| 摘要 |
Piston structure having a first side and a second side and in a recess (6) formed in an outer portion of the piston (1, 22) a resilient sealing element (5, 11, 21) is placed. The axial width and at least in some places the radial depth of the recess (6) are greater than the cross-sectional diameter of the sealing element (5, 11, 21) which is able to move, owing to the pressure difference of the two sides, between a first and a second position, thereby alternately ensuring a cumulated cross-sectional area at most A1, and a cross-sectional area A0, or a cumulated cross-sectional area at most A2, and a cross-sectional area A0. A1 and A2 are substantially smaller than A0. The invention further relates to a liquid feeder valve including this piston structure for allowing liquid flow-through in a certain amount or for a period of time from a pressurized source of liquid. |
