| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a pump having superior durability capable of exhibiting a superior back suction function without requiring large force during pressing down operation of a working member and in which a structural change is smaller than in the case with a conventional pump. Ž<P>SOLUTION: This pump includes: an annular piston D<SB>4</SB>with its outer peripheral edge slidably fitted with an inner periphery of a cylinder B, mounted to be relatively movable in the up and down direction on an outer periphery of a stem D<SB>1</SB>, for opening a discharge valve hole 41 during descending of the stem D<SB>1</SB>and blocking the discharge valve hole 41 during ascending of the stem D<SB>1</SB>; and a back suction mechanism in which an upper end of a bar part 36 is slidably projected inside a lower part of the stem D<SB>1</SB>from a lower end opening of the stem D<SB>1</SB>, the capacity inside the stem D<SB>1</SB>is increased by the upper end of the bar part 36 relatively descending during ascending of the stem D<SB>1</SB>, and the capacity inside the stem D<SB>1</SB>is decreased by the upper end of the bar part 36 relatively ascending during descending of the stem D<SB>1</SB>. The discharge valve hole 41 is provided having a vertical length from a lower most descending position in the stem D<SB>1</SB>of a tip end edge of the bar part 36 to an upper most ascending position in the stem D<SB>1</SB>of the tip end of the bar part 36. Ž<P>COPYRIGHT: (C)2010,JPO&INPIT Ž</p> |
