An anti-theft manhole cover

Abstract

The present invention discloses an anti-theft manhole cover, comprising a manhole cover, a manhole edge and a locking mechanism; the manhole cover is embedded in the middle position of the manhole edge, and a sealing ring is provided between the vertical contact surface with the manhole edge; the manhole edge is an annular structure, and the inner and outer walls are both provided with annular load-bearing platforms, and the inner wall below the load-bearing platform is provided with an internal thread connected to the underlying manhole wall; the locking mechanism comprises a locking rod that can lock the manhole cover and the manhole edge by horizontal movement or rotation, and a driving mechanism that drives the locking rod to move; the contact locking surface of the locking rod and the manhole cover or the manhole edge is a wedge-shaped surface. The anti-theft manhole cover simplifies the anti-theft structure, and the locking and anti-theft of the manhole cover and the manhole edge are achieved by the locking mechanism, the gap between the two is reduced, the noise generated by vibration is reduced, and the loss of the manhole cover is effectively avoided. In addition, the use of new materials effectively improves the rust resistance, corrosion resistance and sealing capabilities, and the weight is half that of a ductile iron manhole cover, and is suitable for use in valve wells, communication wells, optical cable laying wells and other occasions.

Description

Technical Field

[0001] The present invention relates to the technical field of municipal equipment, in particular to an anti-theft manhole cover. Background Art

[0002] Currently, manhole covers used in municipal projects are often round iron covers that are generally higher than the road surface. When the circular iron cover is driven over by cars for a long time, the uneven bosses on the manhole wall will cause the circular iron cover to vibrate. The vibration is loud, causing damage to the car and the road surface, and causing sound pollution. In addition, the simple design structure of the manhole cover makes it easy to be lifted and lost.

[0003] Chinese patent No. 201810566585.1 discloses a municipal engineering manhole cover that can be leveled and locked by adjusting the locking mechanism, solving the problems of vibration, noise, and easy loss of the manhole cover. However, the internal structure is relatively complex, requiring extensive debugging during installation, and the internal mechanism is prone to rust and failure during long-term use.

[0004] Therefore, a manhole cover should be developed that has a simple structure, is convenient for on-site use, can reduce vibration noise and prevent loss. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the existing defects and provide an anti-theft manhole cover with a simplified structure. The locking and anti-theft effect of the manhole cover and the manhole edge are achieved through a locking mechanism, the gap between the two is reduced, the noise generated by vibration is reduced, and the loss of the manhole cover is effectively avoided, which can effectively solve the problems in the background technology.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solutions: an anti-theft manhole cover, comprising a manhole cover, a manhole edge and a locking mechanism;

[0007] The manhole cover is embedded in the middle of the manhole edge, and a sealing ring is provided between the vertical contact surface with the manhole edge;

[0008] The well edge is an annular structure, and both the inner and outer walls are provided with an annular load-bearing platform, and the inner wall below the load-bearing platform is provided with an internal thread connected to the lower well wall;

[0009] The locking mechanism includes a locking rod capable of locking the manhole cover and the manhole edge by horizontal movement or rotation, and a driving mechanism for driving the locking rod to move;

[0010] The contact locking surface between the locking rod and the manhole cover or the manhole edge is a wedge-shaped surface.

[0011] As a preferred technical solution of the present invention, the locking lever includes a swing arm and a plug arm, the center position of the swing arm and the center position of the manhole cover are rotatably mounted along a vertical axis, the two ends of the swing arm are hinged with plug arms, the bottom wall edge position of the manhole cover is rotatably provided with a guide wheel, the guide wheel is an I-shaped wheel, and the free end of the plug arm passes through the middle of the two sets of guide wheels;

[0012] When the driving mechanism drives any set of swing arms or plug-in arms in the locking rod, it can drive the plug-in arms to feed along their own length direction and extend to the outside of the manhole cover to contact the bottom wall of the bearing platform on the edge of the manhole;

[0013] The contact surface between the free end of the plug-in arm and the bottom wall of the load-bearing platform is a wedge-shaped surface;

