JP4882104B2 - Anti-rotation device and method for attaching / detaching underground fire hydrant using the same - Google Patents

Description

  The present invention relates to a rotation prevention device for preventing one of the bolts and nuts from rotating when one of them is loosened. In particular, the present invention relates to a travel prevention tool used when replacing a fire hydrant.

  When one of the bolts or nuts is loosened, the other may not be able to be rotated and removed. In such a case, conventionally, both the bolt and the nut are gripped by a wrench or the like, and one is held so as not to rotate, and the other is rotated. For example, when working alone, the left hand grasped the bolt with a wrench so as not to rotate, and the right hand loosened the nut with a wrench.

  By the way, when the place to work is large, as mentioned above, both a bolt and a nut can be grasped with a wrench, and one can be loosened. However, when the working place is small, it is difficult to hold both the bolt and the nut with a wrench.

For example, an underground fire hydrant is placed in a fire hydrant box. This underground fire hydrant is placed on a repair valve connected to a vertical pipe branched from a distribution pipe, and the flanges of the fire hydrant and the repair valve are fixed by bolts and nuts.
When the hydrant is old and replaced with a new hydrant, or when replacing the old hydrant with a ball hydrant, it is necessary to remove the bolts and nuts that secure the repair valve and hydrant. is there. This work needs to be done in the fire hydrant box.

  However, the fire hydrant box is narrow, and in order to remove the bolts and nuts, it is necessary to pull the hand into the fire hydrant box and grasp the bolts and nuts on the lower side of the flange with a wrench to prevent rotation. In a narrow fire hydrant box, it is difficult to prevent rotation by gripping one of the bolts or nuts with a wrench from the underside of the flange, and it takes considerable time to remove the bolts and nuts.

  The problem to be solved by the present invention is to provide an anti-rotation device that prevents the other of the bolts and nuts from rotating when one of them is loosened.

The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is used to replace an underground fire hydrant provided in a fire hydrant box, and a bolt head or a nut cannot be rotated. And a magnet for fixing the body to a body to be attached to which the bolt or nut is provided. Projecting upward and provided with a locking piece along the end of the mounted body to which the bolt or nut is attached, and the receiving hole is a substantially contactable surface of a pair of parallel hexagon bolts or nuts. The bottom is closed in whole or in part, and the locking piece has an arcuate surface along the edge of the flange of the vertical pipe branched from the water distribution pipe or the flange of the repair valve. The main body has a string It is co-rotation preventing device, characterized in that connection that one end of the body are connected is provided.

The invention according to claim 2, wherein the receiving hole is a co-rotation preventing device according to claim 1, characterized in that it is formed open to the top and one side of the body.

According to a third aspect of the present invention, there is provided the anti-rotation device according to the second aspect, wherein projecting portions are formed opposite to each other at both open end portions opened on the one side surface of the accommodation hole. It is.

The invention according to claim 4, the upper end of the accommodating hole, one of the claims 1 to second accommodation hole washer is accommodated, characterized in that it is formed by widened to claim 3 It is a rotation prevention tool as described in Crab.

The invention according to claim 5 is characterized in that the accommodation hole is capable of accommodating the nut in a non-rotatable manner, and a notch into which a tip end portion of the bolt is inserted is formed at the bottom of the accommodation hole. The rotation prevention tool according to any one of claims 2 to 4 .

The invention according to claim 6 is the anti-rotation device according to claim 5 , wherein the notch is formed to open to one side surface of the main body.

Further, the invention according to claim 7 is a method of removing an underground fire hydrant arranged in a fire hydrant box and attaching a new fire hydrant or reattaching the removed fire hydrant after in-pipe inspection, fire hydrant is placed placed the lower flange to the upper flange of repair valve, wherein is fixed is a nut tightened from below the upper flange on the top of the hexagonal bolt passing through the flanges upward from claim 1 A step of attaching the swivel prevention device according to any one of claims 6 to the head of the bolt, a step of loosening the nut and removing it from the bolt, and a base-type fire hydrant with the bolt remaining. Removing from the repair valve; placing a new fire hydrant or the removed fire hydrant on the repair valve so that the bolt is inserted into the flange; and A removable method of underground hydrant which comprises the steps of: a serial bolt screwed nuts.

  According to the rotation prevention tool of the present invention, when one of the bolts or nuts is loosened, the other rotation can be prevented.

