JP2008082817A - Pipette tip detaching mechanism and dispenser - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the damage of a sealing member when a pipette tip is detached. <P>SOLUTION: An inclined part 45 inclined so as to widen an opening upward is formed to a groove end surface part 44. The angle θ of inclination of the inclined part 45 satisfies the condition of α<β and L0<L1 when the taper angle of inclination of a tip part 26 is set to α; the angle of inclination of the tangential line of the lower corner part of a nozzle rib part with the sealing member is set to β; the distance in a height direction between the position A crossing the side wall of the tip part 26 and the upper end part of the inclined part 45 is set to L0 and the distance in a height direction between the lower and upper end parts of the inclined part 45 is set to L1. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pipette tip removal mechanism for removing a pipette tip, and a dispensing device provided with this pipette tip removal mechanism.

  Conventionally, various dispensing devices for dispensing a liquid sample or the like onto a reaction measuring chip have been proposed. When dispensing a liquid using a pipette tip in this dispensing device, it is necessary to attach and remove the pipette tip to and from the dispensing nozzle.

In order to remove the pipette tip, the automatic dispensing device described in Patent Document 1 is provided with a projecting piece having a notch, and the pipette tip is engaged with the notch and removed. Thus, when removing the pipette tip using the notch, after the pipette tip is removed, the sealing member attached to the distal end portion of the dispensing tube and the removing member constituting the notch are in contact, It is also conceivable that the sealing member is damaged.
JP-A-5-232124

  The present invention has been made in consideration of the above-mentioned facts, and a pipette tip removing mechanism capable of suppressing damage to a sealing member when removing a pipette tip, and a dispensing device equipped with the pipette tip removing mechanism. The purpose is to provide.

  In order to solve the above problems, a pipette tip removing mechanism according to claim 1 of the present invention is formed on a tip portion inserted into a pipette tip and having a tapered shape with a small diameter toward the tip, and above the tip. A dispensing nozzle having a nozzle rib portion protruding outward in the radial direction and having a diameter smaller than the maximum outer diameter of the pipette tip; and disposed at the tip of the dispensing nozzle, and an inner wall of the pipette tip A sealing member that seals the gap, and a groove end surface portion that forms a removal groove that is wider than the nozzle rib portion and narrower than the maximum outer diameter of the pipette tip, and the pipette tip is smaller than the removal groove. A tip removing member that is disposed on the lower side and engages with the removal groove, and the dispensing nozzle is disposed on the upper side of the groove end surface. When it is relatively moved upward with respect to wood, the possible saving unit which is evacuated to the outside from the removable groove such that the sealing member and the non-contact is formed, characterized by.

  2. The pipette tip removal mechanism according to claim 1, wherein when the pipette tip attached to the dispensing nozzle is removed, the tip removal member is removed so that the pipette tip is disposed below the removal groove. A dispensing nozzle is engaged with the groove. Then, the dispensing nozzle is moved relative to the tip removal member in the upward direction. Then, the pipette tip is pushed by the lower surface of the tip removing member, and the pipette tip is removed from the dispensing nozzle.

  Here, when the dispensing nozzle is engaged in a state shifted to either direction with respect to the width direction of the removal groove, the dispensing nozzle is pressed against the groove end surface portion on one side. In this case, after the pipette tip is removed, if the dispensing nozzle is further moved upward relative to the tip removal member, the sealing member may collide with the groove end surface portion and the sealing member may be damaged. .

  Therefore, in the pipette tip removal mechanism according to the first aspect, the retracting portion is formed on the groove end surface portion. Since the retracting portion is retracted outward from the removal groove so that the groove end surface portion is not in contact with the sealing member, collision between the sealing member and the groove end surface portion can be prevented, and damage to the sealing member is suppressed. be able to.

  The pipette tip detaching mechanism according to claim 2 of the present invention is characterized in that the retracting portion is inclined so that the detaching groove becomes wider toward the upper side.

  Thus, the retracting portion can be configured by the inclined surface.

