Patent ID: 9446202
Filing Date: 2016-09-20
CPC Classification: A61M

Claim Text:
1. A drive mechanism for a drug delivery device, comprising: a body having a distal end and a proximal end, which are spaced apart in the direction of an axis, a plunger arranged within the body, the plunger having a first engaging portion and a second engaging portion, the first engaging portion including a plurality of protruding elements, the second engaging portion including a sawtooth structure, a lever arranged within the body, the lever having a first pivot that is stationary with respect to the body in the direction of the axis, a second pivot, and a third pivot formed by an engaging element of the lever, wherein the first, second, and third pivots are arranged such that a rotation of the lever with respect to the first pivot moves the second pivot and the third pivot in a same direction with respect to the axis, wherein the engaging element and the first engaging portion are shaped such that the lever is disengaged from the plunger when the second pivot is moved relatively to the plunger in a proximal direction toward the proximal end, and the plunger is engaged with the lever when the second pivot is moved in a distal direction toward the distal end, and a first resilient element having a cantilever portion, the cantilever portion including a hook having a sloping profile, wherein the cantilever portion engages the lever to bias the engaging element towards engagement with the first engaging portion, and wherein the hook of the first resilient element engages with a sawtooth of the sawtooth structure, thus inhibiting the plunger from moving in the proximal direction, wherein the first resilient element is configured to disengage from the second engaging portion, by deflecting the cantilever portion such that the sloping profile slides over the sawtooth, when the plunger is moved in the distal direction, and wherein the first resilient element is engaged with the second engaging portion when the second pivot is moved in the proximal direction.