Hereinafter, an embodiment of the anti-rotation device of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of the anti-rotation device of the present invention. 2 is a cross-sectional view taken along the line XX in FIG. 1, and FIG. 3 is a cross-sectional view taken along the line YY in FIG.

  The main body 1 of the anti-rotation device of the present embodiment is a substantially rectangular parallelepiped block, and the left and right front and rear corners are cut away in FIG. Specifically, the left end portion of the main body 1 is formed in an isosceles trapezoid shape that is reduced in width toward the left side. In this embodiment, the main body 1 is made of stainless steel, but it may be a casting or a synthetic resin molded product.

  The main body 1 is formed with a receiving hole 3 into which the head of the hexagon bolt can be fitted. The accommodation hole 3 of the present embodiment has a rectangular shape in plan view, and is formed to open to the upper surface and the left side surface of the main body 1. Further, the bottom 5 of the accommodation hole 3 is closed.

  Projecting portions 7, 7 projecting inward in the front-rear direction are formed at both ends of the opening of the accommodation hole 3 that opens to the left side of the main body 1. That is, projecting portions 7 and 7 are formed so as to project opposite to each other at both ends of the opening of the receiving hole 3 that opens to the left side of the main body 1, and the opening on the left side of the main body 1 is slightly narrowed. . In the present embodiment, the protruding portion 7 has a substantially triangular shape in plan view, its left side surface is flush with the left side surface of the main body 1, and its right side surface is formed in an arc shape.

4A and 4B are diagrams showing hexagon bolts, where FIG. 4A is a plan view and FIG. 4B is a front view with a part omitted.
The rotation prevention tool of a present Example respond | corresponds to conventionally well-known various hexagon bolts. The size of the hexagon bolt is not particularly limited, but an M16 bolt is usually used in an underground fire hydrant described later.

  Referring to FIG. 4, based on FIGS. 1 to 3, the front-rear width (the distance between the front wall surface 9 and the rear wall surface 11) of the accommodation hole 3 corresponds to the distance a between the opposing surfaces of the hexagon bolt. ing. That is, the front-rear width of the accommodation hole 3 corresponds to the distance a between a pair of parallel surfaces of the hexagon bolt. The depth of the accommodation hole 3 corresponds to the thickness b of the bolt head.

FIG. 5 is a perspective view showing a state in which the head of the hexagon bolt is fitted in the accommodation hole of the main body.
When the head H of the hexagon bolt B is fitted into the housing hole 3 of the main body 1, a pair of parallel surfaces of the head H abut against the front wall surface 9 and the rear wall surface 11 of the housing hole 3, respectively. One apex abuts against the wall surface 13. Then, another vertex is arranged to protrude outward (left side) from the opening on the left side surface of the main body 1. Further, in a state where the head H of the hexagon bolt B is fitted in the accommodation hole 3, the protrusions 7 and 7 abut or approach the corners of the head H of the hexagon bolt B.
Thus, in a state where the head H of the hexagon bolt B is fitted in the accommodation hole 3, the hexagon bolt B is not rotatable with respect to the main body 1. Even if the pair of parallel surfaces and one apex of the head H of the hexagon bolt B do not contact the respective wall surfaces 9, 11, 13 of the receiving hole 3, the head of the hexagon bolt B can be used when loosening the nut. It suffices if the portion H cannot be rotated with respect to the main body 1.

In the present embodiment, the upper end of the accommodation hole 3 is widened, and a shallow recess (second accommodation hole) 15 is formed on the upper surface of the main body 1. A washer can be accommodated in the recess 15.
The recess 15 is formed in a U-shape that opens to the left, with the left end being a square shape and the right end being a semicircular shape. The outer diameter of the right end of the recess 15 corresponds to the outer diameter of the washer. Further, the depth of the recess 15 corresponds to the thickness of the washer.
As described above, the main body 1 is formed with a stepped hole including the accommodation hole 3 and the recess 15.

  The main body 1 is provided with a magnet 17. In the present embodiment, magnets 17 and 17 are provided on both front and rear sides of the accommodation hole 3. The magnet 17 according to the present embodiment has a columnar shape and is provided in the main body 1 in a state of being accommodated in a cylindrical case 19. The case 19 includes a cylindrical inner case 20 and an outer case 21, and the inner case 20 is fitted inside the outer case 21, and the magnet 17 is fitted into the inner case 20.

