JP3164765B2 - Uninterruptible tool - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an uninterruptible power tool used for replacing a watt-hour meter or the like without interrupting a load, and more particularly, to a power supply side cable and a push-off screw connected to a load side cable. Related to uninterruptible power tools.

[0002]

2. Description of the Related Art FIGS. 3 to 5 show a conventional uninterruptible power tool. First, in FIGS. 3 and 4, reference numeral 21 denotes a main body, and reference numeral 22 denotes a holding table, both of which can be tightened by thumb screws 23 and 24 and a center screw 25. As shown in FIG.
When the main body 21 and the presser base 22 are tightened, grooves 41 to 46 are formed between the main body 21 and the presser base 22 so that the power supply side cable and the load side cable connected to the watt hour meter can be inserted.

[0003] Immediately above these grooves 41 to 46, push-off screws 27 to 29 for pushing off the insulation coating of the power supply side cable and connecting to the electric wires in the cable, and pushing out the insulation coating of the load side cable to remove the cable. Push-off screws 31 to 33 for connecting to the inner electric wires are arranged.

In FIG. 3, reference numeral 26 denotes a bypass switch, and all the push-off screws 27 to 29, 31
By turning on .33 while connected to the power supply side cable and the load side cable, the power supply side cable and the load side cable are connected, bypassing the watt hour meter to be replaced. In FIG. 4, reference numeral 34 denotes a push-off screw 27-2.
The conductor 34 is a bypass conductor as a female screw portion for 9, 31 to 33, and the conductor 34 is electrically connected to the bypass switch 26.

[0005] Fig. 5 shows a state in which the insulation coating of the cable is pushed off by a pushing-off screw and connected to the internal electric wire, 51 is a watt-hour meter to be replaced, and 52 is a power supply side or load side cable.

FIG. 6 shows the structure of the push-off screw. Here, the reference numeral “27” is used as the push-off screw, but other push-off screws 28, 29, 31 to 33 are used.
Has the same structure.

In the figure, the push-off screw 27 is
7A, a male screw portion 27B, and an annular blade portion 27C. The annular blade portion 27C is formed by cutting the lower end portion of a round bar material into a circular hole and forming a thin annular shape. By screwing the male screw portion 27B into the bypass conductor 34, the annular blade portion 27C is formed. Cable 5 descends while rotating
2 is cut off and electrically connected to an electric wire.

[0008]

In the conventional uninterruptible power tool, the distal end face of the annular blade portion of the push-off screw pushes off the insulation coating of the cable, and the electrical connection between the push-off screw and the electric wire is made in a state where the tip end face is pressed against the electric wire. Connection is maintained. In this case, it is necessary to use a large tightening force to push off the insulation coating (made of elastic vinyl etc.) on the surface of the cable, so the bypass conductor as the male thread of the push-off screw and the female thread to be screwed to it There is a disadvantage that the wear of the tool is severe and the life of the uninterruptible tool is shortened.

Further, since the connection between the push-off screw and the electric wire is also in a surface contact state, the connection between the push-off screw and the electric wire is loosened due to vibration at the time of replacing the watt-hour meter and external force applied to each cable. There were also problems such as failure. If the tightening force of the push-off screw is further increased in order to prevent the connection failure, there is a disadvantage that the wear of the push-off screw and the like is further increased.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an uninterruptible tool capable of preventing abrasion of a push-off screw or the like, extending a product life, and obtaining a reliable connection state with an electric wire.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a wireless communication system which is used to replace an instrument without interruption by short-circuiting a power supply side cable and a load side cable connected to the instrument. A power failure tool, comprising: an uninterruptible tool including a push-off screw connected to an electric wire in each cable by pushing off an insulating coating of each cable, wherein an annular blade portion formed at a tip of the push-off screw has an annular shape. On the end face , an annular concavo-convex tip which is irregular in the axial direction is formed.

[0012] With this uneven tip, the insulating coating of the cable can be pushed off with a small force when the push-off screw is tightened. Further, when the concave / convex distal end portion enters the cable, the wire is securely engaged with the concave portion of the concave / convex distal end portion, so that a reliable mechanical and electrical connection state can be obtained.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. First, FIG. 1 shows a push-off screw used in this embodiment, wherein (A) is a front view of a tooth, and (B) is a bottom view of an annular blade portion. The push-off screw 10 includes a head 11, a male screw 12, and an annular blade 13, and a lower end of the annular blade 13 is formed with an uneven tip 14.

