JP2678352B2 - Locking device for manhole cover - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a locking device for a manhole inner lid installed in a manhole of an underground gallery in which a distribution line or the like is laid.

[0002]

2. Description of the Related Art A manhole cover installed in a manhole in an underground mine where distribution lines are laid is a safety measure to prevent people or objects from falling from the manhole opening when the manhole cover is opened. , Or as a watertight measure to prevent rainwater from flowing into the underground tunnel.

As a lock device for such a manhole cover, a device shown in FIG. 9 has been conventionally known. In the locking device shown in the figure, a screw hole 102 is provided at the center of a horizontal rod 100 having protrusions 101, 101 at both ends.
The lower end of the tension bolt 103 screwed into the screw hole 102 is mounted on the manhole-side inner lid receiving portion 301, and the bolt receiving portion 202 is provided in the central portion of the manhole inner lid 200.
The manhole inner lid 200 is pressed downward and the reaction is made to the engaging groove portions 302, 30 on the manhole side.
The projecting portions 101, 101 fitted in 2 are engaged with the upper wall surfaces 303, 303 of the engaging groove portions 302, 302. In FIG. 9, 400 is a manhole outer lid, 304 is a manhole side outer lid receiving portion, and B is a lid receiving portion including an outer lid receiving portion 304 and an inner lid receiving portion 301.

Further, Japanese Utility Model Laid-Open No. 62-7445 discloses that
As another manhole inner lid locking device, there are three engagement links that are engaged with and disengaged from the inner lid receiving portion 301 described in FIG. It is described that a lock mechanism using an operation bolt for operating is provided, and the head of the operation bolt adopts an irregular shape other than a general hexagonal shape.

[0005]

However, the locking device for the manhole inner lid described with reference to FIG. 9 can be loosened by using a generally used tool such as a wrench or a spanner as the tension bolt 103. Since a thing is used, the horizontal rod 100 can be easily removed by loosening the tension bolt 103 of the manhole outer cover 400 only by opening it. In addition, even if the tension bolt 103 that requires a special tool to loosen the tension bolt 103 is used, the tension bolt 10
If the horizontal rod 100 itself is hit hard with a hammer or the like without loosening 3, the horizontal rod 100 will be deformed and the protruding portions 101, 101
May be disengaged from the engaging groove portions 302, 302, so that the horizontal rod 100 can be removed in that manner.

Therefore, the locking device for the manhole cover explained with reference to FIG. 9 is not so highly evaluated from the viewpoint of preventing the terrorist act performed by opening the manhole cover 200.

On the other hand, the locking device for the manhole inner lid disclosed in Japanese Utility Model Laid-Open No. 62-7445 is provided with a complicated lock mechanism using an engaging link and an operating bolt, and the manhole inner lid itself is operated. Since the locking device itself is expensive because it uses a bolt that can be loosened only with a special tool, it is necessary to replace the existing manhole cover with a manhole cover equipped with such a locking device. Therefore, it is economically disadvantageous.

The present invention has been made in view of the above circumstances, and has a function of ensuring the safety of the manhole cover without changing the shape or structure of the manhole cover or the engaging groove portion on the manhole side. It is an object of the present invention to provide a lock device for a manhole inner lid, which is capable of reliably exerting a rainwater inflow prevention function and is particularly useful as a measure against terrorism.

Further, although the present invention uses a horizontal rod, when the horizontal rod is hit with a hammer or the like, the horizontal rod is easily deformed so that the manhole cover can be removed. It is an object of the present invention to provide a lock device for a manhole inner lid, which is particularly useful as a terrorism prevention measure that can prevent such a situation that it will end up.

[0010]

The invention according to claim 1 is
At the end of the horizontal rod provided above the manhole inner cover, a protrusion and a screw hole that can be fitted into the engagement groove provided on the manhole side are provided, and the manhole inner cover is lowered to the screw hole. It is possible to screw a projecting bolt that presses against the upper surface of the engaging groove portion with the projecting portion that has been fitted into the engaging groove portion by its reaction.

