JP2014222307A - Sealing implement - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing implement which is reduced in the number of part items while holding a function to be surely broken when released from a sealing screw, and reduces a physical constitution.SOLUTION: A sealing implement 101 used in a power meter comprises a cylinder part 21 which is integrally formed of a resin material, and constitutes an outline; an inclined wall part 22, a ceiling part 23, a locking claw 33 which is arranged inside the cylinder part 21, and so forth. When attaching the sealing implement 101 to a head 71 of a sealing screw 7, the locking claw 33 is locked to a locking groove 73 of the sealing screw 7. When removing the sealing implement 101 from the head 71 of the sealing screw 7, it is difficult to grip the inclined wall part 22 formed at an upper part of the cylinder part 21 due to the slippage of a tool. Therefore, the locking claw 33 cannot be removed from the locking groove 73 by deforming a suspension part 32 by warping the ceiling part 23 by gripping only the upper part, and it becomes necessary to grip an outer wall of the cylinder part 21 by applying a relatively-large force thereto by inserting pincers 9 into the depth of the outer wall of the cylinder part 21. As a result, the sealing implement 101 can be surely broken.

Description

  The present invention relates to a sealing tool that covers a head of a sealing screw screwed to a sealing object such as a power meter.

  Conventionally, in a meter such as a wattmeter, in order to prevent unauthorized acts by a person other than a regular worker, the sealing screw screwing the cover and the case is screwed on the head of the sealing screw so that it cannot be operated from the outside. A sealing tool to be attached is known (for example, see Patent Document 1). When a regular worker performs repairs or inspections of the power meter or the like, the sealing tool is sandwiched between tools such as pliers, and then the sealing screw is removed and the cover is opened. Regular workers have replacement seals, and after work, attach new seals to the seal screws. Therefore, when the sealing tool is still destroyed, it is assumed that the power meter may have been opened illegally by a person other than a regular worker.

Japanese Utility Model Publication No. 60-27412

  The sealing tool disclosed in Patent Document 1 can be reliably broken when removed from the sealing screw, and is effective for early detection and prevention of fraud. However, it is composed of three members: a main body, a cap, and a locking spring, and has a large number of parts. Moreover, since the space for joining members is required, the physique is comparatively large.

  The present invention has been made in view of the above-mentioned problems, and its purpose is to provide a sealing device that reduces the number of parts and reduces the physique while retaining the function of being reliably destroyed when removed from the sealing screw. It is to provide.

The present invention relates to a sealing tool that can be attached to the head of a sealing screw so that the sealing screw screwed to the sealing object cannot be operated from the outside, and is destroyed when removed from the sealing screw.
The sealing tool of the present invention is formed integrally and includes a cylinder part, a locking claw, a ceiling part, and an inclined wall part.
The cylinder part can be inserted with the head of the sealing screw. The locking claw is provided on the inner side of the cylindrical portion, and locks in a locking groove formed on the side surface of the head of the sealing screw when the sealing tool is attached to the sealing screw. A ceiling part is provided in one side of the axial direction of a cylinder part, and when the said sealing tool is attached to a sealing screw, it shields the work groove formed in the head top surface of a sealing screw. The inclined wall portion connects one end of the cylindrical portion and the peripheral edge of the ceiling portion, and is inclined inward from the cylindrical portion toward the ceiling portion.

When the sealing tool of the present invention is attached to the head of the sealing screw, the locking claw is locked in the locking groove of the sealing screw. When an attempt is made to grasp the sealing tool with a tool such as pliers to remove the sealing tool from the head of the sealing screw, the inclined wall portion formed on the upper portion of the cylindrical portion is difficult to grasp because the tool slides.
If the sealing tool does not have an inclined wall part and only the upper part of the cylinder part can be gripped with a relatively small force by a tool, the ceiling part bends and the suspension part connects the ceiling part and the locking claw. However, by deforming so as to escape in the radially outward direction with the root as a fulcrum, there is a possibility that the locking claw will come off from the locking groove of the sealing screw, and the sealing tool may be removed from the sealing screw without being destroyed.
On the other hand, in the present invention, since it becomes difficult to grip the upper part of the cylindrical part with a tool by providing the inclined wall part, it is not possible to deform the suspension part by bending the ceiling part and remove the locking claw from the locking groove. Can not. Therefore, it is necessary to insert the tool all the way into the outer wall of the cylinder part and apply a relatively large force to grip the outer wall of the cylinder part. As a result, the sealing tool can be reliably destroyed.

