JP3992154B2 - Locking device for manhole cover - Google Patents

Description

The present invention relates to a lid locking device provided in a manhole which is an entrance of a communication cable, a power transmission cable, a common groove for storing a water and sewage pipe, and the like.

A conventional manhole cover locking device includes a fixed outer cylinder that is fixed to a manhole cover with a central axis arranged in the vertical direction; a movable inner cylinder that is rotatably and vertically movable inserted into the fixed outer cylinder; A lock shaft having an upper end inserted into and connected to the movable inner cylinder, and a lower portion protruding from the fixed outer cylinder; a stopper metal fixed to a lower portion of the lock shaft and engaged with and disengaged from a receiving portion of a manhole outer frame; By rotating the movable inner cylinder by a predetermined angle with a lock operation tool, the lock shaft is rotated to the locked position or the unlocked position while moving in the vertical direction (see Patent Document 1).

However, in this conventional apparatus, the movable inner cylinder is in the inner space of the fixed outer cylinder regardless of whether the clasp is in the unlocked position or the locked position, so that it is possible to distinguish between the locked state and the unlocked state. It has been reported that there are not a few cases in which the manhole cover is fitted to the manhole outer frame and then forgot to lock and leave.

Japanese Patent Laid-Open No. 2-88821

An object of the present invention is to provide a locking device for a manhole cover that can reduce the risk of leaving the manhole cover in an unlocked state because the locked state and the unlocked state can be clearly determined depending on whether the cap is tightened or not. That is.

The locking device for a manhole cover according to the present invention includes a fixed outer cylinder 4 which is fixed to the manhole cover 1 with a central axis arranged in the vertical direction, and has a female screw portion 3 formed on the inner peripheral surface of the upper end opening 2;
A movable inner cylinder that is inserted into the fixed outer cylinder 4, is prevented from rotating with respect to the fixed outer cylinder 4, and can move only in the vertical direction, and has a helical cam groove 5 formed around the central axis on the lower cylinder wall 6 and
The upper half portion is inserted into the lower end portion of the movable inner cylinder 6 from the lower end opening 7 of the fixed outer cylinder 4, is rotatable with respect to the fixed outer cylinder 4, and is prevented from moving in the vertical direction. A drive shaft 8 inserted into the cam groove 5 on the side surface, and a lock shaft 12 provided with a passive portion 11 engaged with the drive portion 10 of the lock operating tool 9 on the upper end surface;
A detent 15 that is fixed to the lower half of the lock shaft 12 protruding from the fixed outer cylinder 4 and is engaged with and disengaged from the receiver 14 of the manhole outer frame 13;
A cap 19 that is screwed into the upper end opening 2 of the fixed outer cylinder 4 and provided with a passive portion 18 that engages with the drive portion 17 of the cap operating tool 16 on the upper end surface;
When the cap 19 is removed from the fixed outer cylinder 4 by the cap operation tool 16 and the lock shaft 12 is turned to the unlocked position by the lock operation tool 9, the movable inner cylinder 6 rises into the upper end opening 2 of the fixed outer cylinder 4. It is what I did.

In the manhole cover locking device of the present invention, the cap 19 is engaged with the passive portion 18 of the cap 19 and the cap 19 is rotated in a predetermined direction, whereby the cap 19 is opened at the upper end of the fixed outer cylinder 4. Then, the locking member 15 is engaged with the passive portion 11 of the lock shaft 12 and the lock shaft 12 is rotated in a predetermined direction so that the stopper 15 is attached to the manhole outer frame 13. In this unlocked position, the movable inner cylinder 6 is moved by the cooperative action of the cam groove 5 of the movable inner cylinder 6 and the drive projection 8 of the lock shaft 12. Since the movable inner cylinder 6 has moved up and entered the upper end opening 2 of the fixed outer cylinder 4, the male screw portion 28 of the cap 19 is attached to the female screw portion 3 of the upper end opening 2 in the unlocked state. Screwed onto the cap 19 There can not tighten the cap 19 sufficiently to a position aligned with the upper surface of the manhole cover 1. As described above, since the locked state and the unlocked state can be clearly determined depending on whether the cap 19 is tightened or attached, the risk of leaving the manhole cover 1 in the unlocked state can be reduced.

