Folding wheelchair

Abstract

The invention discloses a folding wheelchair which comprises a first four-bar linkage assembly and a second four-bar linkage assembly. The first four-bar linkage assembly comprises a front support, a backrest assembly, a rear support, a front pull rod and a rear pull rod which form a hinge point A, a hinge point B, a hinge point C and a hinge point D after being hinged, and the position relation among the hinge points meets the condition that AB: BC: CD: DA = 1: (0.8-1.05): (2.08-8.48): (1.76-8.39); the second four-connecting-rod assembly comprises a front support, a seat cushion supporting rod, a seat cushion and a backrest assembly which form a hinge point E, a hinge point F, a hinge point G and a hinge point A after being hinged, the position relation among the hinge points meets the condition that EF: FG: GA: AE = (2.59-16.3): (4.86-20.4): 1: (3.02-5.19), and the hinge point A is located below the center face of the seat cushion. The folding wheelchair is short after being folded.

Description

Technical Field

[0001] The present application relates to the technical field of medical devices, and in particular to a folding wheelchair. Background Art

[0002] A folding wheelchair is an auxiliary tool that can help people with limited mobility to move. With the development of technology, folding wheelchairs have been widely used in people's lives. In the prior art, a first four-link assembly and a second four-link assembly are provided in the folding wheelchair. When the first four-link assembly moves, the second four-link assembly moves, so that the folding wheelchair switches between an unfolded state and a folded state.

[0003] However, in the prior art, the foldable wheelchair is relatively long after being folded, which brings a poor user experience. Summary of the invention

[0004] The purpose of the present application is to provide a foldable wheelchair, which has a shorter length after being folded, thereby improving the user experience.

[0005] The embodiment of the present application is implemented as follows: The present application provides a folding wheelchair, which includes a first four-link assembly and a second four-link assembly; wherein the first four-link assembly includes a front support, a backrest assembly, a rear support and front and rear pull rods which are hinged in sequence, and the front support, the backrest assembly, the rear support and the front and rear pull rods are hinged to form a hinge point A, a hinge point B, a hinge point C and a hinge point D, and the positional relationship between the hinge points satisfies AB:BC:CD:DA=1:(0.8~1.05):(2.08~8.48):(1.76~8.39); the second four-link assembly includes It includes a front support, a seat cushion support rod, a seat cushion and a backrest assembly which are hinged in sequence. After being hinged, the front support, the seat cushion support rod, the seat cushion and the backrest assembly are hinged to form hinge point E, hinge point F, hinge point G and hinge point A, and the positional relationship between the hinge points satisfies EF:FG:GA:AE=(2.59~16.3):(4.86~20.4):1:(3.02~5.19); hinge point G and hinge point F are located on the center plane of the seat cushion, and hinge point A, hinge point B, hinge point C, hinge point D and hinge point E are located below the center plane of the seat cushion.

[0006] The beneficial effects of this application compared with the prior art are: In the folding wheelchair of the present application, the front support and the backrest assembly are hinged to form a hinge point A, the backrest assembly and the rear support are hinged to form a hinge point B, one end of the front and rear pull rods are hinged to the rear support to form a hinge point C, and the other end of the front and rear pull rods are hinged to the front support to form a hinge point D; the hinge point A is located below the center plane of the seat cushion, and the positional relationship between the hinge point A, the hinge point B, the hinge point C and the hinge point D satisfies AB:BC:CD:DA=1:(0.8~1.05):(2.08~8.48):(1.76~8.39). When the above hinge points meet this relationship, the folding wheelchair is shorter after folding, which improves the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0008] Figure 1 This is a schematic diagram of the folding wheelchair shown in the present application in an unfolded state; Figure 2 A partial exploded schematic diagram of the folding wheelchair shown in the present application; Figure 3 For this application Figure 1 The corresponding structural diagram; Figure 4 For this application Figure 3 Explosion diagram of Figure 5 This is a schematic diagram of a foldable wheelchair in a folded state shown in the present application; Figure 6 This is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly shown in the present application have a first proportional relationship; Figure 7 for Figure 6 The corresponding schematic diagram of the folding wheelchair after folding; Figure 8 This is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly shown in the present application have a second proportional relationship; Fig. 9 for Figure 8 The corresponding schematic diagram of the folding wheelchair after folding; Fig.10 This is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly shown in the present application have a third proportional relationship; Fig.11 for Fig.10 The corresponding schematic diagram of the folding wheelchair after folding; Fig.12 It is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly in the prior art have a first target proportional relationship; Fig.13 for Fig.12 The corresponding schematic diagram of the folding wheelchair after folding; Fig.14 It is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly in the prior art have a second target proportional relationship; Fig.15 for Fig.14 The corresponding schematic diagram of the folding wheelchair after folding; Fig.16 It is a schematic diagram of a case where the positions of the hinge points in the first four-link assembly in the prior art have a third target proportional relationship; Fig.17 for Fig.16 The corresponding schematic diagram of the folding wheelchair after folding; Fig.18 A partial exploded schematic diagram of a backrest assembly shown in the present application; Fig.19 This is a schematic diagram of the structure of the locking component shown in this application; Fig. 20 This is a schematic diagram of the structure of the fixing component shown in this application Figure 1 ; Fig.21 The first matching piece and the second matching piece shown in this application are shown in FIG. Figure 1 ; Fig. 22 The first matching piece and the second matching piece shown in this application are shown in FIG. Figure 2 ; Fig.23 for Fig.18 A partial enlarged schematic diagram of V1 in the middle; Fig.24 This is a schematic diagram of the structure of the fixing component shown in this application Figure 2 ; Fig.25 An exploded schematic diagram of the locking component shown in the present application; Fig.26 The rotation diagram of the backrest component shown in this application Figure 1 ; Fig. 27 The rotation diagram of the backrest component shown in this application Figure 2 ; Fig.28 The rotation diagram of the backrest component shown in this application Figure 3 ; Fig.29 The back view of the backrest component shown in this application Figure 1; Fig.30 for Fig.29 A partial enlarged schematic diagram of V2 in the middle; Fig.31 The back view of the backrest component shown in this application Figure 2 ; Fig.32 for Fig.31 A local enlarged schematic diagram of V3 in the middle.

