Patent GB-1036323-A (GB)
Title: Method of manufacturing a pleated air filter cartridge
Inventor: DUNCAN SYDNEY F
IPC: B01D46/52
Filed: 1963-08-20
Abstract: 1,036,323. Air filters. FARR CO. Aug. 20, 1963, No. 32864/63. Heading B1T. A method for constructing a pleated air filter of apertured cardboard support strips, a sheet of a filter medium and a cardboard frame, such as is described in the Specification, 1,036,322 comprises applying glue to at least portions of one surface of the strips, positioning a plurality of the strips side by side and securing the filter sheet to the glued surface of the strips; longitudinally folding each of the strips toward the filter sheet and gluing tapes along the ends of the strips for maintaining them in folded relationship; and mounting the taped, glued assembly of strips and filter sheet in the frame. The term 'cardboard' includes chipboard, paperboard, cardboard and certain plastic materials which can be scored and folded. Each support strip 10 is preferably die cut from thin cardboard or chipboard and stacked in a hopper 19, being ejected one at a time by a feeding apparatus 20. The strips 10 then pass between gluing rolls 24 where glue is applied to the front surface of each strip in lateral stripes in positions described in the above-mentioned Specification. A sheet-type filtering material is continuously drawn off a roll 31 and applied to the glued surface of the strips 10 by feed rolls 28, the necessary pressure being applied by pinch rolls 32. The coated strips 10 are then fed into a folding apparatus 33 comprising a pair of roller chains 34, 35 with a blunt pointed pyramidal-shaped bar 36 mounted on each link. The chains 34, 35 advance from left to right as do the strips 10, each strip 10 being folded by the bars 36 along the longitudinal central rib 14. A ram 38 raised and lowered by a cam 41 supports and properly positions the strips 10 immediately in front of the folding apparatus 33. A roll of tape 43 is rotatably mounted on each side of the apparatus 33 adjacent the ends of the strips 10 to which the tape is glued to maintain the strips 10 in folded relationship when the bars 36 are withdrawn from between them at the right hand end of the apparatus 33. A table 44 supports the folded strips 10 and the desired lengths of filter are chopped off by a shearing apparatus 45. The chopped-off lengths of folded, taped filter are assembled in a frame constructed from a flat sheet 46 of cardboard which is cut-scored part-way through along the dashed lines 47 in order to facilitate folding the sides 48 up at right angles to the sheet. Ears 49 on each end of two of the sides 48 are folded inwardly and secured to the remaining two sides such as by staples. A pair of tear-out panels 51 are provided by cut-scoring the sheet 46 and providing finger-holes 52. The two strips of tape 43 on either end of the strip 10 are glued to one pair of sides 48 while flap portions 50 on the other pair of sides 48 are folded over and secured by gluing and staples to the adjacent strips 10. In the assembled filter, the filtering materials 30 faces away from the base of the frame, the air flowing first through the material 30, then through the apertures in the strips 10, and finally through the apertures in the frame formed by tearing out the panels 51.