Automated capper for automated blood sample processing systems

A capper assembly comprising:

• a cap receptacle portion;
• a cap bowl portion;
• a cap comprising a cap cavity having a cylindrical inner surface along an inner diameter in a top of the cap, and a cap surface between the inner diameter and an outer diameter on the top of the cap;
• a track portion;
• a cap retaining mechanism that includes two discrete, flat gripper fingers that are mounted on separate axes and held closed by a spring;
• a thru-beam sensor configured to detect the cap retained within the cap retaining mechanism;
• a vertically-oriented capper portion;
• a capper rod comprising a capper tip having a cylindrical outer surface aligned with the cap retaining mechanism, wherein in an engage mode the capper rod is configured to engage the cylindrical outer surface of the capper tip snugly against the cylindrical inner surface of the cap cavity of the cap retained within the cap retaining mechanism and push the cap with the cylindrical inner surface of the cap cavity engaged to the capper tip into an open end of a sample tube, and wherein the spring is configured with a tension that holds the cap in place between the gripper fingers until the cap cavity and capper tip are engaged, and that allows the gripper fingers to be pivoted open by passage of the engaged cap;
• a moveable capper sleeve enclosing the capper rod;
• an air cylinder comprising a pneumatic piston rod;
• and
• a bracket securing the pneumatic piston rod and the moveable capper sleeve in a fixed position relative to one another,
• wherein the air cylinder and the capper rod are affixed to and are stationary with respect to the vertically-oriented capper portion, and
• wherein the pneumatic piston rod is configured to push the moveable capper sleeve downward against the cap surface to disengage the cap cavity of the cap from the capper tip of the capper rod and maintain a seal of the cap on the open end of the sample tube when a disengage mode is actuated.

A method for automated capping of a sample tube, the method comprising:

• receiving a new cap from a cap track into a cap retaining mechanism, wherein the cap comprises a cap cavity that has a cylindrical inner surface along an inner diameter in a top of the cap, and an upper surface around an outside of the inner diameter on the top of the cap;
• detecting that the cap is retained within a cap retaining mechanism by a thru-beam sensor, wherein the cap retaining mechanism includes two discrete, gripper fingers that are mounted on separate axes and held closed by a spring;
• engaging the cylindrical inner surface of the cap cavity of the new cap that is in the cap retaining mechanism snugly against a cylindrical outer surface of a capper tip of a vertically-oriented capper rod, wherein the vertically-oriented capper rod is enveloped by a capper sleeve that is movable with respect to the capper rod, and wherein the spring is configured with a tension that holds the new cap in place between the gripper fingers until the cap cavity and capper tip are engaged;
• while the cylindrical inner surface of the cap cavity is engaged to the capper tip, pushing the new cap downward from the cap retaining mechanism into an open end of the sample tube with the capper rod to cause an outer surface of the new cap to engage with an opening of the sample tube, and wherein the spring is configured with the tension that allows the gripper fingers to be driven open by passage of the engaged new cap downward;
• and
• while the outer surface of the new cap is engaged with the inside surface of the sample tube, push the capper sleeve downward against the upper surface of the new cap to disengage the cylindrical inner surface of the cap cavity from the cylindrical outer surface of the capper tip and maintain a seal of the new cap on the opening of the sample tube during the disengagement.