Patent ID: 6874301

Claim:
A method of clamping a cap onto a vessel comprising the steps of: providing a cap having threads, a vessel having threads with a predetermined winding angle adapted to engage with the threads of the cap, a capping head holding said cap and a motor for rotating the capping head in a clamping direction; rotating the cap and the vessel relatively with respect to each other at an elevation where the threads on the cap and vessel are not engaged with each other; detecting an incipient position of meshing engagement when the distal ends of the threads of the cap and vessel come into contact with each other by measuring the torque acting on the cap when the distal ends of the threads of the cap and the vessel come into contact with each other; and rotating the cap in a clamping direction by a predetermined rotational angle with respect to the incipient position of meshing engagement to clamp the cap to the vessel.