Patent ID: 8757449

Claim:
An air bubble ingress prevention mechanism mountable to a discharge device including a metering section having a flow passage communicating with a nozzle and a plunger reciprocally movable in the flow passage of the metering section, at an end of the discharge device on the opposite side from the nozzle, the air bubble ingress prevention mechanism comprising: a first hole communicating with the flow passage of the metering section and allowing the plunger to reciprocally move therein, a first sealing member disposed at an end of the first hole on the side closer to the nozzle, a second sealing member disposed at an end of the first hole on the opposite side from the nozzle, and a second hole communicating with a side surface of the first hole, wherein inner peripheries of the first and second sealing members are substantially equal in size to an outer periphery of the plunger, and wherein outer peripheries of the first and second sealing members are greater than an inner periphery of the first hole.