A three-adjustable chair frame

Abstract

An adjustable chair frame includes an adjustable backrest, an adjustable seat, and an adjustable leg rest. The adjustable backrest includes a back frame with two sliding wheels on each side of its lower part. The sliding wheels are fitted into Y-shaped grooves, and at least one position of the sliding wheel within the groove allows the backrest to tilt backward and rotate to a horizontal position. The adjustable seat includes a seat frame hinged to the backrest. A shaped beam is hinged to the rear extension of the seat frame, and the shaped beam connects to the moving end of a push rod I, which is hinged to the backrest. The shaped beam has a notch to prevent interference with push rod II. The adjustable leg rest includes a leg frame hinged to the seat frame. A slide rail is provided on the leg frame, and the slide rail is positioned along the center of the leg frame and the seat frame. A slider is provided on the slide rail. The slider, seat frame, and push rod III are all hinged to a bracket, which is V-shaped with an obtuse angle. This invention achieves a horizontal backrest, horizontally placed leg rest and seat cushion, and the ability for the seat cushion to rotate to a right-angled vertical position.

Description

Technical Field

[0001] This invention relates to the field of adjustable massage chair frame technology, specifically to a three-adjustable chair frame. Background Technology

[0002] Because the massage chair market is flooded with products, most massage chairs on the market currently have a fixed angle between the seat and back, and some have a flexible angle between the seat and back, but the range of angle changes is small. Users basically maintain a certain posture during the massage, and the function is limited. Therefore, in terms of their functions, especially the chair frame that they rely on to achieve horizontal placement of the backrest, leg rest and seat cushion, and seat cushion angle adjustment, they cannot achieve these rotating positions.

[0003] As seats are frequently used everyday items, regarding adjustable seating posture: currently available seats offer adjustable backrests, adjustable leg rests, and adjustable seat height; these adjustments utilize electric push rods, gas spring locking, and manual gear locking mechanisms, as seen in massage chairs where both backrest and leg rest are adjustable. Existing technology, such as a massage chair frame with adjustable seat angle (CN217286422U), discloses electric push rod adjustment of the leg rest, backrest, and seat cushion. However, its rotation method is a hinged + telescopic drive rotation, which, due to structural layout limitations, suffers from the following problems: the backrest cannot be horizontal, making it impossible to achieve horizontal placement due to the telescopic drive + hinged rotation and space constraints; the inability to achieve horizontal placement means the structure is at a dead point in the linkage mechanism, causing it to jam or exhibit uncertain movement; therefore, currently available adjustable backrests can only approach horizontality, and the leg rest and seat cushion cannot rotate to a single plane; the seat cushion is generally not adjustable for rotation.

[0004] However, if we consider pre-adjustment and eliminate the angle between the backrest and the horizontal position by rotating the overall angle, there is a problem of sacrificing the initial angle of the backrest, resulting in an excessively large initial backrest tilt angle. Alternatively, since this rotation can never make the telescopic mechanism and the backrest on the same horizontal plane, a large amount of lower space is required for the rotation formed by the telescopic drive to obtain a larger adjustable angle range.

[0005] The seat cushion cannot rotate 90 degrees, nor can it move with the backrest. Because the seat cushion is hinged to the base frame, it is generally impossible to place the telescopic mechanism that drives the seat cushion frame to rotate on the same horizontal plane as the seat cushion frame. Moreover, its telescopic end is connected to the front of the seat cushion, which is similar to the dead point of a linkage mechanism. In other words, the conventional drive is set below the seat cushion frame, and it cannot rotate to a right angle position. The seat cushion and the backrest are two independent mechanisms, which are hinged together and move independently.

[0006] Because the leg rest rotation is driven by a hinge and telescopic mechanism, with the telescopic mechanism located on the seat cushion, it is also subject to the dead point position of the linkage mechanism. This makes it impossible to avoid jamming and uncertainty in movement, resulting in the leg rest and the upper part of the seat cushion not reaching a horizontal angle or being less than a flat angle.

[0007] Existing chairs cannot be combined with yoga postures for training. Yoga postures require considerable muscle strength to perform, and existing chairs cannot be combined with yoga postures or provide auxiliary strength training. Summary of the Invention

[0008] In view of this, and in view of the shortcomings of the prior art, the purpose of the present invention is to provide a three-adjustable chair frame in which the leg rest and seat frame can be horizontal or negative angle, the seat cushion frame can be adjusted to rotate 0-90 degrees, the backrest frame can be rotated to a horizontal position, and the seat cushion frame moves and adjusts together with the backrest frame to obtain more seat postures.

