Self-Cleaning Injection Port for Analytical Applications
First Claim
1. A self-cleaning injection port assembly for use with a liquid chromatography injection valve, comprising:
- an injection port body defining an interior chamber having an upper chamber portion and a lower chamber portion, an entry opening through which an injection needle can be inserted into the interior chamber, a wash port connected to the upper chamber between the entry opening and the lower chamber portion, and an outlet communicating with the lower chamber portion, the lower chamber portion having associated therewith a needle sealing surface surrounding a portion of the lower chamber portion for effecting a seal with the injection needle when inserted into the interior chamber, and the upper chamber portion having, at least in the region thereof located between the wash port and the entry opening, a cross-sectional size greater than a cross-sectional area bounded by the needle sealing surface whereby in such region the injection needle, when inserted therein, will be spaced from the interior wall of the upper chamber to preclude the transfer of any foreign material clinging to the exterior surface of the needle from touching the interior wall of the upper chamber; and
a washing device movable between a first position allowing an injection needle to be inserted through the entry opening into the interior chamber of the injection port body and into sealing engagement with the needle sealing surface, and a second position closing the entry opening of the chamber after the injection needle has been withdrawn from the interior chamber, whereby a wash fluid may be passed through the wash port, upper chamber, lower chamber and outlet for cleaning.
1 Assignment
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Accused Products
Abstract
A self-cleaning injection port assembly that uses a movable wash chamber closure device (26) for opening and closing an injection needle entry passage (34) of an injection port wash chamber. For sample injection, the wash chamber closure device (26) can be moved clear of the path along which the injection needle passes through the wash chamber into the injection port, thereby enabling insertion of the injection needle into the injection port. For washing, the wash chamber closure device (26) is moved to a position closing the entry passage (34) of the injection port wash, after which cleaning fluid may be circulated through the injection port for cleaning.
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Citations
12 Claims
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1. A self-cleaning injection port assembly for use with a liquid chromatography injection valve, comprising:
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an injection port body defining an interior chamber having an upper chamber portion and a lower chamber portion, an entry opening through which an injection needle can be inserted into the interior chamber, a wash port connected to the upper chamber between the entry opening and the lower chamber portion, and an outlet communicating with the lower chamber portion, the lower chamber portion having associated therewith a needle sealing surface surrounding a portion of the lower chamber portion for effecting a seal with the injection needle when inserted into the interior chamber, and the upper chamber portion having, at least in the region thereof located between the wash port and the entry opening, a cross-sectional size greater than a cross-sectional area bounded by the needle sealing surface whereby in such region the injection needle, when inserted therein, will be spaced from the interior wall of the upper chamber to preclude the transfer of any foreign material clinging to the exterior surface of the needle from touching the interior wall of the upper chamber; and a washing device movable between a first position allowing an injection needle to be inserted through the entry opening into the interior chamber of the injection port body and into sealing engagement with the needle sealing surface, and a second position closing the entry opening of the chamber after the injection needle has been withdrawn from the interior chamber, whereby a wash fluid may be passed through the wash port, upper chamber, lower chamber and outlet for cleaning. - View Dependent Claims (2, 3, 4, 5, 6, 10)
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- 7. A self-cleaning injection port assembly for use with a liquid chromatography injection valve, comprising an injection port body including an interior wash chamber having an entry opening for insertion of an injection needle therethrough, and a washing device movable between a first position allowing the injection needle to be inserted through the entry opening into the interior chamber of the injection port body and a second position closing the entry opening of the chamber after the injection needle has been withdrawn from the interior chamber for cleaning.
- 11. A method of cleaning an injection port assembly, wherein the injection port assembly includes an injection port body having an interior wash chamber with an entry opening for insertion of an injection needle therethrough, the method comprising the steps of moving a washing device from a first position allowing the injection needle to be inserted through the entry opening into the interior chamber of the injection port body to a second position closing the entry opening of the chamber after the injection needle has been withdrawn from the interior chamber, and causing cleaning fluid to flow through the interior chamber when the washing device is in the second position closing the entry opening.
Specification