Drain cover with anti-theft device

Abstract

The present invention provides a ditch cover with an anti-theft device that allows the operator to visually confirm the movement of the extrusion plate as it is pushed outward on the stepped surface of the gutter, and to securely fix and hold the ditch cover without damaging the gutter, even in gutters without a receiving frame. [Solution] A metal plate-shaped groove cover 1 is formed by connecting members 14 perpendicularly to a plurality of strip-shaped main members 11 arranged upright in the width direction with gaps S between them, and closing both sides of the main members with side bracing members 12 to form a rectangle in plan view. The groove cover has a flat plate portion arranged horizontally in the lower edge area between adjacent main members and a vertical plate portion 4 that extends vertically upward or inclined backward from a bent portion that bends at its rear end, and a base plate body 2 fixed to the part of the main member near the side bracing member, a bolt shaft fixed upright in the central area of ​​the upper surface of the flat plate portion, and a through hole 60 into which the bolt shaft is loosely inserted is provided in the central area of ​​the main plate portion 61, and a sub-plate portion 62 that bends in an L-shape in side view extends from the main plate portion. The device comprises an extruded plate 6, a nut 7 that screws onto the tip of a bolt shaft loosely inserted into a through-hole in the extruded plate, and a notch formed by cutting out the lower edge portion of a side support material near the base plate. Initially, when the nut is screwed onto the bolt shaft and tightened, the rear end portion of the main part of the plate contacts the vertical surface 4g of the vertical plate portion. In a side view with a groove cover installed in the side groove, the main part of the plate slopes downward toward the nearby side support material, and the secondary part of the plate extending from the front end portion of the main part of the plate passes through the notch and is positioned upward. As the nut is tightened, the rear end portion slides downward along the vertical surface, reducing the downward slope angle of the main part of the plate, and pushing the main part of the plate forward.

Description

Technical Field

[0004] , , , , , ,

[0001] The present invention relates to a manhole cover installed in a gutter or a catch basin, etc., and a manhole cover with an anti-theft device useful for preventing theft.

Background Art

[0002] For manhole covers covering side gutters provided on the road surface, etc., metal gratings with good drainage and high mechanical strength are widely used. However, in recent years, this type of metal manhole cover has been suffering from theft damage. When theft damage occurs, since there is no manhole cover that should originally be there, pedestrians and vehicles may fall into the side gutter, and there is also a risk of developing into a serious accident. Among these, an anti-theft device for gratings effective for manhole covers with raised members has been proposed (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003] [[ID=2-seven]]

Patent Document 1

Disclosure of the Invention

Problems to be Solved by the Invention

[0004] However, the anti-theft device for gratings of Patent Document 1 has difficulty enhancing the anti-theft effect unless there is a heavy concrete manhole cover next to the manhole cover with a raised member installed in the side gutter. On the other hand, the applicant of the present application previously filed an application for a screwed and tightened lid body of a protruding member for anti-theft (Japanese Patent Application Laid-Open No. 2024-34942). It has a structure in which the second plate portion of the protruding member abuts against the side wall located below the manhole cover and protrudes. The tip portion of the second plate portion abuts against the side wall of the side gutter and protrudes, and although it can firmly and reliably attach and fix the lid body that closes the upper surface opening of the side gutter, it is a screwed and assembled lid body of the protruding member. However, there was a problem in that it was difficult for workers working from above the cover, such as a drain cover, to see whether the tip of the second plate section located below the cover was properly making contact with the side wall and bracing against it.

[0005] This invention aims to solve the above problems by providing a ditch cover with an anti-theft device that allows the operator to visually confirm the movement of the extrusion plate as it is pushed outwards on the horizontal part of the receiving frame or on the stepped surface of the side ditch as the operator tightens the nut, and that can securely fix and hold the ditch cover in side ditches without damaging them, even if there is no receiving frame. [Means for solving the problem]

[0006] To achieve the above objective, the first aspect of the present invention provides a metal plate-shaped groove cover formed in a grid pattern by connecting members perpendicularly to a plurality of strip-shaped main members arranged upright in the width direction with gaps between them, and closing both sides of the main members with side bracing members to form a rectangular shape in plan view; a base plate fixed to the part of the main member near the side bracing member, comprising a flat plate portion arranged horizontally in the lower edge area between adjacent main members of the groove cover and a vertical plate portion extending vertically upward or inclined backward from a bent portion that bends at its rear end; a bolt shaft fixed upright in the central area of ​​the upper surface of the flat plate portion; an extruded plate having a through hole into which the bolt shaft is loosely inserted in the central area of ​​the main plate portion, and a sub-plate portion extending from the main plate portion that bends in an L-shape in side view; and the extruded plate The anti-theft groove cover comprises a nut that screws onto the tip of the bolt shaft, which is loosely inserted into the through hole of the plate, and a notch formed by cutting out the lower edge portion of the side support material near the base plate, wherein in the initial stage of screwing the nut onto the bolt shaft and tightening it, the rear end portion of the main plate portion hits the vertical surface of the vertical plate portion, and in a side view of the groove cover installed in the side groove, the main plate portion slopes downward toward the nearby side support material, and the sub-plate portion extending from the front end portion of the main plate portion is arranged upward through the notch, and as the tightening of the nut progresses, the rear end portion slides downward along the vertical surface, the downward slope angle of the main plate portion decreases, and the main plate portion is pushed forward. The second embodiment of the present invention, a drain cover with an anti-theft device, is characterized in that, in the first embodiment, the base plate, the bolt shaft, the extruded plate, and the nut are provided near the four corners of the rectangular shape of the drain cover in plan view. The third embodiment of the present invention, a drain cover with an anti-theft device, is characterized in that, in the first or second embodiment, the upright plate portion is bent at an obtuse angle from the rear end of the flat plate portion in a side view, and extends with an upward sloping rearward inclination, and a bend boundary portion is provided at the upper end of the inclined plate portion, from which a vertical portion with a vertical surface extends. The fourth embodiment of the present invention, a drain cover with an anti-theft device, is characterized in that, in the third embodiment, in a side view of the extruded plate, a side-view arc-shaped curve is formed on the rear end portion of the lower side of the main part of the plate, which corresponds to the upright surface of the upright plate portion. The fifth embodiment of the present invention, a drain cover with an anti-theft device, is characterized in that, in the fourth embodiment, an arc-shaped curve is formed on the protruding end portion of the outer side of the sub-part of the plate in a side view. [Effects of the Invention]

