Triangular well lid elastic lock mechanism

Abstract

The utility model relates to the field of municipal well lids and rainwater grates, and particularly discloses a triangular well lid elastic lock mechanism which comprises an elastic lock, and the elastic lock comprises a lock arm and a lock head. The locking arm comprises a connecting arm, a main elastic arm, a first arc arm, an auxiliary elastic arm, a second arc arm and a fixing arm, one side of the second arc arm is connected with the fixing arm, the side, away from the fixing arm, of the second arc arm is connected with the auxiliary elastic arm, one side of the first arc arm is connected with the auxiliary elastic arm, and the other side of the first arc arm is connected with the fixing arm. The side, away from the auxiliary elastic arm, of the first arc arm is connected with the main elastic arm, and one side of the connecting arm is connected with the main elastic arm. The locking groove is composed of a locking face, a left limiting table and a right limiting table. The elastic lock mechanism aims at solving the technical problem that an existing elastic lock mechanism cannot be effectively applied to a triangular well lid due to the problems of large occupied space, mismatched structure and the like.

Description

Technical Field

[0001] This utility model relates to the field of municipal manhole covers and storm drain grates, specifically a triangular manhole cover elastic locking mechanism. Background Technology

[0002] Manhole covers play a vital role in urban infrastructure systems. As covers for manholes, they bear the crucial mission of protecting manholes and preventing people or objects from accidentally falling in, making them a fundamental component for ensuring urban public safety and normal operation. With the continuous advancement and diversified development of urban construction, the types of manhole covers have become increasingly diverse. In addition to the traditionally common round and rectangular manhole covers, triangular manhole covers are also widely used in specific areas and scenarios due to their unique applicability.

[0003] To ensure the safe and stable operation of manhole covers in various environments, reliable and effective locking devices are essential. Elastic locks, utilizing the elastic deformation and rebound force of metal to achieve a tight connection between the manhole cover and the base, stand out among numerous manhole cover locking methods and have become a widely used choice. Existing technologies, such as the variable cross-section elastic lock structure disclosed in patent "A Manhole Cover Elastic Lock Mechanism (ZL202220192760.7)," have designed corresponding elastic lock arm schemes for manhole covers of different shapes. Specifically, the C-type elastic lock arm is adapted to round covers, with three lock arms evenly distributed around the circumference of each round cover to ensure uniform force distribution and effectively prevent torsion of the round cover during use; the L-type elastic lock arm is suitable for rectangular covers, with two lock arms symmetrically distributed on the rectangular cover, also achieving good force balance and anti-torsion effects. However, both of these lock arms have a significant limitation in practical applications—they require a large amount of space.

[0004] Triangular manhole covers present numerous challenges in arranging locking arms due to their unique triangular geometry. Their relatively limited space cannot accommodate larger locking arms, and their shape makes it difficult to achieve a symmetrical or even distribution of multiple locking arms as with round or rectangular manhole covers. This prevents the direct application of traditional C-type or L-type elastic locking arms to triangular manhole covers, resulting in potential safety and stability issues related to locking.

[0005] Therefore, there is an urgent need for a triangular manhole cover elastic locking mechanism to solve the above problems. Utility Model Content

[0006] In view of this, this utility model proposes an elastic locking mechanism for triangular manhole covers, aiming to solve the technical problem that existing elastic locking mechanisms cannot be effectively applied to triangular manhole covers due to problems such as large space occupation and structural mismatch. This enables the triangular manhole covers to be locked safely, reliably, and efficiently, thereby improving the performance and safety of triangular manhole covers in municipal facilities.

[0007] In one aspect, this utility model provides a triangular manhole cover elastic locking mechanism, comprising:

[0008] The resilient lock is V-shaped and is located on the short side of the triangular manhole cover. The resilient lock includes a locking arm and a locking head.

