Dispenser adapted for ultra-micro range

Claim 1

IN A LIQUID DISPENSER HAVING A LONGITUDINAL PASSAGEWAY FOR A PISTON ASSEMBLY, AND A PLUNGER TYPE PISTON ASSEMBLY IN SAID PASSAGEWAY; MEANS FOR ADJUSTABLY CONTROLLING THE STROKE OF SAID PLUNGER TYPE PISTON ASSEMBLY, SAID MEANS INCLUDING A SCALE CARRIED LONGITUDINALLY OF SAID PLUNGER TYPE PISTON ASSEMBLY AND MOVABLE THEREWITH, SAID SCALE HAVING VALUES INCREASING TOWARD THE UPPER END OF SAID PISTON ASSEMBLY, STOP MEANS IN SAID DISPENSER FOR LIMITING DOWNWARD MOVEMENT OF SAID PLUNGER TYPE PISTON ASSEMBLY TO FIX THE DOWNWARD LIMIT OF EACH STROKE, AND A BUSHING SURROUNDING SAID PLUNGER TYPE PISTON ASSEMBLY, SAID BUSHING BEING ADJUSTABLY ASSEMBLED INTO SAID DISPENSER WITH RESPECT TO SAID FIXED STOP, TO CREATE AND ADJUSTABLE UPPER STOP FOR SAID PLUNGER TYPE PISTON ASSEMBLY AND TO ALTER THE UPPER LIMIT OF THE STROKE THEREOF, SAID ADJUSTABLE BUSHING IN CONJUNCTION WITH SAID STOP MEANS AND SAID SCALE PROVIDING MEANS FOR PREDETERMINING THE STROKE OF SAID PLUNGER TYPE PISTON ASSEMBLY.