GB2533935A

GB2533935A - Folding Chair

Info

Publication number: GB2533935A
Application number: GB1500159.7A
Authority: GB
Inventors: Yin Qing-Kun; Meng Fanxiang
Original assignee: Individual
Current assignee: Individual
Priority date: 2015-01-07
Filing date: 2015-01-07
Publication date: 2016-07-13
Anticipated expiration: 2035-01-07
Also published as: GB2533935B

Abstract

A folding chair comprising a base 10, two side panels extending upwardly from the base 10, a seat 40 pivotally mounted between the side panels such that it can move from a horizontal to a vertical position, a backrest 50 mounted on the base 10 such that it can move up and down, a powered control device for moving the backrest 50 and an upper cover 70 pivotally mounted to the side panels above the seat 40 wherein the upper cover 70 can be rotated upwardly and the backrest 50 can be moved upwardly to be in front of the upper cover 70 in this position. The unit may employ curved levers, wheels and torsion springs to link movement of the various parts. Contact switches may be used to control the power supply and a motor employ a threaded rod. The device may fold down to a box or trunk shape or form part of a cabinet.

Description

FOLDING CHAIR

1. Field of the Invention

The present invention relates to a chair, especially to a folding chair.

2. Description of the Prior Arts

A folding chair is usually used in small spaces, and is folded when not in use to save the storage space. With reference to Figs. 19 and 20, one of the most common and conventional folding chairs comprises a first bracket 10A, a second bracket 20A and a seat 30. The first and second brackets10A, 20A are pivotally connected to each other. The seat 30A is pivotally connected to the first bracket 10A, and selectively upward abuts the second bracket 20A for a user to be seated on the seat 30A. The first and second brackets 10A, 20A are relatively rotated to be parallel with each other such that the folding chair is folded. However, the conventional folding chair has the following shortcomings.

First, when folded, the conventional folding chair cannot stand without external support, but has to lean on a wall or any other object, which is not convenient for storage.

Second, the front-rear thickness of the conventional folding chair can be reduced when the folding chair is folded, but the height cannot be shortened and may be even increased.

To overcome the shortcomings, the present invention provides a folding chair to mitigate or obviate the aforementioned problems.

The main objective of the present invention is to provide a folding chair that can stand without external support when folded and can reduce its height when folded.

The folding chair has a bottom seat, two side panels, a seat assembly, a back support assembly, a power device and an upper cover. The side panels are respectively and uprightly mounted on two transverse sides of the bottom seat. The seat assembly is pivotally mounted between the side panels, is forward rotatable to be horizontal relative to the side panels, and is backward rotatable to be upright relative to the side panels. The back support assembly is up-and-down moveably mounted on the bottom seat, and is disposed in back of the seat assembly. The power device is mounted on the bottom seat for moving the back support assembly up and down. The upper cover is pivotally mounted on at least one of the side panels, is disposed above the seat assembly, and is upward and backward rotatable. When the upper cover is rotated upward and backward, the back support assembly is moved upward to be in front of the upper cover.

The bottom seat keeps abutting on the ground regardless that the folding chair is folded or unfolded, thereby ensuring the folding chair can stand without external support when folded. In addition, the back support assembly is up-and-down movably mounted on the bottom seat, such that when the folding chair is folded and the back support assembly is moved downward, the overall height is reduced. Moreover, since the overall height is reduced after the folding chair is folded, the upper cover may be used for placement of objects or as a desk, thereby providing multiple functions.

