JPH0452282Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Technical Field) The present invention relates to a manhole cover device, and particularly relates to an improvement of a manhole cover device with a locking mechanism.

(Prior Art) A type of manhole cover device that opens and closes the opening of a manhole includes a receiving frame that is installed in a fixed position at the opening of the manhole, and a lid that opens and closes the opening of the receiving frame with a predetermined hinge. There is a type that is attached via a mechanism, and the opening of the receiving frame is opened and closed by rotating the lid around the hinge mechanism. For example, those disclosed in JP-A-60-195341 and JP-A-61-89053 are examples.

By the way, in such a manhole cover device,
In the past, the lids could be opened and closed easily by anyone, but in recent years, there has been a need to prevent unauthorized persons from opening and closing the lids, especially for those used in gas manholes, etc. began to be loudly shouted. Therefore, in such a manhole cover device, a predetermined locking metal fitting is provided at a suitable position on the periphery of the cover body so as to be rotatable around one axis substantially perpendicular to the plate surface of the cover body, and furthermore, the locking metal fitting is attached to the receiving frame. By forming an engaging protrusion that can be engaged with the inner circumferential portion of the receiving frame and engaging the engaging protrusion with the inner circumferential portion of the receiving frame by rotating the lock fitting about the one axis, the lid Devices with a so-called locking mechanism that can prevent the body from rotating around the hinge mechanism are increasingly being used.

(Problem) However, in such a manhole cover device with a locking mechanism, the lock fitting has conventionally been simply rotatably supported with respect to the cover body, and the lock fitting has been supported with respect to the keyhole formed in the lock fitting. By inserting and rotating a predetermined rotating member corresponding to the shape of the keyhole, the locked state could be easily released, so even those who were not familiar with the structure of the lock mechanism could easily unlock it. However, there is a risk that the locked state may be released extremely easily, especially if a person actively tries to open the cover of the manhole cover device with malicious intent. It was hard to say that there were any.

(Solution) The present invention was made in view of the above circumstances, and its gist is that, as described above, the receiving frame is installed in a fixed position at the opening of a manhole. A lid body for opening and closing the opening of the receiving frame is attached via a predetermined hinge mechanism, and the opening of the receiving frame is opened and closed by rotation of the lid body around the hinge mechanism. A predetermined locking metal fitting is provided at a suitable position on the peripheral edge so as to be rotatable around an axis substantially perpendicular to the plate surface of the lid, and the locking metal fitting is further provided with an engagement that can be engaged with the inner peripheral part of the receiving frame. By forming a mating protrusion and engaging the engaging protrusion with the inner peripheral part of the receiving frame by rotating the lock fitting about the one axis, rotation of the lid body about the hinge mechanism is prevented. In the manhole cover device with a locking mechanism, a predetermined engaging portion is formed on the lock fitting, and a locking member capable of engaging with the engaging portion is rotatably provided around one axis, When the locking member is always biased in one rotational direction and the lock fitting is rotated to a rotational position where the engagement protrusion engages with the inner circumference of the receiving frame, the locking member is always biased in one rotational direction. A member is configured to engage with an engaging portion of the lock fitting to prevent rotation of the lock fitting around the one axis, and a member is provided at a predetermined position on the lid corresponding to the location where the locking member is disposed. The lock fitting of the locking member is formed by forming a through hole and forcibly rotating the locking member in a direction opposite to the urging direction by an operating force applied through the through hole. The lock fitting can be rotated about the one axis by releasing the engagement with the engagement portion of the lock fitting.

(Operation, Effect) According to such a manhole cover device, when the locking fitting is in the locking position of the cover,
As with conventional manhole cover devices with locking mechanisms, the locking fitting cannot be rotated simply by inserting the rotating member into the keyhole of the locking fitting.
The lock fitting can be rotated only when the locking member is rotated in a direction opposite to the biasing direction through the through hole formed in the lid.

In other words, if you know the mechanism that rotates the locking member in the opposite direction to the biasing direction, you can easily release the locked state with an extremely simple operation, but if you know such a mechanism, For those who do not have the locking function, they will not be able to release the lock unless they come up with the idea of rotating the locking member through the hole formed in the lid. The effect will be improved accordingly. Therefore, compared to the case of adopting a conventional manhole cover device with a lock, it is possible to improve the effectiveness of preventing unauthorized persons from entering the manhole. Inconveniences can be reduced.

