Safety belt detection device and safety belt

Abstract

The utility model discloses a safety belt detection device and a safety belt, and relates to the field of safety protection equipment, the safety belt detection device is used for detecting the wearing state of the safety belt, the safety belt comprises a first safety rope and a safety hook, and the safety hook is respectively connected with the first safety rope and the safety belt detection device; the safety belt detection device includes: a housing; the detection window is arranged on the surface of the shell, a distance sensor is embedded in the detection window, and the detection direction of the distance sensor faces a human body; the processor is arranged in the shell, the first end of the processor is connected with the first end of the distance sensor, and the distance sensor is used for detecting the distance relative to the human body so that the processor can determine whether the safety belt is in a worn state or not according to the distance. And the detection accuracy and reliability are improved.

Description

Technical Field

[0001] This utility model relates to the field of safety protection equipment, and in particular to a seat belt detection device and a seat belt. Background Technology

[0002] Safety belts, as basic safety protection equipment in high-altitude operations and construction, provide reliable restraint in the event of an accidental fall, effectively reducing the risk of injury. However, due to inconvenience or a sense of complacency, some workers often carelessly hang the safety hook back on their body or place it at their side, thus negating the protective function of the safety hook and leading to serious fall accidents.

[0003] To determine whether workers are wearing safety belts correctly, existing technologies mostly use infrared sensors to detect the proximity of the safety hook 6 to the human body. That is, by detecting whether there is an infrared frequency band at the human body's normal temperature (e.g., 37°C) within the detection range, the wearing status of the safety hook is determined. However, this method is only suitable for indoor environments. In outdoor high-altitude work scenarios, because the ambient temperature is similar to the human body temperature and is affected by factors such as sunlight, surrounding heat sources, and dust, the infrared sensor is prone to false alarms or missed alarms, resulting in low detection accuracy and reliability. Summary of the Invention

[0004] This invention provides a seat belt detection device and a seat belt to solve the technical problem of low accuracy and reliability in detecting the wearing status of seat belts.

[0005] In a first aspect, a seat belt detection device is provided for detecting the wearing status of a seat belt, wherein the seat belt includes a first safety rope and a safety hook, and the safety hook is connected to the first safety rope and the seat belt detection device respectively;

[0006] The seat belt detection device includes:

[0007] case;

[0008] A detection window is provided on the surface of the housing, and a distance sensor is embedded in the detection window. The detection direction of the distance sensor is towards the human body.

[0009] A processor is disposed within the housing, with its first end connected to the first end of a distance sensor. The distance sensor is used to detect the distance relative to the human body, so that the processor determines whether the seat belt is being worn based on the distance.

[0010] In one embodiment, the detection window includes a first detection window and a second detection window that are disposed opposite to each other, and the distance sensor includes a first distance sensor and a second distance sensor;

[0011] The first detection window contains the first distance sensor, and the first detection window also contains the second distance sensor.

[0012] In one embodiment, the seatbelt detection device further includes a warning device;

[0013] The warning device is disposed inside and / or on the surface of the housing, and a first end of the warning device is connected to a second end of the processor.

[0014] In one embodiment, the warning device includes colored lights and / or a buzzer.

[0015] In one embodiment, the seatbelt detection device further includes a power module, a charging interface, and a storage module;

[0016] The charging interface is disposed on the surface of the housing;

[0017] The first end of the power module is connected to the first end of the charging interface, the second end of the power module is connected to the third end of the processor, the third end of the power module is connected to the second end of the distance sensor, the fourth end of the power module is connected to the second end of the warning device, the fifth end of the power module is connected to the first end of the storage module, and the second end of the storage module is connected to the fourth end of the processor.

[0018] In a second aspect, a safety belt is provided, the safety belt including a first safety rope, a safety hook and the safety belt detection device described in the first aspect;

[0019] The safety hook is connected to the first safety rope and the safety belt detection device, respectively.

