Patent ID: 7648546

Claim:
A filter comprising pleated filter media having a plurality of pleats defined by wall segments extending axially along an axial direction along an axis and extending transversely along a transverse direction between first and second sets of pleat tips at first and second sets of axially extending bend lines, said transverse direction being normal to said axial direction, said pleated filter media spanning laterally along a lateral span along a lateral direction, with said wall segments being spaced from each other by lateral gaps along said lateral direction, said lateral direction being normal to said transverse direction and normal to said axial direction, said pleats having a pleat depth along said transverse direction along said wall segments between said first and second sets of pleat tips, said pleat depth varying as said pleated filter media spans laterally along said lateral direction, wherein said pleated filter media spans along an annular shape in a plane normal to said axis, said annular shape having at least first and second span sections, at least said first span section being curved, said pleat depth at said first span section being less than said pleat depth at said second span section, wherein said annular shape defines a hollow interior elongated alone a longitudinal direction in said plane normal to said axis, said annular shape comprising two distally oppositely longitudinally spaced curved span sections joined by a pair of longitudinal sections extending longitudinally therebetween, said pleat depth at said two curved span sections being less than said pleat depth at at least one of said pair of longitudinal sections, wherein said pleat depth at said two curved span sections is less than said pleat depth at both of said pair of longitudinal sections.