Explosive assembly systems including a linear shaped charge end prime cap apparatus and related methods

Abstract

Generally, embodiments of the invention can include a linear shaped charge (LSC) end cap coupling structure adapted for holding an initiator structure adapted to initiate a booster explosive material, the booster explosive material, and the LSC in abutting contact with each other. One embodiment includes a rubber body formed with cavities adapted to receive the LSC, booster, and initiator structure (e.g., detonation cord). One internal cavity can be formed with a plurality of flexible protrusions or fins which are oriented towards a center axis of the preferred embodiment of three cavities configured to impart an interference fit with the initiator structure. Methods related to the invention are also provided.

Claims

1. A coupling structure comprising: a body formed from an elastomeric material comprising a shaft end section and an opposing neck protrusion section, wherein said shaft end section and neck protrusion section are formed respectively with a first and second aperture that open into a first and second cavity section within said body, said first and second cavity sections open into each other, wherein said first cavity section is formed with a first interior cavity wall having a first distance between opposing sides of said first cavity section, wherein said second cavity section is formed with a second interior cavity wall having a second distance between opposing sides of said second cavity section, wherein the first distance is larger than the second distance; wherein said shaft end section is formed with a flexible interference fit adapted to receive and retain a linear shaped charge (LSC) up to a first force; wherein said second cavity section within said neck protrusion section is formed comprising a plurality of spaced apart protrusions or fins that extend a first distance away from said second cavity section wall towards a common center axis, wherein said plurality of spaced apart protrusions or fins are adapted or formed to displace, securely grip, and retain a initiator structure inserted into said second cavity through said neck protrusion up to a second force; wherein said neck protrusion section comprises a plurality of external stiffening sections adapted to increase structural rigidity of said neck protrusion formed on an exterior wall of said neck protrusion section and coupled to a portion of said shaft end section that extends away from said neck protrusion section.

2. A coupling structure as in claim 1, wherein said plurality of spaced apart protrusions or fins extend into said second cavity less than half of a distance defined by a radius from said common center axis of said second cavity to said second interior cavity section wall.

3. A coupling structure as in claim 1, wherein said second aperture into said second cavity is formed having an angled bevel surrounding said second aperture wherein said angled bevel is formed to facilitate insertion of said initiator structure.

4. A coupling structure as in claim 1, wherein said first cavity is adapted to receive an explosive sheet booster and hold said explosive sheet booster in contact with said LSC upon insertion of said LSC into said shaft end section, said coupling structure further formed to hold said initiator structure in contact with a user installed booster on an opposing side of said explosive sheet booster from said LSC.

5. A coupling structure as in claim 4, further comprising said LSC, said explosive sheet booster, said user installed booster, and said initiator structure.

6. An explosive assembly including a coupling structure comprising: a body formed from an elastomeric material comprising a shaft end section and an opposing neck protrusion section; wherein said shaft end section and opposing neck protrusion section are formed respectively with a first and second aperture that open into a first and second cavity section within said body, said first and second cavity sections open into each other, wherein said first cavity section is formed by a first interior cavity wall having a first distance between opposing sides of said first cavity section, wherein said second cavity section is formed by a second interior cavity wall having a second distance between opposing sides of said second cavity section, wherein the first distance is larger than the second distance; a linear shaped charge (LSC); wherein said shaft end section is formed with a flexible interference fit adapted to receive and retain the linear shaped charge up to a first force; wherein said second cavity section within said opposing neck protrusion section is formed comprising a plurality of spaced apart protrusions or fins that extend a third distance away from said second interior cavity wall, wherein said plurality of spaced apart protrusions or fins are adapted or formed to displace, securely grip; and retain a initiator structure inserted into said second cavity section through said opposing neck protrusion up to a second force; wherein said opposing neck protrusion section comprises a plurality of external stiffening sections adapted to increase structural rigidity of said opposing neck protrusion formed on an exterior wall of said opposing neck protrusion section and coupled to a portion of said shaft end section that extends away from said opposing neck protrusion section.

7. An explosive assembly as in claim 6, wherein said plurality of spaced apart protrusions or fins extend into said second cavity section less than half of a distance defined by a radius from a common center axis of said second cavity section to said second interior cavity section wall.

8. An explosive assembly as in claim 6, wherein said second aperture into said second cavity section is formed having an angled bevel surrounding said second aperture wherein said angled bevel is formed to facilitate insertion of said initiator structure.

9. An explosive assembly as in claim 6, wherein said first cavity section is adapted to receive a sheet booster explosive material and hold said sheet booster explosive material in contact with said LSC upon insertion of said LSC into said shaft end section, said explosive assembly further formed to hold said initiator structure in contact with a booster explosive material on an opposing side of said sheet booster explosive material from said LSC.

