Self-tapping screws with chip removal function

Abstract

A chip-removing self-tapping screw is disclosed to solve the problem of poor chip removal in self-tapping screws. It comprises: a shaft having an axial centerline; a first end of the shaft having a cap; a second end of the shaft having a tapping portion; a threaded portion extending from the tapping portion toward the cap having a terminating end; a gap between the terminating end and the cap forming a chip-removing section; and at least one enlarged portion located in the chip-removing section. The enlarged portion includes a wing and two guide ribs, the wing and the two guide ribs protruding from the outer surface of the shaft. The wing has a beveled cut surface, and the two guide ribs protrude from two sides of the wing and are non-parallel to the outer surface of the shaft, forming an open end at the second end of the two guide ribs. This design enables smooth chip removal from the self-tapping screw.

Claims

1. A self-tapping screw with chip removal capability, comprising: A rod body has an axial centerline. A first end of the rod body has a cap with a drive groove. A second end of the rod body has a tapping portion. A threaded portion protrudes from and surrounds the outer surface of the rod body. The threaded portion extends from the tapping portion toward the cap with a terminating end. A gap exists between the terminating end and the cap to form a chip removal section. At least one enlarged portion is located in the chip removal section. The enlarged portion includes a wing and two guide ribs. The wing and the two guide ribs protrude from the outer surface of the rod body. The wing has a predetermined thickness and is connected to the rod body from a bottom. The wing has a beveled cutting surface facing the tapping portion of the rod body. The beveled cutting surface forms an angle with the axial centerline. The two guide ribs protrude from two sides of the wing and are non-parallel to the outer surface of the rod body, forming an opening at their second ends.

2. As in request item 1, a self-tapping screw with chip removal capability, wherein, The chip removal section has at least one groove.

3. As in request item 2, a self-tapping screw with chip removal capability, wherein, There are at least two grooves, and the two grooves are symmetrically located in the chip removal section.

4. Self-tapping screws with chip removal function as requested in item 2 or 3, wherein, The bottom of the wing is located in at least one groove.

5. As in request item 1, a self-tapping screw with chip removal capability, wherein, The beveled cutting surface forms an angle with the axial centerline of the rod.

6. Self-tapping screws with chip removal as described in request item 5, wherein, The included angle is between 16° and 20°.

7. As in request item 6, a self-tapping screw with chip removal capability, wherein, The included angle is between 18° and 19°.

8. Self-tapping screws with chip removal as described in request item 1, wherein, The wing also has a back-cutting surface, which is connected to the oblique cutting surface and faces the cap.

9. As in request item 8, a self-tapping screw with chip removal capability, wherein, The first end of the two guide ribs is connected to the back cutting surface.

10. A self-tapping screw with chip removal as described in claim 1, wherein, The second end of the two guide ribs is connected to the oblique cutting surface.

11. As in claim 1, a self-tapping screw with chip removal capability, wherein, There are at least two enlarged holes, and the two enlarged holes are symmetrically located in the chip removal section.

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