[0009] Reference numerals: 10-folding wheelchair; 100-front support; 101-front wheel; 200-backrest assembly; 201-backrest component; 202-fixing component; 203-locking component; 204-first elastic element; 205-second elastic element; 206-handle; 207-slide; 208-rotating axis; 300-rear support; 301-rear wheel; 400-front and rear pull rods; 500-seat support rod; 600-seat cushion; 701-headrest; 702-rod; 801-adjusting component; 802-adjusting pin; 803-third elastic element; 804-fourth elastic element; 2011-first protrusion; 2012-installation groove ;2013-second protrusion;2021-third limiting surface;2022-fourth limiting surface;2023-accommodating groove;2024-fifth end surface;2031-first end surface;2032-second end surface;2033-connecting shaft;2034-second clamping plane;7021-adjusting hole;8011-body;8012-adjusting rod;8013-fixing rod;8021-inclined hole;20111-accommodating groove;20112-third end surface;20113-fourth end surface;20114-first clamping plane;20121-first limiting surface;20122-second limiting surface;80211-inclined surface. DETAILED DESCRIPTION

[0010] The terms “first”, “second”, “third”, etc. are only used for distinguishing descriptions and do not indicate the order of arrangement, nor can they be understood as indicating or implying relative importance.

[0011] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0012] In the description of the present application, it should be noted that the terms "inside", "outside", "left", "right", "up", "down", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings, or are directions or positional relationships in which the products of the present application are usually placed when in use. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0013] In the description of this application, unless otherwise clearly specified and limited, the terms "set", "installed", "connected" and "connected" should be understood in a broad sense. For example, it 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, and it can be the internal connection of two elements.

[0014] In the prior art, the folding wheelchair is relatively long after folding, which makes the folding wheelchair occupy a larger area after folding when the width is the same, giving the user a poor user experience. In order to solve the above technical problems, the present application provides a folding wheelchair, which is relatively short after folding, greatly shortening the area occupied by the wheelchair after folding. The technical solution of the folding wheelchair in the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0015] like Figure 1-Figure 4As shown, the folding wheelchair 10 in the embodiment of the present application includes a first four-bar linkage assembly and a second four-bar linkage assembly; the first four-bar linkage assembly includes a front support 100, a backrest assembly 200, a rear support 300 and a front and rear pull rod 400 which are hinged in sequence; the second four-bar linkage assembly includes a front support 100, a seat cushion support rod 500, a seat cushion 600 and a backrest assembly 200 which are hinged in sequence. In the first four-bar linkage assembly, the front support 100, the backrest assembly 200, the rear support 300 and the front and rear pull rod 400 are hinged to form a hinge point A, a hinge point B, a hinge point C and a hinge point D; in the second four-bar linkage assembly, the front support 100, the seat cushion support rod 500, the seat cushion 600 and the backrest assembly 200 are hinged to form a hinge point E, a hinge point F, a hinge point G and a hinge point A. Specifically, the folding wheelchair 10 has a front wheel 101 and a rear wheel 301, and the front wheel 101 and the rear wheel 301 are used to contact with the placement surface of the folding wheelchair 10 to support the folding wheelchair 10, one end of the front support 100 is used to install the front wheel 101 of the folding wheelchair 10, and the other end of the front support 100 is hinged with the backrest assembly 200 to form a hinge point A; one end of the rear support 300 is used to install the rear wheel 301 of the folding wheelchair 10, and the other end of the rear support 300 is hinged with the backrest assembly 200 to form a hinge point A. Part 200 is hinged to form a hinge point B; one end of the front and rear pull rod 400 is hinged to the rear support 300 to form a hinge point C, and the other end of the front and rear pull rod 400 is hinged to the front support 100 to form a hinge point D; one end of the seat cushion support rod 500 is hinged to the front support 100 to form a hinge point E, the other end of the seat cushion support rod 500 is hinged to the seat cushion 600 to form a hinge point F, and the end of the seat cushion 600 away from the hinge point F is hinged to the backrest assembly 200 to form a hinge point G.

[0016] During an operation, when the folding wheelchair 10 is in a state such as Figure 1 In the expanded state shown, the user can push the backrest assembly 200 to move the backrest assembly 200 toward Figure 1 The backrest assembly 200 rotates in the first direction S1, and the first four-bar linkage assembly moves; the first four-bar linkage assembly moves while driving the second four-bar linkage assembly to move; when the first four-bar linkage assembly and the second four-bar linkage assembly move to the specified position, the folding wheelchair 10 is transformed into Figure 5 Shown in folded state.

[0017] During an operation, when the folding wheelchair 10 is in a state such as Figure 5 In the folded state shown, the user can pull the backrest assembly 200 to move the backrest assembly 200 toward Figure 5 The backrest assembly 200 rotates in the second direction S2, and the first four-bar linkage assembly moves; the first four-bar linkage assembly moves while driving the second four-bar linkage assembly to move; when the first four-bar linkage assembly and the second four-bar linkage assembly move to the specified position, the folding wheelchair 10 is transformed into Figure 1Shown in expanded state.

[0018] The applicant has found that the length ratio relationship of the straight line formed by each hinge point in the first four-bar linkage assembly and the position relationship between each hinge point in the first four-bar linkage assembly will affect the length and volume of the foldable wheelchair 10 after folding, which is specifically described below: In the embodiment of the present application, in the first four-link assembly, hinge point A, hinge point B, hinge point C and hinge point D are all located below the center plane of the seat cushion 600. The positional relationship between hinge point A, hinge point B, hinge point C and hinge point D satisfies AB:BC:CD:DA=1:(0.8~1.05):(2.08~8.48):(1.76~8.39); wherein AB is the straight line formed by hinge point A and hinge point B, BC is the straight line formed by hinge point B and hinge point C, CD is the straight line formed by hinge point C and hinge point D, and DA is the straight line formed by hinge point D and hinge point A; the above positional relationship represents the length relationship between the straight lines.

