Pipette with releasable locking of rotational position of actuating element

Patent metadata

Field	Value
Publication number	US-9295986-B2
Application number	US-201313873755-A
Country	US
Kind code	B2
Filing date	Apr 30, 2013
Priority date	May 2, 2012
Publication date	Mar 29, 2016
Grant date	Mar 29, 2016

Abstract

A pipette for use with pipette tips in which a set metering volume is secured in that the locking body is arranged on the circumference of the annular cylindrical locking element when it is in the locking position. Through this, the transmission part which the locking element comprises on the outer circumference is held fast. The annular cylindrical locking element can be formed separately from a toothed ring for driving a counter mechanism. Thus, it is possible to perform the locking in arbitrary positions or in more selectable rotational positions than in the conventional locking equipment, where a locking element engages into the toothed ring for driving the counter mechanism.

First claim

The invention claimed is:

1. A pipette comprising:
a rod-shaped casing ( 1 . 1 ),
a seat ( 50 ) for detachably holding a pipette tip ( 51 ) on the lower end of the casing ( 1 . 1 ),
a displacement equipment, comprising a displacement chamber ( 57 ) with a limit ( 58 ) that is relocatable therein,
a connection channel ( 56 ), connecting the displacement chamber ( 57 ) with an opening in the seat ( 50 ),
a drive equipment ( 6 ), coupled to the relocatable limit ( 58 ), for relocating the relocatable limit ( 58 ) of the displacement chamber,
adjustable means ( 8 , 25 , 27 ) for limiting the relocation of the relocatable limit ( 58 ) by the drive equipment ( 6 ),
an actuating element ( 4 ), connected to the drive equipment ( 6 ) and projecting out from the upper end of the casing ( 1 . 1 ), for controlling a relocation of the relocatable limit ( 58 ) by relocation along an axis, and for adjusting the adjustable means ( 8 , 25 , 27 ) for limiting by rotating the actuating element ( 4 ),
a cylindrical transmission part ( 19 ), which is rotatable in the casing ( 1 . 1 ) and bearing mounted at a certain position in the axial direction, wherein the actuating element ( 4 ) is relocatable in an axially extending accommodation of the transmission part ( 19 ) and is connected to the transmission part ( 19 ), so as to rotate together with it, via means ( 15 , 16 , 17 , 18 ) for rotation-blocked connection,
first means ( 11 , 14 ) for transmitting a rotational movement of the actuating element ( 4 ) to a movement for adjusting the adjustable means for limiting ( 8 , 25 , 27 ) the relocation, coupled to the actuating element ( 4 ) and the adjustable means for limiting ( 8 , 25 , 27 ) the relocation,
adjustable means ( 23 ) for indicating a metering volume with a display ( 22 ) that is visible from the outside,
second means ( 20 , 21 ) for transmitting a rotational movement of the transmission part ( 19 ) to a movement for adjusting the adjustable means for indicating ( 23 ), coupled to the transmission part ( 19 ) and the adjustable means for indicating ( 23 ),
an annular cylindrical locking element ( 82 ) on the outer circumference of the transmission part ( 19 ),
a locking body ( 85 ) with a partly cylindrical acting surface ( 86 ), which bears against the circumference of the locking element ( 82 ) in the locking position,
means ( 89 ) for relocating the locking body ( 85 ) into the locking position,
at least one unlocking element ( 106 , 107 ), projecting from the casing ( 1 . 1 ) and being movably mounted with respect to the casing ( 1 . 1 ), and
third means ( 92 , 93 ) for transmitting a movement of the unlocking element ( 106 , 107 ) with respect to the casing ( 1 . 1 ) to a movement, away from the locking element ( 82 ), of the locking body ( 85 ) from out the locking position, the third means ( 92 , 93 ) for transmitting being coupled to the locking body ( 85 ) and the unlocking element ( 106 , 107 ).

2. The pipette according to claim 1 , which comprises unlocking elements ( 106 , 107 ), projecting from the casing ( 1 . 1 ) on side walls ( 101 , 102 ) of the casing ( 1 . 1 ) facing away from each other, each of them being coupled to the locking body ( 85 ) via third means ( 92 , 93 ) for transmitting, in order to relocate the locking body ( 85 ) away from the locking element ( 82 ) by actuating the one or the other unlocking element ( 106 , 107 ) at option.

