초록 ▼

An open flow fluid filter has a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips. The loop has a hollow interior extending along an axis. F

An open flow fluid filter has a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips. The loop has a hollow interior extending along an axis. Fluid to be filtered flows through the main filter element from an upstream dirty side to a downstream clean side, and flows axially in the hollow interior. The main filter element has an axial flow passage extending along the axis and circumscribing the hollow interior and has a flow perimeter greater than the inner perimeter. A safety filter element downstream of the main filter element filters both the axial flow in the hollow interior and additional flow between the flow perimeter and the inner perimeter. A filter with additional flow is also provided.

대표청구항 ▼

1. A filter comprising a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, said loop having a hollow interior extending along a given axis,

1. A filter comprising a pleated main filter element having a plurality of pleats in a closed loop having an outer perimeter defined by a plurality of outer pleat tips, and an inner perimeter defined by a plurality of inner pleat tips, said loop having a hollow interior extending along a given axis, wherein fluid to be filtered flows through said main filter element from an upstream dirty side to a downstream clean side, and flows axially in said hollow interior, said main filter element having an axial flow passage extending along said axis and circumscribing said hollow interior and having a flow perimeter greater than said inner perimeter, a safety filter element downstream of said main filter element and filtering both the axial flow in said hollow interior and additional flow between said flow perimeter and said inner perimeter, wherein said main filter element has first and second axial ends, said first axial end being open and providing said axial flow passage therethrough, said safety filter element includes a portion at said first axial end of said main filter element and outside of said hollow interior and axially aligned with the area between said flow perimeter and said inner perimeter, and wherein said inner perimeter defines and bounds a first cross-sectional area, said flow perimeter defines and bounds a second cross-sectional area, said second cross-sectional area, is greater than said first cross-sectional area, the difference between said second and first cross-sectional areas defines a third cross-sectional area common with a portion of said second cross-sectional area and circumscribing said first cross-sectional area, said third cross-sectional area being bounded by said flow perimeter and said inner perimeter and defining an additional flow passage for said additional flow, and wherein said portion of said safety filter element at said first axial end of said main filter element is axially aligned with said third cross-sectional area.