JP2012202500A - Washer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an act of gripping a washer itself or damaging the washer with a tool such as pliers or pinchers.SOLUTION: The washer includes a pedestal part of disk shape, and a surrounding part rising from the outer peripheral edge of the pedestal part. The center of the pedestal part is provided with an opening through which a shank of a screw can be inserted, and the pedestal part and the surrounding part form a recess that can store a head of the screw when the shank of the screw is inserted through the opening. The outer peripheral surface of the surrounding part is formed as a plane inclining to approach as it goes away from the pedestal part.

Description

  The present invention relates to a washer that is sandwiched between a screw head for fixing a member to another member and a member to be fastened, and more particularly to a washer that prevents loosening of a screw due to mischief or the like.

  For example, a watt hour meter indicating the amount of electricity used is installed in buildings such as residential buildings, shops, factories, etc., to which electricity, gas, water, etc. are supplied. An external power input line and a power supply line to the building are connected to the watt hour meter, and the value of the watt hour meter increases according to the amount of power used in the building. The watt hour meter is periodically metered by a worker of a supplier such as electricity, and based on the meter reading, a charge corresponding to the amount of power used in the building is calculated.

  On the other hand, it may be necessary to stop supplying power to the building for various reasons. At that time, the power supply line to the building is disconnected from the terminal of the watt-hour meter. However, if anyone can easily reconnect the removed indoor power supply line to the watt hour meter, the purpose of stopping the supply cannot be achieved. Further, it is dangerous if a person can easily touch a terminal to which an external power input line to the watt hour meter and a power supply line to the building are connected. For this reason, a terminal cover is attached to the connection terminal between the external power input line and the power supply line to the building. In addition, a screw is used to prevent the terminal cover from being easily removed. The terminal cover is fixed.

  However, if the terminal cover is fixed using a commercially available tool, for example, a screw that can be turned with a plus or minus screwdriver, the terminal cover is easily removed together with the screw due to mischief, etc. Cannot be achieved or safety is hindered. Therefore, in order to fix the terminal cover, a screw that can be tightened or loosened with a special tool not commercially available is used.

JP, 2003-278727, A Patent document 1 shows a washer provided with a tool control part for controlling insertion of a detachable tool between screw heads. According to Patent Document 1, the screw can be loosened by using a dedicated attaching / detaching tool, but the space between the screw head and the armor restricting portion of the washer is narrow, so the screw head is gripped and turned with pliers or pliers. It is not possible.

  However, there is a strong demand for preventing the act of grasping the washer itself with tools such as pliers and pliers and turning the screw together with the washer to loosen the screw or damage the washer.

  Therefore, the present invention has an object to provide a washer that can prevent an act of grasping the washer itself with a tool such as a pliers or a pliers and turning the screw together with the washer to loosen the screw or damage the washer. To do.

  Therefore, the washer according to the present invention comprises a disk-shaped pedestal portion and a surrounding portion rising from the outer peripheral edge of the pedestal portion, and has an opening through which the screw shaft can be inserted at the center of the pedestal portion, When the screw shaft is inserted through the opening, the base portion and the surrounding portion form a recess that can accommodate the head of the screw, and the outer peripheral surface of the surrounding portion moves away from the base portion. Therefore, it is a flat surface inclined so as to approach.

  In the washer, the depth of the recess may be greater than the length of the head of the screw.

  In the washer, the width of the recess may be slightly larger than the area of the seat surface of the screw head.

  The washer may be formed of an iron-carbon-copper-nickel material.

  In the washer, the inclination angle of the outer peripheral surface of the surrounding portion may be about 60 degrees from the lower surface of the pedestal portion.

  Further, the fixture according to the present invention includes a washer, a shaft that can be inserted into the opening of the pedestal portion of the washer, and a head that is attached to an end portion of the shaft and can be received in the recess of the washer. And a screw having a portion.

  The watt-hour meter according to the present invention is provided with a watt-hour meter display unit that measures and displays the usage amount of power, etc., and a terminal to which an external power input line and a power supply line to a building are connected. A terminal cover that covers the terminal portion, and the fixture described above, and the female screw hole of the terminal portion, the hole of the terminal cover, and the hole of the washer of the fixture are aligned. The screw shaft of the fixture is inserted into the female screw hole of the terminal portion from the opening of the washer through the opening of the terminal cover, and the terminal cover is rotated by turning the head of the screw. It is fixed to the terminal portion, and the head of the screw is housed in the recess of the washer.