[0020] In one embodiment, the safety hook includes a hook-shaped portion and a connecting portion;

[0021] The hook-shaped portion and the connecting portion are integrally formed;

[0022] The hook-shaped part is connected to the first safety rope, and the connecting part is connected to the safety belt detection device.

[0023] In one embodiment, the safety belt further includes a connecting loop and a second safety rope;

[0024] The connecting ring is movably sleeved on the first safety rope;

[0025] The hook-shaped part is connected to the first safety rope via the connecting ring, and the connecting part is connected to the safety belt detection device via the second safety rope.

[0026] In one embodiment, the connecting ring includes a D-shaped ring and a circular ring.

[0027] In one embodiment, the safety hook further includes a connecting mechanism and a hook rod, the hook rod including a locking part and an operating end;

[0028] The locking part is integrally formed with the operating end;

[0029] The connecting mechanism is disposed in the stress zone of the hook-shaped portion;

[0030] The first locking end of the locking part is pivotally connected to the connecting mechanism, and the second locking end is fixedly connected to the hook-shaped part. In the closed position, the operating end abuts against the opening end of the hook-shaped part to close the opening of the hook-shaped part.

[0031] The beneficial effects of the technical solution provided by this utility model are as follows: By setting a detection window on the surface of the housing of the seat belt detection device and setting a distance sensor inside the housing, and setting the detection direction of the distance sensor, the distance sensor can measure the distance towards the human body and work in conjunction with the processor. This allows the processor to accurately determine whether the safety hook is close to the wearer's body based on the distance detected by the distance sensor. That is, by utilizing the characteristic that the safety hook is always parallel to the human body when it is hooked back, it can determine whether the wearer is in a wearing state. Compared with traditional technology, its non-contact distance measurement principle is not affected by factors such as ambient temperature, sunlight, surrounding heat sources, and dust, which improves detection accuracy, avoids misjudgment or missed judgment, and improves detection accuracy and reliability. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of a seat belt in one embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of a seat belt detection device in one embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of a safety hook in one embodiment of the present invention.

[0036] The labels for the attached figures are as follows:

[0037] 1-First detection window; 2-Second detection window; 3-Seat belt detection device; 4-Second safety rope; 5-Connecting ring;

[0038] 6-Safety hook; 61-Hook-shaped part; 62-Connecting part; 63-Connecting mechanism; 631-Arc-shaped opening; 64-Hook rod; 641-Locking part; 6411-First locking end; 6412-Second locking end; 642-Operating end;

[0039] 7-First safety rope; 8-Distance sensor; 9-Processor; 10-Warning device; 11-Power module; 12-Charging interface; 13-Storage module. Detailed Implementation

[0040] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present utility model.

[0041] To facilitate understanding of the embodiments of this utility model, other prior art involved in this utility model will be introduced as follows:

[0042] The first method uses Near Field Communication (NFC) to detect whether the safety hook is close to the human body. The basic principle is to place an NFC transmitter and receiver at opposite ends of the body and the safety hook. When the transmitter approaches the receiver, the receiver detects the transmitter's energy and establishes communication, thus determining that the safety hook is back on the body. However, NFC is a near-field communication technology, requiring the transmitter and receiver to be very close to communicate. This means that to detect the possible attachment points of the safety hook on the body, NFC devices would need to be placed over a large area, or even all over, of the body, which is impractical and extremely expensive.

[0043] The second method uses visual judgment to determine whether the safety hook is back on the body. The basic principle is to install a camera on the safety hook and use the video images captured by the camera, combined with algorithms, to determine whether the person in the camera's view is close to the hook. However, in actual high-altitude work scenarios, the position and angle of the safety hook, the brightness of the ambient light, and the material and color of the worker's clothing are complex and diverse factors that cannot guarantee the correct implementation of the algorithm.

