Mixing and dispensing disposable medicament injector

A mixing and dispensing disposable medicament injector adapted to mix a liquid diluent and a dry medicament and have means for injecting said mixed medicament, said injector comprising:

• a cylindrical barrel,
• a slidable plunger fitted with end closing off the rearward end of the barrel, said plunger including a body portion having its periphery in sealing contact with the barrel, said body portion having a central opening extending longitudinally therethrough, a cap member centrally positioned in said opening with its closed end facing forwardly, a flexible support connected to the wall of the opening and the cap member to close off the opening,
• a plunger rod having an end prolongation of reduced diameter, said reduced diameter portion fitting within the cup member,
• a first diaphragm assembly positioned within and closing off the forward end of the barrel, said first diaphragm assembly comprising a body portion having its periphery in sealing engagement with the barrel, a central opening in said body portion, a flexible wall closing off the rearward side of the central opening, a first needle positioned in the central opening with its pointed end closely adjacent the flexible wall, the other end of the needle establishing flow communication with the forward side of the body portion,
• a second diaphragm assembly sealingly and slidably fitted within the barrel intermediate the ends thereof dividing the barrel into a rearward chamber adapted to contain the liquid diluent and a forward chamber adapted to contain the dry medicament, said second diaphragm assembly including a body portion having its periphery in sealing engagement with the barrel, a central opening in said body portion, a flexible wall closing off the rearward side of the central opening, a second needle carried in the central opening with its pointed end closely adjacent the flexible wall, the other end of the needle establishing flow communication with the forward chamber, said second needle being independent of the first needle and slidably carried and supported by the second diaphragm which is slidable within the same common barrel with the plunger, and
• a cannula assembly affixed to the forward end of the barrel in flow communication with the forward side of the first diaphragm assembly.

A mixing and dispensing disposable medicament injector adapted to mix a liquid and a dry medicament and have means for injecting said mixed medicament, said injector comprising:

• a cylindrical barrel,
• a slidable plunger fitted within and closing the rearward end of the barrel,
• a first diaphragm assembly positioned within and closing off the forward end of the barrel,
• a second diaphragm assembly sealingly and slidably fitted within the same barrel in which the plunger is slidable, and positioned intermediate the ends thereof dividing the barrel into a rearward chamber and a forward chamber, the rearward chamber being adapted to contain the liquid diluent and the forward chamber being adapted to contain the dry medicament, each diaphragm assembly including a flexible wall on its rearward side with piercing means mounted adjacent the forward side of said flexible wall, said piercing means for the second diaphragm being supported by and slidably carried by the second diaphragm in the same barrel in which the plunger is slidable, whereby when the flexible walls are flexed said walls will be pierced by the respective piercing means to allow fluid flow forwardly through the flexible walls.