[0009] The locking arm includes a connecting arm, a main elastic arm, a first arc arm, a secondary elastic arm, a second arc arm, and a fixed arm. The fixed arm is perpendicularly connected to the load-bearing rib of the triangular manhole cover. One side of the second arc arm is engaged with the fixed arm, and the side of the second arc arm away from the fixed arm is engaged with the secondary elastic arm. The secondary elastic arm is parallel to the short side of the triangular manhole cover in the horizontal direction. One side of the first arc arm is engaged with the secondary elastic arm, and the side of the first arc arm away from the secondary elastic arm is engaged with the main elastic arm. One side of the connecting arm is engaged with the main elastic arm, and the side of the connecting arm away from the main elastic arm is engaged with the lock head. The connecting arm is perpendicular to the secondary elastic arm.

[0010] The locking groove is provided on the well base and consists of a locking surface, a left limiting platform, and a right limiting platform.

[0011] Furthermore, the locking arm is a structure with one end suspended, the joint surface between the fixed arm and the load-bearing rib is the root end face of the locking arm, the joint surface between the connecting arm and the lock head is the front end face of the locking arm, the height of the root end face is higher than the height of the front end face, and the thickness of the root end face is greater than the thickness of the front end face.

[0012] Furthermore, both the first and second arc arms are arc-shaped structures, with the arc length of the first arc arm being greater than that of the second arc arm.

[0013] Furthermore, the lock head is composed of an upper inclined surface, a lower inclined surface, and a lock tip arc. The lock head is engaged with the connecting arm of the lock arm, and the width of the lock head is twice the width of the front end face.

[0014] Furthermore, the locking surface is a segmented inclined surface, consisting of an upper locking surface, a main locking surface, and a lower locking surface.

[0015] Furthermore, the width of the locking surface is wider than the width of the lock head, the upper locking surface and the main locking surface are effective working surfaces, and the lower locking surface is a protective plane.

[0016] Furthermore, the left and right limiting platforms are located on both sides of the locking surface to restrict the left and right movement of the lock head and to restrict the deflection of the triangular manhole cover.

[0017] Furthermore, the upper locking surface has an angle of 5° with the vertical direction, the main locking surface has an angle of 20° with the vertical direction, and the lower locking surface has an angle of 50° with the vertical direction.

[0018] Furthermore, the angle between the main elastic arm and the secondary elastic arm is 40°.

[0019] Compared with traditional elastic locking mechanisms, this utility model has the following advantages:

[0020] This invention provides a V-shaped elastic locking mechanism for triangular manhole covers. Compared with traditional C-type and L-type elastic locking mechanisms, this V-shaped elastic locking mechanism has a significant advantage in terms of space utilization. Its compact structural design allows for flexible arrangement within the limited installation space of triangular manhole covers, greatly expanding the applicability of the elastic locking mechanism in triangular manhole cover applications.

[0021] This application significantly increases the total elastic deformation of the locking arm by incorporating a first and a second arc-shaped arm. Simultaneously, this design effectively disperses deformation stress, reducing the risk of plastic deformation due to excessive deformation at a single location, and greatly improving the service life and safety performance of the locking arm.

[0022] This application uses left and right limiting platforms to precisely limit the locking head, effectively restricting its lateral displacement under force. This largely solves the deflection problem when locking triangular manhole covers, ensuring a uniform gap between the manhole cover and the base, and further improving the safety and stability of the manhole cover. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0024] Figure 1 A perspective view of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0025] Figure 2 A top view of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0026] Figure 3 A front view of a triangular manhole cover elastic locking mechanism provided in an embodiment of this utility model;

[0027] Figure 4 A schematic diagram of the overall structure of the elastic lock mechanism for a triangular manhole cover provided in this embodiment of the present invention;

[0028] Figure 5 A schematic diagram of the overall structure of the locking groove of a triangular manhole cover elastic locking mechanism provided in an embodiment of this utility model;

[0029] Figure 6 A schematic diagram of the lock head structure of a triangular manhole cover elastic lock mechanism provided for an embodiment of this utility model;

[0030] Figure 7 A schematic diagram of the locking groove of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0031] Figure 8 A schematic diagram of the locking surface of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0032] Figure 9 A schematic diagram of the locking state of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0033] Figure 10 A schematic diagram of the root end face and front end face of a triangular manhole cover elastic locking mechanism provided for an embodiment of this utility model;

