Claims
- 1. In a non-electric blasting assembly comprising
- (a) a percussion-actuated detonator comprising a tubular metal detonator shell integrally closed at one end and closed at the other end by a partially empty, shorter tubular metal primer shell having an open end and supporting a percussion-sensitive primer charge adjacent the inside surface of an integrally closed end, said primer shell extending open end first into said detonator shell to dispose the outside surface of its primer charge end across the end of said detonator shell, said detonator shell containing, in sequence from its integrally closed end, (1) a base charge of a detonating explosive composition and (2) a priming charge of a heat-sensitive detonating explosive composition; and
- (b) low-energy detonating cord (LEDC) adjacent the outside end surface of said primer shell; the improvement comprising a length of LEDC arrayed in a manner such that a pair of axially separated segments thereof are anchored in place, or two lengths of LEDC arrayed in a manner such that a segment from each length is anchored in place, in side-by-side relationship adjacent the outside end surface of said primer shell.
- 2. A blasting assembly of claim 1 wherein said detonator and said length(s) of LEDC are held in a connector for holding donor and receiver detonating cords in propagating relationship to a detonator.
- 3. A blasting assembly of claim 1 wherein said length of LEDC is looped so as to form a U-shaped or circular cord portion with arm portions adjacent thereto, said pair of axially separated segments being located one in each of said arm portions.
- 4. A blasting assembly of claim 3 wherein said axially separated segments both are substantially in contact with said primer shell end surface.
- 5. A blasting assembly of claim 3 including a tube whose bore receives the input end of said detonator and which has, at one end thereof, a transverse slot communicating with said bore and engaging said length of LEDC so that said pair of segments are positioned adjacent the outside end surface of said primer shell, said tube being provided with locking means adjacent said transverse slot for preventing the disengagement of said looped cord therefrom.
- 6. A blasting assembly of claim 3 including a sleeve which fits over the primer shell end of said detonator shell, or is sandwiched between said primer shell and said detonator shell, said sleeve having a loop-like projection diametrically disposed beyond the integrally closed end of said primer shell, and said length of LEDC being threaded through said projection.
- 7. A blasting assembly of claim 6 wherein said projection is U- or M-shaped and one free end of said length of LEDC is threaded through said projection in a given direction and a second time in the same direction after said cord end has been doubled back to form a circular cord portion whose diameter may be reduced by the application of tension to one or both of the arm portions adjacent thereto.
- 8. A blasting assembly of claim 6 wherein said length of LEDC is threaded through said projection in a manner such that a U-shaped portion thereof extends beyond the wall of said detonator shell.
- 9. A blasting assembly of claim 6 wherein said length of LEDC is threaded through said projection in a manner such that a U-shaped portion thereof is positioned along the rim of the integrally closed end of said primer shell.
- 10. A blasting assembly of claim 8 wherein said projection is U- or M-shaped, and a free end of said length of LEDC is doubled back over said projection and threaded through said U-shaped portion of cord, said free end being locked in place in said U-shaped portion of cord when tension is applied to an arm portion adjacent thereto.
- 11. A blasting assembly of claim 8 wherein said projection is U-shaped, and said U-shaped portion of cord is passed over the integrally closed end of said detonator shell to the opposite side thereof whereby said U-shaped portion of cord is wedged against the detonator shell as tension is applied to one or both of said arm portions.
- 12. A blasting assembly of claim 8 or 9 wherein said projection is M-shaped and so dimensioned as to prevent the passage of said U-shaped portion of cord therethrough when tension is applied to one or both of said arm portions.
- 13. In a non-electric blasting assembly comprising:
- (a) a percussion-actuated detonator comprising a tubular metal detonator shell integrally closed at one end and closed at the other end by a partially empty, shorter tubular metal primer shell having an open end and supporting a percussion-sensitive primer charge adjacent the inside surface of an integrally closed end, said primer shell extending open end first into said detonator shell to dispose the outside surface of its primer charge end across the end of said detonator shell, said detonator shell containing, in sequence from its integrally closed end, (1) a base charge of a detonating explosive composition and (2) a priming charge of a heat-sensitive detonating explosive composition;
- (b) a substantially U-shaped segment of a length of receiver detonating cord held with its apex adjacent the integrally closed end of said detonator shell; and
- (c) low-energy detonating cord (LEDC) adjacent the outside end surface of said primer shell; the improvement comprising a length of LEDC arrayed in a manner such that a pair of axially separated segments thereof are anchored in place, or two lengths of LEDC arrayed in a manner such that a segment from each length is anchored in place, in side-by-side relationship adjacent the outside end surface of said primer shell.
- 14. A blasting assembly of claim 1 or 13 wherein said LEDC comprises a core of granular pentaerythritol tetranitrate having a specific surface of about from 900 to 3400 square centimeters per gram confined within a woven textile sheath.
- 15. A blasting assembly of claim 1 or 13 wherein said LEDC comprises a continuous solid core of a deformable bonded detonating explosive composition comprising a 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, surrounding said explosive core, protective sheathing comprising one or more layers of plastic material.
- 16. A blasting assembly of claim 15 wherein the explosive loading of said core of bonded explosive is about from 0.1 to 2 grams per meter of length.
- 17. A blasting assembly of claim 13 wherein said detonator and said lengths of cord are held in a connector comprising:
- (a) a central tubular portion whose bore receives said detonator;
- (b) a cord-housing section at each end of said tubular portion and communicating with the bore thereof; and
- (c) two tapered pins, one mateable with each of a pair of matched apertures oppositely disposed in each of said cord-housing sections, said pins being adpated to extend through said apertures in a manner such as to hold said cord segments adjacent the ends of said detonator.
- 18. A blasting assembly of claim 17 wherein said side-by-side segments are substantially U-shaped segments held with their apexes adjacent said primer shell end surface.
- 19. A blasting assembly of claim 17 wherein said side-by-side segments are substantially U-shaped segments held in apex-to-apex contact, a first of said segments being substantially in contact with said primer shell end surface, and a second nested within the first.
- 20. A blasting assembly of claim 17 wherein said side-by-side segments are segments of a length of LEDC which is looped so as to form a U-shaped cord portion with arm portions adjacent thereto, said pair of axially separated segments being located one in each of said arm portions.
- 21. In a percussion-actuated detonator comprising a tubular metal detonator shell integrally closed at one end and closed at the other end by a partially empty, shorter tubular metal primer shell having an open end and supporting a percussion-sensitive primer charge adjacent the inside surface of an integrally closed end, said primer shell extending open end first into said detonator shell to dispose the outside surface of its primer charge end across the end of said detonator shell, said detonator shell containing, in sequence from its integrally closed end, (1) a base charge of a detonating explosive composition and (2) a priming charge of a heat-sensitive detonating explosive composition, the improvement comprising a sleeve which fits over the primer shell end of said detonator shell, or is sandwiched between said primer shell and said detonator shell, said sleeve having a generally M-shaped loop-like projection diametrically disposed beyond the integrally closed end of said primer shell, and said loop being adpated to have one or two lengths of LEDC threaded therethrough to position a pair of segments anchored in place in side-by-side relationship adjacent the outside end surface of said primer shell.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of my co-pending Application Ser. No. 257,973, filed Apr. 27, 1981.
US Referenced Citations (11)
Non-Patent Literature Citations (1)
Entry |
E. I Du Pont de Nemours & Co., Blasters' Handbook, 175th Anniversary Ed., 1977, pp. 104 and 132. |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
257973 |
Apr 1981 |
|