Other objectives, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

IN THE DRAWINGS

Fig. 1 is a perspective view of a folding chair in accordance with the present invention; Fig. 2 is a partial exploded perspective view of the folding chair in Fig. 1; Fig. 3 is a partial perspective view of an inner panel body of the folding chair in Fig 1; Fig. 4 is a partial side view of the folding chair in Fig. 1, shown folded; Fig. 5 is a partial side view of the folding chair in Fig. 1, shown expanded; Fig. 6 is a partial perspective view of an upper recover unit and a lower recover unit of the folding chair in Fig. 1; Fig. 7 is a partial perspective view of a lever unit of the folding chair in Fig. 1; Fig. 8 is a partial perspective view of a lever torsion spring of the folding chair in Fig 1; Fig. 9 is a first operational view of the upper recover unit and the lower recover unit of the folding chair in Fig. 1; Fig. 10 is a second operational view of the upper recover unit and the lower recover unit of the folding chair in Fig. 1; Fig.11 is a third operational view of the upper recover unit and the lower recover unit of the folding chair in Fig. 1; Fig. 12 is a partial perspective view of an upper cover torsion spring of the folding chair in Fig. 1; Fig. 13 is a partial side view of an upper cover of the folding chair in Fig. 1, shown folded; Fig. 14 is a partial side view of the upper cover of the folding chair in Fig. 1, shown expanded; Fig. 15 is a front view of a power device of the folding chair in Fig. 1; Fig. 16 is a top view in partial section of a back support assembly of the folding chair in Fig. 1; Fig. 17 is an operational view of a cabinet and two folding chairs in Fig. 1, shown folded; Fig. 18 is an operational view of the cabinet and the folding chairs in Fig. 1, shown expanded; Fig. 19 is a side view of a conventional folding chair in accordance with the prior art, shown expanded; and Fig. 20 is a side view of the conventional folding chair in Fig. 19, shown folded.

With reference to Figs. 1 and 2, a folding chair in accordance with the present invention comprises a bottom seat 10, two side panels 20, a back panel 30, a seat assembly 40, a back support assembly 50, a power device 60 and an upper cover 70.

The side panels 20 are respectively and uprightly mounted on two transverse sides of the bottom seat 10.

The back panel 30 is uprightly mounted on a back side of the bottom seat 10, and is connected between the side panels 20. In another preferred embodiment, the folding chair may be implemented without the back panel 30.

With reference to Figs. 2, 4 and 5, the seat assembly 40 is pivotally mounted between the side panels 20, is disposed in the front of the bottom seat 10, is forward rotatable to be horizontal relative to the side panels 20, and is backward rotatable to be upright relative to the side panels 20.

The back support assembly 50 is up-and-down moveably mounted on the bottom seat 10, is disposed in the back of the bottom seat 10, and is disposed in the back of the seat assembly 40.

The power device 60 is mounted on the bottom seat 10, and is capable of moving the back support assembly 50 up and down.

The upper cover 70 is pivotally mounted on at least one of the side panels 20, is disposed above the seat assembly 40, and is upward and backward rotatable. When the upper cover 70 is rotated upward and backward, the back support assembly 50 can be moved upward to be in front of the upper cover 70 as shown in Fig. 5.

With reference to Figs. 3 to 5, in a preferred embodiment, each side panel has an inner panel body 22 and two channel end panels 23. The seat assembly 40 is pivotally mounted between the inner panel bodies 22 of the side panels 20. Each inner panel body 22 has a channel groove 221. The channel groove 221 extends as a 90-degree curve, and has a lower end and a rear end. The lower end is disposed aligned with and below a pivot junction between the inner panel body 22 and the seat assembly 40 as shown in Fig. 4. The rear end is disposed aligned with and in back of the pivot junction between the inner panel body 22 and the seat assembly 40 as shown in Fig. 4. The channel end panels 23 are mounted on the inner panel body 22, and are respectively disposed on the lower end and the rear end of the channel groove 221. Each channel end panel 23 has an abutting recess 231 formed in a side of the channel end panel 23, and each channel end panel 23 is made of elastomer.