[0034] In the diagram: 1-Elastic lock; 2-Locking groove; 21-Locking surface; 211-Upper locking surface; 212-Main locking surface; 213-Lower locking surface; 22-Left limiting platform; 23-Right limiting platform; 3-Locking arm; 31-Connecting arm; 32-Main elastic arm; 33-First arc arm; 34-Secondary elastic arm; 35-Second arc arm; 36-Fixed arm; 37-Root end face; 38-Front end face; 4-Locking head; 41-Upper inclined surface; 42-Lower inclined surface; 43-Locking tip arc; 5-Bearing rib; 6-Short side; 7-Seat surface. Detailed Implementation

[0035] The specific embodiments of this utility model will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this utility model, but are not intended to limit its scope.

[0036] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0037] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0038] In the description of this application, it should be noted that, unless otherwise expressly 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 between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] See Figure 1-7 As shown, this embodiment provides a triangular manhole cover elastic locking mechanism, including an elastic lock 1 and a locking groove 2.

[0040] Specifically, the elastic lock 1 is V-shaped and is located on the short side of the triangular manhole cover.

[0041] Specifically, the elastic lock 1 includes a locking arm 3 and a locking head 4. The locking arm 3 includes a connecting arm 31, a main elastic arm 32, a first arc arm 33, a secondary elastic arm 34, a second arc arm 35, and a fixing arm 36. The fixing arm 36 is perpendicularly connected to the load-bearing rib 5 of the triangular manhole cover. One side of the second arc arm 35 is engaged with the fixing arm 36, and the side of the second arc arm 35 away from the fixing arm 36 is engaged with the secondary elastic arm 34. The secondary elastic arm 34 is parallel to the short side 6 of the triangular manhole cover in the horizontal direction. One side of the first arc arm 33 is engaged with the secondary elastic arm 34, and the side of the first arc arm 33 away from the secondary elastic arm 34 is engaged with the main elastic arm 32. One side of the connecting arm 31 is engaged with the main elastic arm 32, and the side of the connecting arm 31 away from the main elastic arm 32 is engaged with the locking head 4. The connecting arm 31 is perpendicular to the secondary elastic arm 34.

[0042] Specifically, a buckle is provided on one side of the long side of the triangular manhole cover, and a slot is provided on the side of the manhole base away from the locking groove to cooperate with the buckle. The buckle and the slot cooperate with each other to fix the triangular manhole cover.

[0043] Understandably, the fixed arm 36 is tightly connected to the load-bearing rib 5 of the triangular manhole cover in a perpendicular state, providing a stable fixed foundation for the locking arm 3; one end of the second arc arm 35 is connected to the fixed arm 36, and the other end is connected to the secondary elastic arm 34, forming a stable structural transition; the secondary elastic arm 34 is parallel to the short side 6 of the triangular manhole cover in the horizontal direction, ensuring the structural stability and force rationality of the locking arm 3 in this direction; one end of the first arc arm 33 is tightly connected to the secondary elastic arm 34, and the other end is seamlessly connected to the main elastic arm 32, enabling them to work together to achieve elastic deformation; one end of the connecting arm 31 is tightly connected to the main elastic arm 32, and the other end is firmly connected to the lock head 4, transmitting force between the lock head 4 and the main elastic arm 32; the connecting arm 31 and the secondary elastic arm 34 are perpendicular to each other, further enhancing the structural stability and mechanical performance of the locking arm 3.

[0044] Specifically, the locking groove 2 is provided on the well base and located below the sitting surface 7 of the well base. The locking groove 2 is composed of a locking surface 21, a left limiting platform 22 and a right limiting platform 23.

[0045] It is understandable that the locking groove 2 is an integral part of the overall structure of the well seat. The locking groove 2 includes a locking surface 21 and two limiting platforms on the left and right. The locking surface 21 is the working surface inside the locking groove 2. The left limiting platform 22 and the right limiting platform 23 are used to limit the locking head 4.

