GB2515545A

GB2515545A - Foldable leg rest

Info

Publication number: GB2515545A
Application number: GB1311533.2A
Authority: GB
Inventors: qing-kun Yin; Chin-Chen Chang
Original assignee: WAN YU LI
Current assignee: WAN YU LI
Priority date: 2013-06-27
Filing date: 2013-06-27
Publication date: 2014-12-31
Anticipated expiration: 2033-06-27
Also published as: GB201311533D0; GB2515545B

Abstract

A two part folding leg rest each with its own drive mechanismA foldable leg rest comprising a slide base 20 with a mechanism 70 to lift it, a first pivoting frame 30 attached to the front of the slide base 20, a second pivoting frame 40 attached to the first pivoting frame and drive mechanisms 50 and 60 to actuate pivoting of the frames. The drive mechanisms 50 and 60 may be DC motors which utilise worm gears, standard gears and drive rods to drive movement of the leg rest. The lifting mechanism 70 may employ a threaded rod also driven by a direct current motor with a cooperating nut. A sliding assembly 10 may be mounted below the slide base 20 and may include two tracks 11 and two sliders 12 which can engage the tracks 11 and a motor driven drive mechanism 80 to actuate movement of the sliders 12. The leg rest may be used as part of a vehicle seat.

Description

FOLDABLE LEG REST

1. Field of the Invention

The present invention relates generally to chairs, and more particularly to a foldable leg rest applied to a chair for supporting the legs of a sitter in a stretched position.

2. Description of the Prior Arts

Chairs allow people to sit thereon and support weights of sitters. A conventional chair substantially comprises a seat and a backrest for supporting the bottom and the back of a sitter. The backrest may be adjustable in angle relative to the seat by an angle adjuster to fit different needs of different sitters.

However, when a person sits on the conventional chair for a long time, for example, on a long vehicle trip, the legs of the sitter will become tired and numb, or feel pain due to long time of bending. Accordingly, the conventional chair should be further improved to provide an enhanced comfort for the sifter.

The present invention provides a foldable leg rest that supports the legs of a sitter in a stretched position.

A foldable leg rest in accordance with the present invention comprises a slide base, a first folding assembly, a second folding assembly, a first-stage drive mechanism, a second-stage drive mechanism and a lifting device. The first folding assembly includes a first frame. The first frame has a front end and a rear end. The rear end of the first frame is pivotally connected to a front end of the slide base. The second folding assembly includes a second frame. The second frame has a rear end pivotally connected to the front end of the first frame. The first-stage drive mechanism is mounted on the slide base. The second-stage drive mechanism is mounted on the first frame. The lifting device is mounted below the slide base and includes at least one third-stage drivc mechanism. In use, the first-stage drive mechanism is actuated to pivot the first frame relative to the slide base and the second-stage drive mechanism is actuated to pivot the second frame relative to the first frame. Therefore, the legs of a sitter can be stretched and placed on the first and second frames, thereby enhancing comfort and minimizing fatigue. In addition, the at least one third-stage drive mechanism can be actuated to lift or lower the slide base such that the slide base is adjustable in angle relative to the horizontal plane, thus further enhancing comfort.

IN THE DRAWINGS: FIG. I is a perspective view of a foldable leg rest in accordance with the present invention shown in an unfolded state; FIG. 2 is another perspective view of the foldable leg rest of FIG. 1; FIG. 3 is a partially enlarged perspective view of the foldable leg rest of FIG 2; FIG. 4 is an enlarged perspective view of a first-stage drive mechanism of the foldable leg rest of FIG. 1; FIG. 5 is a partially enlarged perspective view of the first-stage drive mechanism of the foldable leg rest of FIG. 1; FIG. 6 is an enlarged perspective view of a second-stage drive mechanism of the foldable leg rest of FIG. 1; FIG. 7 is a partially enlarged exploded perspective view of the second-stage drive mechanism of the foldable leg rest of FIG. 1; FIG. 8 is another partially enlarged perspective view of the foldable leg rest of FIG. 2; FIG. 9 is an enlarged perspective view of a lifting device of the foldable leg rest of FIG 1; FIG. 10 is an enlarged perspective view of a fourth-stage drive mechanism of the foldable leg rest of FIG. 1; FIG 11 is a perspective view of a chair with the foldable leg rest of FIG. 1; FIG 12 is a side view of the foldable leg rest of FIG. I showing that the foldable leg rest is in a non-actuated state; FIGS. 13 to 17 are side views of the foldable leg rest of FIG. I showing that the foldable leg rest is in an actuated state; FIG. 18 is side view of the lifting device of the foldable leg rest of FIG. 1 showing that the lifting device is in a non-actuated state; and FIG. 19 is side view of the lifting device of the foldable leg rest of FIG. 1 showing that the lifting device is in an actuated state.

