| 摘要 |
PCT No. PCT/IT96/00066 Sec. 371 Date Dec. 4, 1996 Sec. 102(e) Date Dec. 4, 1996 PCT Filed Apr. 2, 1996 PCT Pub. No. WO96/31399 PCT Pub. Date Oct. 10, 1996A tubular blank of filter paper containing measured and separate quantities of tea, or a similar infusionable substance, is pleated and folded so as to obtain a bag with two envelopes by a method that includes the steps of advancing blanks singly and in succession along a feed direction tangential to an indexing wheel with radial grippers, taking up each blank in a position above three bearing elements ordered along the feed direction, forming a pleat in an intermediate portion of the blank, then pinching the two ends of the blank by use of movable pressure elements interacting with two of the bearing elements so as to prevent the escape of the contents from the envelopes while at the same time drawing the tubular blank toward the wheel to bring the two envelopes together and give the filter bag its final shape. |
