JP7511254B2 - Underground cable cover switch - Google Patents

Description

The present invention relates to an opening and closing device for an underground buried electric circuit cover panel that can safely open and close a cover panel made of, for example, concrete that is placed on the ground surface for the purpose of maintaining electric circuit equipment, etc., when promoting the elimination of utility poles by burying electric circuit equipment underground, and that is low-cost yet ensures security.

Traditionally, burying electrical wiring equipment underground not only preserves the landscape by eliminating overhead wiring and utility poles, and also makes maintenance easier, so various pole-free systems have been proposed to promote this. However, burying electrical wiring underground requires various costs, such as digging along the wiring route, burying gutter and trench structures, and installing maintenance covers on the ground surface. In particular, while covers installed on the ground surface can be easily opened and closed for maintenance, if they can be easily opened and closed by tampering or other means, the safety of the wiring route cannot be ensured.

In light of this, a conventional locking device for electric cable common trench lids is provided with a rotating locking piece that detachably engages with a receiving frame between the opening wall of a buried box where the openable lid is placed and locked, and the rotating locking piece of this locking device is locked or unlocked by, for example, locking or unlocking with a cylinder lock. In addition, there is a manhole lid in Patent Document 2 in which a groove and a protruding part are formed in a recessed fitting part formed in the lid, and a T-shaped hook is inserted into the groove of the recessed fitting part and rotated to engage with the protruding part, lifting and opening the lid.

JP 2012-162881 A Japanese Utility Model Application Publication No. 6-87439

However, in such conventional locking devices, the cover plate locking device shown in Patent Document 1, which is equipped with a cylinder lock, requires not only a protective plate to protect the cylinder lock, but also a screw-fastening structure to prevent the protective plate from being easily opened. This increases installation costs because the cylinder lock itself is expensive, and can lead to accidents due to forgetting to lock the cylinder lock. In addition, the manhole cover shown in Patent Document 2, which uses a T-shaped hook engagement, can be easily opened if a member with a similar shape to this T-shaped hook is used, and it is not possible to prevent damage to the wiring members stored inside due to tampering. Or, even if a lock driver that corresponds to a specially shaped keyhole is used, the same situation will occur if a driver that matches the special shape is used.

The present invention was created in consideration of the various problems that existed in the past as described above, and aims to provide an opening and closing device for a cover panel for underground buried electrical circuits that not only allows the cover panel to be opened and closed safely, but also allows it to be constructed at low cost and ensures security when opening and closing a cover panel, for example made of concrete, that is installed on the ground surface in an underground electrical circuit constructed by burying a trench structure to store wiring.

In order to solve the above-mentioned problems, the present invention comprises an engagement body 1 that is embedded in the cover plate F of a buried electrical circuit and has a magnetically attachable hook rod 11 inserted therein that slides up and down, and a hook body 20 that magnetically attaches and lifts the hook rod 11 of the engagement body 1 to lift the cover plate F. The engagement body 1 comprises an engagement main body 2 that is embedded in the cover plate F, and the hook rod 11 that is inserted into the engagement main body 2 and that, after the pull-out head 12 formed at the upper end is magnetically engaged by the hook body 20 and pulled out, engages the engagement protrusion 13 provided at the lower part with the engagement body 1 to lift the cover plate F. The hook body 20 is characterized in that it comprises a hook housing 21 with an open side, a connecting part 22 that connects to a hoisting machine C, a magnet body 23 that is supported so as to be able to swing freely on the hook housing 21 and magnetically attaches and pulls out the pull-out head 12 of the hook rod 11, and a support part 28 that engages and supports the pulled-out pull-out head 12.
The engagement body 2 of the engagement body 1 can be configured to have a head storage chamber 4 at the upper part, in which the pull-out head 12 is stored and exposed on the surface of the cover plate F, and an engagement chamber 6 at the lower part, which has an engagement upper wall 7 that engages with the engagement protrusion 13 of the hook rod 11 that has been pulled out and moved upward.
The drawer head 12 can be stored inside the head storage chamber 4 and can be configured to have a height that is not greater than the interior height of the head storage chamber 4.
The outer peripheral surface of the engaging body 2 has a larger diameter at the bottom compared to the top, thereby forming a suspended step portion 3 at approximately the center of the height of the engaging body 2, and the lower portion can be configured as a tapered surface that gradually becomes smaller in diameter as it approaches the bottom.
The hook housing 21 of the hook body 20 is formed so as to have an approximately H-shape when viewed from above by connecting the opposing left and right side walls with a central wall, and the connecting portion 22 to which the hook member of a specified hoisting machine C is hooked can be configured as a hole portion opened in the central wall.
The magnetic body 23 of the hook body 20 can be constructed by fitting a tubular oscillating pipe 25 so as to be able to oscillate freely onto a support shaft 24 which is supported and connected between the left and right side walls of the hook housing 21, and by connecting an extraction rod 26 having a magnet 27 connected to its tip to this oscillating pipe 25.