The seat assembly 40 further has two channel pins 41. The channel pins 41 respectively protrude from two transverse sides of the seat assembly 40, and are respectively mounted in the channel grooves 221 of the side panels 20. Each channel pin 41 is selectively mounted in and abuts the abutting recess 231 of the corresponding channel end panel 23. When the seat assembly 40 is rotated forward to be horizontal, the channel pin 41 abuts the rear end of the channel groove 221 and obtains firm support by abutting the abutting recess 231 of the corresponding channel end panel 23. When the seat assembly 40 is rotated backward to be upright, the channel pin 41 abuts the lower end of the channel groove 221 and obtains firm support by abutting the abutting recess 231 of the other channel end panel 23. In addition, the elastomeric channel end panel 23 also can absorb shocks and sounds.

With reference to Fig. 6, an upper recover unit 42 and a lower recover unit 43 are mounted on the back of the seat assembly 40. When the seat assembly 40 is rotated to be horizontal, the upper recover unit 42 is curved backward and upward, and the lower recover unit 43 is curved backward and downward. The lower recover unit 43 is disposed below the upper recover unit 42. An opening is formed between the lower recover unit 43 and the upper recover unit 42.

With reference to Figs. 7 and 9 to 11, a lever unit 24 is pivotally mounted on an inner surface of the inner panel body 22 of one of the side panels 20, and has a lower wheel 241 and an abutting panel 242. The lower wheel 241 is pivotally mounted transversely and inward on a front end of the lever unit 24, is mounted between the lower recover unit 43 and the upper recover unit 42, and slidably and upward abuts the lower recover unit 43 to rotate the seat assembly 40 backward to be upright as shown in Figs. 9 to 11. The abutting panel 242 is transversely and inward mounted on a rear end of the lever unit 24. With reference to Figs. 7 to 9, a lever torsion spring 25 is mounted around a pivot junction between the lever unit 24 and the side panel 20, and has a first end and a second end. The first end is securely connected to the lever unit 24, and the second end is securely connected to the side panel 20 as shown in Fig. 8, thereby rotating upward the front end of the lever unit 24. Therefore, the lower wheel 241 abuts the lower recover unit 43 and does not depart from the opening between the lower recover unit 43 and the upper recover unit 42.

With reference to Figs. 6, 7 and 9 to 11, an upper wheel 51 and a pressing unit 52 are mounted on a bottom of the back support assembly 50. The upper wheel 51 selectively and slidably abuts downward the upper recover unit 42 to rotate the seat assembly 40 backward as shown in Fig. 9. The pressing unit 52 is disposed in back of the upper wheel 51, and selectively and downward abuts the abutting panel 242 to rotate the front end of the lever unit 24 upward to further rotate the seat assembly 40 backward to be horizontal as shown in Fig. 11.

With reference to Fig. 6, when the seat assembly 40 is rotated to be horizontal, the upper wheel 51 abuts downward a top surface of the upper recover unit 42 at a position adjacent to a front end of the upper recover unit 42. With reference to Fig. 9, when the back support assembly 50 is moved downward, the upper wheel 51 presses downward the upper recover unit 42, and moves along the curved top surface of the upper recover unit 42, thereby rotating the upper recover unit 42 and the seat assembly 40 upward and backward. With reference to Fig. 10, when the upper wheel 51 slides to a rear end of the upper recover unit 42 to depart from the upper recover unit 42, the seat assembly 40 has not been rotated to the upright position yet. However, at this time, the pressing unit 52 presses downward the abutting panel 242, which is on the rear end of the lever unit 24, to make the lower wheel 241, which is on the front end of the lever unit 42, abuts upward the lower recover unit 43, thereby keeping rotating the seat assembly 40 upward. With reference to Fig. 11, finally, when the back support assembly 50 is moved downward to a lowest position of a movement route, the lever unit 24 rotates the seat assembly 40 upward such that the seat assembly 40 is upright.

