Measuring and testing – Sampler – sample handling – etc. – Capture device
Reexamination Certificate
2000-11-22
2001-12-04
Raevis, Robert (Department: 2856)
Measuring and testing
Sampler, sample handling, etc.
Capture device
Reexamination Certificate
active
06324925
ABSTRACT:
FIELD OF THE INVENTION
The object of this invention is a method for removing a replaceable tip for use in a suction device for dispensing, transferring, diluting, titrating, or mixing a liquid, or for a combination of all or some of these operations.
The object of this invention is also a suction device for dispensing, transferring, diluting, titrating or mixing a liquid, or for a combination of all or some of these operations, which suction device has an end part enclosing a cylindrical space having a reciprocating piston for changing the volume of the cylindrical space, the end part being provided with an aperture in the extremity thereof intended for receiving a replaceable tip, in order to form a gas passage between the sample space of the said replaceable tip and the cylindrical space, and which has means for removing the tip.
DESCRIPTION OF THE BACKGROUND ART
Since the 1970s suction devices have been in use, in which the replaceable tip has been released and removed from the body with mechanical means without the need to touch the replaceable tip by hand. This is to avoid getting into contact with active and often even dangerous chemical and biological samples and reagents. The solutions have included mechanisms comprising levers or sleeves which have been mounted upon the pipette body. These mechanisms, which are known among others from the Finnish patent publications 56937 and 57540, have, however, increased the outer dimensions of the body beyond the outer diameter of the replaceable tip. From the U.S. Pat. No. 4,616,514 a suction device is known in which the replaceable tip is attached to the body the end part having finger-like strips provided with shoulders and in which the replaceable tip is released with a moveable means mounted within the end part acting on the finger-like strips. Also in this solution the end part will be greater than the replaceable tip to its diameter. In the development of diagnostic methods, nowadays one strives at such methods, in which the volumes of the samples and reagents utilized are increasingly smaller, which also leads to the use of increasingly smaller sample tubes. The removal means for replaceable tips mounted on the body of the suction device have restrained the changeover to using small sample tubes and therefore the removal devices have been removed from the suction devices. In these cases the tips have to be removed manually, whereby the risk for contamination again increases. There are also procedures in use in which the replaceable tip is removed by means of a U-shaped notch located in the side of a waste container.
In the following, the ‘suction device’ stands for as such known manual or electrical suction devices or pipettes, which are used for pipetting, dispensing, diluting, titrating or mixing, or for a combination of all or some of these operations.
The use of these suction devices in handling liquids, such as samples or reagents, is described as a simplified example in the following. Once a replaceable tip has been attached to the end part of the body of the suction device and the piston moving in the cylindrical space of the end part is brought to its home position, whereby the piston is situated in the cylindrical space at that end which is closest to the end part of the suction device, the handling can be started. The outermost open end of the replaceable tip is immersed into the liquid of which it is desired to take a sample. When the piston is now moved inwards into the cylindrical space, the change in the volume formed jointly by the sample space of the replaceable tip and the cylindrical space brings about suction of the sample or reagent into the sample space of the replaceable tip. When it is desired to dispense the sample or the reagent taken in this way into the tip, the piston is moved towards the end part, whereby the said volume diminishes and at the same time the liquid in the replaceable tip exits from the open end of the replaceable tip. Several of these suction and dispensing stages can be combined in succession to bring about the desired handling. In these stages of sample handling the piston is moved to bring about the desired suction or dispensing. In most cases as the last stage the piston is moved past its home position mentioned above to a blowout position so that the replaceable tip is completely emptied. Thereafter the replaceable tip is removed from the end part of the body of the suction device.
SUMMARY OF THE INVENTION
The object of the invention is to provide a method and a device using the same for removing tips used in suction devices without touching them manually. It is essential for this invention that the means needed for the removal are at least mainly within the body of the suction device and do not thereby increase the outer dimensions of the end part of the suction device beyond the outer diameter of the replaceable tip.
The method being the object of the invention is characterized in that the replaceable tip is removed by bringing a removal means, mounted in the air space formed jointly by the sample space of the replaceable tip and the cylindrical space of the end part of the suction device, which is movable between its two extreme positions, namely an inner home position and an outer removal position, to move into cooperation with an inside surface of the replaceable tip mounted on the end part, whereby the movement of the removal means into its removal position brings about the detachment of the replaceable tip from the end part.
Bringing the removal means into cooperation with the inside surface of the tip means that the movement of the removal means is communicated to cause a removal movement of the replaceable tip attached to the end part of the body of the suction device, e.g. by bringing the removal means in contact with the inside surface of the replaceable tip, or in contact with means associated with the inside surface of the tip, such as projections, pegs, ribs, fins, circular projections, or with means within the said air space engaging the inside surface of the tip.
The removal of the tip in the method according to the invention can take place so that the removal means in moving to the position for removal, extends outside through an aperture in the end part into the sample space of the tip into contact with the inside surface of the tip, or with means associated therewith. According to an alternative embodiment, the means in association with the inside surface of the tip protrude into the cylindrical space of the end part, and are brought there in contact with the removal means.
The method according to the invention is especially suitable for the removal of such replaceable tips which are attached onto the tip of the end part of the body of the suction device most preferably with a friction joint. For the removal according to the invention, such replaceable tips for attachment onto the tip of the end part of the body of the suction device are advantageous, in which the inside diameter of the sample space of the replaceable tip tapers from the point of attachment towards the other end of the replaceable tip. In these cases the removal means can in its position for removal, according to one embodiment, be brought into direct contact with the inside surface of the sample space of the replaceable tip. Further the method according to the invention is preferably suitable for the removal of such replaceable tips for attachment onto the tip of the end part of the body of the suction device, which in that end which is intended to be attached to the body of the suction device, or in its vicinity, on the inside surface of the replaceable tip are provided with projections, pegs, fins, circular projections, transversal ribs or other similar means or means within the sample space of the replaceable tip, over which the removal means comes into contact with the replaceable tip in its position for removal. In this case the removal means comes preferably into contact with only such surfaces which have not been in contact with the sample. When the removal means comes into contac
Ekholm Pertti
Suovaniemi Osmo
Biohit Oyj
Birch & Stewart Kolasch & Birch, LLP
Raevis Robert
LandOfFree
Suction device with means for removing a replaceable tip does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suction device with means for removing a replaceable tip, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suction device with means for removing a replaceable tip will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2566821