In the opening and closing device for a cover panel for an underground buried electric circuit according to the present invention configured as described above, the hook rod 11 of the engagement body 1 embedded in the cover panel F that closes the opening of the buried electric circuit is magnetically attracted and pulled up by the hook body 20 connected to the hoisting machine C, and the support part 28 of the hook body 20 engages with the hook rod 11 and lifts it up. Then, the engagement protrusion 13 of the hook rod 11 also engages with the engagement body 1, and the lifting action of the hoisting machine C lifts the cover panel F and opens the buried electric circuit.
The hook rod 11 inserted in the engaging body 1 has its upper end pull-out head 12 stored in the head storage chamber 4 in the engaging body 1 and exposed on the upper surface of the cover plate F, but the stored state is not noticeable in the head storage chamber 4 and is only operated by the pull-out action due to the magnetic attraction of the magnetic body 23, making it difficult to pull out by tampering or other means.
The hook body 20 is suspended by engaging the support portion 28 with the pull-out head 12 of the hook rod 11 which is magnetically pulled out by the magnetic body 23, so that the engaging protrusion 13 of the hook rod 11 which slides upward engages with the engaging body 1, and the cover plate F itself is lifted through this engaging body 1, thereby opening the buried electrical circuit.
The hook body 20 has the magnet body 23 connected to the swinging pipe 25 fitted to the support shaft 24 so that it can swing freely, so that when the hook body 20 itself is in an inclined state, it always protrudes vertically from the open side of the hook housing 21. When opening the cover plate F, the hook body 20 in an inclined position is simply brought to the position of the engaging body 1, and the magnet body 23 magnetically attracts the drawer head 12, and by lifting it upward, the hook body 20 itself swings, and after the swinging, it assumes an upright position, engaging the support part 28 with the drawer head 12.

As the present invention is configured as described above, it is composed of an engagement body 1 equipped with a magnetically attachable hook rod 11 that is embedded in the cover plate F, and a hook body 20 that lifts the engagement body 1 itself that is engaged by the hook rod 11. Unlike the conventional method, the cover plate F can be opened and closed safely without the need for a special cylinder lock or a specially shaped release tool, and security can be ensured while being low cost.

That is, in the present invention, the engaging body 1 and the hook body 20 are provided, the engaging body 1 is inserted into the engaging main body 2 embedded in the cover plate F, and is provided with a hook rod 11 which engages with the engaging protrusion 13 provided at the bottom and lifts the cover plate F after the pull-out head 12 is magnetically attracted and pulled out by the hook body 20, and the hook body 20 is provided with a hook housing 21 with an open side, a connecting part 22 which connects to the hoisting machine C, a magnet body 23 which is supported so as to be swingable on the hook housing 21 and magnetically attracts and pulls out the pull-out head 12, and a support part 28 which engages and supports the pulled-out pull-out head 12. As a result, the engaging body 1 is embedded and arranged in the cover plate F, and the cover plate F can be opened and closed by the hoisting machine C through a smooth series of operations of magnetic attraction and pulling out by the hook body 20 and engagement.

