Manhole cover structure

A regular polygonal design for manhole covers and frames prevents rotation and bouncing, addressing safety hazards and installation issues by ensuring snug fitting and alignment.

JP2026006866AInactive Publication Date: 2026-01-16木下 智生 +1
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Patent Information

Application Number
JP2024106194
Authority / Receiving Office
JP · JP
Patent Type
Applications
Current Assignee / Owner
Filing Date
2024-07-01
Publication Date
2026-01-16
Estimated Expiration
Not applicable · inactive patent

AI Technical Summary

Technical Problem

Existing manhole covers can rotate and bounce due to vehicle contact, posing safety hazards, and previous anti-rotation solutions require precise alignment or cumbersome elastic material fitting, leading to loose fits and rattling.

Method used

The manhole cover and support frame are designed as regular polygons with matching shapes, ensuring snug fitting and preventing rotation by aligning corner portions to prevent relative movement.

Benefits of technology

The solution effectively prevents manhole cover rotation and bouncing, ensuring safe vehicle travel and smooth installation by eliminating relative rotation and misalignment.

✦ Generated by Eureka AI based on patent content.

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Abstract

To prevent the rotation of a manhole cover accompanying the start or the like of a traveling vehicle, to enable safe traveling and to maintain a stable closed state in various manholes, for example, for water supply and sewerage and an electric path installed on a road surface or the like.SOLUTION: In the manhole cover mounted to the opening section of the manhole M, the external shape of a manhole cover body 1 fitted to a bearing frame section 11 formed to the opening section of the manhole M is constituted in the same regular polygonal shape of a pentagon or more in a plane together with the internal shape of the bearing frame section 11. The manhole cover body 1 and the support frame part 11 are constituted, for example, as either an odd-numbered regular polygonal shape or an even-numbered regular polygonal shape in a plane. The plane shape of a support frame section 11 formed to an opening section in the manhole M corresponds to the external shape of the manhole cover body 1, and the corner section 2 of the manhole cover body 1 is closely fitted to the fitting corner section 12 in the support frame section 11.SELECTED DRAWING: Figure 1
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Description

[Technical Field]

[0001] The present invention relates to a manhole cover structure that prevents rotation of the manhole cover due to the start of a traveling vehicle or other events, allowing safe travel, and maintaining a stable closed state, for various manholes installed on road surfaces and other surfaces, such as in water supply and sewerage pipes and electrical wiring pipes. [Background technology]

[0002] Conventionally, when piping for water supply and sewerage or electrical lines is buried, manholes are constructed and arranged for inspection and other purposes, and the opening is closed by a manhole cover that can be opened and closed. The manhole cover is placed in close contact with a support frame formed on the top of the manhole frame so that there is no difference in level with the road surface and there is no rattle.

[0003] Furthermore, manhole covers themselves are adorned with various designs, which are achieved by forming irregularities on the top surface of the manhole cover, and most of these are flat and circular. Because of their circular shape, coupled with the irregularities on the surface, the manhole cover can rotate when coming into contact with the tires of a moving vehicle, and in some cases, can even bounce up and come off.

[0004] In light of these points, proposed configurations for preventing the rotation of manhole covers include the manhole cover frame structure disclosed in Patent Document 1, the cover receiving frame for a surface-buried frame disclosed in Patent Document 2, the manhole disclosed in Patent Document 3, and the feedwater heater manhole cover removal / installation device disclosed in Patent Document 4.

[0005] Patent documents 1 and 2 attempt to prevent the manhole cover from rotating by using a recessed and protruding fitting / engagement structure between the manhole cover and the support frame that supports it, Patent document 3 attempts to prevent the manhole cover from rotating by making the manhole cover and its support frame elliptical in shape, and Patent document 4 attempts to prevent the manhole cover from rotating by interposing an elastic material between the manhole cover and the support frame. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2022-95143 [Patent Document 2] Japanese Utility Model Application Publication No. 61-29811 [Patent Document 3] Japanese Utility Model Application Publication No. 53-105470 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-136878 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when the anti-rotation configuration is based on fitting or engaging recesses and protrusions as in Patent Documents 1 and 2, these recesses and protrusions must be precisely aligned, and in the case of Patent Document 3, which uses an oval-shaped cover, there is a risk of the manhole cover itself falling if the short diameter is positioned on the long diameter.In the case of Patent Document 4, which uses friction of elastic material, it is necessary to provide support grooves on the opposing surfaces of the manhole cover and support frame, into which the elastic material is fitted, which is cumbersome.

[0008] Furthermore, if the manhole cover is circular, simply fitting it into the support frame can result in loose fitting and rattle if foreign objects such as trash get caught in it. To solve this problem, it is necessary to move the cover around until a position where rattle doesn't occur is found, and then install it in the correct position.