[0019] In the prior art, the positional relationship between the hinge points in the first four-link assembly is: AB: BC: CD: DA = 1: (1.1~1.2): (2.35~3.8): (2.4~3.9); and in the prior art, hinge point A is usually set above the center plane of the seat cushion 600, and hinge point B, hinge point C, and hinge point D are set below the seat cushion 600.

[0020] 1. When the positional relationship between the hinge points in the first four-link assembly of the folding wheelchair 10 and the length ratio relationship of the straight line formed by the hinge points are the same as those in the embodiment of the present application, the applicant finds that: (1) When AB:BC:CD:DA=1:1.05:8.48:8.39, Figure 6 As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Figure 7 As shown, the height of the foldable wheelchair 10 in the folded state is 299 mm, and the length of the foldable wheelchair 10 is 649 mm.

[0021] (2) When AB:BC:CD:DA=1:0.9:3.24:3.02, Figure 8 As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Fig. 9 As shown, the height of the foldable wheelchair 10 in the folded state is 299 mm, and the length of the foldable wheelchair 10 is 649 mm.

[0022] (3) When AB:BC:CD:DA=1:0.8:2.08:1.76, Fig.10As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Fig.11 As shown, the height of the foldable wheelchair 10 in the folded state is 297 mm, and the length of the foldable wheelchair 10 is 659 mm.

[0023] 2. When the positional relationship between the hinge points in the first four-link assembly of the folding wheelchair 10 and the length ratio relationship of the straight line formed by the hinge points are the same as those in the prior art, the applicant found that: (1) When AB:BC:CD:DA=1:1.1:2.35:2.4, Fig.12 As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Fig.13 As shown, the height of the foldable wheelchair 10 in the folded state is 304 mm, and the length of the foldable wheelchair 10 is 699 mm.

[0024] (2) When AB:BC:CD:DA=1:1.15:2.9:3.0, Fig.14 As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Fig.15 As shown, the height of the foldable wheelchair 10 in the folded state is 304 mm, and the length of the foldable wheelchair 10 is 701 mm.

[0025] (3) When AB:BC:CD:DA=1:1.2:3.8:3.9, Fig.16 As shown, the height of the foldable wheelchair 10 in the unfolded state is 930 mm, and the length of the foldable wheelchair 10 is 780 mm; Fig.17 As shown, the height of the foldable wheelchair 10 in the folded state is 301 mm, and the length of the foldable wheelchair 10 is 701 mm.

[0026] Among them, in the above embodiments, no matter the folding wheelchair 10 is set according to the parameters in the embodiment of the present application or according to the parameters in the prior art, the diameter of the front wheel 101 of the folding wheelchair 10 is 186 mm, and the diameter of the rear wheel 301 of the folding wheelchair 10 is 254 mm.

[0027] It can be seen from the above content that when the length and height of the folding wheelchair 10 are the same in the unfolded state, when the positional relationship between the hinge points in the first four-link assembly of the folding wheelchair 10, and the length ratio relationship of the straight line formed by the hinge points are the same as those in the embodiment of the present application, the length and height of the folding wheelchair 10 are shorter after folding, and the length can be shortened by about 1 / 10 compared with the prior art, and the wheelchair has a more compact structure after folding; when the width after folding is the same, if the length and height of the wheelchair are shorter, the occupied area and volume are also smaller, which is conducive to storing the folding wheelchair 10 in a small space, thereby improving the user experience.

[0028] Furthermore, in the embodiment of the present application, in the second four-link assembly, hinge point G and hinge point F are located on the center plane of the seat cushion 600, and hinge point E and hinge point A are located below the center plane of the seat cushion 600; the positional relationship between hinge point E, hinge point F, hinge point G and hinge point A satisfies EF:FG:GA:AE=(2.59~16.3):(4.86~20.4):1:(3.02~5.19); wherein EF is the straight line formed by hinge point E and hinge point F, FG is the straight line formed by hinge point F and hinge point G, GA is the straight line formed by hinge point G and hinge point A, and AE is the straight line formed by hinge point A and hinge point E; the above positional relationship represents the length relationship between the straight lines.

[0029] Figure 6 and Figure 7 The positional relationship between the hinge points in the second four-link assembly satisfies EF:FG:GA:AE=2.59:4.86:1:3.02; Figure 8 and Fig. 9 The positional relationship between the hinge points in the second four-link assembly satisfies EF:FG:GA:AE=4.37:7.44:1:3.86; Fig.10 and Fig.11 The positional relationship between the hinge points in the second four-bar linkage assembly satisfies EF:FG:GA:AE=16.3:20.4:1:5.19. It can be seen that when the positional relationship between the hinge points in the second four-bar linkage assembly of the folding wheelchair 10 and the length ratio relationship of the straight line formed by the hinge points are the same as those in the embodiment of the present application, the backrest assembly 200 of the folding wheelchair 10 is basically parallel to the placement surface for placing the wheelchair after folding, which makes the center of gravity of the wheelchair stable after folding and not easy to tip over.

[0030] Furthermore, a soft cushion is usually installed on the backrest assembly 200, and a soft cushion is installed on the seat cushion 600, so that the user can have a better experience when sitting in the wheelchair. In the prior art, some wheelchairs need to first remove the cushion from the backrest assembly 200 and the cushion from the seat cushion 600, and then fold the wheelchair after the disassembly is completed. This folding method is cumbersome and brings a poor user experience. In the embodiment of the present application, the wheelchair can be folded without removing the cushion from the backrest assembly 200 and the cushion from the seat cushion 600. The folding method is simple and brings a good user experience.

[0031] In addition, in the embodiment of the present application, the wheelchair can be folded in one step by pushing the backrest assembly 200. Compared with the prior art that requires multiple steps to fold the wheelchair, the folding method of the present application is simple and highly intelligent. At the same time, in the present application, the wheelchair can be unfolded in one step by pulling the backrest assembly 200, and the unfolding method is simple.

[0032] In a possible implementation, in the first four-bar linkage assembly, the positional relationship between the hinge points satisfies AB:BC:CD:DA=1:1.03:5.02:4.8; and / or the length of AB is 40 mm to 60 mm.

[0033] In a possible implementation, in the second four-bar linkage assembly, the positional relationship between the hinge points satisfies EF:FG:GA:AE=3.1:7.4:1:4.89; and / or, the length of GA is 16.9 mm to 42.2 mm.