Moreover, the pull-out head 12 of the hook rod 11 has a spherical top, an outer diameter that is almost the same as the inner diameter of the head storage chamber 4, and a height that is not large compared to the interior height of the head storage chamber 4. This eliminates the need to employ a special locking structure such as an expensive cylinder lock, as in the past, and makes it possible to protect the opening and closing device from tampering and other factors without the need for a locking structure.

The tapered surface at the bottom of the engagement body 1 allows it to be integrated with the lid plate F when embedded, and the lifting section 3 ensures its integration with the lid plate F when lifting with the lifting machine C, so the engagement body 1 will not separate or dismantle when lifting the lid plate F, allowing the work to be carried out safely.

The hook body 20 can be easily connected to the lifting machine C by having a hole-shaped connecting portion 22 in the hook housing 21, and the support portion 28 can be easily engaged with the underside of the pulled-out head portion 12 by simply standing the hook body 20 upright.

The reference numerals in the Means for Solving the Problems and Effects of the Invention sections are used to facilitate reference to the components shown in the drawings. The present invention is not limited to the structure, shape, etc. shown by these descriptions and the reference numerals in the drawings.

1 is a schematic perspective view, partly cut away, showing one embodiment of the present invention; FIG. 11 is a cross-sectional view of the cover plate when it is lifted and opened. FIG. 4 is a cross-sectional view taken along the arrow in FIG. 3. FIG. FIG. 11 is a cross-sectional view of the hook body when the magnet is magnetically attached to the hook rod of the engagement body. FIG. 11 is a cross-sectional view showing the hook rod being pulled out and the hook body engaging with the hook rod. FIG. 11 is a cross-sectional view of the hook rod when the hook body is engaged with the hook rod. FIG. 11 is a cross-sectional view showing the state when the hoisting operation is started by engaging the hoisting hook with the hook body. FIG. 13 is a cross-sectional view of the same during the opening operation in which the cover plate is lifted.

One embodiment of the present invention will be described below with reference to the drawings. The reference number 1 in the drawings is an engagement body that is embedded integrally with a cover plate F made of, for example, concrete, steel, or cast iron, which is used to cover the opening of a buried electrical circuit (not shown). The cover plate F can be removed from the buried electrical circuit by hoisting it up with a specified lifting machine via a hook body 20 that engages with the engagement body 1. The cover plate F closes the opening of the buried electrical circuit by performing the same procedure in reverse as when removing it.

When the engaging body 1 is placed on the cover plate F, it is embedded integrally in the cover plate F with the opening of the head storage chamber 4, which is partitioned and formed in the upper part (described later), exposed and open at least at the surface position of the cover plate F.

The engagement body 1 itself comprises an engagement body 2 and a hook rod 11 which are embedded in the cover plate F. The hook rod 11 is inserted into the engagement body 2, and after the pull-out head 12 formed at the upper end is magnetically attached by the hook body 20 and pulled out, the engagement protrusion 13 provided at the bottom engages with the engagement body 2 to lift the cover plate F.

The engagement body 2 is embedded in the lid plate F and is integrated with the lid plate F so that when it is lifted by the lifting machine C, it is lifted together with the lid plate F. For this reason, the outer periphery of the engagement body 2 has a larger diameter at the bottom compared to the top, forming a lifting step 3 at approximately the center of the height of the engagement body 2, and the bottom has a tapered surface that gradually becomes smaller in diameter as it approaches the lower opening. In this way, the engagement body 2 is integrated with the lid plate F so that it will not fall off or become detached from the lid plate F upwards or downwards.

As described above, a hook rod 11 which slides along the vertical direction of the engagement body 2 itself is inserted into the engagement body 2, and this hook rod 11 has a magnetically attachable umbrella-shaped pull-out head 12 at its upper end, and a flange-shaped engagement protrusion 13 at its lower end which directly engages with the engagement body 2 within the lower part of the engagement body 2.

As shown in the figure, the retraction head 12 has a spherical or disc-shaped top, for example, and is made of a magnetically attachable material. The engagement protrusion 13 is made of a washer material that is nutted onto the male thread formed at the lower end of the hook rod 11, but is not limited to this. When the hook rod 11 is retracted by the retraction head 12, the distance between the bottom surface of the retraction head 12 and the open end of the head storage chamber 4 is set to a height sufficient to allow the support portion 28 of the hook body 20, which will be described later, to slide in.