[0044] The other methods mentioned above would lead to increased manufacturing costs of seat belts and problems with proper implementation. This invention, however, addresses these issues by setting a detection window on the surface of the seat belt detection device's housing and housing a distance sensor 8 within the housing. The detection direction of the distance sensor 8 is set so that it can measure distances towards the human body. Working in conjunction with a processor 9, the processor 9 can accurately determine whether the safety hook 6 is close to the wearer's body based on the distance detected by the distance sensor 8. That is, by utilizing the characteristic that the safety hook 6 is always parallel to the body when hooked back, it determines whether the belt is being worn. This simplifies the detection conditions, reducing the influence of environmental temperature, sunlight, surrounding heat sources, and dust, improving detection accuracy, avoiding false positives or false negatives, and enhancing detection accuracy and reliability. Furthermore, it is lower in cost and easier to implement.

[0045] Please refer to the following as well. Figures 1 to 3 The following description provides a detailed explanation of the structure and steps of the technical solution proposed in this utility model.

[0046] Firstly, such as Figure 1 and Figure 2 As shown, a seat belt detection device 3 is provided for detecting the wearing status of a seat belt. The seat belt includes a first safety rope 7 and a safety hook 6, the safety hook 6 being connected to both the first safety rope 7 and the seat belt detection device 3. The seat belt detection device 3 includes: a housing; a detection window disposed on the surface of the housing, the detection window embedding a distance sensor 8, the detection direction of the distance sensor 8 being towards the human body; and a processor 9 disposed within the housing, the first end of the processor 9 being connected to the first end of the distance sensor 8, the distance sensor 8 being used to detect the distance relative to the human body, so that the processor 9 determines whether the seat belt is being worn based on the distance.

[0047] In this embodiment, the distance sensor 8 may include, but is not limited to, a laser rangefinder, an infrared rangefinder, and other distance sensors.

[0048] As an example, the safety belt detection device 3 is connected to both the first safety rope 7 and the safety hook 6, with the first safety rope 7 fixed to the worker's waist. The safety belt detection device 3 includes a housing, a processor 9 (e.g., an MCU) installed within the housing, and a detection window on the surface of the housing. A distance sensor 8 is embedded within the detection window. The first end of the distance sensor 8 can be connected to the first end of the processor 9 via a data cable (e.g., an I2C bus). When the processor 9 receives a measurement from the distance sensor 8 indicating that the distance between the safety hook 6 and the human body is less than a preset threshold, it determines that the safety hook 6 is hooked back onto the human body. That is, by utilizing the characteristic that the safety hook 6 is always parallel to the human body when hooked back, it determines that the safety belt is in a wearing state, thereby achieving real-time and accurate detection of the safety belt wearing status. Compared to traditional technologies, its non-contact distance measurement principle is unaffected by environmental temperature, sunlight, surrounding heat sources, and dust, improving detection accuracy, avoiding false or missed detections, and enhancing detection accuracy and reliability.

[0049] In one embodiment, the detection window includes a first detection window 1 and a second detection window 2 arranged opposite to each other, and the distance sensor 8 includes a first distance sensor 8 and a second distance sensor 8; the first detection window 1 is embedded with the first distance sensor 8, and the first detection window 1 is embedded with the second distance sensor 8.

[0050] As an example, the housing of the seat belt detection device 3 includes four sides, wherein the first side and the third side are opposite sides, and the second side and the fourth side are opposite sides. Therefore, the first detection window 1 can be placed on the first side and the second detection window 2 on the third side, or the first detection window 1 can be placed on the second side and the second detection window 2 on the fourth side. No limitation is made here, but it should be understood that because the safety hook 6 is parallel to the first detection window 1 and the second detection window 2, in actual use, the human body is also parallel to either detection window, thus ensuring that the detection direction of the distance sensor 8 is towards the human body.

[0051] The first distance sensor 8 is disposed in the first detection window 1, and the second distance sensor 8 is disposed in the second detection window 2. Both the first distance sensor 8 and the second distance sensor 8 can be connected to the processor 9 via a data cable (e.g., an I2C bus) so that the processor 9 can determine the wearing status of the seat belt based on the distance detected by the first distance sensor 8 or the second distance sensor 8.

