Fluid reservoir piston
First Claim
1. An apparatus for dispensing a medication fluid comprising:
- a reservoir adapted to contain the fluid and adapted for use with a drive system having a threaded linear actuation member; and
a piston comprising;
a first member adapted to be slidably mounted within the reservoir and adapted to form at least part of a fluid-tight barrier within the reservoir;
the first member having an external proximate side and an external distal side, the external proximate side being adapted to contact the fluid and being made of a material having a first stiffness, and wherein the external distal side forms an opening leading to a cavity and includes threads adapted to releasably engaged the threaded linear actuation member;
a second member having a first side and a second side, at least a portion of the second member being disposed within the cavity of the first member; and
the first side of the second member being in the cavity and adjacent to the external proximate side of the first member and being made of a material having a stiffness which is greater than the first stiffness; and
the second member further including one or more passages through the second member from the first side to the second side of the second member to permit admittance of a sterilization agent to the first side of the second member.
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Accused Products
Abstract
An improved pump, reservoir and reservoir piston are provided for controlled delivery of fluids. A motor is operably coupled to a drive member, such as a drive screw, which is adapted to advance a plunger slide in response to operation of the motor. The plunger slide is removably coupled to the piston. The piston comprises a first member and a second member. The first member has an external proximate side and an external distal side. The external proximate side is adapted to contact the fluid and is made of a material having a first stiffness. The second member has a first side and a second side and is at least partially disposed within the first member. The first side of the second member is adjacent to the external proximate side of the first member and is made of a material having a stiffness which is greater than the first stiffness.
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Citations
39 Claims
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1. An apparatus for dispensing a medication fluid comprising:
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a reservoir adapted to contain the fluid and adapted for use with a drive system having a threaded linear actuation member; and
a piston comprising;
a first member adapted to be slidably mounted within the reservoir and adapted to form at least part of a fluid-tight barrier within the reservoir;
the first member having an external proximate side and an external distal side, the external proximate side being adapted to contact the fluid and being made of a material having a first stiffness, and wherein the external distal side forms an opening leading to a cavity and includes threads adapted to releasably engaged the threaded linear actuation member;
a second member having a first side and a second side, at least a portion of the second member being disposed within the cavity of the first member; and
the first side of the second member being in the cavity and adjacent to the external proximate side of the first member and being made of a material having a stiffness which is greater than the first stiffness; and
the second member further including one or more passages through the second member from the first side to the second side of the second member to permit admittance of a sterilization agent to the first side of the second member. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28)
a first chamber extending from the external distal side into the cavity; and
a second chamber extending from the first chamber to an internal proximate wall, the internal proximate wall being disposed adjacent to the external proximate side;
and wherein the second member is disposed within the second chamber.
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12. The apparatus of claim 11, wherein the first chamber is defined by a generally cylindrically-shaped first wall extending axially from the external distal side into the cavity, and wherein the second chamber is defined by:
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a generally cylindrically-shaped second wall extending axially from the generally cylindrically-shaped first wall into the cavity, the generally cylindrically-shaped second wall having a radius which is greater than that of the generally cylindrically-shaped first wall;
a ledge extending from the generally cylindrically-shaped first wall to the generally cylindrically-shaped second wall; and
the internal proximate wall.
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13. The apparatus of claim 12, wherein the internal proximate wall of the second chamber and the first member external proximate side are in a generally parallel spaced-apart relationship.
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14. The apparatus of claim 13, wherein the internal proximate wall has a generally conical shape and the external proximate side has a generally conical shape.
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15. The apparatus of claim 14, wherein the second member has a generally conical face, a generally cylindrical side wall and a planar back wall, the generally conical face being adapted to mate with the internal proximate wall and the second member being adapted to seat against the ledge.
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16. The apparatus of claim 14, wherein the second member has a conical face portion which terminates in a spherically-shaped end portion.
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17. The apparatus of claim 15, wherein the first member is made of an elastomeric material and the second member is made of one of stainless steel and plastic.
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18. The apparatus of claim 12, wherein the generally cylindrically shaped first wall has threads.
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19. The apparatus of claim 18, wherein the threads have a 2 start, 40 thread per inch pitch.
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20. The apparatus of claim 1, wherein the second member is formed from ceramic.
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21. The apparatus of claim 1, wherein the second member is formed from a plastic material.
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22. The apparatus of claim 1, wherein the second member is formed with ridges on the first side of the second member to permit admittance of a sterilization agent to the first side of the second member.
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23. The apparatus of claim 1, wherein the second member is formed with notches extending from the first side of the second member to the second side of the second member to permit admittance of a sterilization agent to the first side of the second member.
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24. The apparatus of claim 1, wherein the second member formed with channels on the first side of the second member to permit admittance of a sterilization agent to the first side of the second member.
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25. The apparatus of claim 1, wherein the second member is formed with corrugations to permit admittance of a sterilization agent to the first side of the second member.
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26. The apparatus of claim 1, wherein the second member is formed from a porous material to permit admittance of a sterilization agent to the first side of the second member.
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27. The apparatus of claim 1, wherein the second member is formed from woven fiber-like structures to permit admittance of a sterilization agent to the first side of the second member.
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28. The apparatus of claim 1, wherein the second member is formed as a composite of a first material with a second porous material to permit admittance a sterilization agent to the first side of the second member.
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29. A piston for a reservoir adapted to contain fluid and adapted for use with a drive system having a threaded linear actuation member, the piston comprising:
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a first member adapted to be slidably mounted within the reservoir and adapted to form a fluid-tight barrier within the reservoir;
the first member having an external proximate side and an external distal side, the external proximate side being adapted to contact the fluid and being made of a material having a first stiffness, and wherein the external distal side forms an opening leading to a cavity and includes threads adapted to releasably engage the threaded linear actuation member; and
a second member for providing a second stiffness to the external proximate side is positioned in the cavity, the second stiffness being greater than the first stiffness, wherein the second member has a first side and a second side and includes one or more passages through the second member from the first side to the second side of the second member to permit admittance of a sterilization agent to the first side of the second member. - View Dependent Claims (30, 31, 32, 34, 35, 36, 37, 38, 39)
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33. The piston of claimed 29, wherein the second member is formed with ridges on the first side of the second member to permit admittance of a sterilization agent to the first side of the second member.
Specification