With this construction, when the tension bolt is screwed into the screw hole of the horizontal rod and tightened, the protrusion of the horizontal rod moves toward the manhole side due to the reaction when the tension bolt pushes the manhole cover downward. It engages with the provided engagement groove portion and, at the same time, exhibits a safety ensuring function and a rainwater inflow preventing function in which the manhole cover is pressed downward. Further, since the above-mentioned tension bolt is screwed into the screw hole provided at the end portion of the horizontal rod, the tension bolt and the protrusion engaging with the engagement groove portion on the manhole side are the end portions of the horizontal rod. Adjacent to each other in the vicinity. Therefore, even if the horizontal rod is hit with a hammer or the like, the protruding portion is unlikely to separate from the engagement groove portion on the manhole side.

In the lock device having the above structure, as in the invention according to claim 2, the contour line of the head portion of the bulging bolt in plan view is formed by a plurality of arc lines and a plurality of straight lines. Desirably, if you do so, it is not possible to loosen the tension bolts only by using commonly used tools, and a special tool is required to loosen the tension bolts, so have a dedicated tool No one can loosen the tension bolts and remove the horizontal bar. The same effect is achieved in the invention according to claim 3. In addition, in Claim 3, "the shape of the head portion of the strut bolt is different" means that the shape of the head portion of the strut bolt is not a regular polygon such as a regular hexagon or a regular square, and That is, it is not an elliptical shape.

According to the invention as described in claim 4, such an action is such that the small diameter hole portion is formed at the end of the horizontal rod and the large diameter hole portion communicates with the small diameter hole portion via the stepped portion. Are provided concentrically, the small diameter hole portion is a screw hole, and the distance between the head of the tension bolt screwed into the screw hole and the peripheral wall surface of the large diameter hole portion is If it is large enough to fit the bolt operation tool that is fitted to the head of the tension bolt,
It is even more prominent.

According to a fifth aspect of the present invention, the lock device having the structure described in the fourth aspect is provided with a tubular portion that can be fitted into the large diameter hole portion and a collar provided at one end portion of the tubular portion. If a cap made of synthetic resin having a portion is provided, it is possible to fit the tubular portion of the cap into the large diameter hole portion and close the large diameter hole portion with the collar portion. The cap can prevent sand and sand from entering the large diameter hole.
Therefore, when loosening the bulging bolt when the loosening of the bulging bolt is clogged with soil or sand in the gap between the head of the bulging bolt screwed into the screw hole of the horizontal rod and the peripheral wall surface of the large diameter hole, the bolt operation is a special tool. Tool cannot be fitted into the head of the tension bolt,
Such a situation can be prevented.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a partially cutaway plan view of a lock device A according to an embodiment of the present invention, FIG. 2 (a).
2B is a front view of the tension bolt 3 used in the lock device A, FIG. 2B is a plan view of the tension bolt 3, and FIG. 3 is a perspective view of the cap 5 used in the lock device A seen from diagonally below. It is a figure. Further, FIG. 4 shows a partially broken state of the lock device A, FIG. 5 and FIG. 6 show a partially broken main part of the lock device A in the used state, and FIG. The other main part in use is partially cut away. FIG. 8 is an explanatory view showing the shape of the engagement groove portion 302 on the manhole side.

The lock device A includes a horizontal rod 1 shown in FIG. 1, a tension bolt 3 shown in FIG. 2, and a cap 5 shown in FIG.

The horizontal rod 1 has a horizontally long rod 11 formed in a cross shape in cross section by a vertical rib and a horizontal rib, and a hollow cylindrical portion 12 provided at the center of the rod 11 and having an open lower surface. It has and both ends of the rod 11, that is, the horizontal bar 1
At both ends of the cylindrical parts 13, 13 and those cylindrical parts 13,
It is provided with projecting portions 14 and 14 projecting outward from 13. This horizontal rod 1 is made of casting and is integrally formed.
Since 1 has a cruciform cross section, it has an extremely large bending strength and is not easily deformed unless it is hit with a hammer or the like.

