JP2005054421A - Cover device for operation tool hole of manhole cover - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cover device for an operation tool hole of a manhole cover, which is structurally simplified to the utmost, which can be manufactured and worked at a low cost, and which enables an operation for attachment/detachment of a cover plate to be lightly performed by a screw motion. <P>SOLUTION: A stopper plate 4 is supported on an undersurface of the cover plate 3 for covering the operation tool hole 2 of the manhole cover 1 from a top surface side, in such a manner as to be vertically turnable on a pivot 5; a driving bolt 7 is screwed into a screw hole 6 which vertically passes through the cover plate 3; a tip part 8 of the driving bolt 7 butts against a top surface of a base-end-side part 9 of the stopper plate 4; the amount of the screwing of the driving bolt 7 into the screw hole 6 is increased/decreased so that the stopper plate 4 can be turned in the hole 2; and a tip-side part 10 of the stopper plate 4 is engaged with/disengaged from a retaining part 11 on the side of the manhole cover 1, from an undersurface side, so that the cover plate 3 can be detachably fastened and fixed to the manhole cover 1. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a cover device that closes a tool hole into which an operation tool such as a bar is inserted when a manhole cover is opened or closed.

  The conventional cover device has a long dimension and a short dimension corresponding to the operation tool hole of the manhole cover, and is provided with a locking hole at the center portion where the neck portion of the operation screw is supported so as to be freely rotatable. A cover plate that is joined to the lower surface side of the cover plate, and has a U-shaped support frame plate that is provided on the bottom plate portion so as to support the lower end of the operating screw so as to be freely rotatable; The sandwiching plate is disposed in the short direction, screwed into the operation screw at the center screw hole, and moved vertically along the support frame plate by forward and reverse rotation of the operation screw. The longitudinal dimension is set to be longer than the short dimension of the operation tool hole and shorter than the longitudinal dimension of the operation tool hole, and the edge of the operation tool hole is set between both ends of the sandwiching plate and the side edge of the cover plate. (See Patent Document 1).

  In order to remove this cover device from the upper surface of the operation tool hole, the operation screw is turned in a specific direction from the upper surface side of the cover plate, and the clamping plate is moved downward as it is guided and regulated by the support frame plate. The clamping of the edge of the operation tool hole by the both ends of the plate and the side edge of the cover plate is released. Next, the cover plate is rotated by 90 degrees along the upper surface of the manhole cover so that the longitudinal direction of the sandwiching plate matches the longitudinal direction of the operation tool hole. Since the longitudinal dimension of the sandwiching plate is set to be shorter than the longitudinal dimension of the operation tool hole as described above when arranged in this way, the sandwiching plate and the support frame plate are extracted from the operation tool hole, and the cover device The whole can be removed from the operation tool hole.

  However, in this conventional device, since the entire cover device must be rotated 90 degrees after the operating screw is turned in the loosening direction, the detaching operation becomes two-step and the workability is not good. In addition, when the cover plate is attached to the manhole cover due to rusting or clogging with dust due to long-term use, there is a problem that the cover plate cannot be rotated 90 degrees easily.

  The cover device proposed as an improvement measure for these problems has a longitudinal dimension and a short dimension corresponding to the operation tool hole of the manhole cover, and has a through-hole in which the neck of the operation screw is loosely fitted. A cover plate that covers the operation tool hole from the upper surface; and a screw hole that is joined to the lower surface side of the cover plate by two guide leg plates at a distance from each other and into which the screw shaft portion of the operation screw is screwed. The support bottom plate; the longitudinal dimension is longer than the short dimension of the operation tool hole and shorter than the longitudinal dimension of the operation tool hole, and is screwed into the screw shaft portion of the operation screw at the central screw hole, An operation screw with a margin space between the clamping plate that moves up and down in contact with one side edge of the guide leg plate by reverse rotation and the support bottom plate so that the upper part of the operation screw rises from the upper surface of the cover plate And a retaining nut provided at the lower end of the.

  In this cover device, after the operating tool hole is closed from the upper surface side by the cover plate, when the operating screw is turned in a specific direction by an appropriate rotating tool, the clamping plate follows the operating screw and integrally rotates. When the sandwich plate rotates 90 degrees with respect to the cover plate and contacts one side edge of the guide leg plate, the longitudinal direction of the sandwich plate is aligned with the short direction of the operation tool hole. Both end portions in the longitudinal direction are on the lower surface side of the edge portion of the operation tool hole. If the rotation of the operation screw in a specific direction is continued, the sandwiching plate is translated upward along the guide leg plate while being further prevented from rotating by the guide leg plate. Sandwiches the edge of the operation tool hole between both ends of the sandwiching plate in the longitudinal direction and the side edge of the cover plate.