[0007] The anti-theft device for the drain cover of this invention allows workers to easily observe from the ground the movement of the push plate as it is pushed out onto the stepped surface of the drain as the nut is tightened. Furthermore, even without a receiving frame, the drain cover can be securely fixed and held in place by contacting the vertical surface of the step or the vertical part of the receiving frame without damaging the drain. This not only improves work efficiency and protects the drain, but the structure of this anti-theft device also prevents damage to the vertical surface of the step of existing drains without receiving frames, and allows for easy and orderly arrangement of multiple drain covers in a straight line, thus contributing to an improved landscape. [Brief explanation of the drawing]

[0008] [Figure 1] This is a plan view of Embodiment 1, showing a base plate body on which a bolt shaft is erected fixed to a groove cover. [Figure 2] This is an exploded perspective view of the base plate, bolt shaft, extruded plate, washer, and nut. [Figure 3] This is a plan view of an actual trench cover with the slit width of Figure 1 narrowed to half, to which a base plate with a bolt shaft is fixed. [Figure 4] This is a plan view of an extruded plate, with a through-hole loosely inserted into the bolt shaft shown in Figure 1, placed on a base plate. [Figure 5] This is a plan view showing a nut screwed onto the tip of the bolt shaft in Figure 4 and tightened. [Figure 6] This is a view from the line VI-VI in Figure 4, with a nut and washer added. [Figure 7] Figure 6 shows a cross-sectional view of the bolt shaft with a nut screwed onto it, before the nut is tightened. [Figure 8] Figure 7 shows the final state where the inclination angle has decreased as the nut has been tightened, as viewed from the line VIII-VIII in Figure 5. [Figure 9] This is a view from the line IX-IX in Figure 6. [Figure 10] This is a view taken along line XX in Figure 8. [Figure 11] Figure 3 is a partial perspective view showing an extruded plate with bolt shafts loosely inserted into through holes, placed on a base plate. [Figure 12] This is a cross-sectional view corresponding to Figure 8 in Embodiment 2. [Figure 13] In Embodiment 3, (a) is a side view of the extrusion plate, and (b) is a cross-sectional view corresponding to Figure 7. [Figure 14] This is a cross-sectional view corresponding to Figure 8, using a flat plate-like body that corresponds to an extruded plate without a plate sub-part. [Modes for carrying out the invention]

[0009] The following describes in detail the anti-theft device attached to the drain cover according to the present invention. Figures 1 to 13 show one form of the anti-theft device attached to the drain cover according to the present invention. Figure 1 is a plan view of Embodiment 1, in which the base plate with a bolt shaft is fixed to the drain cover. Figure 2 is an exploded perspective view of the base plate, bolt shaft, extruded plate, washer and nut. Figure 3 is a plan view of the base plate with a bolt shaft fixed to an actual drain cover. Figure 4 is a plan view of the bolt shaft in Figure 1 with a through hole loosely inserted and the extruded plate placed on the base plate. Figure 5 is a plan view of the bolt shaft in Figure 4 with the nut screwed on and tightened. Figure 6 is a view along the line VI-VI in Figure 4. Figure 7 is a cross-sectional view of the bolt shaft in Figure 6 before the nut is screwed on and tightened. Figure 8 is a cross-sectional view of Figure 7. Figure 5 is a view taken along the line VIII-VIII in the final state where the inclination angle is reduced by tightening the nut, Figure 9 is a view taken along the line IX-IX in Figure 6, Figure 10 is a view taken along the line XX in Figure 8, Figure 11 is a partial perspective view of the extruded plate with the bolt shaft loosely inserted into the through hole placed on the base plate, Figure 12 is Embodiment 2, a cross-sectional view corresponding to Figure 8, and Figure 13 is Embodiment 3, where (a) is a side view of the extruded plate and (b) is a cross-sectional view corresponding to Figure 7. In Figures 1 and 3, the gutter 8 is not shown, and in Figures 9 and 10, the nut 7 and washer SW are not shown. Note that each figure is simplified and the essential parts of the invention are highlighted for clarity.

