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US 8,087,856 B2Granted
Double helix thread cutting tap
OwnerGary J. Reedinventor
Life of this patent
Estimating the term…
Abstract
The invention includes a double helix thread cutting tap with both right-handed and left-handed helical chip removal flutes. The double helix thread cutting tap places a positive rake angle on all sets of thread cutting teeth for optimum performance and minimal cutting pressure.
Claims25
A tap, comprising:
- an upper driving end;
- a shank below said upper driving end;
- a threaded portion having a length below said shank and terminating in a bottom end, said threaded portion including cutting teeth extending along said length of said threaded portion;
- a plurality of helical flutes extending from said bottom end around a circumference of said threaded portion into said shank, wherein said helical flutes have a twist in a first direction;
- and
- a partial helical flute contained in at least one of said plurality of helical flutes adjacent said bottom end, wherein said partial helical flute has a twist in a second direction opposite said first direction.
3 more elements
A tap, comprising:
- an elongated body having upper end and a bottom end;
- said elongated body extending along a longitudinal axis between said upper end and said bottom end;
- a threaded portion having a length above said bottom end of said elongated body, said threaded portion including cutting teeth extending along said length of said threaded portion;
- a plurality of helical flutes each formed in an outer periphery of the elongated body at a location interrupting said threaded portion and each extending about the longitudinal axis in a twist in a first direction;
- and
- a partial helical flute contained in at least one of said plurality of helical flutes at a location adjacent said bottom end of said elongated body, each said partial helical flute extending about the longitudinal axis in a twist in a second direction opposite said first direction.
3 more elements
A tap, comprising:
- an upper driving end;
- a shank below said upper driving end;
- a threaded portion having a length below said shank and terminating in a bottom end, said threaded portion including cutting teeth extending along said length of said threaded portion;
- at least one first helical flute having a twist in a first direction and extending from said bottom end around a circumference of said threaded portion into said shank;
- at least one second helical flute having a twist in said first direction and extending from said bottom end around a circumference of said threaded portion into said shank;
- and
- a partial helical flute contained in said second helical flute adjacent said bottom end, said partial helical flute having a twist in a second direction opposite said first direction.
4 more elements
Dependencies are inferred from the claim text.