Special card holder for micro-column gel immunodetection card

Abstract

The invention discloses a special card support for a micro-column gel immunodetection card, which belongs to the field of medical instruments and comprises a first card support and a second card support detachably connected with the first card support, and the first card support and the second card support are components with the same structure; the first card holder further comprises supporting strips which are annularly, uniformly and fixedly connected to the outer surface of the lower connecting piece, one end of each supporting strip is fixedly connected with a centrifugal cylinder, the outer surfaces of the annularly distributed centrifugal cylinders are jointly and fixedly connected with a fixing ring, detection card slots are formed in the centrifugal cylinders, and micro-column gel detection cards are inserted into the centrifugal cylinders through the detection card slots. By means of the supporting strips and the fixing rings, the even number of centrifugal cylinders are annularly and evenly distributed, it can be guaranteed that the distance between each centrifugal cylinder and the rotating axis is the same, then it is guaranteed that the mass moment is the same, finally the centrifugal force is the same, the accuracy of the detection result is guaranteed, operation is convenient, and the detection efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and more particularly to a special card holder for microcolumn gel immunoassay cards. Background Art

[0002] The ABO, RhD Blood Typing Test Card (Microcolumn Gel Method) is an in vitro diagnostic biological product based on microcolumn gel immunoassay technology, primarily used to detect the human ABO blood group system and RhD antigens. This test card, with a microcolumn gel containing specific antibodies as its core component, determines blood typing by observing the agglutination reaction between red blood cells and antibodies after centrifugation. It features standardized procedures and intuitive results.

[0003] Before use, the microcolumn gel immunoassay card must be equilibrated to room temperature and visually inspected. The anticoagulated blood specimen must be prepared as a red blood cell suspension before being added to the test card wells. Centrifuge the specimen in a dedicated centrifuge in stages (900 rpm for 2 minutes, then 1500 rpm for 3 minutes). Results are graded based on agglutination intensity. Specimen quality and ambient temperature must be carefully controlled throughout the experiment to avoid interference from cold agglutination.

[0004] In the actual blood type detection process, a centrifugation step is required. The prior art mentions that a long strip card holder can be directly placed in a blood tester for centrifugal detection. The card holder in the prior art is usually long strip, such as a special card holder for microcolumn gel immunoassay card disclosed in Chinese patent announcement number CN222506328U. If it is placed directly in a centrifuge, the geometric asymmetry of the long strip card holder structure will lead to mass moment differences, further leading to differences in centrifugal force of the test cards at different positions, and ultimately leading to comparison errors in the test results. To solve this problem, it is also necessary to place the test cards symmetrically in partitions during centrifugation to ensure mass moment balance. This operation is relatively cumbersome and the placement position needs to be adjusted for each centrifugation, affecting the detection efficiency. Summary of the Invention

[0005] In order to solve the problem of geometric asymmetry of the long strip card holder structure in the prior art, which leads to mass moment differences, further causing differences in centrifugal force on the test cards at different positions, and ultimately leading to comparative reading errors in the test results, the present invention aims to provide a special card holder for microcolumn gel immunoassay cards.

[0006] To solve the above problems, the present invention adopts the following technical solutions.

[0007] A special card tray for microcolumn gel immunoassay cards, comprising a first card tray and a second card tray detachably connected to the first card tray, wherein the first card tray and the second card tray are components with the same structure; The first card holder includes a lower connecting member and an upper connecting member fixed to the upper end of the lower connecting member, and the first card holder is detachably connected to the lower connecting member of the second card holder through the upper connecting member; The first card holder also includes support strips that are evenly fixed to the outer surface of the lower connecting piece in a ring shape, one end of each support strip is fixed to a centrifuge cylinder, and the outer surfaces of the centrifuge cylinders distributed in a ring shape are commonly fixed to a fixing ring, and a test card slot is provided on each centrifuge cylinder, and a microcolumn gel test card is inserted into the centrifuge cylinder through the test card slot.

[0008] Furthermore, the microcolumn gel test card includes a test card base inserted into the test card slot, the test card base is evenly provided with connection grooves, the connection grooves are fixedly connected with microcolumn tubes, and the microcolumn tubes are distributed correspondingly to the centrifuge cylinders.

