KR101539018B1 - A multi-functional wheelchair and the comprising method thereof - Google Patents

Abstract

The present invention relates to a multi-functional wheelchair, and a configuration method thereof. The present invention controls a height of the wheelchair with an air cylinder, a slope of a back rest, a rotation width of a seat, a support or components of the wheelchair comprising an assembly thereof when an impaired person or a mobility impaired user uses the wheelchair. Therefore, the present invention provides convenience when a patient uses the wheelchair, and the patient sitting on the wheelchair can switch positions to another position lying on a bed in order to enable the mobility impaired patient to conveniently be inspected more without an inconvenience of moving from the wheelchair to the bed when the patient is inspected with various tests at a hospital. Moreover, the present invention is capable of reducing the exhaustion of physical strength of a guardian, a caregiver, or a hospital staff taking care of the patient.

Description

TECHNICAL FIELD [0001] The present invention relates to a multifunctional wheelchair,

The present invention relates to a multifunctional wheelchair and a method of constructing the same. More particularly, the present invention relates to a multifunctional wheelchair and a method of constructing the same, and more particularly, Control, or a combination of these, to provide convenience in the use of a patient's wheelchair and to switch from a sitting in a wheelchair to a lying position in a bed, The present invention relates to a multifunctional wheelchair capable of performing a convenient examination without having the inconvenience of moving from a wheelchair to a bed and also capable of reducing the physical power consumption of the caregiver, .

With the advancement of modern medical technology and medical equipment, human diseases that can be cured are increasing day by day, which is lengthening human life span. Especially, among the medical equipments, the wheelchair is a wheel chair so that a person who can not move his or her legs can move freely, and the technology of the wheelchair is developed by the development of modern medical equipment technology. The conventional wheelchair can be moved by manually rolling the wheels of the wheelchair while the user is seated on the wheelchair seat. The volume of the wheelchair can be reduced or enlarged through the folding link by connecting the left and right main frames of the wheelchair. And it is easy to store and manage.

However, in the case of the above-mentioned wheelchair, there is an inconvenience that a person with an uncomfortable mobility who is confined to a general chair shape has to descend from a wheelchair and ascend and descend into a test bed when he or she takes various tests in a hospital.

Korean Patent Laid-Open Publication No. 2009-0079111 (2009.07.21), as a prior art document, suggests a switchable wheelchair capable of changing the structure. This prior art document discloses a vehicle comprising a pair of left and right main frames rotatably mounted on a front wheel and a rear wheel, the main frame being interconnected via at least one pair of folding links to be foldable in an advantageous form to a vehicle mount; A pair of parallel spaced apart links mounted between the pair of left and right main frames, the pair of hinge shafts being pivotal points and having a structure capable of refracting in a form advantageous for user boarding or favorable seating; And wherein the prime link mounted between the pair of main frames is disposed in a form favorable to the user's ride or can be refracted in a favorable form to a sitting posture so that the prime link can be operated between the pair of left and right main frames And a plurality of pairs of driven links connecting the plurality of pairs. However, the prior art has a problem in that the structure of the wheelchair is complicated and the number of structures used for the wheelchair is large, resulting in a large cost.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a wheelchair which is capable of adjusting a height of a wheelchair by an air cylinder, a tilt of a backrest, The present invention provides a wheelchair which can be easily changed from a sitting position to a lying position on a bed.

Still another object of the present invention is to provide a simple structure for a wheelchair including a height adjustment by a pneumatic cylinder of a wheelchair, a tilt adjustment of a backrest, a rotation width adjustment of a seat, .

Still another object of the present invention is to provide a method of constructing a wheelchair that can reduce the physical power consumption of the caregiver, caregiver, or hospital personnel taking care of the patient due to the adjustment of the components of the wheelchair.

