Jan. 24th: Patent Description - Andrew McBride: Difference between revisions
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Patent number: 4697969 | Patent number: 4697969 | ||
Filing date: Sep 6, 1985 | Filing date: Sep 6, 1985 | ||
Issue date: Oct 6, 1987 | Issue date: Oct 6, 1987 | ||
This patent claims an improved wood screw with either a flat head, hex head or phillips head, and having two flutes of semi-circular cross-section, the first beginning at the tip of the screw and ending near the head of the screw, and the second beginning at the tip of the screw and continuing a length of about three screw heads from the tip. Both flutes have a diameter about a third of the screw's root diameter, and the tangent lines to each flute axis form an angle of 30º with the screw's axis. | This patent claims an improved wood screw with either a flat head, hex head or phillips head, and having two flutes of semi-circular cross-section, the first beginning at the tip of the screw and ending near the head of the screw, and the second beginning at the tip of the screw and continuing a length of about three screw heads from the tip. Both flutes have a diameter about a third of the screw's root diameter, and the tangent lines to each flute axis form an angle of 30º with the screw's axis. | ||
Revision as of 01:07, 26 January 2011
Wood Screw
Patent number: 4697969
Filing date: Sep 6, 1985
Issue date: Oct 6, 1987
This patent claims an improved wood screw with either a flat head, hex head or phillips head, and having two flutes of semi-circular cross-section, the first beginning at the tip of the screw and ending near the head of the screw, and the second beginning at the tip of the screw and continuing a length of about three screw heads from the tip. Both flutes have a diameter about a third of the screw's root diameter, and the tangent lines to each flute axis form an angle of 30º with the screw's axis.