To rotate the seat assembly 40 from being upright to horizontal, the seat assembly 40 leans forward by its own weight. When the seat assembly 40 is upright, the lower wheel 241, which is on the front end of the lever unit 24, abuts upward the lower recover unit 43 to keep the seat assembly 40 upright. With reference to Fig. 10, when the back support assembly 50 is moved upward, the lever unit 24 is gradually rotated with the ascending of the pressing unit 52, and thus the seat assembly 40 leans forward gradually. With reference to Fig. 9, after the upper recover unit 42 upward abuts the upper wheel 51, the upper wheel 51 and the upper recover unit 42 control the degree of the forward leaning of the seat assembly 40. With reference to Fig. 6, finally, the back support assembly 50 is moved upward to a highest position of the movement route. At this time, the upper wheel 51 abuts the top surface of the upper recover unit 42 at a position adjacent to the front end of the upper recover unit 42, and the seat assembly 40 is rotated to be horizontal. Therefore, the folding chair does not need any dedicated actuating mechanism for rotating the seat assembly 40, thereby simplifying the structure and reducing the cost.

With reference to Figs. 1,2 and 17, in a preferred embodiment, the folding chair may be used alone, or assembled with other devices together for use. When the folding chair is used alone, each side panel 20 further has an outer panel body 21. The outer panel body 21 is mounted on an outer surface of the inner panel body 22, and the upper cover 70 is pivotally connected between the outer panel bodies 21 of the side panels 20. With reference to Fig. 17, the folding chair is assembled with other devices together for use. For example, a cabinet 90 is mounted in a transverse side of the folding chair, and the side panel 20 that is adjacent to the cabinet 90 may be implemented without the outer panel body 21. Instead, the upper cover 70 is pivotally connected between the outer panel body 21 of the other side panel 20 and an outer surface of the cabinet 90, thereby saving the material cost and further reducing the overall transverse width of the folding chair.

With reference to Figs. 12 to 14, in a preferred embodiment, an upper cover torsion spring 26 is mounted between a bottom of the upper cover 70 and the outer panel body 21 of one of the side panels 20 to rotate the upper cover 70 forward to be horizontal. When the back support assembly 50 is moved upward, the back support assembly 50 directly pushes the upper cover 70 upward and backward and indirectly presses the upper cover torsion spring 26. When the back support assembly 50 is moved downward, the upper cover torsion spring 26 rotates the upper cover 70 forward to be horizontal. Therefore, the folding chair does not need any dedicated actuating mechanism to rotate the upper cover 70, thereby simplifying the structure and reducing the cost.

With reference to Figs. 2,3, 15 and 16, in a preferred embodiment, the power device 60 has a motor 61 and a threaded rod 62. The motor 61 is mounted securely on the bottom seat 10.

The threaded rod 62 extends upward from the motor 61 and is actuated by the motor 61.

Two limit strips 31 are mounted on an inner surface of the back panel 30, extend vertically, and are transversely arranged apart from each other.

A moving unit 54 and two limit units 53 are mounted on a back surface of the back support assembly 50 as shown in Fig. 16. The moving unit 54 is mounted around and screwed with the threaded rod 62 of the power device 60. The limit units 53 are respectively up-and-down movably mounted around and engage with the limit strips 31.

The engagement between the limit units 53 and the limit strips 31 prevents the back support assembly 50 and the moving unit 54 from being rotated with the threaded rod 62. Thus, the moving unit 54 and the back support assembly 50 are moved up-and-down relative to the threaded rod 62 when the threaded rod 62 is rotated.

With reference to Figs. 1 and 2, in a preferred embodiment, a main switch 80 is mounted on one of the side panels 20 for switching on the motor 61 of the power device 60. The main switch 80 is preferably, but not limited to, a knob switch. In addition, the main switch 80 also may be a press switch or any other kind of switch.

With reference to Figs. 3 and 15, an upper contact switch 32 and a lower contact switch 33 are mounted on the inner surface of the back panel 30 for switching off the motor 61 of the power device 60. The lower contact switch 33 is disposed below the upper contact switch 32.