[0046] As can be seen, this utility model, by employing a V-shaped elastic lock 1 mechanism, can be flexibly arranged within the limited installation space of the triangular manhole cover, greatly expanding the applicability of the elastic lock mechanism in triangular manhole cover application scenarios. Furthermore, this utility model adopts a two-stage elastic deformation structure, significantly increasing the total elastic deformation of the lock arm 3 by setting the first arc arm 33 and the second arc arm 35. Through the precise positioning of the lock head 4 by the left limiting platform 22 and the right limiting platform 23, the lateral displacement of the lock head 4 under force is effectively limited, thus largely solving the deflection problem when the triangular manhole cover is locked.

[0047] See Figure 1-4 As shown in Figure 10, in some embodiments of this application, the locking arm 3 is a structure with one end suspended, the joint surface of the fixed arm 36 and the load-bearing rib 5 is the root end face 37 of the locking arm 3, and the joint surface of the connecting arm 31 and the lock head 4 is the front end face 38 of the locking arm 3.

[0048] It is understandable that the fixed arm 36 is connected to the load-bearing rib 5 through a joint surface. Except for the fixed connection between the fixed arm 36 and the load-bearing rib 5, the rest of the locking arm 3 is in a suspended state, that is, the end of the locking arm 3 away from the load-bearing rib is in a suspended state. This suspended structure design ensures both the elastic deformation freedom of the locking arm 3 and the stability of the structure.

[0049] Specifically, the height of the root end face 37 is higher than the height of the front end face 38, and the thickness of the root end face 37 is greater than the thickness of the front end face 38.

[0050] Understandably, from the root end face 37 to the front end face 38, the height of the locking arm 3 gradually decreases, and the thickness of the locking arm 3 gradually thins. This dual-gradient structural design of the locking arm 3, with its gradual change in both height and thickness, has a significant impact on the elastic deformation behavior of the locking arm 3, enabling it to exhibit a specific deformation sequence and mechanical response when subjected to compressive force.

[0051] See Figure 1-4 As shown, in some embodiments of this application, the first arc arm 33 and the second arc arm 35 are both arc-shaped structures, and the arc length of the first arc arm 33 is greater than the arc length of the second arc arm 35.

[0052] It is understandable that this application follows the principle that the greater the arc length, the easier it is to undergo elastic deformation. Since the arc length of the first arc arm 33 is greater than that of the second arc arm 35, when the locking arm 3 is compressed, the first arc arm 33 will preferentially undergo elastic deformation, providing an orderly starting stage for the overall elastic deformation of the locking arm 3.

[0053] See Figure 6 As shown, in some embodiments of this application, the lock head 4 is composed of an upper inclined surface 41, a lower inclined surface 42, and a lock tip arc 43.

[0054] Specifically, the lock head 4 is ">" shaped, the lock head 4 is engaged with the connecting arm 31 of the lock arm 3, and the width of the lock head 4 is twice the width of the front end face 38.

[0055] Understandably, the width of the lock head 4 is set to be twice the width of the front face 38 and twice the minimum width of the connecting arm 31. This width design not only ensures a stable connection between the lock head 4 and the connecting arm 31, but also plays a key role in the force and positioning of the lock head 4 during the locking process.

[0056] See Figure 7-8 As shown in some embodiments of this application, the locking surface 21 is a segmented inclined surface, which is composed of an upper locking surface 211, a main locking surface 212 and a lower locking surface 213, and all three surfaces are at a certain angle to the vertical direction.

[0057] See Figure 6-9 As shown, in some embodiments of this application, the width of the locking surface 21 is wider than the width of the lock head 4, the upper locking surface 211 and the main locking surface 212 are effective working surfaces, and the lower locking surface 213 is a protective plane.

[0058] Understandably, the width of the locking surface 21 is slightly wider than the width of the lock head 4, providing adequate space for the movement and positioning of the lock head 4 during the locking process, ensuring a smooth locking process.

[0059] Understandably, the upper locking surface 211 and the main locking surface 212, as effective working surfaces, can directly bear the main force during the locking process, achieving a tight connection between the manhole cover and the manhole base. The lower locking surface 213, as a protective surface, can effectively prevent the lock head 4 from jamming when the locking arm 3 fails due to plastic deformation caused by long-term use or accidental events, ensuring that the manhole cover still has a certain opening and closing function.

