Adapter assembly with anti-lifting structure

Abstract

The utility model discloses an adapter assembly with prevent belt to rise structure, including an adapter body and at least two prevent belt to rise assembly, prevent belt to rise assembly part is connected or is formed in a table top, and the table top forms a support surface, the adapter body is placed on the support surface and is detachably connected the table top through prevent belt to rise assembly, the utility model discloses an adapter assembly with prevent belt to rise structure has solved the problem that the adapter body is easy to take up simultaneously when ascending consumables.

Description

Technical Field

[0001] This utility model belongs to the technical field of reagent testing equipment, and in particular relates to an adapter assembly with an anti-slip structure. Background Technology

[0002] Most existing adapters do not have a connection structure with the upper consumables, and the upper consumables are placed directly on the adapter, which is prone to displacement during use. For adapters with a connection structure with the upper consumables, when external equipment or personnel need to raise the consumables, the consumables are prone to pulling up the lower connected adapter at the same time, which can affect reagent testing and easily damage the equipment. Summary of the Invention

[0003] To address the shortcomings of the existing technology, this utility model aims to provide an adapter assembly with an anti-lifting structure, which solves the problem that the adapter body is easily lifted when the consumable is being raised.

[0004] To achieve the above objectives, this utility model provides an adapter assembly with an anti-slip structure, including an adapter body and at least two anti-slip components; the anti-slip components are partially connected to or formed on a table, and the table forms a support surface; the adapter body is placed on the support surface and is detachably connected to the table through the anti-slip components.

[0005] In one embodiment, each anti-tipping assembly includes a first buckle and a second buckle; the first buckle is pivotally connected to both sides of the adapter body at its center; at least one first hook is formed on the inner bottom side of the first buckle; the second buckle is connected to or formed on the platform and is positioned corresponding to the first buckle; at least one second hook is formed on the outer upper part of the second buckle to engage with the first hook; at least one braking assembly is provided between the first buckle and the adapter body; the braking assembly provides a force for the first hook of the first buckle to rotate toward the adapter body; when the anti-tipping assembly is in a locked state, the first hook abuts against the second buckle and engages with the second hook, and the adapter body is connected through the first hook and the second hook; when the upper part of the first buckle is subjected to force and adheres to the adapter body and is located in an unlocked position, the first hook and the second hook are unlocked.

[0006] In one embodiment, a snap-fit ​​mounting groove is formed on each of the two sides of the adapter body. The first snap-fit ​​is pivotally connected to the snap-fit ​​mounting groove via a pivot. A limiting part is formed on the inner wall of the snap-fit ​​mounting groove. The limiting part limits the upper part of the first snap-fit. When the inner side of the upper part of the first snap-fit ​​is in contact with the limiting part, the first snap-fit ​​is in the unlocked position.

[0007] In one embodiment, a convex edge is formed on the top outer side of the first buckle along its length.

[0008] In one embodiment, the braking assembly includes a spring that is press-fitted between the upper part of the first buckle and the adapter body.

[0009] In one embodiment, the braking assembly includes a torsion spring; the inner wall of the first buckle is provided with a plurality of torsion spring mounting slots, the torsion spring is disposed in the torsion spring mounting slots and sleeved on the outside of the rotating shaft, and the first end of the torsion spring is connected to the adapter body, and the second end of the torsion spring abuts against the upper inner side of the torsion spring mounting slot.

[0010] In one embodiment, the braking assembly includes a first spring plate, which is arc-shaped and horizontally pressed between the upper part of the adapter body and the first buckle, with only one end of the first spring plate connected to the adapter body.

[0011] In one embodiment, the adapter body forms a spring limiting structure at the position corresponding to the first spring; the first end of the first spring is connected to the adapter body by a first bolt, and the spring limiting structure limits the first spring so that the second end of the first spring can only slide back and forth in the horizontal direction, and the first buckle is recessed at the position corresponding to the first bolt to form an avoidance structure.