[0052] It should be understood that the present invention preferably uses two detection windows. As long as the detection distance of one detection window meets the preset conditions, for example, when the distance is less than a preset threshold (e.g., 1cm), it can be determined that the safety hook 6 is hooked back onto the human body, that is, it can be determined that the safety belt is in the wearing state.

[0053] It should be noted that the aforementioned distance sensor 8 may include one, three, or four, and no limitation is made here. For example, when there are four distance sensors 8, one distance sensor 8 can be installed in the detection window on each of the four sides of the housing of the seat belt detection device 3, thereby improving detection accuracy and making it applicable to more scenarios.

[0054] In one embodiment, the seat belt detection device 3 further includes a warning device 10; the warning device 10 is disposed inside and / or on the surface of the housing, and a first end of the warning device 10 is connected to a second end of the processor 9.

[0055] As an example, the first end of the warning device 10 can be connected to the second end of the processor 9 via a data line (e.g., an I2C bus). The warning device 10 may include, but is not limited to, colored lights and / or a buzzer; the colored lights may be disposed on the surface of the housing to emit a visible flashing light signal; the buzzer may be disposed inside the housing or on the surface to emit an acoustic warning signal; when the processor 9 determines that the distance to the safety hook 6 is greater than a preset threshold, the processor 9 can drive the colored lights to flash and / or the buzzer to sound to remind the worker that the safety belt is incorrectly fastened or not fastened.

[0056] In one embodiment, the seat belt detection device 3 further includes a power module 11, a charging interface 12, and a storage module 13; the charging interface 12 is disposed on the surface of the housing; a first end of the power module 11 is connected to the first end of the charging interface 12, a second end of the power module 11 is connected to the third end of the processor 9, a third end of the power module 11 is connected to the second end of the distance sensor 8, a fourth end of the power module 11 is connected to the second end of the warning device 10, a fifth end of the power module 11 is connected to the first end of the storage module 13, and a second end of the storage module 13 is connected to the fourth end of the processor 9.

[0057] As an example, the charging interface 12 can be located on the surface of the housing (e.g., the bottom or top surface of the housing), and the first end of the charging interface 12 is connected to the first end of the power module 11 for charging the power module 11; the second end of the power module 11 is connected to the third end of the processor 9 for providing power to the processor 9; the third end of the power module 11 is connected to the second end of the distance sensor 8 for ensuring the normal operation of the distance sensor 8; the fourth end of the power module 11 is electrically connected to the second end of the warning device 10 for providing power to the warning device 10; the fifth end of the power module 11 is connected to the first end of the storage module 13 for providing power to the storage module 13, ensuring the continuity and reliability of data recording, which helps in subsequent retrospective analysis and management of the seat belt usage status; the second end of the storage module 13 is connected to the fourth end of the processor 9 for storing the data processed by the processor 9 and / or information such as wearing status, which are not limited here. Through the above settings, the independent power supply and long-term operation capability of the seat belt detection device 3 are ensured, meeting the status monitoring and safety management needs in long-term operation scenarios.

[0058] Secondly, such as Figures 1 to 3 As shown, a safety belt is provided, the safety belt including a first safety rope 7, a safety hook 6 and the safety belt detection device 3 described in the first aspect above; the safety hook 6 is connected to the first safety rope 7 and the safety belt detection device 3 respectively.

[0059] In summary, by installing the seat belt detection device 3 described in the first aspect on the seat belt, it is possible to accurately determine whether the safety hook 6 is close to the wearer's body. That is, by utilizing the characteristic that the safety hook 6 is always parallel to the body when it is hooked back, it is possible to determine whether the wearer is wearing the seat belt. Compared with traditional technology, its non-contact distance measurement principle is not affected by factors such as ambient temperature, sunlight, surrounding heat sources, and dust, which improves the detection accuracy, avoids misjudgment or missed judgment, and improves the accuracy and reliability of detection.

