Method for filtering liquid using a filter vial
AssigneeScientific Plastic Products, Inc.
InventorsSamuel A. Ellis, Kishan G. Hingorani
Life of this patent
Estimating the term…
Abstract
An apparatus filters particles from small volumes of liquid in a tubular vial having an open top and closed bottom with a tubular plunger sliding in the vial to force liquid through a filter at the end of the plunger and into a cavity in the plunger. The filter is held by a cap placed over the end of the plunger. The vial's bottom has an upward extending protrusion mating with a conforming recess in the cap to direct liquid to the protraction and filter as the cap abuts the bottom of the vial. Channels in the bottom help direct liquid flow.
Claims21
A tubular plunger assembly for filtering liquids, comprising:
- a tubular plunger assembly having a cylindrical body extending along a longitudinal axis to enclose a liquid cavity in the plunger, the plunger assembly having a bottom end with a shaped cavity in liquid communication with the liquid cavity, the shaped cavity having a wall inclined away from the bottom end and toward the longitudinal axis, the bottom end configured to block the passage of liquid except through the shaped cavity, the plunger assembly having at least one piston seal encircling the longitudinal axis and an outer circumference of the plunger assembly, the piston seal located adjacent the bottom end of the piston assembly;
- a filter connected to the plunger assembly and interposed between the shaped cavity and the liquid cavity in the plunger and connected to the plunger assembly to filter all liquid passing through the shaped cavity and into the liquid cavity of the plunger;
- and
- wherein the plunger has a cross section orthogonal to the longitudinal axis that is circular.
Dependencies are inferred from the claim text.