Inspection well cover assembly

Abstract

The invention discloses an inspection well cover assembly which comprises a well ring of a cylindrical structure with the two ends open. The well lid is embedded in and slidably arranged on the opening in the top end of the well ring in the axial direction of the well ring; wherein the well ring comprises an upper ring body and a lower ring body, the bottom end of the upper ring body is detachably connected to the top end of the lower ring body, a plurality of abutting blocks used for supporting the well cover are arranged on the inner side face of the upper ring body, connecting blocks corresponding to the abutting blocks one to one are arranged on the bottom face of the well cover, and the connecting blocks are connected to the corresponding abutting blocks in a sliding mode. And a plurality of grooves for erecting and placing a lifting device for driving the well lid to lift are formed in the lower ring body. According to the inspection well cover, the convenience of installation and follow-up maintenance and the use safety are improved, and the limitation of road installation space on inspection well cover installation construction is reduced.

Description

Technical Field

[0001] This invention relates to the field of manhole covers, and more specifically to a manhole cover assembly. Background Technology

[0002] Manhole covers are the covering components that cover the openings of manholes on the road surface. They typically consist of two parts: a manhole ring and a manhole cover. The manhole ring is installed on the manhole opening, and the manhole cover is embedded or hinged within the cavity of the manhole ring. Because conventional manhole covers have limited drainage openings, rainwater often cannot drain from the road in time during heavy rains, resulting in water accumulation and causing inconvenience to pedestrians and vehicles.

[0003] A liftable manhole cover is a municipal facility that can automatically raise and lower the manhole cover. Typically, a container is used to collect rainwater falling into the manhole. Once the weight reaches a certain level, the container can pull the lifting device on the manhole cover under the action of gravity, thereby driving the manhole cover to rise and increasing the water ingress area on the manhole cover.

[0004] For stability considerations when lifting manhole covers, multi-point synchronous lifting is often used. This involves installing multiple lifting devices on the manhole cover, which are simultaneously pulled by a container to push the edges of the cover, thus lifting it. Since the manhole cover is buried in the road, to ensure the effectiveness and lifespan of the lifting devices, they are often concealed within the sidewalls of the cover. This significantly increases the thickness of the sidewalls, thereby increasing the overall diameter of the manhole cover. This greatly restricts installation due to road space constraints and also increases the difficulty of manufacturing the cover and maintaining and repairing it. While some lift-type manhole covers use a center-lifting mechanism, this integrates the lifting device into the cover itself. This modular structure can affect the load-bearing capacity of the cover, and the support provided by the manhole casing can also impact the stability of the lifting device. Summary of the Invention

[0005] The purpose of this invention is to provide a manhole cover assembly that can support both the manhole cover and the lifting device in a lifting manhole cover, thereby improving the convenience of installation and subsequent maintenance, as well as the safety of use, and reducing the limitations of road installation space on manhole cover installation.

[0006] The technical solution adopted by the present invention to solve the above problems is: A manhole cover assembly, comprising: A well ring is a cylindrical structure open at both ends; The manhole cover is embedded in and slides along the axis of the manhole ring on the opening at the top of the manhole ring, and has several rainwater holes. The well ring includes an upper ring and a lower ring. The bottom of the upper ring is detachably connected to the top of the lower ring. The inner side of the upper ring is provided with several abutment blocks for supporting the well cover. Each abutment block is arranged at an equal angle around the central axis of the upper ring. The bottom surface of the well cover is provided with connecting blocks that correspond one-to-one with the abutment blocks. The connecting blocks are slidably connected to the corresponding abutment blocks. The lower ring is provided with several grooves for mounting and placing a lifting device for driving the well cover to rise. The grooves are located between two adjacent abutment blocks and are arranged at an equal angle around the central axis of the lower ring.

[0007] As a further improvement to the above technical solution, the upper ring body is made of ductile iron and a first circular ring piece is fitted on its top and integrally connected thereto. The first circular ring piece is perpendicular to the upper ring body and the top surfaces of the two are on the same horizontal plane. A decorative groove is opened on the top surface of the first circular ring piece, and a first pattern structure is provided in the decorative groove. The top surface of the first pattern structure is on the same horizontal plane as the top surface of the upper ring body. The bottom surface of the first circular ring piece is connected to the outer surface of the upper ring body through several triangular support pieces. Each support piece is arranged at an equal angle around the central axis of the first circular ring piece. A filling groove is opened on the bottom surface of the first circular ring piece between adjacent support pieces.