[0009] Furthermore, the number of the centrifugal cylinders is set to an even number and is symmetrically distributed with respect to the fixed ring into two groups of detection positions, and a detection card slot is provided on one side of the centrifugal cylinders at both ends of a single group of detection positions.

[0010] Furthermore, the upper end of the inner wall of the centrifugal cylinder is fixedly connected with an annular multi-chamber silicone body, and fits with the annular multi-chamber silicone body when the micro-column tube is inserted.

[0011] Furthermore, the detection card base is made of a polyurethane elastomer component.

[0012] Furthermore, a centrifugal limiting assembly is provided inside the centrifugal cylinder; The centrifugal limiting assembly includes a through hole opened in the middle position of the bottom of the centrifugal cylinder, an annular airbag is fixedly provided around the bottom wall of the centrifugal cylinder around the through hole, a truncated cone extrusion body is placed on the upper surface of the annular airbag, the lower end of the truncated cone extrusion body is fixedly connected to a connecting rope, and the lower end of the connecting rope extends to the outside of the centrifugal cylinder through the through hole and is fixedly connected to the centrifugal ball, and two groups of trigger assemblies are symmetrically fixedly connected to the two sides of the outer circular surface of the truncated cone extrusion body.

[0013] Furthermore, the trigger assembly includes a pull rod fixedly connected to the outer circular surface of the cone extrusion body, the upper end of the pull rod is fixedly connected to the first wedge block, the side wall of the centrifugal cylinder is fixedly connected to the fixed block, and the pull rod is arranged through the fixed block, a slide groove is provided inside the fixed block, and one end of the slide groove is fixedly connected to a spring, one end of the spring is fixedly connected to a slider, the upper end of the slider is fixedly connected to the second wedge block, and one end of the second wedge block is fixedly connected to the contact plate.

[0014] Furthermore, in a normal state, the diameter of the annular airbag is half of the diameter of the bottom of the centrifugal cylinder, and the annular airbag is elastic.

[0015] Furthermore, the distance between the contact plate and the detection card base is set to 1-2 cm in a static state.

[0016] Furthermore, the cross-sections of the first wedge-shaped block and the second wedge-shaped block are both set to be triangular. When the annular airbag is in a normal state, the inclined surfaces of the first wedge-shaped block and the second wedge-shaped block fit together.

[0017] Compared with the prior art, the present invention has the following beneficial effects: (1) The present application connects multiple card holders through lower connecting parts and upper connecting parts, so that the number of card holders can be expanded or reduced as needed. Secondly, by using support bars and fixed rings, an even number of centrifuge cylinders are evenly distributed in a ring shape, which can ensure that each centrifuge cylinder is at the same distance from the rotating axis, thereby ensuring the same mass moment, and ultimately making the centrifugal force the same, ensuring the accuracy of the test results, and easy to operate, thereby improving the test efficiency; finally, the card holder of the present application can be directly connected to the output shaft of the centrifuge using the connecting parts, and there is no need to move the microcolumn gel test card back to the rotating card holder of the centrifuge, which is convenient to use.

[0018] (2) The present application sets a centrifugal limit assembly to achieve dynamic fixation of the microcolumn gel test card during the centrifugation process, thereby preventing collision between the microcolumn tube and the inner wall of the centrifuge cylinder. In combination with the annular multi-chamber silicone body, the microcolumn gel test card is limited, thereby avoiding deformation and leakage of the microcolumn gel column. Moreover, since the centrifugal force brought by the centrifuge is used for dynamic limitation, no additional mechanical fixing device is required, and no manual operation is required, thereby improving the fixation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the combined structure of the first card tray and the second card tray of the present invention; Figure 2 This is a schematic diagram of the first card holder structure of the present invention; Figure 3 This is a schematic diagram of the structure of the first card tray of the present invention after removing the micro-column gel test card; Figure 4 Schematic diagram of the structure of the micro-column gel detection card of the present invention; Figure 5 For the present invention Figure 2 Schematic diagram of the structure viewed from above; Figure 6 For the present invention Figure 2 A schematic diagram of a front cross-sectional structure; Figure 7 For the present invention Figure 6 Schematic diagram of the enlarged structure at point A in the middle.