[0010] (1) Embodiment 1 This embodiment is a drain cover A with an anti-theft device applied to a drain cover 1 of a grating as shown in Figures 1 to 11, and comprises a drain cover 1, a base plate 2 for the anti-theft device J, a bolt shaft 5, an extrusion plate 6, a nut 7, and a washer SW. The trench cover 1 is a metal plate-shaped body formed in a grid pattern by connecting members 142 perpendicularly to multiple strip-shaped main members 11 that are arranged upright in the width direction with gaps S between them, and closing both sides of the main members 11 with side bracing members 12 to form a rectangle in plan view. A notch 121 is formed in the side bracing member 12 near the base plate 2 by cutting out the lower edge 12b of the side bracing member (details will be described later). The trench cover 1 here is a rectangular metal grating in plan view formed by orthogonally arranging connecting members 14 (also called crossbars), which are metal rod-shaped members twisted on the main member 11, in a lattice pattern (Fig. 1). It is a known trench cover 1 with a rectangular plate shape with a standardized overall shape, comprising a main member 11, side abutting members 12, end plates 13, and connecting members 14. Specifically, a plurality of main members 11 made of strip plates with an I-shaped cross-section, commonly called I-bars, are arranged in parallel with the width direction vertical. With the end plates 13 at both ends of the main member 11, the main member 11 and the connecting member 14 are then fixed by electric pressure welding to form a lattice pattern, and strip-shaped side abutting members 12 are fixed to both side lateral directions where the end faces of the main members 11 are aligned, and assembled into a rectangular plate-shaped trench cover 1 as shown in Fig. 1. The lower edge 11b of the main member protrudes downward further than the lower edge 12b of the side abutting member (Fig. 9). The trench cover 1 is for covering the upper surface opening (trench opening) of a side trench 8 or the like while ensuring water permeability. The symbol S indicates a gap (hereinafter also referred to as a "slit") formed by arranging the main member 11 and the connecting member 14 in a lattice pattern.

[0011] In fact, in the actual trench cover 1, the slit S is formed by arranging the main members 11 as shown in Fig. 3, and Figs. 1, 4, 5, 9, and 10 are simplified diagrams with the number of main members 11 reduced for easier understanding. In reality, as shown in Figs. 3 and 11, a part of the main member 11 where the base plate body 2 is arranged is cut off, and in the arranged space area of the trace of the cut-off main member 11, the upright plate portion 4 of the base plate body 2 abuts against the end face of the cut-off main member 11. And a flat plate portion 3 is horizontally arranged in the lower edge 11b area between two adjacent main members 11 (see Fig. 9). Even in such a case, it is considered that "the flat plate portion 3 is horizontally arranged in the lower edge 11b area between adjacent main members 11 of the trench cover 1" in the present invention.

[0012] The base plate body 2 is a plate body having a flat plate portion 3 and a standing plate portion 4 (Fig. 2). The base plate body 2 is fixed to the portion of the main member 11 near the side contact member 12 as shown in Fig. 6. The flat plate portion 3 is rectangular in plan view and is a plate portion horizontally arranged in the lower edge 11b region between adjacent main members 11 of the disk-shaped groove lid 1 (Fig. 9). The standing plate portion 4 is a plate portion that rises obliquely backward from the bending portion F that bends at the rear end 31 of the flat plate portion 3. In plan view, a part of the slit S formed between adjacent main members 11 is blocked by the flat plate portion 3 and the standing plate portion 4 (Figs. 1 and 9). Here, the rear end 31 and the rear part of the "rear end of the flat plate portion horizontally arranged in the lower edge region between adjacent main members of the groove lid" as referred to in the present invention mean that, in Fig. 6, for the flat plate portion 3 horizontally arranged in the lower edge 11b region between adjacent main members 11 of the groove lid 1, it is the right end and the right part of the flat plate portion 3 connected to the standing plate portion 4. For other members, in the side view of the groove lid A with anti-theft device covering the side groove 8 in Figs. 6 to 8, unless otherwise specified, the tip and the tip portion towards the center in the groove width direction of the groove lid 1 (right side in the figure) are the rear end and the rear part, and the tip and the tip portion towards the side contact member 12 and the receiving frame vertical portion 92 on both sides from the center in the width direction of the groove lid 1 are the front end and the front part. Also, in Figs. 6 to 8, the left side of the paper surface is regarded as the outer side, and the upper side and the upper part of the paper surface are literally the upper side and the upper part in the present invention, and the lower side and the lower part of the paper surface are the lower side and the lower part.