  Since the sealing tool of the present invention is composed of one resin part, the number of parts can be reduced as compared with the sealing tool of the prior art composed of three members. Moreover, since the space for joining members becomes unnecessary, a physique can be made small.

  Furthermore, it is preferable that an uneven portion is formed on the outer wall of the cylindrical portion. Thereby, when a regular worker works, it becomes easy to hold a cylinder part by hand. In this case, the concavo-convex portion may be a longitudinal rib parallel to the central axis, or a lateral rib perpendicular to the central axis.

It is the (a) front view of the sealing tool by 1st Embodiment of this invention, (b) Axial direction sectional drawing (Ib-Ib sectional view taken on the line of FIG. 2). It is II arrow directional view (plan view) of FIG. It is a III arrow directional view (bottom view) of FIG. It is the (a) partial front view of the wattmeter to which the sealing tool by 1st Embodiment of this invention is applied, (b) It is a bottom view. It is the VV sectional view taken on the line of FIG. 4A which shows the state which attached the sealing tool by 1st Embodiment of this invention to the sealing screw. It is explanatory drawing which shows the state which hold | gripped the sealing tool by 1st Embodiment of this invention with pliers. It is explanatory drawing explaining the effect | action of a latching claw when the upper part of the sealing tool of a comparative example is grasped with pliers. It is explanatory drawing explaining the effect | action of the latching claw when the upper part of the sealing tool by 1st Embodiment of this invention is grasped with pliers. It is a schematic diagram which shows the state by which the sealing tool by 1st Embodiment of this invention was destroyed. It is a front view of the sealing tool by (a) 2nd, (b) 3rd embodiment of this invention. It is explanatory drawing which shows the state which hold | gripped the sealing tool by 2nd Embodiment of this invention with pliers. It is sectional drawing which shows the state which attached the sealing tool of the prior art to the sealing screw.

Hereinafter, sealing tools according to a plurality of embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
The structure of the sealing tool by 1st Embodiment of this invention is demonstrated with reference to FIGS. 1-3.
The sealing tool 101 is integrally formed of an opaque resin material such as ABS. Hereinafter, the vertical direction of FIG. 1 is referred to as “upper” and “lower” as appropriate, with the mounting state of the sealing tool 101 shown in FIG. 1 as a reference. A direction parallel to the central axis O of the cylindrical portion 21 is referred to as a “vertical direction”, and a direction orthogonal to the central axis O is referred to as a “lateral direction”. Further, the distance in the vertical direction from the lower end surface 20 of the cylindrical portion 21 is referred to as “height”.

The outer shell of the sealing device 101 includes a cylindrical portion 21, an inclined wall portion 22 and a ceiling portion 23. The cylindrical portion 21 is provided substantially parallel to the central axis O. The inclined wall portion 22 and the ceiling portion 23 are provided in a dome shape above the cylindrical portion 21. The inclined wall portion 22 connects the upper end of the cylindrical portion 21 and the peripheral edge of the ceiling portion 23, and is inclined inward from the cylindrical portion 21 toward the ceiling portion 23. The inclined wall portion 22 of the present embodiment is formed in a taper shape whose axial sectional shape is a straight line.
On the outer wall of the cylindrical portion 21, a plurality of ribs 26 as “uneven portions” are formed in the vertical direction, that is, along the axial direction of the cylindrical portion 21. For example, in the present embodiment, eight ribs 26 are formed at equal intervals in the circumferential direction. The plurality of ribs 26 extend from the lower end surface 20 of the cylindrical portion 21 to below the boundary between the cylindrical portion 21 and the inclined portion 22.

