| 摘要 |
1,135,658. Folding edges of non-metallic sheet material. THOMAS BROADBENT & SONS Ltd. 1 Aug., 1967 [17 Aug., 1966], No. 36751/66. Heading B5K. [Also in Division D1] A foldable sheet 12, Fig. 2, e.g. a laundry workpiece, is folded by supporting the sheet in an open condition, restraining it along a fold line against upward movement, directing a curtain of air upwardly from below along a line to one side of the fold line to raise a portion of the sheet at said one side of the fold line from its supported position, and causing the raised portion to swing across the fold line and then downwardly by constraining at least some of the air of the curtain to flow across the fold line. In one embodiment, Fig. 2, a sheet 12 is stationarily supported on a platform 13 having longitudinal parallel slots 14 therein and rods 15 extending along the inner margins of the slots 14. A blast pipe 16 is disposed beneath each slot 14. A transversely arched guide sheet 17 is situated above each rod 15 and pipe 16. Air blasts from the pipes 16 first fold the margins 20 of the sheet 1 to positions 22 and then to fully folded positions 21. In another embodiment, Figs. 4 and 8, the sheet 25 is supported by a conveyer 4 comprising a plurality of narrow tapes and a pair of parallel rods 1 supported from a projection 3 and each lying inwardly of a gap between two conveyer tapes. Arched guide sheets 32 are arranged above blast pipes 16. When the forward end of the sheet 25 reaches a feeler 26 a timing mechanism is actuated to cause (a) the conveyer 4 to stop, (b) a platform 27 to be raised by rams 28 to receive the tape 4 and the pipes 16 in channels 30, 31 therein and to clamp the sheet 25 against the rods 1, Fig. 5(not shown), (c) air to be issued upwardly from the pipes 16 so that the sheet margins are folded over, Fig. 6 (not shown), and (d) the platform 27 is lowered and the conveyer 4 is restarted so that the folded sheet passes between a pressure roll 10 and a platform 35 to crease the sheet. In a modification, Fig. 9 (not shown), the rods (1) are provided with slightly divergent extensions (40) to enhance the neatness of the fold prior to the sheet passing beneath the roll (10). If the folded margins (41), (42) of the sheet overlap the issue of air from the blast pipes is separately timed. In a further modification, Fig. 10 (not shown), the sheet is folded whilst moving on a travelling conveyer (4) the tapes of which are roughly surfaced and the rods 1 being smoothly surfaced. In another modification, Fig. 11 (not shown), for folding a stationary sheet, the platform 27 of Fig. 4 is replaced by bars (45) located in gaps between the conveyer tapes and vertically movable by pneumatic jacks (46).
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