JPH0660651B2 - Iron lid mounting device for iron frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Object of the Invention" (Industrial field of application) The present invention relates to a device for attaching an iron lid to an iron frame such as a manhole, which appropriately prevents illegal opening of the lid. Moreover, it is an object of the present invention to provide an iron lid attachment device for an iron frame, which is excellent in operability and can be easily operated on a large member such as an iron lid for a manhole.

(Prior Art) When a nut is screwed into a protruding bolt or when a bolt is screwed into a screw hole, it is possible to easily and securely fix the object to be joined using a monkey wrench or box wrench. it can. The reason is that the head shape of the bolt or the outer circumference of the nut is almost regular hexagon, the monkey wrench is designed so that the tool can be fitted to two parallel parallel faces, and the shape of the opening of the box wrench is also regular hexagon. It is square and has little play so that it fits into the head of a bolt or nut. This standardization makes it easy to install and remove bolts and nuts, and makes the bolts, nuts, and installation tools compatible in a basic industrial connection method called screw connection. That is, it is assumed that the bolts, nuts, and tools are compatible with each other.
In No. 82, the screw head connected to the upper end of the screw portion is formed into a truncated cone shape that gradually reduces its diameter upward, and its cross section is a regular ellipse with an extremely small difference between the major axis and the minor axis. A screw having a shape and an arcuate edge by chamfering a boundary portion between the inclined side surface and the top surface has been proposed.

Furthermore, for example, iron covers of manholes such as water and sewage, city gas, and underground power lines are usually provided on the ground surface, but on the road or pavement, so as not to obstruct traffic,
The top surface of the iron lid is flush with the road surface. That is, when tightening the iron lid with bolts or nuts, a recessed portion is provided in the iron lid so that the iron lid is screwed to the underground iron frame or the leg portion of the bolt. Regarding the connection, the head shape of the bolt used and the outer peripheral shape used for tightening the nut (including the cap nut) are regular hexagons.

(Problems to be Solved by the Invention) The bolts and nuts as described above are not always preferable if they can be easily attached and detached. That is, there is a commercially available product that has a projection for non-return on the back side of the head of the bolt or the back side of the nut so that it cannot be removed once screwed once, but if you need to remove it, this is This is not preferable because it will damage the object to be bonded.

As mentioned above, a manhole cover for various public facilities or a bolt with a compatible shape for major facilities of companies,
Because of the nuts, they are often easily (ie, illegally) opened using compatible tools to be penetrated and junk.

Since the above-mentioned Japanese Utility Model Publication No. 50-22182 looks like a round head without a spanner engaging portion after tightening, it has a better appearance than a conventional hexagonal screw or a screw having a driver engaging groove, and further has a tack head. Even if it is suitable for a part that is difficult to remove from a place that does not look like a screw, for example, a mounting screw for a lock, it is a frustoconical shape, so it is a bag spanner when tightening or removing. A tool such as the one described above receives a pull-out force, and it is necessary to constantly apply a strong pressing force, and smooth operation cannot be performed. Especially when it is adopted for a large structure such as a manhole iron lid, the operation is difficult. It is very difficult and has the disadvantage of requiring special equipment. In addition, this manhole iron cover, etc. must be prevented from being illegally opened and penetrated due to its purpose of use, and in an emergency (by using a special tool) it must be easily and quickly opened. Therefore, there is a disadvantage that it is not suitable to use the above-described frustoconical screw.

The present invention was devised in view of such a situation as described above, and although the outer peripheral shape of the bolt head or the nut has a special shape and cannot be operated by a tool such as a general screwdriver or a spanner, An object of the present invention is to provide an iron lid mounting device for an iron frame for an iron frame such as a manhole that can be easily and freely attached and detached when using a compatible tool.

“Structure of the Invention” (Means for Solving the Problems) In order to achieve the above-mentioned object, the present inventors propose as follows.

(1) The outer peripheral shape of the nut is an elliptical outer peripheral surface that is close to a perfect circle, and the parallel side surfaces are formed on the elliptical outer peripheral surface portion. And forming a recess in the iron lid, inserting a bolt provided in the iron frame into the recess, and screwing the nut at the tip of the bolt in the recess in the iron lid. Iron lid mounting device for the frame.

