JPH0246507Y2 - - Google Patents

Description

[Detailed description of the invention] <Industrial application field> The iron manhole cover of this invention is mainly installed on the ground surface like a sewer manhole, and is designed to improve operability when opening the lid. This invention relates to improvements to crowbar insertion holes.

<Prior Art> The crowbar insertion hole provided in this type of conventional manhole iron cover is usually only formed with a slight notch to allow the tip of the crowbar to be inserted. Insert the tip of the crowbar into the crowbar insertion hole, lift the iron lid slightly using the receiving frame as a fulcrum, insert the key for opening the lid into the key hole provided in the iron lid, and lift the lid. It was open. Since this is inconvenient, a crowbar insertion hole structure has been proposed in which the use of a key for opening the lid is omitted. The crowbar insertion hole is as shown in FIG. The crowbar is formed so that it can be pried open using the part as a fulcrum, and the other end of the crowbar is formed in a T-shape so that it can be inserted into the elongated hole 2. In this case, pry open the iron cover 1 with one end of the crowbar to loosen the fitted state, and then
The letter-shaped part 4 is inserted and rotated 90 degrees to engage the elongated hole, and the T-shaped part is pulled up to open the lid.

<Problems to be solved by the invention> Even with conventional manhole iron covers that can be opened relatively easily, it is difficult to loosen the fitting between the iron cover and the receiving frame with a crowbar, and then open the opposite side of the crowbar with a crowbar. There was a problem where I had to replace the insertion hole and open the lid.

<Means for solving the problem> The means of this invention consists of an upper wall portion forming the upper surface and an outer peripheral surface that is connected to the outer edge of the upper wall portion and fits into the inner periphery of the receiving frame forming the manhole. In the manhole iron cover, the manhole iron cover has a peripheral wall portion formed in the outer edge of the upper wall portion, and a notch portion for inserting a crowbar is formed across both the upper wall portion and the peripheral wall portion. A width corresponding to the diameter of the tip of the crowbar is formed from the vicinity to a predetermined height position in the middle of the peripheral wall, and the width is expanded to both sides from the predetermined height position until reaching the lower end of the peripheral wall. It is characterized in that the predetermined height position is defined below a lower surface of the outer edge of the upper wall portion.

<Operation> According to the means of this invention, the iron lid is opened as follows. First, the fitting between the receiving frame and the iron lid is loosened by inserting the tip of a crowbar into the notch and levering up the iron lid using the edge of the receiving frame as a fulcrum. In that case, the crowbar has small protrusions (for example, short cylindrical protrusions) protruding from both sides of the part slightly before the part inserted into the notch, and the distance between the two protruding ends is the width of the notch. Use one with dimensions that allow it to pass through. After loosening the fit between the receiving frame and the iron lid as described above, push up the iron lid using leverage so that the wide part is above the top of the receiving frame, and then insert the crowbar further. It goes through the wide part and enters the underside of the iron lid. Following this, when the pushing force of the iron cover is loosened, the iron cover will lower slightly, and the small protrusions of the crowbar will engage with both sides of the narrow part above the wide part of the notch. . Therefore, if the crowbar is pulled upward or diagonally upward in this state, the iron cover will be pulled up and the cover will be in an open state.

<Example> In FIGS. 1 to 4, 10 is an iron lid, 11 is a receiving frame, and 12 is a notch, and this example is designed for use in a sewer.

The iron lid 10 includes an upper wall portion 20 that forms a circular upper surface when the lid is closed, and a peripheral wall that is connected to the outer edge of the upper wall portion 20 and is slightly elongated to form a tapered outer peripheral surface that becomes smaller in diameter from the entire circumference downward. Although details are not shown, a peripheral wall portion 2 on the lower surface of the iron lid 10
A hinge portion 22 is provided that connects a proper location near 1 and a proper location of the receiving frame 11, which will be described later. The receiving frame 11 is a frame-like thing forming a manhole, and the iron cover 10
The inner circumferential surface 2 that fits into the tapered outer circumferential surface of the circumferential wall portion 21 of
3, and the fitted state is the closed state.

As shown in FIG.
It is provided on the outer edge of the iron lid 10 at a position opposite to position 2, and extends over the upper wall part 20 and the peripheral wall part 21. As shown in FIG. 2, the upper wall 20 has a planar shape with a predetermined width D ₁ and the inner part forms an arc, and the entire thickness is cut out. As can be seen, the upper part from the upper end to the lower end is formed to have the above-mentioned width dimension _D1 , and from a predetermined height position in the middle, it is formed into a wide part 12a having a predetermined width dimension _D2 that expands on both sides. Width dimension from D ₁ to D ₂
As seen in FIG. 1, the height position that changes to is below the lower surface 20a of the upper wall portion 20, thereby forming the engaging portions 24, 24.