In the present embodiment, the magnet 17 is provided so as to be fitted into the hole 22 formed in the main body 1 with its magnetized surface (magnetic pole surface) facing upward. That is, the magnet 17 is arrange | positioned at the main body 1 so that the axial direction may follow an up-down direction. The magnet 17 provided on the main body 1 has a magnetized surface that is substantially flush with the upper surface of the main body 1 and is exposed on the upper surface of the main body 1.
In the present embodiment, the magnet 17 is housed in the case 19 and fitted into the main body 1, but the magnet 17 may be directly fitted into the hole 22 of the main body 1. At this time, the magnet 17 is fixed to the main body 1 with an adhesive or is fixed by welding.

  A locking piece 23 is formed at the right end of the main body 1 so as to protrude vertically upward. The locking piece 23 of the present embodiment has a left side surface 25 formed in an arc shape in plan view. Specifically, the left side surface 25 of the locking piece 23 is formed in an arcuate surface corresponding to the outer diameter of the upper flange 55 of the repair valve 47 described later.

  Further, on the right side surface of the main body 1, a connection portion 27 to which one end portion of a string-like body (including a string, a chain, a rope, and a wire) is connected is provided. In the present embodiment, both open ends of the substantially U-shaped connecting portion 27 are fixed to the central portion of the right side surface of the main body 1 and provided integrally.

  The rotation prevention tool of the present embodiment having such a configuration can prevent the rotation of the bolt when the nut is loosened with respect to the bolt. In order to use the anti-rotation device of the present embodiment, first, the head of the bolt is fitted into the receiving hole 3 of the main body 1, and the main body 1 is attached to the mounted body provided with bolts and nuts. At this time, the main body 1 is provided with the magnets 17 and 17 so that the main body 1 may be magnetically attached to the attached body. Then, the nut is rotated with respect to the bolt with a wrench or the like, and the nut is loosened and removed from the bolt. Since the head of the bolt is fitted in the receiving hole 3 of the main body 1 so as not to rotate, and the main body 1 is fixed to the mounted body with magnets 17 and 17, the nut is rotated with respect to the bolt. However, the bolts will not go around.

As described above, the anti-rotation device of the present embodiment is used when loosening the nut with respect to the bolt, but is particularly preferably used when replacing the fire hydrant.
The fire hydrant may be replaced due to aging, or may be replaced from the old model to the new model. In this replacement, the anti-rotation device of this embodiment is preferably used. In addition, the fire hydrant after replacement may be the same type or different from the fire hydrant before replacement.

  Hereinafter, a method for replacing the underground fire hydrant using the anti-rotation tool of the present embodiment will be described.

  FIG. 6 is a schematic view showing a state in which the anti-rotation device of FIG. 1 is attached to a bolt that fixes a repair valve and an existing underground fire hydrant. FIG. 7 is a partially enlarged sectional view of FIG. 6 and shows a state in which the nut is removed.

  As shown in FIG. 6, the underground fire hydrant 41 is provided via a repair valve 47 at the upper end of a vertical pipe 45 branched vertically upward with respect to the water distribution pipe 43 buried underground, and is usually about 100 m. It is installed in the fire hydrant box 49 at intervals.

  The repair valve 47 is, for example, a ball-type repair valve. A pipe line 51a is provided through the valve box 51 in the vertical direction, and a ball-shaped valve element 53 is rotatably disposed in the pipe line. . Further, flanges 55 and 57 are formed at the upper and lower ends of the valve box 51 of the repair valve 47, and the lower flange 57 is fixed to the flange 59 at the upper end of the vertical tube 45 by bolts and nuts 61. ing.

  The existing underground fire hydrant 41 has a flange 65 formed at the lower end of the valve box 63. The fire hydrant 41 is placed on the repair valve 47, and the flange 65 of the fire hydrant 41 and the upper flange 55 of the repair valve 47 are fixed by bolts 67 and nuts 69.

The upper flange 55 of the repair valve 47 and the flange 65 of the fire hydrant 41 have the same diameter, and through holes 71 and 73 are formed in the flanges 55 and 65 at four equal intervals in the circumferential direction, respectively.
Then, in a state where the upper flange 55 of the repair valve 47 and the flange 65 of the fire hydrant 41 are overlapped and the through holes 71 and 73 are arranged coaxially, the bolt 67 is inserted from below, and the tip of the bolt 67 is inserted. A nut 69 is screwed in and the fire hydrant 41 is fixed to the repair valve 47. At this time, washers 75 and 77 are interposed on both the head 68 side and the nut 69 side of the bolt 67.