[0034] In a possible implementation, Figure 3 As shown, the first reference plane is perpendicular to the placement plane for placing the wheelchair, and in the unfolded state, the inclination angle of the backrest assembly 200 relative to the first reference plane N1 is 10-15°. Exemplarily, the inclination angle of the backrest assembly 200 relative to the first reference plane N1 can be 14°. The above inclination angle is the angle at which the backrest assembly 200 is inclined away from the front support 100.

[0035] In the above embodiment, by setting the inclination angle of the backrest assembly 200 , the user can lean on the backrest assembly 200 in a more comfortable posture.

[0036] In a possible implementation, Figure 3As shown, the second reference plane N2 is parallel to the placement surface for placing the wheelchair, and in the unfolded state, the inclination angle of the seat cushion 600 relative to the second reference plane N2 is 2-5°. For example, the inclination angle of the seat cushion 600 relative to the second reference plane can be 3°. The above inclination angle is the angle at which the seat cushion 600 is inclined away from the placement surface.

[0037] In the above embodiment, the inclination angle of the seat cushion 600 is set so that the user can sit on the seat cushion 600 in a more comfortable posture.

[0038] Based on the above embodiments, Fig.18 As shown, the backrest assembly 200 includes a backrest component 201 and a fixing component 202, and the backrest component 201 can rotate relative to the fixing component 202; when the wheelchair is in the unfolded state, the user sits on the folding wheelchair 10, and his back will lean on the cushion provided on the backrest component 201, and the backrest component 201 is at an initial angle; wherein, this initial angle is the angle of the backrest component 201 relative to the first reference plane N1, and the angle can be 10-15°; the user can rotate the backrest component 201 to a certain angle according to his own needs, and then lean on the backrest component 201 in a more comfortable posture. Specifically, a locking component 203 is provided at the end of the backrest component 201, and the fixing component 202 is located on one side of the locking component 203; a plurality of first matching components P are distributed in a circular array on the locking component 203, and a plurality of second matching components H corresponding to the plurality of first matching components P are distributed in a circular array on the fixing component 202; the misalignment angle between any first matching component P and the corresponding second matching component H is the rotatable angle of the backrest component 201.

[0039] During an operation, when the backrest component 201 is adjusted from the initial angle to Figure 1 When rotating in the counterclockwise direction K1, if the rotation angle is equal to the misalignment angle of a first matching member and a second matching member, the first matching member and the second matching member cooperate to fix the backrest so that the backrest component 201 can be kept at the rotation angle. In this way, the rotation angle of the backrest component 201 can be adjusted.

[0040] Wherein, when the backrest component 201 is in accordance with Figure 1 When rotating in the counterclockwise direction K1, starting from a first matching member and a second matching member, the misalignment angle between each first matching member and the corresponding second matching member in the counterclockwise direction K gradually decreases. In this way, when the backrest component 201 rotates to a certain angle, there will be a first matching member and a second matching member cooperating to fix the backrest component 201, so that the backrest component 201 remains at the current rotation angle. For example, Fig.19 , Fig.21 and Fig. 22As shown, the locking component 203 is provided with four first matching pieces, namely P1, P2, P3 and P4. Fig.18 When observed in the direction of the middle arrow, P1, P2, P3 and P4 are distributed on the locking component 203 in a circular array in the counterclockwise direction K1; Fig. 20 , Fig.21 and Fig. 22 As shown, the fixing member 202 is provided with four second matching members, namely H1, H2, H3 and H4. Fig.18 When viewed from the direction of the middle arrow, H1, H2, H3 and H4 are distributed on the fixing member 202 in a circular array in the counterclockwise direction K1. Fig.18 When observing in the direction of the middle arrow, with the first matching piece P1 and the second matching piece H1 as the starting point, in the counterclockwise direction K1, the misalignment angle between P1 and H1 is 15°, the misalignment angle between P2 and H2 is 10°, the misalignment angle between P3 and H3 is 5°, and the misalignment angle between P4 and H4 is 0°. Fig.21 As shown, when the backrest component 201 is at the initial angle, P4 and H4 cooperate to fix the backrest component 201 so that the backrest component 201 remains at the initial angle; Fig. 22 As shown, when the backrest component 201 rotates 5° from the initial angle, P3 and H3 cooperate to fix the backrest component 201 so that the backrest component 201 remains at the current rotation angle; when the backrest component 201 rotates 10° from the initial angle, P2 and H2 cooperate to fix the backrest component 201 so that the backrest component 201 remains at the current rotation angle; when the backrest component 201 rotates 15° from the initial angle, P1 and H1 cooperate to fix the backrest component 201 so that the backrest component 201 remains at the current rotation angle.

[0041] Of course, it is understandable that, in practice, the number of the first matching member and the second matching member can be set according to actual needs, such as 4, 8, 12, 20, etc. At the same time, the angle difference between the first matching member and the second matching member can be any value such as 1°, 2°, 3°, 5°, 7°, 10°, etc., and this embodiment does not limit this.

[0042] In the prior art, when adjusting the rotation angle of the backrest component 201, fine adjustment cannot be achieved, that is, the difference between the adjustable angles of the backrest component 201 is large. However, in the present application, when adjusting the rotation angle of the backrest component 201 by forming a misalignment angle between the first matching member and the second matching member, the rotation angle of the backrest component 201 can be finely adjusted by setting the above-mentioned misalignment angle more finely, thereby improving the user experience when riding a wheelchair. For example, the misalignment angle between P1 and H1 can be set to 6°, the misalignment angle between P2 and H2 can be set to 4°, the misalignment angle between P3 and H3 can be set to 2°, and the misalignment angle between P4 and H4 can be set to 0°, so that the rotation angle of the backrest component 201 can be finely adjusted.

[0043] Based on the above embodiments, Fig.19 As shown, the first matching member is a cylindrical pin provided on the locking member 203, such as Fig. 20 As shown, the second matching piece is a mounting hole provided on the fixing member 202. Alternatively, the first matching piece is a mounting hole provided on the locking member 203, and the second matching piece is a cylindrical pin provided on the fixing member 202.