3. The pipette according to claim 1 , wherein the locking element ( 82 ) is a toothed ring ( 83 ) on the circumference of the transmission part ( 19 ) with radially outward directed teeth, and the locking body ( 85 ) has a toothed ring ( 87 ) with radially inward directed teeth on the partly cylindrical acting surface ( 86 ), which engage into the teeth of the locking element ( 82 ) in the locking position.

4. The pipette according to claim 3 , wherein the locking body ( 85 ) has at least 5 and/or at most 35 teeth.

5. The pipette according to claim 4 , wherein the locking body has at least 15 and/or at most 25 teeth.

6. The pipette according to claim 1 , wherein the locking element ( 82 ) is ferromagnetic and the locking body ( 85 ) is magnetic.

7. The pipette according to claim 1 , wherein the locking element ( 82 ) is a brake cylinder and the locking body ( 85 ) is a brake shoe.

8. The pipette according to claim 1 , wherein the third means ( 92 , 93 ) for transmitting comprise a two-arm lever with a first lever arm ( 94 , 95 ), acting on the locking body ( 85 ), and a second lever arm ( 99 , 100 ), which either acts on the unlocking element ( 106 , 107 ) or is itself the unlocking element ( 106 , 107 ).

9. The pipette according to claim 8 , wherein means ( 129 , 130 , 131 , 132 ) for arresting the further lever ( 106 , 107 ) in an unlocking position exist between the further lever ( 106 , 107 ) and the casing ( 1 . 1 ).

10. The pipette according to claim 1 , wherein the lever arms ( 94 , 95 , 99 , 100 ) of the two-arm lever ( 92 , 93 ) are inclined towards each other in an obtuse angle, and/or extend in an arc around the actuating element ( 4 ).

11. The pipette according to claim 1 , wherein the unlocking element ( 106 , 107 ) has a further lever, pivotally mounted in the casing ( 1 . 1 ), with a lever arm ( 125 , 126 ) acting on the third means ( 92 , 93 ) for transmitting and an actuating portion ( 110 , 111 ) protruding from the casing.

12. The pipette according to claim 1 , wherein the means for relocating the locking body ( 85 ) into the locking position comprise a spring element ( 89 ) which loads the locking body ( 85 ) in the locking position and is supported in a spring support ( 88 ) that is fixedly connected to the casing ( 1 . 1 ).

13. The pipette according to claim 1 , wherein the second means ( 20 , 21 ) for transmitting comprise a toothed ring with axially directed teeth on the outer circumference of the transmission part ( 19 ), into which engages a toothed wheel of the means ( 23 ) for indicating.

14. The pipette according to claim 1 , wherein
the drive equipment ( 6 ) comprises an axially relocatable lifting rod for relocating the relocatable limit ( 58 ) of the displacement equipment,
the adjustable means ( 8 , 25 , 27 ) for limiting comprise an upper stop body ( 8 ), relocatable in the axial direction of the lifting rod ( 6 ), a lower stop body ( 27 ) and a stop element ( 25 ), disposed on the circumference of the lifting rod ( 6 ) between the upper and the lower stop body, for limiting the stroke of the lifting rod, and
the actuating element ( 4 ) is connected to the lifting rod ( 6 ).

15. The pipette according to claim 14 , wherein the upper stop body ( 8 ) is a threaded spindle which has an upper passage channel ( 7 ) through which the lifting rod ( 6 ) is guided through and which is screwed into a spindle nut ( 9 ) that is fixedly connected to the casing ( 1 . 1 ), wherein the lower stop body ( 27 ) has a lower passage channel ( 28 ) through which the lifting rod ( 6 ) extends, and wherein the lifting rod ( 6 ) with the stop element ( 25 ) can be relocated between the upper stop body ( 8 ) and the lower stop body ( 27 ).

16. The pipette according to claim 15 , wherein the first means ( 11 , 14 ) for transmitting are further means for connecting the actuating element ( 4 ) to the threaded spindle ( 8 ) so as to rotate together with it, which permit axial relocation of the actuating element ( 4 ) with respect to the threaded spindle ( 8 ).

17. The pipette according to claim 15 , wherein the further means for connecting the actuating element ( 4 ) to the

Assignees

• Eppendorf Ag

Inventors

• Wilmer Jens
• Winter Ingo

Classifications

• B01L3/0224 Primary

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

• B01L2200/14

  Process control and prevention of errors · CPC title

• B01L2300/026

  Drum counters · CPC title

• B01L3/021 Primary

  Pipettes, i.e. with only one conduit for withdrawing and redistributing liquids · CPC title