Apparatus for Longitudinal Deformation, for Example by Creasing or Perforation, of Paper Webs Prior to Folding

The present invention relates to apparatus to deform paper webs being printed on in printing machines by creasing or perforating the paper web as it is being passed over a folding triangle or fold former by use of a roller and a counter roller.

Paper webs being worked on in printing machines are deformed in order to facilitate longitudinal folding of the paper webs issuing from the machine; such deformation is particularly desirable in heavier weight paper, deformation facilitating longitudinal folding by means of a triangular fold former if subsequent to longitudinal folding, transverse folding is to be carried out. If the deformation is to be by perforation, then the perforations should be so made that slight openings are formed in the paper having torn or shredded fringes extending outwardly of the paper when folded. The outward direction of the shreds or fringes permit escape of air upon subsequent folding, particularly upon subsequent transverse folding. They also permit accurate longitudinal folding since the shreds or fringes are not pressed at random towards the right or the left as they are passed over the tip of the forming triangle, which might cause lateral deflection of the paper web with respect to the forming triangle. Frequently, a plurality of paper webs are to be adhered at a predetermined adhesion line, and adhesive striping may be applied to the paper web at the outside of the crease to be formed in advance of the fold itself. Providing a crease prevents longitudinal shift of the paper web in the direction of the crease edge - when folded - thus improving adhesion of superimposed paper webs. Damage to the fold edge and formation of tears or fissures are effectively prevented.

It has previously been proposed to provide a separate pre-creasing roller or a perforating roller located in advance of the folding or forming section of a printing machine, driven counter the direction of rotation of the folding triangle inlet guide roller or guide cylinder. Providing such an additional roller requires additional drive apparatus, bearings, and substantially increases the overall height of the apparatus.

It is an object of the present invention to provide a paper-deforming, particularly perforating or creasing device which is so constructed that folding of a paper web is facilitated, which provides outwardly directed perforating fringes on the paper web, which is small and simple to operate and does not require additional power drive systems.

Briefly, a roller pair is located on the forming or folding triangle itself; the perforating or creasing roller is located at that side of the folding triangle (which, as is customary, is made of sheet metal) which is surrounded by the paper as it is being folded over. Usually, this would be at the underside of a folding or forming triangle. The sheet metal element of the triangle is formed with a cut-out through which the deforming roller may extend. A counter roller is located immediately opposite the deforming roller and bears thereagainst. This arrangement prevents lateral shift of superimposed paper webs which are to be adhered together upon subsequent folding, thus improving adhesion of the paper webs. The apparatus can be constructed to be small and can be driven by frictional engagement with the traveling paper webs, thus not requiring any separate drive mechanism.

In accordance with a preferred embodiment, the deforming roller, that is, the perforating wheel or the creasing wheel, is located on a pivot arm which is adjustable with respect to the forming triangle counter the force of a spring, as well as being adjustable laterally thereof with respect to the center line of the folding triangle. Thus, the position of the crease or perforation to be formed with respect to the tip of the folding triangle is easily adjusted.

In accordance with a further feature of the invention, the deforming apparatus can be engaged and disengaged by securing the counter roller on a shaft in such a manner that either the counter roller or its attachment shaft is adjustable transversely of the forming triangle, the shaft being rotatable over a limited angular extent by means of a manually operable lever to lift the counter roller out of engagement with a paper web traveling over the folding triangle.

The invention will be described by way of example with reference to the accompanying drawings, wherein:

FIG. 1 is a highly schematic side view of the apparatus in accordance with the invention, partly in section, taken along line I--I of FIG. 2;

FIG. 2 is a top view of the apparatus of FIG. 1 in the direction of arrow A thereof;

FIGS. 3 and 4 are side views and top views, respectively, of perforating roller pairs;

FIGS. 5 and 6 are side views and top views of creasing roller pairs; and

FIG. 7 is a detail side view illustrating attachment of the counter roller, to an enlarged scale.