(Example) Hereinafter, in order to clarify the present invention more specifically, one example thereof will be described in detail based on the drawings.

FIG. 1 shows an overall plan view of a manhole cover device with a double locking mechanism according to an embodiment of the present invention.
Further, FIG. 2 shows longitudinal sectional views of the main parts thereof. This manhole cover device has a receiving frame 12 in the form of a flat cylinder with a rectangular frame shape, and a lid body 14 that closes the opening of the receiving frame 12. It is now installed in a fixed position. The lid body 14 is adapted to be tapered fitted at its outer circumferential tapered surface 18 to an inner circumferential tapered surface 16 formed at the opening of the receiving frame 12, and in this tapered fitted state,
The opening of the receiving frame 12 is closed.

Moreover, as shown in FIG.
A pair of hinge mechanisms 20 (only one of which is shown here) is provided on one of the long sides between the lid body 14 and the lid body 14, and the lid body 14 rotates around these hinge mechanisms 20. It is designed to be able to move. The opening of the receiving frame 12 can be opened and closed by rotating the lid 14 around the hinge mechanism 20. Note that this hinge mechanism 20
has the same structure as the hinge mechanism disclosed in Japanese Utility Model Application Publication No. 61-89053, and is not necessarily essential for understanding the invention of the present invention, so a detailed explanation thereof will be omitted.

On the other hand, a pair of locking mechanisms 22 are provided between the receiving frame 12 and the lid 14 on the long side opposite to the side on which the hinge mechanism 20 is provided. The lid body 14 then locks these locking mechanisms 22.
This allows it to be held in the closed position shown.

These locking mechanisms 22 are shown in FIGS.
As shown in detail in the figure, a lock fitting 24 is rotatably supported by the lid 14, and a protrusion formed on the lower side of the inner circumferential tapered surface 16 of the receiving frame 12 and protruding inside the opening thereof. It consists of a section 26. The lock fitting 24 is a shaft member having a substantially cylindrical outer shape, and is disposed perpendicularly through the plate surface of the lid 14. locking plates 28, 28
It is supported so as to be rotatable about its axis and immovable in the axial direction. A keyhole 30 is formed in the center of the locking fitting 24, passing through it in the axial direction, and having a circular shape with a large diameter in the center and a longitudinal rectangular cross section. A predetermined rotating member 32
This allows the lock fitting 24 to rotate around its axis.

Further, at the lower end of the lock fitting 24, a locking pawl 34 as an engagement protrusion protrudes laterally.
is formed so that when the lock fitting 24 is rotated to a predetermined rotation position, the locking pawl 34 is engaged with the lower end of the protrusion 26 of the receiving frame 12.

Therefore, the rotating member 32 is inserted into the keyhole 30, and the lock fitting 24 is rotated by the rotating member 32 inserted into the keyhole 30, so that the locking claw 34 is engaged with the protrusion 26 of the receiving frame 12. If they are aligned, the lid body 14 can be prevented from rotating around the hinge mechanism 20, and conversely, the locking pawl 34 can be prevented from rotating around the hinge mechanism 20.
By rotating the lock fitting 24 to a rotation position where it does not engage with the locking member 6, the opening of the receiving frame 12 can be opened by rotating the lid 14 around the hinge mechanism 20.

The lock fitting 24 has a pair of circumferential grooves 35, 35 of a predetermined length, which are located approximately half a circumference apart in the circumferential direction on its outer circumferential surface. The locking plate 28,2
8 is adapted to be locked. The grooves 35, 35 can be rotated about their axes within a rotation range corresponding to the lengths of the grooves 35, 35. Further, a radially outward flange portion 36 is formed at the upper end of the locking metal fitting 24, and this flange portion 36 of the locking metal fitting 24 is accommodated in a counterbore hole 38 formed on the surface of the lid body 14. It is supported by the lid 14 in this state. Further, in FIGS. 3 and 4, reference numeral 39 indicates a rotation preventing protrusion for the rotation member 32 formed on the lower surface of the lock fitting 24, and in FIG.
It is a crowbar hole formed in.