  When the operation screw is turned in the direction opposite to the specific direction in order to remove the cover device, the clamping plate rotates integrally with the operation screw and rotates 90 degrees with respect to the cover plate. Will collide with the side edges. At this stage, the sandwiching plate is disposed so that the longitudinal direction thereof is aligned with the longitudinal direction of the operation tool hole, and has come to a position separated from the edge of the operation tool hole. If the reverse rotation of the operation screw is continued here, the sandwiching plate will be translated downward along the guide leg plate while being prevented from further rotation by the guide leg plate. Only the upper part of the operation screw is lifted from the upper surface of the cover plate. Thus, the cover device is removed from the operation tool hole by pulling the upper portion of the operation screw upward.

  This cover device is improved over the conventional cover device in that it is no longer necessary to rotate the cover plate 90 degrees along the upper surface of the manhole cover. The cost is bulky, and the screw motion of the operation screw is converted into the parallel linear motion of the sandwiching plate through the interposition of the side edges of the guide leg plate, so that the frictional resistance during operation is large.

Utility Model Registration No. 2531581 Japanese Patent No. 3148720

  The problems to be solved are that the structure is simplified to the limit and the manufacturing process is performed at a low cost, and that the cover plate can be attached and detached by screw movement with less frictional resistance and lightly.

  A stopper plate 4 is rotatably supported by a pivot 5 on the lower surface side of a cover plate 3 that covers the operation tool hole 2 of the manhole cover 1 from the upper surface side, and a drive bolt 7 is screwed into a screw hole 6 that penetrates the cover plate 3. The front end 8 of the drive bolt 7 is abutted against the proximal end portion 9 of the stopper plate 4, and the amount of screwing of the drive bolt 7 into the screw hole 6 is increased or decreased to rotate the stopper plate 4 within the operation tool hole 2. The most important feature is that the cover plate 3 is detachably fastened and fixed to the manhole cover 1 by engaging / disengaging the front end portion 10 of the stopper plate 4 with the receiving portion 11 on the manhole cover 1 side.

  In the cover device of the present invention, the stopper plate 4 is directly moved around the pivot shaft 5 by turning the drive bolt 7 with the distal end portion 8 of the drive bolt 7 abutted against the proximal end portion 9 of the stopper plate 4. Since it is rotationally driven, there is an advantage that the frictional resistance is very small during this operation, and the cover plate 3 can be smoothly fixed and released smoothly with a small force.

Further, it is sufficient to loosen the drive bolt 7 to release the tightening and fixing, and then lift the cover plate 3 as it is, and it is necessary to rotate the cover plate 3 with respect to the operation tool hole 2 by 90 degrees. Since there is no operation procedure is simplified.
Since it is constituted by very few parts such as the cover plate 3, the stopper plate 4, the pivot shaft 5 and the drive bolt 7, and the structure is simplified to the limit, there is an advantage that the cost of the manufacturing process is low.

The cover plate 3 is formed of a rust-proof metal plate, and the metal drive bolt 7 and the stopper plate 4 are also rust-proofed. The stopper plate 4 is bent in a U shape near the center so as to hold the pivot shaft 5. The receiving portion 11 on the metal manhole cover 1 side is formed in a substantially semicircular shape at the edge side portion of the operation tool hole 2. The distal end side portion 10 of the stopper plate 4 is curved so as to wrap the receiving portion 11 from the lower surface side. The base end side portion 9 of the stopper plate is bent so as to contact the lower end surface of the drive bolt 7 when the drive bolt 7 is loosened to the maximum.
By doing so, the pushing force due to screwing of the drive bolt 7 is transmitted to the stopper plate 4 without loss, and the tip end portion 10 holds the receiving portion 11 at the end of rotation of the stopper plate 4. Thus, the cover plate 3 does not skid along the upper surface of the manhole cover 1.

FIG. 1 is a plan view of a working state of an embodiment of the device of the present invention, in which an operation tool hole 2 of a manhole cover 1 is formed in a submerged tunnel shape that is curved in the vertical direction with a receiving part 11 in between. The two entrance / exit portions 2a and 2b are opened upward.
The screw hole 6 is vertically arranged at a position shifted to one side of the cover plate 3, and is tapped into a circular thick portion 12 protruding toward the lower surface. An enlarged hole 14 for accommodating the head 13 of the drive bolt 7 is formed in the upper part of the screw hole 6. A pair of bearing plate portions 15 and 16 project from the lower surface of the cover plate 3. The pin-shaped pivot 5 is arranged in parallel with the upper surface of the cover plate 3, and is fixed to the bearing plate portions 15, 16 with both ends being prevented from coming off. On the opposite side of the lower surface of the cover plate 3, a positioning projection 17 is projected.
A delta-shaped drive recess 19 is formed at the tip of the operation handle 18, and a delta-shaped passive protrusion 20 is formed at the head 13 of the drive bolt 7.

