Patent ID: 8281559

Claim:
A packaging machine having an ultrasonic device, the ultrasonic device comprising: an ultrasonic generator which generates electric vibrations; an ultrasonic converter which converts the generated electric vibrations into mechanical vibrations of the same frequency; a sonotrode having a sound-radiating end surface; a transformation intermediate piece which transfers the mechanical vibrations to the sonotrode; an anvil disposed opposite the sound-radiating end surface of the sonotrode, wherein a sealing plane of a package to be sealed is definable between the anvil and the sound-radiating end surface; an evacuation chamber formed by an upper chamber part and a mobile lower chamber part; and a first seal; wherein the sound-radiating end surface of the sonotrode is for reflecting the mechanical vibrations to form a standing wave to be passed into a packaging foil, the sound-radiating end surface and the anvil are disposable in the evacuation chamber such that the sound-radiating end surface is disposable in a vacuum and/or in a modified atmosphere, the transformation intermediate piece penetrates the upper chamber part, the first seal is provided between the transformation intermediate piece and the upper chamber part, and the first seal is located in a vibration node of the standing wave when the standing wave is formed by the sonotrode.