JP3995809B2 - Manhole cover locking device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a locking device that locks a manhole cover to a manhole frame so that the cover plate of the manhole does not jump up or off or is opened by an outsider.
[0002]
[Prior art]
The manhole is a vertical hole connected to a horizontal hole for sewer and cable wiring provided in the ground, and a manhole cover is provided at the ground surface at the upper end of the vertical hole. This vertical hole is formed by a concrete manhole block, and a cast iron manhole frame is usually fixed to the upper end of the manhole block, and the manhole cover is fixed in a state of being fitted into the manhole frame. The manhole cover needs to be firmly fixed so that it does not rattle or rainwater enters from around the cover. Therefore, usually, the manhole cover is mounted by fitting the conical surfaces formed on the inner periphery of the upper end of the manhole frame and the outer periphery of the manhole cover.
[0003]
Since the manhole cover is mounted in such a structure, the manhole cover usually does not rattle or come off. However, there is a risk that the manhole cover will spring up or come off when the manhole is filled with gas and internal pressure is applied.If an outsider can easily open the manhole cover, the manhole cover may be tampered with. There is a risk that a person or an object may be dropped into the manhole and a cable or the like disposed in the underground hole may be damaged. Therefore, a lock device is provided on the manhole cover so that the manhole cover is not opened.
[0004]
The manhole cover locking device does not need to have a complicated structure like the door locking device of automobiles or safes, and is often left unattended for a long period of time, so it has a simple structure with excellent durability. Is desirable. Normally, this locking device has a manhole cover that is attached to a flange or a downward step provided on the inner side of the manhole frame by projecting a claw or tongue piece provided on the back side of the manhole cover to the outer periphery. It is a structure that prevents it from coming off the manhole frame. A structure in which the lock piece (claw or tongue piece) is advanced and retracted by rotating the operation pin provided on the manhole cover is often used. The lock piece is fixed to the lower end of the operation pin, and the operation pin is rotated. A structure in which the lock piece moves forward and backward by swinging an arc when moved, a structure in which the lock piece is connected to an operation pin via a link, and a plurality of lock pieces move synchronously when the operation pin is rotated, etc. Has been advocated.
[0005]
[Problems to be solved by the invention]
Locking device manhole cover as described above, but can be of various structures, the pressure when the pressure in the manhole is increased a function of the air release, the lock piece is not saved by vibration or the like The structure also requires that outsiders cannot be easily unlocked, that people trapped in the manhole can unlock from the bottom of the manhole cover, and that the structure is simple and does not require maintenance. Therefore, the various lock structures provided in the past have not always been satisfactory.
[0006]
[Means for Solving the Problems]
The inventions, the flange inner forming the lock piece 11 mounted on the lower surface of the manhole cover having a conical outer peripheral surface to be fitted in a conical surface formed on the upper end inside of the manhole frame 1 in the inner periphery of the upper end of the manhole frame Or in the locking device which advances below the stepped portion 3 to prevent the opening of the manhole cover, the upper end portion penetrating the manhole cover 4 up and down is inserted into the stepped through hole 6 having a large diameter and the stepped through hole. Elasticity between the operation pin 8 having the large-diameter head 7 provided with a tool insertion recess 15 having directionality at the upper end, and the step 6a of the stepped through hole and the large-diameter head 7 of the operation pin A rubber ring 10 that is sandwiched in a compressed state, a lock piece 11 having a protrusion or a notch on an upward surface fixed to the lower end of the operation pin so as not to be relatively rotatable, and a stepped penetration in the lower surface of the manhole cover Of the locking piece around the hole And a so provided notched portion or projection for part or the notch part and the fitting, there is provided a locking device for the manhole cover.
[0007]
In the present invention, the manhole cover 4 is further provided with an opening 19 for communicating the upper end large diameter portion 6b of the stepped through hole with the lower surface of the cover, and the operation pin 8 is provided with the tool insertion recess 15 and the large diameter head 7. A manhole cover locking device having a structure in which a groove 20 communicating with the surroundings is provided . As a more preferable structure of the locking device having the above structure, the tool insertion recess 15 provided at the upper end of the large-diameter head 7 of the operation pin has an arrow shape, and the lock piece 11 is fixed to the direction of the arrow and the lower end of the operation pin. We propose a structure that matches the extending direction.