In the accommodation space 31 formed inside the cylinder portion 21, a plurality of suspension portions 32 that are suspended from the ceiling portion 23 and connect the ceiling portion 23 and the locking claws 33 are provided. For example, in this embodiment, four hanging parts 32 are provided radially.
A locking claw 33 having a substantially triangular cross section in the axial direction is formed at the lower end of the suspension part 32 so as to protrude in the radially inward direction. The locking claw 33 is formed such that the height of the upper surface 34 is substantially constant, and the lower surface 36 rises from the radially outward direction toward the radially inward direction. The upper surface 34 and the lower surface 36 are connected by a radially inner surface 35 having a relatively narrow vertical width.

The ceiling part 23 has a plurality of ceiling holes 25 located immediately above the upper surface 34 of the locking claw 33. A connecting portion 24 is formed between the circumferential directions of the ceiling holes 25. The connection part 24 bridges the center part 231 and the peripheral part 232 of the ceiling part 23.
By providing the ceiling hole 25, the undercut processing on the upper surface 34 side of the locking claw 33 can be handled by nesting from the ceiling portion 23 side in the molding die of the sealing tool 101. Further, as will be described later, the ceiling hole 25 functions so that the sealing tool 101 is easily broken when the sealing tool 101 is grasped by a tool for removing the sealing tool 101 from the sealing screw. That is, since the sealing tool 101 has the ceiling holes 25, stress concentrates on the connection portions 24 between the ceiling holes 25, and the connection portions 24 are broken as breakage starting points.

Next, the usage pattern of the sealing tool 101 is demonstrated with reference to FIGS.
As shown in FIG. 4, the sealing tool 101 is attached to the head of the sealing screw 7 to which the cover 81 and the case 86 are screwed in the wattmeter 8 as a “sealing object”. The left side of FIG. 4 shows a state before the sealing tool 101 is attached to the sealing screw 7, and the right side of FIG. 4 shows a state after the sealing tool 101 is attached to the sealing screw 7.

  A minus-shaped working groove 72 is formed in the head 71 of the sealing screw 7. When the sealing tool 101 is not attached, the sealing screw 7 can be easily turned using a general minus driver. On the other hand, in the state where the sealing tool 101 is attached, the working groove 72 of the sealing screw 7 is shielded, so that the sealing screw 7 cannot be turned, and thus the cover 81 cannot be opened. That is, in order to open the cover 81, it is necessary to remove the sealing tool 101 from the sealing screw 7, insert a screwdriver into the working groove 72 of the sealing screw 7, and turn the sealing screw 7.

Specifically, as shown in FIG. 5, the sealing screw 7 has a head 71, a body 76, a male screw 77, and the like. The head 71 has a work groove 72 formed on the top surface 711 and a locking groove 73 formed on the side surface 712. A chamfer 74 is formed at the lower mouth of the locking groove 73 on the side surface of the head 71.
The trunk portion 76 has a smaller diameter than the head portion 71, and a stepped surface 75 between the head portion 71 and the trunk portion 76 contacts the surface of the cover 81. The male screw portion 77 is screwed into the female screw hole of the case 86.

  The head 71 of the sealing screw 7 can be inserted into the cylindrical portion 21 of the sealing tool 101. When attaching the sealing tool 101 to the sealing screw 7, the head 71 of the sealing screw 7 is inserted into the cylinder portion 21, and the sealing claw 33 is sealed from a position where the lower surface 36 of the locking claw 33 is in contact with the top surface 711 of the head 71. The tool 101 is pressed downward. Then, since the lower surface 36 is inclined, the suspension part 32 bends outward, and the locking claw 33 gets over the upper part of the head 71 and fits into the locking groove 73. At this time, the upper surface 34 and the lower surface 36 of the locking claw 33 abut against the wall of the locking groove 73, and the inner diameter surface 35 of the locking claw 33 faces the groove bottom of the locking groove 73. Thus, the locking claw 33 is locked in the locking groove 73 of the sealing screw 7, so that the sealing tool 101 is attached to the sealing screw 7.