[0012] In one embodiment, the braking assembly includes a magnetic assembly, each of which includes a first magnet and a second magnet. The first magnet is mounted on the inner side of the upper part of the first buckle, and the second magnet is mounted on the outer side of the adapter body and is positioned corresponding to the first magnet. The first magnet and the second magnet are arranged in a corresponding manner.

[0013] In one implementation, the adapter body is further provided with connection structures at both ends.

[0014] In one embodiment, the connection structure includes two second spring contacts, which are oppositely connected to the outer sides of both ends of the adapter body; the second spring contacts are bent inward and downward from the top and form a protrusion on the upper inner side.

[0015] The beneficial technical effects of this utility model due to the adoption of the above technical solution include:

[0016] The anti-lift component enables a detachable connection between the adapter body and the platform, effectively preventing the adapter body from being lifted when consumables mounted on top of it rise. The cooperation of the first and second latches and the braking component allows for easy latching of the first and second latches without external force, and easy unlocking by applying external force to the upper part of the first latch. The latch mounting slot accommodates the first latch. The limiting part secures the upper part of the first latch, ensuring it remains stably in the unlocked position under external force. The protruding edge allows the mechanical gripper to exert an upward force on the protruding edge when unlocking is applied, reducing the lateral force required for unlocking and ensuring its effectiveness. The connecting structure connects the consumables placed above the adapter body, preventing displacement during use. The connecting structure uses a second spring, facilitating easy vertical insertion and separation of the consumables and the adapter body. The support surface is used to support the adapter body and ensure the relative position of the first and second latches in the vertical direction. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments 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.

[0018] Figure 1 This is a perspective view of the adapter assembly with an anti-slip structure in Embodiment 1 of this application;

[0019] Figure 2 This is a perspective view of the adapter body in Embodiment 1 of this application;

[0020] Figure 3 This is a perspective view of the base in Embodiment 1 of this application;

[0021] Figure 4 This is a perspective view of the first buckle in Embodiment 1 of this application;

[0022] Figure 5 This is a perspective view of the second buckle in Embodiment 1 of this application;

[0023] Figure 6 This is a structural schematic diagram of the snap-fit ​​state of the first and second snaps in Embodiment 1 of this application;

[0024] Figure 7 This is a schematic diagram showing the unlocked state of the first and second latches in Embodiment 1 of this application;

[0025] Figure 8 This is a usage diagram of the adapter assembly with an anti-slip structure in Embodiment 1 of this application;

[0026] Figure 9 This is a schematic diagram of the connection structure of the torsion spring in Embodiment 2 of this application;

[0027] Figure 10 This is a schematic diagram of the connection structure between the torsion spring and the first buckle in Embodiment 2 of this application;

[0028] Figure 11 This is a side view of the connection structure of the first spring in Embodiment 3 of this application;

[0029] Figure 12 This is a bottom view of the connection structure of the first spring in Embodiment 3 of this application;

[0030] Figure 13 This is a perspective view of the first spring clip in Embodiment 3 of this application;

[0031] Figure 14 This is a perspective view of the first buckle in Embodiment 3 of this application;

[0032] Figure 15 This is a side view of the connection structure of the second magnet in Embodiment 4 of this application;

[0033] Figure 16 This is a schematic diagram of the connection structure between the first magnet and the first buckle in Embodiment 4 of this application;

[0034] Figure 17 This is a schematic diagram of the connection structure between the first magnet and the second magnet in Embodiment 4 of this application.

[0035] Explanation of icon numbers:

[0036] 1-Adapter body;

[0037] 101-Snap-on mounting slot; 102-V-shaped countersunk hole;

[0038] 111-Limiting part;

[0039] 2-Base;

[0040] 21-Top surface of base; 22-Positioning buckle; 23-Bottom surface of base; 24-Accommodation space; 25-Ring;

[0041] 221 - Support bottom surface; 222 - Side surface;

[0042] 3-First buckle;

[0043] 31-First hook; 32-Torsion spring mounting slot; 33-Avoidance structure; 34-Protruding edge;

[0044] 4-Second buckle;

[0045] 41-Second hook; 42-Positioning pin hole;

[0046] 5-Spindle;

[0047] 6-Spring;

[0048] 7- Torsion spring;

[0049] 8-First shrapnel;

[0050] 91 - First magnet; 92 - Second magnet;

[0051] 10 - Second fragment;

[0052] 11-Consumables. Detailed Implementation

[0053] 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, and 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 protection scope of the present utility model.