[0020] Description of the numbers in the figure: 1. First Cardo; 11. Lower connecting piece; 12. Upper connecting piece; 13. Support bar; 14. Centrifuge cylinder; 15. Test card slot; 16. Fixing ring; 17. Ring-shaped multi-chambered silicone body; 2. Second card holder; 3. Microcolumn gel test card; 31. Test card base; 32. Microcolumn tube; 33. Connection slot; 4. Centrifugal limit assembly; 41. Centrifugal ball; 42. Connecting rope; 43. Annular airbag; 44. Cone extrusion body; 45. Pull rod; 46. Fixed block; 47. First wedge block; 48. Contact plate; 49. Spring; 410. Slider; 411. Second wedge block. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention; it is obvious that the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0022] See also Figures 1 to 7 A microcolumn gel immunoassay card holder includes a first card holder 1 and a second card holder 2 detachably connected to the first card holder 1, wherein the first card holder 1 and the second card holder 2 are components with the same structure; The first card tray 1 includes a lower connecting member 11 and an upper connecting member 12 fixed to the upper end of the lower connecting member 11, and the first card tray 1 is detachably connected to the lower connecting member 11 of the second card tray 2 through the upper connecting member 12; The first card holder 1 also includes support bars 13 that are uniformly fixed to the outer surface of the lower connecting member 11 in a ring shape. One end of the support bars 13 is fixed to the centrifuge cylinder 14, and the outer surfaces of the centrifuge cylinders 14 distributed in a ring shape are commonly fixed with a fixing ring 16. The centrifuge cylinders 14 are each provided with a test card slot 15, and the centrifuge cylinders 14 are inserted with a microcolumn gel test card 3 through the test card slot 15.

[0023] The microcolumn gel test card 3 includes a test card base 31 inserted into the test card slot 15 . The test card base 31 is evenly provided with connection grooves 33 . Microcolumn tubes 32 are fixedly connected in the connection grooves 33 . The microcolumn tubes 32 are distributed correspondingly to the centrifuge cylinders 14 .

[0024] The number of the centrifugal cylinders 14 is set to an even number and is symmetrically distributed with respect to the fixing ring 16 to form two groups of detection positions. The centrifugal cylinders 14 at the first and last ends of a single group of detection positions are provided with detection card slots 15 on one side.

[0025] The upper end of the inner wall of the centrifuge cylinder 14 is fixedly connected to an annular multi-chambered silicone body 17, and when the micro-column tube 32 is inserted, it fits with the annular multi-chambered silicone body 17 to absorb the shaking of the micro-column tube 32 during centrifugation and prevent the micro-column tube 32 from colliding with the side wall of the centrifuge cylinder 14 due to shaking.

[0026] The detection card base 31 is made of a polyurethane elastomer component.

[0027] In view of the problem existing in the existing technology: the geometric asymmetry problem of the long card holder structure will lead to differences in mass moments, which will further lead to differences in the centrifugal forces of the test cards at different positions, and ultimately lead to comparison errors in the test results. To solve this problem, it is also necessary to place the test cards symmetrically in partitions during centrifugation to ensure the balance of mass moments. This operation is relatively cumbersome and the placement position needs to be adjusted for each centrifugation, which affects the detection efficiency.

[0028] During the specific operation, first, the microcolumn gel test card 3 that needs to be centrifuged (the gel filling and sample addition have been completed) is inserted into the centrifuge tube 14 through the test card slot 15, so that the microcolumn tube 32 is in the middle position of the centrifuge tube 14, completing the loading of a single tray before centrifugation; then, the multiple trays can be connected through the lower connecting member 11 and the upper connecting member 12. It should be noted that the selection of the connecting member should ensure that the first tray 1 and the second tray 2 keep rotating synchronously. The illustrated case of this application can be selected, so that the number of trays can be expanded or reduced as needed. Secondly, by using the support bar 13 and the fixing ring 16, an even number of centrifuge tubes 14 are evenly distributed in a ring shape, which can ensure that each centrifuge tube 14 is at the same distance from the rotation axis, thereby ensuring the same mass moment, and finally making the centrifugal force the same, ensuring the accuracy of the test results, and easy operation, thereby improving the test efficiency.

