JP2971850B2 - Hook structure of manhole cover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manhole used for maintenance and inspection of a sewer or an underground cable, and more particularly to a hook hole structure of a lid for opening and closing the manhole.

[0002]

2. Description of the Related Art As a conventional technology, Japanese Utility Model Application Laid-Open No. 61-768 is proposed.
No. 46 was described. That is, as shown in FIGS. 4 and 5, a ring-shaped seat frame 1 is fixed to the opening edge of the manhole, and a disc-shaped lid 2 is detachably fitted to the seat frame 1. A hook hole 3 configured as follows is formed on the outer peripheral portion of the lid 2. That is, a hook-shaped groove 4 is formed in the outer peripheral portion of the lid 2 and is recessed downward and the outer end of which is open to the outer peripheral end surface 2 a of the lid 2. On the upper surface of one facing wall 4a of the concave groove 4, a long and columnar locking body 5 is formed so as to protrude toward the other facing wall 4b. The locking body 5 has a large-diameter flange 5a formed at a protruding end thereof, and a gap 6 for cleaning the recess 3 formed by separating the protruding end from the other facing wall 4b. When the lid 2 is opened, first, the operation rod 4 is moved sideways and reciprocated in the cleaning gap 16 to scrape the accumulated sand and dust from both ends of the hook hole 3 to the outside. Thereafter, as shown in FIG. 4, the lower end of the rod-shaped operation rod 7 is inserted into the concave groove 4 from the outer peripheral end side of the lid 2 to engage with the lower surface of the locking body 5, and the operation rod 7 is seated. The operation is performed by rotating the frame 1 leftward in FIG. In this case, the operation rod 7 is prevented from sliding in the protruding end direction from the locking body 5 by the flange 5a.

[0003]

In the above prior art, the locking member 5 is provided only on one body surface wall 4a of the concave groove 4 so that the operation rod 7 can be smoothly engaged. Thus, the amount of protrusion of the locking body 5 increases. For this reason, a large bending moment is generated at the base of the locking member 5 when the lid 2 is opened, and this portion is easily broken, and the durability of the hook hole 3 is reduced. In order to prevent this, there is a means for increasing the diameter of the locking body 5, but in this case,
The concave groove 4 also needs to be large, and the rigidity of the lid 2 decreases. Furthermore, it is difficult to scrape out the sand and dust accumulated in the concave groove 4, and the operating rod 7 cannot be engaged with the locking body 5, so that the lid cannot be opened. An object of the present invention is to provide a durable hookhole structure for a manhole cover by providing a pair of locking members facing each other on a concave facing wall so as to smoothly engage an operation rod. For the purpose .

[0004]

Means for Solving the Problems The present invention has the following configuration to achieve the above object. That is,
The invention according to claim 1 is a manhole cover in which a lid is detachably fitted to a seat frame provided at an opening edge of the manhole, wherein the outer periphery of the lid is recessed downward and the outer end of the lid is closed. A hook-shaped concave groove is formed on the outer peripheral end face, and a locking member having a short and columnar curved surface with a continuous lower surface is formed at the upper part of the facing wall of the concave groove and at the radial center of the lid. The projections are formed so as to face each other, and a gap is provided between the locking members that is smaller than the distance between the facing walls .

[0005]

According to the first aspect of the present invention having the above-described configuration, the amount of protrusion of each locking member from the opposed facing wall of the concave groove is reduced, and the bending rigidity is increased. In addition, each of the locking members is engaged with the operation rod for opening the lid fitted in the concave groove from both sides thereof, so that the load applied from the operation rod to the lid is stabilized. Further, when the sand or dust accumulated in the hook hole 3 is scraped out, the cleaning rod is quickly reciprocated in the cleaning gap 16 so that the sand or dust is removed from both ends of the hook hole 3 by the width of the gap 16. And facing wall 1
When the lower end portion of the operating rod 17 is inserted into the concave groove 14 from the outer peripheral end surface 12a side of the lid 12, since it is flipped out and scraped out over a wide width between 4a and 14a,
Even when the operating rod 14 is engaged with the lower surfaces of the locking members 15 and 15 without being hindered by sand or dust, the lid can be easily opened and closed because the accumulated sand and dust are scraped out .

[0006]

Embodiments of the present invention will be described below with reference to the drawings. In the drawings, FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention, FIG. 2 is a plan view of the essential part, and FIG. 3 is a side view of a hook hole.