  When replacing the existing non-ball type fire hydrant 41 with the ball type fire hydrant 83, first, as shown in FIG. 6, the present embodiment is implemented on the repair bolt 47 and the four bolts 67 provided on the flanges 55 and 65 of the fire hydrant 41, respectively. Attach the anti-rotation device of the example.

  Specifically, as shown in FIGS. 5 and 7, the main body 1 is covered from below so that the heads 68 of the bolts 67 are fitted into the receiving holes 3 of the main body 1. Further, the head 68 of the bolt 67 is fitted into the receiving hole 3 of the main body 1, the positioning piece 23 is positioned so as to be along the outer peripheral surface of the upper flange 55 of the repair valve 47, and the main body 1 is repaired by the magnet 17. 47 is magnetically attached to the lower surface of the upper flange 55. In the state where the rotation prevention tool is attached to the bolt 67, the washer 75 on the head 68 side of the bolt 67 is accommodated in the recess 15 of the main body 1.

  In addition, one end portion of the string-like body 79 is fixed to the connection portion 27 in advance, and the other end portion is pulled out above the fire hydrant box 49.

With the rotation prevention tool attached to the bolt 67, the nut 69 is loosened with a wrench or the like. The head 68 of the bolt 67 is non-rotatably fitted in the receiving hole 3 of the main body 1, and the main body 1 is fixed to the upper flange 55 of the repair valve 47 by the magnet 17. 67 will never go around.
Further, since the locking piece 23 of the main body 1 is arranged along the outer peripheral surface of the upper flange 55 of the repair valve 47, the main body 1 does not rotate relative to the upper flange 55 of the repair valve 47, and as a result The rotation of the bolt 67 is prevented. Thus, the bolt 67 does not rotate with the rotation of the nut 69, and the nut 69 can be easily removed.

  When the nut 69 is removed from the bolt 67, the bolt 67 is held by the main body 1 and is inserted into the flanges 55 and 65 of the repair valve 47 and the fire hydrant 41. That is, the bolt 67 does not fall even if the nut 69 is removed because the head 68 of the bolt 67 is placed on the bottom 5 of the receiving hole 3.

  FIG. 8 is a schematic view showing a state where the fire hydrant is removed from the state of FIG. 6. FIG. 9 is a partially enlarged sectional view of FIG.

After removing the nut 69 from the bolt 67, the existing fire hydrant 41 is pulled up and removed from the repair valve 47 as shown in FIG. At this time, the bolt 67 is held in the main body 1 of the anti-rotation device, and thus remains in a state of being inserted into the upper flange 55 of the repair valve 47 as shown in FIG.
A disc-shaped packing 81 with a hole in the center is provided between the repair valve 47 and the fire hydrant 41, and may be replaced when the fire hydrant 41 is removed or reused. .

  FIG. 10 is a schematic view showing a state in which a ball-type fire hydrant is attached from the state of FIG. FIG. 11 is a partially enlarged sectional view of FIG.

  Then, a ball-type fire hydrant 83 is placed on the repair valve 47. As with the fire hydrant 41, the ball-type fire hydrant 83 has a flange 87 formed at the lower end portion of the valve box 85, and through holes 89 are formed at four equal intervals in the circumferential direction. Accordingly, the bolt 67 inserted into the upper flange 55 of the repair valve 47 may be passed through the through hole 89 of the flange 87 of the ball type fire hydrant 83.

  In this way, after the ball-type fire hydrant 83 is placed on the repair valve 47, if the nut 69 is screwed into the bolt 67 via the washer 77, the ball-type fire hydrant 83 is fixed to the repair valve 47 and the replacement is completed. By the way, even when the nut 69 is screwed into the bolt 67, the bolt 67 is not rotated because it is held non-rotatably by the main body 1, and the nut 69 can be easily attached to the bolt 67.

  After the replacement, the upper surface of the locking piece 23 of the main body 1 is pushed with a bar or the like, and the main body 1 is dropped from the upper flange 55 of the repair valve 47. At this time, since the string-like body 79 is connected to the connection portion 27 of the main body 1, the main body 1 is dropped from the upper flange 55 of the repair valve 47, and then the string-like body 79 is pulled to pull the main body 1. It can be pulled up and collected.

