Automatic tightener and antiskid chain assembly

Abstract

The invention provides an automatic tightener and an antiskid chain assembly. The automatic tightener comprises a shell, a ratchet wheel, a wrench, a first non-return assembly and a second non-return assembly. The ratchet wheel is arranged in the shell and is rotationally connected with the shell; a first ratchet part and a second ratchet part are respectively arranged on the circumferential wall of the ratchet wheel, and the first ratchet part and the second ratchet part are arranged in parallel in the axial direction of the ratchet wheel; the wrench comprises a first end arranged outside the shell and a second end arranged in the shell; the wrench rotates relative to the shell, so that the first end is far away from the shell, the second end drives the first non-return assembly and the second non-return assembly, the second non-return assembly and the second ratchet part are clamped, and the ratchet wheel can rotate in the first direction; the wrench rotates relative to the shell so that the first end can be attached to the shell, the first non-return assembly is clamped with the first ratchet part so that the ratchet wheel can rotate in the second direction, and the first direction is opposite to the second direction. The automatic tightener and the antiskid chain assembly have the advantages of being simple in structure, convenient to use, safe and reliable.

Description

Technical Field

[0001] This application relates to the field of mechanical tightening devices, and in particular to an automatic tightener and anti-skid chain assembly. Background Technology

[0002] In winter or in severe weather conditions, roads are prone to icy or snowy conditions. To ensure driving safety, many car owners install snow chain kits to increase the friction between the tires and the ground, reducing the accident rate. When installing snow chain kits on tires, the chain body is usually first slipped onto the tire, and then a tensioner is used to tighten the chain body, thereby locking the chain body onto the tire and preventing it from falling off.

[0003] In the process of developing this application, the inventors discovered that the prior art has at least the following problems: most existing tensioners cannot achieve automatic tensioning and require manual operation, which is very inconvenient to use. Moreover, after the tensioners in the prior art achieve the locking function, their reliability is poor, and there is a risk that the chain body may fall off, such as the locking device being accidentally activated, causing the locking function to fail. Summary of the Invention

[0004] Based on this, this application provides an automatic tensioner and anti-slip chain assembly to improve the problems of inconvenience in use and poor reliability in the prior art.

[0005] To achieve the above objectives, the technical solution of this application embodiment is implemented as follows: On one hand, this application provides an automatic tightening device, including a housing, a ratchet, a wrench, a first check valve assembly, and a second check valve assembly. The ratchet is disposed inside the housing and rotatably connected to the housing. A first ratchet portion and a second ratchet portion are respectively provided on the circumferential wall of the ratchet, and the first ratchet portion and the second ratchet portion are arranged side by side along the axial direction of the ratchet. The wrench includes a first end disposed outside the housing and a second end disposed inside the housing. The wrench rotates relative to the housing to move the first end away from the housing, so that the second end drives the first check valve assembly and the second check valve assembly, causing the first check valve assembly to separate from the first ratchet portion, and causing the second check valve assembly to engage with the second ratchet portion, thereby enabling the ratchet to rotate in a first direction. The wrench rotates relative to the housing to make the first end fit against the housing, the first check valve assembly engages with the first ratchet portion, and the second check valve assembly separates from the second ratchet portion, so that the ratchet can rotate in a second direction, the first direction and the second direction being opposite.

[0006] In one embodiment, the wrench includes a connecting portion and a force-applying portion and a cam portion respectively disposed at both ends of the connecting portion, the force-applying portion being disposed at a first end of the wrench and the cam portion being disposed at a second end of the wrench.

[0007] In one embodiment, the wrench is provided with a hook, and the outer wall of the housing is provided with a snap-fit ​​part that cooperates with the hook.

[0008] In one embodiment, the second end of the wrench is provided with a protruding first stop, and the inner wall of the housing is provided with a corresponding protruding second stop. The first stop and the second stop cooperate to keep the first end of the wrench away from the housing.

[0009] In one embodiment, the first check valve assembly includes a connecting rod and a first reset device. The middle part of the connecting rod is rotatably connected to the housing. The cam portion is used to drive one end of the connecting rod to separate the first pawl and the first ratchet. The other end of the connecting rod is provided with the first reset device and the first pawl on both sides respectively. The first reset device is used to drive the other end of the connecting rod to engage the first pawl and the first ratchet.

