Seat framework and working method thereof

Abstract

The invention relates to a seat framework and a working method thereof.The seat framework comprises a bottom frame, a lifting mechanism is arranged on the bottom frame, at least one front roller is arranged on the front side of the bottom frame, rear rollers are arranged on the left side and the right side of the tail end of the bottom frame respectively, supporting parts are vertically arranged on the left side and the right side of the tail end of the bottom frame respectively, and brake arms are rotationally arranged on the outer sides of the supporting parts; a linkage shaft is arranged at the top of the brake arm, a kidney-shaped hole allowing the linkage shaft to penetrate through is formed in the supporting part, a cam is rotationally arranged on the inner side of the supporting part and connected with the lifting mechanism, elastic pieces are connected to the left side and the right side of the bottom frame respectively, and the tail ends of the elastic pieces are connected to the bottom of the brake arm. The lifting mechanism drives the cam to rotate during lifting, and the cam forwards pushes the linkage shaft to enable the bottom of the brake arm to abut against the rear roller; when the seat framework is lifted, the seat can be self-locked, and a user can safely stand up from the seat.

Description

Technical Field

[0001] The invention relates to the technical field of seat accessories, and in particular to a seat frame and a working method thereof. Background Art

[0002] The seat frame of the prior art includes a bottom frame, on which a lifting mechanism is provided, and at least three rollers are provided at the bottom of the bottom frame. When the lifting mechanism is lifted, it is convenient for the user to stand up from the seat, but since the seat can still be moved by the rollers, the user may fall when standing up from the seat, resulting in poor safety. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a seat frame which can enable the seat to be self-locked when lifted, so that the user can stand up from the seat safely.

[0004] In order to solve the above technical problems, the present invention provides a seat frame, including a bottom frame, a lifting mechanism is provided on the bottom frame, front rollers are respectively provided on the left and right sides of the front end of the bottom frame, the front rollers are universal wheels, rear rollers are respectively provided on the left and right sides of the tail end of the bottom frame, and the rear rollers are directional wheels, and supporting parts are respectively vertically provided on the left and right sides of the tail end of the bottom frame, a brake arm located in front of the rear roller is rotatably provided on the outer side of the supporting part, a linkage shaft extending toward the supporting part is provided on the top of the brake arm, a waist-shaped hole is provided on the supporting part for allowing the linkage shaft to pass through, a cam located above the linkage shaft is rotatably provided on the inner side of the supporting part, and the cam is connected to the lifting mechanism, and elastic parts are respectively connected to the left and right sides of the bottom frame, and the tail end of the elastic part is connected to the bottom of the brake arm, and the elastic part keeps the bottom of the brake arm separated from the rear roller; when the lifting mechanism is lifted, it drives the cam to rotate, and the cam pushes the linkage shaft forward so that the bottom of the brake arm is against the rear roller.

[0005] Further preferably, the waist-shaped hole is arc-shaped to adapt to the trajectory of the linkage shaft moving with the brake arm, and a clamping wheel is provided at the bottom of the brake arm. The clamping wheel is made of rubber, and the elastic member is a tension spring; when the brake arm abuts against the rear roller through the clamping wheel, the rear roller can be braked more effectively.

[0006] The cam is fixedly connected to the left and right sides of the bottom frame by a movable frame, and the movable frame is connected to the bottom frame by a movable frame.

[0007] The top support rod is further preferably provided above the support rod, the front end of the top support rod is provided with a footrest telescopic assembly, the middle part of the top support rod is provided with a first fixing rod extending downwardly, the bottom of the first fixing rod is movably connected with a driving rod, the front end of the driving rod is connected to the footrest telescopic assembly, the top push rod is arranged between the left and right driving rods, the push rod end of the first electric push rod is movably connected to the rear side frame of the bottom frame, the tail end of the guide sleeve of the first electric push rod is provided with a push plate, the two ends of a rotating crankshaft are respectively passed through the left and right supporting parts, the left and right brake arms are respectively fixed at the two ends of the rotating crankshaft, the first electric push rod drives the driving rod to swing, thereby driving the footrest telescopic assembly to extend or contract; when the first electric push rod drives the footrest telescopic assembly to extend, the push plate pushes the eccentric shaft section of the rotating crankshaft to rotate the rotating crankshaft, so that the bottom of the brake arm is against the rear roller.