[0013] The base plate body 2 is a horizontally long rectangular plate as shown in Fig. 2, with the vicinity of the center in its longitudinal direction as the bending portion F, and from the bending portion F, a standing plate portion 4 that rises vertically or obliquely backward with respect to the flat plate portion 3 arranged on the left is formed. In the side view of the standing plate portion 4 of the present embodiment, it is a slant plate portion 41 that bends at an obtuse angle with respect to the flat plate portion 3 from the rear end 31 of the flat plate portion 3 and extends obliquely backward, and a bending boundary portion 43 is provided at the upper end of the slant plate portion 41, and further a vertical portion 42 extends from here to form it. The base plate body 2 has the same shape in the plate width direction in side view. The vertical plate section 4 may consist only of a vertical plate section 42 that rises vertically or a slanted plate section 41 (see Figure 14), but a bending boundary section 43 is provided in the middle of the slanted plate section 41 as it extends with a rearward upward slope, and the vertical section 42 with a vertical plane 42g extends from there. By providing the slanted plate section 41, the sliding descent of the main plate section 61 is made smoother when tightening the nut 7. A slit S for rainwater flow is formed between the main members 11, but in the area where the base plate body 2 is placed, the base plate body 2 obstructs the flow of rainwater, so the opening 10 in plan view has a smaller area for rainwater flow than the slit S (Figure 1). By providing the vertical section 42, the opening 10 is made slightly larger to improve water permeability. Then, the end face of the main member 11, which is cut shorter than a normal main member 11 by the amount that the base plate 2 is placed on the rear surface 4k of the vertical plate section 4 as shown in Figure 3 (see Figures 3 and 11), comes into contact with the main member 11 and the vertical plate section 4, and the main member 11 and the vertical plate section 4 are welded together.

[0014] The upper end surface 4a of the vertical plate portion 4 reaches the upper edge 11a of the main member 11 or is slightly lower than the upper edge 11a of the main member as shown in Figure 6. The base plate body 2 is positioned so that the flat plate portion 3 is horizontally placed in the lower edge 11b area between adjacent main members 11 of the groove cover 1, and both side edges in the width direction of the base plate body 2 are fixed to the adjacent main members 11 close to the side backing material 12 of the groove cover 1. The base plate body 2 is horizontally fixed with the lower surface of the flat plate portion 3 along the lower edge 11b of the main member near the side backing material 12 (Figure 9). Here, the front end edge 33 of the flat plate portion 3 is positioned directly below the rear surface 12k of the side backing material 12 (Figures 6 and 7). Incidentally, in this groove cover 1, a notch 121 is provided to facilitate the insertion and setting of the plate sub-part 62 of the extruded plate 6 (details described later), on which the bolt shaft 5 is loosely inserted into the through hole 60, between the upper surface 3a of the flat plate and the lower edge 12b of the side support material located right next to the front edge 33 of the flat plate, as shown in Figure 6. This also facilitates the forward and backward movement of the extruded plate 6. The notch 121 is formed by cutting out the lower edge portion 12b of the side support material 12 near the base plate body 2 (Figure 11). A through hole for the bolt shaft 5 is provided in the central area 32 of the upper surface 3a of the horizontally arranged flat plate section (Figure 2).

[0015] The bolt shaft 5 is a shaft body in which a male thread is provided on the shaft portion that is fixed upright to the central area 32 of the upper surface of the flat plate portion 3 by inserting its base end portion 51 into the through hole (Figures 2 and 6). In this embodiment, the bolt shaft 5 is made by cutting the bolt head of a general-purpose bolt and welding the base end portion 51 that is passed through the through hole as shown in Figure 6 to the flat plate portion 3. The bolt shaft 5 stands almost vertically with its tip portion 52 pointing upward relative to the flat plate portion 3. The symbol wd indicates the welded portion.

[0016] The extruded plate 6 comprises a main plate portion 61 and a sub-plate portion 62. In this embodiment, the extruded plate 6 is formed in a horizontally elongated rectangular plate as shown in Figure 2, with a bending line 63 provided so that the horizontal length of the main plate portion 61 is longer than that of the sub-plate portion 62, so that the main plate portion 61 and the sub-plate portion 62 form an L-shape in side view. A through hole 60 into which a bolt shaft 5 is loosely inserted is provided in the central area of ​​the main plate portion 61, and the sub-plate portion 62 extends from the main plate portion 61, bending in an L-shape in side view as shown in Figure 6. Here, the main plate portion 61 is assumed to have the center of the through-hole 60 located slightly towards the rear end from the center of the rectangular plate portion as shown in Figure 2. The through-hole 60 is an elongated elliptical hole as shown in the figure, which is long in the front-to-back direction. The front-to-back length of the main plate portion 61 is set to be slightly longer than the distance from the bent portion F of the base plate body 2 fixed to the groove cover 1 to the outer surface of the side bracing material 12 that is closer (Figures 2 and 8). Even in the state shown in Figure 8, the bolt shaft 5 is kept loosely inserted in the through-hole 60.

[0017] Then, when the main plate portion 61, with the bolt shaft 5 loosely inserted into the through hole 60, is placed on the base plate 2, the rear end portion 611 of the main plate portion 61 contacts the vertical surface 4g of the vertical plate portion 4 (in this case, the inclined surface 41g of the inclined plate portion 41), as shown in Figure 6. Furthermore, the protruding end portion 621 of the sub-plate portion 62 is positioned to protrude slightly forward of the side support material 12, to the left of the page in Figure 6, and in the side view of Figure 6 with the groove cover 1 installed on the side ditch 8, the main plate portion 61 slopes downward toward the nearby side support material 12 and the vertical part 92 of the receiving frame. In this embodiment shown in Figures 6 to 8, where the groove cover A with the anti-theft device is used to cover the upper opening of the side ditch 8, which has a receiving frame 9 mounted and fixed on the stepped surface 82, the sub-plate portion 62, which is bent in an L-shape from the main plate portion 61, faces upward, and its protruding end portion 621 contacts the vertical part 92 of the receiving frame. In the diagram, the symbol α represents the gap between the vertical part 92 of the receiving frame placed in the gutter 8 and the gutter cover 1 that covers the gutter 8. It indicates the small gap that is necessary for the mounting set of the gutter cover 1 to the gutter 8.

