Screw for fastening wooden materials
AssigneeSheh Fung Screws Co., Ltd.
InventorChun-Yen Chen
Life of this patent
Estimating the term…
Abstract
A screw includes a shank portion including a tapered bottom section having a tip, a head on top of the shank portion, and first and second helical threads. The first helical thread extends helically around the shank portion in a first direction between the tip and the head, and has a first end distal from the head, and a second end opposite to the first end. The second helical thread extends helically around the shank portion in a second direction between the first helical thread and the tip, and has a third end proximate to the second end of the first helical thread. The first and second directions are opposite to each other. A non-helical ridge extends around the shank portion between the first and second helical threads.
Claims5
A screw comprising:
- a shank portion including a tapered bottom section having a tip;
- a head on top of said shank portion;
- a first helical thread extending helically around said shank portion in a first direction between said tip and said head, and having a first end distal from said head, and a second end opposite to said first end;
- a second helical thread extending helically around said shank portion in a second direction between said first helical thread and said tip, and having a third end proximate to said first end of said first helical thread, said first and second directions being opposite to each other;
- and
- a non-helical first ridge extending around said shank portion between said first and second helical threads and having a major diameter substantially identical to that of each of said first and second helical threads, said non-helical first ridge including a single non-helical crest extending around said shank portion, and two inclined faces tapering from said single non-helical crest in opposite directions;
- wherein said inclined faces of said first ridge are respectively in contact with said first end of said first helical thread and said third end of said second helical thread.
Dependencies are inferred from the claim text.