| 摘要 |
583,609. Filters. POST, O. W. June 14, 1945, No. 15155. [Class 46] [Also in Group XVII] A filter comprises an outer hollow element and an inner element adapted to support the filter mass, the elements having mating ground surfaces which provide small passages for the filtrate. In the construction shown in Fig. 1, a filter element B made of glass consists of the stem 14 and a head 15, the periphery of the head being of frusto-conical form to seat within the inner surface 11 of a funnel A. The head 15 is ground, with the aid of abrasive paste, by being rotated against the inner surface 11. In a modification the filter has a head consisting of three parts, as shown in Fig. 4, which have frusto-conical ground peripheries forming annular filter surfaces. In a further modification the filter consists of two telescopically-arranged elements each with a head having a ground filter surface engaging the inner surface of the funnel. |