[0018] Figure 1 is a plan view in which a base plate body 2 with a bolt shaft 5 is welded and fixed to the groove cover 1, while Figure 4 is a plan view in which the extruded plate 6 rests on the base plate body 2. Since the width of the short side of the rectangular extruded plate 6 is set to be slightly smaller than the width of the base plate body 2 (Figures 4 and 9), the advance of the extruded plate 6 becomes smoother, and the tightening of the nut 7 proceeds smoothly. Furthermore, in a side view, the extruded plate 6 has a curved shape 611R formed on the lower rear end portion 611 of the main plate portion 611 which corresponds to the vertical surface 4g of the vertical plate portion 4 (Figures 2 and 6), so that the extruded plate 6 can easily slide on the slope 41g, making it easier to tighten the nut 7. Also, even if the extruded plate 6 tries to rotate together when the nut 7 is tightened, the adjacent main members 11 that fix the base plate body 2 restrict this, so that the tightening of the nut 7 proceeds smoothly.

[0019] The nut 7 is a known screw component that screws onto the tip 52 of the bolt shaft 5, which is loosely inserted into the through hole 60 of the extruded plate 6. Here, a cap nut 7 as shown in the figures is used. Furthermore, a washer SW consisting of a spring washer as shown in Figures 2 and 6 is provided.

[0020] In this embodiment, a base plate 2, a bolt shaft 5, an extruded plate 6, a nut 7, and a washer SW for the anti-theft device J are provided near the four corners of the rectangular trench cover 1 in the arrangement described above. As shown in Figures 4 and 6, near the four corners of the rectangular trench cover 1, each base plate 2 with a bolt shaft 5 is positioned horizontally in the lower edge 11b area between adjacent main members 11, and fixed to the main member 11. Slightly above the lower edge 11b of the main member, the base plate 2 is welded to the main member 11 with the upper surface 3a of the flat plate 3 horizontal.

[0021] Thus, the base plate body 2 with the bolt shaft 5 is fixed and integrated to form a groove cover 1. To make it function as a groove cover A with an anti-theft device, for example, the groove cover 1 with the base plate body 2 with the bolt 5 fixed to it is used to cover the side groove 8. First, an extruded plate 6, with the bolt shaft 5 loosely inserted into the through hole 60, is placed on the base plate body 2. The main part 61 of the extruded plate 6 has its rear end 611 locked to the vertical surface 4g and is positioned so as to slope downward toward the side backing material 12 near the main part of the plate (Figure 6).

[0022] Then, from the state shown in Figure 6, the washer SW is loosely fitted onto the tip 52 of the bolt shaft 5, and the nut 7 is screwed onto the tip 52 of the bolt shaft and tightened. In the initial stages of tightening, the main plate portion 61, which is in contact with the vertical surface 4g of the vertical plate portion 4, tilts downward toward the nearby side support material 12, as shown in the side view in Figure 7. In this embodiment, the rear end portion 611 of the main plate portion 61 is in contact with the slope 41g of the slope portion 41. In this state shown in Figure 7, the extruded plate 6 is tilted downward toward the side support material 12 at an angle θ1, as shown, and the sub-plate portion 62 extending from the front end portion 612 of the main plate portion 61 is positioned upward toward the protruding end portion 621, passing through the notch 121.

[0023] Then, as the tightening of the nut 7 progresses from the initial tightening of the nut 7 onto the bolt shaft 5, the rear end portion 611 of the plate slides downward along the vertical surface 4g (more specifically, the inclined surface 41g), and the angle of inclination of the downward slope of the extruded plate 6 becomes small, at an angle θ2 (Figure 8). Angle θ2 < θ1. As the angle decreases to θ2, the main portion 61 of the extruded plate 6 is pushed outward from the side of the groove cover 1. In Figure 8, the main portion 61 of the plate is pushed to the left on the flat plate portion 3 and pushed forward through the notch 121 cut out from the lower edge 12b of the side backing material. The main portion 61 of the plate is pushed outward from the side backing material 12 of the groove cover, that is, towards the vertical portion 92 of the side groove. Initially, as shown in Figure 6, the plate thickness n of the plate sub-part 62 in a plan view is as shown in Figure 4. However, when the nut 7 in Figure 8 is tightened, the plate sub-part 62 stands upright, and as shown in Figure 5, it appears as a plate thickness M that is greater than the plate thickness n in a plan view.