In the embodiment shown in FIGS. 1 to 16, a dummy lock 20 is inserted into the cavity between the cap 19 of the fixed outer cylinder 4 and the lock shaft 12. This dummy lock 20 is. At first glance, the form of the upper surface portion that can be seen when the cap 19 is removed looks like a real lock, and does not have a lock function in a normal sense.

The dummy lock 20 functions as an interlocking member that transmits the rotational force of the lock operating tool 9 to the lock shaft 12. The round shaft portion 21 on the upper portion of the dummy lock 20 has the same configuration as the passive portion 18 of the cap 19. The passive portion 22 is provided on the upper surface portion. The passive portion 18 of the cap 19 and the passive portion 22 of the dummy lock 0 are obtained by arranging a cylindrical portion at the center of the oval recess.
The lower portion of the dummy lock 20 is a square shaft portion 23 having a hexagonal cross section, and is fitted into the hexagonal passive portion 11 of the lock shaft 12.

A waterproof ring 25 is attached to the outer peripheral surface groove 24 of the cap 19, and a waterproof ring 27 is fitted into the outer peripheral surface groove 26 of the round shaft portion 21 of the dummy lock 20. On the outer peripheral surface of the cap 19, a male screw portion 28 that is screwed into the female screw portion 3 of the fixed outer cylinder 4 is formed below the waterproof ring 25.

The drive protrusion 8 of the lock shaft 12 is constituted by a pin driven into the outer peripheral surface hole 30 of the large-diameter head portion 29 of the lock shaft 12, and two drive protrusions 8 are provided in the diameter direction of the lock shaft 12. Correspondingly, two cam groove portions 5 of the movable inner cylinder 6 are provided symmetrically with respect to the central axis. As shown in FIG. 1, when the lock shaft 12 is in the locking position, the drive protrusion 8 is engaged with the upper end portion of the cam groove portion 5. In this locking position, the movable inner cylinder 6 is at the lowest position, and the upper end surface of the movable inner cylinder 6 is at a position where it has escaped downward from the upper end opening 2 of the fixed outer cylinder 4.

The fixed outer cylinder 4 is non-rotatably fitted in the vertical receiving hole 31 of the manhole cover 1 and is fastened and fixed to the manhole cover 1 by a nut 33 screwed into the lower end female screw portion 32. A guide groove 34 in the vertical direction is formed on the inner peripheral surface of the upper half portion of the fixed outer cylinder 4, and the regulation protrusion 35 on the outer peripheral surface of the movable inner cylinder 6 is engaged with the guide groove 34, thereby The cylinder 6 is prevented from rotating with respect to the fixed outer cylinder 4 and is movable in the vertical direction.

The male screw portion 36 in the lower half portion of the lock shaft 12 passes through the vertical hole 37 in the main portion of the clasp body 15, and the clasp body 15 is locked by the nut 38 screwed into the male screw portion 36. It is connected to the. A detent pin 39 is driven in the transverse direction in the detent body 15, and the tip of the detent pin 39 is abutted against the side flat portion 42 of the lock shaft 12. To prevent idling.
The lock shaft 12 is restricted from moving in the vertical direction by a large-diameter head portion 29 that abuts against the inner bottom wall 40 of the fixed outer cylinder 4 and a stopper body 15 that faces the lower end surface of the fixed outer cylinder 4. . In the center of the lock shaft 12, a drainage port 5 penetrates vertically.