(Operation) According to the present invention, the head shape of the bolt, the outer peripheral shape of the nut (the surface used for tightening in the case of a cap nut) and the inner circumference of the opening of the tool for tightening and removing the bolt and nut. The surface shape is an ellipse that is close to a perfect circle, and a commercially available box spanner, monkey spanner, yatco, spanner, etc. is used to make it a shape that does not slip even if you try to turn the bolt or nut. That is,
Since it is not a rectangular shape, even if it is not the same shape as the bolt and the nut, any corner of the inner peripheral surface of the conventional box spanner and the corner of the bolt or the like will not be engaged and rotated.
Also, since it is an ellipse, it can be rotated by a dedicated jig, and the ratio of major axis / minor axis can be appropriately selected. From the gist of the present invention, it is considerably close to a perfect circle. It is desirable that the ratio of major axis / minor axis is close to 1.0. However, if the opening and closing frequency is too high if it is too close to a perfect circle, the user may wear the outer surface of the nut or the inner surface of the tool. There is a risk that it will not be able to rotate by itself, and if the ratio of the major axis and the minor axis is extremely increased, it will be possible to rotate by sandwiching it with a monkey wrench etc. from the top, so the range of the major axis to the minor axis is 1.05 to 1.5. It is preferable.

In the case of a dedicated tool, the shape of the opening that fits the bolt and nut should be the same as the bolt and nut in terms of the ratio of major and minor diameters.
Only the size is slightly (from the length of the bolt and nut, the minor diameter 0.5 ~
There is a danger of spinning around unless it is increased. The handle has a symmetrical length in the left-right direction orthogonal to the rod-shaped body and forms a substantially T-shape, but when the bolts and nuts are very small, only one side may be used as a box spanner type. Further, in the T-shape, the central rod-shaped body may protrude slightly upward.

The nut has an outer peripheral shape that is an elliptical outer peripheral surface that is close to a perfect circle, and parallel side surfaces are formed on the elliptical outer peripheral surface. A nut having a concave portion formed on the iron lid is inserted into the concave portion of the iron lid by inserting a bolt having an iron frame in the concave portion, and the nut is screwed into the concave portion of the iron lid at the tip portion of the bolt. As described above, it is impossible to operate with a tool other than the dedicated tool that is inserted into and removed from the upper portion of the nut as described above, and it is possible to completely prevent mischief by anyone other than a specific worker who possesses the dedicated tool. Further, the tip of the bolt is a cap nut, and is effectively covered and protected by the nut having a spherical top surface, so that the attachment of water and earth and sand and the corrosion thereof can be avoided properly.

(Embodiment) FIG. 1 shows a case of a cap nut as one embodiment used in the present invention, (a) shows a plan view, and a cap nut 1 is an elliptical shape tightened by a spherical top 2 and a tool. The outer peripheral surface 3 is shown. (b) is a side view (left half) and a sectional view (right half) of the same cap nut, showing a spherical top 2, an elliptical outer peripheral surface 3, and a screw hole 4.
(c) is a bottom view, in which a screw hole 4 is formed in the center and an outer side is surrounded by an elliptical outer peripheral surface 3, but parallel side surfaces 3a and 3b are formed on both sides of the outer peripheral surface 3, and thus a nut is formed. The wall thickness of is varied depending on the radial position on the nut 1 of the elliptical outer peripheral surface 3. The major axis / minor axis in this example is 1.16.

FIG. 2 shows a special tool 5 used for attaching and detaching the cap nut 1 shown in FIG. 1, and FIG. 2 (a) is a side view (only the opening shows the right half in a sectional view). is there. An opening 7 for fitting a nut is provided at one end of the rod-shaped body 6,
A T-shaped handle 8 is formed at the other end. (b) is a bottom view of the dedicated tool 5, and shows an operation portion 9 and a handle 8 having a perfect circular outer shape having an opening 7 having an elliptical inner peripheral surface. This opening was 1.015 times larger than the outer diameter of the nut 1 for both long and short diameters.

