Method and apparatus for folding multi-sheet paper products, especially for the further longitudinal folding of newspapers having a transverse break

A method and apparatus for folding multi-sheet paper products, especially for forming a further longitudinal fold at newspapers having a transverse break. During the formation of the fold or shortly before there is produced a bend in the sheets to be folded, whose curvature is opposite to the curvature of the fold to be formed. In this way there are avoided ray-like extending crease folds in the innermost sheets of the folded product. The apparatus for performing the method contemplates providing a folding element having at least one pair of folding edges which extend in the same direction at their effective region and are laterally spaced from one another, so that there is left free an intermediate space into which there can be displaced the innermost sheets of the product to be folded during the folding operation. The folding edges can be formed at the circumference of rotating, preferably coaxial folding disks, which coact with a smooth or profiled counter disk.

BACKGROUND OF THE INVENTION 
The present invention relates to a new and improved method of folding 
multi-sheet paper products, especially for applying a further longitudinal 
fold to paper products in the form of newspapers having a transverse 
break, and further, the invention pertains to novel apparatus for the 
performance of the aforementioned method. 
During the folding of multi-sheet paper products phenomena arise with 
increasing thickness of such products, which at least are disturbing, when 
the paper product is again opened. These phenomena are attributed to the 
fact that theoretically it is only the innermost situated sheet of the 
fold which is to be formed which in the strictest sense really is 
"folded," whereas the remaining sheets so-to-speak are more or less "bent" 
about the "fold" of each next inner sheet. Therefore, during the folding 
operation the sheets of the paper products, which are comparable to the 
layers or plies of a layered product, must be capable of displacement 
relative to one another. Yet, particularly when forming the folds by 
automatic folding machines, this possibility of achieving such 
displacement is not always ensured, particulary in those cases where there 
is already formed in the paper product a pre-fold extending transversely 
with respect to the fold to be formed. If, however, during the course of 
the folding operation there is not possible such displacement of the 
sheets relative to one another, then the spine of the fold tends to 
so-to-speak "split," i.e., the outermost sheet or sheets of the fold tear 
or, however, there occurs an undesired creasing of the innermost sheets. 
To understand this more fully, reference at this point will be made to 
FIGS. 1, 2a, 3a, where the foregoing shall be explained in detail in 
conjunction with the folding of a newspaper. 
Now in FIG. 1 there is shown a newspaper 10 composed of a number of sheets 
11 which have been thrice commonly folded. The first performed fold, 
referred to in the art as the "first longitudinal fold," has been 
designated in the drawing by reference character 12 and the next 
subsequent fold which is formed, designated in the art as the "transverse 
break," is designated by reference character 13. If the newspaper is again 
folded and, specifically, transverse to the transverse break 13, then 
there is formed a second longitudinal fold, or, as it is referred to the 
so-called "post office fold" or briefly "post fold" 14. This expression 
"post office fold" is predicated on the fact that certain postal 
authorities refuse to handle single copies if they are in a shape of 
format resulting from the transverse break 13. FIGS. 1 and 3a illustrate 
the newspaper in a position where it is halfways open about such post fold 
14. When producing the post fold or post office fold 14 there is not 
possible a relative displacement of the sheets 11 with respect to one 
another owing to the presence of the transverse break 13 and also the 
first longitudinal fold 12. As a result the sheets located innermost at 
the post fold 14 are creased. This can be clearly recognized by referring 
to FIG. 2a where there is shown a photographic section through the 
newspaper 10 with closed post fold 14 at the region of the transverse 
break 13. Now if the newspaper of FIG. 2a is opened then such creases 
appear in the form of ray-like crease folds 15 which emanate from the 
intersection point of the post fold 14 with the transverse break 13. These 
crease folds 15 are disturbing and can retard the readability of the 
printed text appearing at the innermost sheets near the post fold 14. This 
becomes even more disturbing since at the sheet innermost with respect to 
the post fold 14 there also is printed the title sheet or the final sheet 
of the newspaper, and these, as is well known, have particular 
significance in promoting the sale of the newspaper and attracting the 
attention of a potential reader. 
Now in order to avoid these crease folds, German Pat. No. 931,656 has 
already proposed perforating the sheets at the location of the second 
longitudinal fold and then, after producing the transverse break, but 
prior to producing the second longitudinal fold, separating these sheets 
along the perforations. However, when doing so there appears at the centre 
of each sheet a slot, which is just as, if not more, disturbing than the 
aforementioned crease folds. 
