Patent ID: 6752886
Filing Date: 2004-06-22
Classification: B23K,B29C,B29L

Abstract:
A method for connecting two workpieces (33, 34; 53, 54) to each other by ultrasonic welding, comprising the steps of: using a vibratory structure (1) having a sonotrode (3, 57), a convertor (2) and an ultrasonic generator (7) for supplying ultrasonic energy to said converter (2); providing said two workpieces (33, 34; 53, 54) which are to be connected and a piece (35, 60) of a meltable material for welding said workpieces to each other; moving said sonotrode (3, 57) into a direction of one of said workpieces (34, 54); starting a welding process by switching on said ultrasonic generator (7) for setting at least said sonotrode (3, 57) into mechanical vibrations for melting said piece (35, 60); determining a state parameter being representative for a contact between a face (32) of said sonotrode (3) and said one of said workpieces (34) or between both said workpieces (53, 54) as a result of said movement of said sonotrode (3, 57); and terminating said welding process by switching off said ultrasonic generator (7) when said state parameter deviates by a predetermined amount from a preselected value as a result of said contact.