[0009] This application aims to address one of the problems in the background art.

[0010] The technical solution adopted in this invention is as follows: In order to achieve the above-mentioned objectives and other related objectives, this invention provides an adjustable back frame, including a back frame, with two sliding wheels on both sides of the lower part of the back frame. The sliding wheels are fitted into Y-shaped grooves, and at least one position of the sliding wheel in the groove causes the back frame to tilt backward and rotate to a horizontal position.

[0011] The technical solution provided in this application also has the following technical features:

[0012] Preferably, the points on the projection and vertical section of the center of the pulley and the center of the hinged back frame form a triangle.

[0013] Preferably, the sliding wheels are mounted on the inverted L-shaped frame, and the short end of the inverted L-shaped frame is vertically connected to the back frame.

[0014] Preferably, the sliding wheels are located on the rear side of the back frame.

[0015] Preferably, the waist frame of the parallel back frame with sliding wheels.

[0016] Preferably, the waist frame of the planar parallel back frame is composed of the axes of the sliding wheels.

[0017] Preferably, the axis of the pulley is parallel to the axis of the hinged back frame.

[0018] Preferably, the slide is mounted on the base frame.

[0019] Preferably, one end of the push rod II of the back frame is hinged to form a rotary joint, and the moving end of the push rod II is connected to the lower end beam of the back frame.

[0020] Preferably, one end of push rod II is hinged to the base frame.

[0021] An adjustable seat frame includes a seat frame, a back frame hinged to the seat frame, and a shaped beam hinged to the rear extension end of the seat frame. The shaped beam is connected to the movable end of push rod I, which is hinged to the back frame. The shaped beam has a notch to avoid interference with push rod II.

[0022] Preferably, the notch is rectangular.

[0023] Preferably, the notch is composed of spliced ​​panels.

[0024] An adjustable leg support includes a leg frame and a hinged seat frame. The initial position angle between the upper working surfaces of the leg frame and the seat frame is greater than a straight angle but not greater than an abscissa. A slide rail is provided on the leg frame and is arranged along the center of the leg frame and the seat frame. A slider is provided on the slide rail. The slider, seat frame, and push rod III of the slide rail are all hinged to a bracket. The bracket is V-shaped and the included angle is obtuse.

[0025] The short end of the bracket is hinged to the slide rail, the long end of the bracket is hinged to the base, and push rod III is hinged to the protruding lug in the middle of the long end of the bracket; the hinge of the base is provided with a protruding lug to avoid motion interference; push rod III pushes the bracket to make the leg frame rotate relative to the base, so that the included angle between the upper working surfaces of the leg frame and the base is less than or equal to a flat angle.

[0026] A three-adjustable chair frame includes an adjustable leg rest, an adjustable seat frame, an adjustable backrest, and adjustment levers I, II, and III to adjust the chair frame from its initial normal seating posture to: V-shape, L-shape, Z-shape, 7-shape, and I-shape.

[0027] Initial normal seat posture: the moving end of push rod I is at position T0, the moving end of push rod II is at position P1, and the moving end of push rod III is at position S;

[0028] V-shaped seat posture: The moving end of push rod III is at position E, and the moving end of push rod I is at any position between T0 and T2, including positions T0 and T2, and T0 and T2 correspond to the size of the V-shaped angle; the moving end of push rod II is at different positions between P1 and P2, including positions P1 and P2, corresponding to different angles of the V-shaped seat posture and the horizontal plane.

[0029] L-shaped seat posture: The moving end of push rod I is at position T0, the moving end of push rod III is at position E, and the moving end of push rod II is at position P2; the movement of the moving end of push rod II causes the L-shaped seat posture to rotate as a whole, and the L-shaped seat posture and the horizontal plane are at different angles; the sliding of the moving end of push rod I causes the L-shaped angle of the L-shaped seat posture to be different.