[0024] The side support material 12 closest to the base plate 2 between the main members 11 to which the base plate 2 is fixed has a notch 121 formed by cutting out its lower edge 12b (Figures 7 and 11), allowing the main plate portion 62 to be smoothly pushed outward (sideways) through the notch 121. In this embodiment, the receiving frame 9 is placed and fixed on the stepped surface 82 of the side groove 8. At the initial stage of screwing the nut 7 in Figure 7 onto the bolt shaft 5 and tightening it, the protruding end portion 621 of the main plate portion 62 is already in contact with the vertical portion 92 of the receiving frame. Therefore, even if the protruding end portion 621 moves slightly upward due to the pushing out of the main plate portion 61, the sub-plate portion 62 rotates clockwise in Figure 8 around the protruding end portion 621, increasing the surface area of ​​the outer surface (front surface) 62f of the sub-plate portion 62 that contacts the vertical surface 92 of the receiving frame. At this time, due to the clockwise rotation described above, the angle of refraction of the L-shaped sub-plate 62 relative to the main plate 61 becomes somewhat smaller as the main plate 61 is pushed out. Then, in addition to the pushing force of the main plate 61, the restoring force of the refraction angle also acts, causing the sub-plate 62 to be strongly pressed against the surface of the vertical portion 92 of the receiving frame 9 provided on the side ditch step surface 82 with its outer surface 62f, as shown in Figure 8. During the process of setting the extrusion plate 6, from Figure 6 to Figures 5 and 8, the contact surface area of ​​the plate sub-part 62 with the vertical surface 92 of the receiving frame increases. As the nut 7 is tightened onto the bolt shaft 5, in addition to the forward force of the plate main part 61, the contact pressure of the plate sub-part 62 with the vertical surface 92 of the receiving frame increases, and the area of ​​the outer surface (front surface) 62f pressing against the vertical part 92 of the receiving frame also increases. Eventually, the frictional force that hinders movement between the receiving frame 9 and the extrusion plate 6 increases due to the increased pressure and area, causing the two to become joined and integrated. The receiving frame 9, which is attached and fixed to the stepped surface 82 of the side ditch, is secured by anti-theft devices J such as extruded plates 6 provided near the four corners of the rectangular shape of the ditch cover 1 in plan view, thus creating a desired ditch cover A with anti-theft devices.

[0025] Next, we will describe a method for fixing and holding the ditch cover A with the anti-theft device to a receiving frame 9 installed on the stepped surface 82 of the side ditch 8. First, the worker visually confirms that the extruded plate 6 is placed on the base plate 2 so that it is approximately in the state shown in Figure 4, and then screws nuts 7 onto each bolt shaft 5 near the four corners of the groove cover on the top, bottom, left, and right sides of the same figure (Figure 6), thereby securing the initial state before tightening the nuts 7 (Figure 7). At this time, each main plate portion 61 of the extruded plate 6 is in contact with the vertical surface 4g of each vertical plate portion 4, causing the extruded plate 6 to be inclined downward toward the side support material 12.

[0026] Afterward, the worker visually checks the degree of extrusion of each extrusion plate 6 and adjusts the balance, then tightens the nuts 7 that are screwed onto each bolt shaft 5 near the four corners of the trench cover 1. As tightening progresses, the rear end portion 611 of the main plate portion 61 slides downward along the vertical surface 4g, reducing the inclination angle of the downward slope of the extrusion plate 6, and the main plate portion 61 of the extrusion plate 6 is pushed forward (to the left in Figure 7) passing under the side backing material 12. While visually checking, the worker confirms the degree of protrusion of the main plate portion 61 advancing beyond the side backing material 12 and the degree of contact of the sub-plate portion 62 with the receiving frame vertical portion 92 at four locations near the four corners of the trench cover 1. Then, the degree of protrusion of the main plate portion 61 is slightly increased by tightening the nuts 7, and the receiving frame vertical portion 92 resting on the side trench step surface 82 is firmly pressed down by the extrusion plate 6 (Figure 8). The pressure force between the outer surface 62f of the plate sub-part 62 and the surface of the vertical part 92 of the receiving frame is further increased. Thus, a desirable anti-theft device-equipped drain cover A is obtained that can securely and evenly fix and hold the drain cover 1 at all four corners (Figure 4). The symbol W represents the flow path of the side ditch 8, the symbol 811 represents the top surface of the U-shaped side ditch, the symbol 91 represents the horizontal part of the receiving frame, and the symbol AN represents the anchor.

[0027] (2) Embodiment 2 The anti-theft drain cover A of this embodiment has the same configuration as Embodiment 1, but is applied to a drain ditch 8 where a receiving frame 9 is not installed, as shown in Figure 12. Some existing drain ditches 8 do not have a receiving frame 9. Even for such drain ditches 8 without a receiving frame 9, the anti-theft drain cover A is an excellent product that can be firmly fixed to the drain ditch 8 by pressing the outer surface 62f of the plate sub-part 62 against the stepped vertical surface 822 of the drain ditch 8 with surface pressure, as shown in Figure 12, and integrating with the drain ditch 8 without damaging the drain ditch.

[0028] (3) Embodiment 3 This embodiment is a groove cover A with an anti-theft device, as shown in Figure 13, in which a curved shape 621R is formed on the outer surface side of the protruding end portion 621 of the plate sub-part 62 of Embodiment 1 when viewed from the side. As described above, in the movement from Figure 6 to Figure 8, the plate sub-part 62 rotates around the tip portion 621, and a curved shape 621R is formed on the outer surface of the tip portion 621 related to the plate sub-part 62 when viewed from the side. Therefore, it can be applied more easily to existing side ditches 8 as shown in Figures 12 and 13, which do not have a receiving frame 9. The formation of the curved shape 621R results in a ditch cover A with an anti-theft device that more completely suppresses the problem of damaging the vertical step surface 822 of the side ditches 8. Other configurations are the same as in Embodiment 1, and their description is omitted. The same reference numerals as in Embodiment 1 indicate the same or corresponding parts.