[0014] The locking rod adopts a three-link structure, in which the swing arm is hinged in the middle position, and the free ends of the remaining plug-in arms are limited by guide wheels. That is, the movement of one set of arms can drive the other two sets of arms to move synchronously, and the wedge-shaped surface contact between the plug-in arm and the bottom wall of the load-bearing platform is utilized. As the insertion amount of the plug-in arm increases, the vertical force between the plug-in arm and the load-bearing platform becomes greater. At this time, it helps to eliminate the gap between the manhole cover and the upper surface of the load-bearing platform, so that the manhole cover and the load-bearing platform fit tightly, so that when the manhole cover is crushed, no unnecessary vibration will be generated, thereby reducing noise. At the same time, the plug-in arm is combined with the load-bearing platform to limit the upward movement of the manhole cover, thereby playing an anti-theft role.

[0015] As a preferred technical solution of the present invention, the driving mechanism includes an operating wheel, which is coaxially fixed to one of the sets of guide wheels, and a mutually meshing gear and rack are provided between the operating wheel and the plug-in arm on the contact side;

[0016] Or the operating wheel is coaxially fixedly arranged with the middle axis of the swing arm.

[0017] As a preferred technical solution of the present invention, the operating wheel is rotatably mounted on the manhole cover;

[0018] The operating wheel passes through the manhole cover, and an operating hole adapted for an external operating tool is provided on the top of the operating wheel;

[0019] When the operating wheel directly passes through the manhole cover, it helps to reduce the complexity of the manhole cover structure, is beneficial to production and reduces costs, and is easy to operate. However, the top of the operating wheel is prone to wear and there are sealing problems with the side gaps.

[0020] Or the operating wheel does not penetrate the manhole cover, and a magnet is provided inside the operating wheel; when there is a rotating external magnet above the manhole cover, it can drive the operating wheel to rotate;

[0021] The use of built-in magnets can effectively solve the wear problem of the exposed position of the operating wheel and the sealing problem of the surrounding gaps. It is suitable for working conditions such as communication wells and water meter wells, and helps to prevent surface water from seeping into the well.

[0022] As a preferred technical solution of the present invention, a limit column for limiting the swing angle of the swing arm is provided at the bottom of the manhole cover. When the connecting arm moves along the axis to connect with the bearing platform at the edge of the manhole, the swing arm conflicts with the limit column.

[0023] As a preferred technical solution of the present invention, a double-layer load-bearing platform is provided on the inner wall of the well, and a gear ring is rotatably provided in the middle of the double-layer load-bearing platform; the locking rod includes a plurality of groups of arc-shaped rods, one end of each arc-shaped rod is rotatably mounted with the well along a vertical axis, and a gear meshing with the gear ring is coaxially fixedly provided at the rotating shaft;

[0024] The free ends of one group of arc-shaped rods are provided with lockers, and the free ends of the remaining arc-shaped rods are provided with locking hooks; when the free ends of the arc-shaped rods are all rotated to the center position of the well edge, the locking hooks can be locked with the lockers;

[0025] The edge of the manhole cover is provided with a downward flange, and the inner wall of the flange is provided with an annular groove or a plurality of groups of penetrating locking holes, and a locking cam is coaxially fixedly provided at the rotating shaft of the arc-shaped rod;

[0026] When the free end of the arc-shaped rod rotates to the center position of the well edge, the long diameter end of the locking cam can be inserted into the annular groove body or the locking hole of the well cover;

[0027] When the free end of the arc-shaped rod rotates to the edge of the well, the locking cam disengages from the annular groove body or the locking hole of the well cover;

[0028] The contact surface between the lower end surface of the cam and the annular groove body of the manhole cover or the bottom wall of the locking hole is a wedge-shaped surface;

[0029] Through the integrated design of the arc rod and the locking cam, while the manhole cover is locked, the arc rod is used to form an anti-fall net under the manhole cover, and the locking mechanism is integrated into the edge of the manhole, which reduces the structure of the manhole cover and reduces the cost of the manhole cover. When replacing the manhole cover, which is a consumable part, the cost can be reduced, and the locking mechanism and the anti-fall net are separated from the manhole cover. Even if the manhole cover is damaged, it will not affect the use of the anti-fall net.