[0008] As a further improvement to the above technical solution, the lower ring body is made of ductile iron and a second circular ring piece is sleeved and integrally connected to its bottom end. The second circular ring piece is perpendicular to the lower ring body and the bottom surfaces of both are on the same horizontal plane. The top surface of the second circular ring piece is connected to the outer surface of the lower ring body through several triangular reinforcing pieces. Each reinforcing piece is arranged at equal angles around the central axis of the second circular ring piece. A first groove is formed on the top surface of the second circular ring piece between adjacent reinforcing pieces. A second groove is formed on the bottom surface of the second circular ring piece. Several through holes are formed in the first groove. The first groove and the second groove are connected through the through holes. Several support blocks are provided on the inner surface of the lower ring body, arranged at equal angles around its central axis. Grooves are formed on the top surface of the support blocks.

[0009] As a further improvement to the above technical solution, the bottom end of the upper ring body and the top end of the lower ring body are connected by several docking units. Each docking unit is arranged at an equal angle around the central axis of the upper ring body. Each docking unit includes two docking blocks, which are integrally connected to the sides of the bottom end of the upper ring body and the top end of the lower ring body, respectively. The docking blocks are provided with docking holes for the rod of the bolt to pass through.

[0010] As a further improvement to the above technical solution, the lower ring body is made of concrete and has several bolts on its top surface. Each bolt is arranged at an equal angle around the central axis of the lower ring body. The outer side of the upper ring body has mounting blocks that correspond one-to-one with the bolts. The mounting blocks have mounting holes for the shanks of the bolts to pass through. There are lifting rings between adjacent bolts. There are at least three lifting rings and each lifting ring is arranged at an equal angle around the central axis of the lower ring body. Grooves are formed on the side of the lower ring body.

[0011] As a further improvement to the above technical solution, an extension block is integrally connected to the outer surface of the lower ring body. The extension block is made of concrete and is in the shape of a regular square prism. Several water collection grooves are opened on the top surface of the extension block. Each water collection groove is arranged at an equal angle around the central axis of the lower ring body. A drainage channel corresponding to each water collection groove is opened on the lower ring body. The drainage channel is inclined relative to the lower ring body. The water collection grooves and the cavity of the lower ring body are connected through the drainage channel. The bottom end of the drainage channel is lower than the bottom end of the groove.

[0012] As a further improvement to the above technical solution, the connecting block is provided with a receiving groove for the abutment block to be inserted from bottom to top, the bottom end of the abutment block is provided with a sloping structure, and the top surface of the abutment block is provided with a rubber block. When the manhole cover is embedded in the manhole ring, the abutment block is located in the receiving groove and the rubber block is sandwiched between the abutment block and the connecting block.

[0013] As a further improvement to the above technical solution, the abutment block is provided with a slot for the connecting block to be inserted from top to bottom. The slot is in the shape of an inverted frustum, and the connecting block is in the shape of an inverted cone. A rubber sleeve that is adapted to it is provided in the slot. When the manhole cover is embedded in the manhole ring, the connecting block passes through the rubber sleeve and is located in the slot, and the rubber sleeve is sandwiched between the abutment block and the connecting block.

[0014] As a further improvement to the above technical solution, the top surface of the manhole cover is provided with a second pattern structure. When the manhole cover is embedded in the manhole ring, the top surface of the manhole cover is lower than the top surface of the manhole ring, and the top surface of the second pattern structure is on the same horizontal plane as the top surface of the manhole ring.

[0015] As a further improvement to the above technical solution, the manhole cover is made of ductile iron and has an extension pipe integrally connected to its bottom surface. The extension pipe and the manhole cover are perpendicular and their central axes are on the same straight line. The side of the extension pipe and the bottom surface of the manhole cover are connected by several triangular connecting pieces, and each connecting piece is arranged at an equal angle around the central axis of the manhole cover.

[0016] Compared with the prior art, the present invention has the following advantages and effects: This invention, through the combined structure of the manhole ring, achieves the effect of supporting both the manhole cover and the lifting device separately in a lifting manhole cover. This ensures both the load-bearing capacity of the integrated manhole cover structure and the stability of the lifting device. Furthermore, since the lifting device can be directly installed within the cavity of the manhole ring, it improves the convenience of installation and subsequent maintenance, and reduces the impact on the thickness of the manhole ring wall. This reduces the limitations imposed by road space on manhole cover installation, and also helps to prevent people from falling into the manhole, thus improving the safety of manhole cover use. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of Embodiment 1.