In this way, by using the anti-rotation device of the present embodiment, the head of the bolt arranged below the flange is fixed with a wrench or the like in a narrow space such as the fire hydrant box 49. Therefore, it is possible to shorten the time required for replacement.
In addition, although the case where the existing fire hydrant 41 was replaced | exchanged for the ball-type fire hydrant 83 was demonstrated, the fire hydrant to replace | exchange is not restricted to a ball-type fire hydrant, Other types of fire hydrants may be sufficient. In some cases, the anti-rotation device of this embodiment can be used when replacing the ball-type fire hydrant with another type of fire hydrant.

  By the way, the distance between the outer peripheral surface between the upper flange 55 and the lower flange 57 in the valve box 51 of the repair valve 47 and the head 68 of the bolt 67 inserted into the upper flange 55 is short. Therefore, when the main body 1 is large, the repair valve 47 may not be attached to the valve box 51. However, the rotation prevention tool of the present embodiment has the accommodation hole 3 opened to the left side surface of the main body 1 and does not completely surround the head 68 of the bolt 67. Therefore, when the main body 1 is attached to the repair valve 47, the main body 1 does not hit the valve box 51 of the repair valve 47 and can be securely attached.

Further, the positions of the through holes 71 and 73 formed in the flanges 55 and 65 of the repair valve 47 and the fire hydrant 41 and the size of the bolt 67 are usually constant, and M16 is often used as the bolt.
Furthermore, even if the diameter of the flanges 55 and 65 of the repair valve 47 and the fire hydrant 41 changes, the distance between the outer peripheral surface and the through holes 71 and 73 does not change. Therefore, by making the arc-shaped left side surface 25 of the locking piece 23 of the main body 1 have a shape corresponding to the large-diameter flange, it is possible to cope with a small-diameter flange. Under such circumstances, the anti-rotation device of the present embodiment used for exchanging the fire hydrant is designed according to the standard, such as the position of the accommodation hole 3 of the main body 1 and the locking piece 23.

Further, in a state where the bolt 67 is attached to the upper flange 55 of the repair valve 47, the locking piece 23 may not be disposed along the outer peripheral surface of the upper flange 55 depending on the orientation of the head 68. Therefore, the left side surface 25 of the locking piece 23 is preferably formed in an arcuate surface that is slightly larger in diameter than the outer peripheral surface of the upper flange 55 of the repair valve 47.
When the direction of the bolt 67 is shifted due to the slightly larger diameter, the locking piece 23 is slightly biased with respect to the outer peripheral surface of the upper flange 55, and the bolt 67 is inserted into the receiving hole 3 of the main body 1. The head 68 is fitted.
When the nut 69 is loosened from this state, the main body 1 itself rotates around the upper flange 55 of the repair valve 47 and the locking piece 23 comes into contact with the outer peripheral surface of the upper flange 55. Thereby, similarly to the above, the main body 1 is locked to the upper flange 55, the main body 1 is not rotated with respect to the upper flange 55, and the rotation of the bolt 67 can be prevented.

  Although the method for replacing the existing fire hydrant 41 with the ball-type fire hydrant 83 has been described above, the removed fire hydrant 41 may be reattached in some cases. Specifically, once the fire hydrant 41 is removed, a device for investigating the inside of the distribution pipe 43 is attached to the repair valve 47 to investigate the inside of the water distribution pipe 43, and after the investigation is completed, the device is removed and removed again. The fire hydrant 41 may be attached to the repair valve 47.

  This investigation device includes a cylindrical member whose upper portion is closed, and a flange having the same diameter as the upper flange 55 of the repair valve 47 is formed at the lower end portion of the cylindrical member. Further, through holes are formed in the flange of the cylindrical member at four circumferentially equal intervals.

  The cylindrical member has a lower end flange overlapped with the upper flange 55 of the repair valve 47 and can be fixed with bolts and nuts in the same manner as the repair valve 47 and the fire hydrant 41 are fixed. Then, the camera cable is inserted into the cylindrical member in a watertight state from the upper wall through the packing, and the camera head provided at the tip of the camera cable is inserted into the water distribution pipe 43 through the vertical pipe 45, The situation in the tube is observed.

