Self-lubricating piston for pharmaceutical container
First Claim
1. A piston for a pharmaceutical container comprising:
- a container having an open end, a closed end, and a wall structure having an inner surface, the container having a longitudinal axis;
a seal member having an upper side, comprising a compressible material, and being at least partially positioned within the container between the open end and closed end, the seal member also having an outer periphery and means for retaining a lubricant, the outer periphery being dimensioned to provide sealing engagement with said inner surface of said wall structure;
a lubricant contained within said means for retaining a lubricant; and
means for exerting a longitudinally-directed force on the seal member and at least partially compressing the seal member in the direction of the longitudinal axis, said exerting means compressing said retaining means and forcing said lubricant from said retaining means and into contact with said inner surface of said container when said seal member is at least partially compressed in the direction of the longitudinal axis.
1 Assignment
0 Petitions
Accused Products
Abstract
A compressible seal member is provided with peripherally distributed and axially spaced lubricant retaining grooves, or with radially extending lubricant channels in communication with a central lubricant reservoir. The sealing member has land portions and groove portions on the outer periphery, with the lubricant grooves or channels located along the groove portions. The seal member is installed within a pharmaceutical container with the tool having a working end received within a central aperture formed in the seal member so that the insertion forced is applied near the bottom end of the seal member to prevent compression during installation. When the pharmaceutical is expelled from the container, a plunger pushes on the accessible end of the seal member to compress the seal member axially and force the lubricant out of the grooves or channels and into contact with the inner wall surfaces of the container. The seal member provides a good friction fit during storage of the container to prevent leakage of the pharmaceutical and provides low sliding friction to permit smooth translatory motion of the seal member during expulsion of the pharmaceutical.
39 Citations
11 Claims
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1. A piston for a pharmaceutical container comprising:
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a container having an open end, a closed end, and a wall structure having an inner surface, the container having a longitudinal axis; a seal member having an upper side, comprising a compressible material, and being at least partially positioned within the container between the open end and closed end, the seal member also having an outer periphery and means for retaining a lubricant, the outer periphery being dimensioned to provide sealing engagement with said inner surface of said wall structure; a lubricant contained within said means for retaining a lubricant; and means for exerting a longitudinally-directed force on the seal member and at least partially compressing the seal member in the direction of the longitudinal axis, said exerting means compressing said retaining means and forcing said lubricant from said retaining means and into contact with said inner surface of said container when said seal member is at least partially compressed in the direction of the longitudinal axis. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A piston for a pharmaceutical container comprising:
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a container having an open end, a closed end, and a wall structure having an inner surface; a seal member positioned within the container, comprising; means for retaining a lubricant, an outer periphery dimensioned to provide sealing engagement with said inner surface of said wall structure, a lubricant reservoir in fluid communication with ambient, a plurality of lubricant channels fluidly coupled to the lubricant reservoir, the lubricant channels extending between said lubricant reservoir and said outer periphery; and a plunger configured to drivingly engage the seal member, the plunger including means for displacing a lubricant introduced into the lubricant reservoir so that said lubricant is forced through said plurality of lubricant channels and into contact with said inner surface of said container. - View Dependent Claims (8, 9, 10, 11)
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Specification