A multifunction wheelchair according to an embodiment of the present invention includes a head rest portion for supporting or protecting a head or neck of a user by touching a back portion of the user's head; A backrest portion connected parallel to the headrest portion and supporting or protecting the back or waist of the user by touching the back or back of the user; A seat portion vertically connected to the backrest portion to support or protect the hips or the thighs by contacting the user's hips or thighs; An armrest portion connected perpendicularly to the seat portion to support or protect a user's arm; An air cylinder unit vertically connected to the seat unit to adjust the height of the seat unit by linearly reciprocating upward and downward the air pressure inside the seat unit; A foot part connected perpendicularly to the seat part to support or protect a user's foot; A main frame part vertically connected to the air cylinder part and supporting the head rest part, the backrest part, the seat part, the arm rest part, the air cylinder part and the foot part; A front wheel portion vertically connected to the main frame portion and adapted to rotate on a ground; And a rear wheel portion vertically connected to the main frame portion and driven by a user to turn the wheel by hand. The control portion controls the inclination of the backrest portion, adjusts the height of the seat portion, adjusts the rotation width of the seat portion, And the posture of the user is changed from the wheelchair mode to the bed mode to the posture by rotating the seat portion to adjust the direction of the bed.

According to another aspect of the present invention, there is provided a backrest according to the first aspect of the present invention, wherein grooves are formed in the left and right sides on the left and right sides of the back surface, And is formed perpendicular to the substrate.

The backrest according to another embodiment of the present invention is characterized in that the support is fixed by a fixing method including a fixing pin, a fixing support, or a combination thereof in order to prevent sudden detachment of the support received in the groove. do.

Further, the backrest according to another embodiment of the present invention is characterized in that the backrest has a wide lower surface to prevent the support from moving on the ground when the tilt is adjusted to switch from the wheelchair mode to the bed mode.

Further, the air cylinder part according to another embodiment of the present invention may include a circular plate connected to the lower surface of the seat part to transmit the force of the air pressure applied when reciprocating linear movement of the air cylinder part to the circular plate, Can be controlled.

The armrest according to another embodiment of the present invention is characterized in that the armrest switch is formed such that the frame connected to the seat part is connected to the front or rear part by a hinge shaft and folded.

Further, according to another embodiment of the present invention, the footrest is connected to the seat portion and the hinge shaft so that the inclination of the backrest portion is adjusted so as to be on the same line as the seat portion when the mode is changed from the wheelchair mode to the bed mode. .

Further, the seat portion and the backrest portion according to another embodiment of the present invention are vertically connected to each other, so that the rotation angle of the seat portion can be adjusted by rotating the seat portion at an arbitrary angle up to 360 degrees.

According to still another aspect of the present invention, there is provided a method of configuring a multi-functional wheelchair, the method comprising: constructing a headrest to support or protect a head or neck of a user by touching a rear portion of the user's head; Forming a backrest which is connected to the headrest in parallel to support the back or waist of the user by touching the back or back of the user; Forming a seat that is perpendicular to the backrest to support or protect the hips or thighs of the user's hips or thighs; Forming an armrest perpendicular to the seat to support or protect a user's arm; Constructing an air cylinder connected vertically to the seat to regulate the height of the seat by linearly reciprocating upward and downward air pressure inside the seat; Constructing a footrest vertically connected to the seat to support or protect a user's foot; Forming a main frame vertically connected to the air cylinder to support a head restraint, a backrest, a seat, an armrest, an air cylinder, and a footrest; Constructing a front wheel connected to the main frame vertically so that the wheel runs on the ground; And adjusting a tilt of the backrest, adjusting a height of the seat, adjusting a rotation width of the seat, and adjusting a rotation angle of the seat. That is, the seat portion is rotated to adjust the direction of the bed, thereby changing the posture of the user from the wheelchair mode to the bed mode.

The present invention adjusts a wheelchair component including a height adjustment by a pneumatic cylinder of a wheelchair, a tilt adjustment of a backrest, a rotation width of a seat, or a support pedal so that a patient, a disabled person or an uncomfortable person can sit comfortably in a wheelchair And it is possible to switch from a sitting position to a lying position in a wheelchair by adjusting the constituent elements of the wheelchair. Therefore, it is not inconvenient to move from a wheelchair to a bed when a patient having an uncomfortable movement performs various tests at a hospital, In addition, it is possible to use the wheelchair alone without the help of the other person. In addition, it is possible to reduce the physical power consumption of the caregiver, caregiver or hospital personnel caring for the patient, furthermore, the height adjustment by the air cylinder of the wheelchair, Adjustment of the tilt of the seat, adjustment of the rotation width of the seat, Providing a simpler architecture for flexible configuration of hamhan wheelchair and there is an effect that can reduce the manufacturing cost of a wheelchair.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exemplary view showing a front view of a multifunction wheelchair according to an embodiment of the present invention; Fig.
2 illustrates an example of a rear view of a multifunction wheelchair in accordance with an embodiment of the present invention.
Figure 3 is an illustration of a side view of a multifunction wheelchair in accordance with an embodiment of the present invention.
FIG. 4 is an illustration showing a bed mode of a multifunction wheelchair according to an embodiment of the present invention; FIG.
FIG. 5 is a flowchart showing a method of switching a multi-function wheelchair from a wheelchair mode to a bed mode according to an embodiment of the present invention; FIG.

