Patent ID: 8500416
Filing Date: 2013-08-06
Classification: B05B

Abstract:
1. A pump for dispensing liquid from a source of fluid comprising: a piston chamber-forming member having an inner cylindrical chamber and an outer cylindrical chamber, the inner chamber and outer chamber each having a diameter, a chamber wall, an inner end and an outer end, the diameter of the inner chamber being substantially constant, the diameter of the inner chamber being either the same as or different than the diameter of the outer chamber, the inner chamber and outer chamber being coaxial with the outer end of the inner chamber opening into the inner end of the outer chamber, the inner end of the inner chamber in fluid communication with the source of fluid, a piston-forming element having an inner end and an outer end, the piston-forming element received in the piston chamber-forming member axially slidable inwardly and outwardly therein, said piston forming element having an axially extending stem, an inner disk on the stem, the inner disk extending radially outwardly from the stem to proximate the chamber wall of the inner chamber circumferentially thereabout, a first intermediate disk on the stem spaced axially outwardly from the inner disk and extending radially outwardly from the stem to proximate the chamber wall of the inner chamber circumferentially thereabout, an outer disk on the stem spaced axially outwardly from the first intermediate disk and extending radially outwardly from the stem to proximate the chamber wall of the outer chamber circumferentially thereabout, the stem having a central passageway therethrough from an inlet to an outlet, the inlet located on the stem between the first intermediate disk and the outer disk in communication with the passageway, the outlet located on the stem spaced axially outward of the outer disk proximate the outer end of the piston-forming element, the piston-forming element slidably received in the piston chamber-forming member for reciprocal axial inward and outward movement therein between a retracted position and an extended position in a cycle of operation during which the inner disk is maintained in the inner chamber, the first intermediate disk is maintained in the inner chamber, and the outer disk is maintained in the outer chamber, during each such cycle of operation: (a) the inner disk substantially preventing fluid flow in the inner chamber past the inner disk in an inward direction, (b) the first intermediate disc substantially preventing fluid flow in the inner chamber past the first intermediate disk in an inward direction, (c) the outer disk substantially preventing fluid flow in the outer chamber past the outer disk in an outward direction (d) the inner disk elastically deforming away from the chamber wall of the inner chamber to permit fluid flow in the inner chamber past the inner disk in an outward direction, and (e) the first intermediate disk elastically deforming away from the chamber wall of the inner chamber to permit fluid flow in the inner chamber past the first intermediate disk in an outward direction.