SUMMARY OF THE INVENTION 
Therefore, with the foregoing in mind it is a primary object of the present 
invention to provide an improved method of, and apparatus for, folding 
multi-sheet articles in a manner not associated with the aforementioned 
drawbacks and limitations of the prior art proposals. 
Another and more specific object of the present inventionn aims at the 
provision of a new and improved method of, and apparatus for, folding 
paper products, and wherein specifically it is possible to fold paper 
products having even considerably more than one hundred sheets, without 
producing the unorderly crease folds at the innermost sheets. 
In order to further understand the invention there has been shown in FIG. 
2b a sectional view, analogous to the showing of FIG. 2a, however of a 
newspaper 10' folded according to the invention, and in FIG. 3b this 
newspaper is shown half open at the post fold 14'. It will be observed 
that at the region of the post fold 14' part of the sheets which are 
located at the inside of the fold 14' have one and only one bend 15' which 
can be referred to as a "counter fold." This "counter fold" or bend 15' 
takes-up the region of such sheets which are prevented from carrying out a 
relative displacement or shifting. With the newspaper opened this "counter 
fold" appears in the form of a tapered pleated fold, as clearly evident by 
referring to FIG. 3b. This result is obtained by the practice of the 
proposed method of the invention. With the proposed method the sheets 
dispositioned to both sides of the fold which is to be produced are 
conjointly pivoted towards one another, wherein, as contemplated by the 
invention, at the region of the fold to be produced, a bend is formed at a 
multiplicity of the sheets located at the inside of such fold, this bend 
having a curvature which is opposite to the curvature of the fold to be 
produced. 
To perform the method the invention proposes an apparatus having at least 
one folding element which is effective at the inside of the fold to be 
produced. This apparatus is manifested by the features that the folding 
element has a pair of folding edges which are directed in the same sense 
at their effective region and are arranged laterally spaced from one 
another. Thus, during the course of production of the fold the 
multiplicity of the sheets located at such region and at the inside 
thereof can move into the intermediate space between both of the fold 
edges, i.e., there is formed the bend curved opposite to the fold.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Based upon the discussion of FIGS. 1, 2a, 2b, 3a and 3b as previously made 
herein, there will now be described the apparatus for performing the 
folding method of the invention, initially reference being made to FIGS. 4 
to 8 inclusive. With the apparatus 20 shown in FIGS. 4 and 5 there will be 
recognized that a machine frame 22 having two side walls 23 and 24 is 
supported upon the support members or legs 21. Three rollers or rolls 28, 
29 and 30 are seated upon a shaft 27 which extends between and is 
rotatively mounted at the side walls 23 and 24 at locations 25 and 26, 
respectively. Trained about each of these rolls or rollers 28, 29 and 30, 
which have practically the same diameter, is a flat belt 31, 32 and 33, 
respectively. These flat belts 31, 32 and 33 lead to rollers or rolls 34, 
35 and 36 respectively, which are seated for rotation at a rotatably 
mounted shaft 39 which likewise extends between the side walls 23 and 24 
and is rotatably secured thereat at the locations 37 and 38 respectively. 
There is additionally seated upon shaft 39 a sprocket wheel 40 which is 
operatively coupled by means of a chain 41 with a drive motor 42 with 
which there is flanged miter or bevel gearing 43. The elements 28 to 36 
thus form a belt conveyor 44 which serves the purpose of infeeding the 
incoming paper products, here the newspapers Z with a leading transverse 
break 13, to the folding operations. 
At a part 45 of the side wall 23 which protrudes past the side wall 24, 
there is freely rotatably mounted in a bearing support or bearing means 46 
a flexed arm 47. This flexed arm 47 extends away from the bearing support 
46 essentially horizontally and at an inclination towards the roll 35. At 
the end of the arm 47 which is remote from the bearing support 46, there 
is secured a downwardly directed flat iron element or member 48 and at 
this downwardly depending member 48 there is freely rotatably mounted a 
contact element. The contact element can have the shape of a contact roll, 
since its function resides in pressing the incoming newspapers Z against 
the belt or band 32, and thus, ensuring that the newspapers will be 
further displaced until their trailing edge departs from the band or belt 
conveyor 44. In the embodiment under discussion, however, for the sake of 
simplicity the contact element is constructed the same as the subsequently 
arranged and still to be described fold discs or plates. A ball bearing 49 
is embeded in the flat iron member 48, as best seen by referring to FIG. 
