GB520298A - Improvements in or relating to filters - Google Patents

Abstract

520,298. Filters. AUTOMOTIVE PRODUCTS CO., Ltd., and POOLE, L. A. Nov. 3, 1938, No. 31889. [Class 46] In an edge filter formed of a coil of wire or ribbon the coil is supported between relatively movable end members on a former and is normally held in position of minimum spacing by a spring retaining means being provided to hold the end members in a position of greater spacing. As shown in Fig 1, a coil 10 is wound on external longitudinal ribs of a cylindrical former which consists of two parts 11, 12, the part 11 being attached to an end cap 25, seating in a central recess 32 in the head 8 of the housing 26 while the part 12 is fixed in a short sleeve 23, attached to a plate 24 which closes the other end of the housing. A stem 34 fixed to the plate 24 extends through the head 8 and receives a wing nut 36. A spring 44, bearing at one end against a shoulder on the stem 34 and at the other against an internal shoulder on a sleeve 41 formed integrally with a cap 25, draws the two parts of the former together and maintains the minimum spacing of the coil. The parts 11, 12 have longitudinally projecting fingers, 15, 16, normally fitting between one another. When the filter requires cleaning, the nut 36 is removed and the filter drawn out of the housing on the plate 24. The coil is then extended by pulling apart the head 25 and the plate 24 againstthe action of the spring to a position in which, on relative rotation of the parts of the former, V-shaped projections at the ends of the fingers 15 can be engaged in similarly shaped recesses at the ends of the fingers 16, as shown in Fig. 2. The coil is thus held in the external position. Stops are provided on the parts of the former to limit their rotational movement.. The liquid enters the housing through a connection 28 and the filtrate is discharged through a connection 31. In the filter shown in Fig. 4 the former 50 is cast integral with the head 51 of the housing and the lower end of the coil is attached to a ring 66 carried by an end cap 58. The end cap is drawn up by a spring 62 which surrounds a stem 57 fixed to the, cap 58 and bears against a cross-bar 61 on the stem and against a plug 64 screwed into the end of the former. When the end cap is drawn down the crossbar 61 passes through gaps in a flange 63 on the former and, on rotation, engages beneath the flange, so that the coil is held extended for cleansing. The coils may be made as described in Specification 385,755.