Temporary lid for hole

Abstract

The present invention comprises: a circular lid body 10 larger than an opening H; a reinforcement frame 20 provided on a lower surface of the lid body 10 so as to be positioned in the opening H; and a slide part 30 that slidingly moves more toward a radial-direction outer peripheral side than toward the reinforcement frame 20. The slide part 30 is mounted onto a fastening bolt 31 inserted from an upper surface side of the lid body 10 through a long hole 11 formed in the lid body 10 so as to extend in a radial direction or a width direction thereof, and the slide part is thereby supported on a lower surface side of the lid body 10. Thus, the slide part 30 is slid and moved to abut on the inner surface of the opening H, thereby allowing the slide part 30 to be easily attached to holes of various sizes and shapes.

Description

Temporary hall cover

[0001] The present invention relates to a temporary hole cover used to temporarily cover openings such as manhole openings installed mainly at construction sites and sidewalks, and handholes installed in buildings, apartment buildings, etc.

[0002] Conventionally, manholes and handholes (underground boxes) have been closed with sturdy cast iron covers to prevent them from being easily opened by tampering or damaged by large vehicles passing through them. However, cast iron covers are heavy, making it difficult to open and close them every time workers enter and exit the manhole or handhole frequently, such as during inspections, cleaning work, or construction work. For this reason, temporary covers made of lightweight materials are often used instead of the heavy, sturdy cast iron covers until the work is completed.

[0003] For example, Patent Document 1 below proposes a temporary manhole cover made of a steel plate approximately 5 mm thick and having an insertion hole for inserting an air duct and a light entrance hole for admitting external light. Patent Document 2 below also proposes a temporary manhole cover made of glass-fiber reinforced plastic and having a ventilation duct hole, a cable introduction hole, and multiple light entrance holes. Patent Document 3 below also proposes a temporary manhole cover whose main body is made of a steel plate and further has multiple through-holes through which pins or other protrusions can be inserted, allowing it to be adapted to the size of the manhole opening at the construction site.

[0004] JP 2003-105789 A JP 2008-202359 A JP 2007-16510 A

[0005] The temporary manhole cover shown in Patent Document 3 mentioned above can be adapted to the size of the manhole opening relatively easily at the construction site by inserting a protrusion such as a pin into an appropriate through-hole. However, since a large number of through-holes must be formed in advance in the temporary cover body, there is a risk that large amounts of rainwater, mud, etc. will flow into the hole through these many through-holes.

[0006] Furthermore, when this temporary cover is applied to handholes (underground boxes) installed as a place for connecting or inspecting buried electric wires, cables, and electrical conduits, there is a risk that rainwater, mud, etc. will flow into the handhole (underground box) through the through-hole and accumulate in large quantities. Furthermore, since the size can only be adjusted between pre-formed through-holes, there is a risk of significant wobble if the size does not fit perfectly with the opening. Furthermore, if the through-hole is an elongated hole, as shown in Figure 5 of the same document, in order to secure a bolt at a desired position in the elongated hole, the bolt must be tightened while holding the nut on the back side with a spanner or wrench, making this adjustment process difficult.

[0007] Therefore, the present invention was devised to solve these problems, and its purpose is to provide a new temporary hole cover that can be easily attached to holes of various sizes and shapes.

[0008] In order to solve the above problems, the first invention is a temporary lid for a hole that is placed over an opening to close it, comprising: a circular or rectangular lid body that is larger than the opening; a reinforcing frame provided on the underside of the lid body so as to be positioned within the opening; and a sliding portion that slides radially outward or widthwise outward from the reinforcing frame to abut the inner surface of the opening, wherein the sliding portion is supported on the underside of the lid body by threading onto a fastening bolt that is inserted from the top side of the lid body through an elongated hole formed in the lid body so as to extend radially or widthwise.

[0009] With this configuration, the sliding part provided on the underside of the lid body together with the reinforcing frame can be slid radially outward or widthwise outward from the reinforcing frame to abut against the inner surface of the opening, making it easy to attach to holes of various sizes and shapes. Furthermore, after closing the opening with the lid body, the sliding part can be slid from the top side of the lid body to easily adjust its position.