As shown in FIG. 7, the hollow cylindrical portion 12 is provided with a recess 15 capable of receiving the bolt receiving portion 202 provided in the central portion of the existing manhole cover 200. As shown in FIG. 5 and FIG. 6, the small diameter hole portion 16 and the small diameter hole portion 1 are formed in the cylindrical portion 13 at each end of the horizontal rod 1.
6, a large diameter hole portion 18 communicating with a stepped portion 17 is concentrically provided, and the small diameter hole portion 16 serves as a screw hole 19. An annular rib 21 is provided on the upper end surface of the cylindrical portion 13 as shown in FIGS. 5 and 6.

As shown in FIG. 2, the tension bolt 3 has a shaft portion 31 having a male screw and a head portion 32 provided at one end portion of the shaft portion 31, which can be seen in FIG. like,
The contour line of the head 32 in a plan view is formed by two long and short arc lines 33, 34 located on the opposite side and two straight lines 35, 36 extending between the ends of the arc lines 33, 34. Since the head portion 32 of the strut bolt 3 has an extremely special shape as described above, a hexagonal headed bolt, a hexagonal headed bolt, and an elliptical headed bolt that are generally used, etc. It cannot be tightened or loosened with a tool such as a general wrench or wrench that is used when turning the bolt, and the wrench-type bolt operating tool 6 (see FIG. 6) dedicated to the tension bolt 3 is used. It can only be tightened and loosened.

As shown in FIG. 3, the cap 5 is provided on the cylindrical portion 51 which can be fitted into the large diameter hole portion 18 formed in the cylindrical portion 5 of the horizontal rod 1 and one end portion of the cylindrical portion 51. Mitsuba 5
2 and the edge piece portion 53 is provided downward on the outer periphery of the collar portion 52. The cap 5 is made of a synthetic resin such as polyvinyl chloride resin, and has a cylindrical shape.
A split groove 54 is formed at two locations in the circumferential direction of 1 so that the tubular portion 51 can be elastically expanded and contracted without breaking the tubular shape.

A lid receiving frame B shown in FIG. 4 is provided above the manhole. The lid receiving frame B is an outer lid receiving portion 30 to which the manhole outer lid 400 described in the conventional example is mounted.
4 and the inner lid receiving portion 30 on which the manhole inner lid 200 is mounted.
1, the pair of engaging groove portions 302, 302
Are provided at opposed positions separated by 180 degrees. As shown in FIGS. 4 to 6, these engaging groove portions 302, 302 are formed in the bulging portions 305, 305 formed on the inner surface of the lid receiving frame B. The shape of the engaging groove portion 302 is shown in FIG.
As shown in the figure, the engaging groove portion 302 has a horizontally long horizontal groove 307.
The upper end of one end of the groove is opened to form the entrance / exit 308, and the other end of the horizontal groove 307 of the engaging recess 30 is recessed upward.
9 are formed. Then, the pair of engaging groove portions 302,
302 has a point-symmetrical relationship with each other,
The protrusions 14, 14 at both ends of the horizontal rod 1 can be fitted into the engaging groove portions 302, 302.

In the above, the lid receiving frame B is the same as that shown in FIG. 9, and the manhole inner lid 200 is also the same as that explained in FIG.

Here, the bolt operating tool 6 described above is
The head 32 of the strut bolt 3 is provided with a fitting hole that can be fitted from above and can be engaged with the head 32 in the circumferential direction. Then, as shown in FIG. 5, when the shaft portion 31 of the tension bolt 3 is screwed into the screw hole 19 of the horizontal rod 1 and the head portion 32 is housed in the large diameter hole portion 18, the large head portion 32 and the large diameter hole are formed. Part 1
The distance from the peripheral wall surface of 8 is such that the bolt operating tool 6 can be inserted and the fitting hole can be fitted into the head 32 of the tension bolt 3.

Next, the use state and operation of the lock device A will be described.

The lock device A is adjusted by screwing the projecting bolt 3 into the screw hole 19 of the horizontal rod 1 so that the lower end of the projecting bolt 3 does not project too much from the cylindrical portion 13. In this state, the protrusion 14 of the horizontal rod 1 is fitted into the engagement groove 302 by utilizing the inlet / outlet 308 of the engagement groove 302 on the manhole side as shown by the arrow A in FIG.
By slightly turning, the protruding portion 14 is slid in the horizontal groove 307 of the engaging groove portion 302 as indicated by the arrow B. At this time, as shown in FIG. 7, the bolt receiving portion 202 of the manhole cover 200 is housed in the recess 15 of the hollow cylindrical portion 12 of the horizontal rod 1, so that the bolt receiving portion 202 does not interfere.

