Patent ID: 7608055

Claim:
An automatic injection device containing a pre-loaded charge of medicament for automatically self-administering the medicament upon actuation thereof, the device comprising: a housing; a medicament chamber disposed in the housing, the medicament chamber including a first compartment containing a first medicament portion, and a second compartment containing a second medicament portion to be mixed with the first medicament portion; a seal structure between the first compartment and the second compartment, the seal structure being initially in a sealing condition that maintains the first compartment separate from the second compartment, the seal structure being converted to a mixing condition as a result of activation of the device; a needle assembly that dispenses the medicament charge from the medicament chamber, the needle assembly having a rearward opening with a diameter that is less than a diameter of the medicament chamber; an insert mounted in a forward end of the medicament chamber adjacent the needle assembly, the insert defining a tapering flow pathway that tapers radially inward as it extends axially forward, the insert having a constant radially-inward taper as fluid flows through the insert, the constant radially-inward taper extending from the end of the insert that forms a common boundary with the medicament chamber to the opposite end of the insert that forms a common boundary with the needle assembly; an activation assembly carried by the housing and including a stored energy source, wherein activation of the activation assembly releases the stored energy from the stored energy source, causing the seal structure to be converted from the sealing condition to the mixing condition, and thereby causing or allowing the first and second medicament portions to be mixed, directed by the insert radially inward toward the rearward opening in the needle assembly, and forced through the needle assembly.