US4725171A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill for aramid composites
Assignee: Individual
•
Filing: 1984-03-02
•
Granted: 1988-02-16
•
Expires: 2004-03-02
Abstract
Abstract A rotary carbide drill for drilling clean holes in aramid fiber composites is made from a cylindrical rod having a planar elliptical end surface. The drill has a longitudinally extending arcuate flute that becomes shallower as it progresses away from the end surface. The arcuate flute is generated with a diamond wheel or disc having a periphery with a semi-cylindrical cross-section in a manner so that each of two radial segments alternate as the lead cutting surfaces, providing essentially equal wear on the segments so that frequent dressing of the wheel is eliminated.
Inventors
- 👤 Robert P. DeTorre
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 22:58
CPC Classifications
B; B23; B23B; B23B51/00; B23B2226/00; B23B2226/27; B23B2251/00; B23B2251/14; Y; Y10; Y10S; Y10S408/00; Y10S408/704; Y10T; Y10T407/00; Y10T407/19; Y10T407/1946; Y10T407/1948; Y10T408/00; Y10T408/89; Y10T408/901
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
92 words
A rotatable carbide drill, suitable for generating holes in a composite material of an organic resin binder and aramid fibers, comprising: (a) a generally cylindrical rod having an axis of rotation and an outer cylindrical surface, (b) an inclined planar end surface defining an ellipse, said planar surface defining an acute angle with said rod axis, and (c) an axially inclined arcuate shaped flute intersecting the outer surface of the cylindrical rod to form first and second cutting edges and intersecting said planar end surface to form at least one cutting point.
Claim 2
Dependent Claim
92 words
A rotatable carbide drill, suitable for generating holes in a composite material of an organic resin binder and aramid fibers, comprising: (a) a generally cylindrical rod having an axis of rotation and an outer cylindrical surface, (b) an inclined planar end surface defining an ellipse, said planar surface defining an acute angle with said rod axis, and (c) an axially inclined arcuate shaped flute intersecting the outer surface of the cylindrical rod to form first and second cutting edges and intersecting said planar end surface to form at least one cutting point.
Claim 3
Dependent Claim
16 words
The drill of claim 1 wherein said acute angle is from about 15° to about 45°.
Claim 4
Dependent Claim
32 words
The drill of claim 2 wherein the cylindrical rod has a cylindrical surface with a first radius and said arcuate flute has a radius essentially equal to one-half of said first radius.
Claim 5
Dependent Claim
56 words
The drill of claim 2 wherein the ellipse of said planar end surface has a major axis and minor axis and said one cutting point is located substantially at the intersection of said major axis and the longest line of the cylindrical surface, so that said one cutting point can function as the lead cutting point.
Claim 6
Dependent Claim
35 words
The drill of claim 4 wherein said first and second cutting edges intersect said planar end surface to form said lead cutting point and a second trailing cutting point, longitudinally spaced from said lead point.
Claim 7
Dependent Claim
17 words
The drill of claim 5 wherein said trailing cutting point leads the minor axis of said ellipse.
Claim 8
Dependent Claim
32 words
The drill of claim 6 wherein said arcuate flute becomes progressively and uniformly shallower as it proceeds from the lead cutting point to its terminus in the cylindrical surface of the rod.
Claim 9
Dependent Claim
74 words
A rotatable carbide drill, suitable for generating holes in materials containing aramid fibers, comprising: (a) a rod having an axis and an outer cylindrical surface, (b) a planar elliptical end surface having major and minor axes, (c) an arcuate flute, intercepting said elliptical end surface within one leading quadrant thereof and having a semi-cylindrical section at the intercept, the arcuate flute growing shallower as it progresses longitudinally along said rod, away from said intercept.
Claim 10
Dependent Claim
74 words
A rotatable carbide drill, suitable for generating holes in materials containing aramid fibers, comprising: (a) a rod having an axis and an outer cylindrical surface, (b) a planar elliptical end surface having major and minor axes, (c) an arcuate flute, intercepting said elliptical end surface within one leading quadrant thereof and having a semi-cylindrical section at the intercept, the arcuate flute growing shallower as it progresses longitudinally along said rod, away from said intercept.
Claim 11
Dependent Claim
19 words
The drill of claim 8 wherein the axis of the arcuate flute is angularly skewed from the rod axis.
Claim 12
Dependent Claim
18 words
The drill of claim 9 wherein said axes form an acute angle from about 8° to about 12°.
References Cited (Backward Citations)
US1476019A
Cited
US1781863A
Cited
US2640379A
Cited
US4034452A
Cited
US4285620A
Cited
US4395169A
Cited
US4338050A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-02-15 | 1991-08-17 | 1992-02-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-02-15 | 1995-08-17 | 1996-02-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-02-15 | 1999-08-17 | 2000-02-16 | $7700.00 | Window Closed / Lapsed |