[0008]
[Action]
An operator who opens and closes the manhole cover that is mounted by fitting the conical surfaces with each other normally uses a bar to open the manhole cover that is tightly fitted using the boost due to the lever action. . In the structure of the present invention, if a projecting piece having a cross-sectional shape that matches the cross-sectional shape of the tool insertion recess formed on the upper surface of the large-diameter head of the operation pin is welded to the end of the bar, the projecting piece is attached to the manhole. Inserted into the large-diameter head of the operating pin of the lid, pushed down from above and further elastically compressed the rubber ring 10 to move the operating pin 8 slightly downward, so that the protrusion or notch of the lock piece and the step The fitting with the notches or protrusions around the attached through hole is removed, and the bar is rotated in this state, so that the lock piece is advanced or retracted to lock and release.
[0009]
If the tool insertion recess has a special cross-sectional shape, it is an operation that compresses the rubber ring 10 and rotates it under the frictional force. It is very difficult to do so, thus preventing outsiders from opening the manhole cover unnecessarily.
[0010]
The rubber-like elastic ring 10 is locked naturally by vibration or the like by maintaining the fitting between the protrusion or notch of the lock piece and the notch or protrusion around the stepped through hole by the elasticity to be restored. to prevent the piece 11 is retracted, also exerts three types of actions that you tight seal between the giving some resistance to rotation of the operation pin as described above, further manipulation pin and stepped through hole Yes.
[0011]
The lock piece 11 fixes the lock piece 11 at the advanced position by fitting the protrusion or notch with the notch or protrusion around the stepped through hole 6. The opening 19 and the groove 20 allow the earth and sand accumulated around the tool insertion recess 15 and its surroundings to flow out into the manhole together with rainwater, and can save time and labor for removing earth and sand when the lid is opened.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 through 4, illustrating the embodiment of the present invention. The manhole frame of FIG. 1 includes an outer frame fixed to a manhole block, and an inner frame 1 fitted in the outer frame so as to be tiltable up and down. An inner peripheral surface 2 is formed, and a downward step surface 3 is formed immediately below the inner peripheral surface 2.
[0013]
The manhole cover 4 is made of cast iron and has a conical outer peripheral surface 5 that fits into the conical inner peripheral surface 2. Stepped through-holes 6 penetrating in the vertical direction are provided at two positions close to the outer periphery of the manhole cover 4 (only one position is shown in the figure). The stepped through hole 6 is a circular hole 6b having a large diameter at the upper end, and an upward step surface 6a is formed at a portion where the diameter changes. A portion around the stepped through hole 6 on the lower surface of the manhole cover 4 slightly protrudes downward.
[0014]
An operation pin 8 having a large-diameter head 7 at the upper end is inserted into the stepped through hole 6. At the tip of the operation pin 8, there is a short oval projection 13 whose width between the two surfaces is smaller than the diameter, and a screw hole 9 is provided at the tip axis. The operation pin is formed by inserting a ring 10 formed of synthetic rubber such as urethane rubber under the neck of the large-diameter head 7 and inserting the ring 10 into the stepped through-hole 6. Is installed. The lock piece 11 is provided with a shallow notch groove 12 at the center of the upper surface thereof, and this groove is fitted with a short oval projection 13 at the tip of the operation pin 8 to prevent relative rotation of the lock piece with respect to the operation pin. ing.
[0015]
On the other hand, as shown in FIG. 3, radial cutout grooves 14 are provided on both sides of the lower surface of the manhole cover 4 around the stepped through hole 6 so as to sandwich the stepped through hole. When the lock piece 11 faces outward in the radial direction, the bank-like protrusions 16 on both sides in the width direction of the upper surface of the lock piece are fitted into the notch grooves 14 so that the lock piece 11 faces outward, that is, advances. Keep state.
[0016]
Ring 10 interposed rubber quality between the large diameter head 7 of the step surface 6a and the operation pin of the stepped through-hole 6, Ri Contact is slightly crushed state, the operation pin 8 It is biased upward so that the fitting between the lock piece 11 and the notch groove 14 is not released. The retracted position of the lock piece 11 is a position rotated about 90 degrees from the advanced position, and the stopper 17 for preventing the lock piece 11 from rotating excessively from this position is stepped through so that the stopper 17 abuts on the protrusion 16 of the lock piece 11. Projects to the bottom of the hole.
