초록 ▼

If a plurality of essentially circular sheets of filter paper are stacked in a pile, the individual sheets have a tendency to stick to each other rendering it difficult to remove the topmost sheet from the pile. To overcome this inconvenience, it is provided that adjacent sheets within the pile have

If a plurality of essentially circular sheets of filter paper are stacked in a pile, the individual sheets have a tendency to stick to each other rendering it difficult to remove the topmost sheet from the pile. To overcome this inconvenience, it is provided that adjacent sheets within the pile have a different contour, e.g. by providing every second sheet with a protruding tongue arranged at the circumferential edge thereof. All the intermediate sheets either do not have such tongue or are provided with a recess arranged anywhere along their circumferential edge.

대표청구항 ▼

A pile comprising a plurality of coaxially arranged, stacked, cup-like filter sheets of substantially equal size; each filter sheet having a generally flat circular bottom wall and a generally frustoconical undulated side wall; said plurality of sheets including first sheets, the top edge of the fru

A pile comprising a plurality of coaxially arranged, stacked, cup-like filter sheets of substantially equal size; each filter sheet having a generally flat circular bottom wall and a generally frustoconical undulated side wall; said plurality of sheets including first sheets, the top edge of the frustoconical side wall of said first sheets having a first shape consisting essentially of a recess in the plane of said sheet to facilitate removal, and second sheets, the top edge of the frustoconical side wall of said second sheets having a second shape; said first sheets and said second sheets being alternately arranged within said pile; the second shape of the top edge of the frustoconical side wall being an uninterrupted undulated shape formed by punching, creasing and shaping in the cup portion to provide an edge portion of the cup portion underlying the recess; and each of the recesses in alternating sheets being located in staggered relation in a different position in respect to the top sheet of the pile whereby removal of the sheet with the recess and the underlying sheet at the adjacent recess location is facilitated.