GB625163A - Improvements relating to liquid filters - Google Patents

Abstract

625,163. Filters. ALLAM, P. S. (Fram Corporation). Feb. 13, 1947, No. 4186. [Class 46]. A filter element comprises a continuous sheet of paper or other filtering material having substantial rigidity, of generally tubular form, and axially collapsed to provide contaminant - collecting walls diverging from transversely - extending fold-lines. As shown in Fig. 6, a sheet of paper or the like 11 is scored along lines 12 to 15 and then made up into tubular form, Fig. 7. When pressure is brought to bear on the ends of the element and on the longer horizontal lines 15, the element assumes the concertina-like configuration of Fig. 8, in which the score lines 14 have all become outward folds 21 in planes transverse to the axis, and the score lines 15 have become outward folds 24. Further pressure on the ends of the element results in the configuration, as shown in Fig. 2. A perforated tube 31, Fig. 1, is then inserted in the element, and circular end plates 33 affixed. The element is then threaded over a central tube 41, in a casing 36, and rests on a washer 45 and flange 46. A further washer 44 is threaded on the tube 41 and a spring. 43 interposed between the cap 38 and casing 36. The element 20 may be encased in an outer perforated metal cylindrical tube, the edges of which are connected to those of the end plates 33 before being inserted in the casing. The latter outer perforated tube may have a hexagonal cross-section corresponding in shape with the element, and the end plates may be shaped accordingly. The element may be formed from a cylinder of unscored sheet material, the concertina-like configuration being brought about by pressure at the ends and at appropriate places along the sides.