Hereinafter, an embodiment of a multifunction wheelchair according to the present invention and a method of constructing the same will be described with reference to the accompanying drawings.

1 is a front view of a multifunction wheelchair according to an embodiment of the present invention.

The wheelchair 10 includes a headrest 100, a backrest 200, a seat 300, an armrest 400, an air cylinder 500, a main frame 600, a footrest 700 , A front wheel portion 800, a rear wheel portion 900, or a combination thereof.

First, the head rest part 100 is connected to the upper end of the backrest part in parallel so that the rear end of the head of the user of the wheel chair touches the head rest or the user's head or neck. At this time, the head rest portion and the backrest portion may be connected to each other in parallel by a frame. The backrest part 200 is connected to the headrest part and connected to the seat part by a slope having a vertical or arbitrary angle so as to support or protect the back or back of the user, have. Also, although not shown in the drawings, a handle is formed on the upper surface of the backrest portion so that a caregiver or a caregiver can hold the handle of the wheelchair and move the wheelchair. The seat portion 300 is connected to the backrest portion and is in contact with the user's hips or thighs and has a relatively flat shape to support or protect the user's hips or thighs. Here, the backrest portion and the seat portion can be made of a material including leather, synthetic leather, vinyl, waterproof material, or a combination thereof, and there is no limitation on the material. Also, as shown in the figure, the backrest portion and the seat portion of the wheelchair are connected to each other so that the rotational range of the seat portion can be rotated by adjusting the angle of 360 degrees at an arbitrary angle. The armrest portion 400 is formed parallel to the upper portions of both left and right sides of the seat portion, and can support or protect the arm of the wheelchair user. As shown in the figure, the air cylinder unit 500 is vertically connected to the lower surface of the seat part and the main frame, and the height of the seat part can be adjusted by moving the air cylinder up and down. In this case, compressed air is contained in the air cylinder, so that the energy of the compressed air can be converted into a mechanical reciprocating linear motion, and the height of the seat portion can be adjusted up and down. The main frame 600 may be vertically connected to the air cylinders, the front wheels, and the rear wheels to support the seat, the front wheels, and the rear wheels of the wheelchair. The footrest 700 may be vertically connected to the lower surface of the seat portion to support and protect the wheelchair user's feet. The front wheel part 800 and the rear wheel part 900 show the front wheel and the rear wheel of the wheelchair. The front wheel part is vertically connected to the lower side of both the left and right sides of the main frame, and the rear wheel part is vertically connected to both left and right ends of the main frame. have. At this time, the rear wheel part uses a wheel larger than the front wheel part because the wheelchair user must rotate the wheel of the rear wheel part by hand, and the front wheel part is driven by the auxiliary wheel of the rear wheel part wheel to help the rear wheel part. Can be used.

2 is an exemplary view showing a rear surface of a multifunction wheelchair according to an embodiment of the present invention.

As shown in FIG. 2, at least two wheelchair support members 210 are formed on the back side of the backrest of the wheelchair, and a circular plate 510 is formed on the air cylinder 500. As shown in the figure, the wheelchair support 210 is connected to a hinge shaft so as to be folded and housed in both left and right grooves of the back of the backrest. When the wheelchair mode is changed from the wheelchair mode to the bed mode, The posture of the user can be switched to the lying position on the bed by supporting the seat portion substantially in parallel. At this time, when the inclination of the backrest portion of the wheelchair reaches a predetermined inclination, the support of the wheelchair can be automatically released from the back of the backrest portion and can be extended vertically to the ground. On the other hand, when the inclination of the backrest portion of the wheelchair is set to a certain value When the tilt is reached, the support vertically extended to the ground can be retracted back into the groove of the backrest. Also, although not shown in the drawings, the wheelchair support may be secured by various fixing methods including a locking pin, a locking support, or a combination thereof to prevent sudden detachment of the wheelchair support from the back of the backrest. As shown in the drawing, a circular plate 510 is formed on the upper portion of the air cylinder 500 to transmit the force of reciprocating linear motion of the air cylinder, that is, the air pressure to the circular plate so as to adjust the height of the seat portion of the wheelchair, Can be adjusted. Although not shown in the drawings, the height of the seat portion is adjusted by moving the height adjusting knob connected to the air cylinder up and down to apply air pressure to the air cylinder, thereby transmitting the reciprocating linear motion of the cylinder to the circular plate, .