[0018] Figure 2 yes Figure 1 The diagram shows the structure of the well ring.

[0019] Figure 3 yes Figure 1 The diagram shows a partial structural diagram of the connection between the manhole cover and the manhole ring.

[0020] Figure 4 yes Figure 2 The diagram shows the structure of the upper ring.

[0021] Figure 5 yes Figure 4 A partial structural schematic diagram of the first annular plate shown.

[0022] Figure 6 yes Figure 2 The diagram shows the structure of the lower ring.

[0023] Figure 7 yes Figure 6 A partial structural schematic diagram of the second annular plate shown.

[0024] Figure 8 yes Figure 1 The diagram shows the structure of the manhole cover from one perspective.

[0025] Figure 9 yes Figure 1 The diagram shows the structure of the manhole cover from the second perspective.

[0026] Figure 10 This is a schematic diagram of the lifting device used in Embodiment 1.

[0027] Figure 11 This is a schematic side view of the lifting device used in Embodiment 1.

[0028] Figure 12 This is a partial structural diagram of the upper ring body in Example 2.

[0029] Figure 13 This is a partial structural diagram of the manhole cover in Example 2.

[0030] Figure 14 This is a partial structural diagram of the connection between the manhole cover and the upper ring body in Embodiment 2.

[0031] Figure 15 This is a schematic diagram of the structure of Embodiment 3.

[0032] Figure 16 yes Figure 15 The diagram shows the structure of the lower ring.

[0033] Figure 17 This is a schematic diagram of the structure of Embodiment 4.

[0034] Figure 18 yes Figure 17 The diagram shows the structure of the lower ring.

[0035] The components include: well ring 1, upper ring body 11, lower ring body 12, groove 13, docking unit 14, docking block 15, docking hole 16, well cover 2, rainwater hole 21, second patterned structure 22, extension pipe 23, connecting piece 24, abutment block 31, connecting block 32, receiving groove 33, inclined structure 34, rubber block 35, slot 36, rubber sleeve 37, first annular piece 4, decorative groove 41, first patterned structure 42, support piece 43, and filling groove 44. Second circular ring 5, reinforcing plate 51, first groove 52, second groove 53, through hole 54, support block 55, bolt 61, mounting block 62, mounting hole 63, lifting ring 64, extension block 71, water collection tank 72, drainage channel 73, bracket 81, extension part 82, lifting rod 83, drive rod 84, waist-shaped hole 85, hinge bolt 86, hanging hole 87, hemispherical surface 91, limiting groove 92, hook hole 93, protruding post 94, disassembly hole 95. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. The following embodiments are explanations of the present invention, but the present invention is not limited to the following embodiments.

[0037] Example 1.

[0038] See Figures 1-11This embodiment discloses a manhole cover assembly, including a manhole ring 1 and a manhole cover 2. The manhole ring 1 is a cylindrical structure with openings at both ends. The manhole cover 2 is embedded in and slidably disposed on the opening at the top of the manhole ring 1 along the axial direction of the manhole ring 1. The manhole cover 2 has several rainwater holes 21. The manhole ring 1 includes an upper ring body 11 and a lower ring body 12. The bottom end of the upper ring body 11 is detachably connected to the top end of the lower ring body 12. Since the upper ring body 11 and the lower ring body 12 can be manufactured separately, the manufacturing difficulty of the manhole ring 1 is reduced while ensuring the structural integrity of the manhole ring 1, thereby ensuring the safety of the manhole cover in a lift-type manhole cover. The upper ring 11 has a number of abutment blocks 31 on its inner side for supporting the manhole cover 2. Each abutment block 31 is arranged at equal angles around the central axis of the upper ring 11. The bottom surface of the manhole cover 2 has a connecting block 32 that corresponds to each abutment block 31. The connecting block 32 is slidably connected to the corresponding abutment block 31. The lower ring 12 has a number of grooves 13 for mounting and placing the lifting device for driving the manhole cover 2. The grooves 13 are located between two adjacent abutment blocks 31 and each groove 13 is arranged at equal angles around the central axis of the lower ring 12.