6. At the ball bearing 49 there are mounted two hub elements or parts 51 
and 52 which are threaded together in axial direction by means of a bolt 
50 or equivalent structure. Drawn over the circumference of each of the 
hub elements 51 and 52 is a respective ring-shaped or annular disc 53 and 
54, the thickness of which decreases towards the outer circumference, so 
that such only bear at the newspaper with a comparatively narrow 
circumferential edge 55 and 56, respectively. At the part of the arm 47 
which extends through the bearing support 46 there is attached a further 
arm 58 provided with a weight 57. Apart from the inherent weight of the 
arms 47 and 58, the weight 57 thus determines the contact force exerted by 
the discs 53 and 54 upon the newspaper Z. This contact force, as will be 
readily understood, is to be accommodated to the paper products which are 
infed to the apparatus. Therefore, the weight 57 can be removed by any 
suitable and thus, not particularly shown means and can be exchanged for a 
different weight which is then secured to the arm 58. 
Following the band or belt conveyor 44 there is attached a guide plate or 
member 59 and 60, for instance a sheet metal guide plate, at each side 
wall 23 and 24. The edges of these guide members 59 and 60 which are 
situated opposite the side walls 23 and 24, as best seen by referring to 
FIGS. 7, 7a and 8, can be downwardly bevelled and form a respective guide 
edge 61 and 62 which, viewed in the direction of through passage, 
initially converge towards one another (at the centre of the showing of 
FIG. 5) and then extend parallel to one another (according to the 
right-hand portion of FIG. 5) and ascend over their entire length 
(reference being made to FIG. 4). 
There is freely pivotably mounted a further flexed or bent arm 64 in a 
bearing support 63 in the elevated part 45. This arm 64 is constructed and 
shaped in the same manner as the arm or arm member 47. At the end of the 
arm 64 which is remote from the bearing support 63 there are likewise 
mounted to be freely rotatable two coaxial discs or plates 65 and 66 in 
spaced relationship from one another. The construction and shape of the 
discs 65 and 66 corresponds to that of the discs 53 and 54 discussed 
previously in conjunction with FIG. 6. As best seen by referring to FIGS. 
7 and 7a, the circumferential edges 67 and 68 of these two discs 65 and 66 
roll upon the forwardly advanced newspaper Z, while exerting a pressing or 
contact force, this newspaper being supported at the opposite side upon a 
counter roll or roller 69. This contact force emanates from an arm 75 
provided with a weight 74 and connected with the arm 64. The counter roll 
69 is seated upon a shaft 70 arranged parallel to the shaft 39 and at the 
same elevation. This shaft 70 is rotatably mounted in the side walls 23 
and 24 at locations 71 and 72, respectively, and additionally, carries a 
sprocket wheel 73 meshing with the chain 41, as best seen by referring to 
FIG. 4. 
The newspaper Z is not only positively forwardly advanced at the location 
of the discs or plates 65 and 66, due to the drive of the roller 69 into 
the gap between such discs and by the action of the circumferential edges 
66 and 67, but also, as best seen by referring to FIGS. 7 and 7a, is 
somewhat raised to both sides of the discs 65 and 66 due to the ascending 
guide edges 61 and 62. As a result the region of the sheets of the 
newspaper Z, located between the discs 65 and 66 and which sheets are 
situated closest to such region, tend to bow out upwardly and therefore, 
there is now achieved a pre-stage of the counter fold 15' discussed 
previously in conjunction with FIGS. 2b and 3b. This upward bulging or 
bowing out can be augmented, particularly in the case of extremely thick 
paper products and/or those whose sheets have low sliding properties in 
that, as shown in FIG. 7, the counter roll 69 is provided with a collar 76 
extending about its outer surface. This collar 76 is aligned with the 
intermediate space between the discs 65 and 66. 
Furthermore, in a bearing support 77 provided at the part 45 there is yet 
pivotably mounted a further arm or arm member 78 which is constructed 
analogous to the arms or arm members 47 and 64, and connected with an arm 
or arm member 80 carrying a weight 79. At the end of the arm 78 remote 
from the bearing support 77 there are freely rotatably mounted, in spaced 
relationship from one another, two coaxial discs or plates 81 and 82. The 
construction and form of these discs 81 and 82 likewise correspond to the 
discs 53 and 54 previously described in conjunction with FIG. 4. The 
circumferential edges 83 and 84 of the discs 81 and 82 roll, while 
exerting a contact force depending upon the size of the weight 79, upon 
the further forwardly advanced newspaper Z which has been moved from the 
conveying gap between the counter roll 69 and the circumferential edges 67 
and 68. This newspaper Z is supported upon a shaped or profiled roll or 
roller 85 located at the oppositely situated side. The profiled roll 85 is 
provided at its circumference or periphery with a folding groove 86 and is 
seated upon a shaft 87, which, in turn, analogous to the shafts 39 and 70, 
is rotatably mounted at locations 88 and 89 at the side walls 23 and 24, 
respectively. Also seated upon the shaft 87 is a sprocket wheel 90 which 
meshes with the chain 41 which is held in a tensioned state by means of a 
tensioning wheel 91. The circumferential edges 83 and 84 here act in 
conjunction with the folding or fold groove 86 and with the guide edges 61 
and 62 which are located higher and closer to one another at the region of 
the discs 81 and 82, as the actual folding edges which initiate folding of 
the newspaper Z transversely with respect to the leading fold or 
transverse break 13. 