3 is an exemplary view showing a side view of a multifunction wheelchair according to an embodiment of the present invention.

3, the armrest portion and the seat portion of the wheelchair are vertically connected to each other by a frame, and an armrest switch 410 is formed on the armrest portion. At this time, the armrest switch 410 may be formed on the right and left sides of the armrest or on one of the armrests, and the number of armrest switches is not limited. As shown in the drawing, the armrest switch is connected to a hinge axis so that the frame connected to the armrest portion and the seat portion is folded forward or backward when the switch of the armrest portion is pressed. When switching from the wheelchair mode to the bed mode, The height of the sheet portion can be made the same. And conversely, when switching from the bed mode to the wheelchair mode, the armrest can be formed by connecting the armrest portion and the seat portion vertically by pressing the armrest switch once more. Also, the backrest portion of the wheelchair can be adjusted to tilt at an arbitrary angle as shown in the figure. Although not shown in the drawing, in order to adjust the inclination of the backrest, the backrest can be switched from the wheelchair mode to the bed mode posture by moving the tilt adjustment knob connected to the backrest of the wheelchair back and forth.

FIG. 4 is an exemplary view showing a bed mode of a multifunction wheelchair according to an embodiment of the present invention.

As shown in FIG. 4, when the wheelchair mode is switched to the bed mode, the wheelchair support 210 housed in the back of the backrest is formed perpendicular to the floor to support the backrest, and the backrest can be formed substantially parallel to the seat . The wheelchair support may be formed of a variety of materials including wood, metal, or a combination thereof, and the wheelchair support may have a wide lower surface to prevent the wheelchair from moving on the ground. Further, the armrest portion may be formed at the same height as the seat portion by operating the armrest switch or may be formed on the seat portion. Also, the footrest 700 may be formed in parallel with a hinge shaft connecting the foot plate and the seat portion so that the foot plate 700 is on the same plane as the seat portion, that is, on an extension of the seat portion. Here, the wheelchair mode can be switched to the bed mode due to the deformation of the support, the footrest and the footrest of the wheelchair.

FIG. 5 is a flowchart illustrating a method for switching a multifunction wheelchair according to an embodiment of the present invention from a wheelchair mode to a bed mode.

A method of changing from the wheelchair mode to the bed mode by adjusting the height of the wheelchair, adjusting the inclination of the backrest, or adjusting the rotation width of the seat in the state where the patient, the disabled, or the uncomfortable user is seated in the wheelchair is as follows.

First, a user with an uncomfortable seat is seated in a wheelchair. The user who is seated in the wheelchair adjusts the height of the seat portion by adjusting the height adjusting knob of the seat portion up and down (S100). Thereafter, the tilt adjustment knob of the backrest is adjusted back and forth to adjust the inclination of the backrest (S200). At this time, when the inclination of the backrest reaches an arbitrary inclination value set in advance, the wheelchair supporting frame housed in the back of the backrest is detached from the back surface of the backrest and is perpendicular to the ground. At this time, the inclination of the backrest is almost parallel to the seat (S300). Also, since the footrest is deformed together with the inclination of the backrest, if the inclination of the backrest is maintained in a parallel state, the footrest is placed on the same plane as the seatrestire, that is, on the extension of the seatportion (S400). After that, the armrest is folded by pressing the armrest switch of the armrest part once to convert the user's posture from the wheelchair mode to the bed mode posture (S500). The method of switching from the wheelchair mode to the bed mode is not limited to the order of operating the wheelchair component including the backrest, the seat portion, the armrest portion or the footstool portion, and can operate the wheelchair component at the user's discretion.