[0029] See also Figures 6 and 7 , a centrifugal limiting component 4 is also provided inside the centrifugal cylinder 14; The centrifugal limiting assembly 4 includes a through hole opened in the middle position of the bottom of the centrifugal cylinder 14, and an annular airbag 43 is fixedly provided on the bottom wall of the centrifugal cylinder 14 around the through hole. A frustum extrusion body 44 is placed on the upper surface of the annular airbag 43, and the lower end of the frustum extrusion body 44 is fixedly connected to the connecting rope 42, and the lower end of the connecting rope 42 extends through the through hole to the outside of the centrifugal cylinder 14 and is fixedly connected to the centrifugal ball 41. Two sets of trigger assemblies are symmetrically fixedly connected to the two sides of the outer circumference of the frustum extrusion body 44.

[0030] The trigger assembly includes a pull rod 45 fixedly connected to the outer cylindrical surface of the cone extrusion body 44, the upper end of the pull rod 45 is fixedly connected to the first wedge block 47, the side wall of the centrifugal cylinder 14 is fixedly connected to the fixed block 46, and the pull rod 45 is arranged through the fixed block 46, a slide groove is provided inside the fixed block 46, and one end of the slide groove is fixedly connected to a spring 49, one end of the spring 49 is fixedly connected to a slider 410, the upper end of the slider 410 is fixedly connected to the second wedge block 411, and one end of the second wedge block 411 is fixedly connected to the contact plate 48.

[0031] In a normal state, the diameter of the annular airbag 43 is half of the bottom diameter of the centrifugal cylinder 14 , and the annular airbag 43 is elastic.

[0032] The distance between the abutment plate 48 and the detection card base 31 is 1-2 cm when in a static state.

[0033] The cross-sections of the first wedge block 47 and the second wedge block 411 are both triangular. When the annular airbag 43 is in a normal state, the inclined surfaces of the first wedge block 47 and the second wedge block 411 fit in contact with each other.

[0034] During centrifugation, the microcolumn gel test card 3 may experience problems such as column displacement, gel column deformation, or leakage due to a certain gap between the microcolumn tube 32 and the inner wall of the centrifuge cylinder 14. The specific analysis is as follows: 1. Displacement Root: The assembly gap (usually >0.5mm) between the microcolumn tube 32 and the inner wall of the centrifuge cylinder 14 causes high-frequency collision under the action of centrifugal force (up to 1000g), resulting in a cumulative displacement of 1-3mm. 2. Deformation mechanism: The displacement causes the gel column to tilt and generates shear stress, which exceeds the strength limit of the polymer chain of the dextran gel (critical shear force is about 0.5N), causing irreversible fracture; 3. Leakage path: The edge of the aluminum foil seal is pulled obliquely, causing the seal to fail. At the same time, the gel cracks form capillary channels, which cause sample leakage under the drive of centrifugal pressure.

[0035] To address the above issues, the present application provides a centrifugal limit assembly 4. During operation, the microcolumn gel test card 3 is placed in the card holder, and the microcolumn tube 32 enters the interior of the centrifuge cylinder 14. At this time, the frustum extrusion body 44 bears the weight of the microcolumn gel test card 3 and provides support. It should be noted here that due to the light weight of the microcolumn gel test card 3, the annular airbag 43 undergoes slight deformation (negligible). During centrifugation, the connected card holder assembly is placed in the centrifuge, and the lower connector 11 of the bottom card holder is fixedly connected to the output shaft of the centrifuge motor (the output shaft of the centrifuge is fixedly connected to the upper connector 12); The centrifugal cylinder 14 drives the centrifugal limit assembly 4 to rotate as a whole. Before the centrifugal motor reaches the rated speed, the centrifugal force on the centrifugal ball 41 gradually increases due to the continuous increase in speed. The centrifugal ball 41 is acted upon by the centrifugal force and gradually increases the pulling force on the truncated cone extrusion body 44 through the connecting rope 42, causing the annular airbag 43 to be compressed and accumulate elastic potential energy. The truncated cone extrusion body 44 gradually descends. During the descent of the truncated cone extrusion body 44, the pull rod 45 and the first wedge block 47 are driven to descend. The descent of the first wedge block 47 generates a force on the inclined surface of the second wedge block 411, causing the second wedge block 411 to move toward the axial center position of the centrifugal cylinder 14. The movement of the second wedge block 411 drives the movement of the slider 410 and the contact plate 48, causing the spring 49 to be stretched and accumulate elastic potential energy. After the centrifugal motor reaches the rated speed, the centrifugal force remains unchanged and is at its maximum. At this time, the cone extrusion body 44 drops to the lowest position, and the contact plate 48 presses against the detection card base 31, thereby dynamically fixing the microcolumn gel detection card 3 during the centrifugation process. After the centrifugation is completed, the centrifugal motor stops rotating. Under the elastic potential energy of the spring 49 and the annular airbag 43, the centrifugal limit assembly 4 is reset, and the microcolumn gel detection card 3 is no longer fixed.

