| 摘要 |
PURPOSE: To provide a repeatable pipette which is operable very simply. CONSTITUTION: A piston retraction means 10 move a receiving member 9 with a piston receiving part in the direction separating from a receiving part 5 of an injector. A pawl 22 is engaged with a tooth train 14 of a rack 13 during the advancing of an operation element 17 to get the rack advanced by a fixed stroke, but it is not engaged with the tooth of the rack during the retraction thereof. A check element 23 is so arranged to be movable along the rack with a rotary knob 27 to block the engagement of the pawl with the rack. A contact member 29 is so controlled to cause an increase in the length of the stroke in the operation element when the length of the stroke of the rack is increased by the check element and the rotary knob 27, and to cause a decrease in the length of the stroke in the operation element when the length of the stroke of the rack is decreased. |