[0044] In an operation, when adjusting the rotation angle of the backrest component 201, the user can move the locking component 203 away from the fixing component 202. When the locking component 203 moves to the first position, the first matching member that was previously in a matching state is unmatched from the corresponding second matching member, and the backrest component 201 is in an unlocked state in which the angle can be adjusted. After the backrest component 201 is in the unlocked state, the user can move the backrest component 201 to Figure 1 The locking component 203 rotates synchronously in the counterclockwise direction K1 as shown, and when the backrest component 201 rotates, the first matching component and the second matching component whose offset angle is the target angle are aligned; the user can move the locking component 203 toward the direction close to the fixing component 202, and when the locking component 203 moves to the second position, the first matching component and the second matching component whose offset angle is the target angle cooperate, and the backrest component 201 is fixed at the current angle and switched to a locked state where the angle cannot be adjusted.

[0045] In the above embodiment, the rotation angle of the backrest component 201 is adjusted by forming a misalignment angle between the locking pin and the mounting hole. The adjustment method is simple and easy to implement.

[0046] Based on the above embodiments, Fig.18As shown, a first elastic element 204 is provided between the end of the backrest component 201 and the locking component 203, and the first elastic element 204 is used to provide a force for the locking component 203 to move toward the fixed component 202. Specifically, when the user moves the locking component 203 to the first position in the direction away from the fixed component 202, the first elastic element 204 undergoes elastic deformation. When the backrest component 201 rotates to the above target angle, the user can release the locking component 203. After the locking component 203 is released, the first elastic element 204 recovers the elastic deformation and generates an elastic force. The locking component 203 moves toward the fixed component 202 under the action of the elastic force of the first elastic element 204. In this way, the locking component 203 can automatically move toward the fixed component 202 without the user having to act on the locking component 203, thereby reducing the control burden of the user and improving the intelligence of the folding wheelchair 10.

[0047] Based on the above embodiments, Fig.18 As shown, a second elastic element 205 is provided between the end of the backrest component 201 and the fixing component 202, and the second elastic element 205 is used to provide a restoring force to the backrest component 201 to restore the backrest component 201 to the initial angle. Figure 1 When the counterclockwise direction K1 shown is rotated from the initial angle to the target angle, the second elastic element 205 undergoes elastic deformation; when the user wants to rotate the backrest component 201 from the target angle to the initial angle, the user can move the locking component 203 to the first position in the direction away from the fixed component 202 to switch the backrest component 201 to an unlocked state capable of angle adjustment, and then the user releases the backrest component 201, and the backrest component 201 can be restored to the initial angle under the elastic action of the second elastic element 205; then the user can move the locking component 203 to the second position in the direction close to the fixed component 202 to maintain the backrest component 201 at the initial angle. Exemplarily, the second elastic element 205 can be a torsion spring.

[0048] Based on the above embodiments, Fig.23 As shown, the end of the backrest component 201 may be provided with an open mounting groove 2012, the end of the fixing component 202 is located in the mounting groove 2012, and the groove wall of the mounting groove 2012 is provided with a first limiting surface 20121 and a second limiting surface 20122 located below the first limiting surface 20121; Fig.24 As shown, the end of the fixing member 202 is provided with a third limiting surface 2021 opposite to the first limiting surface 20121 and a fourth limiting surface 2022 opposite to the second limiting surface 20122. When the backrest member 201 is at the initial angle, the first limiting surface 20121 abuts against the third limiting surface 2021; the backrest member 201 is arranged according to Figure 1 When the backrest component 201 rotates counterclockwise in the direction K1 to the maximum adjustment angle, the second limit surface 20122 abuts against the fourth limit surface 2022. The maximum adjustment angle is the angle at which the backrest component 201 rotates counterclockwise in the direction K1 to the maximum adjustment angle. Figure 1 The angle between the backrest component 201 and the first reference plane N1 after the backrest component 201 rotates to the maximum angle in the counterclockwise direction K1 (away from the seat) as shown. For example, assuming that the initial angle of the backrest component 201 is 15°; when the backrest component 201 rotates to the maximum angle in the counterclockwise direction K1 (away from the seat), the backrest component 201 rotates to the maximum angle in the counterclockwise direction K1 (away from the seat) as shown. Figure 1 As shown, after rotating 50° in the counterclockwise direction K1 , the backrest component 201 cannot rotate further, and the angle between the backrest component 201 and the first reference plane N1 is 65°. At this time, the maximum rotation angle of the backrest component 201 is 65°.

[0049] Based on the above embodiments, Fig.18 As shown, the end of the backrest component 201 is provided with a first protrusion 2011 and a second protrusion 2013 at intervals, and an open installation groove 2012 is formed between the first protrusion 2011 and the second protrusion 2013. The opening of the installation groove 2012 faces the fixed component 202, and the end of the fixed component 202 is located in the installation groove 2012, and a plurality of second matching parts are distributed in a circumferential array at the end of the fixed component 202. The rotation axis 208 of the backrest component 201 is fixedly arranged in the first protrusion 2011, the end of the fixed component 202 and the second protrusion 2013 along the axial direction; wherein the second matching part can be arranged around the rotation axis 208 of the backrest component 201. The end of the fixed component 202 away from the installation groove 2012 is hinged to the front support 100, the rear support 300 and the seat cushion 600.

[0050] like Fig.18 and Fig.19 As shown, the locking component 203 is provided with a first end face 2031 and a second end face 2032 along the axial direction, and the first protrusion 2011 is provided with a third end face 20112 and a fourth end face 20113 along the axial direction; the first protrusion 2011 is provided with a receiving groove 20111, and the locking component 203 is located in the receiving groove 20111, and the first end face 2031 of the locking component 203 is arranged opposite to the third end face 20112 of the first protrusion 2011, and the second end face 2032 of the locking component 203 is arranged opposite to the fourth end face 20113 of the first protrusion 2011. The end of the fixing component 202 is provided with a fifth end face 2024 opposite to the fourth end face 20113.