As shown in FIG. 8, with the drive bolt 7 sufficiently relaxed, the positioning projection 17 is inserted into one of the entrance / exit portions 2b of the operation tool hole 2, and the bearing plate portions 15 and 16 are inserted into the other of the operation tool holes 2. The cover plate 3 is placed on the upper surface of the manhole cover 1 and the entire operation tool hole 2 is closed with the cover plate 3.
In this initial state, the distal end side portion 10 of the stopper plate 4 hangs down into the entrance / exit portion 2 a, and the upper surface of the proximal end portion 9 of the stopper plate 4 is in contact with the lower surface of the distal end portion 8 of the drive bolt 7.
The pivot 5 can be formed integrally with the stopper plate 4.

  When the operation handle 18 is turned in a specific direction after the drive recess 19 of the operation handle 18 is fitted to the passive protrusion 20 of the drive bolt 7, the drive bolt 7 moves downward along the screw hole 6. The stopper plate 4 is rotated around the pivot 5 by being pushed against the upper surface of the base end portion 9 by the distal end portion 8 of the drive bolt 7. At the final stage where the head 13 of the drive bolt 7 is accommodated in the enlarged hole 14 of the cover plate 3, as shown in FIG. 2, the tip side portion 10 of the stopper plate 4 is not attached to the receiving portion 11 on the manhole cover 1 side. Engage to hold from the bottom side.

  In this final stage, as shown in FIG. 2, the base end side portion 9 of the stopper plate 4 is disposed vertically and is in contact with the side surface of the tip end portion 8 of the drive bolt 7. Thus, the cover plate 3 is firmly fastened and fixed to the manhole cover 1. Side cover prevention of the cover plate 3 is also performed by the positioning protrusion 17 engaging the side surface of the receiving portion 11. After confirming that the cover plate 3 is tightened and fixed, the operation handle 18 is pulled out from the drive bolt 7.

  When the manhole cover 1 is opened for wiring work or the like in the common groove, the operation handle 18 is turned in the direction opposite to the specific direction. By this rotation operation, the drive bolt 7 is lifted from the cover plate 3 along the screw hole 6. In the process of the upward movement of the drive bolt 7, the contact point between the base end side portion 9 of the stopper plate 4 and the drive bolt 7 changes from the side surface of the distal end portion 8 to the lower end surface, and is in the state shown in FIG. To reach.

  Here, the operation handle 18 is removed, and the operator grips the head 13 of the drive bolt 7, whereby the cover plate 3 is removed from the operation tool hole 2. Thereafter, a bar-shaped operation tool (not shown) having a curved tip is inserted from the entrance / exit part 2b of the operation tool hole 2 into the entrance / exit part 2a, so that the manhole cover 1 is removed from the fixed cylinder 21 of the manhole. Removed.

It is a principal part top view of the manhole cover which attached the cover apparatus which concerns on one Example of this invention. It is a principal part longitudinal cross-sectional view of this manhole cover. It is a top view of this cover apparatus. It is a bottom view of the cover device. It is a right view of this cover apparatus. It is a front view of the rotation operation handle used for this cover device. It is a top view of the operation handle. It is a longitudinal cross-sectional view of the cover apparatus in the state which loosened the drive bolt. It is a principal part top view of the manhole cover in the state which removed this cover apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manhole cover 2 Operation tool hole 3 Cover plate 4 Stopper plate 5 Pivot 6 Screw hole 7 Drive bolt 8 Drive bolt distal end 9 Stopper plate proximal end portion 10 Stopper plate distal end portion 11 Manhole cover side receiving portion 18 Operation handle

Claims (1)

  A stopper plate 4 is rotatably supported by a pivot 5 on the lower surface side of a cover plate 3 that covers the operation tool hole 2 of the manhole cover 1 from the upper surface side, and a drive bolt 7 is screwed into a screw hole 6 that penetrates the cover plate 3. The front end 8 of the drive bolt 7 is abutted against the proximal end portion 9 of the stopper plate 4, and the amount of screwing of the drive bolt 7 into the screw hole 6 is increased or decreased to rotate the stopper plate 4 within the operation tool hole 2. For the operation tool hole of the manhole cover in which the cover plate 3 is detachably fastened and fixed to the manhole cover 1 by engaging / disengaging the front end portion 10 of the stopper plate 4 with the receiving portion 11 on the manhole cover 1 side. Cover device.

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