Abstract: An article of footwear is disclosed that includes a fluid-filled chamber with one or more flexion zones. The flexion zones may be areas of the chamber where a tensile element, for example, is absent, or the flexion zones may be areas of the chamber where opposite surfaces of the chamber are bonded together. The footwear may also include a sole structure with a flexion zone, and the flexion zone of the chamber may be aligned with the flexion zone of the sole structure.

Abstract: A fluid system for an article of footwear or other products is disclosed. In one aspect of the invention, the fluid system includes a pump chamber and a pressure chamber. The pump chamber is formed to exhibit a four layer structure to imparts an expandable configuration. The four layers are bonded to each other such that the sidewall has a zigzag-shaped configuration. In another aspect of the invention, the fluid system includes two pump chambers and a pressure chamber in order to increase the resulting pressure in the pressure chamber. In yet another aspect of the invention, at least one of the two pump chambers has an expandable configuration.

Abstract: A fluid system for an article of footwear or other products is disclosed. In one aspect of the invention, the fluid system includes a pump chamber and a pressure chamber. The pump chamber is formed to exhibit a four layer structure to imparts an expandable configuration. The four layers are bonded to each other such that the sidewall has a zigzag-shaped configuration. In another aspect of the invention, the fluid system includes two pump chambers and a pressure chamber in order to increase the resulting pressure in the pressure chamber. In yet another aspect of the invention, at least one of the two pump chambers has an expandable configuration.

Abstract: An article of athletic footwear having an air-filled bladder disposed in a sole structure is disclosed. The air-filled bladder is in fluid communication with ambient air through a filter that permits ambient air to enter the bladder but restricts liquids and particulates from entering the bladder. In operation, the filter and bladder may be portions of a bladder system that absorb shock when the footwear contacts a playing surface. Alternatively, the filter and bladder may be portions of a bladder system that ventilates the interior of the footwear. The filter may be formed of a material such as expanded polytetrafluoroethylene that is attached to a carrier.

Abstract: An article of footwear is disclosed that includes a fluid system having a pump chamber and an inflatable pressure chamber. The pressure chamber is configured to extend at least partially around the pump chamber to limit the pressure of a fluid within the pressure chamber. The relative elevation of the pump chamber and pressure chamber may be selected, for example, such that the pump chamber is within an elevation defined by the upper and lower surfaces of the pressure chamber. The fluid system may be substantially formed from a pair of polymer layers that are bonded together to form the pump chamber and the pressure chamber, and the fluid system includes valves located between the layers.