[0008] Further preferably, a first rocker is movably connected to the fixed rod, an end of the first rocker away from the fixed rod is movably connected to the front end of the top support rod, the tail end of the top support rod is movably connected to the second rocker, the middle part of the second rocker is rotatably arranged on the outside of the tail end of the support rod, the bottom of the second rocker is movably connected to a driving arm, and the front end of the driving arm is connected to the telescopic assembly of the footrest; when the telescopic assembly of the footrest is extended, the top support rod is driven to tilt forward to realize the user's body leaning back.

[0009] Further preferably, the footrest telescopic assembly includes a front swing arm and a rear swing arm movably connected to the front end of the top support rod, the middle part of the rear swing arm is movably connected with a pull rod, the end of the pull rod away from the rear swing arm is movably connected to the front end of the driving rod, the front swing arm is movably connected to the front support rod at one end away from the top support rod, the middle part of the front swing arm is rotatably provided with a rear support rod, the bottom of the rear support rod is movably connected to the end of the rear swing arm away from the top support rod, the front end of the driving arm is movably connected to the rear swing arm, the top of the rear support rod is movably connected to a foot support rod, and the other end of the foot support rod is movably connected to the top of the front support rod; the footrest telescopic assembly can lift the user's legs and feet when extended, and can drop the user's legs and feet when contracted.

[0010] Further preferably, a backrest assembly is provided at the tail end of the top support rod, and the backrest assembly includes a second fixed rod which is arranged at the tail end of the top support rod and extends upward, the top of the second fixed rod is movably connected with a backrest connecting rod, a backrest cross support rod is provided between the left and right backrest connecting rods, a second electric push rod is movably connected below the backrest cross support rod, and the front end of the second electric push rod is movably connected below the top push rod; the backrest connecting rod can realize the user's back vertical when it is in a vertical state, and can realize the user's back lying flat when it is in a reclining state.

[0011] A working method of the seat frame comprises the following steps: 1) In the initial state, the lifting mechanism is in a sinking state, the footrest telescopic assembly is in a contracted state, the backrest connecting rod is in a vertical state, and the elastic member keeps the bottom of the brake arm and the rear roller separated. At this time, the user's legs and feet can fall down and the back can be in a vertical state (i.e., sitting upright), and the seat can be moved by the rollers in this state; 2) The first electric push rod contracts to drive the driving rod to swing downward, driving the footrest telescopic assembly to extend. During the extension process, the footrest telescopic assembly drives the top support rod to tilt forward. When the push plate pushes the rotating crankshaft to rotate so that the bottom of the brake arm abuts against the rear roller, the first electric push rod stops contracting. At this time, the user can lean back with his legs and feet raised (i.e., the upward sitting posture). In this state, the seat cannot be moved by the rollers; 3) The second electric push rod drives the backrest connecting rod to swing backward, and the user's back can be placed in a lying position (i.e., lying posture); 4) The first electric push rod extends to drive the driving rod to swing upward, driving the footrest telescopic assembly to retract, and the second electric push rod drives the backrest connecting rod to swing forward to a vertical state, at which time the seat returns to its initial state; 5) The first electric push rod continues to extend to drive the lifting mechanism to lift. The lifting mechanism lifts the top support rod to rise and tilt backward. When the lifting mechanism lifts, it drives the cam to rotate. The cam pushes the linkage shaft forward to make the bottom of the brake arm collide with the rear roller. At this time, the user's body can lean forward and the height can be increased. In this state, the seat cannot be moved by the rollers, and the user can stand up safely from the seat.

[0012] The beneficial effects of the present invention are as follows: when working, the elastic member keeps the bottom of the brake arm and the rear roller separated; when the lifting mechanism is lifted, it drives the cam to rotate, and the cam pushes the linkage shaft forward to make the bottom of the brake arm collide with the rear roller. At this time, the seat frame cannot move through the roller to achieve a self-locking effect; therefore, the seat frame can enable the seat to achieve self-locking when lifted, and the user can stand up safely from the seat. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to clearly illustrate the innovative principle of the invention and its advantages over existing seat frames, possible embodiments are described below by means of non-limiting examples of the application of said principle with the aid of the accompanying drawings. In the drawings: Figure 1 A three-dimensional diagram of the lifting mechanism of the seat frame of the present invention in a lifted state; Figure 2 for Figure 1 The main view of Figure 3 for Figure 1 Exploded diagram of Figure 4 for Figure 3 A partial enlarged view of point A; Figure 5 is a stereoscopic diagram of the footrest telescopic assembly in an extended state; Figure 6 is a stereoscopic diagram of the footrest telescopic assembly in a retracted state; Figure 7 A three-dimensional diagram of the seat frame of the present invention in an upright sitting state; Figure 8 for Figure 7 The main view of Fig. 9 A three-dimensional diagram of the seat frame of the present invention in a reclining sitting position; Fig.10 for Fig. 9 The main view of Fig.11 A three-dimensional diagram of the seat frame of the present invention in a lying state; Fig.12 for Fig.11 The main view of Fig.13A three-dimensional diagram of the lifting mechanism of the seat frame of the present invention in a lifted state; Fig.14 A three-dimensional diagram of the lifting mechanism of the seat frame of the present invention in a lifted state; Fig.15 for Fig.13 main view. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0015] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without making any creative work shall fall within the scope of protection of the present invention.