  In order to attach this investigation device to the repair valve 47, as described above, the existing fire hydrant 41 is once removed from the repair valve 47 using the anti-rotation tool of this embodiment. Next, the cylindrical member is placed on the repair valve 47, and the cylindrical member and the repair valve 47 are fixed with bolts 67 and nuts 69. At this time, the rotation prevention tool remains attached to the bolt 67. Then, the camera cable is inserted from the cylindrical member, and the inside of the water distribution pipe 43 is investigated. After the survey is completed, the cylindrical member is removed from the repair valve 47, the removed fire hydrant 41 is attached to the repair valve 47 again, and the anti-rotation tool may be collected.

  Thus, it is possible to use the anti-rotation tool of the present embodiment for a series of operations including the removal of the fire hydrant 41, the attachment and removal of the cylindrical member of the investigation device, and the attachment of the fire hydrant 41. In addition, as an investigation apparatus, there exists an apparatus shown by Japanese Patent Application No. 2004-297392. However, the investigation device is not limited to the one in which the camera cable is inserted into the cylindrical member, but includes one in which a bar is inserted into the cylindrical member.

  The rotation prevention tool of the present embodiment can prevent the rotation of the bolt when the bolt head is fitted into the receiving hole 3 of the main body 1 and the nut is rotated with respect to the bolt. Due to this deformation, it is possible to prevent the nut from rotating when the bolt is rotated relative to the nut.

Hereinafter, the modification of the rotation prevention tool of this invention is demonstrated.
In addition, the rotation prevention tool of this modification is the structure similar to the rotation prevention tool of the said Example fundamentally. Therefore, below, it demonstrates centering around a different part of both, and attaches | subjects and demonstrates the same code | symbol to a corresponding location.

12 and 13 are views showing a modification of the anti-rotation device of the present invention, FIG. 12 is a perspective view, and FIG. 13 is a ZZ sectional view of FIG.
As shown in FIGS. 12 and 13, the anti-rotation device of the present modified example is notched so that the central portion of the bottom portion 5 of the receiving hole 3 opens to the left side surface of the main body 1. 91 is formed.
In other words, in the anti-rotation device of this modification, the bottom portion 5 of the accommodation hole 3 is only an edge portion to the extent that the nut N does not fall off.

Thereby, in a state where the nut N is fitted in the accommodation hole 3 of the main body 1, the tip end portion T of the bolt B <b> 2 is inserted into the notch 91 of the bottom portion 5, and the state where the main body 1 holds the nut N can be maintained. .
Further, since the notch 91 is opened to the left side surface of the main body 1, the main body 1 may be slid and accommodated when the tip T of the bolt B <b> 2 is accommodated in the notch 91.

  Thus, the rotation prevention tool of the present invention can prevent the rotation of both the bolt and the nut by changing the bottom portion 5 of the accommodation hole 3.

In this modification, the notch 91 formed in the bottom portion 5 of the accommodation hole 3 is not particularly limited as long as the tip of the bolt can enter, and may be a through hole or a recess. Thereby, in a state where the nut is fitted in the accommodation hole 3 of the main body 1, the main body 1 maintains the state where the nut is held by inserting the tip of the bolt into the notch (through hole, concave portion) 91 of the bottom portion 5. can do.
The anti-rotation device of this modification can be used for both the head of the bolt or the nut, and it is optional to attach to either.

By the way, in the said Example, although the case where a rotation prevention tool was covered on the head of a bolt from the bottom was demonstrated, it is used by putting a rotation prevention tool upside down and covering the head and nut of a bolt from the top. It is also possible to do.
For example, in FIG. 6, the interval between the upper flange 55 and the lower flange 57 of the repair valve 47 is narrow, and it is difficult to attach the anti-rotation device from the bottom to the head 68 of the bolt 67 arranged at the lower part of the upper flange 55. There is a case. In such a case, what is necessary is just to attach so that the rotation prevention tool of the said modification may cover the nut 69 arrange | positioned at the upper part of the flange 65 of the fire hydrant 41 from the top. Then, the head 68 of the bolt 67 may be rotated with a wrench or the like.
Note that the bolt 67 may be inserted from above, and even in this case, the anti-rotation device of the above-described embodiments and modifications can be used.

The rotation prevention tool of the present invention is not limited to the above embodiment, and can be changed as appropriate.
For example, in the above embodiment, the connecting portion 27 is provided on the right side surface of the main body 1, but the position thereof can be changed as appropriate. The main body 1 is not limited to the block body, and the shape and configuration thereof can be changed as appropriate as long as the main body 1 has the accommodation hole 3.