[0030] Z-shaped seat posture: The moving end of push rod I is at position T0, the moving end of push rod III is at position S, and the moving end of push rod II is at position P2;

[0031] Type 7 seat posture: The moving end of push rod I is at position T1, the moving end of push rod III is at position S, and the moving end of push rod II is at position P2;

[0032] Type 1 seat posture: The moving end of push rod I is at position T1, the moving end of push rod III is at position E, and the moving end of push rod II is at position P2.

[0033] The present invention has the following beneficial effects:

[0034] 1. The rotation of the backrest frame in this invention is achieved through a non-hinged structure, relying on the cooperation of a Y-shaped groove and a sliding wheel to rotate the backrest and backrest frame. It can rotate from an initial angle to a horizontal position, meaning the rotation center of the backrest frame is not fixed, and the backrest frame also shifts laterally during rotation. Therefore, this structure requires little rotation space. Pushing the push rod II at the lower end of the backrest frame through a small-angle swing extension / retraction is sufficient to rotate the backrest frame to a horizontal position (small angle refers to less than 30°). In the structure of this application, since the lower groove has a straight trajectory, and the sliding wheel on it is close to or parallel to the hinge axis of the moving end of the push rod II of the backrest frame, it can further achieve a swing within 10°. If the sliding wheel of the lower straight trajectory coincides with the hinge axis, a swing within 5° can be achieved to rotate the backrest and backrest frame to a horizontal position. This is because the moving end of the push rod II and the sliding wheel of the lower straight trajectory have the same trajectory, thus allowing for a small-angle swing extension / retraction within 5° to complete the rotation of the backrest frame from its initial position to a horizontal position.

[0035] 2. The seat frame of the present invention is hinged to the back frame and moves with the back frame as a whole. Moreover, the adjustment and rotation mechanism of the seat frame, namely push rod I, is set on the back frame. Therefore, no matter how the back frame moves, different angles between the seat frame and the back frame can be obtained by simply adjusting push rod I.

[0036] 3. The leg frame of the present invention is hinged to the seat frame, and the leg frame moves with the seat frame as a whole. Therefore, no matter how the seat frame moves, only the push rod III needs to be adjusted to obtain different included angles between the leg frame and the seat frame. In order to achieve large angle changes between the leg frame and the seat frame, that is, to achieve a flat angle or less than a flat angle between the upper working surfaces of the seat frame and the leg frame, the bracket is set and cooperates with the slide rail and the slider of the slide rail to realize a combination of a four-bar linkage mechanism and a crank-slider mechanism, which realizes large angles between the leg frame and the seat frame, especially the posture where the included angle between the upper working surfaces of the seat frame and the leg frame is a flat angle or less than a flat angle.

[0037] 4. The leg rest, seat frame, and backrest of the present invention all have the freedom of rotation, and the relative rotation between any two of them can change the included angle. In particular, the seat frame can rotate at a certain angle; multiple postures such as "V", "L", "Z", "—", and "7" seat postures are achieved, which can be used for yoga posture training. Moreover, the push rod of the present invention can be combined with an electric push rod to realize the assisted training of human postures, without the need for excessive physical effort of the human body, reducing the training difficulty and required strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 FIG. is a perspective view of the rear side of a three-adjustable chair frame according to the present invention;

[0039] Figure 2 FIG. is a perspective view of the front side of a three-adjustable chair frame according to the present invention;

[0040] Figure 3 FIG. is an exploded view of a three-adjustable chair frame according to the present invention;

[0041] Figure 4 FIG. is a perspective view of the rear side of a three-adjustable chair frame according to the present invention;

[0042] Figure 5 FIG. is a perspective view of the rear view of a three-adjustable chair frame according to the present invention;

[0043] Figure 6 FIG. is a perspective view of the bottom view of a three-adjustable chair frame according to the present invention;

[0044] Figure 7 FIG. is a schematic diagram of the initial normal seat posture of a three-adjustable chair frame according to the present invention;

[0045] Figure 8 FIG. is a schematic diagram of the "V" seat posture of a three-adjustable chair frame according to the present invention;

[0046] Figure 9 FIG. is a schematic diagram of the "L" seat posture of a three-adjustable chair frame according to the present invention;

[0047] Figure 10 FIG. is a schematic diagram of the "Z" seat posture of a three-adjustable chair frame according to the present invention;

[0048] Figure 11 FIG. is a schematic diagram of the "7" seat posture of a three-adjustable chair frame according to the present invention;

