Patent ID: 8186274

Claim:
A method for making a cartridge for the controlled delivery of a fluid, comprising: a. providing a high pressure case, having a closed first end, an open second end, and a continuous side wall running between said first and second ends, thereby defining a hollow interior; b. providing propellant, contained within said hollow interior of said high pressure case; c. providing a domed burst cup, having an internal surface and an external surface, and having an open first end and a closed second end thereby defining a hollow interior within said burst cup, with said burst cup being placed within said open second end of said high pressure case; d. providing a low pressure cartridge, said low pressure cartridge including a high pressure cartridge receiver having an inner charge casing wall; e. providing a step in said inner charge casing wall; and f. forcing said high pressure case and said domed burst cup into said high pressure cartridge receiver so that said continuous side wall of said high pressure case slides against said inner charge casing wall and is deformed as said continuous side wall passes over said step to form a neck in said continuous side wall which laps over said external surface of said domed burst cup, thereby trapping said burst cup in said high pressure case.