The retractable head 12 need not necessarily have a spherical or disc-shaped top or a circular shape, as long as it is stored neatly inside the head storage chamber 4 (described later) in the engagement body 2 and is not noticeable on the road surface. For example, the outer shape of the retractable head 12 may be a shape that roughly matches the inner shape of the head storage chamber 4, such as a polygonal shape, and the point is that the retractable head 12 stored in the head storage chamber 4 cannot be pulled out by tampering using a member or equipment that can be inserted into a gap that may occur between the head storage chamber 4 and the retractable head 12.

The engagement body 2 has a head storage chamber 4 at its upper part, which stores the pull-out head 12 while exposing it on the surface of the cover plate F, and an engagement chamber 6 at its lower part, which has an engagement upper wall 7 with which the engagement protrusion 13 of the hook rod 11, which is pulled out and moved upward, engages. As shown in the figure, the head storage chamber 4 and the engagement chamber 6 are partitioned by a partition wall 5, and the hook rod 11 is inserted through an insertion hole drilled in the partition wall 5, so that the pull-out head 12 before being pulled out remains on the partition wall 5 and does not protrude above the opening of the head storage chamber 4.

The upper engagement wall 7 in the engagement chamber 6 is inverted and stepped, and its inner diameter is not larger than the outer diameter of the engagement protrusion 13, so that it reliably engages with the engagement protrusion 13 when the hook rod 11 slides upward. The reference numeral 14 in the figure denotes a reinforcing protrusion formed on the upper inner surface of the engagement chamber 6, which prevents the side wall of the engagement chamber 6 from becoming distorted.

In addition, although the engagement chamber 6 in the engagement body 2 in the illustrated example has an open structure on the underside of the cover plate F, it does not have to be open and may be closed if necessary.

The hook body 20, which lifts the cover plate F via the engagement body 1, is made up of a hook housing 21 with an open side, a linking part 22 that links to the lifting machine C, a magnetic body 23 that is supported so as to be able to swing freely on the hook housing 21 and magnetically attracts and draws out the pull-out head 12 of the hook rod 11, and a support part 28 that engages and supports the pulled-out pull-out head 12.

As shown in the figure, the hook housing 21 is formed so as to have an approximately H-shape when viewed from above by connecting the opposing left and right side walls with a central wall, and an opening formed in the central wall serves as a connecting part 22 to which a hook member such as a hook ring of a specified lifting machine C can be hooked.

The magnetic body 23 is formed by connecting a pull-out rod 26, which has a magnet 27 connected to its tip, to a tubular swinging pipe 25 that is fitted so as to be able to swing freely on a support shaft 24 that is supported and connected between the left and right side walls. In this way, the pull-out rod 26 swings freely within the hook housing 21, and, together with the weight of the magnet 27, is always suspended vertically from the hook housing 21. In other words, when the hook body 20 itself is tilted, the pull-out rod 26 protrudes from the open side, and when the hook body 20 itself is swung to change to an upright position, the pull-out rod 26 is stored within the hook body 20, and the lower support part 28 moves toward the position of the magnet 27 before the change.

The support portion 28 is bifurcated with an opening on the open side of the hook housing 21, and is integrally connected between the lower edges of the left and right side walls of the hook housing 21. In the illustrated example, curved guide pieces 29 are formed at the ends of both sides of the opening of the support portion 28, and the hook body 20 is set at an inclination in a state in which the magnet body 23 is protruding from the hook housing 21 on the cover plate F. When the magnet body 23 magnetically attracts the retractable head 12 of the hook rod 11 and retracts it, the hook housing 21 changes to an upright position so as to be lifted, and the support portion 28 slides into the underside of the retractable head 12, allowing the support portion 28 to smoothly engage with the retractable head 12.

