Inductive store opening switch

William F. Weldon
Journal Title
Journal ISSN
Volume Title
United States Patent and Trademark Office

The inductive store opening switch includes a cartridge casing comprising a length of metal tubing, for disposition between a pair of electrical buss bar conductors and in contact with both so as to establish a path for electrical current therethrough. The tubular casing, having inner and outer surfaces, is scored on its outer surface to establish a rupturing point. The scoring on the outer surface may constitute many different geometric forms. A solid body of inert material is insertable within the casing and disposed adjacent the rupturing point of the casing. A propellant cartridge carrying a combustible material, such as gun powder, is disposed within the casing opposite the inserted body so as to define a cavity volume within the casing proximate the rupturing point of the casing. The cartridge further includes structure for igniting the material. The oxidation-gas products produced by ignition of the material in the propellant cartridge expand into the volume defined within the casing and cause rupturing of the casing along the scoring, thereby breaking the electrical current path established by the casing. Reinforcement members extending circumferentially of the casing on opposite sides of the scoring, may be used to control the extent of rupturing of the casing and control the gap width between casing halves. Alternatively, the casing may be ruptured by introduction of a pressurized fluid by the dumping of fluid from a high pressure accumulator into the cavity volume using a fast-acting valve.