[0010] In one embodiment, the second check valve assembly includes a slider and a second reset device. The slider has a second pawl at one end away from the cam portion. The inner wall of the housing has a receiving cavity with a guide groove. The cam portion drives the slider to move towards the ratchet, so that the second pawl extends out of the receiving cavity along the guide groove and engages with the second ratchet tooth. The second reset device drives the slider to move away from the ratchet, so that the second pawl enters the receiving cavity along the guide groove and disengages from the second ratchet tooth.

[0011] In one embodiment, the automatic tightener further includes a steel cable, one end of which is fixed to the ratchet, and the other end of which is connected to a handle located outside the housing. The steel cable is used to wind around the ratchet between the first ratchet tooth and the second ratchet tooth, and pulling the handle outwards drives the ratchet to rotate in the first direction.

[0012] In one embodiment, the automatic tightener further includes an energy-storing coil spring. The ratchet has a mounting cavity, and the energy-storing coil spring is installed in the mounting cavity. One end of the energy-storing coil spring is fixedly connected to the ratchet, and the other end is fixedly connected to the housing. The energy-storing coil spring is used to drive the ratchet to rotate in the second direction.

[0013] On the other hand, embodiments of this application provide an anti-skid chain assembly, including a chain body and an automatic tensioner as described above, wherein the automatic tensioner is connected to the chain body.

[0014] In one embodiment, the housing has at least one connection hole, the ratchet has a handle, the handle has a connecting part, and the connection hole and the connecting part are respectively used to connect to the chain body.

[0015] This application has at least the following beneficial effects: The automatic tensioner and anti-skid chain assembly provided by this application can achieve the automatic tightening function of the ratchet by controlling the opening and closing of the wrench relative to the housing, thus realizing the automatic tightening function of the tensioner. It is very convenient and quick to use, saving the installation time of the anti-skid chain assembly and improving the user experience. Moreover, when the automatic tensioner provided by this application is tightening, the first end of its wrench is in contact with the housing. If the chain body needs to be disassembled, the wrench must be turned. The wrench design prevents the tensioner from being accidentally activated, improving the reliability of the tensioner and avoiding the problem of the chain body falling off during use, thereby improving the safety performance of the anti-skid chain assembly. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of the automatic tightening device according to an embodiment of this application.

[0017] Figure 2 for Figure 1 An exploded view of the automatic tightening device.

[0018] Figure 3 This is a schematic diagram of the ratchet structure according to an embodiment of this application.

[0019] Figure 4 This is a schematic diagram of the internal structure of the automatic tightener according to an embodiment of this application after removing part of the housing.

[0020] Figure 5 This is a schematic diagram of the structure of the wrench according to an embodiment of this application.

[0021] Figure 6 This is a schematic diagram of the internal structure of a portion of the housing in an embodiment of this application.

[0022] Figure 7 This is a schematic diagram of the connecting rod structure according to an embodiment of this application.

[0023] Figure 8 This is a schematic diagram of the slider structure according to an embodiment of this application.

[0024] Figure 9 for Figure 1 A structural schematic diagram of the automatic tightener from another perspective.

[0025] Figure 10 This is a schematic diagram of the installation structure of the anti-skid chain assembly according to an embodiment of this application.

[0026] The meanings of the labels in the attached diagram are as follows: 100. Automatic tensioner; 1. Handle; 11. Connecting part; 2. Steel cable; 3. Housing; 31. Second stop; 32. Third stop; 33. Receiving cavity; 331. Side plate; 332. Guide groove; 34. Snap-fit ​​part; 35. Sliding groove; 36. Receiving groove; 37. Connecting hole; 38. Top cover; 4. Wrench; 41. First stop; 42. Force application part; 421. Anti-slip part; 43. Connecting part; 44. Cam part; 45. Hook; 46. First end; 47. Second end; 5. Ratchet; 51. First ratchet tooth; 52. Second ratchet tooth; 53. Mounting cavity; 6. First check valve assembly; 61. Connecting rod; 62. First pawl; 63. First reset device; 64. Receiving hole; 7. Second check valve assembly; 71. Slider; 711. Protrusion; 712. Shoulder; 72. Second pawl; 8. Energy storage coil spring; 101. Chain body; 200. Tires. Detailed Implementation