25 30 35 Two actuating segments 541 are respectively mounted on a top of a side and a bottom of the other side of the moving unit 54. The back support assembly 50 selectively actuates the contact switches 32, 33 by the actuating segments 541. When one of the actuating segments 541 of the back support assembly 50 actuates the upper contact switch 32 as shown in Fig. 3, the seat assembly 40 is horizontal, and the back support assembly 50 is in the highest position of the movement route. When the other actuating segment 541 of the back support assembly 50 actuates the lower contact switch 33 as shown in Fig. 15, the seat assembly 40 is upright, and the back support assembly 50 is in the lowest position of the movement route.

With reference to Figs. 3 to 5 and 15, the seat assembly 40 is upright and the back support assembly 50 is in the lowest position of the movement route. The user rotates the main switch 80, and then the motor 61 rotates the threaded rod 62 to move the back support assembly 50 upward. In addition, the seat assembly 40 gradually leans forward, and the upper cover 70 is gradually pushed backward as mentioned above. The motor 61 stops rotating the threaded rod 62 automatically when the actuating segment 541 actuates the upper contact switch 32. At this time, the seat assembly 40 is horizontal, and the back support assembly 50 pushes the upper cover 70 outward and is in the highest position of the movement route. When the user reversely rotates the main switch 80, the motor 61 reversely rotates the threaded rod 62 to move the back support assembly 50 downward. The seat assembly 40 is gradually rotated backward and upward, and the upper cover 70 is gradually rotated forward. The motor 61 stops rotating the threaded rod 62 automatically when the other actuating segment 541 actuates the lower contact switch 33. At this time, the seat assembly 40 is upright, the back support assembly 50 is in the lowest position of the movement route, and the upper cover 70 is rotated forward to be horizontal. Therefore, the folding chair does not need a high-precision motor 61 to control the movement of the back support assembly 50. Instead, the folding chair can move the back support assembly 50 to specific position and further rotate the seat assembly 40 and the upper cover 70 to specific angle by the main switch 80 and the contact switches 32, 33, both of which are structurally and functionally simple, thereby reducing the manufacturing cost.

With reference to Figs. 1 and 2, the bottom seat 10 keeps abutting on the ground regardless the folding chair is folded or unfolded, thereby ensuring the folding chair can stand without external support when folded. With reference to Figs. 4 and 5, in addition, the back support assembly 50 is up-and-down movably mounted on the bottom seat 10, such that when the folding chair is folded and the back support assembly 50 is moved downward, the overall height is reduced. Moreover, since the overall height is reduced after the folding chair is folded, the upper cover 70 may be used for placement of objects or as a desk, thereby providing multiple functions.

B

With reference to Figs. 17 and 18, as mentioned above, the folding chair may be assembled with a cabinet 90. Preferably, two folding chairs may be respectively assembled in both transverse sides of the cabinet 90, such that the upper covers 70 of the folding chairs and a top cover 91 of the cabinet 90 form a common plane, which may be used as a bar counter.

When the folding chairs are unfolded for use as chairs, the upper cover 91 of the cabinet 90 may be used as a desk for placement of objects. In addition, when the upper cover 91 of the cabinet 90 is rotated upward, an accommodating space on a top of the cabinet 90 is exposed for placement of objects. A drawer 92 and a shelf 95, both of which can be pulled out, are mounted on a front surface of the cabinet 90. When this assembly of the cabinet 90 and the folding chairs is installed in carriers for transportation, such as a vehicle, a ship, or an airplane, the cabinet 90 may be further equipped with a CD player 93 and air conditioner vent 94. User can put CD, DVD and so on into the player 93, and music or movie can be played via speakers or screens in the transportation carrier.