The present invention adjusts a wheelchair component including a height adjustment by a pneumatic cylinder of a wheelchair, a tilt adjustment of a backrest, a rotation width of a seat, or a support pedal so that a patient, a disabled person or an uncomfortable person can sit comfortably in a wheelchair And it is possible to switch from a sitting position to a lying position in a wheelchair by adjusting the constituent elements of the wheelchair. Therefore, it is not inconvenient to move from a wheelchair to a bed when a patient having an uncomfortable movement performs various tests at a hospital, In addition, it is possible to use the wheelchair alone without the help of the other person. In addition, it is possible to reduce the physical power consumption of the caregiver, caregiver or hospital personnel caring for the patient, furthermore, the height adjustment by the air cylinder of the wheelchair, Adjustment of the tilt of the seat, adjustment of the rotation width of the seat, Providing a simpler architecture for flexible configuration of hamhan wheelchair and has the advantage of reducing the manufacturing cost of a wheelchair.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. .

10: Wheelchair 100: Head rest
200: backrest 210: support
300: seat portion 400: armrest portion
410: armrest switch 500: air cylinder
510: Circle plate 600: Main frame
700: footstool part 800: front wheel part
900: Rear portion

Claims (10)

A head rest portion (100) for supporting or protecting the head or the neck of the user's back;
A backrest part 200 connected parallel to the headrest part 100 to support or protect the back or waist of the user by touching the back or back of the user;
A seat portion 300 vertically connected to the backrest portion 200 to support or protect the hips or the thighs by contacting the user's hips or thighs;
An air cylinder unit 500 connected vertically to the seat unit 300 and capable of adjusting the height of the seat unit 300 by converting the air pressure therein into up and down reciprocating linear motion;
The backrest 200 and the seat 300 are supported by a hinge shaft so as to be folded and housed in both left and right grooves of the back of the backrest 200. When the seat is changed from the wheelchair mode to bed mode, When the inclination of the backrest 200 reaches a predetermined inclination, the backrest 200 is automatically lifted from the back of the backrest 200 and spreads vertically to the ground. In contrast, when the backrest 200 is inclined at an arbitrary angle A wheelchair support (not shown) which can be fixed by using a fixing pin or a fixed support to prevent it from being suddenly detached from the backrest 200 when the tilt is reached, 210);
The armrest switch 410 is formed so as to be vertically connected to the seat portion 300 to support or protect the arm of the user and to fold the frame connected to the seat portion 300 by the hinge shaft (400);
A foot part 700 vertically connected to the seat part 300 to support or protect the user's feet;
The headrest 100, the backrest 200, the seat 300, the armrest 400, the air cylinder 400, and the air cylinder 400. The air cylinder 500 is vertically connected to the two rear wheels 900, A main frame part 600 supporting the cylinder part 500 and the foot part 700;
A front wheel part 800 vertically connected to the main frame part 600 and adapted to rotate on the ground;
A rear wheel unit 900 connected to the main frame unit 600 and driven by a user to turn the wheel by hand; And
And an armrest switch (410) attached to the armrest portion (400)
The armrest portion 400 and the seat portion 300 are connected to each other by a hinge shaft so that the frame connected to the armrest portion 400 and the seat portion 300 is folded into a front portion or a rear portion. When the mode is changed from the wheelchair mode to the bed mode, It is possible to form the same height as the portion 300,
A circular plate connected to the lower surface of the seat part 300 may be formed to transmit the force of the air pressure applied during the reciprocating linear motion of the air cylinder part 500 to the circular plate to adjust the height of the seat part 300 ,
The posture of the user can be changed from the wheelchair mode to the bed mode by adjusting the inclination of the backrest part 200, adjusting the height of the seat part 300, or adjusting the direction of the bed by rotating the seat part 300 In the bed mode, the backrest 200 is folded back to the bed mode by changing the inclination of the backrest 200, and the height of the seat 300 is adjusted to adjust the backrest 200 and the seat 300 , Or by changing the direction of the bed by rotating the seat portion 300 in the bed mode, the user's posture is changed from the wheelchair mode to the bed mode to the posture by changing the wheelchair mode to the bed mode Multifunctional wheelchair. The method according to claim 1,
The backrest part 200 includes:
