| 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 A 1, and a cross-sectional area A 0 , or a cumulated cross-sectional area at most A 2, and a cross-sectional area A 0 . A 1 and A 2 are substantially smaller than A 0 . 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. |
