JPH0932826A - Set screw for construction board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a set screw for a construction board in which the screw can be favorably threaded to set a head of the set screw at the same level with the surface of the board without generating floating or fluffing of board surface material. SOLUTION: A set screw comprises a threaded part 1 and a head 2, a cut part is formed at a tip of the threaded part to cut and eliminate surface material of a board, a lower part of the head 2 is formed as conical shape directed to the threaded part 1, and plural blades are formed at this conical part 6. A flat circular presser surface 8 is formed between the conical part 6 and the periphery of the head 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention is for fixing various building boards such as gypsum board, papermaking fiber gypsum board, gypsum fiber board, calcium silicate board, etc. to the base surface or fixing the stacked boards. Regarding the set screw used.

[0002]

2. Description of the Related Art Taking a gypsum board as an example, it is widely used as an interior material from the viewpoint of fireproofness, sound insulation and workability. The gypsum board is generally attached to the ground surface by using a set screw, and the set screw is also used to firmly integrate the laminated board.
Since the interior finish is done by applying cloth or painting on the gypsum board, the set screw is screwed in so that its head retracts somewhat from the surface of the gypsum board, and the plaster putty is put in the recessed part. The surface of the board is usually smoothed by painting.

[0003]

[Problems to be Solved by the Invention] When the set screw is screwed into the gypsum board, the plaster forming the core of the gypsum board moves in the direction opposite to the entering direction of the set screw as milling powder due to the action of the screw thread of the set screw. That is, there is a drawback in that the surface material that is lifted up causes swelling and fluffing of the surface material that constitutes the board surface. Usually, it was necessary to remove such raised portions and fluff before the smoothing treatment with putty. Other boards had similar problems as long as they used conventional setscrews. The purpose of the present invention is
An object of the present invention is to provide a set screw for a construction board, which can be screwed in properly so that the head of the set screw is flush with the surface of the board without causing swelling or fluffing of the surface material of the board.

[0004]

The object of the present invention is to provide a set screw having a threaded portion and a head, and at the tip of the threaded portion, a cutting portion for cutting into the surface material of the board and scraping it off. Formed, the lower part of the head is conical towards the threaded part and multiple blades are formed in this conical part, and the head has a flat annular pressing surface between the conical part and the periphery of the head It is achieved by providing a set screw for a construction board, characterized in that The set screw has a pyramid portion formed at the tip thereof so as to be cut into the surface material of the board and scraped off. In another example, a conical portion is formed at the tip of the set screw, and the conical portion is formed with a blade configured to cut into and scrape the surface material of the board. The blade may include a simple protrusion, and the surface material may be scraped off. In yet another example, the threads continue to the tip of the set screw, where the tip is formed with a notch that constitutes a blade adapted to cut into and scrape the surface material of the board. .

The position of the notch may be the tip and / or the portion with the main screw thread. Further, the cutout portion is not necessarily cut out from the tip of the cutting portion, and at least from the tip.
By notching at a distance of 1 mm, the strength at the most apex is not lowered, and the plaster board surface and further the base material for fixing the board are well bited, and the strength reduction due to the notch does not hinder the penetration of the screw. The threaded portion may be formed from either the cutting portion or the tip thereof, and may be only the main thread provided up to the conical portion below this.
Further, the threaded portion can be provided with a sub-thread having a pitch smaller than the pitch of the main thread between the conical portion below the head and the main thread. That is, the thread-like inclination of the auxiliary thread is smaller than the inclination of the main thread. Further, the sub-thread can be a double thread, and further, the inclination of the sub-thread can be the same as the inclination of the main thread and can be a double thread. By doing either of the above, when the screw enters the gypsum board, the sub-thread suppresses the surface material and plaster from rising due to the main thread, and the surface material, etc. The blade is effectively hit, the cutting effect is further enhanced, and the swelling of the surface material is suppressed.

Further, the threaded portion may be configured such that only a body portion having no thread having a diameter smaller than the diameter of the main thread is provided between the conical portion below the head and the main thread. . By doing so, the gypsum rising by the main screw thread enters the space around the body, and the rise of the surface material is further suppressed.
Furthermore, the main thread can be a double thread. It should be noted that when the main screw thread is a single thread, it is effective in improving the holding force of the wood base and the board and the like, but when the base is made of steel, the main thread is a double thread. There is an effect that the work of fastening the board to the steel material with the screw becomes easier.