[0030] As a preferred technical solution of the present invention, a sealed compartment is provided along the outer side of the well, and the drive mechanism is arranged in the sealed compartment. The drive mechanism is a magnetic transmission mechanism, which includes a driving wheel and a transmission wheel that rotate along a vertical axis and mesh with each other, and the transmission wheel meshes with the ring gear. A permanent magnet is provided on the top of the driving wheel. When the external permanent magnet above the sealed compartment rotates, it can drive the driving wheel to rotate;

[0031] Through the design of the magnetic transmission mechanism, there is no gap between the well edge and the surface of the manhole cover, which avoids the corrosion of the transmission mechanism by surface water and helps to increase the service life of the locking mechanism.

[0032] As a preferred technical solution of the present invention, the arc-shaped rod includes a set of main swing arms and a plurality of sets of slave swing arms. The locker is fixedly mounted on the free end of the main swing arm. The locker has a circular structure and a plurality of sets of locking grooves arranged in a circular array on the circumferential surface. When the free ends of the arc-shaped rods are rotated to the center of the well edge, the locking hooks of the slave swing arms are all engaged in the locking grooves.

[0033] When the arc rod rotates toward the center, the center positions of several groups of arc rods can interact with each other to avoid the problem of a single arc rod bending under the load, thereby playing the role of an anti-fall net, that is, when a heavy object falls from the top, it can receive or cushion the heavy object to prevent the heavy object from falling directly into the well; at the same time, when the locking cam and the manhole cover are unlocked, the arc rod can rotate in the opposite direction with the locking cam, the middle locker disengages, and the arc rod returns to the inner wall position of the well edge, without affecting the passability of the wellhead.

[0034] As a preferred technical solution of the present invention, protrusions and grooves for preventing mistakes are provided between the circumferential surface of the manhole cover and the inner wall of the manhole edge, and indicator marks for indicating the assembly direction are provided on the upper surfaces of the manhole cover and the manhole edge.

[0035] Compared with the prior art, the beneficial effects of the present invention are: the anti-theft manhole cover adopts the locking rod in the locking mechanism to translate or rotate to lock the manhole cover and the manhole edge, and utilizes the wedge structure between the contact surfaces to ensure the positive pressure between the locking surfaces, thereby improving the anti-theft ability, reducing the gap distance between the manhole cover and the manhole edge, thereby reducing vibration noise, and simplifying the structure of the locking mechanism, which is convenient for product use. By setting the operating wheel, it is convenient for on-site construction and subsequent maintenance. Compared with the existing integrated design of the manhole cover and the manhole edge, it is more convenient for the replacement and maintenance of the manhole cover of the wearing part, while playing an anti-theft role, it reduces the cost of use and improves the convenience of maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 It is a schematic diagram of the structure of the present invention;

[0037] Figure 2 Schematic diagram of the locking mechanism of the present invention;

[0038] Figure 3 It is a bottom schematic diagram of the present invention;

[0039] Figure 4 A schematic diagram of another embodiment of the present invention;

[0040] Figure 5A schematic diagram of a well edge according to another embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of a locking mechanism according to another embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the anti-falling principle of the locking mechanism of another embodiment of the present invention;

[0043] Figure 8 This is a schematic diagram of the locking principle of a locking mechanism according to another embodiment of the present invention.