[0060] See Figure 5-9 As shown, in some embodiments of this application, the left limiting platform 22 and the right limiting platform 23 are disposed on both sides of the locking surface 21 to limit the left and right movement of the lock head 4 and to limit the deflection of the triangular manhole cover.

[0061] It is understandable that the left limiting platform 22 and the right limiting platform 23 are respectively distributed on both sides of the locking surface 21. When the lock head 4 contacts the locking surface 21, the left limiting platform 22 and the right limiting platform 23 can not only restrict the left and right movement of the lock head 4, ensuring that the lock head 4 is always within the range of the locking surface 21 and preventing it from coming out, but also effectively restrict the triangular manhole cover from deflecting at a large angle when locked, thereby ensuring that the gap between the manhole cover and the manhole seat is uniform and improving the overall stability and safety of the manhole cover.

[0062] See Figure 7-9 As shown, in some embodiments of this application, the upper locking surface 211 has an angle of 5° with the vertical direction, the main locking surface 212 has an angle of 20° with the vertical direction, and the lower locking surface 213 has an angle of 50° with the vertical direction.

[0063] It is understandable that the segmented inclined surface design and the setting of different angles in this application are closely coordinated with the movement trajectory and force conditions of the lock head 4 during the locking process, so as to achieve an efficient and reliable locking function.

[0064] See Figure 1 , 2 As shown in Figures 4 and 5, in some embodiments of this application, the angle between the main elastic arm 32 and the secondary elastic arm 34 is 40°.

[0065] It is understandable that a specific angle of 40° is formed between the main elastic arm 32 and the secondary elastic arm 34. This angle design has been carefully considered and helps to optimize the elastic deformation performance and mechanical transmission efficiency of the locking arm 3 under force.

[0066] As can be seen, compared with the traditional C-type and L-type elastic lock mechanisms, the V-type elastic lock mechanism of this invention has a significant advantage in terms of space occupancy. Its compact structural design allows it to be flexibly arranged within the limited installation space of triangular manhole covers, greatly expanding the applicability of the elastic lock mechanism in triangular manhole cover application scenarios.

[0067] This application significantly increases the total elastic deformation of the locking arm 3 by setting a first arc arm 33 and a second arc arm 35. At the same time, this design effectively disperses deformation stress, reduces the risk of plastic deformation due to excessive deformation at a single location, and greatly improves the service life and safety performance of the locking arm 3.

[0068] This application can precisely limit the locking head 4 through the left limiting platform 22 and the right limiting platform 23, which can effectively limit the left and right displacement of the locking head 4 when under force, thereby largely solving the deflection problem when the triangular manhole cover is locked, ensuring that the gap between the manhole cover and the manhole seat is uniform, and further improving the safety and stability of the manhole cover.

[0069] The locking principle of the triangular manhole cover elastic locking mechanism provided by this utility model is as follows: When the manhole cover is locked, the locking tip arc 43 of the lock head 4 first contacts the upper locking surface 211 of the locking surface 21 of the manhole seat. Under the action of vertical downward pressure, the lock head 4 slides downward and inward along the upper locking surface 211. During this process, the lock head 4 squeezes the locking arm 3, causing the locking arm 3 to undergo elastic deformation.

[0070] The elastic deformation process of the locking arm 3 exhibits a specific sequence and stages: as the locking head 4 moves inward, the first arc arm 33 first undergoes elastic deformation, causing the angle between the main elastic arm 32 and the secondary elastic arm 34 to gradually decrease. When the elastic deformation of the first arc arm 33 reaches a certain level, as the locking head 4 continues to move, the second arc arm 35 begins to undergo elastic deformation, causing the angle between the secondary elastic arm 34 and the fixed arm 36 to gradually decrease.

[0071] As the locking tip arc 43 continues to slide downwards, reaching the intersection of the upper locking surface 211 and the main locking surface 212, the locking arm 3 reaches its maximum elastic deformation. At this point, the locking arm 3 stores the maximum elastic potential energy.