  When the sealing tool 101 is attached to the sealing screw 7, the ceiling portion 23 shields the work groove 72 formed on the top surface 711 of the head 71 of the sealing screw 7. Since the sealing tool 101 is formed of an opaque resin material, it is impossible to visually recognize the internal structure of the locking claw 33 and the like and the presence of the work groove 72 below the ceiling portion 23.

Since the ABS resin, which is the material of the sealing device 101, does not have elasticity like an elastomer resin, for example, it cannot be removed from the state in which the locking claw 33 is locked in the locking groove 73 while maintaining the original shape. Thus, since the sealing tool 101 of this embodiment leaves the trace opened by persons other than a regular worker, when removing from the sealing screw 7, it is requested | required as an essential function.
When a person other than a regular worker attempts to remove the sealing tool 101, it is usually assumed that the sealing tool 101 is gripped using a tool such as pliers. Therefore, an operation of gripping the sealing tool 101 using a tool such as pliers and an operation of the locking claw 33 and the like by the operation will be described with reference to FIGS. 7 and 8, the illustration of the rib 26 is omitted.

As shown in FIG. 6A, when the inclined wall portion 22 is to be gripped with the pliers 9 from above the sealing tool 101, only the tip corner portion of the pliers 9 hits, so that it cannot be slid and gripped.
Here, as a comparative example, as shown in FIG. 7, a substantially cylindrical sealing device 108 having no inclined wall portion is assumed. The configuration other than the inclined wall is the same as the sealing tool 101.
As shown in FIG. 7A, the sealing tool 108 is in contact with the upper part of the cylinder part 21 so that the pliers 9 do not slip, so that only the upper part is compared even if the pliers 9 are not inserted all the way into the outer wall of the cylinder part 21. It is possible to grip with a small force. Then, as shown in FIG. 7B, since there is a sufficient escape space S on the outer diameter side of the suspension part 32, the upper part of the cylinder part 21 is compressed inward in the radial direction as indicated by the block arrow F. When the ceiling part 23 bends, the suspension part 32 suspended from the ceiling part 23 is deformed so as to escape radially outward with the root as a fulcrum (see arrow E). As a result, the locking claw 33 may come off from the locking groove 73 of the sealing screw 7, and the sealing tool 108 may be removed from the sealing screw 7 without being destroyed.

Therefore, in the present embodiment, by providing the inclined wall portion 22 on the upper portion of the cylindrical portion 21, workability is intentionally lowered so that the pliers 9 can slide. Accordingly, as shown in FIGS. 6B and 8A, when the outer wall of the cylinder part 21 is gripped by the pliers 9 from above the sealing tool 101, the pliers 9 must be inserted deep into the outer wall of the cylinder part 21. I must.
As shown in FIG. 8B, since the sealing part 101 is not directly connected to the cylinder part 21 and the ceiling part 23, even if the outer wall of the cylinder part 21 is compressed in the radially inward direction, the sealing tool 108 of the comparative example. Compared to the above, the ceiling 23 is less likely to bend. Even if the ceiling 23 is bent, the space S ′ outside the diameter of the suspension part 32 is narrow, so that the suspension part 32 is restricted from being deformed in the radially outward direction. Therefore, the latching claw 33 cannot be removed from the latching groove 73 by deforming the hanging part 32 without destroying the sealing tool 101. That is, in order to remove the sealing tool 101 from the sealing screw 7, the pliers 9 must be inserted all the way into the outer wall of the cylindrical portion 21 and the sealing tool 101 can be destroyed by applying a relatively large force.