[0016] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0017] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances. Example

[0018] like Figure 1-15A seat frame, comprising a bottom frame 1, a lifting mechanism is provided on the bottom frame 1, front rollers 2 are provided on the left and right sides of the front end of the bottom frame 1, the front rollers 2 are universal wheels, rear rollers 3 are provided on the left and right sides of the tail end of the bottom frame 1, the rear rollers 3 are directional wheels, and support parts 4 are vertically provided on the left and right sides of the tail end of the bottom frame 1, a brake arm 5 located in front of the rear roller 3 is rotatably provided on the outer side of the support part 4, a linkage shaft 6 extending toward the support part 4 is provided on the top of the brake arm 5, and the support part 4 is provided with a waist-shaped hole 7 for allowing the linkage shaft 6 to pass through, and a cam 8 located above the linkage shaft 6 is rotatably provided on the inner side of the support portion 4, and the cam 8 is connected to the lifting mechanism. The left and right sides of the bottom frame 1 are respectively connected with elastic members 9, and the tail ends of the elastic members 9 are connected to the bottom of the brake arm 5, and the elastic members 9 keep the bottom of the brake arm 5 and the rear roller 3 separated; when the lifting mechanism is lifted, the cam 8 is driven to rotate, and the cam 8 pushes the linkage shaft 6 forward to make the bottom of the brake arm 5 abut against the rear roller 3.

[0019] Preferably, the waist-shaped hole 7 is arc-shaped to adapt to the trajectory of the linkage shaft 6 moving with the brake arm 5. A clamping wheel 10 is provided at the bottom of the brake arm 5. The clamping wheel 10 is made of rubber, and the elastic member 9 is a tension spring. When the brake arm 5 abuts against the rear roller 3 through the clamping wheel 10, the rear roller 3 can be braked more effectively.

[0020] Preferably, the lifting mechanism includes a pair of support rods 11, which are symmetrically arranged above the left and right sides of the bottom frame 1. The front end of the support rod 11 is provided with a fixing rod 12 extending downward, and the bottom of the fixing rod 12 is movably connected to a rear rocker 13, and the end of the rear rocker 13 away from the fixing rod 12 is fixedly connected to the cam 8. The middle part of the rear rocker 13 is provided with a connecting rod 14 extending upward, and the end of the connecting rod 14 away from the rear rocker 13 is provided with a rotating rod 15, and the front end of the rotating rod 15 is movably connected to a front rocker 16, and the front rocker 16 One end away from the rotating rod 15 is movably connected to the bottom frame 1, and the tail end of the rotating rod 15 is movably connected to the rear swing rod 17. One end of the rear swing rod 17 away from the rotating rod 15 is movably connected to the tail end of the support rod 11, and a push rod 18 is arranged between the front ends of the left and right support rods 11. A first electric push rod 19 is movably connected below the push rod 18, and one end of the first electric push rod 19 away from the push rod 18 is movably connected to the rear side frame of the bottom frame 1; when the lifting mechanism is lifted, the support rod 11 can be lifted and tilted backward, so that the user can stand up from the seat more easily.

