US 11,813,606 B2
Dual resolution liquid handling
Henry Donald Schwartz, Manchester, MA (US)
Filed by Henry Donald Schwartz, Manchester, MA (US)
Filed on Sep. 9, 2022, as Appl. No. 17/942,105.
Application 17/942,105 is a division of application No. 16/103,869, filed on Aug. 14, 2018, granted, now 11,491,477.
Prior Publication US 2023/0110014 A1, Apr. 13, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. B01L 3/02 (2006.01)
CPC B01L 3/0217 (2013.01) [B01L 3/0275 (2013.01); B01L 3/0279 (2013.01); B01L 2200/0684 (2013.01); B01L 2200/0689 (2013.01); B01L 2300/0609 (2013.01); B01L 2400/02 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A mechanism for accurately and reliably metering of liquid volumes comprising:
a cylinder holding a dimensionally variable seal at each end that defines a chamber and takes into the chamber a downwardly tapered piston from above, the downwardly tapered piston having a varying diameter, and wherein the greatest diameter being at the top of the downwardly tapered piston, and a tube from below, the tube having a diameter, the greatest diameter of the downwardly tapered piston being less than the diameter of the tube, and the cylinder, downwardly tapered piston and tube being concentric and coaxial to each other,
the seal being thick and compliant enough to maintain a good and stable seal against the tube and downwardly tapered piston,
the cylinder configured and arranged to slidably move up over said downwardly tapered piston and tube to release a portion of the tube from the cylinder while taking in an additional similar portion of the downwardly tapered piston, thereby increasing a volume of air in the chamber and to create a negative pressure or vacuum therein,
the cylinder further configured and arranged to slidably move down over the downwardly tapered piston and tube to release a portion of the downwardly tapered piston from the cylinder while taking in an additional similar portion of the tube, thereby reducing the volume of air in the chamber and to create a positive pressure therein,
said downwardly tapered piston configured and arranged to move with the cylinder by a same distance as the cylinder moves, so that the tube moves alone within the cylinder with no offsetting movement of the downwardly tapered piston in the cylinder, thereby causing a change in the volume of air in the chamber.