[0060] It should be noted that the above-mentioned limitations on seat belts can be referred to the limitations of the seat belt detection device 3 described in the first aspect above. To avoid repetition, they will not be repeated here.

[0061] In one embodiment, the safety hook 6 includes a hook-shaped portion 61 and a connecting portion 62; the hook-shaped portion 61 and the connecting portion 62 are integrally formed; the hook-shaped portion 61 is connected to the first safety rope 7, and the connecting portion 62 is connected to the safety belt detection device 3.

[0062] As an example, the safety hook 6 can be made of a rigid material (e.g., aluminum alloy or iron) or stainless steel; this is merely an example and does not constitute a limitation. The safety hook 6 can be integrally formed from a hook-shaped portion 61 and a connecting portion 62. The hook-shaped portion 61 can be a C-shaped structure with a preset opening diameter (e.g., 20 cm), and its inner surface can have anti-slip textures. The connecting portion 62 can be a circular or rectangular hole. The hook-shaped portion 61 is connected to the first safety rope 7, for example, by detachably fastening the hook-shaped portion 61 to the first safety rope 7; the connecting portion 62 is connected to the safety belt detection device 3, for example, by connecting the safety belt detection device 3 to the connecting portion 62 via a rope. It should be understood that the above is merely an example and does not constitute a limitation of this utility model.

[0063] In one embodiment, the safety belt further includes a connecting ring 5 and a second safety rope 4; the connecting ring 5 is movably sleeved on the first safety rope 7; the hook-shaped part 61 is connected to the first safety rope 7 through the connecting ring 5, and the connecting part 62 is connected to the safety belt detection device 3 through the second safety rope 4.

[0064] As an example, the connecting ring 5 may include, but is not limited to, a D-shaped ring or a circular ring. The connecting ring 5 is fitted onto the first safety rope 7 and can slide freely along the first safety rope 7. The hook-shaped portion 61 of the safety hook 6 can be hooked onto the connecting ring 5, thereby connecting the safety hook 6 to the first safety rope 7. When the worker moves or adjusts their posture, the safety hook 6 can rotate with the connecting ring 5 and always remain parallel to the human body, thus cooperating with the safety detection device 3 to accurately monitor the close-fitting status of the safety hook 6. The connecting portion 62 can be connected to the safety belt detection device 3 via the second safety rope 4. For example, one end of the second safety rope 4 can be fixed to a circular hole, thereby fixing the safety belt detection device 3 to the safety rope, or other methods can be used for connection, which are not limited here. The first safety rope 7 and the second safety rope 4 may include, but are not limited to, synthetic fiber ropes or other safety ropes, which are not limited here.

[0065] In one embodiment, such as Figure 3 As shown, the safety hook 6 further includes a connecting mechanism 63 and a hook rod 64. The hook rod 64 includes a locking part 641 and an operating end 642. The locking part 641 and the operating end 642 are integrally formed. The connecting mechanism 63 is disposed in the stress area of ​​the hook-shaped part 61. The first locking end 6411 of the locking part 641 is pivotally connected to the connecting mechanism 63, and the second locking end 6412 is fixedly connected to the hook-shaped part 61. In the closed position, the operating end 642 abuts against the open end of the hook-shaped part 61 to close the opening of the hook-shaped part 61.

