Tapping screw
First Claim
1. A tapping screw comprising a head portion and a shaft portion extending from said head portion, and forming a female screw in a prepared hole formed in an attached member while the tip portion of said shaft portion is screwed into said prepared hole;
- wherein said shaft portion has;
a columnar constant diameter portion extending from said head portion and having a constant diameter;
a reduced diameter portion of a truncated cone shape extending from the tip of said constant diameter portion in the direction opposed to said head portion, and reduced in diameter as it is advanced in the direction opposed to said head portion; and
a spiral screw thread continuously formed over the outer circumferential face of said constant diameter portion and the outer circumferential face of said reduced diameter portion;
plural notch portions are formed in a specific area of said screw thread in the circumferential direction of said shaft portion; and
said notch portion has a notch face, a rising wall and a corner portion.
1 Assignment
0 Petitions
Accused Products
Abstract
The tapping screw has a screw thread having a non-circular shape. Accordingly, when the tapping screw is screwed into the prepared hole formed in the attached member such as a steel plate, etc., the contact area of the screw thread and the circumferential face of the prepared hole of the attached member can be reduced in comparison with the screw thread having a circular outer shape. Accordingly, the screwing torque can be reduced. Further, since the top portion of the screw thread of the square outer shape has a rising shape without being broken, the biting property of the screw thread with respect to the prepared hole formed in the attached member is improved so that a female screw can be precisely threaded on the inner circumferential face of the prepared hole by the screw thread.
75 Citations
11 Claims
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1. A tapping screw comprising a head portion and a shaft portion extending from said head portion, and forming a female screw in a prepared hole formed in an attached member while the tip portion of said shaft portion is screwed into said prepared hole;
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wherein said shaft portion has;
a columnar constant diameter portion extending from said head portion and having a constant diameter;
a reduced diameter portion of a truncated cone shape extending from the tip of said constant diameter portion in the direction opposed to said head portion, and reduced in diameter as it is advanced in the direction opposed to said head portion; and
a spiral screw thread continuously formed over the outer circumferential face of said constant diameter portion and the outer circumferential face of said reduced diameter portion;
plural notch portions are formed in a specific area of said screw thread in the circumferential direction of said shaft portion; and
said notch portion has a notch face, a rising wall and a corner portion. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A tapping screw comprising a head portion and a shaft portion extending from said head portion, and forming a female screw in a prepared hole formed in an attached member while the tip portion of said shaft portion is screwed into said prepared hole;
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wherein said shaft portion has;
a columnar constant diameter portion extending from said head portion and having a constant diameter;
a reduced diameter portion of a truncated cone shape extending from the tip of said constant diameter portion in the direction opposed to said head portion, and reduced in diameter as it is advanced in the direction opposed to said head portion; and
a spiral screw thread continuously formed over the outer circumferential face of said constant diameter portion and the outer circumferential face of said reduced diameter portion; and
the outer shape seen from the axial direction of said screw thread is set to be non-circular in the specific area of said screw thread. - View Dependent Claims (10, 11)
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Specification