[0021] Preferably, a top support rod 20 is provided above the support rod 11, and a footrest telescopic assembly is provided at the front end of the top support rod 20, and a first fixing rod 39 extending downward is provided in the middle of the top support rod 20, and a driving rod 21 is movably connected to the bottom of the first fixing rod 39, and the front end of the driving rod 21 is connected to the footrest telescopic assembly, and the top push rod 18 is provided between the left and right driving rods 21, and the push rod end 22 of the first electric push rod 19 is movably connected to the rear side frame of the bottom frame 1, and the first electric push rod 1 A push plate 24 is provided at the rear end of the guide sleeve 23 of 9, and two ends of a rotating crankshaft 25 are respectively passed through the left and right supporting parts 4, and the left and right brake arms 5 are respectively fixed at the two ends of the rotating crankshaft 25. The first electric push rod 19 drives the driving rod 21 to swing, thereby driving the footrest telescopic assembly to extend or contract; when the first electric push rod 19 drives the footrest telescopic assembly to extend, the push plate 24 pushes the eccentric shaft section of the rotating crankshaft 25 to rotate the rotating crankshaft 25, so that the bottom of the brake arm 5 is against the rear roller 3.

[0022] Preferably, the fixing rod 12 is movably connected with a first rocker arm 26, one end of the first rocker arm 26 away from the fixing rod 12 is movably connected to the front end of the top support rod 20, the tail end of the top support rod 20 is movably connected with a second rocker arm 27, the middle part of the second rocker arm 27 is rotatably arranged on the outside of the tail end of the support rod 11, the bottom of the second rocker arm 27 is movably connected with a driving arm 28, and the front end of the driving arm 28 is connected to the telescopic assembly of the footrest; when the telescopic assembly of the footrest is extended, the top support rod 20 is driven to tilt forward to realize the user's body leaning back.

[0023] Preferably, the footrest telescopic assembly includes a front swing arm 29 and a rear swing arm 30 movably connected to the front end of the top support rod 20, the middle part of the rear swing arm 30 is movably connected with a pull rod 31, the end of the pull rod 31 away from the rear swing arm 30 is movably connected to the front end of the driving rod 21, the front swing arm 29 is movably connected to the front support rod 32 at one end away from the top support rod 20, the middle part of the front swing arm 29 is rotatably provided with a rear support rod 33, the bottom of the rear support rod 33 is movably connected to the end of the rear swing arm 30 away from the top support rod 20, the front end of the driving arm 28 is movably connected to the rear swing arm 30, the top of the rear support rod 33 is movably connected to a foot support rod 34, and the other end of the foot support rod 34 is movably connected to the top of the front support rod 32; the footrest telescopic assembly can lift the user's legs and feet when extended, and can drop the user's legs and feet when contracted.

[0024] Preferably, Figure 13-14A backrest assembly is provided at the tail end of the top support rod 20, and the backrest assembly includes a second fixed rod 38 which is arranged at the tail end of the top support rod 20 and extends upward, and a backrest connecting rod 35 is movably connected to the top of the second fixed rod 38, and a backrest cross support rod 36 is provided between the left and right backrest connecting rods 35, and a second electric push rod 37 is movably connected to the bottom of the backrest cross support rod 36, and the front end of the second electric push rod 37 is movably connected to the bottom of the top push rod 18; the backrest connecting rod 35 can realize the user's back vertical when it is in a vertical state, and can realize the user's back lying flat when the backrest connecting rod 35 is in a reclining state. Example

[0025] A working method of the seat frame according to embodiment 1 comprises the following steps: 1) If Figure 7-8 In the initial state, the lifting mechanism is in a sinking state, the footrest telescopic assembly is in a contracted state, the backrest connecting rod 35 is in a vertical state, and the elastic member 9 keeps the bottom of the brake arm 5 and the rear roller 3 separated. At this time, the user's legs and feet can fall down and the back can be in a vertical state (i.e., sitting upright), and the seat can be moved by the rollers in this state; 2) If Figure 9-10 , the first electric push rod 19 contracts to drive the driving rod 21 to swing downward, driving the footrest telescopic assembly to extend. During the extension process, the footrest telescopic assembly drives the top support rod 20 to tilt forward. When the push plate 24 pushes the rotating crankshaft 25 to rotate so that the bottom of the brake arm 5 abuts against the rear roller 3, the first electric push rod 19 stops contracting. At this time, the user's body can be tilted back with the legs and feet raised (i.e., the upward sitting posture). In this state, the seat cannot be moved by the rollers; 3) If Figure 11-12 , the second electric push rod 37 drives the backrest connecting rod 35 to swing backward, at which time the user's back can be placed in a flat lying state (i.e., lying position); 4) The first electric push rod 19 extends to drive the driving rod 21 to swing upward, driving the footrest telescopic assembly to retract, and the second electric push rod 37 drives the backrest connecting rod 35 to swing forward to a vertical state, at which time the seat returns to its initial state; 5) If Figure 13-15 , the first electric push rod 19 continues to extend to drive the lifting mechanism to lift, and the lifting mechanism lifts the top support rod 20 to rise and tilt backward. When the lifting mechanism lifts, it drives the cam 8 to rotate, and the cam 8 pushes the linkage shaft 6 forward to make the bottom of the brake arm 5 abut against the rear roller 3. At this time, the user's body can lean forward and the height can be increased. In this state, the seat cannot be moved by the rollers, and the user can stand up safely from the seat.

