JPH0118683Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention relates to a locking device for a cover for an underground structure such as a manhole.

[Prior art and its problems]

BACKGROUND ART Various types of underground structure covers have been proposed with locking devices for the purpose of preventing illegal dumping, trespassing, and preventing the cover from being blown off by fluid pumping from underground. However, the structure to ensure the locking state is complicated,
This complicates the unlocking operation, and there is also the problem that locks with a simple structure can be easily unlocked and do not function as a lock.

[Problem that the invention attempts to solve]

The purpose of the present invention is to eliminate the shortcomings of these conventional locking devices, and to provide a locking device for underground structure lids that has a simple structure and is capable of reliably locking and unlocking operations. It's about doing.

[Means for solving problems]

The structure and operation of the present invention will be explained below based on drawings showing embodiments.

In Fig. 1, numeral 1 indicates a lid that is placed in contact with the steeply sloped receiving surface of the frame 2, and 2' is a locking protrusion for locking a lock provided inside the frame 2. They may be provided as many as necessary to lock the lid, for example, at two positions on both ends of the diameter of the inner circumference of the circular receiving frame. Reference numeral 3 indicates a lock rotatably supported by a pivot shaft 4 on the lower side of the lid 1 in correspondence with the locking projection 2'. The lock 3 has a locking portion 3a that locks with the lower side of the locking protrusion 2' in the locked state, and a locking groove portion 3b on the opposite side for rotating the lock 3. An end portion of a disk-shaped actuating member 5 for rotating the lock 3 is inserted into the engaging groove portion 3b. The disk-shaped operating member 5 is attached to a threaded bolt 6. The threaded bolt 6 passes through the lid 1 and is rotatably supported via a fixing nut 7 that locks its rotation, and its head 6' is inserted into a recess formed on the upper side of the lid 1. It is structured so that it can be accommodated in . The fixing nut 7 has a polygonal shape or a shape having a similar function, and is accommodated in a nut storage chamber 7a provided on the back surface of the lid 1 and having an internal shape similar to the fixing nut 7. A nut 7 is placed so that it does not rotate or move up and down as the threaded bolt 6 rotates and moves up and down, and the threaded bolt 6 is screwed into the nut 7. Further, the disk-shaped actuating member 5 can be attached and fixed to the bolt 6 by any means, but as shown in the figure, a nut 8 is screwed into the lower part of the bolt 6, and a nut 8 is screwed into the cotter pin hole 6''. It is also possible to fix it by fixing it with a split pin.

Next, the opening/closing operation of an underground structure cover having such a locking device will be explained.

FIG. 1 shows a state in which the lid 1 is closed and locked. When opening the lid 1 from this state, the head 6' of the bolt 6 is rotated. At this time, Natsuto 7
Since the bolt 6 is provided without rotating or moving up and down within the nut housing chamber 7a, rotation of the head 6' causes the bolt 6 and the actuating member 5 fixed thereto to rise. Then, the upper surface of the actuating member 5 pushes up the upper surface of the engagement groove 3b to rotate the lock 3 counterclockwise. When the lock 3 is rotated to the position shown in FIG. 2, the engagement portion 3a of the lock 3 is disengaged from the engagement projection 2' of the frame 2. When the lid 1 is provided with two locks 3, the lid 1 can be opened by rotating both locks 3 in this manner.

Next, when closing the lid, pull up the bolt 6 and retract the lock 3 as shown in Figure 2, and then move the lid 1 to the frame 2.
By fitting and mounting the bolt on a steeply sloped surface, and then rotating the head 6' of the bolt in the opposite direction, the operating member 5 is locked in the engagement groove 3b of the lock 3. It is possible to reliably return to the locked state shown in Figure 1.

[Effect of idea]

Although the locking device of the present invention has a simple structure, it can lock and unlock reliably.Furthermore, even if pressure is applied to lift the lid due to fluid turbulence, the lid does not swing. This has the effect of being able to maintain a secure locked state.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the invention. 1... Lid, 2... Frame, 2'... Locking protrusion, 3...
...lock, 3a...engaging portion, 3b...engaging groove, 4...
...Pivot shaft, 5... Operating member, 6... Bolt, 7...
...Natsuto.

Claims (1)

[Claims for Utility Model Registration] A locking projection 2' protruding from the inner circumferential wall of the frame 2, and a locking portion rotatably supported on the lower surface of the lid 1 and locking to the locking projection 2'. A lock 3 having a lock 3a and an engagement groove 3b on the opposite side thereof, a disc-shaped actuating member 5 inserted into and engaged with the engagement groove 3b of the lock 3, and a screw fixing the disc-shaped actuating member 5. Attached bolt 6
The threaded bolt 6 passes through the lid 1 and is rotatable by a fixing nut 7 housed in a nut storage chamber 7a provided on the underside of the lid 1 with vertical movement and rotation restricted. A locking device for a lid for an underground structure, characterized in that the operating head 6' of the threaded bolt 6 is housed in a recess 1' provided on the upper surface of the lid 1.