[0029] (4) Effects In the anti-theft ditch cover A of this invention, as configured in this way, as the tightening of the nut 7 progresses, the rear end 611 of the plate slides downward along the vertical surface 4g, and the main part 61 of the extruded plate 6 is pushed outwards (to the left in Figure 8) on the horizontal part 91 of the receiving frame. The movement of the main part 61 of the plate being pushed outwards can be easily observed by the worker from the ground above the horizontal part 91 of the receiving frame. The movement of the main part 61 of the plate is visible not only on the flat plate part 3 but also in the gap α between the ditch cover 1 that covers the side ditch 8 and the vertical part 92 of the receiving frame, so it can be easily observed by the worker from the ground. While observing the movement of the main part 61 of the plate, and furthermore the outer surface 62f of the sub-part 62 of the plate, and while confirming the tightening of the nut 7, the sub-part 62 of the plate can be smoothly and securely fixed and held against the ditch cover receiving frame 9. The main plate portion 61, visible on the flat plate portion 3 horizontally fixed to the lower edge 11b of the main member, extends approximately horizontally outward, visible into the gap α between the gutter cover 1 that covers the side gutter 8 and the vertical portion 92 of the receiving frame. This makes it easier for workers to see the movement of the main plate portion 61 and the upward-facing sub-plate portion 62, allowing the installation and fixing of the gutter cover 1 to the side gutter 8 to proceed smoothly.

[0030] Furthermore, as the movement of the extrusion plate 6 from Figure 6 to Figure 7 progresses, the main part of the plate 61 advances outward as the nut 7 is tightened, causing the sub-part of the plate 62, whose protruding end 621 is in contact with the vertical part 92 of the receiving frame, to rotate around the protruding end 621, increasing the surface pressure on the vertical part 92 of the receiving frame as shown in Figure 8. As the sub-part of the plate 62 rotates around the protruding end 621, the L-shaped bending angle formed by the main part of the plate 61 and the sub-part of the plate 62 becomes somewhat smaller as shown in Figure 8. In addition to the increase in the surface pressure of the sub-part of the plate 62 on the vertical part 92 of the receiving frame generated by the forward force of the main part of the plate 61, a restoring force is also generated by this reduced bending angle, resulting in extremely high frictional resistance when trying to remove the groove cover A with the anti-theft device. In this state, it is difficult to remove, and thus it is extremely effective in preventing theft. It has the advantage of being able to securely hold the ditch cover A with the anti-theft device in place on the ditch cover receiving frame 9 for an extended period of time.

[0031] Here, even if the extruded plate, which comprises a main plate portion 61 and a sub-plate portion 62, is replaced with only the flat plate-like body m shown in Figure 14, which corresponds to the main plate portion 61, its front end portion m12 will push against the vertical receiving frame portion 92 of the side ditch 8, thereby securely fixing and holding the ditch cover 1 in the side ditch 8. However, in the case of existing side ditches 8 that do not have a receiving frame 9 as shown in Figure 12, the pressing force of the flat plate-shaped body m is concentrated on the front end portion m12 of the flat plate-shaped body m, and it is pushed against the stepped vertical surface 822 of the side ditches 8, which causes damage to the stepped vertical surface 82. In contrast, this anti-theft drain cover A, even in existing drainage ditches 8 without a receiving frame 9 as shown in Figure 12, increases the area of ​​the outer surface 621f of the sub-part of the plate against the vertical step surface 822 of the drainage ditches 8 by the extension of the extruded plate 6, and fixes and holds the drain cover 1 to the drainage ditches 8 with the force of surface contact with the drainage ditches 8, so that the drainage ditches 8 are not damaged. Figures 1 to 11 show a ditch cover A with an anti-theft device where the extruded plate 6 is pressed against a receiving frame 9. However, it is not limited to this configuration; it can also be used in configurations such as those shown in Figures 12 and 13, where the extruded plate 6 is directly pressed against a stepped vertical surface 822 of a side ditch 8. Regardless of whether or not there is a receiving frame 9, this ditch cover A with an anti-theft device is an excellent product that can be stably fixed and held in place on the side ditch 8 for a long period of time.

[0032] Furthermore, if the receiving frame 9 is omitted, only the side ditch 8 will form a stepped vertical surface 822. However, if a curved shape 621R is provided on the outer protruding end portion 621 of the plate sub-part 62 as shown in Figure 13, damage to the stepped vertical surface 822 can be more completely prevented, even if there is movement such as the rotation of the plate sub-part 62 from Figure 7 to Figure 8 as the extruded plate 6 advances.