[0026] During operation, the elastic member 9 keeps the bottom of the brake arm 5 separated from the rear roller 3; when the lifting mechanism is lifted, the cam 8 is driven to rotate, and the cam 8 pushes the linkage shaft 6 forward to make the bottom of the brake arm 5 collide with the rear roller 3. At this time, the seat frame cannot move through the roller to achieve a self-locking effect; therefore, the seat frame of this embodiment can enable the seat to achieve self-locking when lifted, and the user can stand up safely from the seat.

[0027] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A seat frame, characterized in that: The invention comprises a bottom frame (1), wherein the bottom frame (1) is provided with a lifting mechanism, wherein at least one front roller (2) is provided on the front side of the bottom frame (1), and rear rollers (3) are provided on the left and right sides of the rear end of the bottom frame (1), respectively, and support parts (4) are vertically provided on the left and right sides of the rear end of the bottom frame (1), wherein a brake arm (5) located on the front side of the rear roller (3) is rotatably provided on the outer side of the support part (4), wherein a linkage shaft (6) extending toward the support part (4) is provided on the top of the brake arm (5), and wherein a waist-shaped hole is provided on the support part (4) to allow the linkage shaft (6) to pass through. (7), a cam (8) located above the linkage shaft (6) is rotatably provided on the inner side of the support portion (4), the cam (8) is connected to the lifting mechanism, and elastic members (9) are respectively connected to the left and right sides of the bottom frame (1), the tail end of the elastic member (9) is connected to the bottom of the brake arm (5), and the elastic member (9) keeps the bottom of the brake arm (5) and the rear roller (3) separated; when the lifting mechanism is lifted, the cam (8) is driven to rotate, and the cam (8) pushes the linkage shaft (6) forward so that the bottom of the brake arm (5) is against the rear roller (3).

2. The seat frame according to claim 1, characterized in that: The waist-shaped hole (7) is arc-shaped to adapt to the trajectory of the linkage shaft (6) moving with the brake arm (5); a clamping wheel (10) is provided at the bottom of the brake arm (5); and the elastic member (9) is a tension spring.

3. The seat frame according to claim 1, characterized in that: The lifting mechanism comprises a pair of support rods (11), the pair of support rods (11) are symmetrically arranged above the left and right sides of the bottom frame (1), the front ends of the support rods (11) are provided with downwardly extending fixing rods (12), the bottom of the fixing rods (12) is movably connected with a rear rocker (13), one end of the rear rocker (13) away from the fixing rod (12) is fixedly connected to the cam (8), the middle part of the rear rocker (13) is provided with a connecting rod (14) extending upward, the end of the connecting rod (14) away from the rear rocker (13) is provided with a rotating rod (15), the front end of the rotating rod (15) is movably connected to the rear rocker (13), and the rear rocker (15) is provided with a rotating rod (15). A front rocker (16) is connected, and one end of the front rocker (16) away from the rotating rod (15) is movably connected to the bottom frame (1), and the tail end of the rotating rod (15) is movably connected to a rear rocker (17), and one end of the rear rocker (17) away from the rotating rod (15) is movably connected to the tail end of the support rod (11), and a push rod (18) is provided between the front ends of the left and right support rods (11), and a first electric push rod (19) is movably connected below the push rod (18), and one end of the first electric push rod (19) away from the push rod (18) is movably connected to the rear side frame of the bottom frame (1).

