Claims
- 1. A low-energy detonating cord adapted for use as a trunkline and/or a downline cord in a non-electric blasting assembly and comprising
- (a) an axial continuous solid core of a deformable bonded detonating explosive composition comprising at least about 55 percent by weight of a cap-sensitive crystalline high explosive compound selected from the group consisting of organic polynitrates and polynitramines admixed with a binding agent, the particles of crystalline high explosive compound in said composition having their maximum dimension in the range of about from 0.1 to 50 microns, and the diameter and the explosive content of said core being such as to provide about from 0.1 to 2 grams of crystalline high explosive compound per meter of length of said cord;
- (b) surrounding said axial explosive core, protective sheathing consisting solely of one or more layers of plastic material, the plastic material being one which is capable of flowing at a temperature not exceeding the melting point of said crystalline high explosive compound by more than about 75.degree. C.; and
- (c) core-reinforcement means outside said core adapted to provide said cord with a tensile strength of at least about 9 kilograms comprising at least one continuous strand of yarn running substantially parallel to said core's longitudinal axis.
- 2. A detonating cord of claim 1 wherein said core-reinforcement means is present in or around said protective sheathing.
- 3. A detonating cord of claim 1 wherein said core-reinforcement means consists essentially of at least one continuous strand of yarn on the periphery of said core and running substantially parallel to said core's longitudinal axis, said sheathing surrounding said core and said strand(s).
- 4. A detonating cord of claim 3 wherein said core-reinforcement means comprises at least four strands of yarn substantially uniformly distributed about and in contact with the periphery of said core, having sufficient tensile strength as to provide said core with a tensile strength of at least about 10 pounds, and said sheathing enclosing said core and said strands.
- 5. A detonating cord of claim 3, wherein said yarn is a multifilament yarn, and the filaments thereof are dispersed around said core.
- 6. A detonating cord of claim 1 wherein said crystalline high explosive compound is selected from the group consisting of pentaerythritol tetranitrate and cyclotrimethylenetrinitramine.
- 7. A detonating cord of claim 6 wherein said explosive composition contains at least about 70 percent by weight of pentaerythritol tetranitrate (PETN), said core contains at least about 0.4 grams of PETN per meter of length, and said sheathing is made of a thermoplastic material.
- 8. A detonating cord of claim 7 wherein said binding agent is plasticized nitrocellulose.
- 9. A detonating cord of claim 7 wherein said thermoplastic material is a polyolefin which is capable of flowing at a temperature below about 200.degree. C.
- 10. A detonating cord of claim 9 wherein said thermoplastic material is polyethylene and said sheathing is about from 0.051 to 0.127 cm thick.
- 11. A detonating cord of claim 7 wherein the thickness of said sheathing is in the range of about from 0.013 to 0.318 cm.
- 12. A detonating cord of claim 1 wherein the diameter of said axial explosive core is up to about 0.152 cm, the overall diameter of the cord is up to about 0.254 cm, and the cord's tensile strength is at least about 32 kilograms.
- 13. A detonating cord of claim 12 adapted to propagate a detonation after having been repeatedly dragged over the edge of a concrete block by a 2.7 kg weight tied to one of its ends.
- 14. A detonating cord of claim 1 adapted to propagate a detonation after having been repeatedly dragged over the edge of a concrete block by a 2.7 kg weight tied to one of its ends.
- 15. A low-energy detonating cord consisting essentially of
- (a) a continuous solid core of a deformable bonded detonating explosive composition comprising at least about 55 percent by weight of a cap-sensitive crystalline high explosive compound selected from the group consisting of organic polynitrates and polynitramines admixed with a binding agent, the particles of crystalline high explosive compound in said composition having their maximum dimension in the range of about from 0.1 to 50 microns, and said core containing about from 0.1 to 2 grams of crystalline high explosive compound per meter of length;
- (b) core-reinforcement means consisting essentially of at least one continuous strand of yarn on the periphery of said core and running substantially parallel to said core's longitudinal axis, said strand(s) having sufficient tensile strength as to prevent said core from necking down to a failure point under forces normally encountered in borehole loading; and
- (c) a protective sheath of plastic material enclosing said core and strand(s), said plastic material being one which is capable of flowing at a temperature not exceeding the melting point of said crystalline high explosive compound by more than about 75.degree. C.
- 16. A detonating cord of claim 15 wherein said yarn is a multifilament yarn, and the filaments thereof are dispersed around said core.
- 17. A detonating cord of claim 15 wherein said crystalline high explosive compound is selected from the group consisting of pentaerythritol tetranitrate and cyclotrimethylenetrinitramine.
- 18. A detonating cord of claim 17 wherein said explosive composition contains at least about 70 percent by weight of pentaerythritol tetranitrate (PETN), said core contains at least about 0.4 grams of PETN per meter of length, and said sheathing is made of a thermoplastic material.
- 19. A detonating cord of claim 18 wherein said binding agent is plasticized nitrocellulose.
- 20. A detonating cord of claim 18 wherein said thermoplastic material is a polyolefin which is capable of flowing at a temperature below about 200.degree. C.
- 21. A detonating cord of claim 20 wherein said thermoplastic material is polyethylene and said sheathing is about from 0.051 to 0.127 cm thick.
- 22. A detonating cord of claim 18 wherein the thickness of said sheathing is in the range of about from 0.013 to 0.318 cm.
- 23. A low-energy detonating cord consisting essentially of
- (a) a continuous solid core of a deformable bonded detonating explosive composition comprising at least about 70 percent by weight of pentaerythritol tetranitrate (PETN) admixed with a binding agent, the particles of PETN in said composition having their maximum dimension in the range of about from 0.1 to 50 microns, and said core containing about from 0.1 to 2 grams of PETN per meter of length;
- (b) core-reinforcement means consisting essentially of at least four strands of yarn substantially uniformly distributed about and in contact with the periphery of said core, said strands having sufficient tensile strength as to provide said reinforced core with a tensile strength of at least about 9 kilograms; and
- (c) a sheath of thermoplastic material enclosing said core and strands, said thermoplastic material being one which is capable of flowing at a temperature below about 200.degree. C.
- 24. A detonating cord of claim 23 wherein said sheath is about from 0.013 to 0.191 cm inch thick.
Parent Case Info
This application is a continuation-in-part of my co-pending application Ser. No. 762,824, filed Jan. 26, 1977 now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (2)
Number |
Date |
Country |
815257 |
Sep 1974 |
BEX |
1416128 |
May 1974 |
GBX |
Non-Patent Literature Citations (3)
Entry |
Detasheet Flexible Explosive Brochure, A62232. |
Primacord Detonating Cord, The Ensign-Bickford Company, 1963, 11 and 13. |
Blaster's Handbook, p. 107, Dupont. |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
762824 |
Jan 1977 |
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