Patent ID: 6837951

Claim:
A method for forming a resilient, fluid-filled bladder structure, the method comprising steps of: placing at least one core between a first sheet and a second sheet of thermoplastic material, said at least one core having a first outer layer and a second outer layer, said outer layers being spaced apart and connected together by a plurality of connecting members; heating said first sheet, said second sheet, and said at least one core; and bonding said first sheet to said first outer layer, bonding said second sheet to said second outer layer, and bonding said first sheet and said second sheet together around a periphery of said at least one core by compressing said first sheet, said second sheet, and said at least one core in a mold such that: a) a first portion of said mold contacts said first sheet adjacent to said first outer layer to bond said first sheet to said first outer layer, and said first portion of said mold contacts and shapes substantially all of a sidewall area of said first sheet to form a sidewall of said bladder from said sidewall area, b) a second portion of said mold contacts said second sheet adjacent to said second outer layer, thereby bonding said second sheet to said second outer layer, and c) said first sheet and said second sheet are compressed together around the periphery of said at least one core to form a peripheral bond between said second sheet and said sidewall of said first sheet.