Claims

CLAIMS: 1. A folding chair comprising: a bottom seat (10); two side panels (20) respectively and uprightly mounted on two transverse sides of the bottom seat (10); a seat assembly (40) pivotally mounted between the side panels (20), being forward rotatable to be horizontal relative to the side panels (20), and being backward rotatable to be upright relative to the side panels (20); a back support assembly (50) up-and-down moveably mounted on the bottom seat (10), and disposed in back of the seat assembly (40); a power device (60) mounted on the bottom seat (10) for moving the back support assembly (50) up and down; and an upper cover (70) pivotally mounted on at least one of the side panels (20), disposed above the seat assembly (40), and being upward and backward rotatable; wherein when the upper cover (70) is rotated upward and backward, the back support assembly (50) is moved upward to be in front of the upper cover (70).
2. The folding chair as claimed in claim 1 further comprising: an upper recover unit (42) mounted on a back of the seat assembly (40); wherein when the seat assembly (40) is rotated to be horizontal, the upper recover unit (42) is curved backward and upward; and an upper wheel (51) mounted on a bottom of the back support assembly (50), selectively and slidably downward abutting the upper recover unit (42) to rotate the seat assembly (40) 25 backward.
3. The folding chair as claimed in claim 2 further comprising: a lever unit (24) pivotally mounted on an inner surface of one of the side panels (20), and having a lower wheel (241) pivotally mounted transversely and inward on a front end of the lever unit (24); and an abutting panel (242) transversely and inward mounted on a rear end of the lever unit (24); a lower recover unit (43) mounted on the back of the seat assembly (40); wherein when the seat assembly (40) is rotated to be horizontal, the lower recover unit (43) is curved backward and downward and disposed below the upper recover unit (42); an opening is formed between the lower recover unit (43) and the upper recover unit (42); the lower wheel (241) is mounted between the lower recover unit (43) and the upper recover unit (42) and slidably and upward abuts the lower recover unit (43) to rotate the seat assembly (40) backward to be upright; and a pressing unit (52) mounted on the bottom of the back support assembly (50), selectively and downward abutting the abutting panel (242) to rotate the front end of the lever unit (24) upward to further rotate the seat assembly (40) backward to be horizontal.
4. The folding chair as claimed in claim 3 further comprising a lever torsion spring (25) mounted around a pivot junction between the lever unit (24) and the side panel (20), and having: a first end securely connected to the lever unit (24); and a second end securely connected to the side panel (20) to rotate the front end of the lever unit (24) upward to further make the lower wheel (241) abut the lower recover unit (43).
5. The folding chair as claimed in any claim of claims 1 to 4 further comprising a back panel (30) uprightly mounted on a back side of the bottom seat (10) and connected between the side panels (20).
6. The folding chair as claimed in claim 5 further comprising: at least one limit strip (31) mounted on an inner surface of the back panel (30) and extending vertically; and at least one limit unit (53) mounted on a back surface of the back support assembly (50); each limit unit (53) up-and-down movably mounted around and engaging with a corresponding limit strip (31).
7. The folding chair as claimed in claim 6 further comprising: an upper contact switch (32) mounted on the inner surface of the back panel (30) for switching off the power device (60); and a lower contact switch (33) mounted on the inner surface of the back panel (30) and disposed below the upper contact switch (32) for switching off the power device (60); wherein the back support assembly (50) selectively actuates the upper contact switch (32) or the lower contact switch (33); when the back support assembly (50) actuates the upper contact switch (32), the seat assembly (40) is horizontal, and the back support assembly (50) is in a highest position of a movement route; when the back support assembly (50) actuates the lower contact switch (33), the seat assembly (40) is upright, and the back support assembly (50) is in a lowest position of the movement route.
8. The folding chair as claimed in any claim of claims 1 to 7 further comprising a main switch (80) mounted on one of the side panels (20) for switching on the power device (60).