10. An explosive assembly as in claim 9, further comprising said sheet booster explosive material, said booster explosive material, and said initiator structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The detailed description of the drawings particularly refers to the accompanying figures in which:

(2) FIG. 1 shows an exemplary side view of a V-Prime structure and LSC inserted into the V-Prime structure;

(3) FIG. 2 shows an outer view of the exemplary V-Prime structure;

(4) FIG. 3 shows a first internal cross sectional view of the exemplary V-Prime and LSC;

(5) FIG. 4 shows a second internal cross sectional view of the exemplary V-Prime structure;

(6) FIG. 5 shows a third cross sectional view of the exemplary V-Prime structure;

(7) FIG. 6 shows a fourth internal cross sectional view of the exemplary V-Prime structure;

(8) FIG. 7 shows an exemplary cross sectional view of U-Prime fins in a neck protrusion section of the V-Prime structure;

(9) FIG. 8a shows an exemplary method in accordance with one embodiment of the invention; and

(10) FIG. 8b shows a continuation of the FIG. 8a method.

DETAILED DESCRIPTION OF THE DRAWINGS

(11) The embodiments of the invention described herein are not intended to be exhaustive or to limit the invention to precise forms disclosed. Rather, the embodiments selected for description have been chosen to enable one skilled in the art to practice the invention.

(12) FIG. 1 shows an exemplary side view of a V-Prime 1 and LSC 3. An exemplary V-Prime 1 can be made of molded elastomeric material, such as rubber, fitted to house an appropriate LSC 3 material on one end, and a detonator cord (detcord) 5 on another end with a booster explosive material (not shown) inserted between the two within the V-Prime 1. When in use, a user could insert detcord 5 into a detcord insertion end 21 of exemplary V-Prime 1 and initiate the LSC and booster explosive with an appropriate detonator from a safe distance. In one exemplary embodiment of the V-Prime 1, explosive sheet booster and user-installed booster explosives in the V-Prime 1 can be of a same hazard class as the LSC 3 so booster loaded V-Primes 1 can be transported on the LSC 3 to a point of use. One exemplary LSC 3 material can be formed with a minimum of 8-10 inches or up to 6 feet in length.

(13) FIG. 2 shows an outer view of the exemplary V-Prime 1. The V-Prime 1 can be a rubber structure that primes an end of the LSC charge and allows for safer, easier, more efficient insertion of the detcord 5 (not shown) into a neck protrusion 7 of the V-Prime 1. Stiffeners 11 formed onto external portions of the V-Prime 1 support the neck protrusion area 7, of the V-Prime 1 to increase rigidity of the neck protrusion 7 with respect to remaining portions of the V-Prime 1. An LSC insertion shaft 9 of the V-Prime 1 be formed to receive and retain the LSC 3 with a semi-rigid or flexible gripping interference fit. In one exemplary embodiment of the V-Prime 1, a V-Prime 1 can be placed over an end of the LSC 3 with or without any booster material to serve as a coupling structure, thus improving safe handling of the charge.

(14) FIG. 3 shows a first internal cross sectional view of exemplary V-Prime 1 and LSC 3. An internal cavity 17, or third cavity, of the V-Prime 1 can be sized to contain user installed booster explosive 23, e.g., a partial MK 140 flexible booster explosive. In particular, a neck protrusion 7 of this exemplary V-Prime 1 can be formed with the internal cavity 17 for the user installed booster explosive 23. Stiffeners 11 buttress the neck protrusion 7 to the shaft 9, and increase rigidity and structural integrity for the neck protrusion 7. Shaft 9 of V-Prime 1 within a first cavity 31 internal to the LSC insertion shaft 9 insertably receives and grips the LSC 3, and can have an internal cavity for a thin layer, e.g., on the order of 1/16 of an inch of explosive sheet booster 19. Explosive sheet booster 19 can be positioned vertically to a center insertion axis of the V-Prime 1 internal cavity 17 and in direct contact with an exposed end of the LSC 3. The user installed booster explosive 23 can be positioned adjacent to and in direct contact with both the explosive sheet booster 19 and the detcord 5 on opposing sides of the user installed booster explosive 23. As with the explosive sheet booster 19, user installed booster explosive 23 can be cut and placed inside the V-Prime 1 by the user before slipping the V-Prime 1 over the exposed end of the LSC 3 into the first cavity 31. The neck protrusion 7 of the V-Prime 1 has an open end 25 extending along said first axis for detcord 5 insertion. This exemplary open end 25 can be circumferentially lined with a plurality of flexible fins 15 to accept and secure blasting caps, detonators and detonating cord. Bevel 13 can be sloped to an angle, such as an exemplary 158 degrees, to facilitate in the insertion of the detcord 5 into the neck protrusion 7. The angle of the bevel 13 can be formed by the shape of the open end 25 and the plurality of flexible fins 15. Internal cavity 17 can open into a second cavity 33 which is internal to the neck protrusion 7.

