Suction head and carrying reaction cups used in biochemical reaction analyzing apparatus

Claim 1

A biochemical reaction analyzing apparatus comprising a reaction cup, a suction head for carrying said reaction cup, means for reducing the pressure in said suction head, and means for increasing the pressure in said suction head; wherein said cup has a hollowed portion providing a reaction cell for biochemical reactions and a top face covered and sealed with a sheet, said suction head being engagable with the sealed top face of the cup, said suction head further comprising: an annular elastic suction pad at its lower end which engages with the top face of the cup to engage with the periphery of the top face of the cup, and a head body provided with an air suction and discharge opening formed inside said suction pad, said head body defining a cylindrical cavity at its lower end and an air passage at its upper end, said cylindrical cavity having a diameter which is substantially equal to a diameter of said opening, said air passage having a diameter which is smaller than the diameters of said cylindrical cavity and said opening, said cylindrical cavity extending up from said opening in a vertical direction and having a length in the vertical direction sufficient to permit a stream of discharged air from said air passage to be guided downward onto the reaction cup through an entire cross-sectional area of said opening; wherein the length of said cylindrical cavity is equal to or greater than half the diameter of the air suction and discharge opening.