[0044] In the figure: 1. Manhole cover; 101. Holding hole; 2. Manhole edge; 3. Operating wheel; 4. Connecting arm; 5. Swing arm; 6. Guide wheel; 7. Arc rod; 701. Main swing arm; 702. Slave swing arm; 703. Locking cam; 8. Magnetic transmission mechanism; 801. Driving wheel; 802. Transmission wheel; 9. Ring gear; 10. Limiting column. DETAILED DESCRIPTION

[0045] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0046] Example 1:

[0047] See also Figure 1-Figure 3 , the present invention provides a technical solution: an anti-theft manhole cover, comprising a manhole cover 1, a manhole edge 2 and a locking mechanism;

[0048] The manhole cover 1 is embedded in the middle of the manhole edge 2, and a sealing ring is provided between the vertical contact surface with the manhole edge 2;

[0049] The well edge 2 is an annular structure, and both the inner and outer walls are provided with an annular load-bearing platform, and the inner wall below the load-bearing platform is provided with an internal thread connected to the lower well wall;

[0050] The locking mechanism includes a locking rod capable of locking the manhole cover 1 and the manhole edge 2 by horizontal movement or rotation, and a driving mechanism for driving the locking rod to move;

[0051] The contact locking surface between the locking rod and the manhole cover 1 or the manhole edge 2 is a wedge-shaped surface.

[0052] See Figure 2 and Figure 3The locking rod includes a swing arm 5 and a plug arm 4. The center position of the swing arm 5 and the center position of the manhole cover 1 are rotatably installed along the vertical axis. The plug arm 4 is hinged at both ends of the swing arm 5. A guide wheel 6 is rotatably provided at the edge position of the bottom wall of the manhole cover 1. The guide wheel 6 is an I-shaped wheel. The free end of the plug arm 4 passes through the middle of the two sets of guide wheels 6.

[0053] When the driving mechanism drives any set of swing arms 5 or plug-in arms 4 in the locking rod, the plug-in arms 4 can be driven to feed along their own length direction and extend to the outside of the manhole cover 1 to contact the bottom wall of the bearing platform of the manhole edge 2;

[0054] See Figure 2 , a rack is provided on the side of one group of splicing arms 4, and one group of guide wheels 6 is used as the operating wheel 3, which is meshed with the rack, and the gear part of the operating wheel 3 is provided with the small diameter part of the I-wheel, that is, the upper and lower end surfaces of the I-wheel can limit the vertical movement of the splicing arm 4; when the operating wheel 3 rotates, the gear is meshed with the rack, driving the splicing arm 4 to feed axially, and driving the swing arm 5 to swing, and driving the splicing arm 4 at the other end to feed axially, thereby realizing the combination of the splicing arm 4 and the lower wall of the bearing platform along the well 2;

[0055] The contact surface between the free end of the plug-in arm 4 and the bottom wall of the load-bearing platform is a wedge-shaped surface;

[0056] At the same time, the contact surface between the free end of the plug-in arm 4 and the lower wall of the load-bearing platform is a wedge-shaped structure. As the insertion amount of the plug-in arm 4 increases, the relative displacement of the two in the vertical direction increases, which increases the pressure between the manhole cover 1 and the load-bearing platform of the manhole edge 2. When the surface of the manhole cover 1 is crushed or elastically vibrates, the probability of resonance of the manhole cover 1 is effectively reduced, thereby reducing vibration noise.

[0057] The locking rod adopts a three-link structure, in which the swing arm 5 is hinged in the middle position, and the free ends of the remaining plug-in arms 4 are limited by guide wheels 6, that is, the movement of one group of arms can drive the other two groups of arms to move synchronously, and the wedge-shaped surface contact between the plug-in arm 4 and the bottom wall of the load-bearing platform is utilized. As the insertion amount of the plug-in arm 4 increases, the vertical force between the plug-in arm 4 and the load-bearing platform becomes greater, which helps to eliminate the gap between the manhole cover 1 and the upper surface of the load-bearing platform, so that the manhole cover 1 fits tightly with the load-bearing platform, so that when the manhole cover 1 is crushed, no unnecessary vibration will be generated, thereby reducing noise. At the same time, the plug-in arm 4 is combined with the load-bearing platform to limit the upward movement of the manhole cover 1, thereby playing an anti-theft role.

[0058] The driving mechanism includes an operating wheel 3, which is coaxially fixed to one set of guide wheels 6, and a gear and rack that mesh with each other are provided between the operating wheel 3 and the plug-in arm 4 on the contact side;

[0059] Alternatively, the operating wheel 3 is coaxially and fixedly arranged with the middle axis of the swing arm 5 .