[0027] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to limit the ways in which this application may be implemented. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0029] In the description of this application, it should be understood that the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are used only for the convenience of describing this application and 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, and therefore should not be construed as a limitation on this application. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0030] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0031] Please see Figures 1 to 4 The automatic tightener 100 of this application embodiment includes a housing 3, a ratchet 5, a wrench 4, a first check valve assembly 6, and a second check valve assembly 7. The ratchet 5 is disposed inside the housing 3 and rotatably connected to it. A first ratchet portion 51 and a second ratchet portion 52 are respectively provided on the circumferential wall of the ratchet 5, and the first ratchet portion 51 and the second ratchet portion 52 are arranged side-by-side along the axial direction of the ratchet 5. That is, the first ratchet portion 51 and the second ratchet portion 52 are coaxially arranged and can be fixedly connected or integrally formed. The first ratchet portion 51 and the second ratchet portion 52 are respectively provided with a plurality of ratches along the circumferential direction. The wrench 4 includes a first end 46 disposed outside the housing 3 and a second end 47 disposed inside the housing 3. The wrench 4 rotates relative to the housing 3, causing the first end 46 to move away from the housing 3, so that the second end 47 drives the first check valve assembly 6 and the second check valve assembly 7, causing the first check valve assembly 6 to separate from the first ratchet portion 51, and causing the second check valve assembly 7 and the second ratchet portion 52 to engage, thereby enabling the ratchet 5 to rotate along a first direction A. When the ratchet 5 rotates in the first direction A, it loosens the chain body 101. The second check valve assembly 7 prevents the ratchet 5 from rotating in the second direction when the chain body 101 needs to be loosened, such as during disassembly. The ratchet wrench 4 rotates relative to the housing 3, causing its first end 46 to engage with the housing 3. The first check valve assembly 6 engages with the first ratchet tooth 51, and the second check valve assembly 7 disengages from the second ratchet tooth 52, allowing the ratchet 5 to rotate in the second direction. When the ratchet 5 rotates in the second direction, it tightens the chain body 101. The first check valve assembly 6 prevents the ratchet 5 from rotating in the first direction A when the chain body 101 needs to be tightened, such as during installation. The first direction A and the second direction are opposite; for example, if the first direction A is counterclockwise, then the second direction is clockwise.

[0032] Specifically, such as Figure 4 and Figure 5As shown, in some embodiments, the wrench 4 is a one-piece molded part, including a connecting part 43 and a force-applying part 42 and a cam part 44 respectively provided at both ends of the connecting part 43. The force-applying part 42 is provided at the first end 46 of the wrench 4, and the cam part 44 is provided at the second end 47 of the wrench 4. One end of the connecting part 43 extends outward and upward to form the force-applying part 42. The force-applying part 42 is curved upward relative to the connecting part 43 to form a force-applying space, so as to facilitate the operation of the wrench 4. The surface of the force-applying part 42 near the housing 3 is also provided with an anti-slip part 421, which can prevent slippage when applying force. The anti-slip part 421 can be, for example, multiple parallel ridges or other uneven structures. The other end of the connecting part 43 extends into the housing 3 to form the cam part 44, which is used to drive the first check valve assembly 6 and the second check valve assembly 7. The automatic tightener 100 of this application embodiment can simultaneously drive the first check component 6 and the second check component 7 by pulling the wrench 4 once, which simplifies the overall structure of the tightener and makes it easy to operate.

[0033] Furthermore, such as Figure 5 and Figure 6 As shown, a hook 45 can also be provided on the wrench 4, and a locking part 34 that cooperates with the hook 45 can be provided on the outer wall of the housing 3. The hook 45 can be located near the end of the connecting part 43 close to the force-applying part 42. The cross-section of the hook 45 is an inverted triangle. The tip of the hook 45 can lock the protruding locking part 34 on the outer wall of the housing 3, so that the wrench 4 can fit against the outer wall of the housing 3 and be firmly fixed to the housing 3 when no driving force is applied to the first check valve assembly 6 and the second check valve assembly 7. This prevents the chain body 101 from slipping off due to accidental contact when the automatic tensioner 100 is performing the tightening function, thus improving the safety of the anti-skid chain assembly.

