JP2000045312A - Cover for underground structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To consequently increase friction by making a protrusion protruding from the plate face of a cover body a conic body whose lower part is large and upper part is small, making a truncated pyramid having the planar shape of a projection polygon, and providing a recess groove on the side of the protrusion. SOLUTION: A conic shape whose lower part is large and upper part is small is made, and a plurality of truncated pyramid-shaped protrusions 13 of a triangular pyramid, a rectangular pyramid or the like having a projection polygonal planar shape are provided on the plate face 12 of the cover body 11 of a manhole iron cover or the like. Recess grooves 17 are provided on the inclined inside 15 of each protrusion 13. In addition, projections may be provided on the inclined inside 15 of each protrusion 13. As a result, the corner and the like of the recess groove 17 or the projection and the truncated pyramid- shaped protrusion 13 effectively increase friction between a tire and a shoe bottom, and friction effect is maintained for a long time without reduction due to the development of the wear of the protrusion 13.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of projections projecting from a plate surface of a lid body as an uneven structure for increasing friction between a tire or a shoe sole or the like passing over an upper surface and preventing slip. And a lid for an underground structure having a space between the projections.

[0002]

2. Description of the Related Art A variety of patterns are formed on lids for various underground structures such as manhole lids.
This type of pattern is designed with the intent that the lid surface friction is not significantly different from that of the surrounding road surface and that the friction does not change drastically with the progress of the lid surface wear. However, in reality, it does not match the intended intention, and the concave-convex structure constituting the pattern will not be effective if the concave portion is filled with earth and sand.

For example, the invention of Japanese Patent No. 2758589 and its divisional application, Japanese Patent Application Laid-Open No. 10-131224, deal with the problem of drainage of rainwater, earth and sand, etc. flowing into the lid surface. From the center to the outer periphery. However, a manhole cover having a curved surface whose central portion is higher than its outer periphery is extremely well-known, and the concave portion on the cover surface is deeper at the outer periphery than at the central portion. That is, the difference from the conventionally known one is not always clear.

[0004] In the above-mentioned invention, the latter has a configuration in which a discharge groove which is opened on the outer periphery is provided on the upper surface of a convex portion provided in a concave portion on the lid surface. However, providing the discharge groove on the upper surface of the projection means that the effect of the discharge groove can be expected only for a certain limited time.
This is because as the abrasion of the upper surface progresses, the discharge groove is worn out and disappears.

[0005] In the latter case of the invention, when a two-stage structure is provided, the effective period of the protrusion is further limited and slightly reduced. Further, when the recess is provided in a shallow concave portion at the center similarly to the former, a situation may be considered in which the wear at the center is more advanced than at the periphery and the friction is uneven.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and its object is to effectively increase friction between a tire, a shoe sole, and the like, and to reduce the friction effect. The point is that it is maintained for a long time.

Another object of the present invention is to provide a lid for an underground structure in which a different pattern from the initial one appears on the upper surface when the height of the projection is reduced due to the progress of wear of the projection.

[0008]

In the present invention for solving the above-mentioned problems, the projection provided on the underground structure lid as an uneven structure has a conical shape having a large lower part and a small upper part, and a convex polygonal plane. It has a truncated pyramid shape as a basic shape, and has a groove on the inclined side surface of each projection.

The projections may be provided on the inclined side surfaces of the projections.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Underground structure lid 10 according to the present invention.
Has a concavo-convex structure for increasing friction between the tire or the sole of the shoe or the like passing over the upper surface and preventing slip.
This uneven structure is composed of a number of projections 13 protruding from the plate surface 12 of the lid main body 11 and a space 14 between each projection. See FIG. 5, FIG. 6, etc.

The cover body 11 is assumed to be a manhole iron cover or the like. Therefore, it is a cast product made of ductile cast iron or the like, and the uneven structure is also formed by casting. In the case of a circular manhole iron cover, the cover main body 11 may have a flat plate surface, or may have a curved plate surface as described above.

The projection 13 has a conical shape with a large lower part and a small upper part. Due to the conical three-dimensional shape, the protrusion 13 has the inclined side surface 15.
This inclination is equal to or greater than the inclination required for demolding during casting. Therefore, it is not necessary in the present invention to give a particular inclination for demolding.

The projection 13 in the present invention projects from the plate surface 12 of the lid body 11. In addition, the projections for preventing slip are not multi-stage structures but have a necessary and sufficient height of a so-called single-stage structure. The projection 13 has, as a basic shape, a convex polygon, that is, a truncated pyramid shape having a normal polygonal planar shape. The convex polygon is, for example, a polygon of a triangle, a quadrangle, a pentagon, a hexagon, or a heptagon or more, which appears on the upper surface 16. Such basic shapes are respectively triangular truncated pyramids, quadrangular truncated pyramids or more polygonal truncated pyramids.

A concave groove 17 is provided on the inclined side surface 15 of the projection 13 having the basic shape of the truncated polygonal pyramid. Groove 17
Is provided in the area of the side surface 15 and has a frontal shape such as a triangle (inverted V-shape) to an inverted U-shape.

A projection 18 may be provided on the inclined side surface 15 of the projection 13 having a basic shape of a truncated polygonal pyramid. Ridge 1
8 is also provided in the range of the side surface 15, and a shape having an angle such as a pyramid is more suitable.

FIGS. 1A, 1B and 1C show concave grooves 17.
FIG. 1A shows an example of a truncated triangular pyramid, and FIGS. 1B and 1C show an example of a projection 13 of a quadrangular pyramid. In FIG. 1C, the direction is different from that of FIG. 1B by 90 degrees, the inclination of the side surface 15 is steeper, and the bottom area is correspondingly smaller. Each has a front triangular groove 17, the top of which reaches the upper surface 16.

