Outer Bore Pump

Abstract

An improved piston pump assembly including a liquid pump having a variable volume liquid compartment and an air pump having a variable volume air compartment in which the pump assembly is secured to the neck of a bottle to the inner chamber-forming part of the fluid compartment inside a neck of a container and an air compartment for the air pump defined within an air chamber having a diameter greater than a diameter of the neck of the bottle and located external of the neck.

We claim: 
     
         1 . A pump assembly comprising:
 a liquid pump for drawing liquid from a reservoir and discharging the liquid and an air pump for drawing air from the atmospheric and discharging the air,   the pump assembly comprising:   a piston chamber-forming member having an inner cylindrical chamber and an outer cylindrical chamber, each having a diameter, a chamber wall, an inner end and an outer end;   the diameter of the inner chamber being less than the diameter of the outer chamber,   
       the inner chamber and outer chamber being coaxial with the inner chamber axially inwardly of the outer chamber;
 the inner end of the inner chamber in fluid communication with the reservoir; 
 a piston-forming element received in the piston chamber-forming member axially slidable inwardly and outwardly therein between an outward extended position and an inward retracted position; 
 in a cycle of operation, the piston-forming element moving relative the piston chamber-forming member between the extended position and the retracted position in a retraction stroke and between the retracted position and the extended position in a withdrawal stroke, 
 the piston-forming element having an axially extending hollow stem having a central passageway closed at an inner end and having an outlet proximate an outer end; 
 an inner disc on the stem extending radially outwardly from the stem into engagement with the chamber wall of the inner chamber to restrict fluid flow inwardly therebetween; 
 an outer disc on the stem spaced axially outwardly from the inner disc and extending radially outwardly from the stem into engagement with the chamber wall of the outer chamber to restrict flow outwardly therebetween; 
 an inlet passage located on the stem between the outer disc and the inner disc in communication with the passageway providing for flow radially through the wall of the stem; 
 the fluid pump formed by the interaction of the piston-forming element and the piston chamber-forming member with the fluid pump including an annular fluid compartment formed outwardly of the inner disc within the inner chamber with a volume of the fluid compartment increasing in one of the extension stroke and the retraction stroke and decreasing in a different, other of these strokes whereby in a cycle of operation, the fluid pump draws fluid from the reservoir into the fluid compartment and discharges fluid from the fluid compartment to pass via the inlet passage to the outlet; 
 the air pump formed by the interaction of the piston-forming element and the piston chamber-forming member with the air pump including an annular air compartment formed inwardly of the outer disc within the outer chamber with a volume of the air compartment increasing in a first of the extension stroke and the retraction stroke and decreasing in a different second of these strokes whereby in a cycle of operation, the air pump draws air from the atmosphere into the air compartment and discharges air from the air compartment, 
 the reservoir having an annular neck extending outwardly to an outer end providing a reservoir opening into the reservoir; 
 the piston chamber-forming member secured to the neck of the reservoir with the inner cylindrical chamber radially inwardly of the neck with the inner end of the inner chamber axially inwardly of the reservoir opening, 
 the neck having an internal neck diameter, 
 the diameter of the outer chamber being greater than the diameter of the neck. 
 
     
     
         2 . A pump as claimed in  claim 1  wherein:
 the piston chamber-forming member further including an intermediate chamber axially between the inner cylindrical chamber and the outer cylindrical chamber, 
 the intermediate chamber having a diameter, a chamber wall, an inner end and an outer end; 
 the intermediate chamber coaxial with both of the inner cylindrical chamber and the outer cylindrical chamber, 
 the outer end of the inner chamber opening into the inner end of the intermediate chamber; 
 the outer end of the intermediate chamber opening into the inner end of the outer chamber; 
 an intermediate disc on the stem extending radially outwardly from the stem adapted to engage the chamber wall of the inner chamber to resist fluid flow inwardly therepast, 
 the intermediate disc spaced axially outwardly from the inner disc and spaced axially inwardly from the outer disc, 
 the inlet passage located on the stem between the outer disc and the intermediate disc; 
 the diameter of the intermediate chamber being different than the diameter of the inner chamber. 
 
     
     
         3 . A pump as claimed in  claim 2  wherein the fluid compartment defined within the inner chamber and the intermediate chamber between the inner disc and the intermediate disc, and
 the air compartment defined within the outer chamber and the intermediate chamber between the outer disc and the intermediate disc. 
 
     
     
         4 . A pump as claimed in  claim 3  wherein the diameter of the intermediate chamber is less than the diameter of the inner chamber. 
     