[0039] When installing a manhole cover, the lower ring 12 is placed on the manhole base, and then the upper ring 11 is placed and installed on the lower ring 12 to form the manhole ring 1. At this time, the cavity of the manhole ring 1 is connected to the cavity of the manhole base. Then, the lifting device is placed in and erected on the lower ring 12 through the groove 13 to complete the installation of the lifting device. Then, the manhole cover 2 is installed on the upper ring 11 to complete the assembly of the manhole cover. Finally, after backfilling the soil and paving the road, the manhole cover is embedded and fixed on the road surface, completing the installation of the manhole cover on the road.

[0040] In this embodiment, the lifting device uses a lever to drive the manhole cover 2. The lifting device includes a bracket 81, with an extension 82 corresponding to the groove 13. A lifting rod 83 is slidably mounted on the bracket 81 along its axial direction, and the central axes of the two are on the same straight line. A driving rod 84 is provided on the bottom surface of the extension 82, and the two ends of the driving rod 84 are hinged to the extension 82. A waist-shaped hole 85 is opened on the inner end of the driving rod 84, and the waist-shaped hole 85 is connected to the side of the bottom end of the lifting rod 83 by a hinge bolt 86. A hanging hole 87 for suspending a water container is opened on the outer end of the driving rod 84. Figure 10 , Figure 11 As shown in the image.

[0041] When rainwater enters the manhole and is collected by the water receiving container, the manhole cover 2 and the manhole ring 1 are in a relatively static state when the inflow of water into the container is less than the outflow. However, when the rainfall intensifies and the inflow of water into the container exceeds the outflow, the weight of the container increases. This causes the drive rod 84 to rotate relative to the support 81 under the influence of gravity, which in turn causes the lifting rod 83 to move vertically upward relative to the support 81. This lifts the manhole cover 2 to expand the water inflow area and achieves the goal of rapidly reducing rainwater on the road surface. Furthermore, when the rainfall intensifies and the inflow of water into the container is less than the outflow, the weight of the container gradually decreases to its initial weight, and the manhole cover 2 gradually returns to its original position under the influence of gravity.

[0042] During the above process, as the top of the lifting rod 83 is lifted against the center of the manhole cover 2, to ensure the stability of the drive and reduce the risk of damage to the lifting rod 83 caused by the manhole cover 2 tilting relative to the lifting rod 83 under external force during the lifting process, the end face of the top of the lifting rod 83 is hemispherical 91. The manhole cover 2 is provided with a limiting groove 92 that matches the top of the lifting rod 83. A tension spring is provided between the extension 82 and the manhole cover 2. A hook hole 93 is provided on the outer end of the extension 82 for one end of the tension spring to hook onto. The manhole cover 2 is provided with a protrusion 94 for the other end of the tension spring to hook onto. A disassembly hole 95 is provided on the manhole cover 2 at the position opposite to the protrusion 94. Figure 9 , Figure 11 As shown in the image.

[0043] See Figure 2 The bottom end of the upper ring body 11 and the top end of the lower ring body 12 are connected by a number of docking units 14. Each docking unit 14 is arranged at an equal angle around the central axis of the upper ring body 11. Each docking unit 14 includes two docking blocks 15. The two docking blocks 15 are integrally connected to the side of the bottom end of the upper ring body 11 and the top end of the lower ring body 12, respectively. The docking blocks 15 are provided with docking holes 16 for the rods of bolts to pass through, so that the corresponding docking blocks 15 on the upper ring body 11 and the lower ring body 12 can be connected by bolts, thereby fixing the upper ring body 11 and the lower ring body 12 into a whole.

[0044] See Figure 3 , Figure 4The connecting block 32 has a receiving groove 33 for the abutment block 31 to be inserted from bottom to top. The bottom end of the abutment block 31 has an inclined structure 34, forming a triangular support structure, which ensures the support effect of the manhole ring 1 on the manhole cover 2. The top surface of the abutment block 31 has a rubber block 35. When the manhole cover 2 is embedded in the manhole ring 1, the abutment block 31 is located in the receiving groove 33 and the rubber block 35 is sandwiched between the abutment block 31 and the connecting block 32, which increases the friction between the abutment block 31 and the connecting block 32 and increases the difficulty of relative movement between the manhole cover 2 and the manhole ring 1, thereby reducing the risk of abnormal noise caused by the collision between the manhole cover 2 and the manhole ring 1 due to pedestrians stepping on it or vehicles running over it.