In particular, in the present embodiment, since the direction of the rib 26 is orthogonal to the direction of the inner blade 91 of the pliers 9, it is necessary to apply extra force because the hook between the rib 26 and the inner blade 91 cannot be obtained.
Also, as shown in FIG. 6C, when the outer wall of the cylinder portion 21 is gripped with the pliers 9 from the lateral direction, the sealing tool 101 cannot be removed unless a relatively large force is applied.
Since the sealing tool 101 is broken as shown in FIG. 9 by the gripping force at the time of the detaching operation, the trace of removing the sealing tool 101 is obvious at a glance. In other words, the sealing tool 101 is designed with respect to the positional relationship between the tube portion 21 and the locking claw 33, the thickness of each portion, and the like so as to be broken into a form as shown in FIG.

  As described above, each time the wattmeter is opened, the set of sealing tools 101 corresponding to the number of sealing screws 7 is destroyed. That is, the sealing tool 101 is used as a consumable item. A regular worker has a replacement for the sealing tool 101, opens the power meter 8, and then attaches a new sealing tool 101 to the sealing screw 7. On the other hand, when a person who does not have a replacement destroys the sealing tool 101 and opens the wattmeter 8, the sealing tool 101 remains in a broken state, and an illegal act or a preliminary act thereof is performed. Can leave a trace.

The effect of the sealing tool 101 of this embodiment is demonstrated contrasting with the prior art disclosed by patent document 1. FIG.
(1) The sealing tool of a prior art is demonstrated with reference to FIG. A sealing tool 109 shown in FIG. 12 is provided on the wattmeter cover 81 and used for the same application as the sealing tool 101 of this embodiment.
The sealing tool 109 is composed of three members: a main body portion 4, a cap 5, and a locking spring 6.
The main body 4 is formed in a cylindrical shape with, for example, PMMA (acrylic) resin, and includes an outer cylinder 41, a bottom wall 42, and the like. An insertion hole 43 through which the head 71 of the sealing screw 7 can be inserted is formed at the center of the bottom wall 42. The portion connected from the outer cylinder 41 to the bottom wall 42 has an outer diameter narrowed in a tapered shape to form a thin portion 44.

The cap 5 is formed of PMMA (acrylic) resin or the like, similar to the main body portion 4, and is formed on the top surface 711 of the head portion so as to cover the fitting portion 51 that fits the outer cylinder 41 of the main body portion 4 and the sealing screw 7. The ceiling portion 52 that shields the work groove 72 formed, and the inner cylinder 53 that hangs down from the ceiling portion 52 are included.
The locking spring 6 is formed of a steel plate, and a plurality of claw pieces 62 are formed on the inner side of an annular or C-shaped base portion 61 so as to protrude upwardly.

  After the base 61 of the locking spring 6 is placed on the bottom wall 42 of the main body 4, the cap 5 is fitted into the main body 4, and the gap between the lower end surface 54 of the fitting portion 51 and the bottom wall 42 of the main body 4. The cap 5 and the main body 4 are welded together while sandwiching the base 61 of the sealing screw 7. The portion for sandwiching the base 61 is a space for joining members together.

  When attaching the sealing tool 109 to the sealing screw 7, the head 71 of the sealing screw 7 is inserted into the insertion hole 43, and the plurality of claw pieces 62 of the locking spring 6 abut on the top surface of the head 71 of the sealing screw 7. The sealing tool 109 is pushed down from this state. Then, the plurality of claw pieces 62 are locked in the locking grooves 73 on the head side surface 712 of the sealing screw 7 while being spread outward in the radial direction. Thereby, the sealing tool 109 cannot be removed from the sealing screw 7 while maintaining the original shape. When a force is applied to remove the sealing tool 109 with a tool or the like, the sealing tool 109 is broken starting from the thin portion 44 of the main body 4.

When the sealing tool 101 of this embodiment is attached to the sealing screw 7 as in the case of the sealing tool 109 of the prior art, the locking claw 33 is locked to the locking groove 73 and cannot be removed while maintaining its original shape. . When a force is applied to remove the sealing tool 101 with a tool or the like, the sealing tool 101 is broken starting from the connecting portion 24 of the ceiling portion 23 or the like.
Therefore, when the sealing tool 101 is destroyed by a person other than a regular worker, it is assumed that an illegal act of opening the power meter, or a possibility that a preliminary act has been performed. In addition, it is possible to provide a deterrent effect that destroys the motives of fraud before it is widely known by destroying the sealing tool 101.

