best Mode for Carrying Out the Invention

Hereinafter, with reference to the accompanying drawings and embodiments, a shampoo chair in accordance with the present invention is described in detail.

Fig. 1 is a perspective view of a shampoo chair in accordance with an embodiment of the present invention. Fig. 2 is a view showing a backrest and a headrest removed from the shampoo chair of Fig. 1 with the cover of the backrest partially cut away. Fig. 3 is a side sectional view showing the neck rest of Fig.

2.

Referring to Figs. 1 and 2, the shampoo chair is comprised of a seat 10 on which a user can sit, a backrest 20 that supports the back of the user, and a neck support means 30 that is attached to the backrest 20.

Additionally, the shampoo chair further comprises two armrests 40 mounted on both sides of the seat 10, a backrest angle adjusting means 50 mounted on one of the armrests 40 to fold the seat 10 and the backrest 20 and adjust the slant angle of the backrest 20, an auxiliary leg 60 mounted on the backrest 20 to support the backrest 20 in a reclined state, an auxiliary seat 70 mounted on the front of the backrest 20 to be foldable, two support legs 80 mounted on the bottom of the seat 10 to support the seat 10 and the backrest 20 on a support surface, a support leg folding means for folding the support legs 60 and the seat 10, and a height adjusting means 134 designed such that its one end is connected to the neck support means 30 and its other end is retractable with its part inserted into the backrest 20. In order to allow the neck to be naturally and stably laid on the neck support means 30, the neck support means 30 is comprised of a neck rest 31 provided with two holding socket blocks 31c, two support members 33 combined with the backrest 20 and each provided with two holding socket blocks 33 a, and two rotating members 32 provided to connect the holding socket blocks 31c to the holding socket blocks 33a so as to change the position of the neck rest 31, respectively.

Referring to Fig. 3, the neck rest 31 is comprised of a cushion 31a made of soft and elastic material such as urethane foam, synthetic rubber or sponge, a neck rest cover 31b disposed around the cushion 31a and made of material that is waterproof and rustproof, such as plastic, and the holding socket blocks 31c attached to the bottom of the neck rest cover 3 lb. In this case, the holding socket blocks 31c are interlocked with the one-side ends of the rotating members 32.

Referring to Figs. 1 and 2, the front of the neck rest cover 31b is shaped to allow its two ends to protrude forward so as to surround the neck of a washed person, and the back of the neck rest cover 31b is downwardly curved to allow water sticking to the hair to flow into the sink 90 and provided with a plurality of drain grooves 31ba at its top surface. Referring to Fig. 3, in order to connect the neck rest 31 and the backrest

20 to be rotatable with respect to each other, ball-shaped, spherical ends 32a and 32b are formed at both ends of each rotating member 32, respectively, and holding sockets are formed in the holding socket blocks 31c and 33a, respectively. According to the above-described construction, the spherical ends 32a formed at the one-side ends of the rotating members 32 are inserted into the holding sockets of the holding socket blocks 31c of the neck rest 31 to be rotatable, and the spherical ends 32b formed at the other-side ends of the rotating members 32 are inserted into the holding sockets of the holding socket blocks 33 a, so the neck rest 31 can change its position within a certain rotation range as occasion demands. However, in order to prevent the head of a washed person from being easily moved and to allow the head to be stably placed on the neck rest 31, the spherical ends 32a and 32b are preferably interference-fitted into the holding sockets, so the spherical ends 32a and 32b are brought into contact with the holding socket blocks 31c and 33a to allow a large amount of surface factional force to be exerted therebetween.

Fig. 4 is a side sectional view of the neck rest and the rotating member illustrating a rotation range of the neck rest.

Referring to Fig. 4, when the user puts his head on the neck rest 31 or 31 ' and leans the neck rest 31 backwards while sitting on the seat 10, the neck rest 31 or 31' is rotated at an angle of α as shown by solid and dotted lines. Additionally, the rotating members 32 and 32' are rotated at an angle of β. Accordingly, the neck rest 31 can be moved in the range of angles α and β. Referring to Fig. 2, the height adjusting means 134 is a means for providing convenience to a user, and is comprised of two racks 33b respectively connected to the holding socket blocks 33a and provided with a plurality of horizontal teeth and two pinions 23 that can engage with the racks 33 b, respectively. In order to allow the racks 33b to be retracted from the backrest 20 while being kept in the backrest 20, two rack holes 20a are formed in the back portion of the backrest 20 to receive the racks 33 b, and the pinions 23 are rotatably attached to the back surface of the backrest 20 by a holding member 22 such as a socket holder. The holding member 22 holds the pinions 23 to be brought into tight contact with the racks 33b. The holding member 22 prevents the racks 33b from being moved by their own weight, so the racks 33b can be moved by a certain amount of external force caused by pushing or pulling.