9. The folding chair as claimed in any claim of claims 1 to 8, wherein the power device (60) has a motor (61) mounted on the bottom seat (10), and a threaded rod (62) extending upward from the motor (61) and actuated by the motor (61); and a moving unit (54) mounted on a back surface of the back support assembly (50), and mounted around and screwed with the threaded rod (62).
10. The folding chair as claimed in any claim of claims 1 to 9, wherein each side panel (20) has an inner panel body (22) pivotally connected to the seat assembly (40), and having a channel groove (221) extending as a 90-degree curve, and having a lower end disposed aligned with and below a pivot junction between the inner panel body (22) and the seat assembly (40); and a rear end disposed aligned with and in back of the pivot junction between the inner panel body (22) and the seat assembly (40); and the seat assembly (40) further has two channel pins (41) respectively protruding from two transverse sides of the seat assembly (40), and respectively mounted in the channel grooves (221) of the side panels (20).
11. The folding chair as claimed in claim 10, wherein each side panel (20) further has two channel end panels (23) mounted on the inner panel body (22) and respectively disposed on the lower end and the rear end of the channel groove (221); each channel end panel (23) having an abutting recess (231) formed in a side of the channel end panel (23); and the channel pin (41) of the seat assembly (40) selectively mounted in and abutting the abutting recess (231) of the corresponding channel end panel (23).
12. The folding chair as claimed in claim 11, wherein the channel end panel (23) is made of elastomer.
13. The folding chair as claimed in any claim of claims 10 to 12, wherein one of the side panels (20) further has an outer panel body (21) mounted on an outer surface of the inner panel body (22) and pivotally connected to the upper cover (70).
14. The folding chair as claimed in any claim of claims 10 to 12, wherein each side panel (20) further has an outer panel body (21) mounted on an outer surface of the inner panel body (22) and pivotally connected to the upper cover (70).
15. The folding chair as claimed in any claim of claims 1 to 14 further comprising an upper cover torsion spring (26) mounted between a bottom of the upper cover (70) and one of the side panels (20) to rotate the upper cover (70) forward to be horizontal; wherein when the back support assembly (50) is moved upward, the back support assembly (50) pushes the upper cover (70) upward and backward.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWSCLAIMS: A folding chair comprising: a base (10); two side panels (20) respectively and uprightly mounted on two transverse sides of the base (10); a seat assembly (40) pivotally mounted between the side panels (20), being forward pivotable relative to the side panels (20) to be horizontal, and being backward pivotable relative to the side panels (20) to be upright; a backrest (50) up-and-down moveably mounted on the base (10), and disposed in rear of the seat assembly (40); a power device (60) mounted on the base (10) for moving the backrest (50) up and down; and an upper cover (70) pivotally mounted on at least one of the side panels (20), disposed above the seat assembly (40), and being upward and backward pivotable; wherein when the upper cover (70) is pivoted upward and backward, the back rest (50) is moved upward to be in front of the upper cover (70).cr) 2. The folding chair as claimed in claim 1 further comprising: an upper recover unit (42) mounted on a back of the seat assembly (40); wherein when the seat co assembly (40) is pivoted to be horizontal, the upper recover unit (42) is curved backward and upward; and an upper wheel (51) mounted on a bottom of the backrest (50), selectively and slidably downward o CO abutting the upper recover unit (42) to pivot the seat assembly (40) backward.The folding chair as claimed in claim 2 further comprising: a lever unit (24) pivotally mounted on an inner surface of one of the side panels (20), and having a lower wheel (241) pivotally mounted transversely and inward on a front end of the lever unit (24); and an abutting panel (242) transversely and inward mounted on a rear end of the lever unit (24); a lower recover unit (43) mounted on the back of the seat assembly (40); wherein when the seat assembly (40) is pivoted to be horizontal, the lower recover unit (43) is curved backward and downward and disposed below the upper recover unit (42); an opening is formed between the lower recover unit (43) and the upper recover unit (42); the lower wheel (241) is mounted between the lower recover unit (43) and the upper recover unit (42) and slidably and upward abuts the lower recover unit (43) to pivot the seat assembly (40) backward to be