  The pipette tip removal mechanism according to claim 3 of the present invention is characterized in that the inclination angle of the inclined surface is θ, the taper inclination angle of the tip portion is α, the inclination angle of the tangent line between the lower corner portion of the nozzle rib portion and the sealing member is β , When the tangent to the sealing member at the inclination angle θ is drawn, the distance in the height direction between the position intersecting the side wall of the tip and the upper end of the retracting portion is L0, and the lower end and the upper end of the retracting portion If the distance in the height direction from the part is L1, the condition of α <θ <β and L0 <L1 is satisfied.

  By setting it as the structure which satisfy | fills said conditions, the collision with a dispensing nozzle and a sealing member can be prevented.

  A dispensing apparatus according to a fourth aspect of the present invention includes the pipette tip removing mechanism according to any one of the first to third aspects.

  According to the dispensing apparatus of the present invention, collision between the dispensing nozzle and the sealing member can be prevented, so that liquid can be supplied appropriately.

  Since this invention set it as the said structure, the damage of the sealing member at the time of removing a pipette tip can be suppressed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The dispensing device according to the present invention can be used when supplying a sample in a measuring device such as a biosensor.

  As shown in FIG. 1, the dispensing device 10 according to the present embodiment includes a dispensing head 20 and a tip removing member 40. The dispensing head 20 is movable in the vertical direction (Z direction) by a vertical drive mechanism 16 including a motor 16A and a drive shaft 16B arranged in the Z direction.

  The dispensing head 20 includes a head 22 and a dispensing nozzle 24. The head 22 has a prismatic shape elongated in the Y direction. Twelve tubular dispensing nozzles 24 are attached to the head 22 in a line in the Y direction. The twelve dispensing nozzles 24 are moved in the Z direction together with the head 22. A pipette tip 30 is attached to the tip of each dispensing nozzle 24.

  The dispensing head 20 is used to supply a liquid sample to the measuring chip 50 shown in FIG. The measurement chip 50 is formed in a long shape along the head 22 and includes six liquid channels 52 each having an entrance / exit 53 formed on the upper surface. The twelve dispensing nozzles 24 are paired with two adjacent nozzles, one for liquid supply and the other for liquid discharge.

  In the liquid replacement by the dispensing head 20, the pipette tip 30 attached to the dispensing nozzle 24 is inserted into the inlet / outlet 53 of the liquid channel 52, and the sample is discharged from the six dispensing nozzles 24 for supplying liquid, The sample in the liquid channel 52 is sucked by the six dispensing nozzles 24 for discharging the liquid. Thereby, the liquid replacement in the liquid flow path 52 is performed.

  As shown in FIG. 3, the distal end portion 26 of the dispensing nozzle 24 has a tapered shape with a smaller diameter toward the distal end. An O-ring 27 is attached to the proximal end side of the distal end portion 26. The tip 26 is inserted into the pipette tip 30. When the O-ring 27 is press-fitted into the inner wall of the pipette tip 30, the gap with the pipette tip 30 is sealed, and the pipette tip 30 is attached. A packing ring other than the O-ring can also be used. The pipette tip 30 is attached to the dispensing nozzle 24 so that the upper end thereof is in contact with the nozzle rib portion 28.

  A nozzle rib portion 28 is formed on the upper side of the distal end portion 26. The nozzle rib portion 28 protrudes in an annular shape outward in the radial direction of the dispensing nozzle 24. The outer diameter of the nozzle rib portion 28 is smaller than the maximum outer diameter of the pipette tip 30.

  As shown in FIG. 1, the tip removing member 40 is formed in a plate shape along the Y direction, and a removal groove 42 that can engage the dispensing nozzle 24 is formed at a position corresponding to the 12 dispensing nozzles 24. It is configured. As shown in FIGS. 4 and 5, the removal groove 42 includes a groove end surface portion 44. As shown in FIG. 4, the removal groove 42 is elongated in the X direction, which is the relative movement direction of the dispensing nozzle 24 and the tip removing member 40, as viewed from above, and the X direction dispensing nozzle 24 side is open. The back side is arcuate. The width of the removal groove 42 in the Y direction orthogonal to the X direction is configured to be wider than the outer diameter of the nozzle rib portion 28 and narrower than the outer diameter of the pipette tip 30. The opening 41 in the X direction of the removal groove 42 is tapered so as to expand outward. As described above, the wide opening 41 allows the dispensing nozzle 24 to be guided to the central portion of the removal groove 42 even if the position of the dispensing nozzle 24 is slightly shifted.