With reference to FIGS. 1 and 2, a foldable leg rest in accordance with the present invention comprises a sliding assembly 10, a slide base 20, a first folding assembly, a second folding assembly, a first-stage drive mechanism 50, a second-stage drive mechanism 60, a lifting device 70 and a fourth-stage drive mechanism 80.

The sliding assembly 10 includes two tracks 11 and two sliders 12. The tracks 11 are parallel to and spaced from each other. The sliders 12 respectively slidably engage the tracks 11.

The slide base 20 is mounted over the sliding assembly 10 and includes a front end, two side panels 21, a mounting board 22 and a connecting rod 23.

The side panels 21 are parallel to and spaced from each other and each side panel 21 has a top front edge, a front portion and a rear portion. The mounting board 22 has a bottom surface and opposite sides. The sides of the mounting board 22 are respectively secured to the top front edges of the side panels 21.

The connecting rod 23 has opposite ends respectively secured to the rear portions of the side panels 21.

With reference to FIG. 3, the first folding assembly includes a first frame 30, two pivot pieces 3 1, a rotating rod 32, a first first-stage contact member 33 and a second first-stage contact member 33A. The first frame 30 has opposite sides, a bottom surface, a front end and a rear end. The pivot pieces 31 are respectively disposed at opposite sides of the rear end of the first frame 30. The rear end of the first frame 30 is pivotally connected to the front end of the slide base 20 by the pivot pieces 31. The rotating rod 32 has opposite ends respectively secured to the pivot pieces 3 1. The first first-stage contact member 33 is secured to the rotating rod 32 adjacent to one of the ends of the rotating rod 32 and has a contact projection 331 extending therefrom. The second first-stage contact member 33A is secured to the rotating rod 32 adjacent to the other end of the rotating rod 32 and has a contact projection 33 lA extending therefrom.

With reference to FIGS. 1 and 2, the second folding assembly includes a second frame 40 having opposite sides and a rear end. Opposite sides of the rear end of the second frame 40 are pivotally connected to opposite sides of the front end of the first frame 30.

The first-stage drive mechanism 50 is mounted on the slide base 20, and is actuated to pivot the first frame 30 relative to the slide base 20. With reference to FIGS. 3 and 4, the first-stage drive mechanism 50 includes a first-stage DC motor 51, two first-stage gearings 52, a first first-stage contact switch 53 and a second first-stage contact switch 53A. The first-stage DC motor 51 is secured to a rear central portion of the bottom surface of the mounting board 22 of the slide base 20. Two flexible shafts 511 are respectively connected to opposite sides of the first-stage DC motor 5 1. The first-stage gearings 52 are respectively disposed at opposite sides of the bottom surface of the mounting board 22 of the slide base 20. The first-stage gearings 52 are disposed inside the slide base 20, not outside the first frame 30, such that the first frame 30 can be designed to have a width equal to the width of the slide base 20, thereby providing a big area for allowing the legs of a sitter to be placed thereon. Each first-stage gearing 52 has a mounting bracket 521 having an inner surface and a front portion. The mounting brackets 521 of the two first-stage gearings 52 are respectively secured to the front portions of the side panels 21 of the slide base 20.

With reference to FIG 5, the mounting bracket 521 receives a first-stage worm 522, a fist-stage worm gear 523, a first small gear 524, a first large gear 525, a first first-stage shaft 526 and a second first-stage shaft 527.