Stopper projections 33c are formed at the lower ends of the racks 33b so as to prevent the pinions 23 from being removed from the racks 33b. Although the height adjusting means 134 is described as an example of a means for vertically moving the support members 33 by using the racks 33b and the pinions 23, the height adjusting means 134 is not limited to this example. The height adjusting means 134 can be comprised of a latchet mechanism. This construction will be apparent to those skilled in the art, so a detailed description of the construction is omitted. Additionally, although the support members 33 are described as being comprised of the holding socket blocks 33 a, racks 33b and the stopper steps 33c, this is an example of a part of the height adjusting means 134. Alternatively, support members provided with holding socket blocks 33a are directly connected to the backrests 20.

The auxiliary seat 70 allows the shampoo chair to be used for one- to four-year old infants that are short.

With a hinge 71 that can be folded at a right or certain angle with respect to the backrest 20, the backrest 20 and the auxiliary seat 70 can be combined with each other. In this case, it is desirable for the storing of the auxiliary seat 70 to provide the backrest 20 with an auxiliary seat storing depression 24 formed to place and store the auxiliary seat 70 and a locking projection 20b formed on one side of the auxiliary seat storing depression 20b.

The auxiliary leg 60 is used to allow an infant or the like to assume a comfortable position by tilting the backrest 20 rearwards when the hair of the infant or an old or weak person is washed without the use of the sink. In accordance with an example, the auxiliary leg 60 is comprised of a cylinder portion 62 projected to the right and left, an upper auxiliary leg portion 63 extended downwardly from the cylinder portion 62, a lower auxiliary leg portion 65 designed to be inserted into the upper auxiliary leg portion 63, a connecting pin 64 connecting the lower auxiliary leg portion 65 to the upper auxiliary leg portion 63, and a cylinder attaching means 61 for attaching the cylinder portion 62 to the back surface of the backrest 20.

In such a case, a bolt can be used to connect the lower auxiliary leg portion 65 to the upper auxiliary leg portion 63 in a screw fashion, instead of the connecting pin. A sliding-proof groove 65a is formed on the bottom surface of the lower auxiliary leg portion 65 to prevent the lower auxiliary leg portion 65 from sliding on a support surface such as the ground. An auxiliary leg receiving groove 20b is formed on the backrest 20 and the backrest cover 21 to accommodate the auxiliary leg 60 for the convenience of storing.

Fig. 5 is an exploded perspective view of an example of the cylinder attaching means 61 with the auxiliary leg 60 removed from the backrest 20.

Referring to Fig. 5, the cylinder attaching means 61 is comprised of a cylinder portion 62 provided at its center with a center hole 62b and around the center hole 62b with a plurality of holes 62a, two supports 61 each provided at its center with a center hole 61b and around the center hole 61b with a through hole 61a and fastened to the backrest with the cylinder portion interposed therebetween, a bolt 65 inserted into the center hole 62b of the cylinder portion 62 and the center holes 61b of the supports 61, a nut 66 combined with the bolt 65, and a stopper pin 67 to be inserted into the through hole 62a formed in the peripheral portion of the cylinder portion 62 and the through holes 61a formed in the peripheral portions of the supports 61.

With the construction of the cylinder attaching means 61, the auxiliary leg 60 can be attached to the backrest 20 with the cylinder portion 62 rotatable around the bolt 65, and the stopper pin 67 is selectively inserted into one of the plurality of through holes 62a formed in the peripheral portion of the cylinder portion 62 to adjust the rotation angle of the auxiliary leg 60. Accordingly, even though the ground is slippery, the auxiliary leg 60 effectively supports the backrest 20 at a certain angle and prevents the shampoo chair from being imbalanced.

Fig. 6 is a view showing an example of a backrest angle adjusting means that can be applied to the shampoo chair of the present invention. Referring to Fig. 6, the backrest angle adjusting means 50 is comprised of a shaft 51 passing through the lower portion of the backrest 20, a ratchet wheel 52 mounted on an inner end of the shaft 51 inside of the armrest 40, a ratchet 53 controlling the rotation of the ratchet wheel 52, and a lever 54 connected to the ratchet 53 for controlling the movement of the ratchet 53. The backrest angle adjusting means 50 is useful to fold and store the backrest 20 and the seat 10 or to adjust the angle of the backrest 20 to allow the position of a user to be comfortable.

Fig. 7 is a view showing an example of a support leg folding means that can be applied to the shampoo chair of the present invention. Referring to Fig. 7, a bottom of the seat 10 is comprised of a seat frame

10b and a seat bottom 10a extended inwardly from the frame 10b. The support legs 80 are attached to the seat 10 on both sides of the seat bottom 10a via the support leg folding means.

