Piston pump and driver therefor
First Claim
1. A disposable pump cartridge for use in a system including a pump drive mechanism, whereby the pump drive mechanism includes a reciprocating drive shaft that operates with a first movement and a second rearward movement, said disposable pump cartridge comprising:
- at least one barrel having an inlet valve and outlet valve associated therewith at a from end of said barrel;
a retention mechanism positioned in said barrel that defines an operational portion and non-operational portion of said barrel, wherein said retention mechanism has a first axial distance from said front end of said barrel defining said non-operational portion;
a piston movable within said barrel from a non-operational position to a first operational position and a second operational position, said piston including a piston coupling mechanism having a first coupler adapted for moving the piston from its non-operational position, and a second coupler adapted to preclude the piston from returning to said nonoperational position during operation;
wherein said retention mechanism releasably maintains the piston in the non-operational position;
a reciprocating shaft coupling mechanism that engages said first coupler of said piston coupling mechanism during said first movement, wherein said piston coupling mechanism has a from wall and said reciprocating shaft coupling mechanism has a second axial distance from said front wall that is greater than or equal to said first axial distance during said first movement;
wherein said piston moves to a second operational position during said second movement of said reciprocating shaft; and
said reciprocating shaft coupling mechanism engages said second coupler of said piston shaft coupling mechanism during subsequent movement of said reciprocating drive shaft thereby precluding movement of said piston within said non-operational portion of said barrel.
2 Assignments
0 Petitions
Accused Products
Abstract
A pump driver, a disposable pump cartridge for use with the pump driver and a beverage dispenser employing the pump drive are disclosed. The disposable pump cartridge comprises at least one barrel 20 having an inlet valve 24 and an outlet valve 26 associated therewith. A piston 28 movable within the barrel 20 is retained in a minimum volume position during transit by a protrusion 22 on the internal surface of the barrel 20. The piston 20 has a piston shaft 28 with a hollow end arranged, in use, to releasably engage a piston driver to drive the piston 28 from its minimum volume position to an operative position, and to reciprocate the piston 28 within the barrel 20 in its operative position to draw fluid into and pump fluid from the barrel 20 via the inlet valve 24 and outlet valve 26 respectively. Methods of engaging, disengaging and changing the disposable pump cartridge are also disclosed.
30 Citations
7 Claims
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1. A disposable pump cartridge for use in a system including a pump drive mechanism, whereby the pump drive mechanism includes a reciprocating drive shaft that operates with a first movement and a second rearward movement, said disposable pump cartridge comprising:
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at least one barrel having an inlet valve and outlet valve associated therewith at a from end of said barrel; a retention mechanism positioned in said barrel that defines an operational portion and non-operational portion of said barrel, wherein said retention mechanism has a first axial distance from said front end of said barrel defining said non-operational portion; a piston movable within said barrel from a non-operational position to a first operational position and a second operational position, said piston including a piston coupling mechanism having a first coupler adapted for moving the piston from its non-operational position, and a second coupler adapted to preclude the piston from returning to said nonoperational position during operation;
wherein said retention mechanism releasably maintains the piston in the non-operational position;a reciprocating shaft coupling mechanism that engages said first coupler of said piston coupling mechanism during said first movement, wherein said piston coupling mechanism has a from wall and said reciprocating shaft coupling mechanism has a second axial distance from said front wall that is greater than or equal to said first axial distance during said first movement; wherein said piston moves to a second operational position during said second movement of said reciprocating shaft; and
said reciprocating shaft coupling mechanism engages said second coupler of said piston shaft coupling mechanism during subsequent movement of said reciprocating drive shaft thereby precluding movement of said piston within said non-operational portion of said barrel. - View Dependent Claims (2, 3, 4)
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5. A pump device comprising:
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a drive mechanism having at least a first protrusion and a second protrusion, the drive mechanism being configured to reciprocate between a first position and a second position, and a disposable pump cartridge, the disposable pump cartridge further comprising; at least one barrel having an inlet valve and outlet valve associated therewith at a front end of said barrel; a retention mechanism positioned in said barrel that defines an operational portion and a non-operational portion of said barrel, wherein said retention mechanism has a first axial distance from said front end of said barrel defining said non-operational portion; a piston movable within said barrel from a non-operational position to it first operational position and a second operational position; and a piston shaft attached to said piston and having a hollow end with a tapered entrance, the tapered entrance being aligned to receive the first protrusion and the second protrusion of the drive mechanism, wherein said first protrusion engages said piston shaft when said drive mechanism has reciprocated to said first position, said piston shaft has a front wall, and said first protrusion has a second axial distance from said front wall that is greater than or equal to said first axial distance when said drive mechanism has reciprocated to said first position; wherein the space between the first protrusion and the second protrusion of the drive mechanism is sufficient to position the piston on the non-operational side of the retention mechanism when the piston shaft is engaged with only the first protrusion and on the operational side of the retention mechanism when the piston shaft is engaged with the second protrusion. - View Dependent Claims (6, 7)
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Specification