PUMP

摘要

An improved pump capable of achieving excellent back suction function without compromising the ease of depression operations of the head is provided. The pump includes a depression head D5 and an annular piston D4. The head D5 is urged upward and also relatively displaceable with respect to the stem D1, and configured such that, when depressed, a lever member D7 operates to open a discharge opening 81 by displacing an opening-closing valve member D6 that is urged toward a discharge opening 81, and that a resistive force against the depression of the head D5 with respect to the stem is smaller than a resistive force against the depression of the stem itself The piston D4 opens a discharge valve 73, which the piston D4 forms in cooperation with a discharge valve seat 40, in an uppermost displacement position and closes the valve 73 in a lowermost displacement position.