The support leg folding means is provided with a rotating shaft 81 that couples the support legs 80 to the seat frame 10b to allow the support legs 80 to be folded. In this case, the support legs 80 can be made to be elastically folded or unfolded by mounting a spring (not shown) or the like on the rotating shaft 81.

On the seat bottom 10a, there are mounted an elastic holder lOd for accommodating and holding the folded support legs 80, and a plurality of stopper blocks 11 hingedly attached to receiving depressions 10c and used to prevent the folded support legs 80 from being arbitrarily unfolded. In this case, the stopper blocks 11 are accommodated in the receiving depressions 10c when the shampoo chair of the present invention is not in use. With the above-described construction, the support legs 80 are unfolded from the seat bottom 10a, and can be secured by the stopper blocks 11 projected from the receiving depressions 10c. When the support legs 80 are kept folded on the seat bottom 10a, the stopper blocks 11 attached to the seat bottom 10a are inserted into the receiving depressions 10c and both support legs 80 are pushed into the elastic holders lOd attached to the seat bottom 10a.

Although the shampoo chair according to an embodiment of the present invention is described with reference to Figs. 1 to 7, the shampoo chair of the present invention can be variously changed. In particular, although the rotating members connecting the neck rest to the backrest to allow the neck rest to change its position are described with reference to Figs. 3 and 4 as an example, such rotating members can be variously modified. Such modification is described with reference to Figs. 8 to 15 hereinafter. In this case, for ease of explanation, the same reference numerals are used to designate the same components having the same functions. Referring to Fig. 8, spherical ends 32'a formed on one-side ends of rotating members 32' are fixedly inserted into the holding sockets of the holding socket blocks 31c, while the other-side ends are directly connected to the backrest 20.

Referring to Fig. 9, projection blocks 32c are formed on the middle portion of rotating members 32, so the rotation angles of the spherical ends 32'a

are limited to certain ranges.

Referring to Fig. 10, rotating members 32'" are comprised of first rods

32" 'a whose one-side ends are fastened to the neck rest 31 ' and second rods 32" 'b whose one-side ends are fastened to the backrest 20. Additionally, spherical ends are formed on the other-side ends of the first and second rods

32" 'a and 32'"b.

The first and second rods 32" 'a and 32" 'b are connected to each other through holding socket blocks 32" 'c having holding sockets. As shown in Figs. 8, 9 and 10, the holding socket blocks are provided with the spherical holding sockets, and the spherical ends of the rotating members can be easily combined with the holding socket blocks by being interference-fitted into the holding sockets. However, they can be combined with each other in a different manner as shown in Figs. 11 to 13. Referring to Fig. 11, sawtooth-shaped grooves 33"ab are formed on an outer surface of a spherical end of a rotating member 32 inserted into a holding socket block 33 'a formed at one end of a support member 33' along the direction of rotation, and the holding socket block 33 'a is provided with a rotation restricting means 33 'b that can restrict and control the rotation range of the spherical end 32'a by being inserted into or removed from the sawtooth-shaped grooves 33"ab.

As an example, the rotation restricting means 33 'b is comprised of a rotation shaft 33 'be fixed in the holding socket block 33 'a and a manipulation lever rotated around the rotation shaft 33 'be and designed to allow its one end 33 'ba to be inserted into or removed from the grooves 33"ab and its other end 33 'bb to be manipulated from the outside.

Referring to Figs. 12 and 13, a holding socket block 133 is comprised of a split ring 133b brought into contact with the spherical end 32a, a friction member 133c that has a large friction coefficient in comparison with that of the ring 133b and be brought into contact with the spherical end 32a over the ring 133b, a first cylindrical receiving cap 133d adapted to accommodate the ring 133b and the friction member 133c and externally threaded, and a second receiving cap 133a internally threaded to be engaged with the first receiving cap 133d and provided with a projection 133ab inwardly protruded to keep the ring 133b from being removed from the first receiving cap 133d.

The ring 133b has a C-shaped form such that it can be elastically inserted into the spherical end 32a. The friction member 133c is made of material having a large friction coefficient (for example, rubber) in comparison with that of the ring 133b (for example, plastic) so as to keep the ball-shaped, spherical end 32a from slipping. A reference number 133e designates a part of the backrest 20 or neck rest 31 to which the holding socket block 133 is fastened. In such a case, the holding socket block 133 is combined with the backrest 20 or neck rest 31 in a screw fashion. Referring to Fig. 14, as another modification of the rotating members, rotating members 34 can be pliable rods 34a whose both-side ends 34aa and 34ab are fastened to the neck rest 31 and the support member 33", respectively. In this case, the pliable rods 34a are manufactured in the form of rods of certain thickness by using relatively pliable material such as aluminum, tin or rubber. When pliable rods of metallic material are employed, the pliable rods 34a are preferably coated with coating 34b such as high polymer resin to protect the soft rods and improve their pliability.

