JPS6151392B2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a grounding plug for wiring ducts, which is a plug that is attached to any location of a wiring duct and has a plug blade in contact with a conductor on the inner surface of the wiring duct, and is equipped with a ground terminal. be.

As shown in Fig. 1, the wiring duct 1 has a metal core 3 covered with a synthetic resin insulation coating 4, and conductors 2 held by the insulation coating 4 on opposing inner surfaces. 1 to electrical equipment, an insulating base 11 is inserted into the wiring duct 1 and is locked at the opening edge of the wiring duct 1, and an insulating base 11 is provided protruding from the outer surface of the insulating base 11. This is accomplished by a plug 10 having a plug blade 12 which is connected to the conductor 2. And this plug 1
0 and the wiring duct 1, an exposed portion 5 of the core 3 with the insulating coating 4 removed is formed on the inner surface of the wiring duct 1, and the plug 10 is provided with an insulating layer. A grounding rod 13 was projected from the center of the upper end of the base 11, and grounding was achieved by bringing the grounding rod 13 into contact with the exposed portion 5 of the core 3. Here, the contact pressure between the earth rod 13 and the exposed portion 5 of the core 3 is obtained by imparting upwardly projecting spring elasticity to the earth rod 13. The structure was as shown in the figure. In other words, a pair of plug blade storage spaces 1 are provided on an insulating base 11 that is divided into two parts.
5, 15 and a grounding rod storage space 16 located between them, and a grounding terminal storage space 1 below the grounding rod storage space 16.
7, and each blade storage space 15, 15
The plug blades 12, 12 are placed in the ground rod storage space 16.
A linear grounding rod 13 is stored in the grounding terminal storage space 17, and a grounding terminal 14 having spring properties is stored in the space 17, and the lower end of the grounding rod 13 comes into contact with the top surface of one end. I was trying to get it. By the way, the dimension l from the inner surface of the opening, which is the locking surface of the plug 10 in the wiring duct 1, to the exposed part 5 of the core 3, and the combined dimension H of the ground rod 13 and the ground terminal 14 shown in FIG. With the above structure, the contact state between the lower end of the earth rod 13 and the earth terminal 14 when the upper end of the earth rod 13 is in contact with the exposed part 5 is as shown by the imaginary line in FIG. The ground terminal 14 has a spring characteristic that takes into account the above-mentioned variations, making it difficult to obtain stable contact.
In order to make the ground terminal 14 stand upright, dimension C in the figure must be made large, but this is due to the difference between the blade holder spring 18 provided on each plug blade 12 and the blade holder spring 19 provided on the ground terminal 14. Standard dimension M between
Since the plug 10 is considerably larger than the plug 10, this causes the plug 10 to become larger as a whole.

The present invention has been made in view of these points, and its purpose is to provide a grounding rod with spring properties that protrude upward, while also making it possible to obtain stable contact between the grounding rod and the grounding terminal. To provide grounded plugs for wiring ducts.

The present invention will be described in detail below based on the illustrated embodiment. As shown in FIG.
15, an earth rod storage space 16 located between the two plug blade storage spaces 15, 15, and an earth terminal storage space 17 located below the earth rod storage space 16. Here, the earth rod storage space 15 is wide except for the guide grooves 20, 20 at the upper and lower ends thereof. and blade holder spring 18
Each of the blades 12, each of which is attached to its lower end, has the same shape as the conventional one, and is stored in each blade storage space 15 so that its upper part can exhibit elasticity in the radial direction.
The ground rod 13 has its upper and lower ends linear and coaxial, and by bending the center part left and right, it can expand and contract up and down while keeping the upper and lower ends coaxial and in a straight line. The earth rod is stored in the earth rod storage space 16 in such a manner that it exhibits a spring property. The ground terminal 14 with the blade receiving spring 19 attached to one end is stored in the ground terminal storage space 17 so that the lower end of the ground rod 13 contacts the upper surface of the other end. Reference numeral 6 in the figure is a body that houses the blade receiving springs 18, 18, 19, and is fixed to the lower end of the insulating base 11 with screws 7.

However, in the case of a lever, the ground rod 13 itself has a spring property and is prevented from sagging to the left or right by the guide grooves 20, 20.
3 itself has the same number of bends and the same shape on the left and right sides, so when the upper end comes into contact with the exposed part 5 of the core 3 and receives pressure, the earth rod 13 alone will not move left or right. As shown in FIG. 7, the lower end of the earth rod 13 always contacts the upper surface of the earth terminal 14 in a substantially constant state regardless of the amount of compression of the earth rod 13, that is, regardless of the contact pressure.

As described above, in the present invention, the grounding rod whose lower end contacts the upper surface of the grounding terminal has spring elasticity in the vertical axial direction, and the lower end of the grounding rod can freely slide on the insulating base only in the vertical direction. Since it is supported, the contact between the ground rod and the ground terminal is stable and the electrical characteristics are good, and the ground terminal can be shortened and miniaturized.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing an example of a grounded plug for wiring ducts, Figure 2 is an exploded perspective view of a conventional example, and Figure 3
The figure is a broken side view of the same as above, FIG. 4 is an explanatory diagram of the same as above, FIG. 5 is an exploded perspective view of one embodiment of the present invention,
7 and 7 are cutaway side views of the same as above, in which 1 is a wiring duct, 2 is a conductor, 3 is a core, 5 is an exposed part,
10 is a plug, 11 is an insulating base, 12 is a plug blade, 1
3 is a grounding rod, and 14 is a grounding terminal.

Claims (1)

[Claims] 1. A plug that has a plug blade on the outer surface of the insulating base that comes into contact with the conductor arranged on the inner surface of the wiring duct, and a grounding rod that contacts the exposed part of the metal core of the wiring duct and protrudes from the top of the insulating base. The grounding rod whose lower end contacts the upper surface of the grounding terminal mounted on the insulating base has spring elasticity in the vertical axial direction, and the lower end of the grounding rod is supported by the insulating base so as to be slidable only in the vertical direction. A grounded plug for wiring ducts.