(2) Since the sealing tool 101 of this embodiment has the inclined wall part 22 formed on the upper part of the cylindrical part 21, the sealing tool 101 is gripped with a tool such as pliers 9 to remove the sealing tool 101 from the head 71 of the sealing screw 7. When trying, the tool slips and is difficult to grasp.
Unlike the sealing device 108 of the comparative example, when the upper wall of the tube portion 21 can be gripped with a relatively small force without using the inclined wall portion 22, the ceiling portion 23 bends and the ceiling portion 23 The suspension part 32 that connects the locking claw 33 and the locking claw 33 is deformed so as to escape radially outward with the root as a fulcrum, so that the locking claw 33 comes off the locking groove 73 of the sealing screw 7 and the sealing tool 108 is There is a risk of being removed from the sealing screw 7 without being destroyed.
On the other hand, since the sealing tool 101 of this embodiment becomes difficult to hold | grip the upper part of the cylinder part 21 with tools, such as pliers 9, by providing the inclined wall part 22, the suspension part 32 is deformed by bending the ceiling part 23. Thus, the locking claw 33 cannot be removed from the locking groove 73. Therefore, it is necessary to insert the pliers 9 to the back of the outer wall of the cylindrical portion 21 and apply a relatively large force to grip the outer wall of the cylindrical portion 21. As a result, the sealing tool 101 can be destroyed reliably.

  (3) Since the sealing tool 101 of the present embodiment is formed of a single resin part as compared with the sealing tool 109 of the prior art, the number of parts can be reduced. Moreover, since the space for joining members becomes unnecessary, a physique can be made small. Furthermore, since the ABS resin, which is the material of the sealing tool 101, is less likely to be crushed at the time of destruction than the PMMA resin exemplified in the prior art, the scattering of resin pieces can be reduced.

  (4) Since the sealing tool 101 of the present embodiment is formed of an opaque resin, the internal structure cannot be visually recognized. In general, since it is difficult for a person to be interested in what cannot recognize the internal structure, it is possible to prevent the incentives of fraud.

(5) In the sealing device 101 of the present embodiment, longitudinal ribs 26 are formed on the outer wall of the cylindrical portion 21. Thereby, when a regular worker works, it becomes easy to hold the cylinder part 21 by hand.
Further, when the outer wall of the cylindrical portion 21 is gripped from above the sealing tool 101 with the pliers 9, the rib 26 is perpendicular to the direction of the inner blade 91 of the pliers 9, so that the rib 26 and the inner blade 91 are caught. It is necessary to apply extra power as much as possible. Therefore, the sealing tool 101 can be destroyed more reliably.
Furthermore, compared to a configuration in which ribs are provided in the lateral direction, there is no step in the circumferential direction on the PL surface of the molding die, so that the mold structure is simplified and molding burrs are less likely to occur.

(Second and third embodiments)
Next, sealing tools according to second and third embodiments of the present invention will be described with reference to FIGS. 10 and 11. In the following description, substantially the same components as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted.
The second and third embodiments are the same as the first embodiment except for the configuration related to the ribs. That is, it is integrally formed of an opaque resin material such as ABS, and has a configuration such as the inclined wall portion 22 and the locking claw 33. Therefore, the effects (1) to (4) of the first embodiment are similarly obtained.

In the sealing device 102 according to the second embodiment shown in FIG. 10A, lateral ribs 27 are formed on the outer wall of the cylindrical portion 21 as “uneven portions”.
When gripping the outer wall of the cylinder portion 21 with the pliers 9 from above the sealing tool 102 as shown in FIG. 11A, the direction of the ribs 27 is the same as the direction of the inner blade 91 of the pliers 9, The inner blade 91 is caught and workability is good. Still, in order to remove the sealing tool 102, it is necessary to insert the pliers 9 to the back of the outer wall of the cylinder part 21 and apply a relatively large force to grip the outer wall of the cylinder part 21. As a result, the sealing tool 102 is reliably destroyed.
As shown in FIG. 11 (b), when the outer wall of the cylinder part 21 is gripped by the pliers 9 from the lateral direction of the sealing tool 102, the pliers 9 are moved to the back of the outer wall of the cylinder part 21 in order to remove the sealing tool 102. It is necessary to insert and apply a relatively large force to grip the outer wall of the cylindrical portion 21. As a result, the sealing tool 102 is reliably destroyed.

