JPH0117687Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an auxiliary plate that increases the pull-out strength of square nails that are commonly used in fixing devices for lightweight aerated concrete.

Conventionally, when attaching articles to lightweight cellular concrete, square nails 1 shown in FIG. 1 have often been used.

However, due to its structure, the pull-out force is obtained by pressure contact between the lightweight aerated concrete and the tapered surface 2, so
The drawback is that the pulling force decreases rapidly due to vibration or slight loosening, and its use has been limited to temporary fixing.

Proposals have been made to increase the pulling force of square nails, such as providing the nail with a leg plate or splitting the nail into multiple legs.

Figure 2 shows one of those proposals, square nail 1.
An auxiliary plate 3 formed in the shape of a U-shape is attached. As mentioned above, the square peg 1 has a tapered surface 2 formed thereon, and a space 4 is created between this tapered surface 2 and the auxiliary plate 3. When this combination is poured into lightweight cellular concrete, the lightweight cellular concrete 5 enters through the gap a and the auxiliary plate 3 is expanded as it is poured, as shown in FIG.
However, in this case, sufficient pulling force cannot be obtained.
This is because the gap a at the tip is too wide, so a×b
The lightweight cellular concrete 5 that has entered the space remains almost in a bubble state. When lightweight cellular concrete remains in a cellular state, when pressure is applied locally, the bubbles collapse and the volume becomes considerably smaller. In other words, during driving, the auxiliary plate 3 enters the concrete while opening its legs without breaking the air bubbles in the concrete, and when a pull-out force is applied in the direction of the nail head, an external pressure is applied that closes the square nail 1 and the auxiliary plate 3. , the concrete between the auxiliary plate 3 and the square nail 1 is compressed, the air bubbles left in the concrete collapse, and the volume of the concrete between the auxiliary plate 3 and the square nail 1 at the time of pouring is reduced, forming a hard lump. It takes a considerable distance to pull out the material, making it impossible to obtain the initial pull-out strength and causing loosening.

The present invention is a new structure devised for the purpose of solving the above-mentioned drawbacks of the device shown in FIG. 3, and furthermore obtaining a fastener with a high pulling force as described above.

The configuration of the present invention will be explained according to the drawings.

As shown in FIG. 4, a metal thin plate is formed into a U-shaped cone, and the bottom wall surface 7 thereof is an inclined surface whose depth gradually becomes shallower toward the tip in the middle excluding both ends. 8 is formed, and the flat parts at both ends of the bottom wall surface are configured to have different depths.

This inclined surface 8 is formed to have almost the same degree of inclination as the tapered surface 2 of the square nail 1, and its length is shorter than the length of the tapered surface 2 of the square nail 1, and usually about 1/2 is appropriate. It must not be the same length as the tapered surface.

As shown in FIG. 4, since the inclined surface 8 is configured to be shorter than the tapered surface 2, when the auxiliary plate 6 of the present invention is attached to the square nail 1, the tapered surface 2 of the square nail and the auxiliary plate 6 The gap c formed between the flat part 9 of the bottom wall surface on the tip side of the plate is considerably narrower than the conventional gap a shown in FIG. It becomes smaller, usually about 1/4 of the size.

As shown in FIG. 5, during driving, the auxiliary plate 6 of the present invention compresses the concrete that falls between the auxiliary plate 6 and the square nail 1 by the inclined surface 8 of the auxiliary plate 6, and advances while breaking the air bubbles in the concrete. Therefore, by making the concrete between the auxiliary plate 6 and the square nail 1 into a solid lump, when a pulling force is applied in the direction of the nail head, the external pressure applied to the auxiliary plate 6 causes the auxiliary plate 6 and the square nail 1 to break apart. The volume of the concrete in between does not shrink, and the initial pull-out strength is obtained without loosening.

Further, a compressive force is applied from the direction e to the outer wall surface of the inclined surface 8, and around this area, the square nails 1, the auxiliary plate 6, and the lightweight cellular concrete 11 are all tightly adhered without any extra gaps or bubbles.

It has been known for a long time that the U-shaped auxiliary plate surrounds the concrete with the square nails 1 and the auxiliary plate 3, preventing the applied pressure from spreading to the surrounding area. Auxiliary board 6
According to the above-mentioned novel structure, the pressure retained here can be effectively converted into pull-out strength.

Another way to reduce this space in advance is to reduce the tapered surface 2 of the square nail 1, but in this case, the square nail itself must be manufactured anew, which increases the cost, and the tapered surface In order to reduce the size, the flat end portion 12 shown in FIG. 1 becomes large, and the resistance received from the lightweight aerated concrete during pouring becomes too large, resulting in a problem that it is difficult to pour.

As described above, according to the present invention, it is possible to form a strong adhesion state inside the lightweight cellular concrete using the conventional general square nails, and to obtain the effect that the pull-out strength can be increased.

Fig. 6 shows another embodiment of the present invention, in which a tapered portion 13 is provided on the tip side of a thin metal plate bent into a U-shaped cone shape, thereby making it easier for the auxiliary plate of the present invention to spread. It is particularly suitable for use with highly foamed concrete construction materials and other soft construction materials, and has a claw 14 near the head side that is slightly bent toward the bottom wall surface so that when combining with a square nail, the head of the inserted square nail The claws 14 can also bite into the body directly below the body to prevent them from falling off easily. Furthermore, an auxiliary head 15 may be provided at the end on the head side, which spreads out in a shape of a ripple. When driving in combination with a square nail, and attaching the article to lightweight aerated concrete, the article is attached to the auxiliary head 15 and square. It is pressed together with the head 16 of the nail, and when a pulling force is applied, it has the effect that it will not come out unless the auxiliary board 6 and the square nail 1 of the present invention combine and come out.

[Brief explanation of drawings]

Figure 1 is a perspective view of a conventional square nail, Figure 2 is a cross-sectional view of an example of a combination of a conventional square nail and a U-shaped auxiliary plate, Figure 3 is a cross-sectional view of the same after driving, Figure 4 is a cross-sectional view showing an example in which the auxiliary plate of the present invention is combined with a square nail, and Figure 5 is a cross-sectional view after the same is driven.
FIG. 6 is a perspective view showing another embodiment of the auxiliary plate of the present invention. 1... conventional square nail, 2... tapered surface, 6... auxiliary plate of the present invention, 8... inclined surface, 9... flat surface on the tip side, 10... narrow space on the tip side, 11... the same Lightweight aerated concrete compressed into space.

Claims (1)

[Scope of utility model registration request] For the auxiliary plate to be attached to a square nail with an inclined surface on one side, a thin metal plate is formed into a U-shaped trough shape, and it is tightly attached along the slope of the square nail at the middle point of the bottom wall of the auxiliary plate excluding both ends. An auxiliary plate for square nails that has an inclined surface, flattened ends, and different depths.