[0060] The operating wheel 3 is rotatably mounted on the manhole cover 1;

[0061] The operating wheel 3 passes through the manhole cover 1, and an operating hole adapted for an external operating tool is provided on the top of the operating wheel 3;

[0062] When the operating wheel 3 directly passes through the manhole cover 1, it helps to reduce the complexity of the structure of the manhole cover 1, is beneficial to production and cost reduction, and is easy to operate. However, the top of the operating wheel 3 is easily worn, and there are sealing problems in the side gaps.

[0063] Or the operating wheel 3 does not penetrate the manhole cover 1, and a magnet is provided inside the operating wheel 3; when there is a rotating external magnet above the manhole cover 1, it can drive the operating wheel 3 to rotate;

[0064] The use of built-in magnets can effectively solve the wear problem of the exposed position of the operating wheel 3 and the sealing problem of the surrounding gaps. It is suitable for working conditions such as communication wells and water meter wells, and helps to prevent surface water from seeping into the well.

[0065] See Figure 3 , a limit column 10 is provided at the bottom of the manhole cover 1 for limiting the swing angle of the swing arm 5. When the plug-in arm 4 moves along the axis to be plugged into the bearing platform of the well edge 2, the swing arm 5 conflicts with the limit column 10;

[0066] At the same time, it also prevents the plug arm 4 from being excessively deformed due to excessive feeding, which may cause a decrease in durability. By setting the limit column 10, the axial feeding amount thereof is limited.

[0067] Example 2:

[0068] See Figure 4-Figure 8 A double-layer load-bearing platform is provided on the inner wall of the well edge 2, and a gear ring is provided in the middle of the double-layer load-bearing platform for rotation; the locking rod includes several groups of arc-shaped rods 7, one end of the arc-shaped rod 7 is rotatably mounted with the well edge 2 along the vertical axis, and a gear meshing with the gear ring is fixed coaxially at the rotating shaft;

[0069] The free ends of one group of arc-shaped rods 7 are provided with lockers, and the free ends of the remaining arc-shaped rods 7 are provided with locking hooks; when the free ends of the arc-shaped rods 7 are all rotated to the center position of the well edge 2, the locking hooks can be locked with the lockers;

[0070] The edge of the manhole cover 1 is provided with a downward flange, and the inner wall of the flange is provided with an annular groove or a plurality of groups of penetrating locking holes. A locking cam 703 is coaxially fixed at the rotating shaft of the arc-shaped rod 7;

[0071] When the free end of the arc-shaped rod 7 rotates to the center position of the well edge 2, the long diameter end of the locking cam 703 can be inserted into the annular groove body or the locking hole of the well cover 1;

[0072] When the free end of the arc-shaped rod 7 rotates to the edge of the well 2, the locking cam 703 disengages from the annular groove or locking hole of the well cover 1;

[0073] The contact surface between the lower end surface of the cam 703 and the annular groove body of the manhole cover 1 or the bottom wall of the locking hole is a wedge-shaped surface;

[0074] Through the integrated design of the arc rod 7 and the locking cam 703, while the manhole cover 1 is locked, the arc rod 7 is used to form an anti-fall net under the manhole cover, and the locking mechanism is integrated into the well edge 2, which reduces the structure of the manhole cover 1 and reduces the cost of the manhole cover 1. When the manhole cover 1 is a wearing part, the cost can be reduced, and the locking mechanism and the anti-fall net are separated from the manhole cover 1. Even if the manhole cover is damaged, it will not affect the use of the anti-fall net.

[0075] The gear ring 9 and the gear in the arc rod 7 have a large transmission ratio. Even when the manhole cover 1 is disturbed by external vibration, the locking cam 703 is restricted by the gear ring 9 when the vibration is transmitted and will not rotate, thereby ensuring the stable locking of the manhole cover 1.

