JPH0545218U - screw - Google Patents

Abstract

(57) [Summary] [Purpose] To provide a screw that can save the labor of forming a spot facing and simplify the driving operation. [Structure] Four convex portions 18 having a regular triangular cross section, which are cutting portions, are formed on the back surface 17 of the head 13 of the wood screw 11 from the upper portion to the lower portion at intervals of 90 degrees. Thus, when the screw 11 is driven while rotating the screw 11 using the screwdriver 15, when the head 13 reaches the wood 19, at the same time when the screw 11 is driven, the convex portion 18 is made into wood.
The counterbore 20 is formed by cutting 19.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention relates to screws, and can be used for wood screws and the like.

[0002]

[Background technology]

 For example, when a wood screw is driven into wood or the like, inconvenience occurs if the head of the screw remains protruding from the wood surface. Therefore, usually, a counterbore is formed in the wood where the wood screw is to be driven beforehand by using a drill so that the head of the wood screw is flush with the surface of the wood.

[0003]

[Problems to be solved by the device]

 Conventionally, when a large number of wood screws are driven into wood, a large number of counterbores must be formed according to the number of wood screws, which is troublesome and inefficient. Then, this invention aims at providing the screw which can save the trouble of forming a spot facing.

[0004]

[Means for Solving the Problems]

 The screw according to the present invention is characterized in that an uneven cutting portion is formed on the back surface of the head from the upper part to the lower part of the back surface. The shape of the concave-convex cutting portion is arbitrary, and for example, it can be a continuous convex portion having a regular triangular cross section, a conical convex portion, or the like. Further, the number of these cut portions is arbitrary as long as it is formed continuously or discontinuously from the upper part to the lower part of the back surface, and the number thereof should be set so that the spot facing can be formed reliably and easily. Good.

[0005]

[Action]

 Since the screw according to the present invention has an uneven cutting portion on the back surface of the head, when driving while rotating the screw, when the head reaches the wood etc., the cutting portion is cut at the same time when the screw is driven. Will cut wood etc., and a spot facing will be formed. Therefore, a separate counterbore forming operation becomes unnecessary.

[0006]

【Example】

 A first embodiment in which the present invention is applied to a wood screw 11 will be described with reference to FIGS. As shown in the figure, the wood screw 11 according to the present embodiment is configured to include a screw portion 12 and a head 13 thereof.

The head 12 is of a flat type, and a flat surface 14 is formed with a slit 16 through which a tip of a screwdriver 15 is fitted, and a taper rear surface 17 of the present embodiment is formed. A convex portion 18 which is a cutting portion according to the example is formed. As shown in FIG. 3, the convex portion 18 has an equilateral triangular cross section, and is continuously formed in a straight line from the upper portion to the lower portion of the back surface 17. For example, a total of four convex portions 18 are formed on the back surface 17 at intervals of 90 degrees.

When such a wood screw 11 is used, as shown in FIG. 4, when driving the screw 11 while rotating the screw 11 as usual, the head 13 reaches the wood 19. At that time, the convex portion 18 cuts the wood 19 at the same time as the screw 11 is driven, and the spot facing 20 is formed.

According to the wood screw 11 according to the above-described embodiment, the convex portion 18 formed on the back surface 17 cuts the wood 19 to form the counterbore 20 at the same time when the screw 11 is driven. No need for formation work. Therefore, by using the wood screw 11 according to the present embodiment, the driving operation of the screw 11 can be simplified.

Further, since the convex portion 18 can be formed at the same time when the wood screw 11 is manufactured, the wood screw 11 according to this embodiment can be easily manufactured.

Next, a wood screw 11 according to a second embodiment of the present invention will be described with reference to FIGS. The wood screw 11 according to this embodiment has a head portion 13 having a back surface 17 on which a convex portion 21 as a cutting portion is formed. The convex portion 21 has a conical shape, and a plurality of convex portions 21 are formed discontinuously from the upper side circumference to the lower side circumference of the back surface 17.

The array of these convex portions 21 is a first array 21A in which two convex portions 21 are formed apart from each other in the longitudinal direction of the back surface 17 shown in FIG. 5, and this first array 21A is a circle. The protrusions 21 are formed at equal intervals in the circumferential direction, and the three convex portions 21 are separated from each other between the first arrays 21A so as to be located between the first arrays 21A in the longitudinal direction of the back surface 17. There is a second sequence 21 B formed in this way. In the case of this wood screw 11 as well, by using it in the same manner as the wood screw 11 according to the above-mentioned embodiment, when the head 13 reaches the wood 19, the convex portion 21 cuts the wood 19 at the same time when the screw 11 is driven, The spot facing 20 is formed (see FIG. 4).

In the first embodiment, the convex portion 18 is formed linearly from the upper portion to the lower portion of the back surface 17, but as shown in FIG. 7, the convex portion 22 may be formed in a curved shape, for example. You may choose. Further, in the first embodiment described above, the cross section of the convex portion 18 which is the cutting portion is an equilateral triangle, but this cross sectional shape is arbitrary. For example, as shown in FIG. As shown in FIG. 9, the convex portion 24 may have a quadrangular shape.

Further, in the above-mentioned first and second embodiments, all the cutting portions are formed in a convex shape, but as shown in FIG. 10, for example, a concave portion 25 having an equilateral triangular cross section is formed continuously, and these are formed. The spot facing 20 may be formed by the convex portions 26 between the concave portions 25. Furthermore, although the screw according to the above-described embodiment is the case of the wood screw 11, the present invention can be similarly applied to a screw other than the wood screw.

[0015]

[Effect of the device]

 According to the screw of the present invention, it is possible to save the trouble of forming a spot facing and to simplify the driving operation.

[Brief description of drawings]

FIG. 1 is a side view of a wood screw according to a first embodiment of the present invention.

FIG. 2 is a bottom view of the wood screw of the embodiment.

FIG. 3 is a cross-sectional view of the wood screw of the same embodiment.

FIG. 4 is a cross-sectional view showing a wood screw driving operation of the embodiment.

FIG. 5 is a side view of a wood screw according to a second embodiment of the present invention.

FIG. 6 is a bottom view of the wood screw of the embodiment.

FIG. 7 is a bottom view of the wood screw showing another embodiment of the convex portion which is the cutting portion.

FIG. 8 is a cross-sectional view of a main part of a wood screw showing another embodiment of the convex portion which is the cutting portion.

FIG. 9 is a cross-sectional view of essential parts of a wood screw showing another embodiment of the convex portion which is the cutting portion.

FIG. 10 is a sectional view of an essential part of a wood screw showing another embodiment of the cutting part.

[Explanation of symbols]

 11 Wood screw 12 Screw part 13 Head part 14 Front surface 17 Back surface 18,22,23 Convex part that is a cutting part 21 Convex part that is a cutting part 24 Recessed part that is a cutting part

Claims (1)

[Scope of utility model registration request] 1. A screw characterized in that an uneven cutting portion is formed on the back surface of the head from the upper part to the lower part of the back surface.