  As shown in FIG. 5, the groove end surface portion 44 is formed with an inclined portion 45 that is inclined so that the opening becomes wider toward the upper side. As shown in FIG. 5, the inclination angle θ of the inclined portion 45 is set such that the taper inclination angle of the tip portion 26 is α, the inclination angle of the tangent line between the lower corner portion of the nozzle rib portion and the sealing member is β, and the sealing at the inclination angle θ. When the tangent to the member is drawn, the distance in the height direction between the position A that intersects the side wall of the tip portion 26 and the upper end portion of the inclined portion 45 is L0, and the height direction between the lower end portion and the upper end portion of the inclined portion 45 is When the distance is L1, the conditions of α <θ <β and L0 <L1 are satisfied.

  By setting the inclination angle θ and the distance L1 in this way, the collision between the O-ring 27 and the tip removing member 40 can be prevented when removing the pipette tip 30 as described later.

  Next, the removal operation of the pipette tip 30 in this embodiment will be described.

  When removing the pipette tip 30, first, as shown in FIG. 4, the dispensing head 20 is moved to the top of the tip removing member 40, the dispensing nozzle 24 is engaged with the removal groove 42, and the removal is performed. The groove 42 is moved from the opening 41 side to the back side. Next, the chip removing member 40 is pulled upward. Then, as shown in FIG. 6 (A), the upper surface of the pipette tip 30 is pushed by the lower surface of the tip removing member 40, and the pipette tip 30 is removed as shown in FIG. 6 (B). The removed pipette tip 30 falls and is collected in a collection box (not shown).

  Thereafter, when the dispensing nozzle 24 is further lifted, the tip portion 26 of the dispensing nozzle 24 passes through the removal groove 42 without the pipette tip 30 being attached. At this time, when the dispensing nozzle 24 is engaged with the removal groove 42 in a state shifted in the Y direction with respect to the center line M (see FIG. 4) of the removal groove 42, the inside of the removal groove 42. Deviation occurs at. First, as shown in FIG. 7A, the nozzle rib portion 28 is pressed against one groove end surface portion 44, and the dispensing nozzle 24 is raised in this state. When the nozzle rib portion 28 passes through the inclined portion 45, the nozzle rib portion 28 rises while being in contact with the inclined portion 45 as shown in FIG. Next, as shown in FIG. 7C, in the state where the nozzle rib portion 28 is in contact with the inclined portion 45, the tip portion 26 is formed at the corner portion formed between the groove end surface portion 44 and the inclined portion 45. Ascends and rises. At this time, since the inclined portion 45 is set to an angle θ that does not contact the O-ring 27, the inclined portion 45 and the O-ring 27 are not slidably contacted.

  Next, as shown in FIG. 7-2 (D), when the nozzle rib portion 28 is pulled up above the inclined portion 45, the tip end portion 26 becomes a corner portion formed between the groove end surface portion 44 and the inclined portion 45. Ascends and rises. Also in this case, since the inclined portion 45 is set to an angle θ that does not contact the O-ring 27, the inclined portion 45 and the O-ring 27 are not slidably contacted.

  Then, as shown in FIG. 7-2 (E), when the tip of the tip portion 26 reaches the inclined portion 45, the tip of the tip portion 26 is raised while abutting against the inclined portion 45, and the dispensing nozzle 24 removes the tip. It is arranged above the member 40.

  At this height position, the dispensing head 20 is moved to the top of a tip stocker (not shown) loaded with a new pipette tip, and the new pipette tip 30 is attached to the dispensing nozzle 24.

  According to this embodiment, since the inclined portion 45 is formed in the tip removing member 40, the tip removing member 40 and the O-ring 27 do not collide when the pipette tip 30 is removed, and the O-ring 27 Can prevent damage.