[0076] See Figure 8 A sealed chamber is provided on the outer side of the well 2, and a driving mechanism is arranged in the sealed chamber. The driving mechanism is a magnetic transmission mechanism 8, which includes a driving wheel 801 and a transmission wheel 802 that rotate along a vertical axis and mesh with each other. The transmission wheel 802 meshes with the ring gear 9. A permanent magnet is provided on the top of the driving wheel 801. When the external permanent magnet above the sealed chamber rotates, it can drive the driving wheel 801 to rotate;

[0077] The design of the magnetic transmission mechanism 8 leaves no gap between the well edge 2 and the manhole cover 1, thus preventing corrosion of the transmission mechanism by surface water and helping to extend the service life of the locking mechanism.

[0078] At the same time, by changing the transmission ratio of the driving wheel 801 and the transmission wheel 802, the actual input torque required to drive the arc rod 7 can be changed, which facilitates the design of the magnetic transmission. Even if the magnetic force in the driving wheel 801 decreases after long-term use, it can still meet the requirements of use.

[0079] The sealed chamber is open at the top, and a sealing plate is provided at the opening to facilitate maintenance of the driving wheel 801. When the magnetic transmission mechanism 8 fails, maintenance can be carried out, thereby improving the convenience of maintenance.

[0080] At the same time, when selecting materials for the manhole cover 1 and the manhole edge 2, a combination of PVC and glass fiber can be used for die-casting. Compared with traditional ductile iron manhole covers, this has the characteristics of high sealing, corrosion resistance and light weight, and is more suitable for use in scenarios with high sealing requirements such as water meter wells and communication wells.

[0081] At the same time, compared with traditional ductile iron manhole covers, manhole covers made of a mixed die-cast material of PVC and glass fiber have a non-shielding effect on signals and are more suitable for installing terminal communication devices in the well to form a local Internet of Things and monitor the equipment in the well.

[0082] See Figure 7 The arc-shaped rod 7 includes a set of main swing arms 701 and several sets of slave swing arms 702. The locker is fixedly installed at the free end of the main swing arm 701. The locker has a circular structure, and the circumferential surface is arranged with several sets of locking grooves in a ring array. When the free ends of the arc-shaped rod 7 are rotated to the center position of the well edge 2, the locking hooks of the slave swing arms 702 are all engaged in the locking grooves.

[0083] When the arc rod 7 rotates toward the center, the center positions of several groups of arc rods 7 can interact with each other to avoid the problem of a single arc rod 7 bending under load, thereby playing the role of an anti-fall net, that is, when a heavy object falls from the top, it can receive or cushion the heavy object to prevent the heavy object from falling directly into the well; at the same time, when the locking cam 703 is unlocked from the manhole cover 1, the arc rod 7 can rotate in the opposite direction with the locking cam 703, the middle locker disengages, and the arc rod 7 returns to the inner wall position of the well edge 2, without affecting the passability of the wellhead.

[0084] When the manhole cover 1 is damaged, if a person falls in, he or she will first touch one or more groups of arc rods 7. Since the rotating ends of the arc rods 7 are fixed, their free ends are restricted to each other, so they will not be able to block the person. At the same time, when the arc rods 7 are pressed down by heavy objects, their own curvature is enlarged, absorbing part of the kinetic energy, performing shock absorption, and reducing the degree of personal injury.

[0085] See Figure 5 , protrusions and grooves for preventing mistakes are provided between the circumferential surface of the manhole cover 1 and the inner wall of the manhole edge 2, and indicator marks for indicating the assembly direction are provided on the upper surfaces of the manhole cover 1 and the manhole edge 2.

[0086] When designing the arc rod 7, the curvature of the arc rod 7 is consistent with the inner curvature of the well edge 2, so that when the manhole cover 1 is opened, the arc rod 7 can be completely hidden between the double-layer load-bearing platform, thereby preventing people or objects passing through the well edge 2 from causing damage to the arc rod 7. In addition, the straight length of the two end points of the arc rod 7 should be greater than half of the inner diameter of the well edge 2. At the same time, the actual length of the arc rod 7 should be less than the spacing between the circumference of the inner wall of the well edge 2 between the two groups of arc rods 7 rotating shafts. If 4 groups of arc rods 7 are set, the length of the arc rod 7 should be less than 1 / 4 of the inner diameter of the well edge 2.