The first-stage worm 522 is driven by a corresponding flexible shaft 511 of the first-stage DC motor 5 1. The fist-stage worm gear 523 meshes with the first-stage worm 522. The first small gear 524 is coaxially mounted on the fist-stage worm gear 523. The first large gear 525 meshes with the first small gear 524. The first first-stage shaft 526 has an inner end and an outer end. The outer end of the first first-stage shaft 526 is coaxially mounted in the first large gear 525. The inner end of the first first-stage shaft 526 extends from the inner surface of the mounting bracket 521 and has a second small gear 5261 thereon.

The second first-stage shaft 527 is rotatably mounted on the front portion of the mounting bracket 521 and has an inner end. The inner end of the second first-stage shaft 527 extends from the inner surface of the mounting bracket 521 and has a second large gear 5271 thereon. The second large gear 5271 meshes with the second small gear 5261 and has an inner surface to which a rear portion of a corresponding pivot piece 3 1 is secured.

With reference to FIG 3, the first first-stage contact switch 53 and the second first-stage contact switch 53A are respectively secured to opposite sides of a front portion of the bottom surface of the mounting board 22 of the slide base 20. The first first-stage contact switch 53 is adjacent to the first first-stage contact member 33 such that the contact projection 331 of the first first-stage contact member 33 is contactable with the first first-stage contact switch 53.

The second first-stage contact switch 53A is adjacent to the second first-stage contact member 33A such that the contact projection 33 IA of the second first-stage contact member 33A is contactable with the second first-stage contact switch 53A.

With reference to FIG, 1, the second-stage drive mechanism 60 is mounted on the first frame 30, and is actuated to pivot the second frame 40 relative to the first frame 30. With reference to FIGS. 6 and 8, the second-stage drive mechanism 60 includes a second-stage DC motor 61, two second-stage drive rods 62, two second-stage gearings 63, a first second-stage contact switch 64, and a second second-stage contact switch 64A. The second-stage DC motor 61 is secured to a middle portion of the bottom surface of the first frame 30.

Two flexible shafts 611 are respectively connected to opposite sides of the second-stage DC motor 61. The second-stage drive rods 62 are respectively disposed at opposite sides of the bottom surface of the first frame 30. Each second-stage drive rod 62 is driven by a corresponding flexible shaft 611 of the second-stage DC motor 61 and has a worm 621 formed thereon distal from the second-stage DC motor 61. The second-stage gearings 63 are each respectively disposed between a front end of one of the sides of the first frame 30 and a rear end of one of the sides of the second frame 40. Each second-stage gearing 63 has a mounting housing 631 secured to the bottom surface of the first frame 30.

With further reference to FIG. 7, the mounting housing 631 receives a second-stage worm gear 632, a first second-stage gear 633 and a second second-stage gear 634. The second-stage worm gear 632 meshes with the worm 621 of a corresponding second-stage drive rod 62. The first second-stage gear 633 is coaxially mounted on the second-stage worm gear 632. The second second-stage gear 634 meshes with the first second-stage gear 633. Each second-stage gearing 63 further has a third second-stage gear 635, a second-stage shaft 636 and a connecting member 637. The third second-stage gear 635 meshes with the second second-stage gear 634. The second-stage shaft 636 is coaxially mounted through the third second-stage gear 635. The connecting member 637 is secured to the second-stage shaft 636 and has a

S

connecting piece 6371 extending therefrom. The connecting piece 6371 is secured to the rear end of a corresponding side of the second frame 40. The second-stage shaft 636 has an inner end extending from an inner surface of the third second-stage gear 635. A first second-stage contact member 638 and a second second-stage contact member 63 8A are respectively secured to the inner ends of the second-stage shafts 636 of the two second-stage gearings 63. The first second-stage contact member 638 has a contact projection 6381 extending therefrom. The second second-stage contact member 638A has a contact projection 6381 A extending therefrom.

The first second-stage contact switch 64 and the second second-stage contact switch 64A are respectively secured to opposite sides of a front portion of the bottom surface of the first frame 30. The first second-stage contact switch 64 is adjacent to the first second-stage contact member 638 such that the contact projection 6381 of the first second-stage contact member 638 is contactable with the first second-stage contact switch 64. The second second-stage contact switch 64A is adjacent to the second second-stage contact member 63 SA such that the contact projection 6381 A of the second second-stage contact member 638A is contactable with the second second-stage contact switch 64A.

