초록 ▼

The ignition assembly of a non-electric delay detonator which is adapted for field-assembly with a low-energy detonating cord has an expansion shell provided with a cavity into which the cord is inserted at the time of use. The pressure pulse resulting from the detonation of the cord causes the shel

The ignition assembly of a non-electric delay detonator which is adapted for field-assembly with a low-energy detonating cord has an expansion shell provided with a cavity into which the cord is inserted at the time of use. The pressure pulse resulting from the detonation of the cord causes the shell to expand and an ignition charge to be actuated as a result of sudden compression between the expansion shell and a rigid ignition capsule. The burning ignition charge causes the ignition of a delay charge, which in turn ignites a priming charge, causing the base charge to detonate. The presence of ignition charge in an annular spacing between the expansion shell and ignition capsule walls, as well as between the shell and capsule ends, and the proper positioning of a cord-gripping means, preferably in the shell cavity, assure actuation of the ignition charge whether or not the cord is shoved to the bottom of the shell.

대표청구항 ▼

In a non-electric delay detonator adapted to be actuated by a low-energy detonating cord and comprising a tubular metal detonator shell integrally closed at one end and containing, in sequence from the closed end, (a) a base charge of a detonating explosive composition, (b) a priming charge of a hea

In a non-electric delay detonator adapted to be actuated by a low-energy detonating cord and comprising a tubular metal detonator shell integrally closed at one end and containing, in sequence from the closed end, (a) a base charge of a detonating explosive composition, (b) a priming charge of a heat-sensitive detonating explosive composition, (c) a delay charge of an exothermic-burning composition, and an ignition charge, the improvement comprising an assembly, to be used in conjunction with said detonating cord, for igniting said delay charge, said assembly comprising: (1) a tubular rigid metal ignition capsule having one open extremity and a closure at the other extemity, said capsule being nested within said detonator shell in a manner such that said closure is directed toward said delay charge; (2) a tubular metal expansion shell integrally closed at one end, said expansion shell being deformable and positioned coaxially within said detonator shell in a manner such as to produce a spacing between the side walls of said expansion shell and of said ignition capsule, and between the closed end of said expansion shell and the closure on said ignition capsule; and (b 3) a percussion-sensitive ignition charge in the spacing between the side walls of said expansion shell and of said ignition capsule, and between the closed end of said expansion shell and said closure on said ignition capsule, said closure on said ignition capsule having an axial perforation or being adapted to be axially perforated by the burning of said ignition charge, and said delay charge being adapted to be ignited as a result of the burning of said ignition charge; means being provided for sealing the charges in said detonator shell off from the atmosphere and for preventing the venting of gases resulting from the burning of said ignition charge, an open cavity extending from one end to the other of said expansion shell for receiving a low-energy detonating cord adapted by its detonation to produce a pressure pulse that causes the ignition of said ignition charge, and means being provided for retaining said cord coaxially in said cavity.