     
         5 . A pump as claimed in  claim 3  wherein the diameter of the intermediate chamber is greater than the diameter of the inner chamber. 
     
     
         6 . A pump as claimed in  claim 1  wherein:
 the piston chamber-forming member carrying an annular flange coaxially about the inner cylindrical chamber spaced radially from the inner cylindrical chamber, and 
 the piston chamber-forming member secured to the neck of the reservoir with the annular flange radially outwardly of the neck. 
 
     
     
         7 . A pump as claimed in  claim 3  wherein, in a retraction stroke, on axial movement of the piston-forming element from the retracted position to the extended position, air is drawn into the air compartment from the outlet and, in the extension stroke, both air and fluid are forced through the inlet passage to the passageway and out the outlet. 
     
     
         8 . A pump as claimed in  claim 7  including a porous member in the passageway between the first inlet and the outlet for generating turbulence in fluid passing therethrough to generate foam when air and liquid pass therethrough simultaneously. 
     
     
         9 . A pump as claimed in  claim 3  in which the inner chamber is disposed above the outer chamber with the inner end of the inner chamber above the outer end of the inner chamber and the inner end of the outer chamber above the outer end of the outer chamber. 
     
     
         10 . A pump as claimed in  claim 8  in which the inner chamber is disposed above the outer chamber with the inner end of the inner chamber above the outer end of the inner chamber and the inner end of the outer chamber above the outer end of the outer chamber. 
     
     
         11 . A pump as claimed in  claim 5  wherein, in a retraction stroke, on axial movement of the piston-forming element from the retracted position to the extended position, fluid is drawn into the fluid compartment from the reservoir and, in the extension stroke, fluid forced past the intermediate disc into the air compartment and then through the inlet passage to the passageway and out the outlet. 
     
     
         12 . A pump as claimed in  claim 4  wherein, in a withdrawal stroke, on axial movement of the piston-forming element from the retracted position to the extended position, fluid is drawn into the fluid compartment from the reservoir and, in the retraction stroke, fluid is forced past the intermediate disc into the air compartment and then through the inlet passage to the passageway and out the outlet. 
     
     
         13 . A pump for dispensing liquid from a reservoir comprising:
 a piston chamber-forming member having an inner cylindrical chamber and an outer cylindrical chamber, each having a diameter, a chamber wall, an inner end and an outer end;   the diameter of the inner chamber being less 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 outer chamber;   an inner end of the inner chamber in fluid communication with the reservoir;   a piston-forming element received in the piston chamber-forming member axially slidable inwardly and outwardly therein between an outward extended position and an inward retracted position;   the piston-forming element having an axially extending hollow stem having a central passageway closed at an inner end and having an outlet proximate an outer end;   an inner disc on the stem extending radially outwardly from the stem adapted to engage to the chamber wall of the inner chamber;   an intermediate disc on the stem extending radially outwardly from the stem adapted to engage the chamber wall of the inner chamber, the intermediate disc spaced axially outwardly from the inner disc relative the inner end of the stem;   an outer disc on the stem spaced axially outwardly from the intermediate disc and extending radially outwardly from the stem into engagement with the chamber wall of the outer chamber to prevent fluid flow outwardly therebetween;   a first inlet located on the stem between the outer disc and the intermediate disc in communication with the passageway;   in the retracted position, the intermediate disc is received in the inner chamber to prevent fluid flow from the outer end of the inner chamber outwardly therepast and the inner disc does not prevent fluid flow between the reservoir and the inner chamber therepast via the inner end of the inner chamber;   in the extended position, the inner disc is received in the inner chamber to prevent fluid flow from the inner end of the inner chamber inwardly therepast and the intermediate disc does not prevent fluid flow between the inner chamber and the outer chamber via the outer end of the inner chamber,   the reservoir having an annular neck extending outwardly to an outer end providing a reservoir opening into the reservoir;   the piston chamber-forming member secured to the neck of the reservoir with the inner cylindrical chamber radially inwardly of the neck with the inner end of the inner chamber axially inwardly of the reservoir opening,   the neck having an internal neck diameter,   the diameter of the outer chamber being greater than the diameter of the neck.   
     
     
         14 . A pump as claimed in  claim 1  wherein:
 the piston chamber-forming member carrying an annular flange coaxially about the inner cylindrical chamber spaced radially from the inner cylindrical chamber, and 
 the piston chamber-forming member secured to the neck of the reservoir with the annular flange radially outwardly of the neck.