[0054] In the description of this utility model, it should be noted that the terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing 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. Furthermore, the terms "first," "second," and "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0055] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "setting," "connection," "linking," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or a connection within 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.

[0056] Example 1

[0057] Please see Figures 1 to 8An adapter assembly with an anti-slip structure according to Embodiment 1 of this utility model includes an adapter body 1 and at least two anti-slip components; the anti-slip components are partially connected to or formed on a table; the table forms a support surface; the adapter body 1 is placed on the support surface and is detachably connected to the table through the anti-slip components.

[0058] Each anti-slip assembly includes a first buckle 3 and a second buckle 4; the first buckle 3 is pivotally connected to both sides of the adapter body 1 at its center; at least one first hook 31 is formed on the inner bottom side of the first buckle 3; the second buckle 4 is connected to or formed on the table surface and is positioned corresponding to the first buckle 3; at least one second hook 41 is formed on the outer upper part of the second buckle 4 to cooperate with the first hook 31; at least one braking assembly is provided between the first buckle 3 and the adapter body 1; the braking assembly provides a force for the first hook 31 of the first buckle 3 to rotate toward the adapter body 1; when the anti-slip assembly is in a locked state, the first hook 31 abuts against the second buckle 4 and engages with the second hook 41, and the adapter body 1 is connected by the first hook 31 and the second hook 41; when the upper part of the first buckle 3 is subjected to force and adheres to the adapter body 1 and is located in an unlocked position, the first hook 31 and the second hook 41 are unlocked.

[0059] In this embodiment, the second buckle 4 is fixed to the upper surfaces of both sides of the tabletop by the second bolt. Simultaneously, the second buckle 4 is provided with positioning pin holes 42, and the base 2 is provided with positioning pins. When installing the second buckle 4, the positioning pins are inserted into the positioning pin holes 42 to quickly position the second buckle 4, and then the second bolts are tightened to fix the second buckle 4. In other embodiments, the second buckle 4 can also be formed directly on both sides of the tabletop, or the connection between the second buckle 4 and the tabletop can be achieved through adhesive or other existing means. In other embodiments, the structure of positioning pin holes 42 and positioning pins may not be provided. The upper end face of the adapter body 1 is arrayed with 96 V-shaped countersunk holes 102 for the adapter consumables 11. In other embodiments, the upper end face of the adapter body 1 can form other corresponding numbers of countersunk holes to match the corresponding consumables 11.

[0060] The anti-lift component enables a detachable connection between the adapter body 1 and the tabletop, effectively preventing the adapter body 1 from being lifted simultaneously when the consumable 11 installed above it rises. The cooperation of the first latch 3, the second latch 4, and the elastic element allows for easy latching of the first latch 3 and the second latch 4 without external force, and easy unlocking of the first latch 3 and the second latch 4 by applying external force to the upper part of the first latch 3. The support surface supports the adapter body 1, ensuring the relative position of the first latch 3 and the second latch 4 in the vertical direction.

[0061] The adapter body 1 has a buckle mounting groove 101 recessed on both sides. The first buckle 3 is pivotally connected to the buckle mounting groove 101 via a pivot 5. A limiting part 111 is formed on the inner wall of the buckle mounting groove 101. The limiting part 111 limits the upper part of the first buckle 3. When the inner side of the upper part of the first buckle 3 is in contact with the limiting part 111, the first buckle 3 is in the unlocked position.

[0062] The latch mounting slot 101 is used to install and accommodate the first latch 3. The limiting part 111 is used to limit the upper part of the first latch 3, so that the first latch 3 can be stably stopped in the unlocked position when an external force is applied.

