Fluid filter element

#1. Field of the Invention

#The invention concerns a fluid filter element and method for forming same.

#2. Description of Prior Art

#Preferred embodiments of the present invention are described in greater detail hereinafter with reference to the Figures of the drawings in which:

#FIG. 1 is an isometric view of a prior art filter medium;

#FIG. 2 is an isometric view of a part of a prior art fluid filter element which is produced by folding an embossed filter medium of the kind shown in FIG. 1;

#The invention relates to a filter element and method for forming same wherein embossed surfaces are provided on the filter material such that the embossed surfaces extend partially from each side of the filter material whereby, when folded, the embossed surfaces can be positioned substantially parallel and evenly spaced, thereby allowing substantially uniform application of adhesive and providing a resulting filter element having enhanced structural strength.

#FIG. 7 illustrates a portion of a filter in accordance with the present invention. Filter 70 according to the invention is formed from a filter fleece or non-woven cloth material 70′, typically made from glass fiber and plastic fiber components or the like. Embossings 71 are provided in material 70′ which respectively include a first embossing portion 71a which projects out of the surface of the filter fleece material 70′ in one direction and a second embossing portion 71b which adjoins the first embossing portion 71a and which is recessed into the plane of the filter fleece so as to extend from filter fleece material 70′ in the opposite direction. The fold configuration shown here has fold edge regions 73a and 73b respectively which are flattened both in the upstream flow region and also in the downstream flow region. Fold edge regions 73a and 73b define walls 75 of material 70′ therebetween, and embossing portions 71a and 71b advantageously extend between opposite fold edge regions of each wall 75. Embossing portions 71a and 71b are advantageously defined in a single plane, and the plane of embossing portions 71a and 71b is preferably oriented relative to the plane of walls 75 such that when material 70′ is folded into the “V” pattern shown in FIG. 7, embossing portions 71a and 71b are substantially parallel to and equally spaced from embossing portions 71a and 71b of adjacent walls 75.

#Pleat edges are embossed so they are flat and perpendicular to the air flow so as to define fold edge regions 73a and 73b, and can be produced by impressing second fold edges which are disposed in closely juxtaposed relationship, into the filter medium in a lying or flat condition.