4. The seat frame according to claim 3, characterized in that: A top support rod (20) is arranged above the support rod (11), a footrest telescopic assembly is arranged at the front end of the top support rod (20), a first fixing rod (39) extending downward is arranged in the middle of the top support rod (20), a driving rod (21) is movably connected to the bottom of the first fixing rod (39), the front end of the driving rod (21) is connected to the footrest telescopic assembly, the top push rod (18) is arranged between the left and right driving rods (21), a push rod end (22) of the first electric push rod (19) is movably connected to the rear side frame of the bottom frame (1), and the first A push plate (24) is provided at the rear end of the guide sleeve (23) of the electric push rod (19), and two ends of a rotating crankshaft (25) are respectively passed through the left and right supporting parts (4), and the left and right brake arms (5) are respectively fixed to the two ends of the rotating crankshaft (25). The first electric push rod (19) drives the driving rod (21) to swing, thereby driving the footrest telescopic assembly to extend or retract; when the first electric push rod (19) drives the footrest telescopic assembly to extend, the push plate (24) pushes the rotating crankshaft (25) to rotate, so that the bottom of the brake arm (5) abuts against the rear roller (3).

5. The seat frame according to claim 4, characterized in that: The fixing rod (12) is movably connected to a first rocking rod (26); one end of the first rocking rod (26) away from the fixing rod (12) is movably connected to the front end of the top support rod (20); the rear end of the top support rod (20) is movably connected to a second rocking rod (27); the middle part of the second rocking rod (27) is rotatably arranged on the outside of the rear end of the support rod (11); the bottom of the second rocking rod (27) is movably connected to a driving arm (28); the front end of the driving arm (28) is connected to the footrest telescopic assembly.

6. The seat frame according to claim 4, characterized in that: The footrest telescopic assembly comprises a front swing arm (29) and a rear swing arm (30) movably connected to the front end of the top support rod (20); a pull rod (31) is movably connected to the middle of the rear swing arm (30); one end of the pull rod (31) away from the rear swing arm (30) is movably connected to the front end of the driving rod (21); one end of the front swing arm (29) away from the top support rod (20) is movably connected to the front support rod (32); a rear support rod (33) is rotatably arranged in the middle of the front swing arm (29); the bottom of the rear support rod (33) is movably connected to the end of the rear swing arm (30) away from the top support rod (20); the top of the rear support rod (33) is movably connected to a foot support rod (34); the other end of the foot support rod (34) is movably connected to the top of the front support rod (32).

7. The seat frame according to claim 5, characterized in that: A backrest assembly is provided at the rear end of the top support rod (20), and the backrest assembly includes a second fixed rod (38) provided at the rear end of the top support rod (20) and extending upward, the top of the second fixed rod (38) is movably connected to a backrest connecting rod (35), a backrest cross support rod (36) is provided between the left and right backrest connecting rods (35), a second electric push rod (37) is movably connected below the backrest cross support rod (36), and a front end of the second electric push rod (37) is movably connected to the bottom of the top push rod (18).

8. A method for operating the seat frame according to claim 1, comprising the following steps: 1) In the initial state, the lifting mechanism is in a lowered state, the footrest telescopic assembly is in a retracted state, the backrest connecting rod (35) is in a vertical state, and the elastic member (9) keeps the bottom of the brake arm (5) and the rear roller (3) separated, so that the user's legs and feet can fall down and the back can be in a vertical state. In this state, the seat can be moved by the rollers; 2) The first electric push rod (19) contracts to drive the driving rod (21) to swing downward, driving the footrest telescopic assembly to extend. During the extension process, the footrest telescopic assembly drives the top support rod (20) to tilt forward. When the push plate (24) pushes the rotating crankshaft (25) to rotate so that the bottom of the brake arm (5) abuts against the rear roller (3), the first electric push rod (19) stops contracting. At this time, the user's body can be tilted back with legs and feet raised. In this state, the seat cannot be moved by the rollers. 3) The second electric push rod (37) drives the backrest connecting rod (35) to swing backwards, so that the user can lie flat on his back; 4) The first electric push rod (19) extends to drive the driving rod (21) to swing upward, thereby driving the footrest telescopic assembly to retract, and the second electric push rod (37) drives the backrest connecting rod (35) to swing forward to a vertical state, at which time the seat returns to its initial state; 5) The first electric push rod (19) continues to extend to drive the lifting mechanism to lift. The lifting of the lifting mechanism causes the top support rod (20) to rise and tilt backward. When the lifting mechanism is lifted, it drives the cam (8) to rotate. The cam (8) pushes the linkage shaft (6) forward so that the bottom of the brake arm (5) is against the rear roller (3). At this time, the user's body can be tilted forward and the height can be increased. In this state, the seat cannot be moved by the rollers, and the user can stand up from the seat safely.

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