Patent ID: 8142392

Claim:
A milk pump for pumping milk from a woman's breast, comprising: a milk collector for receiving milk pumped from said woman's breast; a manual pumping unit which includes: a wall forming and surrounding a displacement space, said displacement space defining a longitudinal axis and having a predetermined cross-sectional dimension; a connector for connecting said displacement space to a breast hood; a suction unit displaceable in said displacement space formed by the wall, substantially along said longitudinal axis, said suction unit being formed as a membrane; and an actuator for mechanically displacing said membrane substantially in an axial direction, wherein the suction unit includes a circumferential outer edge border portion at one end which is fixed to the wall, a bottom portion extending substantially transversely to the longitudinal axis at another end and an extending portion extending between the border portion and the bottom portion, the extending portion varying in thickness in a direction along the longitudinal axis, said variations providing a spring characteristic and being formed as a plurality of grooves and/or rings, said extending portion being able to move substantially free of friction relative to said wall.