[0045] See Figure 4 , Figure 5 The upper ring body 11 is made of ductile iron, and a first circular ring 4 is integrally connected to its top. The first circular ring 4 is perpendicular to the upper ring body 11, and the top surfaces of both are on the same horizontal plane, increasing the effective contact area for the road to support the upper ring body 11, thereby increasing the difficulty for the manhole cover 1 to sink into the road under external force. A decorative groove 41 is opened on the top surface of the first circular ring 4, and a first pattern structure 42 is provided in the decorative groove 41. The top surface of the first pattern structure 42 is on the same horizontal plane as the top surface of the upper ring body 11. While improving the visual effect of the exposed manhole cover on the road, it also increases friction and reduces rain damage. The manhole cover eliminates the risk of pedestrians or vehicles slipping, ensuring the safety of manhole cover use on roads. The bottom surface of the first circular ring 4 is connected to the outer surface of the upper ring 11 through several triangular support pieces 43. Each support piece 43 is arranged at an equal angle around the central axis of the first circular ring 4, which improves the structural stability between the first circular ring 4 and the upper ring 11. A filling groove 44 is provided on the bottom surface of the first circular ring 4 between adjacent support pieces 43, so that the upper ring 11 can be embedded in the road surface, thereby achieving the purpose of limiting the displacement of the upper ring 11 by the road and ensuring the stability of the manhole cover installation position on the road.

[0046] See Figure 6 , Figure 7The lower ring body 12 is made of ductile iron, and a second circular ring 5 is integrally connected to its bottom end. The second circular ring 5 is perpendicular to the lower ring body 12, and the bottom surfaces of both are on the same horizontal plane, which increases the effective contact area between the road and the lower ring body 12, thereby increasing the difficulty of the manhole ring 1 detaching from the road. The top surface of the second circular ring 5 is connected to the outer surface of the lower ring body 12 by several triangular reinforcing plates 51. Each reinforcing plate 51 is arranged at equal angles around the central axis of the second circular ring 5, which improves the structural stability between the second circular ring 5 and the lower ring body 12. A first groove 52 is provided between adjacent reinforcing plates 51, and a second groove 53 is provided on the bottom surface of the second annular plate 5. Several through holes 54 are provided in the first groove 52, and the first groove 52 and the second groove 53 are connected through the through holes 54, which improves the road's ability to restrict the displacement of the lower ring body 12. Several support blocks 55 are provided on the inner side of the lower ring body 12, arranged at equal angles around its central axis. The groove 13 is provided on the top surface of the support block 55, which not only ensures the wall thickness of the lower ring body 12, but also reduces the processing difficulty of the groove 13 on the lower ring body 12, and improves the manufacturing convenience of the lower ring body 12.

[0047] See Figure 8 The top surface of the manhole cover 2 is provided with a second pattern structure 22. When the manhole cover 2 is embedded in the manhole ring 1, the top surface of the manhole cover 2 is lower than the top surface of the manhole ring 1, and the top surface of the second pattern structure 22 is on the same horizontal plane as the top surface of the manhole ring 1. This not only improves the visual effect of the exposed manhole cover on the road, but also increases friction, reduces the risk of pedestrians or vehicles slipping due to the manhole cover in rainy weather, and ensures the safety of the use of manhole covers on the road.

[0048] See Figure 9 The manhole cover 2 is made of ductile iron and has an extension pipe 23 integrally connected to its bottom surface. The extension pipe 23 and the manhole cover 2 are perpendicular and their central axes are on the same straight line. The side of the extension pipe 23 and the bottom surface of the manhole cover 2 are connected by several triangular connecting pieces 24. Each connecting piece 24 is arranged at an equal angle around the central axis of the manhole cover 2, which enhances the structural strength of the manhole cover 2 and improves the load-bearing performance of the middle area of ​​the manhole cover 2.

[0049] Example 2.

