Apparatus and method for rotary bonding

An apparatus for ultrasonically bonding at least two continuously moving substrate webs together comprising:

• a) an ultrasonic bonding means for providing ultrasonic energy wherein said ultrasonic bonding means includes a rotary ultrasonic horn which is configured to rotate about a bonding axis and which has an outer peripheral bonding surface upon which said substrate webs travel;
• b) a rigid frame;
• c) an anvil support frame which is pivotally connected to said rigid frame at two pivot points located on a pivot axis;
• and
• d) a rotatable anvil roll which has an outer peripheral anvil surface and is rotatably connected to said anvil support frame and which is configured to rotate about an anvil axis and press said substrate webs against said bonding surface of said rotary ultrasonic horn thereby bonding said substrate webs together,
• wherein said anvil support frame is configured to pivot about said pivot axis to maintain said anvil surface in a substantially parallel relationship with said bonding surface of said rotary ultrasonic horn and wherein said pivot axis of said anvil support frame is located a first distance from said bonding axis and said anvil axis is located a second distance from said bonding axis, wherein said second distance is greater than said first distance.