Patent ID: 8684968

Claim:
A drug delivery apparatus for delivering pressurized fluid, comprising: a. at least one reservoir forming a sealed package for the fluid and comprising at least one rupturable wall portion; b. a reservoir pressurizing device for pressurizing said reservoir; c. at least one rupturing member for rupturing said rupturable wall portion; d. at least one fluid administration device communicating with said reservoir via a fluid passageway; e. a rupture control mechanism preventing rupture of the wall portion below a threshold pressure, whereby: when the threshold pressure is reached, said wall portion may become ruptured by said rupturing member allowing the fluid to enter the fluid passageway and be delivered to a destination through said fluid administration device; and f. a pressure chamber for use in pressurizing said reservoir, said rupture control mechanism including a resistance mechanism for preventing pressurization of the reservoir before a requisite pressure has been established in said pressure chamber, wherein said resistance mechanism comprises a collapsible spring disposed in said pressure chamber in confronting relationship to said reservoir, said collapsible spring operative to permit gradual pressure build up in said pressure chamber and to thereafter collapse and cause an instantaneous pressure in said reservoir.