[0034] Furthermore, such as Figures 4 to 6As shown, the second end 47 of the wrench 4 has a protruding first stop 41, and the inner wall of the housing 3 has a corresponding protruding second stop 31. The first stop 41 and the second stop 31 work together to keep the first end 46 of the wrench 4 away from the housing 3. When the first end 46 of the wrench 4 rotates from the position closest to the outer wall of the housing 3 to the position furthest from the outer wall of the housing 3, the cam part 44 drives the first check assembly 6 and the second check assembly 7. This operation is to loosen the chain body 101 or stretch the steel cable 2 of the automatic tensioner 100 to connect it to the chain body 101. At this time, the first stop 41 rotates from one side of the second stop 31 to the other side and is blocked by the second stop 31 on that side to prevent the wrench 4 from rotating back. In this position, the cam part 44 of the wrench 4 always drives the first check assembly 6 and the second check assembly 7, which can easily realize the function of stretching the steel cable 2 outward without having to hold the wrench 4 down, making the operation more convenient. To prevent the first stop 41 of the wrench 4 from slipping out of the groove 35 of the housing 3 when the wrench 4 is in contact with the housing 3, a third stop 32 is provided at the other end of the groove 35. That is, the second stop 31 and the third stop 32 are respectively provided at both ends of the groove 35. The first stop 41 slides along the groove 35. When the first stop 41 crosses the groove 35 to the other side of the second stop 31, the second stop 31 plays a role in reversing and fixing the wrench 4.

[0035] like Figure 4 and Figure 7As shown, in some embodiments, the first check valve assembly 6 includes a connecting rod 61 and a first reset device 63. The middle portion of the connecting rod 61 is rotatably connected to the housing 3. The cam portion 44 is used to drive one end of the connecting rod 61 to separate the first pawl 62 and the first ratchet portion 51. The other end of the connecting rod 61 is provided with the first reset device 63 and the first pawl 62 on both sides respectively. The first reset device 63 is used to drive the other end of the connecting rod 61 to engage the first pawl 62 and the first ratchet portion 51. The middle portion of the connecting rod 61 is rotatably connected to the inner wall of the housing 3 via a rotating shaft. The end of the connecting rod 61 away from the cam portion 44 is provided with the first pawl 62 and the first reset device 63. The first pawl 62 is located on the side of the connecting rod 61 near the ratchet 5, and the first reset device 63 is located on the side of the connecting rod 61 away from the ratchet 5. The first pawl 62 may include one or more protruding claw-like structures. The first pawl 62 is used to engage or disengage with the first ratchet portion 51. The first reset device 63 can be an elastic element such as a spring. The side of the connecting rod 61 away from the ratchet 5 is provided with a receiving hole 64, and the housing 3 is provided with a receiving groove 36. One end of the spring is inserted into the receiving hole 64 and the other end is inserted into the receiving groove 36, so that when the cam applies a driving force to the connecting rod 61, the end of the connecting rod 61 away from the cam applies a compressive force to the spring due to rotation. When the cam no longer applies a driving force to the connecting rod 61, the potential energy of the spring is released, and the first pawl 62 driving the connecting rod 61 is inserted into the tooth groove of the first ratchet 51 to prevent the ratchet 5 from rotating in the opposite direction when the automatic tightener 100 realizes the tightening function.

