Thermal detonation energy-initiatable blasting caps, and detonation system and method

Claim 2

A nonelectrically initiated blasting cap which comprises a closed shell; an initiator charge in said shell ignitable in response to action of thermal detonation energy of an explosive gas mixture and said shell containing an open space adjacent said initiator charge; a first conduit means extending from outside said shell into said opeN space in direct open communication with said initiator charge so as to convey an explosive gas mixture as a confined stream into detonating position in said open space for responsive ignition of said initiator charge; a second conduit means permitting said open space to be purged of gases other than said explosive gas mixture prior to detonation of said confined stream for said responsive ignition extending from said open space to the outside of said shell, whereby a stream of said explosive gas can be continuously passed from said first conduit means through said open space and through said second conduit means to purge said open space as described and thereafter explosive gas in said first conduit means can be detonated for propagation of resulting thermal detonation energy to said open space for ignition of said ignition charge.

Claim 3

In a blasting cap of claim 1, said shell being elongated, and a plug closure member therefor; an ignition charge, as said initiator, in spaced apart relationship with said plug to provide said open space; base, primer and said ignition charges, with or without a delay charge intermediate said primer and ignition charges, extending in that order toward said plug closure and said first conduit means comprising a tube extending from outside said shell through said plug closure and opening into said open space.

Claim 4

In a blasting cap of claim 2, said second conduit means comprising a passageway in a side wall of said shell.

Claim 5

In a blasting cap of claim 2, said second conduit means comprising an additional tube extending through said plug closure.

Claim 6

A detonator system for detonation of one or more main charges comprising a plurality of spaced apart nonelectrically initiated blasting caps, each said blasting cap comprising (1) a closed shell, (2) an initiator charge in said shell ignitable in response to action of thermal detonation energy of an explosive gas mixture and said shell containing an open space adjacent said initiator charge; (3) a first conduit means extending from outside said shell into said open space in direct open communication with said initiator charge so as to convey an explosive gas mixture as a confined stream into detonating position in said open space for responsive ignition of said ignition charge, or to convey said explosive gas mixture as a purge stream for said open space, and (4) a second conduit means extending from said open space to the outside of said shell for egress purge flow of said explosive gas mixture from said open space prior to detonation of said confined stream for said responsive ignition; a third conduit means external to said plurality of blasting caps connecting through each said first conduit means for conveying a confined stream of said explosive gas mixture thereinto; and means for detonating said explosive gas mixture when confined in said third conduit means.

Claim 7

A detonator system for detonation of one or more main charges comprising a plurality of spaced apart nonelectrically initiated blasting caps, each said blasting cap comprising (1) a closed shell, (2) an initiator charge in said shell ignitable in response to action of thermal detonation energy of an explosive gas mixture and said shell containing an open space adjacent said initiator charge; (3) a first conduit means extending from outside said shell into said open space in direct open communication with said initiator charge so as to convey an explosive gas mixture as a confined stream into detonating position in said open space for responsive ignition of said ignition charge, or to convey said explosive gas mixture as a purge stream for said open space, and (4) a second conduit means extending from said open space to the outside of said shell for egress purge flow of said explosive gas mixture from said open space prior to detonation of said confined stream for said responsive ignition; a third conduit means external to said plurality of blasting caps connecting through each said first conduit means for conveying a confined stream of said explosive gas mixture thereinto; and means for detonating said explosive gas mixture when confined in said third conduit means.

Claim 8

In a detonator system of claim 5, each said blasting cap shell being elongated and a plug closure member therefor; an ignition charge, as said initiator charge, disposed in each said shell in spaced apart relationship with said closure plug therein to provide said open space; base, primer and said ignition charges in each said shell, with or without a delay charge intermediate said primer and ignition charges, extending in that order toward said plug closure; and said first conduit means in said each shell extending from outside said shell through said plug closure and opening into said open space.

Claim 9

In a detonator system of claim 6, each said blasting cap containing as said first conduit means a first tube extending through the closure plug thereof, and as said second conduit means a second tube extending through said closure plug.

Claim 10

In a detonator assembly of claim 6, each said blasting cap containing as said second conduit means a passageway in a side wall of the shell.

Claim 11

In a detonator system of claim 7 said third conduit means connecting with said first tube of A first of a series of said blasting caps, and said first tube of each succeeding blasting cap connecting with said second tube of a preceding blasting cap so as to dispose said blasting caps for series flow of confined, or purging, gas therethrough.

Claim 12

In a detonator system of claim 8, said third conduit means extending outside said plurality of blasting caps, and the first conduit means of each blasting cap connecting in open communication with said third conduit means so as to receive a separate flow of said explosive gas mixture therefrom.

Claim 13

In a detonator system of claim 10, means for detonating said explosive gas mixture when confined in said third conduit means upstream from said blasting caps.

Claim 14

In a detonator system of claim 7, said shell of each said blasting cap being integrally closed at one end, and an ignition plug, as said plug closure, closing said shell at the other end; base, primer, delay and said ignition charges in each said blasting cap extending in that order toward said ignition plug from the integrally closed shell end; as said third conduit means, a third tube connecting at one end with a source of said explosive gas mixture and at the other end with said first tube of a first of a series of said blasting caps; and said first tube of each succeeding blasting cap connecting with said second tube of a preceding blasting cap so as to dispose said blasting caps for series flow of confined, or purging, gas therethrough.

Claim 15

In a detonator system of claim 12, means for mixing oxidizer and fuel ingredients to form said explosive gas mixture connecting with said third tube as said source of explosive gas mixture.

Claim 16

A detonator system of claim 13 in detonating relationship with at least one main explosive charge.

Claim 17

A detonator system of claim 14 in which at least one said main explosive charge is cap-insensitive, and said detonator system including booster charge means for detonation of said cap-insensitive charge.

Claim 20

A method of claim 16 wherein said confined explosive gas is passed into and through a plurality of said blasting caps prior to detonating same.