Patent ID: 9707352
Date: 2017-07-18
CPC Classifications: A61M,Y10T

Claim:
1. A drug delivery device comprising: a housing comprising a distal end and a proximal end, a cartridge adapted and arranged to contain at least one dose of a drug, a bung being movably arranged within the cartridge, wherein in an initial state of the device, the bung is arranged in a proximal end position with respect to the cartridge, a piston rod adapted and arranged to move the bung in the distal direction with respect to the cartridge for delivering a dose of the drug, wherein the device comprises a mechanism operable such that, after a dose delivery operation is completed, the piston rod is moved into the proximal direction with respect to the bung by a back off distance (D), and wherein in the initial state, a distance between a distal end of the piston rod and a proximal end of the bung is greater than zero, with the distance between the piston rod and the bung in the initial state being defined by the back off distance (D).