Patent ID: 8708961

Claim:
An infusion device, comprising a housing including a control portion and a reservoir portion separable from the control portion; a precise drive including a piezoelectric bender assembly having a piezoelectric bender with a first end fixed relative to the control portion and a second end movable relative to the first end, a limiter fixed to the control portion including a first limiter end having a rest stop and a second limiter end having an actuator stop, the rest stop and the actuator stop defining a dimensionally stable limiter gap, the piezoelectric bender assembly extending into the limiter gap to define a stroke gap between the limiter and the piezoelectric bender assembly in the limiter gap, and a resilient device biased against the piezoelectric bender assembly to move with the piezoelectric bender assembly and having a resilient stroke greater than the stroke gap, the resilient device acting in opposition to the bender assembly with the bender assembly exhibiting greater force than the resilient device when the bender assembly is electrified, the piezoelectric bender assembly being capable of a stroke which is greater than the stroke gap allowed by the limiter; a pump including a cylinder and a piston capable of reciprocation in the cylinder, the piston engaged to move with the resilient device, the resilient device and the pump being in the reservoir portion.