JPH09151474A - Manhole cover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily find the position of a manhole even at a dark place or the like. SOLUTION: A manhole cover 3 is formed to have a recess 5 on the upper surface thereof, with the axial center direction of the recess 5 taken at a suitable angle with the upper surface. Also, the bottom 5a of the recess 5 is fitted with a reflector 6 capable of emitting reflected light L2 , toward the aperture of the recess 5, upon receipt of irradiation light L1 . The irradiation light L1 , when emitted along the axial center direction of the recess 5, enters the internal space thereof, and the reflected light L2 of the light L1 returns to the position of a light source 7. Thus, the reflected light L2 can be arrested over a wide range, when a worker's eyes 8 or a detecting device is aligned with the position of the light source 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole cover provided on a manhole opened near the surface of the earth, such as a manhole for underground fire hydrants and other emergency manholes.

[0002]

2. Description of the Related Art Generally, when installing a manhole for underground fire hydrants and other emergency manholes, a street light, a display board and lighting therefor should be provided together in consideration of emergency work at night. There are many.

[0003]

However, there are manholes installed in a dark place and manholes that are not provided with street lights, etc., and if such a manhole requires emergency work, the installation position is Difficult to find.

The present invention solves the above problems, and an object of the present invention is to make it possible to easily find the installation position of a manhole even in a dark place or at night.

[0005]

In order to solve the above problems, the present invention relates to a manhole cover provided in a manhole opening near the surface of the earth, wherein the manhole cover has an upper surface and an axial direction with respect to the upper surface. Provided is a manhole cover in which a concave portion having an appropriate angle is formed, and a light emitting portion which emits fluorescence or reflected light in a direction toward an opening of the concave portion is provided at a bottom portion of the concave portion.

When searching for the position of the manhole opening near the surface of the earth, the worker often irradiates light while walking, and when the worker is away from the manhole, the manhole (that is, the manhole cover) is diagonally upward. Light is emitted from.

When the manhole cover having the above-mentioned structure is irradiated with light obliquely from above, when the light irradiation direction coincides with the axial direction of the recess, the light enters the recess and hits the light emitting portion at the bottom thereof. The fluorescence or reflected light emitted thereby travels in the same path as that of the irradiated light in the reverse direction, goes out of the opening of the concave portion, and returns to the position of the light source. Therefore, by aligning the operator's eyes or the detection device with the light source position, fluorescence or reflected light can be captured, and the manhole cover can be easily found. As the light emitting portion, for example, a retroreflector (surface) can be used.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2, a flat manhole cover 3 is provided on a manhole 2 that opens to a road 1. The manhole cover 3 has a notch 4 formed in a circumferential shape on the upper surface thereof, and a recess 5 is formed by embedding a small-diameter cylindrical body so as to open in the notch 4.

The recess 5 is arranged so that its axial direction coincides with the radial direction of the lid 3, and is inclined vertically so that the axial direction forms an appropriate angle with respect to the upper surface of the lid 3. The bottom 5a is provided with a reflector 6 in a direction orthogonal to the axial direction of the recess 5.

The surface 4a on the outer peripheral side of the notch 4 is inclined at substantially the same angle as the lower side surface of the recess 5, and the opening of the recess 5 belongs to the surface 4b on the inner peripheral side. The operation of the above configuration will be described.

In the vicinity of the manhole 2, the manhole 2
When light is radiated in various directions from the light source 7 diagonally above,
As shown in FIG. 2, the light irradiation direction and the manhole cover 3 are shown.
When the axial direction of the concave portion 5 provided in the concave portion 5 coincides with the axial direction of the concave portion 5, the irradiation light L ₁ enters the concave portion 5 and strikes the reflecting plate 6 provided on the bottom portion 5a, and the reflected light L ₂ is the irradiation light. The same path as L ₁ is followed in reverse to exit from the opening of the recess 5 and return to the position of the light source 7.

At this time, if the operator's eyes 8 are made to coincide with the position of the light source 7 as shown in the figure, or if a detection device is provided at the position of the light source 7, the reflected light L ₂ can be captured and is wide. The manhole cover 3 can be found in the range.
Since the position away from the path of the reflected light L ₂ reflected light L ₂ is not captured, a possibility that the reflected light L ₂ is captured in such a driver of the vehicle is little.

The notch 4 prevents water or foreign matter from entering without disturbing the entry and exit of light into and from the recess 5. In the above configuration, when fluorescent paint is applied to the bottom 5a of the recess 5 instead of providing the reflection plate 6, a part of the fluorescence emitted by the light hitting the fluorescent paint returns to the position of the light source 7.

FIG. 3 shows another embodiment of the manhole cover. The manhole cover 9 is different from the one described above in that the recess 10 is formed in a fan-shaped cross section. The bottom 10a of the recess 10 is provided with a reflection plate 11 in a direction orthogonal to the axial direction of the recess 10.
The outer peripheral surface 12a of the cutout 12 is formed so as to be inclined at substantially the same angle as the lower surface of the recess 10.

Also with this configuration, it is possible to capture reflected light or fluorescence at the position of the light source.

[0016]

As described above, according to the present invention, by irradiating light in various directions in the vicinity of the manhole, the radiated light is made to enter the inside of the concave portion provided on the upper surface of the manhole cover. The fluorescence or reflected light emitted thereby can be captured at the position of the light source. Therefore, in a fairly wide area near the manhole,
The manhole cover and manhole can be found relatively easily.

Although the light of the vehicle passing near the manhole may enter the recess, since the position of the light of the vehicle and the position of the eyes of the driver are usually apart from each other, the fluorescence or the reflection emitted from the recess may occur. Light is rarely seen by the driver,
It does not interfere with traffic.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an embodiment of a manhole cover of the present invention.

FIG. 2 is a schematic diagram illustrating the principle of finding the manhole cover shown in FIG. 1 by irradiating it with light.

FIG. 3 is an explanatory view showing another embodiment of the manhole cover of the present invention.

[Explanation of symbols]

1 Road 2 Manhole 3 Lid for manhole 5 Recess 5a Bottom of recess 6 Reflector L ₁ Irradiation light L ₂ Reflected light 9 Lid for manhole 10 Recess 10a Bottom of recess 11 Reflector

Claims (1)

[Claims] 1. A manhole cover provided on a manhole opening near the surface of the earth, wherein a recess is formed on the upper surface so that the axial center direction forms an appropriate angle with respect to the upper surface, and the bottom of the recess is externally exposed. A manhole cover, which is provided with a light emitting portion that emits fluorescent light or reflected light in a direction toward an opening of a concave portion when receiving incoming light.