| 摘要 |
A device with improved accuracy, repeatability and reliability in collecting a first fluid such as samples of blood in a syringe or other fluids of various volumes in a dispenser, including volumes of a few lambdas and up to a few ounces, and mixing first fluid volume with a second fluid volume ideally measured in quantities of multiples of 1 to 1,000 times the first fluid volume, which operates by means of a built-in positive displacement with cut-off by a reciprocating plunger containing a telescoping spring loaded piston rod assembly and entering a barrel filled with second fluid with provision of collecting a first fluid by suction into a receiver such as pipette through an elongated passage at the barrel end which can also serve as receiver for the first fluid, simultaneously the plunger moves up from the first discharge position to the second filling position. incorporating a means of filling the barrel only when the plunger is at the barrel top and the barrel is under partial vacuum until the plunger seal disengages the barrel rim to enter larger diameter end cap portion connected to a second fluid supply permitting an instantenous barrel filling with second fluid and means for control of volumetric displacement by cut-off when plunger starts to descend closing the barrel rim by the plunger seal and subsequently during downstroke pressurizing second fluid trapped in the barrel to simultaneously disengage the piston rod end from the elongated passage at the barrel end discharging the fluids mixed from the barrel during descend of the plunger and also washing the discharge passage with surplus of second fluid exhausting from the barrel after the first fluid was discharged under pressure of the second fluid therefrom by piston rod reentering the elongated passage by the force of a spring when the pressure of the second fluid dropped at the end of the plunger downstroke rendering the device ready to repeat the cycle of simultaneous filling of two different fluids on upward motion of the plunger and their mixing during the discharge on downward plunger motion, such motion controlled externally by mechanical or electromechanical means such device including volumetric adjustment of second fluid discharge therefrom.
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