The pliable rods 34a can be easily bent by a user's hand due to the pliability thereof, so the position of the neck rest 31 can be easily and freely changed.

Referring to Fig. 15, flexible tubes are employed as rotating members, instead of pliable rods 34a of Fig. 14. The flexible tubes 34c are fastened at their one-side ends 34ca to the neck rest 31 and at their other-side ends 34cb to the support member 33 " . In such a case, the flexible tubes 34c are examples of members that allow the position of the neck rest 31 to be easily changed according to the convenience of a user. The flexible tubes 34c are fabricated in the form of tubes by continuously combining protruded and depressed tube members together. Although the shampoo chair according to the present invention is described in detail with reference to Figs. 1 to 15, the shampoo chair of the present invention is not limited to the embodiments above described. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims, and the scope of the present invention is to be determined solely by the accompanying claims.

Industrial Applicability As described above, the present invention provides a shampoo chair, which does not cause discomfort to a washed person by keeping his neck portion from being brought into contact with a sink, and which can be freely and conveniently utilized regardless of the physical differences among washed persons. Additionally, the shampoo chair of the present invention can be minimized in its volume and is convenient for transport and storage, so it can be easily and conveniently utilized for infants and the weak and old at home or in hospitals.

Claims

1. A shampoo chair having a seat and a backrest, comprising: a neck rest; and one or more rotating members connecting the neck rest and the backrest to allow a position of the neck rest to be changed.

2. The shampoo chair according to claim 1, wherein the rotating members, the neck rest and/or the backrest are connected to each other in a ball joint fashion.

3. The shampoo chair according to claim 2, wherein: the rotating members are provided at their one-side ends with first spherical ends and at their other-ends with second spherical ends; the neck rest is provided with a first holding socket block having first holding sockets in which the first spherical ends of the rotating members are rotatably supported; and the backrest is provided with a second holding socket block having second holding sockets in which the second spherical ends of the rotating members are rotatably supported.

4. The shampoo chair according to claim 3, wherein the rotating members further comprise projections formed between the first and second spherical ends to restrict rotation of the neck rest to a certain range.

5. The shampoo chair according to claim 3, wherein the first and/or second holding sockets are formed by rings and friction members having a large friction coefficient in comparison with the rings.

6. The shampoo chair according to claim 3, wherein: the second spherical ends are each provided with at least one groove along a direction of rotation; and the second holding socket blocks are each provided with a rotation shaft and a manipulation lever rotated around the rotation shaft and designed to allow its one end to be inserted into or removed from the groove and its other end to be manipulated from the outside.

7. The shampoo chair according to claim 2, wherein the rotating members each comprise: a first rod whose one end is fastened to the neck rest and whose other end constitutes a third spherical end; a second rod whose one end is fastened to the neck rest and whose other end constitutes a fourth spherical end; and a third holding socket block provided with a third holding socket for rotatably holding the third spherical end of the first rod and a fourth holding socket for rotatably holding the fourth spherical end of the second rod, thereby connecting the first and second rods.

8. The shampoo chair according to claim 1, wherein the rotating members are pliable rods whose one-side ends are fastened to the neck rest and whose other-side ends are fastened to the backrest.

9. The shampoo chair according to claim 8, wherein the pliable rods are coated with high polymer resin.

10. The shampoo chair according to claim 1, wherein the rotating members are flexible tubes whose one-side ends are fastened to the neck rest and whose other-side ends are fastened to the backrest.

11. The shampoo chair according to any of claims 2, 8 and 10, further comprising a height adjusting means attached to the backrest to support the rotating members and adjust their height.

12. The shampoo chair according to claim 11, wherein the neck rest comprises: a neck rest cover provided with forwardly projected side ends, a rearwardly and roundly slanted rear portion, and one or more drain grooves; and a cushion contained in the neck rest cover.

13. The shampoo chair according to any of claims 2, 8 and 10, further comprising: a backrest angle adjusting means mounted on an armrest for folding the backrest and the seat and controlling a slant angle of the backrest; an auxiliary leg rotatably mounted on a back surface of the backrest for supporting the backrest; an auxiliary seat mounted on a front surface of the backrest to be folded; support legs mounted on a bottom surface of the seat for supporting the seat and the backrest on the ground; and a support leg folding means for folding the support legs onto the bottom surface of the seat.