Patent ID: 7513372
Filing Date: 2009-04-07
Classification: A01K,B01D

Abstract:
1. A filter assembly, comprising: a continuous flexible resilient generally cylindrical helical coil including a plurality of interconnected generally circular helical coils, each coil having a regular sinusoidal-shape in the direction of the helix formed from flat wire stock, including opposed flat top and bottom surfaces with said top and bottom surfaces of adjacent coils in contact at circumferentially spaced locations and forming loop-shaped filter pores between adjacent coils; and a drive mechanism activated by a controller movable to a plurality of fixed positions for engaging and accurately moving one end of said helical coil relative the other end of said helical coil to accurately increase or decrease a volume of said loop-shaped filter pores between said adjacent coils, wherein said drive mechanism functions independently of any difference in pressure between an interior and an exterior of said helical coil while filtering a fluid.