[0051] like Fig.18 and Fig.19As shown, a connecting shaft 2033 is provided on the first end surface 2031 of the locking component 203, and one end of the connecting shaft 2033 away from the locking component 203 passes through the third end surface 20112 of the first protrusion 2011 and is connected to the handle 206 disposed outside the folding wheelchair 10. The first elastic element 204 is located in the receiving groove 20111, sleeved on the connecting shaft 2033, one end of which abuts against the locking component 203, and the other end of which abuts against the third end surface 20112 of the first protrusion 2011.

[0052] The locking component 203 is provided with a circular array of first through holes, the same number as the first matching pieces, and an elastic element is fixed in each first through hole; wherein each elastic element can be fixed in the corresponding first through hole by a set screw. One end of each first matching piece extends into the corresponding first through hole and is connected to the elastic element arranged in the first through hole, and the other end of each first matching piece extends out through the second surface of the locking component 203; a plurality of accommodating through holes (not shown in the figure) are distributed in a circular array on the fourth surface of the first protrusion 2011, and the plurality of accommodating through holes are aligned one by one with the plurality of first matching pieces, and the other end of each first matching piece passes out through the corresponding accommodating through hole. wherein the first through holes, accommodating through holes, and first matching pieces can all be arranged around the rotation axis 208 of the backrest component 201.

[0053] For example, Fig.25 For example, the locking member 203 is provided with first through holes R1, R2, R3 and R4; and according to Fig.18 When viewed in the direction of the middle arrow, the first through holes R1, R2, R3 and R4 are arranged in Figure 1 The counterclockwise direction K1 circular array is distributed on the locking component 203; at this time, one end of the first matching component P1 extends into the first through hole R1 and is connected to the elastic element provided in the first through hole R1, and the other end of the first matching component P1 passes through the second surface of the locking component 203 and the corresponding accommodating through hole; one end of the second matching component P2 extends into the first through hole R2 and is connected to the elastic element provided in the first through hole R2, and the other end of the first matching component P2 passes through the second surface of the locking component 203 and the corresponding accommodating through hole; one end of the second matching component P3 extends into the first through hole R3 and is connected to the elastic element provided in the first through hole R3, and the other end of the first matching component P3 passes through the second surface of the locking component 203 and the corresponding accommodating through hole; one end of the second matching component P4 extends into the first through hole R4 and is connected to the elastic element provided in the first through hole R4, and the other end of the first matching component P4 passes through the second surface of the locking component 203 and the corresponding accommodating through hole.

[0054] like Fig.23 and Fig.24As shown, the second elastic element 205 is sleeved on the rotating shaft 208 of the backrest part 201, and the end of the fixed part 202 is provided with a receiving groove 2023 connected to the installation groove 2012. The second elastic element 205 is located in the above-mentioned receiving groove 2023, and one end is connected to the groove wall of the installation groove 2012, and the other end is connected to the groove wall of the receiving groove 2023.

[0055] like Fig.23 and Fig.24 As shown, the first limiting surface 20121 and the second limiting surface 20122 can be disposed around the rotation axis 208 of the backrest component 201 , and the third limiting surface 2021 and the fourth limiting surface 2022 can be disposed around the rotation axis 208 of the backrest component 201 .

[0056] like Fig.23 and Fig.25 As shown, a first clamping plane 20114 is provided on the side wall of the receiving groove 20111, and a second clamping plane 2034 is provided on the side wall of the locking component 203 to contact the first clamping plane 20114. When the first clamping plane 20114 and the second clamping plane 2034 are in the above-mentioned contact relationship, the locking component 203 is driven to rotate synchronously when the backrest component 201 rotates.

[0057] The locking member 203 is provided with first matching parts P1, P2, P3 and P4 (see Fig.21 and Fig. 22 ), the fixing member 202 is provided with second matching parts H1, H2, H3 and H4 (see Fig.21 and Fig. 22 ), taking the first matching member P1 and the second matching member H1 as the starting point, in the counterclockwise direction K1, the misalignment angle between P1 and H1 is 30°, the misalignment angle between P2 and H2 is 20°, the misalignment angle between P3 and H3 is 10°, and the misalignment angle between P4 and H4 is 0° as an example, the angle adjustment principle of the backrest component 201 in this embodiment is explained: When the user sits on the wheelchair, his back leans against the backrest component 201, and the first matching component P4 and the second matching component H4 cooperate to fix the backrest component 201. The backrest component 201 is at an initial angle, and the first limiting surface 20121 on the wall of the installation groove 2012 and the third limiting surface 2021 at the end of the fixing component 202 are in contact. When the user wants to adjust the angle of the backrest component 201, the user holds the handle 206 so that the handle 206 drives the locking component 203 to move away from the fixing component 202. During the movement of the locking component 203, the first elastic element 204 is compressed. When the locking component 203 moves to the first position, the first matching component P4 and the second matching component H4 are released, and the backrest component 201 switches to an unlocked state in which the angle can be adjusted. At this time, the user presses the button 206 to adjust the angle of the backrest component 201. Figure 1The backrest component 201 is leaned against in the counterclockwise direction K1, so that the backrest component 201 rotates in the counterclockwise direction K1. During the rotation of the backrest component 201, the locking component 203 is driven to rotate synchronously, and the second elastic element 205 is elastically deformed; Fig.26 As shown, when the rotation angle of the backrest component 201 is 10°, the first matching component P3 and the second matching component H3 are aligned, the user releases the handle 206, and the locking component 203 moves toward the direction close to the fixed component 202 under the elastic action of the first elastic element 204. When moving to the second position, the first matching component P3 and the second matching component H3 cooperate to lock the backrest component 201, and the first matching components P1, P2 and P4 abut against the fifth end surface 2024 of the fixed component 202, and the backrest component 201 switches to a locked state in which the angle cannot be adjusted.

[0058] like Fig. 27 As shown, when the rotation angle of the backrest component 201 is 20°, the first matching component P2 and the second matching component H2 are aligned, the user releases the handle 206, and the locking component 203 moves toward the direction close to the fixed component 202 under the elastic action of the first elastic element 204. When moving to the second position, the first matching component P2 and the second matching component H2 cooperate to lock the backrest component 201, and the first matching components P1, P3 and P4 abut against the fifth end surface 2024 of the fixed component 202, and the backrest component 201 switches to a locked state in which the angle cannot be adjusted.