[0010] The second invention is the temporary hall cover according to claim 1, characterized in that a plurality of recesses into which the heads of the fastening bolts fit are formed along the edge of the elongated hole. With this configuration, even if the fastening bolts loosen somewhat due to vibrations caused by passing cars, the heads of the fastening bolts fit into the recesses, so the fastening bolts will not shift out of position.

[0011] The third invention is the temporary hole lid of the first invention, characterized in that the reinforcing frame extends from approximately the center of the lid body in a cross or Y shape. With this configuration, by providing the sliding portion at the tip of each reinforcing frame, the sliding portion can abut against the inner surface of the opening at up to four or three points. This allows the lid body to fit stably into the hole.

[0012] The fourth invention is the temporary hole lid of the third invention, characterized in that the sliding portion is I-shaped or T-shaped and extends in the radial or width direction of the lid body. With this configuration, the sliding portion can abut against the inner surface of the opening at at least four points or three or more points. This allows the lid body to fit more stably into the hole.

[0013] The fifth invention is a temporary hall cover according to any one of the first to fourth inventions, characterized in that the cover body is made of checkered steel plate. With this configuration, it is possible to achieve a significant weight reduction compared to conventional cast iron covers while maintaining the required strength, and it is also possible to achieve a non-slip surface.

[0014] According to the temporary hole cover of the present invention, the sliding portion provided on the underside of the cover body together with the reinforcing frame can be slid radially outward or widthwise outward from the reinforcing frame to abut against the inner surface of the opening, making it easy to attach to holes of various sizes and shapes.

[0015] 8 is a plan view showing one embodiment of the temporary hole cover 100 according to the present invention. A cross-sectional view taken along line A-A in FIG. 1. A partially enlarged view showing the S portion in FIG. 1. A partially enlarged view showing the S portion in FIG. 2. A plan view showing an example in which the temporary hole cover 100 according to the present invention is applied to a small-diameter opening H1. A plan view showing an example in which the temporary hole cover 100 according to the present invention is applied to a large-diameter opening H2. A plan view showing an example in which the temporary hole cover 100 according to the present invention is applied to a rectangular opening H3. A plan view showing another embodiment of the temporary hole cover 100 according to the present invention. A partially enlarged view showing the S portion in FIG. 8. A plan view showing another embodiment of the temporary hole cover 100 according to the present invention. A plan view showing another embodiment of the temporary hole cover 100 according to the present invention. A plan view showing another embodiment of the lid-side elongated hole 11. A cross-sectional view showing the fastening bolt 31 and its fixing nut 31b near the lid-side elongated hole 11.

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a plan view showing one embodiment of a temporary hall cover 100 according to the present invention, and Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1. As shown in the figure, this temporary hall cover 100 comprises a circular cover body 10 on the underside thereof, a cross-shaped reinforcing frame 20, and four slide portions 30, 30, 30, 30.

[0017] The lid body 10 is made of a material that is lighter than conventional cast iron lids and has a moderate strength, such as a checkered steel plate with a non-slip protrusion on the surface (top surface), and although there are no particular limitations on its size, it may have a diameter of 600 to 1000 mm and a thickness of 5 to 10 mm. Although the lid body 10 is a flat plate, it may also have a spherical shape with a gently raised center.

[0018] The reinforcing frame 20 is composed of a first frame 21 made of, for example, an L-shaped cross section angle steel, and a pair of second frames 22, 22 extending laterally from approximately the center of the first frame 21, which are connected in a cross shape. Like the first frame 21, the second frames 22, 22 are also made of angle steel. The reinforcing frame 20 is integrally connected to the underside of the lid body 10 by welding or connecting members such as bolts (not shown) so that their centers are aligned. The vertical and lateral lengths of the reinforcing frame 20 are shorter than the diameter of the lid body 10 (for example, approximately 100 to 300 mm shorter than the diameter of the lid body 10).

[0019] The slide portions 30, 30, 30, 30 are each made of a flat I-shaped angle steel with a length of, for example, about 150 to 200 mm, and are slidable from both ends of the first frame 21 and the respective leading ends of the second frames 22, 22 that make up the reinforcing frame 20 toward the radially outward side of the lid body 10. Figures 3 and 4 are partial enlarged views showing portions S in Figures 1 and 2, and show an example of the structure of the slide portions 30, 30, 30, 30. Note that each slide portion 30, 30, 30, 30 has a similar structure.