Furthermore, the bottom 5 of the accommodation hole 3 may not be integrated with the main body 1, and for example, a rectangular plate material may be fixed from the back side of the main body 1.
Moreover, although the shape of the accommodation hole 3 of the main body 1 is a quadrangular shape in plan view, the shape can be appropriately changed as long as the head portion and the nut of the bolt can be held unrotatably.
Furthermore, although the said Example demonstrated the case where the rotation prevention tool of this invention was used at the time of replacement | exchange of a fire hydrant, the use place in particular is not ask | required. In other words, if the purpose is to prevent the rotation of the bolts and nuts, the bolts and nuts can be used even when the fire hydrant is not replaced. At this time, the left side surface 25 of the locking piece 23 may be formed on a curved surface or a vertical surface along the end of the mounted body to which the bolt or nut is attached.

It is a perspective view which shows one Example of the rotation prevention tool of this invention. It is XX sectional drawing of FIG. FIG. 2 is a YY sectional view of FIG. 1. It is a figure which shows a hexagon bolt, (a) is a top view, (b) is the front view which abbreviate | omitted one part. It is a perspective view which shows the state which fitted the head of the hexagon bolt in the accommodation hole of the main body. It is the schematic which shows the state which attached the rotation prevention tool of FIG. 1 to the existing underground fire hydrant. It is a partially expanded sectional view of FIG. 6, and has shown the state which removed the nut. It is the schematic which shows the state which removed the fire hydrant from the state of FIG. It is a partially expanded sectional view of FIG. It is the schematic which shows the state which attached the ball-type fire hydrant from the state of FIG. It is a partially expanded sectional view of FIG. It is a perspective view which shows the modification of the rotation prevention tool of this invention. It is ZZ sectional drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Main body 3 Receiving hole 5 Bottom part 7 Protruding part 15 Recessed part (2nd receiving hole)
17 Magnet 23 Locking piece 27 Connection part 41 Underground fire hydrant 47 Repair valve 49 Fire hydrant box 55 Upper flange 65 Flange 67 Bolt 69 Nut 71 Through hole 73 Through hole 75 Washer 77 Washer 79 String-like body 83 Ball type fire hydrant

Claims (7)

Used to replace underground fire hydrants installed in the fire hydrant box,
A main body formed with an accommodation hole that accommodates the head of the bolt or the nut in a non-rotatable manner; and
A magnet for fixing the main body to an attached body provided with the bolt or nut ;
The main body protrudes upward and is provided with a locking piece along the end of the attached body to which a bolt or nut is attached,
The accommodation hole has a substantially rectangular shape with which a pair of parallel surfaces of a hexagon bolt or a hexagon nut can come into contact with each other, and the bottom thereof is entirely or partially closed.
The locking piece has an arcuate surface along the edge of the flange of the vertical pipe portion branched from the water distribution pipe or the flange of the repair valve,
A swivel prevention device , wherein the main body is provided with a connecting portion to which one end of a string-like body is connected . 2. The anti-rotation device according to claim 1 , wherein the accommodation hole is formed to open on an upper surface and one side surface of the main body. The rotation prevention tool according to claim 2 , wherein projecting portions are formed opposite to each other at both open end portions opened on the one side surface of the accommodation hole. The upper end of the accommodating hole, co-rotation preventing device according to claim 1, the second accommodation hole washer is accommodated, characterized in that it is formed by widened to claim 3. The accommodation hole can be accommodated so that the nut cannot rotate,
The notch into which the front-end | tip part of a volt | bolt is inserted is formed in the bottom part of the said accommodation hole. The rotation prevention tool in any one of Claim 2 to 4 characterized by the above-mentioned. The anti-rotation device according to claim 5 , wherein the notch is formed to open to one side surface of the main body. A method of removing an underground fire hydrant arranged in a fire hydrant box and attaching a new fire hydrant, or reattaching the removed fire hydrant after in-pipe inspection,
The underground fire hydrant has its lower flange placed on the upper flange of the repair valve, and is fastened with a nut to the top of the hexagon bolt that penetrates both flanges from below to above the upper flange.
Attaching the anti-rotation device according to any one of claims 1 to 6 to the head of the bolt;
Loosening the nut and removing it from the bolt;
With the bolt remaining, removing the underground fire hydrant from the repair valve;
Placing a new fire hydrant or the removed fire hydrant on a repair valve so that the bolt is inserted into the flange; and
Screwing a nut into the bolt, and a method for attaching and detaching an underground fire hydrant.

Images