US Patent 7063684 Drive system seal

A pump for dispensing a fluid from a reservoir provides a drive system seal within the pump. The pump includes a reservoir cavity adapted to receive the reservoir, and a drive system. The pump also includes at least one plunger slider having one end coupled to the drive system and the other end coupled to the reservoir. The plunger slider is adapted to translate from a retracted position to an extended position to dispense the fluid from the reservoir in response to actuation by the drive system. The pump further includes a sealing ring mounted around the plunger slider, and a spring disposed within the sealing ring. The sealing ring with the spring disposed therein is adapted to allow the plunger slider to translate from the retracted position to the extended position, and to prevent entry of fluid from the reservoir cavity into the drive system.