JPH0322029B2 - - Google Patents

Description

[Detailed Description of the Invention] Generally, terminal devices for connecting conductors such as electric wires and punched conductive plates have a tightening screw screwed into the terminal fitting, and the conductor is tightened and connected by tightening the screw. There is.

By the way, when shipping from the factory, it is ideal to anticipate construction work in advance and loosen the tightening screws to the fullest extent, but the screws may come off during transportation.

Therefore, the screws are tightened so that they do not come off, and construction workers loosen the screws each time, insert the conductor, and then tighten the screws.However, when loosening the screws, the limit is unknown, and the work can be difficult if the screws are loosened too much. A screw sometimes fell out inside.

Particularly in the case of electrical equipment installed at high places, such as circuits and disconnectors, there was a problem in that it was difficult to judge the tightness of the screws.

Of course, there is a known example such as Japanese Utility Model Publication No. 43-23628, which aims only to prevent excessive loosening of screws, but this still causes damage to the threaded part of the tightening screw or screw hole, and furthermore, the synthetic resin There was a drawback that the molded container stand could break.

That is, in the above-mentioned known example, even if the tightening screw is loosened to the fullest extent, the threaded portion of the tightening screw and the screw hole are still screwed together. This is because the effective length of the tightening screw is longer than the distance when it is fully loosened.

Therefore, the tightening screw does not turn idly, and if it is loosened forcibly, both screw threads will be crushed, or if the screw threads overcome, the terminal fitting or the screw head will break the device base.

Of course, if the above two phenomena proceed without occurring, the tightening screw will open from the screw hole and come off, and the screw hole and the tightening screw will not match well during the next tightening, which will hinder re-screwing. .

The present invention has been made in view of the above-mentioned points. Namely, the screw hole of the terminal fitting is provided with a concave portion having a larger diameter than the threaded portion, and the threaded portion of the tightening screw and the threaded portion of the terminal fitting are connected. An obstacle part is provided that surrounds the outer periphery of the head of the tightening screw and comes into contact with the surface of the head in the removal direction when the screw is unscrewed and the threaded part of the tightening screw is located in the recess of the screw hole of the terminal fitting. This terminal device is characterized in that even when the tightening screw is loosened, the screw does not fall out of the screw hole, and furthermore, the screw portion is prevented from being damaged due to forceful loosening.

Hereinafter, the present invention will be explained based on FIGS. 1 to 3 showing one embodiment of the present invention. Reference numeral 1 denotes a terminal fitting, and a screw hole 2 is provided. This screw hole 2 is formed by a large diameter non-threaded recess 4 provided above the screw portion 3 of the screw portion 3. 5 is a tightening screw, terminal fitting 1
It consists of a threaded part 6 that is screwed into the threaded part 3 and a head 7 provided above the threaded part 6. 8 is a driver insertion hole located in the head 6, 9 is an obstacle provided in the insertion hole 8, and the lower end of the threaded portion 3 of the tightening screw 5 is located in the recess 4 of the screw hole 2 of the terminal fitting 1. The obstacle 9 surrounds the outer periphery of the head 7 of the tightening screw 5 and the head 6
Contact with the surface in the direction of withdrawal. Therefore, the tightening screw 5
When the threaded part 6 of the terminal fitting 1 is unscrewed from the threaded part 3 of the screw hole 2 of the terminal fitting 1, the threaded part 6 of the tightening screw 5 is located in the recessed part 3 of the terminal fitting 1, and its outer periphery is surrounded. The head 7 of the tightening screw 5 due to the above-mentioned obstacle 9
In addition to enclosing the outer periphery of the screw 5, the tightening screw 5 rotates idly when operated with a screwdriver.

Further, the obstruction portion 9 corresponding to the head 6 of the tightening screw 5 may be as follows depending on the structure of the terminal device, and these are arbitrary.

