Rectangular holder for zigzag- folded filter element has frame with long sides engaging omega-shaped projections on long sides of filter and folds of filter are at right angles to long sides

摘要

The filter (1) has a rectangular thin filter element (2) with accordion-folds parallel to the short sides. The folds increase the available filter surface area and give a high resistance to bending in the transverse direction. The long sides (3,4) of the filter element are given a high resistance to bending by reinforcing side strips (5a,5b) with omega-shaped outward projections (6a,6b). The filter element fits into a rectangular frame (7). The omega-shaped outward projections on the filter side strips seal against the inside surfaces (8a,8b) of the long sides of the frame.