  In addition, the fixing method according to the present invention includes a watt hour meter display unit that measures and displays the amount of power used, and a terminal to which an external power input line and a power supply line to a building are connected. A fixing method for fixing the terminal cover of a watt-hour meter comprising the provided terminal part, a terminal cover covering the terminal part, and the above-described fixture, the female screw hole of the terminal part, The opening of the terminal cover and the opening of the washer of the fixture are aligned, and the screw shaft of the fixture passes through the opening of the terminal cover from the opening of the washer to the female screw of the terminal portion. The terminal cover of the watt-hour meter, wherein the screw head is housed in the recess of the washer when the screw cover is fixed by tightening the screw head by turning and tightening the screw head. Is fixed to the terminal portion.

  According to the present invention, it is possible to provide a washer that prevents the washer itself from being gripped and rotated or damaged.

FIG. 1 is a perspective view showing a washer according to an embodiment of the present invention. FIG. 2 is a plan view of the washer shown in FIG. FIG. 3 is a cross-sectional view of the washer as viewed in the direction of the arrow from the line 3A-3A in FIG. FIG. 4 is a partial cross-sectional view showing a state in which screws are inserted into the washer shown in FIG. 3 to fix the members together. FIG. 5 is a plan view of the head of the screw shown in FIG. FIG. 6A is a front view showing a simplified configuration of the watt-hour meter. 6B is a side view of the watt-hour meter shown in FIG. 6A.

  Hereinafter, a washer according to the present invention will be described with reference to the accompanying drawings. In all drawings, the thickness, length, shape, spacing between members, gaps, etc. of each member are appropriately expanded, reduced, deformed, simplified, etc. for easy understanding. The present invention is not limited to the shape of the drawings. In the description of the drawing, the vertical and horizontal expressions represent the direction along the plane of the drawing in a state where the drawing is placed in the vertical plane for convenience of description. In the different drawings, the same members are denoted by the same reference numerals, and the description thereof will be omitted depending on the case.

[Structure of washer]
FIG. 1 is a perspective view of a washer 10 according to an embodiment of the present invention, FIG. 2 is a plan view of the washer 10, and FIG. 3 is a cross-sectional view of the washer 10 taken along line 3A-3A in FIG. is there.

  The washer 10 is made of, for example, an iron-carbon-copper-nickel material, and has a high hardness whose surface is carburized and quenched, and includes a substantially disk-shaped pedestal portion 11 and a surrounding portion 12 rising from the periphery thereof. Is provided.

  The pedestal portion 11 is formed integrally with the surrounding portion 12, and has an upper surface 11a and a lower surface 11b. The surrounding portion 12 includes an outer peripheral surface 12a that is inclined so as to approach the upper side, an inner peripheral surface 12b that forms a recess 13 such that the upper surface 11a of the pedestal portion 11 serves as a bottom surface, and an inner peripheral surface 12b and an outer peripheral surface 12a. And a top surface 12c to be connected. A narrow flat surface portion 21 d is formed at a position where the outer peripheral edge of the lower surface 11 b of the pedestal portion 11 is in contact with the lower edge of the outer peripheral surface 12 a of the surrounding portion 12.

  Further, an opening 14 is formed at the center of the pedestal 11, and the shaft 45 of the screw 40 shown in FIG. 4 is inserted into the opening 14.

  The outline of the dimension of each part of the washer 10 is as follows. The diameter of the circular lower surface 11b of the base 11 (the diameter of the washer 10) is about 18 mm, the diameter of the upper surface 11a is about 11 mm, and the distance between the upper surface 11a and the lower surface 11b (the thickness of the base 11) is about 1 mm. The diameter of the opening 14 is about 4 mm. The diameter of the circular top surface 12c formed by the upper edge of the inclined outer peripheral surface 12a of the surrounding portion 12 is about 14 mm, the diameter of the concave portion 13 is about 11 mm, and the depth of the concave portion 13 is about 3 mm. The angle from the lower surface 11b of the base part 11 to the outer peripheral surface 12a is about 60 degrees. The distance from the lower surface 11b of the pedestal portion 11 to the top surface 12c of the surrounding portion 12 (height of the washer 10) is about 4 mm.