[0007]

When the gypsum board is fixed to the ground surface, the set screw according to the present invention is screwed into the gypsum board using a screwdriver. First, the tip-shaped blade cuts into the surface material of the gypsum board to powder the material. It is then scraped off, then enters the core of the gypsum board, and the lead screw threads through the gypsum that makes up the core, as usual. At this time, the gypsum of that part is moved as a milling powder in the direction opposite to the direction of entry of the screw thread into the gypsum, and as a result, the milling powder is gradually discharged from the surface of the gypsum board, but the surface material is partially The release of gypsum powder from the outside continues to be suppressed. Whether the sub-thread smaller than the pitch of the main screw holds down the plaster rising by the main screw as the screw further enters the gypsum board,
If the sub-thread is only the body that is smaller than the diameter of the main thread without the thread, the gypsum rising from the main thread enters the space around the body. At this time, in each case, the plaster rise is reduced, and the rising plaster effectively hits the blade in the conical portion below the head effectively, and the blade causes the rising plaster to be cut, and the surface material is raised. Suppress. Then, the conical part of the head pushes the rest of the surface material and plaster into the board while the blade scrapes off the surface material and the plaster underneath by the screwing rotation of the screw, but the remaining surface material part is still cut. It is pressed on the board by the flat pressing surface of.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, a set screw according to the invention has a threaded portion 1 and a head 2 with a cross groove for the driver on its upper surface. The threaded portion 1 includes a pyramidal portion 3A, which is a cutting portion 3, at the tip of the set screw in order to facilitate cutting of the set screw into the surface material of the gypsum board. The pyramidal portion 3A may be a triangular pyramid or an octagonal pyramid, but as shown, it is preferably a quadrangular pyramid. The threaded portion 1 is a main thread 4 formed from the pyramid portion 3A.
And a sub-thread 5 formed between the end of the main thread 4 and the head 2. The sub-thread 5 is a double thread, and the length of the sub-thread 5 is preferably about 1/4 of the length of the main thread. The pitch of one thread of the double thread is the same as the pitch of the main thread, and the other thread of the double thread is formed in the center between the one thread. The heights of the secondary and primary threads are equal.

The lower part of the head 2 is conical towards the threaded part, this conical part 6 being provided with a plurality of blades 7 along its conical surface and the head being conical part thereof. A flat annular holding surface 8 is formed between 6 and the periphery of the head. The diameter of the screw thread varies depending on the type of base material, but 3.5 mm to
It is 5.5 mm. The cone angle of the conical portion 6 is between 40 ° and 100 °, preferably between 60 ° and 90 °, 40 °
If it is below, it is difficult to push in dust and the like, and if it is 100 ° or more, it is not easy to scrape off the board material with a blade, and the head is difficult to get into the board. The blades 7 have a height of 0.1 mm to 1 mm, the number of which is at least two, but in the illustrated embodiment it is twelve, as can be seen in FIG. The annular holding surface 8 has a width of 0.2 mm to 1 mm, preferably 0.5 mm for optimum holding.

The set screw according to the present invention is screwed into the gypsum board by using a screwdriver so that the gypsum board is inserted into the base surface, and thereby the gypsum board is fixed to the base surface. At this time, the pyramid part 3
First, A cuts into the surface material of the gypsum board and grinds it into powder, thus suppressing fuzzing of the surface material and facilitating screwing of the main screw thread 4 into the surface material of the gypsum board. The main thread 4 enters the board by such screwing, and advances through the plaster forming the core. When the main screw thread 4 is screwed and rotated, the gypsum in that portion becomes milled powder and is moved in the direction opposite to the direction in which the thread thread enters the plaster, and the milled powder is released to the outside, but some milled powder is released. Gradually raise the surface material of the gypsum board. However, the sub-thread 5 reaches the raised part of the board, and the sub-thread 5 is screwed into the gypsum board by the further entry of the screw into the gypsum board.
At this time, the sub-thread does not cause the raised surface material to rise further. Then, the conical portion 6 of the head 2 pushes them into the board while the blade 7 acts as a reamer by the rotation of the screw to scrape off the surface material and the plaster below it. The scraping off of the material by the blade enters into the board very smoothly by setting the proper angle of the conical portion as described above. The rest of the surfacing material is pressed onto the board by the flat retaining surface 8 of the head 2 when the set screw is fully tightened until the head 2 is flush with the surface of the board, never from the head of the screw. It does not stick out.