With reference to FIG 1, the lifting device 70 is mounted between the sliding assembly 10 and the slide base 20, and is actuated to lift or lower the slide base 20 for allowing a sitter to adjust the angular position of the slide base relative to the horizontal plane, thereby enhancing sitting comfort. With reference to F1G 9, the lifting device 70 includes a mounting assembly 71, at least one third-stage drive mechanism 72 and at least one linkage assembly 73.

The mounting assembly 71 has two stationary panels 711, a stationary rod 712 and at least one mounting panel 713. The stationary panels 711 are respectively secured to the sliders 12 of the sliding assembly 10. The stationary rod 712 has opposite ends respectively secured to the stationary panels 711. The at least one mounting panel 713 is attached to the stationary rod 712 and has a tab 7131 extending downward therefrom.

The at least one third-stage drive mechanism 72 has a pivot mount 721, a third-stage DC motor 722, a third-stage threaded rod 723 and a third-stage nut 724. The pivot mount 721 has an end pivotally connected to the tab 7131 of the at least one mounting panel 713. The third-stage DC motor 722 is mounted on the pivot mount 721. The third-stage threaded rod 723 is driven by the third-stage DC motor 722. The third-stage nut 724 is screwed onto the third-stage threaded rod 723 and is longitudinally movable thereon. The at least one linkage assembly 73 is mounted between the third-stage nut 724 and the slide base 20, is driven by the moving third-stage nut 724, and has a linkage rod 731, two pivot arms 732 and two linkage arm members 733. The linkage rod 731 is rotatably mounted between the stationary panels 711 of the mounting assembly 71. The pivot arms 732 are spaced apart and each pivot arm 732 has opposite ends. One of the ends of each pivot arm 732 is pivotally connected to one of two opposite sides of the third-stage nut 724. The other end of each pivot arm 732 is secured to the linkage rod 731. The linkage arm members 733 are respectively disposed at opposite ends of the linkage rod 731 and each linkage arm member 733 has a lower arm 7331 and an upper arm 7332, each of the lower and the upper arms 7331, 7332 has opposite ends. One of the ends of the lower arm 7331 is secured to the linkage rod 731. The other end of the lower arm 7331 is pivotally connected to one of the ends of the upper arm 7332.

The other end of the upper arm 7332 is pivotally connected to the slide base 20.

In a preferred embodiment, the lifting device 70 includes two third-stage drive mechanisms 72, 72A and two linkage assemblies 73. The stationary rod 712 is secured to middle portions of the stationary panels 711.

One of the third-stage drive mechanisms 72 is located in front of the stationary rod 712 and the other third-stage drive mechanism 72A is located in back of the stationary rod 712. One of the linkage assemblies 73 is disposed at front ends of the stationary panels 711 adjacent to one of the third-stage drive mechanisms 72. The other linkage assembly 73 is disposed at rear ends of the stationary panels 711 adjacent to the other third-stage drive mechanism 72A. With further reference to FIG. 1, the upper arms 7332 of the linkage arm members 733 of one of the linkage assemblies 73 are pivotally connected to the bottom surface of the mounting board 22 of the slide base 20, and the upper arms 7332 of the linkage arm members 733 of the other linkage assembly 73 are pivotally connected to the connecting rod 23 of the slide base 20. The mounting assembly 71 has two mounting panels 713. One of the mounting panels 713 is mounted between the stationary rod 712 and the linkage rod 731 of one of the linkage assemblies 73. The other mounting panel 713 is mounted between the stationary rod 712 and the linkage rod 73 1 of the other linkage assembly 73.

With reference to FIG. 2, the fourth-stage drive mechanism 80 is mounted on a front end of the sliding assembly 10, and is actuated to slide the sliders 12 along the tracks 11 so as to make the slide base 20 slide along the tracks 11. With reference to FIG. 10, the fourth-stage drive mechanism 80 includes a fourth-stage DC motor 81. Two flexible shafts 811 are respectively connected to opposite sides of the fourth-stage DC motor 81 and slide the sliders 12 with the slide base 20 along the tracks 11. The technical means for driving the slide base 20 to slide along the tracks 11 is conventional and thus a

detailed description thereof will be omitted.

