| abstract |
A medication dispensing apparatus having a gear set (64) to provide a mechanical advantage to the plunging of the apparatus plunger (66). The gear set (64) has a first pinion (114) in meshed engagement with a rack of the plunger (102), and a second pinion (126) in meshed engagement with a rack of a drive member (80) of the apparatus. The gear set (64) operatively interconnects the plunger (66) and the drive member (62) such that after the plunger (66) is moved relative to the housing in a proximal direction to prepare the apparatus for injection, the plunger (66), when manually pushed back toward the housing, causes the drive member (62) to advance in a distal direction to force medication through an outlet, typically provided with an injection needle, at the distal end of the apparatus. |