[0009] The present invention was created in light of the various circumstances that existed in the past as described above, and aims to provide a manhole cover structure in which the manhole cover itself is formed into a regular polygonal shape with at least 5 sides in plan view, so that when attached to the opening of the manhole, it will not rotate even when a vehicle is moving or starting, allowing for safe travel and preventing the cover from jumping up or causing other dangerous situations. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the present invention is characterized in that, in a manhole cover that is attached to the opening of a manhole M, the outer shape of the manhole cover body 1 that is fitted into a support frame portion 11 formed at the opening of the manhole M is configured in a plane with the same regular polygonal shape of pentagons or more as the inner shape of the support frame portion 11. The manhole cover body 1 and the support frame 11 can both be configured as an odd or even regular polygon when viewed in plan, and can also both be configured as a regular pentagon to regular dodecagon when viewed in plan. The support frame 11 formed at the opening of the manhole M has a planar shape that corresponds to the outer shape of the manhole cover body 1, and the corner portion 2 of the manhole cover body 1 can be configured to fit snugly into the mating corner portion 12 of the support frame 11.

[0011] In the manhole cover structure of the present invention configured as described above, the outer shape of the manhole cover body 1 and the inner shape of the support frame part 11 that supports the manhole cover body 1 are both the same regular polygonal shape, so that the manhole cover body 1 is fitted snugly into the support frame part 11, and the corner parts 2 and mating corner parts 12 abut against each other and fit together, preventing relative rotation between the manhole cover body 1 and the support frame part 11. The manhole cover body 1 and the support frame part 11 are both formed in a plane in the shape of an odd regular polygon, thereby reducing the diagonal length and minimum width, and minimizing the receiving portion of the manhole cover body 1 on the support frame part 11. The fitting of the corner part 2 and the fitting corner part 12 brings the contact surfaces into close contact with each other when they are rotated relative to each other in opposite directions, but does not cause any positional deviation and does not move or rotate the manhole cover body 1 relative to the support frame part 11. The outer shape of the manhole cover body 1, together with the inner shape of the support frame portion 11, is configured as a regular polygon in a plane, so that when aligning the manhole cover body 1 with the support frame portion 11, for example, the adjustment angle of its rotation direction is equidistant, making it easy to shift the position and smoothing the alignment. [Effects of the Invention]

[0012] Since the present invention is configured as described above, there is no room for relative rotation between the manhole cover body 1 and the support frame part 11, and for example, by being placed on the road surface, the manhole cover body 1 will not rotate or bounce up even when a traveling vehicle runs over it and starts or drives away.

[0013] This is because, in the present invention, the outer shape of the manhole cover body 1 that is fitted into the support frame portion 11 formed at the opening of the manhole M is configured in a plane with the same regular polygonal shape of pentagons or more as the inner shape of the support frame portion 11, so that the manhole cover body 1 does not rotate within the support frame portion 11, and vehicles can travel safely even when placed on the road surface.

[0014] Furthermore, since the manhole cover body 1 and the support frame part 11 that supports it are both regular polygonal in shape, the rotational direction can be adjusted at equal intervals when aligning the manhole cover body 1 with the support frame part 11, so that the position shifting and fitting work can be carried out smoothly and quickly.

[0015] The manhole cover body 1 and the support frame part 11 are both formed in a plane in the shape of an odd-numbered regular polygon, thereby reducing the diagonal length and minimum width, and when fitting the manhole cover body 1 into the support frame part 11, the manhole cover body 1 is tilted so that it comes off the support frame part 11 and does not fall into the support frame part 11, allowing the fitting work to be carried out safely.

[0016] The corner portion 2 of the manhole cover body 1 and the mating corner portion 12 of the support frame portion 11 are tightly fitted together, preventing misalignment and greatly helping to prevent rotation.

[0017] The reference numerals in the above sections of the Means for Solving the Problems and the Effects of the Invention are used to facilitate reference to the components shown in the drawings. The present invention is not limited to the structure, shape, etc. shown by the reference numerals in the drawings and the description. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an exploded perspective view showing an embodiment of the present invention; [Figure 2] FIG. [Figure 3] These are also cross-sectional views when the lid is in place, where (A) shows the case with a tapered surface structure and (B) shows the case with a stepped structure. [Figure 4] 10A and 10B are plan views of another embodiment, in which (A) is a regular hexagon and (B) is a regular octagon. DETAILED DESCRIPTION OF THE INVENTION

[0019] Below, one embodiment of the present invention will be described with reference to the drawings. The reference numeral 1 shown in the drawings is a manhole cover body that covers the opening of the constructed manhole M, and this manhole cover body 1 is formed in the shape of a regular polygon with at least 5 sides when viewed from above.