In the figure, 25 is a hook, 26 is a hook engaging portion, and 27a, 27b, and 27c are side walls.
The hook 25 is pivotally supported on the iron lid 10, and the hook engaging portion 26 is provided to protrude from the receiving frame 11. These allow the iron lid 10 to float to a certain extent, but cannot exceed a predetermined size. The engagement between the two prevents displacement. Side walls 27a, 27
b, 27c, the odor comes from the sewage as much as possible in the notch 1.
This is a partition installed to prevent people from entering the outside world.

In order to open the iron manhole cover 10 from the closed state shown in FIG. 4, a crowbar 30, the tip of which is shown in FIGS. 1 and 5, is used. The crowbar 30 is a steel rod with a predetermined diameter d, and the tip is formed flat with a slightly smaller diameter.
This corresponds to the driven portion 25a of No. 5, and is not necessary if such a hook 25 is not provided. What is necessary is a short cylindrical small protrusion 31 protruding from both sides of the portion with a diameter d. , 31. The diameter d is slightly smaller than the width _D1 , and the dimension between the tips of the small protrusions 31, 31 is slightly smaller than the width _D2 .

The lid opening operation is performed as follows. First, the tip of the crowbar 30 is inserted into the notch 12 shown in FIG. 4, and the iron cover 10 is pried up using the receiving frame 11 as a fulcrum to loosen the tapered fitting state. Next, when the crowbar 30 is inserted at an angle as shown in FIG.
It comes off from the bottom of 6. Push up the iron lid 10 again using the lever action and further insert the crowbar 30 so that the small protrusions 31, 31 pass through the wide part 12a of the notch 12, the state shown in FIG. 6 will be obtained, so relax the force on the crowbar 30. When the iron lid 10 is lowered slightly, the small protrusions 31, 31 come to engage with the engaging portions 24, 24, as shown in FIG. In this state, pull up the iron lid 10 with the crowbar 30, and then continue to
It is brought into the open state by inverting or horizontally turning around 2.

In this lid opening operation, the reason for inserting the crowbar 30 through the wide part 12a so that the small protrusions 31, 31 pass through is to insert the crowbar 30 easily without pushing the iron lid 10 upwards too much. 12a
is provided.

In this embodiment, the crowbar also functions as a key, and this type of iron lid with a hook has the advantage of not requiring a separate key to remove the hook.

<Effects of the invention> According to this invention, the lid can be opened by inserting the crowbar into the notch and then operating it without replacing it. Therefore, the opening operation of the manhole iron cover is greatly improved compared to the conventional method. Further, since the size of the opening of the notch on the top surface in the closed state corresponds to approximately the cross-sectional dimension of the crowbar, it may be relatively small.

[Brief explanation of the drawing]

Fig. 1 is a partial front view of one embodiment of this invention, Fig. 2 is a partial plan view corresponding to Fig. 1, Fig. 3 is a plan view showing the iron lid and its receiving frame of the same embodiment, and Fig. 4. is an enlarged cross-sectional view taken along the line A-A in Fig. 3, Figs. 5 to 8 are cross-sectional views of the same cross-section as Fig. 4, showing different states in the middle of opening the lid, and Fig. 9 shows the difference between the conventional crowbars for opening the lid. It is a schematic partial top view which shows an example of a hole and a crowbar. 10... Iron lid, 11... Receiving frame, 12... Notch, 12a... Wide part, 20... Upper wall part, 20a
... lower surface, 21 ... peripheral wall section, 24 ... engaging section, 3
0... Burl, 31... Small protrusion.

Claims (1)

[Scope of utility model registration request] It has an upper wall portion forming an upper surface, and a peripheral wall portion forming an outer peripheral surface that is connected to the outer edge of the upper wall portion and fits into the inner periphery of the receiving frame forming the manhole, and the upper wall portion and In a manhole iron cover in which a notch for inserting a crowbar is formed across both sides of the circumferential wall, the notch extends from near the outer edge of the upper wall to a predetermined height position in the middle of the circumferential wall. is formed to have a width corresponding to the diameter of the tip of the crowbar, and is formed into a wide portion extending from the predetermined height position to the lower end of the peripheral wall on both sides than the above-mentioned width,
An iron cover for a manhole, characterized in that the predetermined height position is set below a lower surface of the outer edge of the upper wall portion.