Parallel folded filter
AssigneeDrager Sicherheitstechnik GmbH
InventorOlaf Ziske
Life of this patent
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Abstract
A parallel folded filter has good sealing properties between the folded filter web and the filter housing with the smallest possible amount of sealant. The filter is prepared with an elliptical filter blank, in which the rows (1) of fold lines (locations of predefined fold edges or imaginary fold edges) are at right angles to an axis (4) extending in the direction of the greatest longitudinal extension of the filter blank (2). The circumferential contour of the filter blank (2) is dimensioned such that it assumes a circular shape with the folds stood up (e.g., in a folded state). An adhesive bead (3) is applied along the circumferential contour. A ring-shaped filter housing accommodates the folded filter blank (2) such that a circumferential support surface is present for the adhesive bead (3).
Claims16
A parallel fold filter, comprising:
- an elliptical flat filter blank with rows of fold lines extending at right angles to an axis extending in the direction of a greatest longitudinal extension of said elliptical flat filter blank;
- a circumferential contour of said filter blank that is dimensioned such that said filter blank assumes a circular shape when said filter blank is folded, with folds formed along said fold lines;
- an adhesive bead extending along the circumferential contour;
- and
- a ring-shaped filter housing having an inner contour accommodating said folded filter blank and having a circumferential support surface in contact with said adhesive bead.
The process for preparing a parallel folded filter, comprising the steps of:
- preparing a filter blank, in which rows of fold lines are directed at right angles to an axis extending in the direction of the greatest longitudinal extension of the filter blank in a non-folded flat state;
- dimensioning a circumferential contour of the filter blank such that it assumes a circular shape in a folded state of the filter blank;
- applying an adhesive bead along the circumferential contour;
- positioning the filter blank into a ring-shaped filter housing with the adhesive bead being on the filter blank in a folded state, the ring-shaped filter housing having an inner contour forming a support surface for contacting the adhesive bead.
A parallel fold filter, formed by the process steps comprising:
- providing an elliptical flat filter blank with rows of fold lines extending at right angles to an axis extending in the direction of a greatest longitudinal extension of the elliptical flat filter blank;
- providing a circumferential contour of the filter blank that is dimensioned such that the filter blank assumes a circular shape when the filter blank is folded, with folds formed along the fold lines;
- applying an adhesive bead along the circumferential contour;
- providing a ring-shaped filter housing having an inner contour defining a circumferential support surface;
- disposing the folded filter blank in the housing with the adhesive bead in contact with the circumferential support surface.
A process for preparing a folded filter, the process comprising the steps of:
- providing a flat filter blank;
- applying an adhesive bead in a circumferential contour on the flat filter blank, said circumferential contour having a shape on said flat filter blank to have said circumferential contour create a circular shape in a folded state of the filter blank and to have the circumferential contour have a longitudinal axis extending in a direction of a greatest longitudinal extension of the circumferential contour;
- folding the flat filter blank along rows of fold lines directed at substantially right angles to said longitudinal axis;
- providing a ring shaped filter housing with an inner contour;
- arranging the folded filter blank into the ring-shaped filter housing;
- connecting said inner contour to the adhesive bead.
Dependencies are inferred from the claim text.