[0063] In this embodiment, both ends of the snap-fit ​​mounting groove 101 are also formed with shaft mounting grooves. The two ends of the shaft 5 are respectively inserted into the corresponding shaft mounting grooves. The snap-fit ​​mounting groove 101 and the shaft mounting groove have openings at the bottom to facilitate the installation of the first snap-fit ​​3 and the shaft 5. A limiting screw, screwed to the adapter body 1, passes through the bottom of the shaft 5 to limit its position. In other embodiments, the shaft 5 can also be limited by other structures, such as a closed structure below the shaft mounting groove.

[0064] In this embodiment, the braking component uses a spring 6, which is pressed and connected between the upper part of the first buckle 3 and the adapter body 1; in other embodiments, the elastic element may also use other existing elastic structures and components.

[0065] Example 2

[0066] Please see Figures 9-10 The adapter assembly with an anti-lifting structure in Embodiment 2 of this utility model has a structure that is basically the same as that in Embodiment 1. The difference is that the braking assembly adopts a torsion spring 7; the inner wall of the first buckle 3 is provided with a plurality of torsion spring mounting grooves 32, the torsion spring 7 is disposed in the torsion spring mounting groove 32 and sleeved on the outside of the rotating shaft 5, and the first end of the torsion spring 7 is connected to the adapter body 1, and the second end of the torsion spring 7 abuts against the upper inner side of the torsion spring mounting groove 32.

[0067] In this embodiment, a torsion spring mounting hole is formed on the lower inner wall of the snap-fit ​​mounting groove 101, and the first end of the torsion spring 7 is inserted and fixed in the torsion spring mounting hole. In other embodiments, other existing fixing methods can also be used for the end of the torsion spring 7.

[0068] Example 3

[0069] Please see Figures 11-14The adapter assembly with an anti-lifting structure in Embodiment 3 of this utility model has a structure that is basically the same as that in Embodiment 1. The difference is that the braking assembly adopts a first spring plate 8. The first spring plate 8 is arc-shaped and horizontally pressed between the adapter body 1 and the upper part of the first buckle 3. Only one end of the first spring plate 8 is connected to the adapter body 1.

[0070] The adapter body 1 forms a spring-loaded limiting structure at the position corresponding to the first spring-loaded piece 8; the first end of the first spring-loaded piece 8 is connected to the adapter body 1 by a first bolt, and the spring-loaded limiting structure limits the first spring-loaded piece 8 so that the second end of the first spring-loaded piece 8 can only slide back and forth in the horizontal direction. The first buckle 3 is recessed at the position corresponding to the first bolt to form an avoidance structure 33. The use of the avoidance structure 33 makes the structure between the upper part of the first buckle 3 and the adapter body 1 more compact.

[0071] In this embodiment, the spring sheet limiting structure adopts a groove. In other embodiments, the spring sheet limiting structure may also adopt existing limiting structures such as a sliding groove.

[0072] Example 4

[0073] Please see Figures 15-17 The adapter assembly with an anti-lifting structure in Embodiment 4 of this utility model has a structure that is basically the same as that in Embodiment 1. The difference is that the braking component is a magnetic component. At least one magnetic component is provided between the first buckle 3 and the adapter body 1. The magnetic component provides a force for the first hook 31 of the first buckle 3 to rotate in the direction of the adapter body 1. The cooperation of the first buckle 3, the second buckle 4 and the magnetic component can easily realize the buckling connection between the first buckle 3 and the second buckle 4 when no external force is applied. And the first buckle 3 and the second buckle 4 can be easily unlocked by applying an external force to the upper part of the first buckle 3.

[0074] Each of the magnetic components includes a first magnet 91 and a second magnet 92. The first magnet 91 is installed on the upper inner side of the first buckle 3, and the second magnet 92 is installed on the outer side of the adapter body 1 and its position corresponds to that of the first magnet 91. The first magnet 91 and the second magnet 92 are arranged in a corresponding manner.

[0075] In this embodiment, the first magnet 91 and the second magnet 92 are glued to the first buckle 3 and the adapter body 1 respectively, using the principle of like poles repelling each other to achieve elasticity, thus achieving the same effect as the spring 6.

