Patent ID: 7959054

Claim:
A device for processing a workpiece using ultrasound, the workpiece being disposed between the device and an anvil, the device comprising: an ultrasound sonotrode having an end facing the workpiece and the anvil, said sonotrode having inner walls defining an axial recess with an opening disposed in said end of said sonotrode; and a die disposed in said recess to slide directly on said inner walls, said die being pneumatically driven into an operating position in which said die penetrates through said opening to partially project out of said ultrasound sonotrode, wherein, in a rest position, said die is completely retracted within said ultrasound sonotrode and said sonotrode end seats on the workpiece, wherein said sonotrode and said die are disposed, structured and dimensioned such that said die does not follow ultrasound oscillations in said sonotrode.