Patent ID: 7097440

Claim:
A system for pre-forming an expandable material into an expandable cage for a filter device, comprising: a male mandrel element having a particular shape which forms the shape of the inner surface of the expandable cage, the male mandrel element allowing the expandable material to be deformed, bent or heat set to retain the particular shape of the male mandrel element, the male mandrel element having a channel formed therein; a female die element having a cavity formed therein of a particular shape which forms the outer surface of the expandable cage, the female die element having a length which extends for at least a portion of the length of the male mandrel member, the particular shape of the cavity of the female die element allowing the expandable material to be deformed, bent or heat set to retain the particular shape of the cavity; and a pin receivable within the channel formed in the male mandrel element for maintaining the expandable material aligned relative to the male mandrel element.