| 摘要 |
880,812. Filters. GENERAL MOTORS Ltd. Dec. 23, 1958 [Jan. 15, 1958], No. 1503/58. Class 46. [Also in Group XXVIII] A filter element 4, Fig. 2, formed by folding a strip of resin impregnated paper along transverse lines 2 to form accordian pleats 3 and securing the ends together to form an annulus is collapsed for storage purposes so that the pleats fall into two equal groups with their inner folds in a common plane or in parallel planes as shown in Fig. 3, and with the pleats lying normally to said plane or planes ; the pack being held compacted by a retaining band 6. Spacing dimples 5 project from each pleat. In a modification the margins of a strip 10, Fig. 4, of filter paper are coated with adhesive 11 which after folding along transverse lines 12 serve to seal both opposite ends of the pleats. The fold lines 12 are of W-cross-section thereby yielding outer folds 22, Fig. 9, of V-section and inner folds 23 of W-section which assist dimples 14.... 18 in spacing adjacent pleats. Prior to use, the compacted element is allowed to assume its unconstrained annular form and is mounted within a casing. |