  The inclined outer peripheral surface 12a of the surrounding portion 12 is a flat slope. This inclination angle is about 60 degrees as described above, but this is an example. When the washer 10 is mounted between the head of the screw and the member to be fastened, the washer 10 is made of pliers, pliers or the like. Any other inclination angle may be used as long as it is difficult to grasp with a tool or to pry a flathead screwdriver from the edge of the washer 10. The outer peripheral surface 12a is preferably a flat surface, but may be somewhat curved as long as it cannot be gripped by a tool such as pliers or pliers.

  Further, for example, when the washer 10 is used to fix the terminal cover of the watt hour meter, the washer 10 needs to have a diameter that does not protrude from the edge of the terminal cover of the watt hour meter.

  Furthermore, the depth of the recess 13 is desirably larger than the height of the screw head, but if it is difficult to pry a flathead screwdriver through the gap between the washer 10 and the screw head, It may be smaller than the height of the part.

[Usage of washers]
4 is a partial cross-sectional view showing a state in which the screw 40 is inserted into the washer 10 shown in FIG. 3, and FIG. 5 is a plan view of the screw 40 shown in FIG. FIG. 6A is a front view showing a simplified configuration of the watt hour meter 60, and FIG. 6B is a side view of the watt hour meter 60.

  As shown in FIGS. 4 and 5, the screw 40 includes a head 41 and a shaft 45. The shaft 45 has a thread portion 45s in which a screw thread and a thread groove are formed. The head 41 of the screw 40 has a substantially truss shape, and the upper surface 42 is flat. A triangular groove 42b with rounded corners is formed on the upper surface 42, and a protrusion 42a is formed at the center. The tool for turning such a screw has a triangular protrusion with rounded corners that fits in the triangular groove 42b, and a recess into which the protrusion 42a is inserted is formed at the center. (Not shown).

  As shown in FIGS. 6A and 6B, the watt hour meter 60 includes a watt hour meter display unit 62 and a terminal unit 56. The watt-hour meter display unit 62 is surrounded by a transparent case such as glass, and has a window for measuring in accordance with the use of power in the building and displaying the measured value. Although not shown, the terminal unit 56 is provided with a terminal to which an external power input line and a power supply line to the building are connected. A terminal cover 52 is fixed to the front surface of the terminal cover 52 with a screw 40 through a washer 10.

  Based on FIG. 4, the case where the terminal cover 52 is fixed to the terminal block 56 of a watt-hour meter is demonstrated. A space 54 between the terminal block 56 and the terminal cover 52 accommodates a terminal to which an external power input line (not shown) is connected and a terminal to which a power supply line to the building is connected. .

  First, the terminal cover 52 is put on the terminal block 56 to align the female screw hole 56 s of the terminal block 56 and the hole 52 h of the terminal cover 52, and the opening 14 of the washer 10 is aligned with the hole 52 h of the terminal cover 52. As described above, the washer 10 is placed on the terminal cover 52. Next, the screw 40 is inserted from the screw tip through the opening 14 of the washer 10 to the female screw hole 56 s of the terminal block 56. Next, using a special tool, the screw 40 is turned and tightened to fix the terminal cover 52 to the terminal block 56. This state is shown in FIGS. 4, 6A and 6B.

  In the case of mischief, first, the screw 40 shown in FIGS. 6A and 6B is turned to try to remove it, but there is no dedicated tool for engaging with the specially shaped groove 42a on the upper surface 42 of the screw 40, so the head of the screw 40 It is predicted that the part is tried to be turned with a tool such as pliers or pliers.

  However, in this case, as shown in FIG. 4, the head 41 of the screw 40 has entered the recess 13 of the washer 10 and has not come out of the top surface 12 c of the enclosure 12. The head 41 cannot be grasped with a tool.

  Next, it is predicted that a screwdriver will be inserted between the head 41 of the screw 40 and the washer 10 to lift the screw 40 from the washer 10.

  In this case, since the gap between the outer peripheral edge of the head 41 of the screw 40 and the inner surface 12b of the surrounding portion 12 of the washer 10 is small, the tip of the minus driver cannot be inserted between the head 41 of the screw 40.