(15) FIG. 4 shows a second internal cross sectional view of the exemplary V-Prime 1. Shaft 9 of the V-Prime 1 can be a hexagonal shape that can be fitted to contain a V-shaped LSC 3 (not shown). Shaft 9 of V-Prime 1 is designed to contain and grip the LSC 3, and internal cavity 17 can hold explosive sheet booster 19. Shaft 9 of V-Prime 1 securely grips the end of LSC 3 with a compression fit. Shaft 9 cuts explosive sheet booster 19 to the shape of shaft 9. This built-in cutting feature of shaft 9 cuts explosive sheet booster 19 to the exact shape required to fit into internal cavity 17 of V-Prime 1, up to the internal shoulder (not shown) of internal cavity 17. Neck protrusion 7 of V-Prime 1 can be sized to contain user installed booster explosive 23. The user installed booster explosive 23, would be positioned vertically to the axis in neck protrusion 7 of V-Prime 1 and in direct contact with explosive sheet booster 19 which directly contacts the end of LSC 3 (not shown). Detcord 5 can be securely gripped by the plurality of flexible fins 15.

(16) FIG. 5 shows a third cross sectional view of exemplary V-Prime 1. V-Prime 1 can have one or more external supporting stiffeners 11 around neck protrusion 7. Stiffeners 11 circumferentially support and reinforce neck protrusion 7.

(17) FIG. 6 shows a fourth internal cross sectional view of exemplary V-Prime 1. Here, the rubber material of shaft 9 and neck protrusion 7 is represented by the lined outer area of the figure. Explosive sheet booster 19 (not shown) can be in direct contact with user installed booster explosive 23. The plurality of flexible fins 15 grab onto detcord 5 (not shown). Bevel 13 facilitates the insertion of detcord 5. Explosive sheet booster 19 (not shown) can be positioned nearly all the way to internal shoulder 27 of V-Prime 1. The shaft 9 can have a first aperture 35 on one end of the V-Prime 1, and a second aperture 37 on an opposing end of the V-Prime 1 opening into the neck protrusion 7.

(18) FIG. 7 shows an exemplary cross sectional view of a plurality of flexible fins 15 in neck protrusion 7 of the V-Prime 1. Detcord 5 is inserted in a circular tube shaped area created by the plurality of flexible fins 15 in neck protrusion 7. A supporting stiffener 11 is shown flanking neck protrusion 7. In one exemplary embodiment, V-Prime 1 incorporates the plurality of flexible fins 15 in the design of a direct insert universal detonator well (U-Prime) fins in neck protrusion 7. U-Prime fins provide a secure insertion of various diameter detonator cords without the need for a specialized adapter.

(19) Referring to FIG. 8a, a method is provided that includes: Step 101: Providing an explosive assembly structure with an initiator structure adapted to initiate a booster explosive material where linear shaped charge and a body of elastomeric material can be formed with a first body portion and a second body portion where the second body portion extends away from the first body portion, and can be formed with stiffening structures coupled to a side of the first body portion and coupled with the second body portion's external surface. Step 103: Having a first, second, and third cavity of the body where the first cavity can be formed to insertably receive said linear shaped charge with a flexible interference fit. Step 105: Forming the second cavity to insertably receive the booster explosive material. Step 107: Forming the third cavity to insertably receive a first explosive structure. Step 109: Forming the first, second and third cavities to retain the initiator structure in contact with the booster explosive material and retain the linear shaped charge with an opposing side of the booster explosive material.

(20) Referring to FIG. 8b, FIG. 8a continues at Step 111: Forming the first cavity smaller than the second cavity, and the second cavity smaller than the third cavity. Step 113: Forming the third cavity with a plurality of flexible protrusions configured to impart an interference fit with the initiator structure. Step 115: Forming the first, second, and third cavities respectively with a common center axis, where one side of each of the first and third cavities respectively define a first and second external opening in the body on opposing sides of the body. Step 117: Forming the third cavity's external opening with a beveled or internally tapering edge surrounding a wall section of the third cavity where the plurality of flexible protrusions extend from. Step 119: Positioning said explosive assembly in proximity to a target; and Step 121: Detonating said explosive assembly by actuating a detonation cord.

(21) Methods of use can also include providing an exemplary V-Prime 1 such as described above, including detonation cord 5, booster sheet explosive 19, and LSC 3 inserted into the V-Prime 1 in physical contact. Next, the V-Prime 1 assembly with detonator cord 5, booster sheet explosive 19, and LSC 3 are positioned relative to a target surface. Next, the detonation cord 5 is actuated so as to detonate the booster sheet explosive 19 and LSC 3. Methods of manufacturing can include forming the V-Prime 1 with internal cavities dimensioned to receive and retain the LSC 3, booster sheet explosive 19, and detonation cord 5 coupling the LSC 3, booster sheet explosive 19 as described herein.

(22) Although the invention has been described in detail with reference to certain preferred embodiments, variations and modifications exist within the spirit and scope of the invention as described and defined in the following claims.