[0049] Figure 12 FIG. is a schematic diagram of the "—" seat posture of a three-adjustable chair frame according to the present invention;

[0050] The reference numerals in the figures are explained as follows:

[0051] 10. Backrest

[0052] 20. Seat frame

[0053] 30. Leg support

[0054] 40. Base frame

[0055] 50. Bracket

[0056] 60. Push Rod I

[0057] 70. Push Rod II

[0058] 80. Push Rod III

[0059] 90. Irregularly shaped beams

[0060] 101. Pulley

[0061] 301. Slide rail

[0062] 401. Slide groove

[0063] 901. Gap. Detailed Implementation

[0064] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0065] In the description of this invention, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0066] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0067] Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0068] like Figure 1 , Figure 2 , Figure 3 An adjustable back frame includes a back frame 10, with two sliding wheels 101 on both sides of the lower part of the back frame 10. The sliding wheels 101 are fitted into Y-shaped grooves 401, and at least one position of the sliding wheel 101 in the groove 401 causes the back frame 10 to tilt backward and rotate to a horizontal position.

[0069] When implemented, this application has the following characteristics: the backrest is supported by two sliding wheels 101 and the Y-shaped sliding groove 401 of the base frame 40 through the back frame 10, and is driven by the push rod II 70 to achieve horizontal placement; the leg support 30 is supported by a four-bar linkage and a crank-slider mechanism to achieve horizontal placement with the seat cushion; the seat frame 20 of the seat cushion is supported by the push rod I 60 set on the back frame 10, and the push rod I 60 and the moving end rotate with the back frame 10, so that the included angle between the seat cushion and the backrest rotates with the back frame 10, and the seat frame 20 also rotates, thus increasing the rotation angle of the seat cushion relative to the horizontal plane;

[0070] like Figure 1 The Y-shaped trajectory formed between the sliding wheel 101 of the back frame 10 and the sliding groove 401 of the base frame 40 makes the structure more stable and allows the back frame 10 to slide forward while lying down, saving space behind the back frame 10 and making reasonable use of the space. This effectively achieves zero wall contact and saves space. In addition, the lower leg support 50 and the lower leg slide rail 301 are connected to the slider, which effectively ensures the stability of the leg frame 30.

[0071] Compared to existing technologies, which primarily rely on telescopic drives and hinged structures, horizontal placement is impossible due to the dead point of the lever. Achieving horizontal placement requires increasing the space of the base frame or sacrificing the initial angle of the backrest. A larger initial angle, equivalent to pre-rotating the entire seat to align the maximum tilt angle with the horizontal plane, still results in a large space requirement for the telescopic drive mechanism. Furthermore, the telescopic drive mechanism experiences significant swing angles during pushing, as the backrest requires nearly 70° of rotation to fold horizontally. Consequently, the swing angle of the telescopic drive mechanism varies considerably with hinged rotating drive mechanisms, typically exceeding 20° and approaching 30°. This large-angle swing also makes it difficult to utilize the space below and around the telescopic drive mechanism, and requires numerous interference avoidance designs. In contrast, this invention achieves horizontal rotation of the backrest with a small swing angle, providing ample usable space, minimizing interference, eliminating the need for extensive interference avoidance designs, and resulting in high structural utilization. It also allows for the placement of supporting electrical components.

[0072] Specifically, such as Figure 1-7The center of the sliding wheel 101 and the center of the hinged seat 20 of the back frame 10, on the projection and vertical section, form a triangle. This is because if we consider the combination of lateral movement and rotation, the back frame 10 can move and rotate, thereby achieving zero wall contact, utilizing the rear space, and increasing the rotation angle of the back frame 10. This overcomes the disadvantage that the rotation of the hinged combination telescopic drive cannot achieve a flat angle. It has no dead points and no uncertainty in motion. Through this lateral movement and rotation, the motion state is unique, and the operation is precise and reliable. The rotation angle is continuously changed through continuous displacement.

[0073] Specifically, such as Figure 1 , 2 4. The sliding wheel 101 is set on the inverted L-shaped frame, and the short end of the inverted L-shaped frame is vertically connected to the back frame 10. The sliding wheel 101 is set with the inverted L-shaped frame, which is reasonable and facilitates the design of wrapping and hiding. It is best to set it at the rear so as not to occupy the space of the equipment.