  In the present embodiment, the inclined portion 45 is configured to prevent contact between the O-ring 27 and the chip removing member 40. However, the inclined portion 45 does not necessarily have to be an inclined surface, and can have any shape. For example, as shown in FIG. 8, the upper portion of the groove end surface portion 44 is notched so as to have an L-shaped cross section, whereby the retracting portion 46 can be configured to prevent contact between the O-ring 27 and the chip removing member 40. In this case, the retracting width W1 of the retracting portion 46 is shorter than the protruding width W0 of the nozzle rib portion 28 (W0> W1), and retracts more than the height distance H0 from the lower side of the nozzle rib portion 28 to the lower side of the O-ring 27. The height H1 of the portion 46 is configured to be long (H0 <H1).

  Moreover, although this embodiment demonstrated the dispensing apparatus 10 which has the some dispensing nozzle 24, it can also be used for the dispensing apparatus which has one dispensing nozzle.

It is a schematic perspective view of the dispensing apparatus of this embodiment. It is a side view which shows the access state to the measurement chip | tip of the dispensing nozzle of the dispensing apparatus of this embodiment. It is a side view which shows the state by which the pipette tip is attached to the dispensing nozzle of this embodiment. It is a top view which shows the state by which a dispensing nozzle is engaged with one removal groove | channel of this embodiment. It is a figure which shows the relationship between the front-end | tip part of a dispensing nozzle and the chip | tip removal member seen from the side surface of this embodiment. It is operation | movement explanatory drawing at the time of removing a pipette tip from a dispensing nozzle with the tip removal member of this embodiment. It is explanatory drawing which shows the relationship between a dispensing nozzle and a chip | tip removal member when a dispensing nozzle is pulled up in this embodiment. It is explanatory drawing which shows the relationship between a dispensing nozzle and a chip | tip removal member when a dispensing nozzle is pulled up in this embodiment. It is a figure which shows the modification of the chip | tip removal member of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Dispensing apparatus 20 Dispensing head 24 Dispensing nozzle 26 Tip part 27 O ring 28 Nozzle rib part 30 Pipette tip 40 Tip removal member 41 Opening part 42 Removal groove 44 Groove end surface part 45 Inclination part 46 Retraction part 50 Measurement chip 52 Liquid flow Road

Claims (4)

A tip portion that is inserted into the pipette tip and has a tapered shape with a small diameter toward the tip, and is formed on the upper side of the tip portion, protrudes radially outward, and has a diameter smaller than the maximum outer diameter of the pipette tip. A dispensing nozzle having a nozzle rib portion;
A sealing member that is disposed at the tip of the dispensing nozzle and seals a gap with the inner wall of the pipette tip;
It has a groove end surface part that constitutes a removal groove that is wider than the nozzle rib part and narrower than the maximum outer diameter of the pipette tip, and the pipette tip is arranged below the removal groove. A tip removal member with which the dispensing nozzle is engaged with the removal groove;
With
On the upper side of the groove end surface portion, the dispensing nozzle is retracted outward from the removal groove so as not to contact the sealing member when the dispensing nozzle is moved upward relative to the tip removal member. A pipette tip removal mechanism characterized in that a retracting portion is formed.   2. The pipette tip removal mechanism according to claim 1, wherein the retracting portion has an inclined surface such that the removal groove becomes wider toward the upper side.   The inclination angle of the inclined surface is θ, the taper inclination angle of the tip portion is α, the inclination angle of the tangent line between the lower corner portion of the nozzle rib portion and the sealing member is β, and the tangent line to the sealing member at the inclination angle θ L1 is the distance in the height direction between the position intersecting the side wall of the tip and the upper end of the retracting portion, and L0 is the distance in the height direction between the lower end and the upper end of the retracting portion. The pipette tip removal mechanism according to claim 2, wherein the conditions of α <θ <β and L0 <L1 are satisfied.   A dispensing device comprising the pipette tip removal mechanism according to any one of claims 1 to 3.

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