[0087] At the same time, in order to ensure the sealing performance of the manhole cover 1, two groups of sunken but non-through gripping holes 101 are symmetrically arranged on the surface of the manhole cover 1. The gripping holes 101 are sunken and horizontally sunken.

[0088] The gear ring 9 is an inner gear ring, which is rotatably installed at the gap position of the load-bearing platform, and a through hole connected to the sealing chamber is provided on the side of the gap position of the load-bearing platform. External teeth are provided on the outside of the gear ring 9 at this position, and the external teeth here are engaged with the transmission wheel 802.

[0089] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A theft-proof manhole cover, comprising a manhole cover (1), a manhole edge (2) and a locking mechanism, characterized in that: The manhole cover (1) is embedded in the middle of the manhole edge (2), and a sealing ring is provided between the vertical contact surface with the manhole edge (2); The well edge (2) is an annular structure, and both the inner and outer walls are provided with an annular load-bearing platform, and the inner wall below the load-bearing platform is provided with an internal thread connected to the lower well wall; A locking mechanism comprising a locking rod capable of locking the manhole cover (1) and the manhole edge (2) by horizontal movement or rotation, and a driving mechanism for driving the locking rod to move; The contact locking surface between the locking rod and the manhole cover (1) or the manhole edge (2) is a wedge-shaped surface; The inner wall of the well edge (2) is provided with a double-layer load-bearing platform, and a gear ring (9) is rotatably provided in the middle of the double-layer load-bearing platform; the locking rod comprises a plurality of groups of arc-shaped rods (7), one end of each arc-shaped rod (7) is rotatably mounted with the well edge (2) along a vertical axis, and a gear meshing with the gear ring is coaxially fixedly provided at the rotating shaft; The free ends of one group of arc-shaped rods (7) are provided with lockers, and the free ends of the remaining arc-shaped rods (7) are provided with locking hooks; when the free ends of the arc-shaped rods (7) are all rotated to the center position of the well edge (2), the locking hooks can be locked with the lockers; The edge of the manhole cover (1) is provided with a downward flange, and the inner wall of the flange is provided with an annular groove or a plurality of groups of penetrating locking holes, and a locking cam (703) is coaxially fixedly provided at the rotating shaft of the arc-shaped rod (7); When the free end of the arc-shaped rod (7) rotates to the center position of the well edge (2), the long diameter end of the locking cam (703) can be inserted into the annular groove body or the locking hole of the well cover (1); When the free end of the arc-shaped rod (7) rotates to the edge of the well edge (2), the locking cam (703) disengages from the annular groove body or the locking hole of the well cover (1); The contact surface between the lower end surface of the cam (703) and the annular groove body or the bottom wall of the locking hole of the manhole cover (1) is a wedge-shaped surface; a sealing chamber is provided on the outer side of the manhole edge (2), and the driving mechanism is arranged in the sealing chamber. The driving mechanism is a magnetic transmission mechanism (8), and the magnetic transmission mechanism (8) includes a driving wheel (801) and a transmission wheel (802) that rotate along a vertical axis and mesh with each other, and the transmission wheel (802) meshes with the ring gear (9). A permanent magnet is provided on the top of the driving wheel (801), and when the external permanent magnet above the sealing chamber rotates, it can drive the driving wheel (801) to rotate; The arc rod (7) comprises a group of main swing arms (701) and a plurality of groups of slave swing arms (702); the locker is fixedly mounted on the free end of the main swing arm (701); the locker is a circular structure, and a plurality of groups of locking grooves are arranged in a circular array on the circumferential surface; when the free ends of the arc rod (7) are rotated to the center position of the well edge (2), the locking hooks of the slave swing arms (702) are all engaged in the locking grooves; a protrusion and a groove for preventing theft are provided between the circumferential surface of the well cover (1) and the inner wall of the well edge (2); and an indicator mark for indicating the assembly direction is provided on the upper surfaces of the well cover (1) and the well edge (2).

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