Patent ID: 7383865

Claim:
A welding device for welding a layered portion where a first web and a second web are layered together, the welding device comprising: a drum rotating about an axis; a transfer section provided on a periphery of the drum to rotate together with the drum for transferring the first and second webs while holding the first and second webs thereon; an anvil provided on the periphery of the drum and extending generally in a direction of the axis for rotating together with the drum; a horn provided close to the periphery of the drum, which, together with the anvil, applies a vibration energy to the layered portion; a cutter provided close to the periphery of the drum, which comes into contact with the anvil to cut the first and second webs; a sensor for measuring a distance between the anvil and the horn; and a control section for controlling a relative positions of the anvil and the horn based on the measured distance between the anvil and the horn as measured by the sensor, wherein while the horn, together with the anvil, applies the vibration energy to the first and second webs, the cutting of the first and second webs by the cutter is not performed.