[0076] Example 5

[0077] Please see Figures 1 to 17The adapter assembly with an anti-slip structure in Embodiment 5 of this utility model has a structure that is basically the same as any one of Embodiments 1 to 4, except that a protruding edge 34 is formed on the outer side of the top of the first buckle 3 along the length direction.

[0078] The use of the protruding edge 34 allows the mechanical gripper to generate an upward force on the protruding edge 34 when an external force is applied for unlocking via the mechanical gripper, thereby reducing the lateral force required for unlocking and ensuring the effectiveness of unlocking.

[0079] Example 6

[0080] The adapter assembly with an anti-slip structure in Embodiment Six of this utility model has a structure that is basically the same as that in Embodiment Five. The difference is that the two ends of the adapter body 1 are also provided with a connection structure.

[0081] In this embodiment, the connection structure includes two second spring pieces 10, which are connected to the outer sides of both ends of the adapter body 1; the second spring pieces 10 are bent inward and downward from the top and form a protrusion on the upper inner side.

[0082] The connection structure is used to connect the consumable 11 placed above the adapter body 1, preventing the consumable 11 from shifting during use. The connection structure uses a second spring 10, which can easily realize the vertical insertion and separation of the consumable 11 and the adapter body 1.

[0083] Example 7

[0084] The adapter assembly with an anti-slip structure in Embodiment 7 of this utility model has a structure that is basically the same as that in Embodiment 6. The difference is that the anti-slip assembly is partially connected to or formed on the top surface 21 of a base 2; the top surface 21 of the base is connected to or formed with a horizontal limiting structure, which limits the adapter body 1 in the horizontal direction; and the second buckle 4 is connected to or formed on the top surface 21 of the base.

[0085] The horizontal limiting structure includes four positioning buckles 22, each positioning buckle 22 including a supporting bottom surface 221 and two side surfaces 222; the two side surfaces 222 are vertically connected to the supporting bottom surface 221 and are perpendicularly connected to each other; the positioning buckles 22 are respectively fixed to the four corners of the top surface 21 of the base; each supporting bottom surface 221 cooperates to form the supporting surface.

[0086] The adoption of a horizontal limiting structure achieves horizontal limitation of the adapter body 1. The structure of the four positioning buckles 22 can quickly position and limit the four corners of the adapter body 1, thereby achieving horizontal limitation of the adapter body 1.

[0087] Example 8

[0088] The adapter assembly with an anti-slip structure in Embodiment 8 of this utility model is basically the same in structure as that in Embodiment 7, except that the base 2 further includes a base bottom surface 23, and a receiving space 24 is formed between the base top surface 21 and the base bottom surface 23. The receiving space 24 can be used to place PCR consumables for convenient reagent detection operations.

[0089] In this embodiment, the accommodating space 24 is formed between the top surface 21 and the bottom surface 23 of the base by connecting multiple rods 25 at intervals. In other embodiments, the top surface 21 and the bottom surface 23 of the base may also adopt other existing connection structures.

[0090] This embodiment provides an adapter assembly with an anti-lifting structure. The base 2 is fixed to a platform. In use, the first buckle 3 and the second buckle 4 of the adapter body 1 are aligned. The adapter body 1 is placed on the support surface and detachably connected to the base 2 via the anti-lifting structure. Then, the consumable 11 is inserted and fixed to the adapter body 1 via a connecting structure. When the consumable 11 needs to be replaced, it can be pulled upwards directly; the adapter body 1 will not be lifted by the anti-lifting structure. When the adapter body 1 needs to be removed, the first buckle 3 is pressed inwards with external force to rotate it to the unlocked position, unlocking the first buckle 3 and the second buckle 4, at which point the adapter body 1 can be removed.

[0091] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.

Claims

1. An adapter assembly with an anti-slip structure, characterized in that, It includes an adapter body (1) and at least two anti-slip-up components; the anti-slip-up components are partially connected to or formed on a table, the table forming a support surface; the adapter body (1) is placed on the support surface and is detachably connected to the table through the anti-slip-up components.

