AU2011221472B2 — Automatic injection device with delay mechanism including dual functioning biasing member

USPTO Abstract

An automatic injection apparatus including a delay mechanism for properly delivering medication prior to the needled syringe of the apparatus being retracted. In one form, the delay mechanism includes a shuttle ( 170 ) for the syringe, a follower ( 250 ), a locking member, a damping compound between the follower and a supporting surface ( 308 ) to dampen rotation of the follower relative to the shuttle, and a dual functioning biasing member ( 29 0 ) acting between the shuttle and the follower. When the locking member moves to a release position during an injection, the dual functioning biasing member first provides a torsional force to force the follower to rotate relative to the shuttle from a latching position to an unlatching position, and then the dual functioning biasing member provides an axial force to force the shuttle axially relative to the follower to move the shuttle for retracting the syringe needle into the housing of the apparatus after injection.