[0036] By providing the centrifugal limiting assembly 4, the microcolumn gel test card 3 can be dynamically fixed during the centrifugation process, thereby preventing collision between the microcolumn tube 32 and the inner wall of the centrifuge cylinder 14. In combination with the annular multi-chambered silicone body 17, the microcolumn gel test card 3 is limited, thereby avoiding deformation and leakage of the gel column in the microcolumn tube 32. Moreover, since the centrifugal force generated by the centrifuge is used for dynamic limiting, no additional mechanical fixing device is required, and no manual operation is required, thereby improving the fixing efficiency.

[0037] Instructions for use: When using the present invention, first, insert the microcolumn gel test card 3 to be centrifuged into the centrifuge cylinder 14 using the test card slot 15, so that the microcolumn tube 32 is in the middle position of the centrifuge cylinder 14, completing the loading of a single card tray before centrifugation; then, multiple card trays can be connected using the lower connecting member 11 and the upper connecting member 12. It should be noted that the selection of the connecting member should ensure that the first card tray 1 and the second card tray 2 maintain synchronous rotation. The example shown in the figure of this application can be selected, so that the number of card trays can be expanded or reduced as needed; Then, the microcolumn gel test card 3 is placed in the card holder, and the microcolumn tube 32 enters the interior of the centrifuge cylinder 14. At this time, the cone extrusion body 44 bears the weight of the microcolumn gel test card 3 and provides support. During centrifugation, the centrifuge cylinder 14 drives the centrifugal limit assembly 4 to rotate as a whole. Before the centrifugal motor reaches the rated speed, the centrifugal force on the centrifugal ball 41 gradually increases due to the continuous increase in speed. The centrifugal ball 41 is subjected to the centrifugal force and gradually increases the pressure on the cone extrusion body 44 through the connecting rope 42. The pulling force causes the annular airbag 43 to be compressed and accumulate elastic potential energy, and the truncated cone extrusion body 44 gradually descends. During the descent of the truncated cone extrusion body 44, the pull rod 45 and the first wedge block 47 are driven to descend. The descent of the first wedge block 47 generates a force on the inclined surface of the second wedge block 411, causing the second wedge block 411 to move toward the axis of the centrifugal cylinder 14. The movement of the second wedge block 411 drives the movement of the slider 410 and the contact plate 48, causing the spring 49 to be stretched and accumulate elastic potential energy. After the centrifugal motor reaches the rated speed, the centrifugal force remains constant and at its maximum. At this time, the cone extrusion body 44 drops to the lowest position, and the abutment plate 48 presses against the test card base 31, thus dynamically fixing the microcolumn gel test card 3 during the centrifugation process. After the centrifugation is completed, the centrifugal motor stops rotating, and the centrifugal limit assembly 4 is reset under the elastic potential energy of the spring 49 and the annular airbag 43, and the microcolumn gel test card 3 is no longer fixed. After the centrifugation is completed, the microcolumn gel detection card 3 is taken out and a positive control is performed to obtain the detection result of the sample and complete the detection.

[0038] The above description is merely a preferred embodiment of the present invention; however, the scope of protection of the present invention is not limited thereto. Any person skilled in the art who, within the technical scope disclosed by the present invention, makes equivalent substitutions or modifications based on the technical solutions and improved concepts of the present invention shall be covered by the scope of protection of the present invention.