[0020] As shown in the figure, the slide portion 30 is positioned parallel to the longitudinal direction of the first frame 21 and the second frame 22, 22 so as to contact the respective leading ends of the frames. A fastening bolt 31 extending from the upper side of an elongated hole 11 formed in the lid body 10 is threadedly engaged with the leading end of the slide portion 30, and an elongated hole 32 extending in the longitudinal direction of the slide portion 30 is formed at the rear end of the slide portion 30 so as to engage with a guide bolt 23 extending through each of the frames 21, 22, 22.

[0021] The temporary hole cover 100 of the present invention, which has such a configuration, has slide sections 30, 30, 30, 30 provided at both ends of the first frame 21 and at each tip of the second frames 22, 22, which can each independently slide in the radial direction of the cover body 10, and therefore can tightly fit (fit) to openings (holes) of various sizes and shapes to close them.

[0022] That is, for example, when fitting a temporary hole lid 100 having a lid body 10 with a diameter of 800 mm to a small-diameter opening (hole) H1 with an inner diameter of 400 mm as shown in Figure 5, the fastening bolt 31 engaging with the elongated hole 11 on the lid body 10 side is loosened as shown in Figures 3(B) and 4(B), and the fastening bolt 31 is moved along the elongated hole 11 to the rear end of the elongated hole 11 (towards the center of the lid body 10). Then, as the fastening bolt 31 moves, the sliding portion 30 slides towards the center of the lid body 10 (reinforcement frame 20).

[0023] This reduces the length (diameter) of the reinforcing frame 20, so that when the lid body 10 is placed over the opening (hole) H1, the reinforcing frame 20 fits securely inside the opening (hole) H1 without interfering with the edge of the opening (hole) H1. If there is a gap between the tip of each slide part 30 and the opening (hole) H1 at this time, the fastening bolts 31 are further moved toward the outer periphery of the lid body 10 until their tips abut the inner wall surface of the opening (hole) H1, and then the fastening bolts 31 are firmly tightened.

[0024] This fixes each slide part 30 in place, eliminating any gap between the tip of each slide part 30 and the opening (hole) H1, and reliably preventing rattle or misalignment. Note that the guide bolts 23 of each frame 21, 22, 22 simply pass through the elongated holes 32 of the slide part 30 and are not threadedly engaged with the slide part 30, so they do not restrict the movement of the slide part 30.

[0025] On the other hand, when this temporary hole cover 100 is adapted to fit a large-diameter opening (hole) H2 with an inner diameter of 700 mm, for example, as shown in Figure 6, after placing the cover body 10 over the opening (hole) H2, loosen the fastening bolts 31 that engage with each elongated hole 11 on the cover body 10, as also shown in Figures 3 (B) and 4 (B), and move each fastening bolt 31 along the elongated hole 11 to the tip of the elongated hole 11 (to the outer periphery of the cover body 10).

[0026] Then, as the fastening bolts 31 move, the slide parts 30 slide toward the outer periphery of the lid body 10 (reinforcing frame 20), and once their tips come into contact with the inner wall surface of the opening (hole) H2, the fastening bolts 31 are firmly tightened. This fixes the slide parts 30 in place, eliminating any gaps between the tips of the slide parts 30 and the large-diameter opening (hole) H2, allowing the entire reinforcing frame 20 to fit snugly within the opening (hole) H2.

[0027] In this way, the temporary hole lid 100 of the present invention can fit tightly to openings (holes) H of various sizes because the slide portion 30 provided on the underside of the lid body 10 together with the reinforcing frame 20 slides radially outward or widthwise outward from the reinforcing frame 20 to abut against the inner surface of the opening (hole) H. In addition, the size of the reinforcing frame 20 can be changed from the top side of the lid body 10, making the adjustment easy.

[0028] Furthermore, since it is not necessary to form a large number of holes in the lid body 10, there is little risk of large amounts of rainwater or earth and sand flowing into the opening (hole) H. Although the embodiment shown in Figures 1 to 6 shows an example of a circular opening (hole) H, it is also applicable to a rectangular opening (hole) H3 such as a side gutter as shown in Figure 7, and can exert the same functions and effects.

