摘要 |
In a folding device for flexible sheet material, a plurality of longitudinally in-line sheet contactor members (1a-23a), called contactors, are provided, each of which are controllably pivotally movable about a pivot axis (113) so as to collectively pivot a sheet (102) about its score line (110). The contactors are controlled so that they have a successive undulating wave action and are formed in sets including a sheet infeed set (121) and a sheet discharge set (123), with an intermediate set (122) disposed therebetween. All of the contactors in the various sets are arranged to have a fixed "at rest" position from which they move. Under the influence of a control device (1b-23b), the contactors individually and pivotally move through varying angles from their respective at rest positions to contact and fold the sheet. The incremental angular displacement of each contactor is such that the leading edge of a sheet progressing from one contactor station to the next downstream station will not be distorted. Any group of contactors in contact with the sheet at any given time throughout the cycle are disposed in a straight line to provide support for the folding portion along its entire length. The sheet infeed set of contactors is such that each contactor (1a-6a) has the same at rest position-normally horizontal or 0 DEG . |