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US 7,790,117 B2Granted
Filter vial
AssigneeScientific Plastic Products, Inc.
InventorsSamuel A. Ellis, Kishan G. Hingorani
Life of this patent
Estimating the term…
Abstract
A filter vial and piston are provided where the vial has a cylindrical wall with a closed bottom and open top and with the hollow, tubular piston therein. The piston has a distal end covered by a cup having a proximal cup seal extending outward to engage the walls of the vial to form a fluid tight seal with the vial during use. The distal end of the piston has a piston flange extending outwardly and located adjacent a recess in the piston so the cup forms a snap fit over the piston flange and extends into the recess. The piston flange causes the cup to bulge sufficiently outward to form a fluid tight seal with the vial during use. A filter is placed in the bottom of the cup.
Claims27
A filter vial apparatus having a longitudinal axis, comprising:
- a tubular vial having a closed bottom, an open top and walls defining a cylindrical interior with a diameter D;
- a tubular piston with opposing distal and proximal ends with at least the distal end being open, the piston having walls defining a cylindrical interior with an exterior facing recessed portion adjacent the distal end the piston, the piston further having a distal piston flange at or adjacent to the distal end of the piston and extending outward from the piston;
- a filter support located inside the piston at the distal end of the piston;
- a retainer cup having a continuous sidewall extending between a proximal and distal end of the cup with an interior diameter smaller than the distal piston flange and having a lip extending inward toward the longitudinal axis at the distal end of the retainer cup, the retainer cup further having a cup seal extending outward from the proximal end of the cup a distance greater than the diameter D, the sidewall of the cup being sufficiently flexible to deform outward as the cup passes over the distal piston flange to assume an outer dimension larger than diameter D at the location of the piston flange when the retainer cup passes over the distal piston flange;
- and
- a filter interposed between the retaining cup's lip and the distal end of the piston when the proximal end of the retainer cup is placed over the distal end of the piston.
3 more elements
A filter vial assembly, comprising:
- a cylindrical walled vial with a closed bottom and open top having a hollow, tubular piston therein, the piston having a distal end covered by a cup having a proximal cup seal engaging the walls of the vial to form a fluid tight seal when the piston is advanced into the vial a distance sufficient to engage the proximal cup seal with the vial walls, the distal end of the piston having a piston flange extending outwardly and located adjacent a recess in the piston so the cup forms a snap fit over the piston flange and extends into the recess, the piston flange causing flexible walls of the cup to bulge sufficiently outward to form a distal fluid tight cup seal with the vial when the flange and cup are inserted into the vial;
- and
- a filter having a periphery abutting an inwardly extending lip on the cup and held between a piston support at the distal end of the piston and the lip.
A method of forming a piston for a filter vial, the piston having a cylindrical tube with opposing proximal and distal ends, comprising:
- forming an outwardly extending piston flange at the distal end of the piston;
- forming a cylindrical recess around a periphery of the distal end of the piston at the distal end of the piston and adjacent to the piston flange and on the proximal side of the piston flange;
- placing a filter in the bottom of a retaining cup which cup is sized to fit over the distal end of the piston, the retaining cup having an open proximal end and an inward extending lip at an opposing distal end which lip abuts a periphery of the filter;
- placing the open proximal end of the cup over the distal end of the piston and piston flange to form a snap fit between the proximal end of the cup and the recess on the piston and advancing the retaining cup along the piston until the distal end of the piston abuts the filter, the retaining cup having an outwardly extending seal at the proximal end sized to sealingly engage the inside of the filter vial during use, the retaining cup being made of sufficiently flexible material to bulge outward at the piston flange with the piston flange and retaining cup being dimensioned to extend outward a distance sufficient to form a fluid tight seal with walls of the filter vial during use.
1 more element
A filter vial apparatus having a longitudinal axis, comprising:
- a tubular vial having a closed bottom, an open top and walls defining a cylindrical interior with a diameter D extending between the top and bottom;
- a tubular piston with opposing distal and proximal ends with at least the distal end being open, the piston having walls defining a cylindrical interior, the piston further having a distal piston flange at the distal end of the piston and extending outward from the piston;
- a filter support located inside the piston at the distal end of the piston;
- a retainer cup having a cylindrical sidewall extending between a proximal end and distal end of the cup, the cup having an interior diameter smaller than the distal piston flange, the sidewall of the cup being sufficiently flexible to deform outward as the cup passes over the distal piston flange to assume an outer dimension larger than diameter D at the location of the piston flange when the retainer cup passes over the distal piston flange, the retainer cup further having a cup seal extending outward from the proximal end of the cup a distance sufficient to seal against the vial wall when the distal piston flange is inserted into the cup and causes said outward deformation of the cup sidewall, the cup having an opening in the distal end;
- and
- a filter covering the opening in the distal end of the cup.
3 more elements
A filter vial assembly, comprising:
- a cylindrical walled vial with a closed bottom and open top having an inner diameter D between its top and bottom, the vial having a hollow, tubular piston therein, the piston having a distal end covered by a cup having a proximal cup seal engaging the walls of the vial to form a fluid tight seal when the piston is advanced into the vial a distance sufficient to engage the proximal cup seal with the vial walls, the distal end of the piston having a piston flange extending outwardly and causing the flexible walls of the cup to bulge sufficiently outward to form a distal fluid tight seal with the vial when the flange and cup are inserted into the vial;
- and
- a filter in a distal end of the cup located to cover an opening in the distal end of the cup through which fluid flows during use of the assembly.
A method of forming a piston for a filter vial, the piston having a cylindrical tube with opposing proximal and distal ends, comprising:
- forming an outwardly extending piston flange at the distal end of the piston;
- forming a cylindrical recess around a periphery of the distal end of the piston at the distal end of the piston and adjacent to the piston flange and on the proximal side of the piston flange;
- placing a filter in the bottom of a retaining cup which cup is sized to fit over the distal end of the piston, the retaining cup having an open proximal end and an opposing distal end with an opening in the distal end, the filter covering the opening;
- placing the open proximal end of the cup over the distal end of the piston and piston flange to form a snap fit between the proximal end of the cup and the recess on the piston and advancing the retaining cup along the piston until the distal end of the piston abuts the filter, the retaining cup having an outwardly extending seal at the proximal end sized to sealingly engage the inside of the filter vial during use, the retaining cup having a sufficiently flexible side so that the side bulges outward at the location of the piston flange with the piston flange and retaining cup being dimensioned so the cup side bulges outward a distance sufficient to form a fluid tight seal with walls of the filter vial at the location of the piston flange during use.
1 more element
A piston for a filter vial, the piston having a cylindrical tube with opposing proximal and distal ends, comprising:
- an outwardly extending piston flange at the distal end of the piston;
- a cylindrical recess around a periphery of the distal end of the piston at the distal end of the piston and adjacent to the piston flange and on the proximal side of the piston flange;
- a retaining cup having an open proximal end which is sized to fit over the distal end of the piston, the retaining cup having a distal end opposite the proximal end with an opening in the distal end, and a continuous side extending between the proximal and distal ends of the cup, the open proximal end of the cup extending over and past the distal end of the piston and piston flange to form a snap fit between the proximal end of the cup and the recess on the piston, the retaining cup having an outwardly extending cup seal at the proximal end, the cup seal being sized to sealingly engage the inside of the filter vial during use, the side of the retaining cup being sufficiently flexible so that the side bulges outward at the location of the piston flange with the piston flange and retaining cup being dimensioned so the cup side bulges outward a distance sufficient to form a fluid tight seal with walls of the filter vial during use.
Dependencies are inferred from the claim text.