Method of machining V-notch grooves for controlled fragmentation of warheads
An improved method of machines grooves forming Pearson notches in a pattern on hollow shell casings for munitions for at least one of increased functionality and/or performance. Rather than running a broach through a hollow casing, a CNC lathe with a multi-axis tool with cutting implement can precisely locate and form grooves along either an interior or an exterior surface of a hollow shell casing.
1. A method of manufacturing a fragmentation control pattern in armament shells comprising the steps of:
(a) rotating a hollow shell casing about an axis, while simultaneously
(b) linearly moving a rotating cutting tool along a surface of the hollow shell casing thereby cutting at least first and second walls to provide a first groove as a portion of a pattern of Pearson Notches about the surface of the hollow shell casing; and whereby
(c) upon detonation of a warhead within the hollow shell casing, at least 90% fragmentation is achieved.
2. The method of manufacturing of claim 1 wherein surface is an interior surface of the hollow shell casing.
3. The method of manufacturing of claim 1 wherein the surface is an exterior surface of a hollow shell casing.
4. The method of manufacturing of claim 1 wherein the angle between the first and second walls changes at least 10 degrees over a length of the first groove.
5. The method of manufacturing of claim 1 wherein a depth of the first groove changes over a length of the first groove.
6. The method of manufacturing of claim 5 wherein the first groove terminates internal to a bore of the hollow shell casing.
7. The method of manufacturing of claim 1 further comprising a second groove proceeding along a similar direction of rotation about the hollow shell casing with the first groove, and at least portions of the first and second groove are not parallel.
8. The method of manufacturing of claim 1 wherein the pattern of Pearson notches changes along a length of the hollow shell casing.
9. A method of manufacturing a fragmentation control pattern in armament shells comprising the steps of:
(a) rotating a hollow shell casing about an axis with a CNC lathe while simultaneously
(b) linearly moving a rotating cutting tool along a surface of the hollow shell casing thereby cutting at least first and second planes to provide a pattern of Pearson Notches about the surface of the hollow shell casing; wherein
(c) a first length of a first groove forming a Pearson notch on a surface of the hollow shell casing has a first location with a first angle between first and second planes and a second location of the groove has a second angle between the first and second planes, wherein the first angle is at least five degrees larger than the second angle.
10. The method of manufacturing of claim 9 wherein the first angle and the second angle differ by at least 10 degrees.
11. The method of manufacturing of claim 9 wherein the first groove terminates at the surface along the first length.
12. The method of manufacturing of claim 9 wherein a pattern of groves having the first groove changes along a length of the hollow shell casing.
13. The method of manufacturing of claim 9 further comprising a second groove proceeding along a similar direction of rotation about the hollow shell casing with the first groove, and at least portions of the first and second groove are not parallel.
14. The method of manufacturing of claim 9 wherein a depth of the first groove changes over the first length of the first groove.
15. The method of manufacturing of claim 9 wherein upon detonation of a warhead within the hollow shell casing, at least 90% fragmentation is achieved.
16. A method of manufacturing a fragmentation control pattern in armament shells comprising the steps of:
(a) rotating a hollow shell casing about an axis with a CNC lathe while simultaneously
(b) linearly moving a rotating cutting tool along a surface of the hollow shell casing thereby cutting at least first and second planes to provide a pattern of Pearson Notches about the surface of the hollow shell casing; wherein
(c) a first length of a first groove forming a Pearson notch on a surface of the hollow shell casing has a first location with a first depth and a second location with a second depth at least 10% longer than the first depth.
17. The method of manufacturing of claim 16 wherein upon detonation of a warhead within the hollow shell casing, at least 90% fragmentation is achieved.
18. The method of manufacturing of claim 16 wherein the first groove has a first location having a first angle between first and second planes and a second location of the first groove has a second angle between the first and second planes, wherein the first angle is at least five degrees larger than the second angle.
19. The method of manufacturing of claim 16 further comprising a second groove proceeding along a similar direction of rotation about the hollow shell casing with the first groove, and at least portions of the first and second groove are not parallel.
20. The method of manufacturing of claim 1 wherein the pattern of Pearson notches changes along a length of the hollow shell casing.