3 and 4 show an embodiment of another structure of the tip of the set screw. In this example, a cone 3B is formed at the tip of the set screw, and a blade 3C is formed in the cone. The half-cut portion 3D is formed. Yet another embodiment is shown in FIGS. 5 and 6, in which a conical part 3B is formed at the tip of the set screw, the thread continues to this conical part, in which conical part the blade 3b is formed. The notch 3c is formed.
Yet another embodiment is shown in FIGS. 7 and 8. In this example, a conical portion 3B is formed in the cutting portion at the tip of the set screw, and a plurality of blades 3a are formed in the conical portion. In either embodiment, the blade serves to cut into and scrape the surface material of the board. FIG. 9 shows another embodiment of the main threaded portion. In this example, a body portion 9 having no thread and smaller than the diameter of the main thread is formed between the pyramid 3 and the main thread 4. There is. In this case, the gypsum rising by the main screw thread 4 enters the space around the body 9 and the rise of the surface material is suppressed.

[0012]

Since the set screw according to the present invention is constructed as described above and acts on the board as described above, it is possible to prevent the core of the board from rising while the set screw is screwed into the board. The swell around the screw on the board surface,
There is an advantage that it is possible to prevent the inconvenience of fluffing the surface material.

[Brief description of drawings]

FIG. 1 is a side view of a set screw according to the present invention.

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a partial perspective view showing another configuration of the tip portion of the set screw according to the present invention.

FIG. 4 is a side view of a tip portion of the set screw shown in FIG.

FIG. 5 is a partial perspective view showing still another configuration of the tip portion of the set screw according to the present invention.

FIG. 6 is a front view of a tip portion of the set screw shown in FIG.

FIG. 7 is a side view showing still another configuration of the set screw according to the present invention.

FIG. 8 is a sectional view taken along line VIII-VIII in FIG. 7;

FIG. 9 is a side view showing still another configuration of the set screw according to the present invention.

[Description of sign]

 1 Part with screw thread 2 Head 3 Cutting part 4 Main screw thread 5 Double thread screw 6 Conical portion 7 Blade 8 Annular pressing surface 9 Body

Claims (9)

[Claims] 1. A set screw having a threaded portion and a head, wherein a cutting portion which cuts into and scrapes the surface material of the board is formed at the tip of the threaded portion, and the lower portion of the head is screwed. A construction characterized by a conical shape facing the mountain portion and forming a plurality of blades on this conical portion, and forming a flat annular pressing surface on the head between the conical portion and the periphery of the head Screws for board. 2. The set screw for a construction board according to claim 1, wherein the cutting portion at the tip of the set screw has a pyramidal shape, and is cut into the surface material of the board and scraped off. 3. The cutting portion at the tip of the set screw has a conical shape, and the conical portion is formed with a blade configured to cut into and scrape the surface material of the board. Set screw for building board. 4. The screw thread continues to the tip of the set screw, and the tip portion and / or the main screw threaded portion has a notch portion which constitutes a blade for cutting into and scraping the board surface material. The set screw for a building board according to claim 1, which is formed. 5. The set screw for a building board according to claim 4, wherein the notch is notched slightly apart from the tip. 6. The threaded portion is formed by a main thread formed from the cutting portion or the tip thereof and a pitch of the main thread formed between the end of the main thread and the conical portion below the head. 6. The set screw for a building board according to claim 1, wherein the set screw comprises a small auxiliary screw thread. 7. The set screw for a building board according to claim 6, wherein the auxiliary thread is a double thread. 8. A body without a thread having a diameter smaller than the diameter of the main thread is provided between the end of the main thread formed from the cutting portion or the tip thereof and the conical portion below the head. Item 1. A set screw for a construction board according to any one of items 1 to 5. 9. The set screw for a building board according to claim 1, wherein the main screw thread is a double thread.