[0059] like Fig.28 As shown, when the rotation angle of the backrest component 201 is 30°, the first matching piece P1 and the second matching piece H1 are aligned, the user releases the handle 206, and the locking component 203 moves toward the direction close to the fixed component 202 under the elastic action of the first elastic element 204. When it moves to the second position, the first matching piece P1 and the second matching piece H1 cooperate to lock the backrest component 201, and the first matching pieces P2, P3 and P4 abut against the fifth end face 2024 of the fixed component 202, and the backrest component 201 switches to a locked state where the angle cannot be adjusted. At the same time, at this time, the second limiting surface 20122 on the groove wall of the installation groove 2012 abuts against the fourth limiting surface 2022 located at the end of the fixed component 202.

[0060] When the user wants to adjust the backrest component 201 from the rotated angle to the initial angle after the backrest component 201 rotates, the user can first hold the handle 206 to make the handle 206 drive the locking component 203 to move away from the fixing component 202. During the movement of the locking component 203, the first elastic element 204 is compressed. When the locking component 203 moves to the first position, the previously matched first matching member and the second matching member are released, and the backrest component 201 is switched to an unlocked state in which the angle can be adjusted. At this time, the user stops leaning on the backrest and moves his body toward the backrest. Figure 1 The backrest component 201 is tilted forward in a clockwise direction opposite to the direction of K1, and under the elastic action of the second elastic element 205, the backrest component 201 returns to the initial angle, and the first matching piece P4 and the second matching piece H4 are aligned. The user releases the handle 206, and the locking component 203 moves toward the direction close to the fixed component 202 under the elastic action of the first elastic element 204. When it moves to the second position, the first matching piece P4 and the second matching piece H4 cooperate to lock the backrest component 201, and the first matching pieces P1, P2 and P3 abut against the fifth end face 2024 of the fixed component 202, and the backrest component 201 is successfully switched to the initial angle.

[0061] In the prior art, it is usually necessary to set the element for adjusting the angle of the backrest component 201 outside the folding wheelchair 10. This method cannot be perfectly combined with the folding wheelchair 10 and has poor structural integration. In the above embodiment of the present application, the element for adjusting the angle of the backrest component 201 is integrated inside the folding wheelchair 10 product, thereby improving the structural integration of the folding wheelchair 10.

[0062] Based on the above embodiments, Figure 29-Figure 32 As shown, the folding wheelchair 10 further includes a headrest assembly, which includes a rod 702 and a headrest 701 connected to one end of the rod 702, the other end of the rod 702 extends into the backrest component 201, and the rod 702 is provided with a plurality of adjustment holes 7021 arranged along the height direction of the folding wheelchair 10. In order to accommodate users of different heights, the height of the headrest 701 can be adjusted in the height direction of the folding wheelchair 10; wherein, the headrest assembly further includes an adjustment component, and the user can adjust the height of the headrest 701 through the adjustment component. Specifically, the adjusting component is located on one side of the rod 702, and the adjusting component includes an adjusting component 801, an adjusting pin 802 and a third elastic element 803; the adjusting component 801 is partially exposed; the adjusting pin 802 is arranged in the backrest component 201, located below the adjusting component 801 and one end is inserted into any adjusting hole 7021, and the adjusting pin 802 is provided with a slope 80211; the third elastic element 803 is located in the backrest component 201, and the other end of the adjusting pin 802 abuts against the third elastic element 803.

[0063] When adjusting the height of the headrest 701, the user can press down the adjusting member 801 to make the adjusting member 801 move downward; when the adjusting member 801 moves downward, the end of the adjusting member 801 slides on the inclined surface 80211, pushing the adjusting pin 802 to move away from the rod 702; when the adjusting pin 802 moves to the specified position, it disengages from the adjusting hole 7021 and causes the third elastic element 803 to undergo elastic deformation. At this time, the user can move the headrest assembly in the height direction, and when it moves to a suitable height, the user lifts up the adjusting member 801 to make the adjusting member 801 move upward; when the adjusting member 801 moves upward, the end of the adjusting member 801 disengages from the inclined surface 80211, and the adjusting pin 802 moves toward the rod 702 under the elastic action of the third elastic element 803; when the adjusting pin 802 moves to the specified position, it extends into the adjusting hole 7021 to lock the headrest assembly so that the headrest assembly remains at the current height.

[0064] Based on the above embodiments, Figure 29-Figure 32 As shown, the adjustment component also includes a fourth elastic element 804 disposed in the backrest component 201, and the fourth elastic element 804 is used to provide an upward movement force to the adjustment component 801. Specifically, in this embodiment, when adjusting the height of the headrest 701, the user presses the adjustment component 801 downward, and the adjustment component 801 causes the fourth elastic element 804 to undergo elastic deformation, and the adjustment pin 802 escapes from the adjustment hole 7021; then the user adjusts the height of the headrest 701, and after the adjustment is completed, the user releases the adjustment component 801, and the adjustment component 801 moves upward under the elastic action of the fourth elastic element 804, and the adjustment pin 802 extends into the adjustment hole 7021 to lock the headrest assembly.

[0065] Based on the above embodiments, Fig.31 As shown, a slideway 207 extending in the height direction of the folding wheelchair 10 may be provided in the backrest component 201, and the rod 702 is located in the slideway 207. When the height of the headrest assembly is adjusted, the rod 702 slides in the slideway 207 along the height direction.

[0066] Based on the above embodiments, Figure 29-Figure 32As shown, two rods 702 are symmetrically provided, one end of each rod 702 is connected to the headrest 701, two slideways 207 are symmetrically provided in the backrest component 201, and the other end of each rod 702 extends into the corresponding slideway 207; the adjustment member 801 is located between the two rods 702, and the adjustment member 801 includes a body 8011 that is partially exposed, two adjustment rods 8012 that are symmetrically provided on the body 8011 and located in the backrest component 201, a fixing rod 8013 is provided between the two adjustment rods 8012, and a fourth elastic element 804 is located in the backrest component 201. and connected to the fixing rod 8013; there are two adjusting pins 802, each of which is provided with an inclined hole 8021, the top of each inclined hole 8021 is connected to the end of an adjusting rod 8012, the bottom of each inclined hole 8021 is sealed, and the adjusting rod 8012 is limited, and the side wall of each inclined hole 8021 forms a slope 80211; one end of each adjusting pin 802 can extend into the adjusting hole 7021 of the corresponding rod 702; the third elastic element 803 is located between the two adjusting pins 802 and is connected to the other end of each adjusting pin 802.