[0036] like Figure 2 , Figure 4 and Figure 8As shown, in some embodiments, the second check component 7 includes a slider 71 and a second reset device (not shown). At one end of the slider 71 away from the cam portion 44, there is a second pawl 72. On the inner wall of the housing 3, there is a receiving cavity 33. A guide groove 332 is formed on the receiving cavity 33. The cam portion 44 is used to drive the slider 71 to move towards the ratchet wheel 5, so that the second pawl 72 extends out of the receiving cavity 33 along the guide groove 332 and engages with the second ratchet portion 52. The second reset device is used to drive the slider 71 to move away from the ratchet wheel 5, so that the second pawl 72 enters the receiving cavity 33 along the guide groove 332 and disengages from the second ratchet portion 52. Specifically, on the inner wall of the housing 3, there is a receiving cavity 33 surrounded by a plurality of protruding side plates 331. The guide groove 332 is formed on the side plate 331 close to the ratchet wheel 5. The slider 71 is generally in a shape similar to a "convex", including a protruding portion 711 in the middle and two shoulders 712 respectively provided on the protruding portion 711. The second pawl 72 is installed at the front end (the end close to the ratchet wheel 5) of the protruding portion 711. The second pawl 72 can extend outwards from the receiving cavity 33 through the guide groove 332, and the other parts of the slider 71 are all located in the receiving cavity 33. There is a top cover 38 above the receiving cavity 33 to prevent the second pawl 72 from slipping off from above the receiving cavity 33. The second reset device can be, for example, a spring. Each of the two shoulders 712 of the second pawl 72 is provided with a receiving hole 64, and a spring is inserted into each receiving hole 64. The other end of the spring abuts against the inner wall of the receiving side plate 331. When the cam portion 44 applies a driving force to the first pawl 62, the two shoulders 712 compress the spring, causing the pawl portion to extend out of the receiving cavity 33. When the cam portion 44 no longer applies a driving force to the pawl, the spring resets and pushes the two shoulders 712 to move towards the inside of the receiving cavity 33. Both the first check component 6 and the second check component 7 are driven by the wrench 4 to realize the rotation of the ratchet wheel 5 in the first direction A, and the rotation of the ratchet wheel 5 in the second direction is realized respectively through the driving of the first reset device 63 and the second reset device. The overall structure is simple, reliable and easy to operate.

[0037] As Figure 2 , Figure 4 and Figure 9As shown, the automatic tensioner 100 of this embodiment also includes a steel cable 2. One end of the steel cable 2 is fixed to the ratchet 5, and the other end of the steel cable 2 is connected to a handle 1. The handle 1 is located outside the housing 3. The steel cable 2 is used to wind around the outer peripheral wall of the ratchet 5 between the first ratchet portion 51 and the second ratchet portion 52. Pulling the handle 1 outward drives the ratchet 5 to rotate in the first direction A. Pulling the steel cable 2 enables the ratchet 5 to rotate in the first direction A. Pulling the steel cable 2 to a certain length facilitates the connection between the automatic tensioner 100 and the chain body 101. After the steel cable 2 is connected to the chain body 101, the ratchet 5 can be controlled to rotate in the second direction, thereby tightening the chain body 101. To facilitate the operation of pulling the steel cable 2, a handle 1 can be provided at the end of the steel cable 2. One end of the handle 1 is fixedly connected to the steel cable 2, and the other end is provided with a connecting structure 11, which can be used to connect with the chain body 101. The specific structure of connection structure 11 is not limited; for example, it can be a connecting ring, etc.

[0038] like Figure 2 and Figure 3 As shown, the automatic tensioner 100 of this embodiment also includes an energy-storing coil spring 8. The ratchet 5 has a mounting cavity 53, and the energy-storing coil spring 8 is installed in the mounting cavity 53. One end of the energy-storing coil spring 8 is fixedly connected to the ratchet 5, and the other end is fixedly connected to the housing 3. The energy-storing coil spring 8 is used to drive the ratchet 5 to rotate in the second direction. Pulling the steel cable 2 can provide the power for the ratchet 5 to rotate in the first direction A, and the energy-storing coil spring 8 is used to provide the power for the ratchet 5 to rotate in the second direction. The energy-storing coil spring 8 is installed in the mounting cavity 53 of the ratchet 5. When the handle 1 is pulled to make the ratchet 5 rotate in the first direction A, the energy-storing coil spring 8 stores energy. When the handle 1 is released and the wrench 4 is rotated to make the driving end of the cam part 44 move away from the first check assembly 6 and the second check assembly 7, the energy-storing coil spring 8 releases energy and drives the ratchet 5 to rotate in the second direction.

[0039] like Figure 9 and Figure 10 As shown, this application embodiment also provides a snow chain assembly for installation on a vehicle tire 200. The snow chain assembly of this embodiment includes a chain body 101 and an automatic tensioner 100 as described in the previous embodiment, with the automatic tensioner 100 connected to the chain body 101. For ease of disassembly and storage, the automatic tensioner 100 can be detachably connected to the chain body 101.

