Self-drilling screw
OwnerYing-Chin Chaoinventor
Life of this patent
Estimating the term…
Abstract
A self-drilling screw includes a head, a thread shank and a pilot end. The thread shank includes a shank body and a thread portion. The thread shank is cut with cutting grooves extending axially from the shank body and formed by cutting through the thread portion into the shank body. The pilot end is gradually tapered, and defines two chip-clearing flutes formed by cutting and extending over the thread portion and the pilot end and by cutting and extending through a portion of the pilot end. Each chip-clearing flute is in communication with the corresponding cutting groove. Each cutting groove partially overlaps the corresponding chip-clearing flute at the normal vector projection to enhance chip removal.
Claims25
A self-drilling screw, comprising:
- a head;
- a thread shank including a shank body and a thread portion which projects from an outer peripheral surface of said shank body and extends spirally along said shank body, said thread shank being cut with a plurality of cutting grooves which extend axially from said shank body and are formed by cutting through said thread portion into said shank body;
- and
- a pilot end extending axially from said shank body away from said head and gradually tapered, said pilot end defining two chip-clearing flutes which face in different directions, each of said chip-clearing flutes being defined by a curve surface, an inclined surface, a cutting edge surface and a bottom surface, said chip-clearing flutes being formed by cutting and extending over said thread portion and said pilot end and by cutting and extending through a portion of said pilot end, each of said chip-clearing flutes extending axially along said pilot end and being in communication with a respective one of said cutting grooves, wherein a normal vector projection of each of said cutting grooves on an imaginary plane partially overlaps a normal vector projection of a corresponding one of said chip-clearing flutes on the imaginary plane.
Dependencies are inferred from the claim text.