With reference to FIG. 11, the foldable leg rest in accordance with the present invention is applied to a chair that comprises a seat base 90 and a backrest 91. The tracks 11 of the sliding assembly 10 are secured to the seat base 90, and rear ends of the side panels 21 of the slide base 20 are pivotally connected to the backrest 91. With reference to FIG. 12, the leg rest is in a folded state. To unfold the leg rest, with reference to FIGS. 4, 5 and 13, the first-stage DC motor 51 is operated to rotate the first-stage worms 522 such that the first frame 30 can be pivoted forward relative to the slide base 20 with the transmission of the fist-stage worm gears 523, the first small gear 524, the first large gears 525, the second small gears 5261 and the second large gears 5271.

With reference to FIG 3, while the first frame 30 is being pivoted relative to the slide base 20, the rotating rod 32 secured to the first frame 30 rotates the first first-stage contact member 33 and the second first-stage contact member 33A. As the first frame 30 is pivoted forward 90 degrees relative to the slide base 20, the contact projection 331 of the first first-stage contact member 33 contacts the first first-stage contact switch 53, and the contact projection 33 1A of the second first-stage contact member 33A does not contact the second first-stage contact switch 53A, Thus, the first-stage DC motor 51 can be controlled to stop to ensure that the first frame 30 completes 90 degrees of pivoting.

With reference to FIGS. 6, 7 and 14, the second-stage DC motor 61 is operated to rotate the second-stage drive rods 62 such that the second frame 40 can be pivoted forward relative to the first frame 30 with the transmission of the second-stage worm gears 632, the first second-stage gears 633, the second second-stage gears 634, the third second-stage gears 635, the second-stage shafts 636 and the connecting members 637. While the second frame 40 is being pivoted, the first second-stage contact member 638 and the second second-stage contact member 638A secured to the second-stage shafts 636 are also rotated. With reference to FIGS. 8 and 15, as the second frame 40 is pivoted forward 180 degrees relative to the first frame 30, the contact projection 6381 of the first second-stage contact member 638 contacts the first second-stage contact switch 64 and the contact projection 638 1A of the second second-stage contact member 63 8A does not contact the second second-stage contact switch 64A. Thus, the second-stage DC motor 61 can be controlled to stop to ensure that the second frame 40 completes 180 degrees of pivoting.

With reference to FIG. 18, the third-stage DC motors 722 are operated to rotate the third-stage threaded rods 723 such that the third-stage nuts 724 can bc moved forward or backward along the third-stage threaded rods 723 with the threaded engagement between the third-stage threaded rods 723 and the third-stage nuts 724. While the third-stage nuts 724 are being moved, the pivot arms 732, the linkage rod 73 1 and the linkage arm members 733 are moved sequentially. With reference to FIGS. 16 and 19, the slide base 20 pivotally connected to the linkage arm members 733 can thus be lified.

With reference to FIGS. 10 and 17, the fourth-stage DC motor 81 is operated to slide the sliders 12 along the tracks 11 such that the slide base 20, the first frame 30 and the second frame 40 can be moved forward along the tracks 11 for allowing a sifter to adjust the space for sitting and leg stretching.

The leg rest in accordance with the present invention includes the folding assemblies to extend its length. Therefore, the legs of the sifter can be stretched and placed on the first and the second frames 30, 40, thereby enhancing comfort and minimizing fatigue. In addition, the slide base 20 can be lifted or lowered to adjust its angular position relative to the horizontal plane, thus further enhancing comfort.

To fold the leg rest, with reference to FIGS. 1 and 2, the fourth-stage DC motor 81 is operated to move the slide base 20, the first frame 30 and the second frame 40 backward along the tracks 11 of the sliding assembly 10. The third-stage DC motors 722 are operated to lower the slide base 20. The second-stage DC motor 61 is operated to pivot the second frame 40 toward the bottom surface of the first frame 30. The second frame 40 is pivoted until the contact projection 6381A of the second second-stage contact member 638A contacts the second second-stage contact switch 64A, The first-stage DC motor 51 is operated to pivot the first frame 30 backward. The first frame 30 is pivoted until the contact projection 33 1A of the second first-stage contact member 33A contacts the second first-stage contact switch 53A. Therefore, the area of the leg rest is reduced for convenience in storage and shipment.