FIG. 2 shows an example of the projection 13 having the ridge 18. The ridge 18 has a triangular pyramid shape, and its vertex ends at the projection upper surface 16. The ridge 18 is formed of a triangular pyramid having a front triangular shape as in each example of FIG.

FIGS. 3 (a), 3 (b), 3 (c) and 4 show the plan shapes of the projections 13 of FIGS. 1 (a), 1 (b) and 3 (c) and FIG. Have been. Thus, the change in the form of the protrusion 13 before and after use can be grasped.
3 (a), (b), (c) and FIG. 4 show the state before use, and the right column shows a state in which the wear of the upper surface 16 has progressed.

As compared with the left and right sides, the height of the protrusion 13 is reduced, but the area of the upper surface 16 is increased, and the concave groove 17 and the ridge 1 are formed.
It can be seen that the effect of 8 extends to the upper surface 16 and changes its shape from a convex polygon to a concave polygon. As a result, in the present invention, friction due to the concave polygon is newly expected, and the feature is obtained that the friction does not decrease even when the projection 13 is worn. Reference numeral 16 'denotes a worn upper surface.

As described above, the projection 13 has the concave groove 17 or the ridge 18
Although the example in which the groove is provided has been described, the groove 17 and the ridge 18 may be mixed in one lid. In that case, the groove 17
The projection 13 provided only with the projection 13 and the projection 13 provided only with the ridge 18
May be mixed, or a concave groove 17 may be provided on one side surface 15 of one projection 13 and a ridge 18 may be provided on the other side surface 15.

The projections 13 fill the plate surface 12 of the lid body 11 with a pattern effective for entry from all directions as shown in FIG. 5 (FIG. 7), and the tire T passing over the upper surface. The underground structure lid is provided with a concave-convex structure for increasing friction between the underground structure and a shoe sole and preventing slip. Since the projection 13 has a truncated pyramid shape, the corner based on the ridge 19, the concave groove 17 or the ridge 18 increases the friction of the tire.

In particular, in a two-wheeled vehicle, the tire T inclines when traveling on a curve (FIG. 6). At this time, the portion of the tire T extending from the tread center portion to the sidewall is in contact with the lid, and the centrifugal force acts on the uneven structure simultaneously with the vertical load. Since the protrusion 13 in the present invention has a truncated pyramid shape, the tire T running on a curve is formed on the concave groove 17, the ridge 18, the ridge 19 and the like.
Gives the frictional resistance to bite, thereby enhancing the grip effect of the tire and preventing slip. Moreover, this effect is not reduced by the wear of the projection 13 as described above.

[0023]

Since the present invention is constructed and operates as described above, the single-stage structure itself gives a sufficient height to the projection, and the groove or the ridge formed on the inclined side surface has: The ridges and the like of the truncated pyramid-shaped projection effectively increase the friction between the tire and the sole of the shoe and the like, and the effect of the friction is not reduced by the progress of the wear of the projection and is maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a perspective view and a sectional view showing three types of projections having concave grooves (a), (b), and (c), which relate to an embodiment of a lid for an underground structure according to the present invention.

FIG. 2 is a cross-sectional view showing a projection having a ridge.

FIG. 3 is a plan view corresponding to FIG. 1, showing three (a), (b), and (c) three types of protrusions, showing a state in which abrasion has progressed before and after use.

FIG. 4 is a plan view related to the projection corresponding to FIG. 2, showing a state in which abrasion has progressed before and after use.

FIG. 5 is a plan view showing an example of a concavo-convex structure combining several types of protrusions.

FIG. 6 is an explanatory sectional view showing a relationship between a lid for an underground structure and a tire according to the present invention.

FIG. 7 is a partial plan view of a lid for an underground structure having an uneven structure according to the present invention.

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[Procedure amendment]

[Submission Date] July 16, 1999 (1999.7.1)
6)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Drawing

[Correction target item name] Figure 2

[Correction method] Change

[Correction contents]

FIG. 2

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroshi Shimada 2-19 Nakamachi, Kawaguchi-shi, Saitama Nagashima Casting Co., Ltd. (72) Inventor Yasuhiro Kubota 1-111-53 Tomimotomachi, Nara-shi, Nara F-term ( Reference) 2D047 BB23

Claims (4)

[Claims] 1. A large number of projections projecting from a plate surface of a lid main body, and a space between each projection to increase friction between a tire or a shoe sole or the like passing over an upper surface and prevent slippage. A lid for an underground structure having a concave-convex structure consisting of: a projection having a truncated pyramid shape having a large pyramid shape having a large lower portion and a small upper portion, and having a convex polygonal planar shape;
A cover for an underground structure having a concave groove on an inclined side surface of each projection. 2. A large number of projections projecting from a plate surface of a lid main body and a space between each projection to increase friction between a tire or a sole and the like passing over the upper surface and prevent slipping. A lid for an underground structure having a concave-convex structure consisting of: a projection having a truncated pyramid shape having a large pyramid shape having a large lower portion and a small upper portion, and having a convex polygonal planar shape,
A cover for an underground structure, wherein each of the projections has a ridge on an inclined side surface. 3. The underground structure cover according to claim 1, wherein the projection changes a planar shape of the projection upper surface from a convex polygon to a concave polygon by wear. 4. The lid for an underground structure according to claim 1, which has a large number of projections in which a concave groove and a convex stripe are mixed.