[0066] As an example, the safety hook 6 also includes a connecting mechanism 63 and a hook rod 64. The hook rod 64 includes a locking part 641 and an operating end 642; wherein, the locking part 641 and the operating end 642 are integrally formed; the connecting mechanism 63 can be fixed to the stress area provided in the hook-shaped part 61 by welding or connecting parts, and the connecting mechanism 63 is provided with an arc-shaped opening 631. The first locking end 6411 of the locking part 641 is pivotally connected to the arc-shaped opening 631 of the connecting mechanism 63, that is, the first locking end 6411 can move along the arc-shaped opening 631, and the second locking end 6411 is pivotally connected to the first locking end 6411 of the locking part 641. End 6412 can also be fixedly connected to hook-shaped part 61 by welding or connecting parts, such as rivets, locating pins, and bolt assemblies. In the closed position, operating end 642 automatically abuts against the open end of hook-shaped part 61 under the push of the pre-tension spring in connecting mechanism 63 to close the opening of hook-shaped part 61, thereby locking the safety hook 6. When it is necessary to open the safety hook 6, the operator can press operating end 642 to compress the pre-tension spring in connecting mechanism 63 and move it along the arc-shaped opening 631, thereby opening the safety hook 6. It should be understood that the above is only an example of a safety hook 6 and does not constitute a limitation of this utility model.

[0067] In the description of this utility model, "multiple" refers to two or more.

[0068] In the description of this utility model, the terms "longitudinal," "radial," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used solely for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0069] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0070] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. A seat belt detection device characterized by comprising: The device is used to detect the wearing status of a seat belt. The seat belt includes a first safety rope and a safety hook, and the safety hook is connected to the first safety rope and the seat belt detection device, respectively. The seat belt detection device includes: case; A detection window is provided on the surface of the housing, and a distance sensor is embedded in the detection window. The detection direction of the distance sensor is towards the human body. A processor is disposed within the housing, the first end of which is connected to the first end of the distance sensor, the distance sensor being used to detect the distance relative to the human body, so that the processor determines whether the seat belt is being worn based on the distance.

2. The seat belt detection device according to claim 1, characterized by The detection window includes a first detection window and a second detection window that are set opposite to each other, and the distance sensor includes a first distance sensor and a second distance sensor; The first detection window contains the first distance sensor, and the first detection window also contains the second distance sensor.

3. The seat belt detection device of claim 1, wherein The seat belt detection device also includes a warning device; The warning device is disposed inside and / or on the surface of the housing, and a first end of the warning device is connected to a second end of the processor.

4. The belt detection apparatus according to claim 3, characterized by The warning device includes colored lights and / or a buzzer.

5. The belt detection apparatus according to claim 3 or 4, characterized by The seat belt detection device also includes a power module, a charging interface, and a storage module; The charging interface is disposed on the surface of the housing; The first end of the power module is connected to the first end of the charging interface, the second end of the power module is connected to the third end of the processor, the third end of the power module is connected to the second end of the distance sensor, the fourth end of the power module is connected to the second end of the warning device, the fifth end of the power module is connected to the first end of the storage module, and the second end of the storage module is connected to the fourth end of the processor.

6. A safety belt, characterized by The safety belt includes a first safety rope, a safety hook, and a safety belt detection device as described in any one of claims 1 to 5; The safety hook is connected to the first safety rope and the safety belt detection device, respectively.

7. The safety belt of claim 6, wherein The safety hook includes a hook-shaped part and a connecting part; The hook-shaped portion and the connecting portion are integrally formed; The hook-shaped part is connected to the first safety rope, and the connecting part is connected to the safety belt detection device.

8. The safety belt of claim 7, wherein, The safety belt also includes a connecting ring and a second safety rope; The connecting ring is movably sleeved on the first safety rope; The hook-shaped part is connected to the first safety rope via the connecting ring, and the connecting part is connected to the safety belt detection device via the second safety rope.

9. The safety belt of claim 8, wherein, The connecting ring includes a D-shaped ring and a circular ring.

10. The safety belt according to any one of claims 7 to 9, characterized in that The safety hook also includes a connecting mechanism and a hook rod, the hook rod including a locking part and an operating end; The locking part is integrally formed with the operating end; The connecting mechanism is disposed in the stress zone of the hook-shaped portion; The first locking end of the locking part is pivotally connected to the connecting mechanism, and the second locking end is fixedly connected to the hook-shaped part. In the closed position, the operating end abuts against the opening end of the hook-shaped part to close the opening of the hook-shaped part.

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