[0074] Specifically, such as Figure 1 The sliding wheels 101 are located on the rear side of the back frame 10. The sliding wheels 101 are located behind the back frame 10 because the front is equipped with sponge and the massage components need to be stored inside, so they do not take up space in the device.

[0075] Specifically, such as Figure 1 The sliding wheel 101 is parallel to the waist frame of the back frame 10, which makes it easy to control the movement trajectory of the sliding wheel 101 to form the movement trajectory of the back frame 10. This facilitates the realization of this combination of lateral movement and rotation. After rotation and lateral movement, the lateral movement is to move to the front of the seat, so the space behind can also be reduced. This is in line with ergonomics and the usual arrangement of equipment placement, that is, reserving space in front and setting it against the wall behind.

[0076] Specifically, such as Figure 1 The planar parallel back frame 10 is formed by the axis of the sliding wheel 101. Since two sliding wheels 101 are provided on each side of the back frame 10, and the sliding wheels 101 on both sides should be stacked, this structure is limited to avoid the mechanism getting stuck, so that it can obtain better movement space and smooth movement trajectory.

[0077] Specifically, such as Figure 1 The axis of the sliding wheel 101 is parallel to the axis of the hinged seat 20 of the back frame 10, making the whole structure more reasonable. That is, during the rotation of the seat 20, the rotation of the seat 20 does not interfere with the connecting equipment of the back frame 10, such as the base frame 40 and the slide 401.

[0078] Specifically, such as Figure 1 The slide 401 is set on the base frame 40 to reduce redundant parts and make the structure more compact.

[0079] Specifically, such as Figure 1One end of the push rod II 70 of the back frame 10 is hinged to form a rotating pair, and the moving end of the push rod II 70 is connected to the lower end beam of the back frame 10, reducing redundant parts and making the structure more compact.

[0080] Specifically, such as Figure 1 One end of the push rod II 70 is hinged to the base frame 40.

[0081] like Figure 1-5 An adjustable seat frame includes a seat frame 20, a back frame 10 hinged to the seat frame 20, and a shaped beam 90 hinged to the rear extension end of the seat frame 20. The shaped beam 90 is connected to the moving end of a push rod I 60, which is hinged to the back frame 10. The shaped beam 90 has a notch 901 to avoid interference with the push rod II 70. This structure provides a configuration for the seat frame 20, where the seat frame 20 is hinged to the back frame 10, and the push rod I 60 of the seat frame 20 is mounted on the back frame 10, allowing the seat frame 20 to rotate as a whole with the back frame 10. Moreover, different angles between the seat frame 20 and the back frame 10 can be achieved simply by adjusting the push rod I 60.

[0082] Specifically, such as Figure 3-5 The notch 901 is rectangular.

[0083] Specifically, such as Figure 3-5 The 901 gap is composed of spliced ​​panels.

[0084] like Figure 1-7 An adjustable leg support includes a leg frame 30, a seat frame 20 hinged to the leg frame 30, and the initial position angle between the upper working surfaces of the leg frame 30 and the seat frame 20 is greater than a straight angle and not greater than an abscissa. A slide rail 301 is provided on the leg frame 30, and the slide rail 301 is arranged along the center of the leg frame 30 and the seat frame 20. A slider is provided on the slide rail 301. The slider of the slide rail 301, the seat frame 20, and the push rod Ⅲ80 are all hinged to a bracket 50. The bracket 50 is V-shaped and the included angle is obtuse.

[0085] The short end of the bracket 50 is hinged to the slide rail 301, and the long end of the bracket 50 is hinged to the seat 20. The push rod III 80 is hinged to the protruding lug in the middle of the long end of the bracket 50. The protruding lug is provided at the hinge of the seat 20 to avoid motion interference. The push rod III 80 pushes the bracket 50 to rotate the leg 30 relative to the seat 20, so that the included angle between the upper working surfaces of the leg 30 and the seat 20 is less than or equal to a flat angle.

[0086] This structure enables large-angle leg support rotation. Relying on the crank-slider mechanism and the four-bar linkage, it forms a mechanism that can achieve large angles, such as the angle between the upper working surfaces of the leg support 30 and the seat 20 being a flat angle or less. Moreover, it overcomes the defects of traditional existing technologies that rely on a single telescopic mechanism and hinge to achieve rotational dead points, thus eliminating the uncertainty of motion.