As shown in FIG. 4, when the lock shaft 12 is rotated in a direction in which the stopper body 15 is detached from the metal receiving portion 14 of the manhole outer frame 13, the cam groove portion 5 of the movable inner cylinder 6 and the drive protrusion of the lock shaft 12. The movable inner cylinder 6 is raised by the cooperative action of 8. In this unlocked position, the drive protrusion 8 is engaged with the lower end portion of the cam groove portion 5, and the movable inner cylinder 6 is in the most elevated position and enters the upper end opening 2 of the fixed outer cylinder 4. Therefore, by screwing the male screw portion 28 of the cap 19 into the female screw portion 3 of the upper end opening 2, the cap 19 cannot be tightened to the position where the upper surface of the cap 19 is aligned with the upper surface of the manhole cover 1.

In the above embodiment, even after the cap 19 is removed, the dummy lock 20 remains in the fixed outer cylinder 4 and is used as an interlocking member, so that the cap operation tool 16 is used as it is as the lock operation tool 9.
When the dummy lock 20 is removed from the fixed outer cylinder 4, a lock operating tool 9 having a drive unit 10 in a form adapted to the passive unit 11 of the lock shaft 12 is prepared separately. In that case, the lock operating tool 9 and the cap operating tool 16 can be configured as a single body, such as both ends of one bar.

In the embodiment shown in FIGS. 17 to 19, the dummy lock 20 in the above embodiment is replaced with a real lock unit 41 having a normal lock function. Since the other configuration is the same as that of the above embodiment, the detailed description is omitted.
After the cap 19 is removed from the upper end opening 2 of the fixed outer cylinder 2, the lock unit 41 is released from the restriction on the fixed outer cylinder 4 by inserting a corresponding key from the upper end opening 2. It is taken out from. In the upper part of the fixed outer cylinder 4, a regulating groove 43 is formed in the vertical direction in the middle part of the pair of guides 34. A regulation pin 44 protruding from the outer peripheral surface of the lock unit 41 is engaged with the regulation groove 43, thereby preventing the lock unit 41 from idling relative to the fixed outer cylinder 4.

After removing the lock unit 41 from the fixed outer cylinder 4, the lock operating tool 9 is inserted into the fixed outer cylinder 4 from the upper end opening 2, and the drive unit 10 of the lock operating tool 9 is directly engaged with the passive part 11 of the lock shaft 12. As a result, the lock shaft 12 is rotationally driven in the locking direction or the unlocking direction.

As shown in FIG. 19, when the lock shaft 12 is rotated in the direction in which the stopper body 15 is detached from the metal receiving portion 14 of the manhole outer frame 13, the cam groove portion 5 of the movable inner cylinder 6 and the drive protrusion of the lock shaft 12. The movable inner cylinder 6 is raised by the cooperative action of 8. In this unlocked position, the drive protrusion 8 is engaged with the lower end portion of the cam groove portion 5, and the movable inner cylinder 6 is in the most elevated position and enters the upper end opening 2 of the fixed outer cylinder 4. Therefore, by screwing the male screw portion 28 of the cap 19 into the female screw portion 3 of the upper end opening 2, the cap 19 cannot be tightened to a position where the upper surface of the cap 19 is aligned with the upper surface of the manhole cover 1.

In this example, the lock operating tool 9, the cap operating tool 16, and the keys of the lock unit 41 can be configured as a single T-shape instead of being configured separately.