[0072] As the locking tip arc 43 continues to slide downward, passing the intersection point, and contacts the main locking surface 212 and continues to slide down, the elastic deformation of the second arc arm 35 of the locking arm 3 is gradually released, and the elastic potential energy begins to be converted into a force that causes the locking head 4 to continue to slide down and maintain the locking state.

[0073] When the locking tip arc 43 slides down the main locking surface 212 a certain distance to reach the maximum sliding position, the entire locking process is completed. At this time, the elastic deformation of the second arc arm 35 of the locking arm 3 is completely released, and the secondary elastic arm 34 returns to its initial position; while the first arc arm 33 is still in an elastic deformation state. Due to the reaction force generated by the elastic deformation of the locking arm 3, the lock head 4 is pressed tightly against the main locking surface 212, thereby achieving a firm lock between the manhole cover and the manhole base.

[0074] When the manhole cover is in the locked state, due to the presence of the left limiting platform 22 and the right limiting platform 23, the lock head 4 is strictly confined within the locking groove 2, and there will be no left or right displacement, which effectively ensures the stability and reliability of the manhole cover during long-term use.

[0075] It will be understood by those skilled in the art that the above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A triangular manhole cover elastic locking mechanism, characterized in that, include: The resilient lock is V-shaped and is located on the short side of the triangular manhole cover. The resilient lock includes a locking arm and a locking head. The locking arm includes a connecting arm, a main elastic arm, a first arc arm, a secondary elastic arm, a second arc arm, and a fixed arm. The fixed arm is perpendicularly connected to the load-bearing rib of the triangular manhole cover. One side of the second arc arm is engaged with the fixed arm, and the side of the second arc arm away from the fixed arm is engaged with the secondary elastic arm. The secondary elastic arm is parallel to the short side of the triangular manhole cover in the horizontal direction. One side of the first arc arm is engaged with the secondary elastic arm, and the side of the first arc arm away from the secondary elastic arm is engaged with the main elastic arm. One side of the connecting arm is engaged with the main elastic arm, and the side of the connecting arm away from the main elastic arm is engaged with the lock head. The connecting arm is perpendicular to the secondary elastic arm. The locking groove is provided on the well base and consists of a locking surface, a left limiting platform, and a right limiting platform.

2. The elastic locking mechanism for a triangular manhole cover according to claim 1, characterized in that, The locking arm is a structure with one end suspended. The joint surface between the fixed arm and the load-bearing rib is the root end face of the locking arm. The joint surface between the connecting arm and the lock head is the front end face of the locking arm. The height of the root end face is higher than the height of the front end face, and the thickness of the root end face is greater than the thickness of the front end face.

3. The elastic locking mechanism for a triangular manhole cover according to claim 1, characterized in that, Both the first and second arc arms are arc-shaped structures, and the arc length of the first arc arm is greater than that of the second arc arm.

4. The elastic locking mechanism for a triangular manhole cover according to claim 2, characterized in that, The lock head is composed of an upper bevel, a lower bevel, and a lock tip arc. The lock head is engaged with the connecting arm of the lock arm, and the width of the lock head is twice the width of the front end face.

5. The elastic locking mechanism for a triangular manhole cover according to claim 1, characterized in that, The locking surface is a segmented inclined surface, consisting of an upper locking surface, a main locking surface, and a lower locking surface.

6. The elastic locking mechanism for a triangular manhole cover according to claim 5, characterized in that, The width of the locking surface is wider than the width of the lock head. The upper locking surface and the main locking surface are effective working surfaces, and the lower locking surface is a protective plane.

7. The elastic locking mechanism for a triangular manhole cover according to claim 5, characterized in that, The left and right limiting platforms are located on both sides of the locking surface to restrict the left and right movement of the lock head and to restrict the deflection of the triangular manhole cover.

8. The elastic locking mechanism for a triangular manhole cover according to claim 5, characterized in that, The upper locking surface has an angle of 5° with the vertical direction, the main locking surface has an angle of 20° with the vertical direction, and the lower locking surface has an angle of 50° with the vertical direction.

9. The elastic locking mechanism for a triangular manhole cover according to claim 1, characterized in that, The angle between the main elastic arm and the secondary elastic arm is 40°.

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