[0020] In the illustrated example, the manhole cover body 1 is formed in a regular pentagon. However, it may also be a regular hexagon as shown in FIG. 4(A) or an even-numbered regular polygon such as a regular octagon as shown in FIG. 4(B), or even an odd-numbered regular polygon such as a regular heptagon or regular nonagon. In any case, it is sufficient that the manhole cover body 1 has a regular polygonal shape with enough corners 2 to prevent rotation in a plane when attached to the opening of the manhole M to be constructed. However, it is not formed in a regular polygonal shape with so many corners 2 that it approximates a perfect circle, because approximating a perfect circle may cause rotation in a plane in some cases. More specifically, it may be formed in a shape from a regular pentagon to a regular dodecagon in a plane.

[0021] In addition, the manhole cover body 1 and the support frame 11 may both be flat and have the same odd regular polygonal shape such as a regular pentagon or regular heptagon, thereby reducing the diagonal length and minimum width, and minimizing the receiving portion of the manhole cover body 1, such as the tapered surface and support step portion of the support frame 11 described below.

[0022] On the other hand, the inner shape (inner dimensions) of the support frame portion 11 formed at the opening of the manhole M has a planar shape that corresponds to the outer shape (outer dimensions) of the manhole cover main body 1, and the corner portion 2 of the manhole cover main body 1 is designed to fit snugly into the mating corner portion 12 of the support frame portion 11.

[0023] Furthermore, the number of corner portions 2 and mating corner portions 12 may be an even or odd number and are not particularly limited. By making them regular polygons, when the manhole cover body 1 is fitted into and attached to the support frame portion 11 of the constructed manhole M, the adjustment angle of the rotation direction can be made at equal intervals, so that the appropriate position can be adjusted and set by shifting the fitting position, improving workability.

[0024] As shown in Figure 4(A), the manhole cover body 1 has a tapered periphery that narrows toward the bottom, and in the support frame portion 11 of the manhole M, it fits snugly into a tapered surface that gradually widens toward the upper opening edge of the support frame portion 11.

[0025] The support frame portion 11 of the manhole M may have the above-mentioned tapered surface structure or a stepped structure as shown in Figure 4(B) so that the manhole cover body 1 fits tightly and is supported, and the support configuration is not particularly limited.

[0026] The width of the inner edge of the lower end of the support frame portion 10 (including the mating corner portion 12) is smaller than the maximum length of the corner portion 2 located on the diagonal line of the manhole cover body 1, so that the tilted manhole cover body 1 is inserted into the manhole M and does not fall into the manhole M.

[0027] Manhole cover body 1 is provided with the keyhole, decorative designs, and other features that have traditionally been attached and provided, and is made of the same materials that have traditionally been used, such as cast iron or concrete, but is simply formed into a regular polygonal shape of at least one regular pentagon when viewed from above. It may also be equipped with a mechanism to prevent manhole M from floating up due to internal pressure, may be hinged so that it can swing open and closed freely, and in some cases may be bonded between manhole cover body 1 and support frame 11.

[0028] Next, an example of its use will be explained. When a manhole M is constructed in an underground conduit such as a waterway or electrical line, the inner shape of the support frame 11 at the opening is configured as a regular polygon so that it matches the outer shape of the manhole cover body 1 that closes the opening of the support frame 11. For example, it can be constructed as a regular pentagon as shown in the figure, or as a regular hexagon or octagon as shown in Figure 4. Naturally, these are constructed and prepared, for example as a set, to correspond to the shape of the opening to be closed, and are installed in a predetermined location that has been excavated.

[0029] Furthermore, during maintenance, the opening and closing will still be performed using the designated opening and closing equipment. [Explanation of symbols]

[0030] M...Manhole 1...Manhole cover body 2...Corner 11...Support frame part 12...Mating corner

Claims

1. A manhole cover structure in which the outer shape of the manhole cover body, which is fitted into a support frame formed at the manhole opening, is configured in a plane with the same regular polygonal shape of pentagons or more as the inner shape of the support frame.

2. 2. The manhole cover structure according to claim 1, wherein the manhole cover body and the support frame are both formed in a planar shape of an odd-numbered regular polygon or an even-numbered regular polygon.

3. 2. The manhole cover structure according to claim 1, wherein the manhole cover body and the support frame are both formed in a plane into any one of a regular pentagon and a regular dodecagon.

4. 4. A manhole cover structure according to any one of claims 1 to 3, wherein the support frame portion formed at the opening of the manhole has a planar shape that corresponds to the outer shape of the manhole cover body, and the corners of the manhole cover body are tightly fitted into the mating corners of the support frame portion.

Citation Information

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