WET/DRY AUTOMATIC INJECTOR ASSEMBLY

摘要

An automatic injection device containing a pre-loaded charge of medicament for automatically administering the medicament upon actuation thereof. The device comprises a housing and a chamber disposed in the housing. The chamber has a first compartment and a second compartment, the first compartment containing a first medicament portion and the second compartment containing a second medicament portion to be mixed with the first medicament portion. A seal structure is provided between the first compartment and the second compartment. The seal structure initially in a sealing condition that maintains the first compartment separate from the second compartment and converting to a mixing condition in response to activation of the device. A needle assembly dispenses the medicament charge from the chamber, the needle assembly having a rearward opening with a diameter that is less than a diameter of the chamber. An insert is mounted in a forward end of the chamber adjacent the needle assembly, the insert defining a tapering flow pathway that tapers radially inwardly as it extends axially forward, the insert having a constant radially-inward taper as fluid flows through the insert, the insert sealingly engaging inner walls of the chamber. An activation assembly disposed in the housing, wherein activation of the activation assembly causes (1) the seal structure to be converted from the sealing condition to the mixing condition, (2) the first and second medicament portions to be mixed, and (3) the mixed first and second medicament portions to be directed by the insert radially inwardly toward the rearward opening of the needle assembly.