Rotary plunger pump subsystems

Patent metadata

Field	Value
Publication number	US-11344669-B2
Application number	US-202017259640-A
Country	US
Kind code	B2
Filing date	Aug 21, 2020
Priority date	Aug 26, 2019
Publication date	May 31, 2022
Grant date	May 31, 2022

Abstract

A rotary sub-assembly for pumping of fluid is provided. The sub-assembly includes a hollow body defining a cavity having a longitudinal axis, the body comprising a cavity wall with at least two ports passing therethrough. At least a portion of the cavity has a non-circular cross-section such that a first constant or varying radial distance from the longitudinal axis to inwardly-offset segments of the cavity wall surrounding the two ports is less than a second constant or varying radial distance from the longitudinal axis to second segments of the cavity wall spaced apart from the two ports. A rotatable plunger is housed in the cavity. The plunger is sized and shaped such that a side wall of the plunger can establish a liquid-tight seal against the inwardly-offset segments of the cavity wall, but does not establish a liquid-tight seal with the second segments of the cavity wall spaced apart from the two ports.

First claim

What is claimed is:

1. A rotary sub-assembly for pumping of drug fluid in a drug-delivery device, said sub-assembly comprising:
a hollow body comprising a housing side wall defining a cavity extending about a longitudinal axis between a closed distal end and an open proximal end, the housing side wall including at least two ports passing therethrough and in fluid communication with the cavity, wherein at least a working portion of the cavity has a non-circular cross-section extending along a plane perpendicular to the longitudinal axis, the working portion being defined by first inwardly-offset segments of the housing side wall interconnected by second segments of the housing side wall, the first inwardly-offset segments spaced from the longitudinal axis by a constant or varying first radial distance, and the second segments spaced from the longitudinal axis by a constant or varying second radial distance that is greater than the first radial distance, wherein said first inwardly-offset segments of the housing side wall are disposed along regions of the side wall surrounding the two ports, and said second segments of the housing side wall are spaced apart from the two ports; and
a plunger housed in the cavity defining a working chamber between the plunger and the housing side wall, wherein:
the plunger is configured to rotate relative to the body in order to put the working chamber into sequential fluid-flow communication with at least one port of the two ports, then no port, then at least the other of said two ports,
the plunger is further configured to move in longitudinal translation relative to the body and thereby cause a volume of said working chamber to vary in order to successively take in a drug fluid from one of the two ports and then to discharge the fluid from the other of the two ports, and
the plunger is sized and shaped such that when the working chamber is in fluid-flow communication with one of the two ports, a side wall of the plunger establishes a liquid-tight seal against the first inwardly-offset segment of the housing side wall surrounding the other port of the two ports, but does not establish a liquid-tight seal with the second segments of the housing side wall.

2. The rotary sub-assembly of claim 1 , wherein the plunger further comprises a plunger pin extending radially outward from the plunger.

3. The rotary sub-assembly of claim 2 , wherein the body further comprises a first pumping track configured to slidably contact a distal side of the plunger pin as the plunger rotates relative to the body, wherein the pumping track comprises at least one flat section extending along a plane that is perpendicular to the longitudinal axis.

4. The rotary sub-assembly of claim 3 , wherein the pumping track comprises both a distal flat section extending along a plane that is perpendicular to the longitudinal axis and a proximal flat section extending along a different plane that is perpendicular to the longitudinal axis.

5. The rotary sub-assembly of claim 2 , wherein the body further comprises a first pumping track configured to slidably contact a distal side of the plunger pin, and a second pumping track configured to slidably contact a proximal side of the plunger pin.

6. The rotary sub-assembly of claim 5 , wherein the first pumping track and the second pumping track each comprise at least one flat section extending along a plane that is perpendicular to the longitudinal axis.

7. The rotary sub-assembly of claim 1 , wherein:
a portion of the cavity has a circular cross-section along a plane perpendicular to the longitudinal axis,
the plunger further comprises a proximal annular sealing rib and a distal annular sealing rib longitudinally spaced from one another, wherein both annular sealing ribs contact a portion of the housing side wall defining the portion of the cavity having the circular cross-section so as to establish a liquid-tight seal that seals the working chamber from the open proximal end of the cavity.

8. The rotary sub-assembly of claim 7 , wherein:
the plunger is configured to move in longitudinal translation relative to the body between a proximal plunger position and a distal plunger position; and
both annular sealing ribs on the plunger are located proximal to the two ports opening out into the cavity when the plunger is in its distal plunger position.

9. The rotary sub-assembly of claim 8 , wherein a longitudinal distance between the two annular sealing ribs is no less than a longitudinal distance between the proximal plunger position and the distal plunger position.

10. The rotary sub-assembly of claim 1 , wherein each of the first inwardly-offset segments of the housing side wall comprises a first edge that transitions smoothly to a first neighboring edge of said second segments of the housing side wall, and a second edge that transitions abruptly to a second neighboring edge of said second segments of the housing side wall.

11. A drug-delivery device comprising:
a drug reservoir storing a drug fluid; and
the rotary sub-assembly of claim 1 for pumping the drug fluid from the drug reservoir for delivery to a patient.

Assignees

• Lilly Co Eli

Inventors

• Agard Ryan Michael
• Clemente Matthew James
• Devitt Shaun Robert

Classifications

• F04B2201/02011

  Angular position of a piston rotating around its own axis · CPC title

• F04B7/06

  the pistons and cylinders being relatively reciprocated and rotated · CPC title

• A61M2205/106

  reciprocating · CPC title

• A61M2205/103

  rotating · CPC title

• A61M5/14216 Primary

  Reciprocating piston type · CPC title