Transportation device for successively moving a number of sample containers past a treatment position

Transportation device for successively moving a number of sample containers past a fixed sample treatment position for dispensing or removing liquid into or from said containers, characterized therein that it comprises a carriage mounted in a holder for horizontal displacement in a straight line, a horizontal plate provided with a series of sample containers arranged in a spiral line with respect to a central location, driving means for rotating said plate with respect to said carriage about a vertical shaft concentric with said central location, said driving means being mounted for displacement with said carriage, guiding means comprising two relatively movable interengaging elements, one of said elements being a guide plate connected to said carriage and said horizontal plate by said vertical shaft, said guide plate having a spiral line parallel with the spiral line defined by said sample containers, the other of said two elements being a guide head in engagement with said guide plate spiral line and being fixed with respect to the holder, means connecting said guide plate to said drive means to rotate said guide plate about said vertical shaft and thus rotate said horizontal plate displacing said horizontal plate during said rotation to place successive sample containers at said sample treatment position, said guide plate being also provided with positional markings corresponding to the positions of said containers along said horizontal plate spiral line for actuating a control means for the driving means.