JPS6033844A - Production of screw nail - Google Patents

Abstract

PURPOSE:To make inexpensive mass production of a screw nail provided with detaining grooves by subjecting a shaft member provided with plural ridge parts in the axial direction of multiple circumferential surfaces to twisting around the axial center in such a way that the parts between the adjacent ridge parts acts as screw threads and to forming of plural detaining grooves to the respective ridge parts. CONSTITUTION:A shaft material 11 is subjected to twisting around the axial center thereof to form the spiral shaft material 11a of which the parts between the respective ridges 12 act as screw threads 5 of a large lead angle. Detaining grooves 6 are then formed to the respective ridges 12 of the material 11a by working means such as machining, rolling, pressing or the like so that the grooves are allayed on the same circumference and are arrayed axially at predetermined intervals. The material 11a formed with the grooves 6 is subjected to a general nail manufacturing stage, by which the material 11 is cut, the head part 4 is formed and a pointed end 2 is formed. The screw nail 1 is thus continuously produced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a screw nail, and more particularly to a method of manufacturing a nail having a plurality of locking grooves in the crest of a multi-thread screw by twisting.

A screw nail with a multi-start screw with a large lead angle formed on the outer circumferential surface of the shaft enters the nailed object while forming a driving hole that matches the cross-sectional shape of the shaft, so it can be driven smoothly. However, since the above-mentioned screw nails are simply formed with a continuous screw, the driving hole and the outer surface of the shaft are There is a problem in that the screws are easily guided in the direction of loosening in the driving hole, and loosening is likely to occur when vibration or the like occurs.

In order to solve this problem with screw nails, we created a nail with multiple locking grooves on the top of the screw.
Proposed by No. 8329.

In the above screw nail, the horizontal hooking groove provided in the crest of the screw causes the shaft portion to catch on the nailed object.
The latching groove completely prevents it from loosening, and even materials with low shrinkability such as plywood can be securely fixed.

The purpose of the present invention is to provide a manufacturing method that can inexpensively mass-produce screw nails equipped with the above-mentioned retaining grooves. The shaft center is centered on the shaft material so that a screw groove is formed between adjacent ridges, and then the shaft material is hammered.

DESCRIPTION OF THE PREFERRED EMBODIMENTS This invention will be explained below based on embodiments shown in the accompanying drawings.

FIG. 4 shows the completed screw nail 1, in which a head 4 is formed at the upper end of the shank 3 whose lower end becomes the sharp end 2, and the shank 3
A plurality of screws 5 having a large lead angle are provided on the outer peripheral surface of the screw, and a large number of latching grooves 6 are arranged horizontally and at regular intervals in the axial direction in the trailing portion between each screw. It is composed of

The above-mentioned latching groove 6 has an inclined circumferential surface 6a that gradually slopes outward toward the upper end, and an inclined circumferential surface 6a that extends from the upper edge of this circumferential surface toward the axis Z of the shaft portion 3 and is substantially perpendicular to the axis. The inner end of the latching step 6b is located at the lower end of the upper inclined circumferential surface 6a.

Each of the locking grooves 6, which gradually deepen toward the tip of the shaft portion 3, is formed such that the diameter of the small diameter portion at the lower end of the inclined circumferential surface 6a is approximately equal to the diameter of the root of the screw 5. Each ridge has a shape that is interrupted at six valleys in the circumferential direction.

1 to 3 show the manufacturing process of the screw nail described above.

FIG. 1 shows an example of a shaft material 11 that is a material for a screw nail, and has a cross-sectional shape with a plurality of ridges 12 on the outer circumferential surface. In addition to a polygonal shape, a cross-sectional shape in which the ridges 12 are visible can be adopted.

The shaft member 11 is twisted around its axis to form a helical shaft member 11a in which a screw groove 5 with a large lead angle is formed between each ridge portion 12, as shown in FIG.

The above-mentioned spiral shaft material 11ai is cut, rolled, pressed, etc. as shown in FIG. Formed by processing means.

In the illustrated example, the retaining groove 6 is rotated around the spiral shaft member IC, but the retaining groove 6 is first formed on the ridge 12 of the shaft member 11 before being twisted. After this, the helical shaft member 11a may be formed by twisting.

If the helical shaft material 11a provided with the above-mentioned latching groove 6 is subjected to the general bag punching process, the shaft material is shredded, the head 4 is formed, and the sharp end 2 is formed, the result as shown in FIG. 4 is obtained. The screw nails 1 will be completed continuously.

As described above, according to the present invention, a shaft member having a cross-sectional shape with ridges around the periphery is twisted to form a screw groove between each ridge, and each ridge is provided with a large number of retaining grooves. Since the screw nails are rear-loaded, it is possible to efficiently manufacture screw nails having a multi-thread screw and a locking groove in the crest thereof, and it is possible to reduce the system cost by mass producing the screw nails.

[Brief explanation of drawings]

Figure 1 is a perspective view of the shaft material that is the raw material, Figure 2 is a perspective view of the same shaft with twisting, Figure 3 is a front view with a retaining groove added, and Figure 4 is the finished product. FIG. 1 is the screw nail, 2 is the sharp end, 3 is the shaft, 4 is the head,
5 is a screw, 6 is a retaining groove, 11 is a shaft member, and 12 is a ridge.

Claims (1)

[Claims] A shaft material with a cross-sectional shape with multiple twills on the outer circumferential surface is twisted around the shaft center so that the adjacent twills form screw grooves, and multiple latching grooves are provided on each ridge. A method for manufacturing screw nails, characterized by manufacturing the nails using wood.