[0029] 8 and 9, if any or all of the slide portions 30 are T-shaped, the number of contact points between the reinforcing frame 20 and the opening (hole) H increases, allowing for more stable installation of the lid main body 10. That is, in the example shown in FIGS. 8 and 9, the slide portions 30 on the second frame 22, 22 side are T-shaped, and each slide portion 30 has three elongated holes 11, and fastening bolts 31 are passed through the elongated holes 11, 11, 11 and screwed into the slide portion 30. This increases the number of contact points between the reinforcing frame 20 and the opening (hole) H from four to six, improving stability, and therefore makes it possible to omit the slide portion 30 on the first frame 21 side.

[0030] As another example, as shown in Fig. 10, the reinforcing frame 20 may be Y-shaped and the slide portions 30 may abut the openings (holes) H at three locations, or conversely, the number of frames may be increased to five or more and arranged radially. Furthermore, it is not necessary to provide slide portions 30 at the tips of all frames, and similar effects can be expected even if slide portions 30 are provided at only two locations, at least at the tips of the opposing second frames 22, 22, as shown in Fig. 11.

[0031] In Figure 1, symbol 40 denotes a keyhole into which a special tool is inserted to lift the temporary hole cover 100 and attach / detach it to / from hole H, and symbol 50 denotes a fixing hole used to fix the temporary hole cover 100 to the opening (hole) H side after installation using a bolt or the like (not shown).

[0032] 12, multiple recesses 11a into which the head of the fastening bolt 31 fits may be formed along the edge of the elongated hole 11 on the lid body 10. That is, in the example shown in the figure, the fastening bolt 31 is provided with a ring-shaped flat washer 31a, and seven circular recesses 11a of a size that just fits the flat washer 31a are provided at equal intervals along the edge of the elongated hole 11. This reliably prevents the fastening bolt 31 from shifting position even if it loosens slightly due to vibrations caused by, for example, a passing vehicle. Furthermore, by partially or completely embedding the flat washer 31a and the bolt head in these recesses 11a, the amount of protrusion of the fastening bolt 31 from the top surface of the lid body 10 can be reduced or eliminated.

[0033] 13, if a fixing nut 31b is welded to the slide portion 30 and the fastening bolt 31 is threaded onto this fixing nut 31b, the thickness of the angle steel that constitutes the slide portion 30 can be reduced, thereby achieving weight reduction. That is, as described above, the fastening bolt 31 is threaded directly onto the slide portion 30 made of angle steel, and in order to thread securely, the angle steel needs to be thick to a certain extent, but by using the fixing nut 31b in this way, it is no longer necessary to thread it directly onto the slide portion 30, and the thickness can be kept to a necessary minimum.

[0034] 10...Cover body 11...Elongated hole 11a...Recess 20...Reinforcing frame 21...First frame 22...Second frame 23...Guide bolt 30...Sliding portion 31...Fastening bolt 31a...Flat washer 31b...Fixing bolt 32...Elongated hole 40...Keyhole 50...Fixing hole 100...Temporary cover for hole H, H1 to H3...Opening (hole)

Claims

1. A temporary hall lid that is placed over an opening to close it, comprising: a circular or rectangular lid body that is larger than the opening; a reinforcing frame provided on the underside of the lid body so as to be positioned within the opening; and a sliding part that slides radially outward or widthwise outward from the reinforcing frame to abut against the inner surface of the opening, wherein the sliding part is supported on the underside of the lid body by screwing onto a fastening bolt that is inserted from the top side of the lid body through an elongated hole formed in the lid body so as to extend in the radial or width direction.

2. A temporary hole cover as claimed in claim 1, characterized in that a plurality of recesses into which the heads of the fastening bolts fit are formed along the edge of the elongated hole.

3. A temporary hall cover according to claim 1, characterized in that the reinforcing frame extends in a cross or Y shape from approximately the center of the cover body.

4. A temporary hall cover as claimed in claim 3, characterized in that the slide portion is I-shaped or T-shaped and extends in the radial or width direction of the cover body.

5. A temporary hall cover according to any one of claims 1 to 4, characterized in that the cover body is made of checkered steel plate.

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