Next, the tension bolt 3 is screwed in and tightened with the dedicated bolt operating tool 6. In this way, the projecting portion 14 of the horizontal rod 1 is lifted up in the engaging groove portion 302 by the reaction when the tension bolt 3 pushes the outer peripheral portion upper surface of the manhole inner lid 200 downward, and as shown in FIG. It fits in the engaging recess 309 and engages with the upper wall surface 310 of the engaging groove 302 as shown in FIGS. 4 and 5. At the same time, the manhole inner lid 200 is pressed downward, so that the inner lid receiving portion 301
The packing P is closely attached and fixed to the manhole cover 200, and the manhole cover 200 has a safety ensuring function and a rainwater inflow preventing function. The packing P is attached to either the back surface of the manhole inner lid 200 or the upper portion of the inner lid receiving portion 301 in advance to prevent rainwater from flowing into the manhole. However, the packing P is not provided. Even if the back surface of the manhole inner lid 200 and the inner lid receiving portion 301 are in close contact with each other, rainwater inflow into the manhole can be stopped.

After tightening the tension bolts 3, as shown in FIGS. 4 and 5, the tubular portion 51 of the cap 5 is fitted into the large diameter hole portion 18 of the horizontal rod 1 and the flange portion 52 is pressed against the annular rib 21. I guess.

When the manhole inner lid 200 is fixed in this manner, the tension bolts 3 are adjacent to each other at a position close to the protrusion 14 engaged with the engagement groove 302 on the manhole side, and they are adjacent to each other. Since it is provided at the end portion of the horizontal rod 1, even if the horizontal rod 1 is strongly hit with a hammer or the like, it is not easy for the protruding portion 14 to be disengaged from the engagement groove portion 302.

Further, as described above, since the projecting bolt 3 can be loosened only by the dedicated bolt operating tool 6, a person who does not have such a tool 6 can loosen the projecting bolt 3 and level it. The rod 1 cannot be removed. Moreover, since the head portion 32 of the tension bolt 3 is housed in the large diameter hole portion 18 of the horizontal rod 1, it is not possible to forcibly loosen the tension bolt 3 using pliers or pliers.

When it is desired to open the manhole cover 200,
Dedicated bolt operation tool 6 after removing the cap 5
Loosen the tension bolts 3 by using, rotate the horizontal rod 1 in the opposite direction a little, and then pull it up to remove the horizontal rod 1. In this case, since the cap 5 closes the large-diameter hole 18 before removing the horizontal rod 1, the large-diameter hole 18 is clogged with soil or sand, and the dedicated bolt operating tool 6 is used for the large-diameter hole 18. There is no risk of a situation in which the plug cannot be inserted into the portion 18.

In the lock device A described above, the head portion 32 of the tension bolt 3 has the shape shown in FIG. 2B, but the head portion 32 may have another shape. In short, the head 32 has a contour line in plan view,
The locking device using such a tension bolt is included in the invention according to claim 2 as long as it is formed by a plurality of arc lines and a plurality of straight lines. Further, the tension bolt may have a head of other shape and can be fitted only by a dedicated bolt operating tool. A locking device using such tension bolt is claimed. It is included in the invention according to item 3.

[0032]

According to the first aspect of the present invention, there is provided a protrusion engaged with the engagement groove on the manhole side, and a tension bolt for engaging the protrusion with the upper wall surface of the engagement groove. Are adjacent to each other in the vicinity of the end portions of the horizontal rods, so that even if the horizontal rods are hit with a hammer or the like, the protruding portion does not easily come off from the engagement groove portion on the manhole side. It is effective as a measure against terrorism.

According to the inventions of claims 2 and 3,
Those who do not have a special tool can not remove the horizontal rod by loosening the tension bolt, so this is also effective as a terrorism prevention measure.

