Precision drill bits
AssigneeCredo Technology Corporation
InventorCarl W. Risen, Jr.
Life of this patent
Estimating the term…
Abstract
A precision drill bit comprises an elongated body having a stepped centering tip at one end and an engagement shank at the opposite end. A first portion of the bit adjacent the tip has an outer diameter that is less than the outer diameter of a second portion of the bit. At least one cutting flute extends along the length of the bit and exhibits a helix angle of about 38° at the tip. The helix angle decreases to an angle of about 15° at the end of the flute run-out. The helix angle changes progressively and substantially linearly over a number of segments along the length of the drill bit.
Claims32
A drill bit comprising:
- an elongated body having a tip at one end and an engagement shank at the opposite end, a first portion of said body adjacent said tip having a first diameter and a second portion between said first portion and said engagement shank having a second diameter greater than said first diameter;
- said elongated body defining at least one flute in at least said second portion, said flute formed at a helix angle relative to the longitudinal axis of said elongated body, the helix angle decreasing from said tip to said engagement shank,
- wherein the helix angle starts at about 38° adjacent said tip and the helix angle at said engagement shank is about 15°,
- wherein the helix angle decreases from about 38° adjacent said tip to about 35° at a first distance from said tip,
- wherein the helix angle decreases from about 35° at said first distance to about 17° at a second distance from said tip,
- wherein the helix angle decreases from about 17° at said second distance to about 15° at a third distance from said tip,
- wherein said third distance is at least 3.5 inches,
- wherein the helix angle decreases substantially linearly over said third distance,
- wherein the helix angle decreases substantially linearly over said first distance at a first slope, the helix angle decreases substantially linearly over said second distance at a second slope that is greater than said first slope, and the helix angle decreases substantially linearly over said third distance at a third slope that is less than said second slope.
A drill bit comprising:
- an elongated body having a tip at one end and an engagement shank at the opposite end, said elongated body defining at least one flute, said flute formed at a helix angle relative to the longitudinal axis of said elongated body, the helix angle decreasing substantially linearly at a first slope over a first distance from said tip, substantially linearly at a second slope over a second distance from said tip greater than said first distance, and substantially linearly at a third slope over a third distance from said tip greater than said second distance.
A drill bit comprising an elongated body having a tip at one end and an engagement shank at the opposite end,
- wherein said elongated body defines at least one flute, said flute being formed at a helix angle relative to a longitudinal axis of said elongated body, and
- wherein the helix angle decreases (i) substantially linearly over a first segment of said elongate body at a first slope, (ii) substantially linearly over a second segment of said elongate body at a second slope that is greater than said first slope, and (iii) substantially linearly over a third segment of said elongate body at a third slope that is less than said second slope.
A drill bit comprising an elongated body having a tip at one end and an engagement shank at the opposite end,
- wherein said elongated body defines at least one flute, said flute being formed at a helix angle relative to a longitudinal axis of said elongated body,
- wherein the helix angle decreases (i) substantially linearly over a first segment of said elongate body at a first slope, (ii) substantially linearly over a second segment of said elongate body at a second slope that is greater than said first slope, and (iii) substantially linearly over a third segment of said elongate body at a third slope that is less than said second slope,
- wherein the helix angle decreases from about 38° at one end of said first segment to about 35° at another end of said first segment,
- wherein the helix angle decreases from about 35° at one end of said second segment to about 17° at another end of said second segment, and
- wherein the helix angle decreases from about 17° at one end of said third segment to about 15° at another end of said third segment.
Dependencies are inferred from the claim text.