[0033] Furthermore, the main plate portion 61 and the sub-plate portion 62 protrude into the gap α between the gutter cover 1 that covers the gutter 8 and the vertical portion 92 of the receiving frame, in a manner that is visible when tightening the nuts 7. Therefore, the worker can adjust the tightness of the nuts 7 located near the four corners of the gutter cover 1 to balance the gap α that appears on the road surface. Thus, the worker can neatly and straightly install multiple gutter covers A with anti-theft devices that cover the upper opening of the gutter 8 without much effort or labor. The gutter covers A with anti-theft devices are also aesthetically pleasing. Furthermore, the above process is extremely simple, consisting only of setting the extrusion plate 6, attaching the washer SW and nut 7 to the bolt shaft 5, and tightening the nut 7 (Figures 6-8). The tightening of the nut 7 reduces the angle θ1 and is a quick process. In particular, as shown in Figure 6, if the main part of the plate 61 is placed against the vertical surface 4g and tilted downwards toward the side support material 12, and the protruding part 621 of the sub-part of the plate 62 is placed against the vertical part 92 of the receiving frame, then all that remains is to tighten the nut 7, making the process very easy.

[0034] In addition, by providing an anti-theft device J consisting of a relatively small base plate 2, bolt shaft 5, extruded plate 6, and nut 7, and forming a notch 121 in the side support material 12, a simple configuration is achieved that provides an anti-theft function and is economically superior as a trench cover A with an anti-theft device. Furthermore, the groove cover 1, which integrates the base plate 2 with the bolt shaft 5, can be housed within the outer dimensions of the groove cover 1, thus avoiding any hindrance to storage or transportation. And when transporting it to the site, only the small plate-shaped extruded plate 6, nut 7, and washer SW need to be brought along with it, making storage and transport extremely easy. The anti-theft device-equipped drain cover A, which adds an anti-theft function to the drain cover, can achieve the objective of this invention with a small number of parts, a smaller component configuration than conventional designs, and at an unprecedentedly low cost. Thus, this manhole cover A with an anti-theft device exhibits the numerous excellent effects described above and is extremely beneficial.

[0035] Furthermore, this invention is not limited to the embodiments shown above, and can be modified in various ways within the scope of this invention depending on the purpose and application. The shape, size, number, material, etc. of the ditch cover 1, base plate 2, bolt shaft 5, extruded plate 6, nut 7, side ditch 8, receiving frame 9, etc. can be appropriately selected according to the application. Although this embodiment is applied to a side ditch, it can also be applied to catch basins, etc. [Explanation of Symbols]

[0036] 1 Ditch cover, 11 Main member, 12 Side bracing, 121 Notch, 2 Base plate, 3 Flat plate section, 4 Vertical plate section, 4g Vertical surface, 41 Inclined plate section, 42 Vertical section, 5 Bolt shaft, 6 Extruded plate, 60 Through hole, 61 Main plate section, 611 Rear end section, 61R Rounded, 62 Sub-plate section, 621 Protruding end section, 621R Rounded, 7 Nut, A Ditch cover with anti-theft device, F Bent section, S Gap (slit)

Claims

1. A metal plate-shaped groove cover is formed by arranging multiple strip-shaped main members upright in the width direction with gaps between them, connecting members perpendicular to each other to form a grid, and closing both sides of the main members with side members to form a rectangular shape in plan view. A base plate body is fixed to the part of the main member near the side support material, comprising a flat plate portion that is horizontally arranged in the lower edge area between adjacent main members of the groove cover, and a vertical plate portion that extends vertically upward or inclined backward from a bent portion that bends at its rear end, A bolt shaft is fixed upright to the central area of ​​the upper surface of the flat plate portion, An extruded plate having a through-hole in the central area of ​​the main part of the plate into which the bolt shaft is loosely inserted, and a secondary part of the plate extending from the main part of the plate which bends in an L-shape when viewed from the side, A nut is screwed onto the tip of the bolt shaft, which is loosely inserted into the through hole of the extruded plate, It comprises a notch formed by cutting out the lower edge portion of the side support material near the base plate, A ditch cover with an anti-theft device, characterized in that, in the initial stages of screwing and tightening the nut onto the bolt shaft, the rear end portion of the main part of the plate contacts the vertical surface of the vertical plate portion, and in a side view with the ditch cover installed in the gutter, the main part of the plate slopes downward toward the nearby side backing material, and the sub-part of the plate extending from the front end portion of the main part of the plate is positioned upward through the notch, and as the tightening of the nut progresses, the rear end portion slides downward along the vertical surface, reducing the downward slope angle of the main part of the plate, and pushing the main part of the plate forward.

2. The anti-theft device for a trench cover according to claim 1, wherein the base plate, the bolt shaft, the extrusion plate, and the nut are provided near the four corners of the rectangular trench cover in plan view.

3. The groove cover with an anti-theft device according to claim 1 or 2, wherein the vertical plate portion is, in a side view, bent at an obtuse angle with respect to the flat plate portion from the rear end of the flat plate portion and extends in an upward sloping manner toward the rear, and a bend boundary portion is provided at the upper end of the inclined plate portion, and a vertical portion with a vertical surface extends from there.

4. The groove cover with an anti-theft device according to claim 3, wherein, in a side view of the extruded plate, a curved shape is formed in the rear end portion on the lower side of the main part of the plate that corresponds to the vertical surface of the vertical plate portion.

5. The groove cover with an anti-theft device according to claim 4, wherein the outer protruding end portion of the plate sub-part has a curved shape formed in a side view.

Images