[0067] When the user adjusts the height of the headrest 701, the user can press the main body 8011 downward to make the main body 8011 move downward; when the main body 8011 moves downward, it drives the two adjustment rods 8012 to move downward and the fourth elastic element 804 is compressed. During the downward movement of the adjustment rod 8012, it slides on the inclined surface 80211 of the corresponding inclined hole 8021, pushing the adjustment pin 802 to move away from the corresponding rod 702. During the movement of the adjustment pin 802, the third elastic element 803 is compressed. When the adjustment rod 8012 slides to the bottom end of the adjustment hole 7021, it stops sliding, and the adjustment pin 802 completely disengages from the corresponding adjustment hole 7021. At this time, the user can move the headrest assembly in the height direction, and during the movement, the rod 702 slides in the corresponding slide 207; when it moves to the appropriate height, the user stops pressing the main body 8011, and the main body 8011 and the adjustment rod 8012 move upward under the elastic action of the fourth elastic element 804, and the adjustment rod 8012 disengages from the inclined surface 80211 when moving upward, and the two adjustment pins 802 move toward the direction close to the rod 702 under the elastic action of the third elastic element 803; when the adjustment pin 802 moves to the specified position, it extends into the adjustment hole 7021 to lock the headrest assembly so that the headrest assembly remains at the current height.

[0068] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A folding wheelchair, characterized in that: The folding wheelchair comprises: The first four-link assembly comprises a front support, a backrest assembly, a rear support and front and rear pull rods which are hinged in sequence, wherein the front support, the backrest assembly, the rear support and the front and rear pull rods are hinged to form a hinge point A, a hinge point B, a hinge point C and a hinge point D, and the positional relationship between the hinge points satisfies AB:BC:CD:DA=1:(0.8~1.05):(2.08~8.48):(1.76~8.39); The second four-link assembly comprises a front support, a seat cushion support rod, a seat cushion, and a backrest assembly which are hinged in sequence, wherein the front support, the seat cushion support rod, the seat cushion, and the backrest assembly are hinged to form a hinge point E, a hinge point F, a hinge point G, and a hinge point A, and the positional relationship between the hinge points satisfies EF:FG:GA:AE=(2.59~16.3):(4.86~20.4):1:(3.02~5.19); The hinge point G and the hinge point F are located on the center plane of the seat cushion, and the hinge point A, the hinge point B, the hinge point C, the hinge point D and the hinge point E are located below the center plane of the seat cushion.

2. The folding wheelchair according to claim 1, characterized in that: In the first four-link assembly, the positional relationship between the hinge points satisfies AB:BC:CD:DA=1:1.03:5.02:4.

8.

3. The folding wheelchair according to claim 1 or 2, characterized in that: In the second four-bar linkage assembly, the positional relationship between the hinge points satisfies EF:FG:GA:AE=3.1:7.4:1:4.

89.

4. The folding wheelchair according to claim 1, characterized in that: The foldable wheelchair is placed on a placement surface, a first reference surface is perpendicular to the placement surface, and an inclination angle of the backrest assembly relative to the first reference surface is 10-15°.

5. The folding wheelchair according to claim 4, characterized in that: The second reference surface is parallel to the placement surface, and the seat cushion has an inclination angle of 2-5° relative to the second reference surface.

6. The folding wheelchair according to claim 1, characterized in that: The length of AB is 40 mm to 60 mm.

7. The folding wheelchair according to claim 1, characterized in that: The length of the GA is 16.9 mm to 42.2 mm.

8. The folding wheelchair according to claim 1, characterized in that: The backrest assembly comprises a backrest component and a fixing component connected to each other, a locking component is provided at an end of the backrest component, and the fixing component is located on one side of the locking component; A plurality of first matching pieces are distributed in a circumferential array on the locking component, and a plurality of second matching pieces are distributed in a circumferential array on the fixing component corresponding to the plurality of first matching pieces one by one; The misalignment angle between any one of the first matching parts and the corresponding second matching part is the rotatable angle of the backrest component.

9. The folding wheelchair according to claim 8, characterized in that: The first matching member is a cylindrical pin provided on the locking member, and the second matching member is a mounting hole provided on the fixing member; Alternatively, the first matching member is a mounting hole provided on the locking member, and the second matching member is a cylindrical pin provided on the fixing member; Among them, when the locking component moves to the first position in the direction away from the fixing component, the first matching component and the corresponding second matching component are released from cooperation, and the backrest component is in an unlocked state capable of adjusting the angle; after the backrest component is rotated to a target angle, when the locking component moves to the second position in the direction close to the fixing component, the first matching component and the second matching component with the misalignment angle of the target angle cooperate, and the backrest component is switched to a locked state where the angle cannot be adjusted.

10. The folding wheelchair according to claim 1, characterized in that: The folding wheelchair further comprises a headrest assembly, comprising a rod and a headrest connected to one end of the rod, the other end of the rod extends into the backrest assembly, and the rod is provided with a plurality of adjustment holes arranged along the height direction of the folding wheelchair; The adjusting component comprises a partially exposed adjusting member, an adjusting pin arranged in the backrest assembly, located below the adjusting member and having one end inserted into the adjusting hole, and a third elastic element arranged in the backrest assembly; the other end of the adjusting pin abuts against the third elastic element; Wherein, the adjusting pin is provided with an inclined surface, and when the adjusting member moves downward, the end of the adjusting member slides on the inclined surface, pushing the adjusting pin out of the adjusting hole to cause the third elastic element to undergo elastic deformation; When the adjusting member moves upward, the end of the adjusting member is separated from the inclined surface, and the adjusting pin extends into the adjusting hole under the elastic action of the third elastic element.

Images