Hypodermic jet injector and cartridge therefor

Claim 1

A medicament containing integral cartridge adapted to be used with a jet injector gun, the gun comprising an elongated hollow body having an opening in one end; piston means positioned in the elongated body to move axially and longitudinally within the elongated body, spring means urging the piston means toward the opening, trigger means adapted to releasably hold the piston means away from the opening in opposition to the urging of the spring means, a plunger affixed to the piston means and extending through the opening in the elongated body; and cartridge engaging means affixed to the one end of said elongated body, the cartridge engaging means comprising a shoulder and a slot, the shoulder connected to the exterior of the elongated body adjacent to the opening in the one end of the elongated body, the slot positioned between the shoulder and the body, transverse to the axis of the elongated body; said integral cartridge comprising: an elongated tube having a closed end and an open end, an orifice positioned in said closed end; an interrupted flange molded as a part of said tube adjacent to said open end, said flange extending transverse to the axis of said tube; and a collar molded as part of said tube and forming a longitudinal extension of said tube extending beyond said interrupted flange, at said open end, of said tube; a plug slidably positioned in the open end of said tube of said cartridge and a medicament in the space defined by said tube and said plug; said collar and said flange defining means for cooperatively engaging said cartridge engaging means so that said cartridge is removably locked onto the gun by inserting said collar into the opening in said one end of the elongated body of the gun with the interruption in said flange passing over the shoulder, surrounding the plunger with said collar, and rotating the cartridge to engage said interrupted flange with the slot in the shoulder and thereby lock said cartridge to the gun to maintain said cartridge in a locked position when the trigger means releases said piston means and the spring means urges the piston means toward the opening.