That is, FIGS. 1 to 3 show a terminal fitting 1 formed into a box shape, with upper and lower plates 10, 11 and both side plates 12 open at the front and back, and the front opening used to hold wires, metal plates, etc. A conductor inlet 13 is provided. The metal fitting 1 may be manufactured by bending a single metal plate and joining it at the lower plate 11 as in the embodiment, by cutting a rectangular pipe into pieces, or by casting. This terminal fitting 1 is housed in a main body 16 composed of a synthetic resin device stand 14 and a cover 15, and a screwdriver insertion hole 8 is provided in the cover 15.
5 myself. Further, a collar 17 is provided on the screw head 7 to improve the contact. 18 is the lower plate 1 of the metal fitting 1
This terminal board is mounted on item 1, but of course, depending on how it is made, it becomes unnecessary. In Fig. 4, the head 5 is applied directly without making a flange 17, and in Fig. 5, a presser foot 19 that moves up and down with the tightening screw 5 is placed under the screw head 7 on the obstruction part 9.
In this case, the terminal fitting 1 is simply a flat plate. In this case, an escape hole 20 for the screw 5 is bored in the device stand 14. In this case, the obstacle part 9 surrounds the outer periphery of the presser foot 19 and is in contact with the surface of the presser foot 19 in the withdrawal direction, and as in the embodiment, the obstacle part 9 indirectly
may surround the outer periphery of the head 7 of the tightening screw 5 and come into contact with the surface of the head 7 in the removal direction. In FIG. 6, the obstacle 9 is created using the terminal fitting 1 itself.
For installation, the driver insertion hole 8 has an end opening 21 larger than the outer diameter of the head 7, and the left and right side parts 22 are modified to narrow the width of the opening 21 so that the head 7 can come into contact with it.

As described above, the present invention provides the screw hole 2 of the terminal fitting 1.
A recess 4 with a larger diameter than the threaded part 3 is provided in the
The threaded part 6 of the terminal fitting 1 is unscrewed from the threaded part 3 of the terminal fitting 1, and the tightening screw 5 is removed when the threaded part 6 of the tightening screw 5 is located in the recess 4 of the screw hole 2 of the terminal fitting 1. Since the obstacle part 9 that surrounds the outer periphery of the head 7 and comes into contact with the surface of the head 7 in the withdrawal direction is provided, the tightening screw 5 is loosened and the threaded part 6 is screwed into the threaded hole 2 and the threaded part 3. When the screw comes loose, the head 7 is prevented from falling off in the advancing direction of the screw as it hits the obstacle 9, and lateral vibration is prevented by surrounding the head 7 with the obstacle 9 and surrounding the threaded part 6 with the recess 4. Therefore, the tightening screw 5 only rotates idly, and the screw thread will not be crushed due to forcible loosening as in the known example, and the molded product to which the terminal device is attached will not be cracked, and the wires and bolts will not be damaged. This has the effect of making it easier to connect conductors such as extraction plates.

[Brief explanation of the drawing]

Figures 1 to 3 show an embodiment of the terminal device of the present invention, with Figure 1 being a front view, Figure 2 being a sectional view,
FIG. 3 is an exploded perspective view, and FIGS. 4 to 6 are views of different embodiments. 1... Terminal fitting, 2... Screw hole, 3... Threaded part, 4... Recessed part, 5... Tightening screw, 6... Threaded part, 7... Head, 8... Driver insertion hole, 9 ……
Obstacle part, 10... Upper plate, 11... Lower plate, 12...
Side plate, 13...Inlet, 14...Dish stand, 15...
Cover, 16... Main body, 17... Tsuba, 18... Terminal board, 19... Presser foot, 20... Relief hole, 21...
...opening, 22...side.

Claims (1)

[Claims] 1. A terminal fitting having a threaded part and a threaded hole having a recess with a larger diameter than the threaded part provided above the threaded part;
A tightening screw consisting of a threaded portion screwed into the threaded portion of the terminal fitting so as to be freely retractable and a head provided above the threaded portion, and a screw thread between the threaded portion of the tightening screw and the threaded portion of the terminal fitting. an obstacle portion that surrounds the outer periphery of the head of the tightening screw and comes into contact with the surface of the head in the removal direction when the screw is uncoupled and the threaded portion of the tightening screw is located in the recess of the screw hole of the terminal fitting; A terminal device characterized by comprising: