Patent ID: 7152504

Claim:
A tube-plug extracting apparatus comprising: a clamping mechanism holding a test tube upright in a plug extracting position; a movable frame being located over the plug extracting position and being moved in a vertical direction without rotating; a chucking mechanism being attached to the movable frame for rotation around a vertical axis and chucking a plug attached to the test tube in the plug extracting position; a rotation mechanism being attached to the movable frame and rotating the chucking mechanism with the plug chucked thereby around the vertical axis; a vertical motion mechanism moving the movable frame in a direction to extract the plug while the chucking mechanism chucking the plug is rotating; ball screws being provided in the vertical motion mechanism and having an extra stroke in which a lower-limit stop position of the movable frame, along with the vertical motion mechanism, is shifted from a chucking position for the plug attached to the test tube of a maximum size to a chucking position for the plug attached to the test tube of a minimum size; and a drive motor being provided in the vertical motion mechanism and drives the ball screws, wherein the chucking mechanism includes: a cylinder being rotatably supported on the movable frame and rotated by the rotation mechanism; and a chuck which is provided on a lower end portion of the cylinder for rotation integral with the cylinder and is opened or closed as a piston rod provided in the cylinder advances or retreats; and wherein the rotation mechanism comprises: a drive motor fixed to the movable frame; a driving sprocket wheel mounted on a rotating shaft of the drive motor; a driven sprocket wheel fixed to the cylinder; and an endless chain wound around the driving sprocket wheel and the driven sprocket wheel.