| 摘要 |
808,268. Gas filters. FRAM CORPORATION. Sept. 30, 1957 [Jan. 10, 1957], No. 30528/57. Class 8(2). Assembly of an air filter element comprising a tube 12, Fig. 2 of filter media e.g. paper having longitudinally extending pleats supported by external and internal screens 10, 11, Figs. 3 and 4, is effected by positioning the inner screen 11 having an unjoined overlap 16 over the upstanding wall 17, Fig. 5, of a jig standing on a flange 18, placing the pleated tube over the screen 11 with the lower zig-zag end resting on a rib 19 of the flange 18, placing the outer screen 10 having an unjoined overlap 15 over the tube 12, placing a clamping band 21,Fig. 10, round the outer screen 10, dipping the end of the assembly remote from the flange 18 into a mould pan 26 to provide an annular end cap 13 of plastic material in which are embedded the ends of the inner and outer screens and of the filter tube, releasing the clamp, removing the jig and finally dipping the other end of the assembly in a mould pan to provide a second end cap 14. The mould pan 26 has an upstanding rib 27 on which the zig-zag end of the pleated tube rests so as to allow access of the plastic material to the space below said end. In a modification the filter tube is of elliptical cross-section. In a further modification one or both the supoorting screens are omitted. Specification 751,655 is referred to. |
