Apparatus and method for mixing specimens in vials

1. An apparatus for engaging and moving a mixer disposed in an uncovered, upstanding specimen container, the top of the mixer having a cavity defined by an upstanding annular wall, the apparatus comprising:

a holder adapted to releasably engage the annular wall of the mixer, the holder mounted above the container for vertical movement relative thereto and comprising a collet having flexible fingers that fit within the cavity of the mixer and are expandable to engage the inner surface of the annular wall;

a clamping actuator for selectively causing the holder to engage or release the annular wall of the mixer by selectively moving the fingers radially to expand or contract the collet into or out of engagement with the inner surface of the annular wall of the mixer, wherein the clamping actuator comprises an axially movable central plunger within the collet interior, at least one of the plunger and the interior having a tapered surface, whereby axial movement of the plunger causes radial movement of the fingers; and

a vertical actuator for moving the holder along a vertical axis.

2. An apparatus according to claim 1 , wherein the collet is rotatable about the vertical axis to mix the specimen.

3. An apparatus according to claim 2 , further comprising a controller coordinating operation of the actuators, the controller first causing the collet to descend and then engage the annular wall, then causing the collet to elevate the mixer sufficiently to prevent contact of the mixer with the container during mixing, and then causing the collet to rotate the mixer to mix the specimen.

4. An apparatus for engaging and moving a mixer disposed in an uncovered, upstanding specimen container, the top of the mixer having a cavity defined by an upstanding annular wall, the apparatus comprising:

a holder adapted to releasably engage the annular wall of the mixer, the holder mounted above the container for vertical movement relative thereto;

a vertical actuator for moving the holder along a vertical axis;

a clamping actuator for selectively causing the holder to engage or release the annular wall of the mixer;

a mixing actuator for effecting movement of the holder to cause the mixer to mix the specimen; and

a controller coordinating operation of the actuators, the controller first causing the holder to descend and then engage the annular wall, then causing the holder to elevate the mixer sufficiently to prevent contact of the mixer with the container during mixing, and then causing the holder to move the mixer to mix the specimen.

5. A method of mixing a specimen in an uncovered, upstanding container having disposed therein a mixer with a cavity defined by an upstanding annular wall, comprising the steps of:

engaging the annular wall of the mixer with a movable holder;

elevating the holder and the mixer sufficiently to prevent contact of the mixer with the container during mixing;

moving the mixer to mix the specimen; and

disengaging the holder from the mixer.

6. A method according to claim 5 , wherein the step of moving the mixer comprises moving the mixer at a selected speed for a selected duration.

7. A method according to claim 5 , wherein the step of engaging the annular wall of the mixer comprises inserting the holder in the cavity and expanding the holder into engagement with the annular wall.

8. A method according to claim 7 , wherein the step of mixing the specimen comprises rotating the holder and the mixer about a vertical axis.

9. A method according to claim 8 , wherein the step of moving the mixer comprises moving the mixer at a selected speed for a selected duration.

10. A method according to claim 5 , wherein the step of mixing the specimen comprises rotating the holder and the mixer about a vertical axis.

11. A method according to claim 10 , wherein the step of moving the mixer comprises moving the mixer at a selected speed for a selected duration.