The annular blade portion 13 is formed by cutting the lower end of a round bar material into a circular hole as in the prior art to form a thin annular shape. It is formed by processing the lower end into an uneven shape along the axial direction. Note that the entire push-off screw 10 is formed of a conductive material.

Here, the entire structure of the uninterruptible tool according to the present embodiment is the same as that of the prior art shown in FIGS. 3 to 5, and therefore, description thereof will be omitted to avoid duplication.

FIG. 2 is a sectional view showing the use state of the push-off screw 10. As shown in FIG. In the figure, a cable 52 that is a power supply side cable or a load side cable is inserted into a groove 41 between the main body 21 and the holding table 22. Here, 52A
Indicates an insulating coating of the cable 52, and 52B indicates an internal electric wire.

When the cable 52 is disposed immediately below the push-off screw 10 and the push-off screw 10 is tightened, the concave / convex distal end portion 14 rotates downward and pushes off the insulating coating 52A to come into contact with the electric wire 52B. At this time, in the related art, a large tightening force is required because the distal end surface of the annular blade portion of the push-off screw comes into surface contact to push off the insulating coating, but in the present embodiment, the substantially saw-tooth-shaped uneven distal end portion 14 rotates. Since it proceeds while moving, the insulating coating 52A can be cut with a slight force. Therefore, the degree of wear of the male screw part 12 and the bypass conductor 34 as the female screw part screwed with the male screw part 12 is reduced.

Further, in a state where the concave and convex front end portion 14 is pressed against the electric wire 52B, the electric wire 52B engages with the concave portion of the concave and convex front end portion 14, so that the concave and convex front end portion 14 and the electric wire 52B are securely connected mechanically. . At the same time, the contact area between the two increases, so that a good electrical connection can be obtained. Therefore, even if various external forces such as vibration when the watt hour meter is replaced are applied, there is no possibility that a connection failure will occur.

The power supply side cable,
By turning on the bypass switch 26 shown in FIG. 4 after connecting the push-off screws for all the load side cables, the power supply side cable and the load side cable are short-circuited by bypassing the watt hour meter. The watt hour meter may be replaced with a new one in the state. Further, in the above embodiment, the uneven shape of the uneven tip portion 14 can have various shapes such as a rectangular shape, a trapezoidal shape, and a triangular shape when viewed from the side.

[0020]

As described above, according to the present invention, by forming the concave and convex tip portions on the annular blade portion of the push-off screw, the insulating coating of the cable can be pushed off with a small force when the push-off screw is tightened. it can. Accordingly, wear of the push-screw and the bypass conductor can be prevented, and the life of these components and the entire product can be extended.

Further, when the push screw is pressed against the electric wire, the tip of the concave and convex portion and the electric wire are securely and firmly engaged with each other, and the mechanical and electrical connection between the two is perfect. The connected state can be maintained.

[Brief description of the drawings]

FIG. 1 is an explanatory view of a push-off screw according to an embodiment of the present invention.

FIG. 2 is a sectional view showing a use state of a push-off screw.

FIG. 3 is a plan view of the prior art.

FIG. 4 is a sectional view taken along line AA of FIG. 3;

FIG. 5 is a side view showing a use state of the related art.

FIG. 6 is a front view of a push-screw according to the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Push-off screw 11 Head 12 Male screw part 13 Annular blade part 14 Irregular tip part 21 Main body 22 Holder 26 Bypass switch 34 Bypass conductor (female screw part) 41 Groove 52 Cable 52A Insulation coating 52B Electric wire

Claims (1)

(57) [Claims] An uninterruptible tool used for exchanging an instrument without interruption by short-circuiting a power supply side cable and a load side cable connected to the instrument, wherein the insulation covering of each of the cables is pushed out. An uninterruptible tool provided with a push-off screw connected to an electric wire in each cable, wherein an annular blade portion formed at a tip of the push-off screw is annular.
An uninterruptible power tool characterized in that an annular concavo-convex tip portion that protrudes and contracts in the axial direction is formed on an end surface of the power tool.