FIG. 3 shows a sectional view of the present invention implemented as an attachment device for the iron lid 16 of a closed manhole using the cap nut 1 as described above. That is, the leg portion 13 of the bolt having the T-shaped head 12 is set on the space portion 11 formed in the iron frame 10 of the manhole, and the auxiliary fixing metal fitting 14 is further inserted and fixed, and the sealing packing 15 After putting
The iron lid 16 is covered, and a perfect circular recess 17 is formed at the end of the iron lid as shown in FIG.
The leg portion 13 of the bolt was made to appear from the hole 18 provided in the, the cap nut 1 was turned by hand, and finally it was tightened by the special tool 5 described in FIG. FIG. 4 is a plan view of the previous figure. A space 17a suitable for fitting the perfect circular operation portion 9 of the tool 5 is formed in the recess 17 around the cap nut 1.

Although the nut has been described above, the same is true in principle even if this is the head of the bolt, and the same portion as the cap nut 1 described above is formed as the enlarged head at the upper end of the bolt 13. So that it is located inside the recess 17 and the bolt 13
The male threaded portion formed at the lower end of the above may be screwed into the female threaded hole of the iron frame 10. It goes without saying that the dedicated tool to be adapted is exactly the same as that for the nut shown in FIG. Also, when the joined object can be opened from either the front side or the back side, it is of course necessary that both nuts and bolts have the same shape, and that both sides can be easily opened with a dedicated tool. Is.

"Effects of the Invention" As described in detail above, when the bolts and nuts having the shape according to the present invention are attached and detached using a dedicated tool suitable for this, the time and cost required for tightening and removing the bolts and nuts, etc. Etc. are almost the same as the conventional ones, and the nuts or bolts are sealed by applying the recesses formed in the iron lid to the attachment of the iron lid to the iron frame in public facilities or major facilities of companies. The dedicated tool acts like a key to prevent illegal intrusion and can be used safely for a long time without being misled. In addition, it is possible to effectively prevent water and earth and sand from adhering to the tip of the bolt and the resulting corrosion, and obtain sufficient durability as an outdoor facility.

[Brief description of drawings]

FIG. 1 shows the shape of the nut of the present invention. (A) is a plan view, (b) is a side view (left half) and a sectional view (right half), (c).
Is a bottom view. FIG. 2 is a nut exclusive tool of FIG. 1, (a) is a side view, (b) is a bottom view. FIG. 3 shows a cross-sectional view of a lid mounting device for a metal frame of the present invention, which is carried out for mounting a lid of a closed manhole, and FIG. 4 is a plan view of the previous figure. 1: Cap nut, 2: Spherical top part 3: Elliptical outer peripheral surface, 3a, 3b: Parallel side faces 4: Screw hole, 5: Dedicated tool 6: Rod-shaped body, 7: Opening part, 8: Handle, 9: Round shape Operation part 10: Iron frame, 11: Space part 12: T-shaped head part, 13: Leg part 14: Auxiliary fixing metal fitting, 15: Packing for sealing 16: Iron lid, 17: Recessed part 18: Provided in recessed part Hole

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Kazuo Nakagawa Inventor Kazuo Nakagawa 1 1 Minami-cho, Kawasaki-ku, Kanagawa Prefecture Sanyo Industry Co., Ltd. (72) Inventor Jun Utashiro 1-24-4 Nishigotanda, Shinagawa-ku, Tokyo Within Takigen Manufacturing Co., Ltd. (56) References JP-B-50-22182 (JP, Y2) British Patent 1188163 (GB, A)

Claims (1)

[Claims] 1. A cap nut having an outer peripheral shape of an elliptical outer peripheral surface close to a perfect circle, and parallel side surfaces formed on the elliptical outer peripheral surface portion, and one end surface of which is a spherical top portion, for a steel frame. Characterized in that a recessed portion is formed in the provided iron lid and a bolt provided with an iron frame is inserted into the recessed portion, and the nut is screwed into the tip end portion of the bolt in the recessed portion of the iron lid. Iron lid mounting device for the iron frame.