Activator closure for two-compartment vial

Claim 1

In a closure structure for a two-compartment vial having an open neck at one end thereof, said closure structure including a resilient stopper for sealingly closing the open neck of said vial and a cap joined to said vial for retaining the stopper therein, said stopper including a first annular stopper portion sealingly seated within said neck and a second stopper portion coaxially aligned with and protruding outwardly of said vial from said first stopper portion, said second stopper portion being of substantially reduced diameter relative to said first stopper portion so as to define an outwardly directed shoulder at the interface therebetween, and said cap including an annular gripping portion which surrounds said neck for securing said cap to said vial, said gripping portion including an annular platelike portion which overlies the axial end face of said neck and projects radially inwardly thereof so as to radially overlap the shoulder formed on said stopper to prevent withdrawal of the stopper from the vial, the cap also including a sleeve portion which closely surrounds the second stopper portion and has the lower axial end thereof positioned opposite but spaced upwardly a selected distance from said shoulder, said sleeve portion in the vicinity of the lower end thereof being rigidly and integrally joined to said platelike portion by a fracturable connection, said sleeve portion being sized so as to be movable into the vial neck during activation, the improvement comprising one-way locking structure coacting between the sleeve portion and said stopper for preventing the stopper from being moved inwardly of the vial relative to the sleeve portion after the closure structure has been activated, said one-way locking structure permitting said sleeve portion during initial activation thereof to be axially moved relative to said second stopper portion until the lower end of said sleeve portion abuts said shoulder, said one-way locking structure becoming engaged at this latter intermediate position to prevent the stopper from being depressed inwardly of the vial independently of the sleeve portion.