JPH0324727Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention relates to nails that are driven into soft boards such as ALC materials (lightweight aerated concrete products) and gypsum boards.

[Conventional technology]

As a conventional technology for driving nails into ALC materials,
For example, as shown in FIGS. 7 and 8, the shaft portion 3
A head 31 is formed at the rear end of the shaft part 30, and the shaft part 30 is divided into two parts along the axis, and an axial groove 33 is formed on the inner surface of the two bits 32, 32 obtained by the division. There is one in which a tapered surface 34 is formed on the inner surface of the tip end of each bit 32, and a head 36 for expanding the diameter of the bit is provided at the tip of a shaft-shaped plug 35 held by the tip end of each bit 32. .

When a nail with the above structure is driven into the ALC material 40, the shaft portion 30 smoothly enters the ALC material 40, and the plug 35 also enters together due to contact with the bit 32 that constitutes the shaft portion 30. However, since the driving resistance acting on the plug head 36 is greater than the above-mentioned contact force, there is a difference in the penetration speed between the two, and due to the difference in penetration speed, the plug 35 enters the inside of the shaft portion 30. Become. As a result, bit 32
are pushed open by the plug head 36 and penetrate into the ALC material 40 while expanding outward. For this reason,
The engagement force of the bit 32 to the ALC material 40 is strong,
The engagement force can prevent the nail from coming off.

[The problem that the idea aims to solve]

By the way, in the above conventional nail, bit 3
In order to facilitate the outward expansion of the bits 2, the bits 32 are made of a soft material such as aluminum,
On the other hand, since the plug 35 is made of a hard material such as iron, the plug 35 is made of a hard material such as iron.
Each bit 32 expanded outwardly with a head 36 of 5
In many cases, the intrusion expands outward without being subjected to the diameter-expanding action of the head 36. In this case, when the nail is fully driven,
If there is a gap between the plug head 36 and the inner surface of the bit 32 and a large pullout stress is applied to the nail, each bit 32 will come out without holding the plug head 36, making it easier to pull out.

Furthermore, even in the ideal driving state where the plug head 36 contacts the inner surface of the bit 32, the bit 32
Since the nail is soft, the pull-out stress acting on the nail deforms the bit 32 inward using the contact area on the outer periphery of the plug head 36 as a fulcrum, as shown by the chain line in FIG. 7, and the pull-out strength decreases. It has the disadvantage of being weak.

Therefore, the technical objective of this invention is to eliminate the above-mentioned disadvantages and improve the pull-out strength.

[Means to solve the problem]

In order to solve the above problems, in this invention, a plurality of rod-shaped bits are assembled to form a shaft part, a head is provided at the rear end of the shaft part, and an axial groove is formed on the inner surface of each bit. A tapered surface is provided on the inner surface of the tip of each bit, a head for expanding the diameter of the bit is formed at the tip of the plug held by the tip of each bit, and each bit is made of a hard material. However, a structure is adopted in which a plurality of engagement grooves into which the head of the plug can be engaged are provided on the inner surface of the bit at required intervals in the length direction of the bit.

[Effect]

When a nail with the above configuration is driven into ALC material,
The bit and plug enter the ALC material together, but
Since the driving resistance acting on the bit is smaller than the driving resistance acting on the plug, there is a difference in the penetration speed of the two, and the plug penetrates into the interior of the shaft.

Furthermore, since the bits are made of a hard material, each bit enters the inside of the ALC material while always being in contact with the outer periphery of the head of the plug. For this reason, the bit receives a wedge action from the plug head and moves while expanding outward, while the plug does not penetrate deeply into the shank due to contact with the bit, and when the nail is completely driven, the shank moves. Located in the center, the head of the plug engages with the engagement groove.

〔Example〕

Hereinafter, embodiments of this invention will be described based on FIGS. 1 to 6.

As shown in FIGS. 1 and 2, the shaft portion 1 is
It consists of an assembly of a plurality of rod-shaped bits 2, and a head 3 is provided at the rear end of the shaft portion 1.

The bit 2 is made of a hard material such as stainless steel. The cross-sectional shape of the bit 2 when cut in the horizontal direction is fan-shaped, and an axial groove 4 is provided on the inner surface thereof. Further, a tapered surface 5 is formed on the inner surface of the tip end of each bit 2, and due to the formation of the tapered surface 5, the tip of the bit 2 becomes sharp, thereby reducing the driving resistance.

Furthermore, in the center of the inner surface of the bit 2, there is the groove 4.
A plurality of engagement grooves 7 extending across the bit 2 are provided at required intervals in the length direction of the bit 2.

