| 摘要 |
Mechanical pipette with adjustable volume value of aspirated liquid is built of a handle (1) and a nozzle (3) and coupled with them: an ejection mechanism of a pipette exchangeable tip (8), a drawing up and discharging mechanism with a plunger (33) mounted in said pipette nozzle (3), a plunger working stroke adjustment mechanism, a manually actuated lock mechanism of a drive assembly of an adjustment screw of the plunger working stroke, a mechanical counter, a drive mechanism of a mechanical counter and a calibration mechanism for correction of the pipette accuracy deviation. The ejection mechanism applied in the pipette constitutes a hand operated second-class lever the rotating axis of which is perpendicular to the pipette axis and is situated on the other side of the pipette axis than the point of application by the user to a push button (4) of a force actuating via intermediate means the ejector (2). The points of force transfer from the push button (4) to the intermediate means during the angle movement of the push button (4) displace along rectilinear contact surfaces (4c) of the push button (4). The calibration mechanism, preferably, comprises, mounted in the mechanical counter, releasable coupling means for complete disengagement of a revolvers assembly from the mechanical counter drive mechanism in CALIBRATION MODE, further, engaged with them, changeover means for changing over the pipette into CALIBRATION MODE and resetting means of the indication of the liquid volume value on the counter in CALIBRATION MODE. The subject-matter invention relates also to an electric pipette for transferring a liquid, which is provided with the above mentioned ejection mechanism. |