Claims

1. A dedicated card holder for a microcolumn gel immunoassay card, comprising a first card holder (1) and a second card holder (2) detachably connected to the first card holder (1), wherein the first card holder (1) and the second card holder (2) are components with the same structure; Its characteristics are: The first card holder (1) comprises a lower connecting member (11) and an upper connecting member (12) fixedly connected to the upper end of the lower connecting member (11), and the first card holder (1) is detachably connected to the lower connecting member (11) of the second card holder (2) via the upper connecting member (12); The first card holder (1) further comprises a support bar (13) uniformly fixed to the outer surface of the lower connecting member (11) in an annular shape, one end of each support bar (13) being fixed to a centrifuge cylinder (14), and a fixing ring (16) being fixed to the outer surface of the annularly distributed centrifuge cylinders (14), each of which is provided with a test card slot (15), and a microcolumn gel test card (3) is inserted into the centrifuge cylinder (14) through the test card slot (15).

2. The dedicated card holder for microcolumn gel immunoassay card according to claim 1, characterized in that: The microcolumn gel detection card (3) comprises a detection card base (31) inserted into the detection card slot (15), the detection card base (31) is evenly provided with connection grooves (33), the connection grooves (33) are fixedly connected with microcolumn tubes (32), and the microcolumn tubes (32) are distributed correspondingly to the centrifuge cylinder (14).

3. The dedicated card holder for microcolumn gel immunoassay card according to claim 2, characterized in that: The number of the centrifugal cylinders (14) is set to an even number and is symmetrically distributed with respect to the fixed ring (16) into two groups of detection positions. The centrifugal cylinders (14) at the first and last ends of a single group of detection positions are provided with detection card slots (15) on one side.

4. The dedicated card holder for microcolumn gel immunoassay card according to claim 2, characterized in that: The upper end of the inner wall of the centrifugal cylinder (14) is fixedly connected to an annular multi-chambered silica gel body (17), and fits with the annular multi-chambered silica gel body (17) when the micro-column tube (32) is inserted.

5. The dedicated card holder for microcolumn gel immunoassay card according to claim 4, characterized in that: The detection card base (31) is made of a polyurethane elastomer component.

6. The dedicated card holder for microcolumn gel immunoassay card according to claim 1, characterized in that: A centrifugal limiting assembly (4) is further provided inside the centrifugal cylinder (14); The centrifugal limiting assembly (4) comprises a through hole opened in the middle position of the bottom of the centrifugal cylinder (14), an annular airbag (43) is fixedly provided on the bottom wall of the centrifugal cylinder (14) around the through hole, a truncated cone extrusion body (44) is placed on the upper surface of the annular airbag (43), the lower end of the truncated cone extrusion body (44) is fixedly connected to a connecting rope (42), and the lower end of the connecting rope (42) extends through the through hole to the outside of the centrifugal cylinder (14) and is fixedly connected to the centrifugal ball (41), and two sets of trigger assemblies are symmetrically fixedly connected to the outer circumference of the truncated cone extrusion body (44).

7. The dedicated card holder for microcolumn gel immunoassay card according to claim 6, characterized in that: The trigger assembly includes a pull rod (45) fixedly connected to the outer cylindrical surface of the truncated cone extrusion body (44), the upper end of the pull rod (45) is fixedly connected to the first wedge block (47), the side wall of the centrifugal cylinder (14) is fixedly connected to the fixed block (46), and the pull rod (45) passes through the fixed block (46), a sliding groove is provided inside the fixed block (46), and one end of the sliding groove is fixedly connected to a spring (49), one end of the spring (49) is fixedly connected to a slider (410), the upper end of the slider (410) is fixedly connected to the second wedge block (411), and one end of the second wedge block (411) is fixedly connected to the contact plate (48).

8. The dedicated card holder for microcolumn gel immunoassay card according to claim 7, characterized in that: In a normal state, the diameter of the annular airbag (43) is half the diameter of the bottom of the centrifugal cylinder (14), and the annular airbag (43) is elastic.

9. The dedicated card holder for microcolumn gel immunoassay card according to claim 7, characterized in that: The distance between the contact plate (48) and the detection card base (31) is set to 1-2 cm in a static state.

10. The dedicated card holder for microcolumn gel immunoassay card according to claim 7, characterized in that: The cross-sections of the first wedge-shaped block (47) and the second wedge-shaped block (411) are both triangular, and when the annular airbag (43) is in a normal state, the inclined surfaces of the first wedge-shaped block (47) and the second wedge-shaped block (411) fit into each other.

Images