Claims

CLAIMS: 1. A foldable leg rest comprising: a slide base (20); a first folding assembly including a first frame (30), the first frame (30) having: a front end; and a rear end pivotally connected to a front end of the slide base (20); a second folding assembly including a second frame (40), the second frame (40) having a rear end pivotally connected to the front end of the first frame (30); a first-stage drive mechanism (50) mounted on the slide base (20) and actuated to pivot the first frame (30) relative to the slide base (20); a second-stage drive mechanism (60) mounted on the first frame (30) and actuated to pivot the second frame (40) relative to the first frame (30); and a lifting device (70) mounted below the slide base (20) and including at least one third-stage drive mechanism (72) actuated to lift or lower the slide base (20).
2. The foldable leg rest as claimed in claim 1, wherein the first-stage drive mechanism (50) includes a first-stage DC motor (51); and two first-stage gearings (52) driven by the first-stage DC motor (51) such that the first frame (30) is pivoted.
3. The foldable leg rest as claimed in claim 2, wherein the second-stage drive mechanism (60) includes a second-stage DC motor (61); and two second-stage drive rods (62) and two second-stage gearings (63) driven by the second-stage DC motor (61) such that the second frame (40) is pivoted.
4. The foldable leg rest as claimed in claim 3, wherein the at least one third-stage drive mechanism (72) has a third-stage DC motor (722); a third-stage threaded rod (723) driven by the third-stage DC motor (722); and a third-stage nut (724) screwed onto the third-stage threaded rod (723) and being longitudinally movable thereon; and the lifting device (70) includes at least one linkage assembly (73) mounted between the third-stage nut (724) and the slide base (20), and driven by the moving third-stage nut (724) such that the slide base (20) is lifted or lowered.
5. The foldable leg rest as claimed in claim 4, wherein each first-stage gearing (52) of the first-stage drive mechanism (50) has a mounting bracket (521) secured to a front portion of the slide base (20), having an inner surface and a front portion, and receiving: a first-stage worm (522) driven by the first-stage DC motor (5 1); a fist-stage worm gear (523) meshing with the first-stage worm (522); a first small gear (524) coaxially mounted on the fist-stage worm gear (523); a first large gear (525) meshing with the first small gear (524); a first first-stage shaft (526) having: an outer end coaxially mounted in the first large gear (525); and an inner end extending from the inner surface of the mounting bracket (521) and having a second small gear (5261) thereon; arid a second first-stage shaft (527) rotatably mounted on the front portion of the mounting bracket (521), having an inner end extending from the inner surface of the mounting bracket (521), and having a second large gear (5271) thereon, and the second large gear (5271) meshing with the second small gear (5261); and the rear end of the first frame (30) is secured between the second largc gears (5271) of the two first-stage gearings (52) of the first-stage drive mechanism (50).
6. The foldable leg rest as claimed in claim 5, wherein each second-stage drive rod (62) of the second-stage drive mechanism (60) has a worm (621) formed thereon; and the second-stage gearings (63) of the second-stage drive mechanism (60) are mounted between the front end of the first frame (30) and the rear end of the second frame (40), and each second-stage gearing (63) has a mounting housing (631) secured to a bottom surface of the first frame (30) and receiving: a second-stage worm gear (632) meshing with the worm (621) of a corresponding second-stage drive rod (62); a first second-stage gear (633) coaxially mounted on the second-stage worm gear (632); and a second second-stage gear (634) meshing with the first second-stage gear (633); and each second-stage gearing (63) further has a third second-stage gear (635) meshing with the second second-stage gear (634); a second-stage shaft (636) coaxially mounted through the third second-stage gear (635); and a connecting member (637) secured to the second-stage shaft (636) and having a connecting piece (6371) extending therefrom and secured to the rear end of the second frame (40).