[0017]
FIG. 1 shows a partial cross-section when the lock piece has advanced, between the top surface of the advanced lock piece and the downward step surface 3 that engages with the lock piece provided on the manhole frame. There is a certain gap. When the manhole is filled with gas, the manhole cover is lifted by the gap due to the internal pressure, a gap is opened on the conical fitting surface, and the pressure in the manhole is released.
[0018]
An arrow-shaped recess 15 as shown in FIG. 2 is formed on the upper surface of the large-diameter head 7 of the operation pin, and a projecting piece having a cross-sectional shape that is just inserted into this recess is used for opening and closing the manhole. Weld on the end of the bar. When the projecting piece attached to the bar from the closed state of FIG. 2 is inserted into the arrow-shaped recess 15 and the bar is pushed down, the rubber ring 10 is compressed and the operation pin 8 moves downward, and the projecting part of the locking piece The fitting between the strip 16 and the notch groove 14 around the stepped through hole is released. If the bar 11 is rotated while being pressed, the lock piece 11 is rotated around the operation pin 8 and retracted from the downward step surface 3 of the manhole frame as shown by a two-dot chain line in FIG. As in the case of opening a normal manhole cover, the bar is hooked on a hook of a manhole frame (not shown), and the manhole cover is opened using a lever action.
[0019]
When closing the manhole cover, after inserting the manhole cover into the manhole frame, the bar protrusion is inserted into the arrow-shaped recess and the operation pin is rotated. When the lock piece advances and enters under the downward step portion 3 of the manhole frame, the protrusion 16 of the lock piece and the notch groove 14 around the step hole are fitted, and the elasticity of the rubber ring 10 The advance state is maintained. At this time, the arrow-shaped recess 15 can be confirmed from the outside that the arrow points radially outward and the lock piece is in the advanced state.
[0020]
FIG. 4 is a cross-sectional view of a sewer locking device that does not require airtightness. The tool insertion recess at the upper end of the operation pin 8 and the earth and sand accumulated around it are placed at the upper end large diameter portion 6b of the stepped through hole 6 of the lid 4. This is an embodiment in which it is made to flow out into the manhole together with rain water from the open port 19 connected to, and the trouble of removing earth and sand when the lid is opened is omitted. The tool insertion recess, to the surrounding atmospheric diameter head 7 from the recess as shown in FIG. 2 sediment, provided on the operation pin guide groove 20 exiting the water.
[Brief description of the drawings]
[1] lock piece plan view cross-sectional side view of FIG. 3] FIG. 1 cross-sectional front view Figure 2 Figure 1 of the locking device in a state doing business [4] water into the manhole interior, sediment Cross-sectional front view of the locking device that flows out
1 Manhole frame 3 Step 4 Manhole cover 6 Stepped through hole
6a Step part of stepped through hole 7 Large diameter head 8 Operation pin
10 rings
11 Lock piece
15 Tool insertion recess

Claims (2)

An inner flange formed on the inner periphery of the upper end of the manhole frame or a lock piece (11) mounted on the lower surface of the manhole cover having a conical outer peripheral surface that fits into a conical surface formed inside the upper end of the manhole frame (1) In the locking device that advances under the stepped downward section (3) to prevent the opening of the manhole cover,
A stepped through hole (6) having a large diameter upper end passing through the manhole cover (4) up and down and a tool insertion recess (15) having directionality are provided at the upper end inserted through the stepped through hole. The operation pin (8) having the large-diameter head (7), and the rubber sandwiched in an elastically compressed state between the step portion (6a) of the stepped through hole and the large-diameter head (7) of the operation pin A quality ring (10), a lock piece (11) having a protrusion or notch on the upward surface fixed to the lower end of the operation pin so as not to rotate relative to the lower end of the operation pin, and a stepped through hole around the lower surface of the manhole cover An opening (19 ) that communicates the notch or projection provided in the portion with the projection or notch of the lock piece and the upper end large diameter portion (6b) of the stepped through hole and the lower surface of the lid. ) and the tool insertion recess of the operating pin (15) and a periphery of the large-diameter head (7) and a groove (20) communicating with the locking device of the manhole cover. An arrow-shaped tool insertion recess (15) is provided at the upper end of the large-diameter head (7) of the operation pin, and the direction of this arrow coincides with the extending direction of the lock piece (11) fixed to the lower end of the operation pin. The manhole cover locking device according to claim 1, wherein

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