[0050] See Figures 12-14The structure of this embodiment is basically the same as that of Embodiment 1, except that: the abutting block 31 is provided with a slot 36 for the connecting block 32 to be inserted from top to bottom. The slot 36 is in the shape of an inverted frustum, and the connecting block 32 is in the shape of an inverted cone. This can guide the positioning and installation of the manhole cover 2 on the manhole ring 1, and expand the effective contact area of ​​the manhole ring 1 to support the manhole cover 2, thereby improving the support effect of the manhole cover 2 and ensuring the load-bearing capacity of the manhole cover 2. The slot 36 is provided with a rubber sleeve 37 that is adapted to it. When the manhole cover 2 is embedded on the manhole ring 1, the connecting block 32 passes through the rubber sleeve 37 and is located in the slot 36. The rubber sleeve 37 is sandwiched between the abutting block 31 and the connecting block 32, which increases the friction between the abutting block 31 and the connecting block 32, thereby increasing the difficulty of relative movement between the manhole cover 2 and the manhole ring 1 and reducing the risk of abnormal noise caused by the collision between the manhole cover 2 and the manhole ring 1 due to pedestrians stepping on it or vehicles running over it.

[0051] Example 3.

[0052] See Figure 15 , Figure 16 The structure of this embodiment is basically the same as that of Embodiment 1 and Embodiment 2, except that: the lower ring body 12 is made of concrete and has several bolts 61 on its top surface. Each bolt 61 is arranged at equal angles around the central axis of the lower ring body 12. The outer side of the upper ring body 11 is provided with mounting blocks 62 corresponding to each bolt 61. The mounting blocks 62 have mounting holes 63 for the rods of the bolts 61 to pass through, so that the upper ring body 11 can be fixed to the lower ring body 12 by the bolts 61, which improves the convenience of assembling the manhole cover 1 and also reduces the manufacturing difficulty and cost of the lower ring body 12. There are lifting rings 64 between adjacent bolts 61. There are at least three lifting rings 64 and each lifting ring 64 is arranged at equal angles around the central axis of the lower ring body 12. When the manhole cover is installed in the manhole, the lower ring body 12 is moved and placed in the designated position by hoisting, which improves the convenience of manhole cover construction operation. The groove 13 is opened on the side of the lower ring body 12.

[0053] Example 4.

[0054] See Figure 17 , Figure 18The structure of this embodiment is basically the same as that of Embodiment 3, except that: an extension block 71 is integrally connected to the outer surface of the lower ring body 12. The extension block 71 is made of concrete and is in the shape of a regular square prism. Several water collection grooves 72 are formed on the top surface of the extension block 71. Each water collection groove 72 is arranged at an equal angle around the central axis of the lower ring body 12. A drainage channel 73 is formed on the lower ring body 12, corresponding to the water collection grooves 72. The drainage channel 73 is inclined relative to the lower ring body 12. The water collection grooves 72 and the cavity of the lower ring body 12 are connected through the drainage channel 73. This design allows rainwater that seeps through road cracks or the gaps between the road and the manhole cover to flow outward or collect in the water collection trough 72, which reduces the intensity of direct erosion on the soil around the manhole. This ensures the stability of the soil structure around the manhole and reduces the risk of the manhole cover sinking. At the same time, rainwater in the water collection trough 72 can also flow into the manhole through the diversion channel 73. The bottom of the diversion channel 73 is lower than the bottom of the trench 13, which reduces the impact of rainwater discharged from the diversion channel 73 on the lifting device and thus reduces the effectiveness of the lifting device.

[0055] The above description is merely illustrative of the invention. Those skilled in the art can make various modifications or additions to the described specific embodiments or use similar methods to replace them, as long as they do not depart from the content of this specification or exceed the scope defined by the claims, all of which should fall within the protection scope of this invention.

Claims

1. A manhole cover assembly, characterized in that, include: A well ring is a cylindrical structure open at both ends; The manhole cover is embedded in and slides along the axis of the manhole ring on the opening at the top of the manhole ring, and has several rainwater holes. The well ring includes an upper ring and a lower ring. The bottom of the upper ring is detachably connected to the top of the lower ring. The inner side of the upper ring is provided with several abutment blocks for supporting the well cover. Each abutment block is arranged at an equal angle around the central axis of the upper ring. The bottom surface of the well cover is provided with connecting blocks that correspond one-to-one with the abutment blocks. The connecting blocks are slidably connected to the corresponding abutment blocks. The lower ring is provided with several grooves for mounting and placing a lifting device for driving the well cover to rise. The grooves are located between two adjacent abutment blocks and are arranged at an equal angle around the central axis of the lower ring.