  Next, the washer 10 itself is grasped with a tool such as pliers or pliers, and the washer itself is rotated, or a minus driver is inserted between the lower surface 11b of the base 11 of the washer 10 and the terminal cover 52, It is predicted that the washer 10 or the terminal cover 52 is deformed so that the head 41 of the screw 40 is exposed from the concave portion 13 of the surrounding portion 12 of the washer 10.

  In this case, it is difficult to grip the inclined outer peripheral surface 12a of the surrounding portion 12 with a tool such as pliers or pliers. Further, since the lower surface 11b of the pedestal 11 of the washer 10 is in close contact with the terminal cover 52, it is difficult to insert the tip of a minus driver between them. Further, the tip of the minus driver slides on the inclined outer peripheral surface 12a of the surrounding portion 12.

  As described above, when the washer according to the present invention is used, it is difficult to grip the washer itself with a tool such as pliers or pliers or hook the tip of a minus driver with the inclined outer peripheral surface 12a of the surrounding portion 12. Therefore, the effect of preventing mischief is high.

  In the above embodiment, the washer has a disk shape, but may have a triangular shape, a quadrangular shape, or another polygonal shape.

  Although the embodiments of the washer according to the present invention have been described above, the present invention is not limited to these embodiments, and additions, deletions, modifications, etc. that can be easily made by those skilled in the art are included in the present invention. It is to be understood that the technical scope of the present invention is defined by the appended claims.

DESCRIPTION OF SYMBOLS 10 ... Washer 11 ... Base part 11a ... Upper surface 11b ... Lower surface 12 ... Enclosure 12a ... Outer peripheral surface 12b ... Inner peripheral surface 12c ... Top surface 13 ... Recess 14 ... Opening 40 ... Screw 41 ... Screw head 42 ... Upper surface 42a ... Projection 42b ... Groove 45 ... Shaft

Claims (8)

A disk-shaped pedestal,
An enclosure that rises from the outer periphery of the pedestal,
Having a hole through which the screw shaft can be inserted in the center of the pedestal,
When the screw shaft is inserted through the opening, the base portion and the surrounding portion form a recess that can accommodate the screw head,
A washer that is a flat surface that is inclined so that an outer peripheral surface of the surrounding portion approaches as the distance from the pedestal portion increases.   The washer according to claim 1, wherein the depth of the recess is greater than the length of the head of the screw.   The washer according to claim 1 or 2, wherein the width of the recess is slightly larger than the area of the seating surface of the head of the screw.   The washer according to any one of claims 1 to 3, wherein the washer is formed of an iron-carbon-copper-nickel material.   The washer according to any one of claims 1 to 4, wherein an inclination angle of an outer peripheral surface of the surrounding portion is about 60 degrees from a lower surface of the pedestal portion. A washer according to any one of claims 1 to 5;
A fixture having a shaft that can be inserted into the opening of the pedestal portion of the washer, and a screw having a head that is attached to an end portion of the shaft and can be received in a recess of the washer. A watt-hour meter display that measures and displays the amount of power used, etc .;
A terminal portion provided with a terminal to which an external power input line and a power supply line to the building are connected;
A terminal cover covering the terminal part;
A fixture according to claim 6,
The female screw hole of the terminal portion, the opening of the terminal cover, and the opening of the washer of the fixture are aligned, and the screw shaft of the fixture is opened from the opening of the washer. The screw is inserted into the female screw hole of the terminal portion through the hole, the head portion of the screw is turned to fix the terminal cover to the terminal portion, and the head portion of the screw is accommodated in the recess of the washer. , Electricity meter. A watt hour meter display that measures and displays the amount of power used,
A terminal portion provided with a terminal to which an external power input line and a power supply line to the building are connected;
A terminal cover covering the terminal part;
A fixing method for fixing the terminal cover of the watt-hour meter comprising the fixture of claim 6 to the terminal portion,
Align the female screw hole of the terminal portion, the opening of the terminal cover, and the opening of the washer of the fixture,
The shaft of the screw of the fixture is inserted from the opening of the washer through the opening of the terminal cover and into the female screw hole of the terminal portion,
When the screw head is turned and tightened to fix the terminal cover to the terminal part, the screw head is housed in the recess of the washer, and the terminal cover of the watt-hour meter is attached to the terminal part. Fixing method to fix.

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