  Moreover, the sealing tool 103 of 3rd Embodiment shown in FIG.10 (b) does not have uneven | corrugated | grooved parts, such as a rib, in the outer wall of the cylinder part 21. FIG. As described above, uneven portions such as ribs may not be formed on the outer wall of the cylindrical portion 21. Also in this case, in order to remove the sealing tool 103, it is necessary to insert the pliers 9 to the back of the outer wall of the cylinder part 21 and apply a relatively large force to grip the outer wall of the cylinder part 21. As a result, the sealing tool 103 is reliably destroyed.

(Other embodiments)
(A) The material of the sealing tool is not limited to the ABS resin, and any material may be used as long as it has a property that can be reliably destroyed when an attempt is made to remove it using a general tool. For example, AES resin, PC alloy, PA (polyamide), POM (polyacetal) or the like can be employed.
(A) The inclined wall portion 22 of the above-described embodiment is formed in a tapered shape having a straight cross-sectional shape in the axial direction. In other embodiments, the inclined wall portion may be formed in a convex curved surface shape in which the axial cross-sectional shape is expressed by a convex curve upward.

(C) The number of the plurality of hanging portions, the locking claws, and the plurality of ribs is not limited to the number of the above-described embodiments. Further, they may be formed at unequal intervals in the circumferential direction.
(D) The uneven portion formed on the outer wall of the cylindrical portion 21 is not limited to a rib extending in the vertical direction or the horizontal direction, and may be a protrusion or a depression provided in a stepping stone shape.

(E) The sealing tool of the present invention is not limited to a power meter, and can be applied to sealing objects for various purposes in order to prevent illegal acts and mischief by non-regular users.
As mentioned above, this invention is not limited to such embodiment, In the range which does not deviate from the meaning of invention, it can implement with a various form.

101, 102, 103 ... Sealing tool,
21 ... Cylinder part,
22 ... inclined wall part,
23 ... ceiling part,
26, 27 ... ribs (uneven portions),
33 ... locking claw,
7 ・ ・ ・ Seal screw,
71 ... head,
72 ... working groove,
73 ... locking groove,
8: Wattmeter (sealed object).

Claims (4)

The sealing screw (7) screwed to the sealing object (8) can be attached to the head (71) of the sealing screw so that the sealing screw (7) cannot be operated from the outside, and is destroyed when the sealing screw is removed from the sealing screw. Sealing device (101, 102, 103),
Integrally formed,
A cylindrical portion (21) into which the head of the sealing screw can be inserted;
A locking claw (33) that is provided on the inner side of the cylindrical portion and that locks in a locking groove (73) formed on a side surface of the head of the sealing screw when the sealing tool is attached to the sealing screw;
A ceiling portion (23) that is provided on one of the axial directions of the cylindrical portion and shields the working groove (72) formed on the top surface of the sealing screw when the sealing tool is attached to the sealing screw;
An inclined wall portion (22) that connects one end of the cylindrical portion and the peripheral edge of the ceiling portion, and is inclined inward from the cylindrical portion toward the ceiling portion,
A sealing device comprising:   The sealing tool (101, 102) according to claim 1, wherein uneven portions (26, 27) are formed on an outer wall of the cylindrical portion.   The sealing tool (101) according to claim 2, wherein the uneven portion is a plurality of ribs (26) formed in the circumferential direction along the axial direction of the cylindrical portion.   The sealing tool according to any one of claims 1 to 3, wherein the sealing tool is made of an opaque resin material.

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