7. The foldable leg rest as claimed in claim 6, wherein the lifting device (70) includes a mounting assembly (71) having: two stationary panels (711); a stationary rod (712) having opposite ends respectively secured to the stationary panels (711); and at least one mounting panel (713) attached to the stationary rod (712); the at least one third-stage drive mechanism (72) has a pivot mount (721) pivotally connected to the at least one mounting panel (713) of the mounting assembly (71), and the third-stage DC motor (722) is mounted on the pivot mount (721); and the at least one linkage assembly (73) has a linkage rod (73 1) rotatably mounted between the stationary panels (711) of the mounting assembly (71); two pivot arms (732), and each pivot arm (732) having opposite ends, one of the ends of each pivot arm (732) pivotally connected to the third-stage nut (724) and the other end of each pivot arm (732) secured to the linkage rod (731); and two linkage arm members (733) respectively disposed at opposite ends of the linkage rod (731), and each linkage arm member (733) secured to the linkage rod (731) and pivotally connected to the slide base (20).
8. The foldable leg rest as claimed in claim 7, wherein the lifling device (70) includes two third-stage drive mechanisms (72, 72A) and two linkage assemblies (73), the stationary rod (712) is secured to middle portions of the stationary panels (711), one of the third-stage drive mechanisms (72) is located in front of the stationary rod (712) and the other third-stage drive mechanism (72A) is located in back of the stationary rod (712), one of the linkage assemblies (73) is disposed at front ends of the stationary panels (711) adjacent to one of the third-stage drive mechanisms (72) and the other linkage assembly (73) is disposed at rear ends of the stationary panels (711) ad] acent to the other third-stage drive mechanism (72A), the mounting assembly (71) has two mounting panels (713), and one of the mounting panels (713) is mounted between the stationary rod (712) and the linkage rod (73 1) of one of the linkage assemblies (73), and the other mounting panel (713) is mounted between the stationary rod (712) and the linkage rod (731) of the other linkage assembly (73).
9. The foldable leg rest as claimed in claim 8, wherein the first folding assembly includes a rotating rod (32) having opposite ends secured to the rear end of the first frame (30); a first first-stage contact member (33) secured to the rotating rod (32) adjacent to one of the ends of the rotating rod (32) and having a contact projection (331) extending therefrom; and a second first-stage contact member (33A) secured to the rotating rod (32) adjacent to the other end of the rotating rod (32) and having a contact projection (33 1A) extending therefrom; and the first-stage drive mechanism (50) includes a first first-stage contact switch (53) and a second first-stage contact switch (53A) respectively secured to the front portion of the slide base (20), the contact projection (331) of the first first-stage contact member (33) is contactable with the first first-stage contact switch (53) and the contact projection (33 1A) of the second first-stage contact member (33A) is contactabte with the second first-stage contact switch (53A).
10. The foldable leg rest as claimed in claim 9, wherein a first second-stage contact member (638) and a second second-stage contact member (63 8A) are respectively secured to the second-stage shafts (636) of the two second-stage gearings (63) of the second-stage drive mechanism (60), the first second-stage contact member (638) has a contact projection (6381) extending therefrom and the second second-stage contact member (63 8A) has a contact projection (6381 A) extending therefrom; and the second-stage drive mechanism (60) includes a first second-stage contact switch (64) and a second second-stage contact switch (64A) secured to a front portion of the first frame (30), the contact projection (6381) of the first second-stage contact member (638) is contactable with the first second-stage contact switch (64), and the contact projection (6381A) of the second second-stage contact member (63 8A) is contactable with the second second-stage contact switch (64A).
11. The foldable leg rest as claimed in any of claims 1 to 10 further comprising: a sliding assembly (10) mounted below the slide base (20) and including: two tracks (11); and two sliders (12) respectively slidably engaging the tracks (11); and a fourth-stage drive mechanism (80) mounted on a front end of the sliding assembly (10) and actuated to slide the sliders (12) along the tracks (11) so as to make the slide base (20) slide along the tracks (11).
12. The foldable leg rest as claimed in claim 11, wherein the fourth-stage drive mechanism (80) includes a fourth-stage DC motor (81) for driving the sliders (12).