[0087] like Figure 1-12A three-adjustable chair frame includes an adjustable leg rest, an adjustable seat frame, and an adjustable backrest frame, with adjustment levers I60, II70, and III80 to adjust the chair frame from its initial normal seating posture to: V-shape, L-shape, Z-shape, 7-shape, and I-shape.

[0088] like Figure 7 Initial normal seat posture: the moving end of push rod I 60 is at position T0, the moving end of push rod II 70 is at position P1, and the moving end of push rod III 80 is at position S;

[0089] like Figure 8 V-shaped seat posture: The moving end of push rod Ⅲ80 is at position E, the moving end of push rod Ⅰ60 is at any position between T0 and T2, including positions T0 and T2, and T0 and T2 correspond to the size of the V-shaped angle; the moving end of push rod Ⅱ70 is at different positions between P1 and P2, including positions P1 and P2, corresponding to different V-shaped seat postures and horizontal angles.

[0090] like Figure 9 L-shaped seat posture: The moving end of push rod I 60 is at position T0, the moving end of push rod III 80 is at position E, and the moving end of push rod II 70 is at position P2; the movement of the moving end of push rod II 70 causes the L-shaped seat posture to rotate as a whole, and the L-shaped seat posture and the horizontal plane are at different angles; the sliding of the moving end of push rod I 60 causes the L-shaped angle of the L-shaped seat posture to be different.

[0091] like Figure 10 Z-shaped seat posture: the moving end of push rod I 60 is at position T0, the moving end of push rod III 80 is at position S, and the moving end of push rod II 70 is at position P2;

[0092] like Figure 11 Type 7 seat posture: The moving end of push rod I 60 is in position T1, the moving end of push rod III 80 is in position S, and the moving end of push rod II 70 is in position P2;

[0093] like Figure 12 Type 1 seat posture: The moving end of push rod I 60 is at position T1, the moving end of push rod III 80 is at position E, and the moving end of push rod II 70 is at position P2;

[0094] This structure presents the process and method for adjusting the initial normal seat posture to V-type, L-type, Z-type, 7-type, and I-type seat postures.

[0095] Specifically, in general, this structure is used and implemented as follows: Figure 3Exploded structural view: Back frame 10 and base frame 20 are connected by pins; leg frame 30 and base frame 20 are connected by pins; back frame 10 is connected to base frame 40 by sliding wheel 101 and slide groove 401 on base frame 40, the sliding wheel 101 can slide on slide groove 401 to change the angle between back frame 10 and the ground or horizontal plane; one end of bracket 50 is fixed to base frame 20 by pin, and the other end is fixed to slider of slide rail 301 of leg frame 30 by pin; one end of push rod I 60 is fixed to back frame 10 by pin, and the moving end or slider of push rod I 60 is fixed to base frame 20, the slider or moving end can be at T0, T1, T2 The positional movement changes the angle between the seat frame 20 and the back frame 10; one end of the push rod II 70 of the back frame 10 is fixed to the base frame 40 by a pin, and the slider or moving end of the push rod II 70 is connected to the back frame by a pin. The slider or moving end of the push rod II 70 can move at positions P1 and P2, driving the sliding wheel 101 to slide back and forth in the slide groove 401; one end of the push rod III 80 is fixed to the seat frame 20 by a pin, and the other end is connected to the bracket 50 by a pin. The push rod III 80 drives the bracket 50 at positions E and S, and the bracket 50 drives the slider on the connecting slide rail 301 to move, thereby changing the angle between the leg frame 30 and the seat frame 20.

