Patent ID: 7472527

Claim:
A method for screwing caps onto receptacles with a device comprising a rotary spindle having a first end provided with a cap gripper head and a second end connected to a two-portion clutch member, one of which portions is constrained to rotate with the second end of the rotary spindle, and the other of which portions is constrained to rotate with a drive shaft on the same axis as the spindle and associated with a drive member, the portions of the clutch member comprising a magnetic bell and a magnetic core which have dimensions suitable for enabling it to be engaged in the bell, and are associated with a displacement member for displacing the bell and the core relative to each other between a position in which the core is engaged in the bell and a position in which the core is disengaged from the bell, the method comprising the steps of: gripping a cap when the core is disengaged from the bell, driving the spindle in rotation by engaging the core in the bell, screwing the gripped cap on a neck of one of the receptacles, tightening the gripped cap on the neck with the core engaged in the bell to a depth corresponding to a desired tightening torque.