By the way, the lock fitting 24 is inserted into its key hole 30.
If the manhole cover device can be freely rotated by the rotating member 32 inserted into the manhole cover device, it can be easily rotated even by a person who is not familiar with the structure of the locking mechanism, similar to the conventional manhole cover device with a locking mechanism. However, it is difficult to say that this method is desirable especially when used in a manhole, such as a gas manhole, which may cause serious problems because the locked state may be released very easily.

Therefore, in this embodiment, as shown in FIG. 3 and FIG. , an engagement hole 42 of a predetermined depth is formed as an engagement part, and is located on the back side of the lid 14 facing the protrusion 26 of the receiving frame 12 with the lock fitting 24 in between. A triangular locking member 44 is disposed at its lower end so as to be rotatable around a horizontal axis, and the locking member 44 is always urged counterclockwise in FIG. 3 by its own weight. There is. As shown in the figure, when the locking metal fitting 24 is rotated to the locking position where the locking pawl 34 engages with the protrusion 26 of the receiving frame 12, the locking member 44 is integrally formed with the locking member 44. Stop part 4
6 is an engagement hole 42 formed in the lock fitting 24.
It is designed to automatically rush inside.

When the lock fitting 24 is rotated to the rotational position where the locking pawl 34 engages with the protruding portion 26 of the receiving frame 12, the locking portion 46 of the locking member 44 engages the lock fitting 24 by its own weight. It is designed to automatically engage with the hole 42, and based on this engagement, the rotation of the lock fitting 24 is automatically prevented.

Further, the locking member 44 has a locking portion 46 at its upper portion.
The portion opposite to the side on which the
A through hole 5 that penetrates the front and back sides in a part corresponding to 8.
0 is formed. As a result, the through hole 5 formed in the lid body 14 is connected to the locking member 44.
0, it is possible to apply an operating force in the clockwise direction in FIG. The operating member 44 can be rotated in a direction opposite to the biasing direction through a through hole 50 formed in the lid 14, thereby locking the locking portion 46 of the operating member 44. 2
It is designed so that it can be removed from the engagement hole 42 of No. 4.

Therefore, in order to release the locked state of the locking mechanism 22, the locking member 4 is inserted through the through hole 50 of the lid 14.
4 in a direction opposite to the biasing direction (counterclockwise in FIG. 3), and in this state, the lock fitting 24 is rotated around its axis. If you do this,
Rotating the lid body 14 around the hinge mechanism 20,
This allows the opening of the receiving frame 12 to be opened.

As shown in FIGS. 3 and 4, the locking member 44 is made of stainless steel, which has excellent corrosion resistance and mechanical strength, with respect to the pair of arm portions 52 formed on the back surface of the lid body 14. It is rotatably attached by a steel pin 54.

Furthermore, as shown by the two-dot chain line in FIG.
The rotation end position in the direction opposite to the urging direction is restricted. As a result, as described above, the locking member 44 is always urged in the urging direction by its own weight.

According to the device of this embodiment, as described above,
When the locking pawl 34 of the locking metal fitting 24 is rotated to the locking position where it engages with the protrusion 26 of the receiving frame 12, the locking part 46 of the locking member 44 automatically engages with the engagement hole 42 of the locking metal fitting 24. Therefore, it is not possible to lock the manhole cover by simply inserting the rotating member 32 corresponding to the shape of the keyhole 30 of the locking fitting 24, as in the conventional manhole cover device with a locking mechanism. The metal fitting 24 cannot be rotated, and the through hole 5 formed in the lid body 14
The lock fitting 24 can be rotated only when the locking member 44 is rotated in the opposite direction to the biasing direction through the locking mechanism 0, that is, only when the operating portion 48 of the locking member 44 is pushed downward.

Therefore, as long as one knows the mechanism for rotating the locking member 44 in the direction opposite to the biasing direction, the locked state of the locking mechanism 22 can be released with an extremely simple operation as described above. However, for those who do not know such a mechanism, the locking member 4 can be inserted through the through hole 50 formed in the lid body 44.
Unless the user comes up with the idea of rotating the lock mechanism 22, the locked state of the lock mechanism 22 cannot be released.
Therefore, compared to the case of adopting a conventional manhole cover device with a locking mechanism, it is possible to improve the prevention effect against unauthorized persons entering the manhole. This can reduce the inconveniences that may occur.