It is a longitudinal cross-sectional view in the locking state of the locking device for manhole covers concerning one Example of this invention. It is a top view of the locking device of FIG. It is a top view when the cap of the locking device of FIG. 1 is removed. It is a longitudinal cross-sectional view of the unlocking state of the locking device of FIG. It is a top view of the cap used for the locking device of FIG. It is a longitudinal cross-sectional view of the cap of FIG. It is a top view of the movable inner cylinder used for the locking device of FIG. It is a longitudinal cross-sectional view of the movable inner cylinder of FIG. It is a bottom view of the movable inner cylinder of FIG. It is a left view of the movable inner cylinder of FIG. It is a top view of the dummy lock used for the locking device of FIG. It is a front view of the dummy lock of FIG. It is a bottom view of the dummy lock of FIG. It is a top view of the lock shaft used for the locking device of FIG. It is a front view of the lock shaft of FIG. It is a bottom view of the lock shaft of FIG. It is a longitudinal cross-sectional view in the locking state of the locking device for manhole covers based on another Example of this invention. It is a top view of the locking device of Drawing 17, and shows the state where a cap and a lock unit were removed. It is a longitudinal cross-sectional view of the unlocking state of the locking device of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manhole cover 2 Upper end opening part of fixed outer cylinder 3 Female screw part 4 of upper end opening part Fixed outer cylinder 5 Cam groove part of movable inner cylinder 7 Movable inner cylinder 7 Lower end opening part of fixed outer cylinder 8 Drive protrusion 9 of a lock shaft Operation tool 10 Drive part 11 of lock operation tool Passive part 12 of lock shaft 12 Lock shaft 13 Manhole outer frame 14 Receiving part 15 Clasp body 16 Cap operation tool 17 Drive part 18 of cap operation tool Passive part 19 of cap 19 Cap 20 Dummy Lock 21 Round shaft portion of dummy lock 22 Passive portion of dummy lock 23 Square shaft portion of dummy lock 24 Cap outer peripheral groove 25 Cap waterproof ring 26 Dummy lock outer peripheral groove 27 Dummy lock waterproof ring 28 Male screw portion 29 Large-diameter head portion 30 of the lock shaft Outer peripheral surface hole 31 of the large-diameter head portion Vertical receiving hole 32 of the manhole cover Female screw portion 33 at the lower end of the fixed outer cylinder Fixed nut 34 for fixing the fixed outer cylinder Guide groove 35 of the fixed outer cylinder Restricting protrusion 36 of the movable inner cylinder 36 Male screw part 37 of the lock shaft Vertical hole 38 of the metal stopper body Fixing nut 39 of the metal stopper body Locking pin 40 of the metal stopper body Inner bottom of the fixed outer cylinder Wall 41 Lock unit 42 Side flat part 43 of lock shaft Restriction groove 44 of fixed outer cylinder Locking pin of lock unit 45 Drainage hole of lock shaft

Claims (1)

A fixed outer cylinder 4 which is fixed to the manhole cover 1 with the central axis line arranged in the vertical direction and has a female screw part 3 formed on the inner peripheral surface of the upper end opening 2;
A movable inner cylinder that is inserted into the fixed outer cylinder 4, is prevented from rotating with respect to the fixed outer cylinder 4, and can move only in the vertical direction, and has a helical cam groove 5 formed around the central axis on the lower cylinder wall 6 and
The upper half portion is inserted into the lower end portion of the movable inner cylinder 6 from the lower end opening 7 of the fixed outer cylinder 4, is rotatable with respect to the fixed outer cylinder 4, and is prevented from moving in the vertical direction. A drive shaft 8 inserted into the cam groove 5 on the side surface, and a lock shaft 12 provided with a passive portion 11 engaged with the drive portion 10 of the lock operating tool 9 on the upper end surface;
A detent 15 that is fixed to the lower half of the lock shaft 12 protruding from the fixed outer cylinder 4 and is engaged with and disengaged from the receiver 14 of the manhole outer frame 13;
A cap 19 that is screwed into the upper end opening 2 of the fixed outer cylinder 4 and provided with a passive portion 18 that engages with the drive portion 17 of the cap operating tool 16 on the upper end surface;
When the cap 19 is removed from the fixed outer cylinder 4 by the cap operation tool 16 and the lock shaft 12 is turned to the unlocked position by the lock operation tool 9, the movable inner cylinder 6 rises into the upper end opening 2 of the fixed outer cylinder 4. A manhole cover locking device.

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