Pipette for use with a pipette tip with an integrated plunger

Patent metadata

Field	Value
Publication number	US-12303883-B2
Application number	US-202117375568-A
Country	US
Kind code	B2
Filing date	Jul 14, 2021
Priority date	Jul 14, 2020
Publication date	May 20, 2025
Grant date	May 20, 2025

Abstract

A pipette comprises a housing extending from a lower end to an upper end and a neck extending from the lower end of the housing and configured to hold a pipette tip. A stroke rod comprising an upper end and a lower end is configured to displace a tip plunger in the pipette tip. A drive apparatus is configured to displace the stroke rod to: (1) aspirate a liquid specimen into the pipette tip held on the neck; and (2) to eject the specimen from the pipette tip by means of a tip plunger positively connected to the stroke rod. At least one locking sleeve is arranged coaxially with the stroke rod and configured to be displaceably guided toward the stroke rod in the housing The locking sleeve is configured to inhibit release of a tip plunger from the stroke rod.

First claim

The invention claimed is:

1. A pipette for use with a pipette tip with an integrated tip plunger, the pipette comprising:
a pipette housing extending from a lower end to an upper end;
a neck extending from the lower end of the pipette housing and configured to hold a pipette tip;
a stroke rod comprising an upper end and a lower end and configured to displace a tip plunger in the pipette tip, wherein the stroke rod comprises a receiving means positioned at the lower end of the stroke rod and configured to one of: (i) receive an upper end of the tip plunger of the pipette tip that is held on the neck; (ii) or be inserted into the upper end of the tip plunger,
the stroke rod further comprises a first means for positive connection positioned on the lower end of the stroke rod,
the tip plunger includes an upper tip plunger end and a lower tip plunger end, the tip plunger comprises a second means for positive connection positioned on the upper tip plunger end,
a drive apparatus configured to displace the stroke rod to: (1) aspirate a liquid specimen into the pipette tip held on the neck; and (2) to eject the specimen from the pipette tip by means of a tip plunger positively connected to the stroke rod; and
at least one locking sleeve arranged coaxially with the stroke rod and configured to be displaceably guided toward the stroke rod in the pipette housing,
wherein the at least one locking sleeve is configured to be moved into a locked position in which the at least one locking sleeve borders, on an outside, one of: (1) a lower end of the stroke rod when the stroke rod is positively connected to the tip plunger; and (2) an upper end of the tip plunger when the stroke rod is positively connected to the tip plunger,
wherein the first means for positive connection is configured to positively connect the stroke rod to the second means for positive connection of the tip plunger,
wherein, prior to positive connection between the first means for positive connection and the second means for positive connection, one of: (i) the lower end of the stroke rod is configured to be elastically expanded when the tip plunger is inserted into the receiving means of the stroke rod; (ii) or the stroke rod is configured to be inserted into the receiving means of the tip plunger by the upper end of the tip plunger elastically expanding,
wherein, when the first means for positive connection and the second means for positive connection have entered the positive connection, the elastic expansion of one of: (i) the lower end of the stroke rod; and (ii) the upper end of the tip plunger is at least partly reversed,
wherein in the locked position, the locking sleeve is configured to inhibit release of a tip plunger from the stroke rod positively connected to the tip plunger,
wherein the locking sleeve is configured to be displaced upward out of the locked position so that one of: (1) the lower end of the stroke rod is at least partially released and can be elastically expanded; and (2) the upper end of the tip plunger is at least partially released and can be elastically expanded and the tip plunger is configured to be detached from the stroke rod,
wherein the first means for positively connecting the stroke rod to the tip plunger comprises one of: (1) a circumferential annular groove on the lower end of the stroke rod; and (2) an annular circumferential bead on the lower end of the stroke rod, and
wherein the second means for positively connecting the tip plunger comprises a circumferential annular groove on the upper end of the tip plunger when the first means for positively connecting the tip plunger comprises the annular circumferential bead, and wherein the second means for positively connecting the tip plunger comprises an annular circumferential bead on the upper end of the tip plunger when the first means for positively connecting the tip plunger comprises the annular groove.

2. The pipette according to claim 1 , wherein the stroke rod defines at least one slot running in a longitudinal direction, and wherein when the locking sleeve is in the locked position, the locking sleeve borders the stroke rod on an outside in at least one of a region proximate to the at least one slot.

3. The pipette according to claim 2 , wherein when the stroke rod is in the locked position, the stroke rod is configured to border the tip plunger in a region proximate to the at least one slot.

4. The pipette according to claim 1 , wherein the locking sleeve is connected to an operating element that projects from the pipette housing, and wherein the operating element is configured to be displaced relative to the pipette housing in order to displace the locking sleeve downward into the locked position and upward out of the locked position.

5. The pipette according to claim 1 , further comprising an ejection apparatus comprising:
an ejection rod with an upper end and a lower end and configured to be guided inside an axial bore of the stroke rod to be displaceable in a longitudinal direction of the neck, and wherein the ejection rod is arranged with the lower end above the tip plunger when the tip plunger is connected to the stroke rod; and
a rotating sleeve connected to the ejection rod and configured to displace the ejection rod,
wherein the ejection apparatus is configured to press the tip plunger off of the stroke rod and to press the pipette tip off of the neck by displacing the ejection rod downward when the locking sleeve at least partially releases one of: (1) the stroke rod; and (2) the upper end of the tip plunger.

6. The pipette according to claim 1 , wherein the neck is configured to positively connect to the pipette tip so that the pipette tip is pushed onto the neck with at least one of: (1) elastic constriction of the neck; and (2) elastic expansion of the pipette tip before being positively connected to the neck.

7. The pipette according to claim 6 , further comprising at least one locking sleeve arranged coaxially with the neck and configured to be guided in the pipette housing toward the neck, wherein the at least one locking sleeve is configured to be displaced into a locked position in which the pipette tip one of: (1) borders a neck configured to be constricted by means of a pipette tip being pushed on; and (2) borders a pipette tip that is configured to be expanded by being pushed onto the neck.

8. The pipette tip of claim 7 , wherein the locking sleeve inhibits release of the pipette tip that is positively connected to the neck, and wherein the locking sleeve is configured to be displaced upward out of the locked position so that at least one of: (1) the neck is released and is enabled to be deformed radially inward; and (2) the pipette tip is at least partially released and the pipette tip is configured to be detached from the neck.

9. The pipette according to claim 8 , wherein the neck defines at least one slot running in a longitudinal direction and wherein at least one of: (1) when the locking sleeve is in the locked position, the locking sleeve borders the neck on an inside; and (2) when the locking sleeve is in the locked position, the locking sleeve is configured to border a pipette tip comprising at least one slot running in the longitudinal direction at the upper end and that is positively connected to the neck.

10. The pipette according to claim 9 , wherein the locking sleeve is arranged between the stroke rod and the neck, wherein when the locking sleeve is in the locked position, the locking sleeve borders on an outside of one of: (1) the lower end of the stroke rod; and (2) the upper end of the tip plunger, wherein at a same time the locking sleeve also borders an inside of the neck and inhibits release of a tip plunger positively c

Assignees

• Eppendorf Ag

Inventors

• Kunsch Matthias
• Reichmuth Burkhardt
• Link Holger

Classifications

• B01L2300/123

  Flexible; Elastomeric · CPC title

• B01L2200/141

  Preventing contamination, tampering · CPC title

• B01L3/0224 Primary

  having mechanical means to set stroke length, e.g. movable stops (B01L3/0231, B01L3/0234 take precedence) · CPC title

• B01L3/0217 Primary

  of the plunger pump type · CPC title