One embodiment of the present invention has been described in detail above, but
This is a literal example, and it goes without saying that the present invention should not be construed as being limited to this specific example.

For example, in the embodiment described above, the locking member 44 is biased in the biasing direction by its own weight, but the locking member 44 is biased by a predetermined biasing member such as a spring. It is also possible to make it energized. However, from the viewpoint of maintenance and management, it is desirable that the locking member 44 be biased by its own weight, as in the device of the above embodiment.

Further, in the embodiment, the locking part 46 of the locking member 44 rotates upward to lock the lock fitting 2.
4, but it is also possible to separate from the engagement hole 42 by rotating the locking portion 46 downward. In addition, if you do this,
It is possible to form an engaging portion on the lower surface of the lock fitting 24.

Further, in the embodiment described above, rotation of the lock fitting 24 was allowed by pushing the operating portion 48 of the locking member 44 downward through the through hole 50 formed in the lid 14. It is also possible to allow the lock fitting 24 to rotate by pulling up the action portion 48 of the locking member 44 using a predetermined member inserted through the through hole 50 of the lid 14. . However, in this case,
For example, in FIG. 3, when the locking member 44 is rotated clockwise, the locking portion 46 locks into the lock fitting 2.
A structure that can be engaged with the engaging portion of No. 4 will be adopted. In addition, when a plurality of locking mechanisms 22 are arranged in parallel as in the device of this embodiment, the locking mechanism 22 may be of the type in which the action portion 48 of the locking member 44 is pushed downward as in the embodiment described above, or the type in which the action portion 48 of the locking member 44 is pushed downward as in the embodiment described above. It is possible to use it in appropriate combination with a type that pulls up upwards, such as.

Although not listed in detail, it goes without saying that the present invention can be implemented with various changes, modifications, improvements, etc. without departing from the spirit thereof.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing an example of a manhole cover device according to the present invention, and FIG. 2 is a sectional view thereof. FIG. 3 is an enlarged sectional view of the main part of FIG. 2, and FIG. 4 is a partially cutaway bottom view thereof. 12... Receiving frame, 14... Lid body, 20... Hinge mechanism, 22... Lock mechanism, 24... Lock metal fitting,
26... Protrusion part, 30... Keyhole, 34... Locking claw (engaging protrusion), 42... Engaging hole (engaging part), 44...
...Locking member, 46...Locking part, 48... Acting part,
50...Through hole.

Claims (1)

[Claim for Utility Model Registration] A lid body for opening and closing the opening of the receiving frame is attached to a receiving frame installed in a fixed position at the opening of a manhole via a predetermined hinge mechanism, and the hinge mechanism of the lid body While the opening of the receiving frame is opened and closed by rotation, a predetermined locking metal fitting is positioned at a suitable position on the periphery of the lid body and is rotated in a direction substantially perpendicular to the plate surface of the lid body. Further, the lock fitting is provided with an engaging protrusion capable of engaging with the inner circumferential portion of the receiving frame, and the engaging protrusion is rotated by rotation of the lock fitting around the one axis. In the manhole cover device with a locking mechanism that can prevent the lid from rotating around the hinge mechanism by engaging with the inner circumferential portion of the receiving frame, a predetermined engagement portion is formed on the lock fitting. At the same time, a locking member capable of engaging with the engaging portion is rotatably provided around one axis, and the locking member is always biased in one rotational direction so that the locking member engages with the engaging protrusion. When the locking member is rotated to the rotational position where it engages with the inner peripheral portion of the receiving frame, the locking member engages with the engaging portion of the locking metal fitting and prevents the locking metal fitting from rotating around the one axis. On the other hand, a predetermined through hole is formed in the lid body corresponding to a location where the locking member is disposed, and an operating force applied through the through hole causes the locking member to be blocked. By forcibly rotating the locking member in a direction opposite to the biasing direction, the engagement of the locking member with the engaging portion of the locking fitting is released, and the locking fitting can be rotated around the one axis. A manhole cover device with a double locking mechanism.