And a support table 210 connected to the grooves by a hinge shaft is received in the grooves so as to be perpendicular to the ground according to the inclination of the backrest 200,
The support table 210 is fixed by a fixing method including a fixing pin, a fixing support, or a combination thereof to prevent the support table 210 accommodated in the groove from suddenly disengaging,
Wherein the support base (210) is made of a wide lower surface so as to prevent the support base (210) from moving on the ground when changing from the wheelchair mode to the bed mode by adjusting the inclination. delete delete The method according to claim 1,
The footrest part (700)
Wherein the seat portion (300) is connected to the seat portion (300) by a hinge shaft so that the backrest portion (200) is inclined so that the backrest portion (200) bathchair. Constructing a head restraint (100) for supporting or protecting the head or neck by touching the back of the user's head;
Constructing a backrest (200) connected in parallel with the headrest (100) to support or protect the back or waist of the user by touching the back or back of the user;
Configuring a seat (300) perpendicular to the back (200) to support or protect the hips or thighs by touching the user ' s hips or thighs;
The backrest 200 and the seat 300 are supported by the hinge shaft so as to be folded and housed in the left and right side grooves on the back side of the backrest 200 and extended vertically to the ground when the mode is changed from the wheelchair mode to the bed mode, When the inclination of the backrest 200 reaches a predetermined inclination, the backrest 200 is automatically released from the back surface of the backrest 200 and spreads vertically to the ground. On the contrary, when the inclination of the backrest 200 is set to a certain value A wheelchair support 210 that can be fixed by using a fixing pin or a fixed support to prevent the user from suddenly falling off from the back 200 ;
And an armrest switch 410 coupled to the seat 300 so as to support or protect the arm of the user and to fold the frame connected to the seat 300 by a hinge shaft );
Constructing an air cylinder (500) vertically connected to the seat (300) and converting the air pressure contained therein into a reciprocating linear motion to adjust the height of the seat (300);
Constructing a footrest (700) vertically connected to the seat (300) to support or protect a user ' s foot;
A backrest 200, a seat 300, an armrest 400, an air cylinder 500, and a footrest 700 (not shown) A main frame 600 supporting the main frame 600;
Configuring a front wheel (800) connected to the main frame (600) vertically to rotate the wheels on the ground;
Constructing a rear wheel (900) vertically connected to the main frame (600) so that a user rotates the wheel by hand; And
Attaching an armrest switch (410) to the armrest (400)
The armrests 400 and the frames connected to the seat 300 are connected to each other by a hinge shaft so as to be folded forward or backward so that when the mode is changed from the wheelchair mode to bed mode, ), As shown in Fig.
A circular plate connected to the lower surface of the seat 300 may be formed to transmit the force of the air pressure applied when the air cylinder 500 reciprocates linearly to the circular plate to adjust the height of the seat 300,
The posture of the user is changed from the wheelchair mode to the bed mode to the posture by adjusting the inclination of the backrest 200, adjusting the height of the seat 300 or adjusting the direction of the bed by rotating the seat 300, To change the posture in the bed mode, the backrest 200 is tilted so that the backrest 200 is shifted from the wheelchair mode to the bed mode, or the height of the seat 300 is adjusted by adjusting the height of the seat 300, Wherein the user's posture is changed from the wheelchair mode to the bed mode to the posture by switching the mode from bed mode to bed mode or by rotating the seat (300) in the bed mode. The method of claim 6,
The step of configuring the back (200)
The backrest 200 has grooves formed in the left and right sides on the left and right sides of the back surface. The grooves 210 and the hinge shaft 210 are received in the grooves. The grooves 210 and the backrests 200 are perpendicular to the ground surface.
The support table 210 is fixed by a fixing method including a fixing pin, a fixing support, or a combination thereof to prevent the support table 210 accommodated in the groove from suddenly disengaging,
Wherein the support base (210) is made of a wide lower surface so as to prevent the support base (210) from moving on the ground when changing the wheelchair mode to the bed mode by adjusting the inclination. delete delete The method of claim 6,
The step of constructing the foot plate (700)
Characterized in that the seat (300) is connected to the seat (300) by a hinge shaft so that the inclination of the backrest (200) is adjusted so as to be on the same line of extension as the seat (300) Way.

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