[0096] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. An adjustable backrest comprising a backrest (10), characterized in that, The lower part of the back frame (10) is provided with two sliding wheels (101), which are matched with the Y-shaped sliding groove (401), and the sliding wheels (101) are rotated to be horizontal at least at one position in the sliding groove (401); The center of the sliding wheel (101), the center of the hinge seat frame (20) of the back frame (10), and the point on the projection or vertical section form a triangle; The sliding wheel (101) is arranged on the inverted L-shaped frame, and the short end of the inverted L-shaped frame is vertically connected with the back frame (10); The sliding wheel (101) is arranged on the back side of the back frame (10); and the sliding wheel (101) is parallel to the waist frame of the back frame (10); The axis of the sliding wheel (101) forms a plane parallel to the waist frame of the back frame (10); and the axis of the sliding wheel (101) is parallel to the axis of the hinge seat frame (20) of the back frame (10); The sliding groove (401) is arranged on the base frame (40); and one end of the push rod II (70) is hingedly connected with the base frame (40); The one end of the push rod II (70) of the back frame (10) is hingedly and limitingly arranged to form a rotating pair; the moving end of the push rod II (70) is connected with the lower end beam of the back frame (10); the axis of the sliding wheel (101) at the lower end of the back frame coincides with the axis of the rotating pair at the moving end of the push rod II (70); the push rod II (70) at the lower end of the back frame is stretched and contracted through swinging within 5°, so that the back frame is rotated from the initial position to be horizontal.

2. An adjustable seat frame comprising a seat frame (20) hingedly connected to an adjustable back frame according to claim 1, characterized in that The extending end of the backrest of the seat frame (20) is hingedly connected with the special-shaped beam (90); the special-shaped beam (90) is connected with the moving end of the push rod I (60); the push rod I (60) is hingedly connected with the back frame (10); the special-shaped beam (90) is provided with an opening (901); and the opening (901) is used for avoiding interference with the push rod II (70).

3. An adjustable leg rest comprising a leg rest (30) hinged to an adjustable seat rest (20) as claimed in claim 2, the initial position of the upper working surfaces of the leg rest (30) and seat rest (20) being at an angle greater than a straight angle and not greater than an obtuse angle, characterized in that, The leg frame (30) is provided with a sliding rail (301), which is arranged along the center of the leg frame (30) and the seat frame (20); the sliding rail (301) is provided with a sliding block; the sliding block of the sliding rail (301), the seat frame (20), and the push rod III (80) are hingedly connected with the support (50); and the support (50) is V-shaped and has an obtuse angle. The short end of the support (50) is hingedly connected with the sliding rail (301); the long end of the support (50) is hingedly connected with the seat frame (20); the push rod III (80) is hingedly connected with the protruding lug at the middle of the long end of the support (50); the hinge connection part of the seat frame (20) is provided with a protruding lug to avoid movement interference; and the push rod III (80) pushes the support (50) to rotate the leg frame (30) relative to the seat frame (20), so that the included angle of the upper working surfaces of the leg frame (30) and the seat frame (20) is less than or equal to a straight angle.

4. A three-adjustment chair frame, characterized by The adjustable leg support, the adjustable seat frame, and the adjustable back frame are applied to adjust the push rod I (60), the push rod II (70), and the push rod III (80), so that the chair frame is adjusted from the initial normal seat posture to a V-shaped posture, an L-shaped posture, a Z-shaped posture, a 7-shaped posture, and a 1-shaped posture. Initial normal seat posture: the moving end of the push rod I (60) is at T0 position, the moving end of the push rod II (70) is at P1 position, and the moving end of the push rod III (80) is at S position; V-shaped seat posture: the moving end of the push rod III (80) is at E position, the moving end of the push rod I (60) is at any position between T0 and T2, including T0 and T2 positions, and T0 and T2 correspond to the size of the V-shaped angle; the moving end of the push rod II (70) is at different positions between P1 and P2, including P1 and P2 positions, corresponding to different angles between the V-shaped seat posture and the horizontal plane; L-shaped seat posture: the moving end of the push rod I (60) is at T0 position, the moving end of the push rod III (80) is at E position, and the moving end of the push rod II (70) is at P2 position; the movement of the moving end of the push rod II (70) makes the L-shaped seat posture rotate as a whole, and the L-shaped seat posture and the horizontal plane are at different angles; the sliding of the moving end of the push rod I (60) makes the angle of the L-shaped seat posture different; Z-shaped seat posture: the moving end of the push rod I (60) is at T0 position, the moving end of the push rod III (80) is at S position, and the moving end of the push rod II (70) is at P2 position; 7-shaped seat posture: the moving end of the push rod I (60) is at T1 position, the moving end of the push rod III (80) is at S position, and the moving end of the push rod II (70) is at P2 position; 1-shaped seat posture: the moving end of the push rod I (60) is at T1 position, the moving end of the push rod III (80) is at E position, and the moving end of the push rod II (70) is at P2 position.

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