A washer 6 is slidably provided on the outside of the tip of the shaft portion 1, and a shaft-shaped plug 10 is held at the tip of the bit 2, which is prevented from expanding outward by the washer 6. There is. The hardness of the plug 10 is softer than that of the bit 2, and the plug 10 is made of iron, brass, plastic, or the like. A step 11 is provided in the center of the plug 10, the outer peripheral edge of the step 11 abuts the tapered surface 5 of the bit 2, and the small diameter shaft portion 12' at the tip is located within the groove 4 on the inner surface of the bit. Both side edges of the groove 4 abut against the outer periphery of the small diameter shaft portion 12'.

Further, a circular head 12 is provided at the rear end of the plug 10, and the outer periphery of the head 12 abuts against the tip of the tapered surface 5 of the bit 2.

Now, as shown in FIG.
enters, and the washer 6 comes into contact with the surface of the ALC material 20.

Furthermore, when driving a nail, the difference in the driving resistance acting on the bit 2 and the driving resistance acting on the plug 10 causes a difference in the penetration speed of the bit 2 and the plug 10 into the ALC material 20, and the plug 10 penetrate inside.

Further, since the bit 2 is hard, the bit 2 enters the inside of the ALC material 20 while being in contact with the outer periphery of the head 12 of the plug 10. Therefore, the bit 2 penetrates into the ALC material 20 while expanding outward due to the wedge action of the head 12, while the plug 10 enters the shaft portion 1 due to contact with the bit 2.
When the nail is completely driven into the shaft without penetrating deeply into the inside of the plug, the nail is located at the center of the shaft 1 and the head 12 of the plug 10 is engaged with the engagement groove 7, as shown in FIG. do.

As mentioned above, when the nail is completely driven, the head 12 engages with the engagement groove 7, so when a force in the pulling direction is applied to the shaft 12, the bit 2 securely holds the head 12 of the plug 10. As a result, the bit 2 can be held in place to prevent it from deforming inward.

Further, since the plug 10 is located in the center of the bit 2, the tip of the bit is strong and does not easily deform inward. Therefore, it is possible to obtain an extremely large pull-out strength, which is effective in preventing the nail from being pulled out.

Incidentally, since the head 12 of the plug 10 is softer than the bit 2, a burr 13 is generated on the outer periphery of the head 12 due to relative movement between the bit 2 and the head 12.
This burr 13 engages with the inner surface of the bit 2 when the head 12 of the plug 10 does not engage with the engagement groove 7, and this engagement prevents the bit 2 from moving in the withdrawal direction. Therefore, even if the head 12 does not engage with the engagement groove 7, it is possible to effectively prevent the bit 2 from being pulled out.

As shown in FIG. 5, by applying the latex registered trademark 8 between the abutting surfaces of the bits 2 and the space formed by each bit 2, a part of the latex registered trademark 8 will be removed when the nail is being driven. is the 6th
As shown in the figure, since it bulges on the outer periphery of the surface of the plug head 12, it is possible to increase the engagement force between the plug head 12 and the inner surface of the bit 2 in the direction of preventing it from coming off.

[Effect of idea]

As mentioned above, in the nail according to this invention,
Since the bit is made of a hard material, the bit can be prevented from expanding outward and penetrating into the ALC material without receiving the wedge action of the plug.

For this reason, when driving into ALC material,
The engagement groove of the bit engages with the outer periphery of the head of the plug, and the plug is located in the center of the bit, and the tip of the bit located in front of the plug has a waist, so the bit expands outward. It is possible to reliably prevent inward deformation of the material, and to obtain extremely high pull-out strength.

[Brief explanation of the drawing]

FIG. 1 is a partially cutaway front view showing an embodiment of the nail according to the invention, FIG. 2 is a cross-sectional plan view of the same, and FIG. 3 is a partially cutaway sectional view showing the driving state of the same nail. FIG. 4 is an enlarged sectional view of a portion of the above nail, FIG. 5 is a partially cutaway front view showing another embodiment of the nail, and FIG. 6 is an enlarged sectional view of a portion of the nail as shown in the driving state. FIG. 7 is a vertical sectional front view showing a conventional nail, and FIG. 8 is a sectional view taken along the - line in FIG. 7. 1...Shaft part, 2...Bit, 3...Head, 4...
...Groove, 5...Tapered surface, 10...Plug, 12...
…head.

Claims (1)

[Scope of utility model registration request] A plurality of rod-shaped bits are assembled to form a shaft, a head is provided at the rear end of the shaft, an axial groove is formed on the inner surface of each bit, and a tapered surface is formed on the inner surface of the tip of each bit. A head for expanding the diameter of the bit is formed at the tip of the plug held by the tip of each bit, and each of the bits is made of a hard material, and the head of the plug is engaged with the inner surface of the bit. A nail with a plurality of engagement grooves spaced apart from each other in the length direction of the bit.