| 摘要 |
1,148,241. Projecting device with timer. BECTON, DICKINSON & CO. 5 April, 1966, No. 15207/66. Heading B1X. [Also in Division F1] A pipetting device which may operate to start a timing device for automatically determining reaction time in for example prothrombin tests comprises plunger 22 reciprocable in tubular barrel 24, disposable pipette tip 134 coupled barrel 24 by coupling 132, flanges 42, 44 within the barrel preventing forward movement of the plunger when not appropriately oriented in the barrel, and means for' sewing the plunger with relation to the barrel in a position in which' forward movement of the plunger causes a measured quantity of liquid to be dispensed. The means for setting the plunger may comprise stop flanges (50), 52 within the barrel which cooperate with a plate (114) extending from flange 113 on the rear end of the plunger (Fig. 7 not shown) to limit the extent of forward .movement of the plunger and hence to provide the desired dosage. When liquid is being drawn into tip 134, switch button 88 is in the off position as shown, electrical contacts 68; 70 do not touch and there is no operative connection with timer (80). When liquid is to be dispensed, switch 88 is moved to the on position, contact 70 moves to touch contact 68 (Fig. 3 not shown), forward movement of the plunger moves contact 68 towards contact 66, and the circuit with timer. (80) is completed to start the timer on completion of the forward stroke of the plunger. |