[0040] In some embodiments, one or more connecting holes 37 may be provided on the outer peripheral wall of the housing 3, for example, two connecting holes 37 may be provided. The number and position of the connecting structure 11 and the connecting holes 37 correspond to the installation position of the chain body. The connecting structure 11 and the connecting holes 37 may be hole structures through which connectors can pass, or connector structures that can be directly used to connect with the chain body, such as hooks with locking structures.

[0041] The automatic tensioner and anti-skid chain assembly provided in this application have the advantages of simple structure, automatic tensioning, and reliable structure. They can realize the rapid installation of the anti-skid chain assembly and are convenient and quick to operate.

[0042] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0043] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An automatic tightening device, characterized in that, The device includes a housing, a ratchet, a wrench, a first check valve assembly, and a second check valve assembly. The ratchet is disposed within the housing and rotatably connected to it. A first ratchet portion and a second ratchet portion are respectively provided on the circumferential wall of the ratchet, and the first and second ratchet portions are arranged side-by-side along the axial direction of the ratchet. The wrench includes a first end disposed outside the housing and a second end disposed inside the housing. The wrench rotates relative to the housing, causing the first end to move away from the housing, so that the second end drives the first and second check valve assemblies, causing the first check valve assembly to disengage from the first ratchet portion and the second check valve assembly to engage with the second ratchet portion, thereby enabling the ratchet to rotate in a first direction. Alternatively, the wrench rotates relative to the housing, causing the first end to contact the housing, the first check valve assembly to engage with the first ratchet portion, and the second check valve assembly to disengage from the second ratchet portion, so that the ratchet can rotate in a second direction, where the first and second directions are opposite.

2. The automatic tightening device as described in claim 1, characterized in that, The wrench includes a connecting part and a force-applying part and a cam part respectively disposed at both ends of the connecting part. The force-applying part is disposed at the first end of the wrench, and the cam part is disposed at the second end of the wrench.

3. The automatic tightening device as described in claim 2, characterized in that, The wrench is provided with a hook, and the outer wall of the housing is provided with a snap-fit ​​part that cooperates with the hook.

4. The automatic tightening device as described in claim 2, characterized in that, The second end of the wrench is provided with a protruding first stop, and the inner wall of the housing is provided with a corresponding protruding second stop. The first stop and the second stop are used in conjunction to keep the first end of the wrench away from the housing.

5. The automatic tightening device as described in claim 2, characterized in that, The first check valve assembly includes a connecting rod and a first reset device. The middle part of the connecting rod is rotatably connected to the housing. The cam part is used to drive one end of the connecting rod to separate the first pawl and the first ratchet. The other end of the connecting rod is provided with the first reset device and the first pawl on both sides respectively. The first reset device is used to drive the other end of the connecting rod to engage the first pawl and the first ratchet.

6. The automatic tightening device as described in claim 2, characterized in that, The second check valve assembly includes a slider and a second reset device. The slider has a second pawl at one end away from the cam portion. The inner wall of the housing has a receiving cavity with a guide groove. The cam portion drives the slider to move towards the ratchet, so that the second pawl extends out of the receiving cavity along the guide groove and engages with the second ratchet tooth. The second reset device drives the slider to move away from the ratchet, so that the second pawl enters the receiving cavity along the guide groove and disengages from the second ratchet tooth.

7. The automatic tightening device as described in claim 1, characterized in that, It also includes a steel cable, one end of which is fixed to the ratchet, and the other end of which is connected to a handle. The handle is located outside the housing. The steel cable is used to wrap around the ratchet between the first ratchet tooth and the second ratchet tooth. Pulling the handle outwards drives the ratchet to rotate in the first direction.

8. The automatic tightening device as described in claim 1, characterized in that, It also includes an energy-storing coil spring. The ratchet has a mounting cavity, and the energy-storing coil spring is installed in the mounting cavity. One end of the energy-storing coil spring is fixedly connected to the ratchet, and the other end is fixedly connected to the housing. The energy-storing coil spring is used to drive the ratchet to rotate in the second direction.

9. An anti-skid chain assembly, characterized in that, It includes a chain body and an automatic tensioner as described in any one of claims 1 to 9, wherein the automatic tensioner is connected to the chain body.

10. The anti-skid chain assembly as described in claim 9, characterized in that, The housing has at least one connection hole, the ratchet has a handle, the handle has a connecting part, and the connection hole and the connecting part are respectively used to connect to the chain body.

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