2. The manhole cover assembly according to claim 1, characterized in that: The upper ring is made of ductile iron and has a first circular ring piece integrally connected to its top. The first circular ring piece is perpendicular to the upper ring and the top surfaces of both are on the same horizontal plane. A decorative groove is formed on the top surface of the first circular ring piece, and a first pattern structure is formed in the decorative groove. The top surface of the first pattern structure is on the same horizontal plane as the top surface of the upper ring. The bottom surface of the first circular ring piece is connected to the outer surface of the upper ring through several triangular support pieces. Each support piece is arranged at an equal angle around the central axis of the first circular ring piece. A filling groove is formed on the bottom surface of the first circular ring piece between adjacent support pieces.

3. The manhole cover assembly according to claim 2, characterized in that: The lower ring body is made of ductile iron and has a second circular ring piece integrally connected to its bottom end. The second circular ring piece is perpendicular to the lower ring body and the bottom surfaces of both are on the same horizontal plane. The top surface of the second circular ring piece is connected to the outer surface of the lower ring body by several triangular reinforcing pieces. Each reinforcing piece is arranged at equal angles around the central axis of the second circular ring piece. A first groove is formed on the top surface of the second circular ring piece between adjacent reinforcing pieces. A second groove is formed on the bottom surface of the second circular ring piece. Several through holes are formed in the first groove. The first groove and the second groove are connected by through holes. Several support blocks are provided on the inner surface of the lower ring body, arranged at equal angles around its central axis. Grooves are formed on the top surface of the support blocks.

4. The manhole cover assembly according to claim 3, characterized in that: The bottom end of the upper ring and the top end of the lower ring are connected by several docking units. Each docking unit is arranged at an equal angle around the central axis of the upper ring. Each docking unit includes two docking blocks, which are integrally connected to the sides of the bottom end of the upper ring and the top end of the lower ring, respectively. The docking blocks are provided with docking holes for the rod of the bolt to pass through.

5. The manhole cover assembly according to claim 2, characterized in that: The lower ring is made of concrete and has several bolts on its top surface. The bolts are arranged at equal angles around the central axis of the lower ring. The outer side of the upper ring has mounting blocks that correspond to the bolts. The mounting blocks have mounting holes for the bolt shanks to pass through. There are lifting rings between adjacent bolts. There are at least three lifting rings and they are arranged at equal angles around the central axis of the lower ring. Grooves are formed on the side of the lower ring.

6. The manhole cover assembly according to claim 5, characterized in that: An extension block is integrally connected to the outer surface of the lower ring body. The extension block is made of concrete and is in the shape of a regular square prism. Several water collection grooves are opened on the top surface of the extension block. Each water collection groove is arranged at an equal angle around the central axis of the lower ring body. A drainage channel corresponding to each water collection groove is opened on the lower ring body. The drainage channel is inclined relative to the lower ring body. The water collection grooves and the cavity of the lower ring body are connected through the drainage channel. The bottom end of the drainage channel is lower than the bottom end of the groove.

7. The manhole cover assembly according to claim 1, characterized in that: The connecting block has a receiving groove for inserting the abutment block from bottom to top. The bottom end of the abutment block has a sloping structure, and the top surface of the abutment block has a rubber block. When the manhole cover is embedded in the manhole ring, the abutment block is located in the receiving groove and the rubber block is sandwiched between the abutment block and the connecting block.

8. The manhole cover assembly according to claim 1, characterized in that: The abutment block has a slot for the connecting block to be inserted from top to bottom. The slot is in the shape of an inverted frustum, and the connecting block is in the shape of an inverted cone. A rubber sleeve that fits the slot is provided inside the slot. When the manhole cover is installed on the manhole ring, the connecting block passes through the rubber sleeve and is located inside the slot, and the rubber sleeve is sandwiched between the abutment block and the connecting block.

9. The manhole cover assembly according to claim 1, characterized in that: The top surface of the manhole cover is provided with a second pattern structure. When the manhole cover is embedded in the manhole ring, the top surface of the manhole cover is lower than the top surface of the manhole ring, and the top surface of the second pattern structure is on the same horizontal plane as the top surface of the manhole ring.

10. The manhole cover assembly according to claim 1, characterized in that: The manhole cover is made of ductile iron and has an extension pipe integrally connected to its bottom surface. The extension pipe and the manhole cover are perpendicular and their central axes are on the same straight line. The side of the extension pipe and the bottom surface of the manhole cover are connected by several triangular connecting pieces, and each connecting piece is arranged at an equal angle around the central axis of the manhole cover.

Images