According to the fourth aspect of the present invention, the head of the tension bolt is set to fit in the large diameter hole of the horizontal rod when the manhole cover is locked.
A person who does not have a bolt operation tool that can be fitted into the gap between the head of the tension bolt screwed into the screw hole and the peripheral wall surface of the large diameter hole cannot loosen the tension bolt. Therefore, the speciality of the bolt operation tool is increased, which is extremely useful as a terrorism prevention measure.

According to the invention of claim 5, it is possible to prevent the situation where the large diameter hole portion is clogged with soil or sand and the bulging bolt cannot be loosened even by using a bolt operating tool which is its dedicated tool. Since the manhole cover can be opened as necessary, the tension bolt cannot be loosened.

Then, claim 1, claim 2, claim 3,
Since the invention according to claim 4 or claim 5 can configure the locking device for the manhole inner cover without changing the shape or structure of the existing manhole engaging groove portion or manhole inner cover. , It has been adopted as an urgent terrorism prevention measure, and very good results have been obtained.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view of a lock device according to an embodiment of the present invention.

FIG. 2A is a front view of a tension bolt. (B)
[Fig. 4] is a plan view of a tension bolt.

FIG. 3 is a perspective view of the cap as viewed from diagonally below.

FIG. 4 is a side view showing a partially broken state of a lock device in use.

FIG. 5 is a side view showing a partial cutaway of a main part of the lock device in use when the tension bolt is tightened.

FIG. 6 is a side view showing a part of a main part of the lock device in use when the tension bolt is loose.

FIG. 7 is a side view showing a partial cutaway of another main part of the lock device in use when the tension bolt is loose.

FIG. 8 is an explanatory view showing a shape of an engaging groove portion.

FIG. 9 is a side view showing a partially broken state of a conventional lock device in use.

[Explanation of symbols]

 A Lock device 1 Horizontal rod 3 Stretch bolt 5 Cap 6 Bolt operating tool 14 Projection portion 16 Small diameter hole portion 17 Stepped portion 18 Large diameter hole portion 19 Screw hole 32 Head portion 33, 34 Arc line 35, 36 Straight line 51 Cylindrical part 52 Collar part 200 Manhole inner lid 302 Engagement groove part 310 Upper wall surface of engagement groove part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiari Asai 3-3-22 Nakanoshima, Kita-ku, Osaka-shi, Osaka Kansai Electric Power Co., Inc. (72) Inventor Takashi Tetsuhashi 2-chome, Higashitenma, Kita-ku, Osaka No. 3-21 Nichido Electric Works Co., Ltd. (56) References Actually open 4-22538 (JP, U) Actually open 49-81358 (JP, U)

Claims (5)

(57) [Claims] 1. A projecting portion and a screw hole which can be fitted into an engaging groove portion provided on the manhole side are provided at an end portion of a horizontal rod provided above the manhole inner cover, and the screw hole has a screw hole, It is possible to screw a tension bolt that pushes the manhole cover downward and engages the protruding portion fitted in the engaging groove portion with the upper wall surface of the engaging groove portion by its reaction. Locking device for manhole cover. 2. The plan view contour line of the head of the tension bolt is
The manhole cover locking device according to claim 1, wherein the lock device is formed of a plurality of arc lines and a plurality of straight lines. 3. The locking device for a manhole inner lid according to claim 1, wherein the shape of the head of the tension bolt is different. 4. A small-diameter hole portion and a large-diameter hole portion communicating with the small-diameter hole portion via a stepped portion are concentrically provided at the end of the horizontal rod, and the small-diameter hole portion is provided. As well as being a screw hole,
The distance between the head of the bulging bolt screwed into the screw hole and the peripheral wall surface of the large diameter hole is large enough to fit the bolt operating tool fitted in the head of the bulging bolt. The locking device for the manhole inner lid according to any one of claims 1, 2, and 3. 5. The manhole lid lock according to claim 4, further comprising a synthetic resin cap having a tubular portion that can be fitted into the large diameter hole portion and a flange portion provided at one end of the tubular portion. apparatus.