Next, an example of usage will be described. As shown in the figure, the upper opening of the head storage chamber 4 is exposed on the top surface of the cover plate F, and the engaging body 1 is embedded and fixed integrally to the cover plate F. If necessary, the opening of the head storage chamber 4 can be closed with a suitable cover material.

When lifting and opening the cover plate F, first, as shown in FIG. 6, the pull-out rod 26 is set in an inclined position on the open side of the hook body 20 with the worker's own fingers, and the magnet 27 at the front end is positioned in the head storage chamber 4 of the engagement body 1 and magnetically attached. After magnetic attachment, as shown in FIG. 7, the hook body 20 is lifted upward and the connecting part 22 of the hook rod 11 is pulled out. Then, by changing the hook body 20, which was in an inclined position until then, to an upright position, the support part 28 is engaged with the underside of the pull-out head 12 by the guide piece 29. After the support part 28 engages with the underside of the pull-out head 12, the engagement body 1 may slide slightly downward as shown in FIG. 8. Next, as shown in FIG. 9, the hook member of the lifting machine C is connected to the connecting part 22 of the hook body 20, and the cover plate F can be lifted by lifting it as shown in FIG. 10. In this way, the cover plate F is removed and the buried electric circuit is opened.

For example, when closing a buried electrical circuit after maintenance work, the procedure for lifting and opening the circuit can be reversed.

C...Lifting machine F...Cover plate 1...Engagement body 2...Engagement main body 3...Lifting stage 4...Head storage chamber 5...Bulkhead 6...Engagement chamber 7...Engagement upper wall 11...Hook rod 12...Pull-out head 13...Engagement protrusion 14...Reinforcing protrusion 20...Hook body 21...Hook housing 22...Connecting portion 23...Magnetic body 24...Support shaft 25...Oscillating pipe 26...Pull-out rod 27...Magnet 28...Support portion 29...Guide piece

Claims (6)

a hook rod that is inserted into the cover panel of the buried electrical circuit and that slides vertically and has a magnetically attachable hook rod inserted therein; and a hook body that lifts the cover panel by magnetically attaching and lifting the hook rod of the engagement body, wherein the engagement body comprises an engagement main body that is embedded in the cover panel, and the hook rod that is inserted into the engagement main body and that, after a pull-out head formed on the upper end is magnetically engaged by the hook body and pulled out, engages an engagement protrusion provided on the lower part with the engagement body to lift the cover panel, and the hook body comprises a hook housing with an open side, a connecting part that connects to a lifting machine, a magnet body that is supported in a swingable manner on the hook housing and that magnetically attaches and pulls out the pull-out head of the hook rod, and a support part that engages and supports the pulled-out head. The opening and closing device for a cover panel for an underground buried electrical circuit according to claim 1, wherein the engaging body of the engaging member has a head storage chamber at the top for storing the pull-out head exposed on the surface of the cover panel, and an engaging chamber at the bottom having an engaging upper wall for engaging the engaging protrusion of the hook rod that has been pulled out and moved upward. The opening and closing device for a cover panel for an underground buried electrical circuit according to claim 1 or 2, wherein the pull-out head is capable of being stored inside the head storage chamber and has a height that is not greater than the interior height of the head storage chamber. The opening and closing device for a cover panel for an underground electric circuit according to any one of claims 1 to 3, wherein the outer peripheral surface of the engaging body has a larger diameter at the bottom than at the top, forming a suspended step at approximately the center of the height of the engaging body, and the lower part has a tapered surface that gradually becomes smaller in diameter as it approaches the bottom. The hook housing of the hook body is formed so as to have an approximately H-shape when viewed from above by connecting the opposing left and right side walls with a central wall, and the connecting portion to which the hook member of a specified hoisting machine is hooked is a hole portion formed in the central wall, as described in any one of claims 1 to 4. The magnetic body of the hook body is formed by fitting a tubular oscillating pipe to a support shaft that is connected between the left and right side walls of the hook housing so that the oscillating pipe can freely oscillate, and connecting a pull-out rod with a magnet connected to its tip to the oscillating pipe. The opening and closing device for a cover panel for an underground buried electrical circuit according to any one of claims 1 to 5.

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