2. The adapter assembly with an anti-slip structure according to claim 1, characterized in that, Each anti-tipping component includes a first buckle (3) and a second buckle (4); the first buckle (3) is pivotally connected to both sides of the adapter body (1) at its center; at least one first hook (31) is formed on the inner bottom side of the first buckle (3); the second buckle (4) is connected to or formed on the platform and its position corresponds to the first buckle (3); at least one second hook (41) is formed on the outer upper part of the second buckle (4) to cooperate with the first hook (31); at least one braking component is provided between the first buckle (3) and the adapter body (1); The braking assembly provides a force that rotates the first hook (31) of the first buckle (3) toward the adapter body (1); when the anti-slip assembly is in the locked state, the first hook (31) abuts against the second buckle (4) and engages with the second hook (41), and the adapter body (1) is connected by the first hook (31) and the second hook (41); when the upper part of the first buckle (3) is subjected to force and adheres to the adapter body (1) and is located in an unlocked position, the first hook (31) and the second hook (41) are unlocked.

3. The adapter assembly with an anti-slip structure according to claim 2, characterized in that, The adapter body (1) has recesses on both sides to form a buckle mounting groove (101). The first buckle (3) is pivotally connected to the buckle mounting groove (101) via a pivot (5). A limiting part (111) is formed on the inner wall of the buckle mounting groove (101). The limiting part (111) limits the upper part of the first buckle (3). When the inner side of the upper part of the first buckle (3) is in contact with the limiting part (111), the first buckle (3) is in the unlocked position.

4. The adapter assembly with an anti-slip structure according to claim 2, characterized in that, The top outer side of the first buckle (3) forms a protruding edge (34) along the length direction.

5. The adapter assembly with an anti-slip structure according to claim 2, characterized in that, The braking assembly includes a spring (6) which is pressed between the upper part of the first buckle (3) and the adapter body (1).

6. The adapter assembly with an anti-slip structure according to claim 3, characterized in that, The braking assembly includes a torsion spring (7); the inner wall of the first buckle (3) is provided with a plurality of torsion spring mounting grooves (32), the torsion spring (7) is disposed in the torsion spring mounting groove (32) and sleeved on the outside of the rotating shaft (5), and the first end of the torsion spring (7) is connected to the adapter body (1), and the second end of the torsion spring (7) abuts against the upper inner side of the torsion spring mounting groove (32).

7. The adapter assembly with an anti-slip structure according to claim 2, characterized in that, The braking assembly includes a first spring (8), which is arc-shaped and horizontally pressed between the upper part of the adapter body (1) and the first buckle (3). Only one end of the first spring (8) is connected to the adapter body (1).

8. The adapter assembly with an anti-slip structure according to claim 7, characterized in that, The adapter body (1) forms a spring limiting structure at the position corresponding to the first spring (8); the first end of the first spring (8) is connected to the adapter body (1) by the first bolt, and the spring limiting structure limits the first spring (8) so that the second end of the first spring (8) can only slide back and forth in the horizontal direction, and the first buckle (3) is recessed at the position corresponding to the first bolt to form an avoidance structure (33).

9. The adapter assembly with an anti-slip structure according to claim 3, characterized in that, The braking assembly includes a magnetic assembly, each of which includes a first magnet (91) and a second magnet (92). The first magnet (91) is installed on the upper inner side of the first buckle (3), and the second magnet (92) is installed on the outer side of the adapter body (1) and its position corresponds to that of the first magnet (91). The first magnet (91) and the second magnet (92) are arranged in the same order.

10. The adapter assembly with an anti-slip structure according to claim 3, characterized in that, The adapter body (1) is also provided with connection structures at both ends.

11. The adapter assembly with an anti-slip structure according to claim 10, characterized in that, The connection structure includes two second springs (10), which are connected to the outer sides of both ends of the adapter body (1); the second springs (10) are bent inward and downward from the top and form a protrusion on the upper inner side.

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