In FIG. 1, reference numeral 10 denotes a manhole;
A ring-shaped seat frame 11 is fixed to the opening edge. The inner peripheral surface 11a of the opening of the seat frame 11 is tapered and expanded upward from below. The above seat frame 11
A disk-shaped lid 12 is detachably fitted to the inner peripheral surface 11a of the disk. This lid has its outer peripheral end face 12a
Is formed in a tapered shape corresponding to the inner peripheral surface 11a.

[0008] On the outer peripheral portion of the lid 12, a hook hole 13 configured as follows is formed. That is, on the outer periphery of the lid 12,
A hook-shaped groove 14 is formed which is recessed downward and whose outer end is opened on the outer peripheral end surface 12 a of the lid 12. Short and columnar locking members 15 are formed to protrude above the facing walls 14a of the concave groove 14 so as to face each other. Each of the locking members 15 is formed symmetrically, and its base 15a is formed by a large circular arc surface.
4a and 14a, and the protruding ends of the locking members 15 and 15 are separated from each other so that
Is formed. Here, in this example, the width L1 of the concave groove 14 is
Is 27 mm, the protrusion of the locking body 15 is 5 mm,
The amount L2 of the gap 16 is 7 mm.

Next, the mode of use of the above embodiment will be described. When the lid 12 is opened, it is scraped out using the cleaning gap 16. Prior to opening the lid, sand and dust accumulated in the hook holes 3 formed on the edge of the lid 12 are scraped. To do this, first, insert the tip of the cleaning rod, which is also
, And moved toward the center or radially through the cleaning gap 16.
By this operation, sand and dust are scraped out from both ends of the hook hole 3 to the outside by using not only the width of the gap 16 but also the wide width between the facing walls 14a. After cleaning the hook 3 in this manner, as shown in FIG. 1, the lower end of the rod-shaped operation rod 17 is inserted into the concave groove 14 from the outer peripheral end face 12a side of the lid 12, and the locking members 15 Of the operating rod 7
Is rotated left in FIG. 1 with the inner peripheral upper edge 11b of the seat frame 11 as a fulcrum.

[0010] Then, each of the locking members 15 is connected to the operating rod 1.
7, the lid 12 is rotated upward with respect to the seat frame 11, and the manhole 10 is opened. In this case, each locking body 15, 15 faces the facing wall 14 of the concave groove 14.
a and 14a, and their bases 15a and 15a have large arc surfaces to face the facing walls 14a and 14a.
a, the bending rigidity is increased. Further, each of the locking members 15 engages with the operation rod 17 fitted in the concave groove 14 from both sides thereof,
The load applied from the operating rod 17 to the lid 12 is stabilized, and the lid 12 is opened without being twisted against the seat frame 11.

[0011]

As is apparent from the above description, claim 1
In the invention according to the present invention, on the upper part of the facing wall of the concave groove formed in the outer peripheral portion of the lid, a short and columnar locking body having a continuous curved lower surface is formed so as to face each other and protrude, A gap is provided between the locking bodies, so that the operating rod does not catch on the lower surface of the locking body, sand and dust can be scraped out smoothly, and the operation rod can be smoothly engaged while maintaining durability. It is possible to obtain a hook hole of a manhole cover with a certain thickness. Although the hook hole is partially narrowed by the locking body, the ends that sandwich the locking body are wide, so that when the operating rod is reciprocated, sand and dust are quickly discharged from the wide opening. there is an effect of Runado.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part showing an embodiment of the present invention.

FIG. 2 is a plan view of a main part of the present invention.

FIG. 3 is a side view of the hook portion of the present invention.

FIG. 4 is a sectional view of a main part showing a conventional example.

FIG. 5 is a plan view of a main part of the present invention .

[Explanation of symbols]

 Reference Signs List 10 manhole 11 seat frame 11a inner peripheral surface 12 lid 12a outer peripheral end surface 13 hook hole 14 concave groove 14a facing wall 15 locking body 15a base 16 gap 17 operation rod

Claims (1)

(57) [Claims] 1. A cover for a manhole in which a lid is detachably fitted to a seat frame provided at an opening edge of a manhole, wherein the lid is recessed downward in an outer peripheral portion and an outer end thereof is formed on an outer peripheral end surface of the lid. A hook-shaped concave groove that opens is formed, and short and columnar locking members having a continuous curved lower surface are opposed to each other at the upper part of the facing wall facing the concave groove and at the radial center of the lid. A hook hole structure for a manhole cover, wherein a gap is provided between each of the locking members and smaller than the distance between the facing walls.