upright; and a pressing unit (52) mounted on the bottom of the backrest (50), selectively and downward abutting the abutting panel (242) to pivot the front end of the lever unit (24) upward to further pivot the seat assembly (40) backward to be horizontal.4. The folding chair as claimed in claim 3 further comprising a lever torsion spring (25) mounted around a pivot junction between the lever unit (24) and the side panel (20), and having: a first end securely connected to the lever unit (24); and a second end securely connected to the side panel (20) to pivot the front end of the lever unit (24) upward to further make the lower wheel (241) abut the lower recover unit (43).The folding chair as claimed in any one of claims 1 to 4 further comprising a back panel (30) uprightly mounted on a back side of the base (10) and connected between the side panels (20).6. The folding chair as claimed in claim 5 further comprising: at least one limit strip (31) mounted on an inner surface of the back panel (30) and extending vertically; and at least one limit unit (53) mounted on a back surface of the backrest (50); each limit unit (53) up-and-down movably mounted around and engaging with a corresponding limit strip (31).7. The folding chair as claimed in claim 6 further comprising: an upper contact switch (32) mounted on the inner surface of the back panel (30) for switching off the power device (60); and cr) a lower contact switch (33) mounted on the inner surface of the back panel (30) and disposed below the upper contact switch (32) for switching off the power device (60); co wherein the backrest (50) selectively actuates the upper contact switch (32) or the lower contact switch (33); when the backrest (50) actuates the upper contact switch (32), the seat assembly (40) is horizontal, and the backrest (50) is in a highest position of a movement route; when the backrest o CO (50) actuates the lower contact switch (33), the seat assembly (40) is upright, and the backrest (50) is in a lowest position of the movement route.8. The folding chair as claimed in any one of claims 1 to 7 further comprising a main switch (80) mounted on one of the side panels (20) for switching on the power device (60).The folding chair as claimed in any one of claims 1 to 8, wherein the power device (60) has a motor (61) mounted on the base (10); and a threaded rod (62) extending upward from the motor (61) and actuated by the motor (61); and a moving unit (54) mounted on a back surface of the backrest (50), and mounted around and screwed with the threaded rod (62).10. The folding chair as claimed in any one of claims 1 to 9, wherein each side panel (20) has an inner panel body (22) pivotally connected to the seat assembly (40), and having a channel groove (221) extending as a 90-degree curve, and having a lower end disposed aligned with and below a pivot junction between the inner panel body (22) and the seat assembly (40); and cr) 12. 13. coo CO 14. 15.a rear end disposed aligned with and in rear of the pivot junction between the inner panel body (22) and the seat assembly (40); and the seat assembly (40) further has two channel pins (41) respectively protruding from two transverse sides of the seat assembly (40), and respectively mounted in the channel grooves (221) of the side panels (20).The folding chair as claimed in claim 10, wherein each side panel (20) further has two channel end panels (23) mounted on the inner panel body (22) and respectively disposed on the lower end and the rear end of the channel groove (221); each channel end panel (23) having an abutting recess (231) formed in a side of the channel end panel (23); and the channel pin (41) of the seat assembly (40) selectively mounted in and abutting the abutting recess (231) of the corresponding channel end panel (23).The folding chair as claimed in claim 11, wherein the channel end panel (23) is made of elastomer.The folding chair as claimed in any one of claims 10 to 12, wherein one of the side panels (20) further has an outer panel body (21) mounted on an outer surface of the inner panel body (22) and pivotally connected to the upper cover (70).The folding chair as claimed in any one of claims 10 to 12, wherein each side panel (20) further has an outer panel body (21) mounted on an outer surface of the inner panel body (22) and pivotally connected to the upper cover (70).The folding chair as claimed in any one of claims 1 to 14 further comprising an upper cover torsion spring (26) mounted between a bottom of the upper cover (70) and one of the side panels (20) to pivot the upper cover (70) forward to be horizontal; wherein when the backrest (50) is moved upward, the backrest (50) pushes the upper cover (70) upward and backward.