A paper web 1 is fed over the folding former feed roller 2, journalled in side walls 3, 4 of the machine to a folding or former triangle 5 having a first or upper side and an obverse or lower side. The paper web is longitudinally folded as it passes over the first side of the former triangle 5. In accordance with the present invention, the deforming roller, which may be a perforating roller 6 or a creasing roller 7, is located the obverse side of the folding triangle 5, i.e. at the side about which the paper web 1 will fold, that is, in the present instance at the bottom side thereof. The deforming roller is replaceable, so that either a creasing roller 7 (FIGS. 5, 6) or a perforating roller 6 (FIGS. 3, 4) can be placed thereon. The folding triangle 5 is formed with a cut-out 8 through which the deforming roller extends. The perforating roller 6, or the replaceable creasing roller 7 is journalled on a pivot lever 9 which is rotatably secured to a shaft 10. Shaft 10 has a hand-operated wheel 12 attached thereto as well as an adjustment ring 11 (FIG. 2). Shaft 10 is journalled in two bearing blocks 13, 14 (FIG. 2). Bearing block 13 has a smooth bore, whereas bearing block 14 is threaded. The shaft 10 is formed at the left-hand side, as shown in FIG. 2, with a thread, and by turning wheel 12, the thread on the shaft 10 can be engaged with the thread in bearing block 14, so that the position of the respective rollers 6, or 7, with respect to the center line, or apex of the folding triangle 5, can be adjusted by moving the entire lever 9 towards the right or left. The position of the lever 9 is fixed by a counter 19 threaded on shaft 10. The up-down movement of the respective deforming wheels 6, 7 in the direction towards or away from the folding triangle 5 or, rather, the cut-out 8 therein, is effected by means of a knurled nut 15 (FIG. 1), threaded on a threaded bolt 16 secured to the folding triangle 5. A spring 17 is interposed between the lever 9 and the folding triangle 5, the nut, when screwed towards the folding triangle, compressing the spring. A limit screw 18 limits the pivoting movement of lever 9.

The perforating roller 6 (FIG. 4) is located between a pair of guide rollers 20, 21. Roller 6 is formed with peripheral teeth (see FIG. 3) which fit in a groove 23 formed in the counter roller 24 (FIG. 4). The creasing roller 7 (FIGS. 5, 6) is a single roller having a creasing edge which engages a counter roller 25 formed with a smooth and somewhat yielding or resilient surface, for example made of Vulkollan, or other yielding, smooth, rubber or plastic materials.

The counter rollers 24, 25, to fit against the perforating roller 6, or the crease roller 7, respectively, are located on a two-part spring-loaded lever 26, 26a (FIGS. 1, 7). The part 26a of the spring-loaded lever is secured on a shaft 27 to be transversely adjustable (FIG. 2), so that the position of the respective counter roller can be adjusted with respect to the deforming roller which is used, and with respect to the transverse adjustment of this deforming roller. Both the deforming roller as well as the counter roller can, thereby, be accurately adjusted with respect to the apex of the folding triangle. A linkage which includes a hand lever 28 (FIGS. 1, 2) and a link 29 which is eccentrically mounted with respect to the hand lever 28 and connected to a holding lever 30 secured to shaft 27 permits rotation of shaft 27 by about 180.degree.. The respective counter roller 24, 25 can thus be lifted from the position shown in solid lines in FIG. 1 to the position shown in chain-dotted lines in FIG. 1, that is, out of engagement with the paper web. As best seen in FIG. 7, lever 26 carrying the counter roller 24, 25 respectively is journalled in lever part 26a by a short shaft or rivet; a spring 35 fits into a depression 34 to resiliently press the end of lever 26 away from the part 26a. A compression spring 36 located within a hollow bolt 37, secured to the part 26a, permits engagement of the respective counter roller 24, 25 against the associated deforming roller 6, 7. Accurate adjustment is effected by means of a knurled knob 38 and a counter or stop nut 39, so that the counter rollers 24, 25 will maintain their respective adjustment with respect to the associated deforming rollers 6, 7. Fine adjustment, or correction of lateral position of the counter rollers 24, 25 is additionally effected by means of a pressure screw 31 which acts against one end of the shaft 27, the other end being longitudinally movable by being held in position by a spring 32 bearing against an end plate closing off the counter bore in side wall 4 of the machine. The adjusted position is locked or secured by means of a counter nut 40.

Various changes and modifications may be made within the scope of the inventive concept.

The releasable attachment of the lever 26a (FIG. 7) on the shaft 27 permits coarse adjustment of the placing of the counter roller, so that former triangles having apex positions differing substantially from those shown in FIG. 2, for example, can be used with paper webs of varying width, or for different folding divisions. The former or folding triangles 5, themselves will carry on the underside the mechanism carrying the deforming rollers 6, 7, the position of the deforming rollers 6, 7 being adjustable with respect to the apex of the particular triangle used, and the position of the counter roller being coarsely adjustable by loosening of the lever elements 26a and sliding it into place, fine adjustment being provided by the arrangement including the nuts 31, 40.