Now since the fold edges 83 and 84 have a spacing from one another, i.e., 
there is left free therebetween an intermediate space 92, the region of 
the sheets of the newspaper Z located between the discs or plates 81 and 
82 and closest to such region, experience an upward bowing-out, as shown 
in FIG. 8. Additionally, the driven profiled roll 85 in conjunction with 
the discs 81 and 82 also functions as a further feed or advancing element 
which further forwardly displaces the newspapers Z, which thus are 
gradually closed due to the ascending and mutually converging guide edges 
61 and 62. Following the profiled roll 85 of the paired discs 81 and 82, 
at the region where the guide edges 61 and 62 practically extend in 
parallelism with respect to one another, are two pairs of practically 
vertical axis-press or contact drums or rolls 93, 94 and 95 and 96. The 
contact drums or rolls 93, 94 possess a comparatively narrow contact rim 
97, as best seen by referring to FIG. 4, whereas the contact or press 
drums 95 and 96 are cylindrical. As also best seen by referring to FIG. 4, 
the contact roll or drum 94 is keyed or otherwise appropriately connected 
to the upper end of a shaft 100 mounted in ball bearings 99 in a bearing 
box 98 between the side walls 24 and 25. In this connection, attention is 
also directed to FIG. 9. At the lower end of the shaft 100 there is pinned 
thereto a sprocket wheel 101 which meshes with a chain 102, this chain, in 
turn, being guided about a drive wheel or gear 103 which is arranged at 
the miter or bevel gearing 43 flanged to the drive motor 42 (see FIG. 9). 
Between both ball bearings 99 there is mounted a rocker or balance 104 
which is pivotable about the shaft 100. At the free end of the rocker or 
balance 104 there is clamped a shaft 105 extending essentially parallel to 
the shaft 100. Ball bearings 106 rotatably mount the contact or press drum 
or roll 95 upon the shaft 105. From the showing of FIG. 5 it will be 
apparent that a compression spring 106, supported at the inside of the 
side wall 23, acts upon the rocker or balance 104, so that the contact 
drum or roll 95 is resiliently pre-biased towards the contact or press 
roll or drum 96. The contact drum 96, on the other hand, similar to the 
contact or press drum 94, is keyed to a shaft 107 which is stationarily 
and rotatably mounted in the bearing box 96, as best seen by referring to 
FIG. 9. Seated upon shaft 107 is a sprocket wheel 108 which, in turn, 
likewise meshes with the chain 102 which is held in a tensioned state by 
the tension wheel 109. Pivotably mounted upon the shaft 107 is likewise a 
rocker or balance 110 at whose end there is clamped a shaft 111 upon which 
there is rotatably mounted the contact or press drum 93. The rocker or 
balance 110 is exposed to the action of a pressure or compression spring 
112 (FIG. 5) supported at the side wall 24, whereby the contact or press 
drum 93 is resiliently urged towards the contact or press drum 94. 
In order to ensure that all of the contact drums or rolls 93 to 96 
positively rotate with the same peripheral speed, there is flanged to the 
upper end face or side of each of the contact drums a respective sprocket 
wheel 113, 114, 115 and 116. The sprocket wheel 114 arranged at the 
directly driven contact drum 94 is connected by means of a chain 117 with 
the sprocket wheel 115 at the resiliently biased contact drum 95. The 
sprocket wheel 116 arranged at the directly driven contact drum or roll 96 
is connected by means of a chain 118 with the sprocket wheel 113 at the 
resiliently biased contact or press drum 93. Apart from the further 
conveying of the upright newspapers Z which stand at the produced fold, 
the contact drums 93 and 94 exert, by means of their contact or press rims 
97, a compressing or pressing action at the newspaper at the region of, 
however not quite at the produced fold, whereas the contact drums 95 and 
96, owing to their cyclindrical outer surface, definitely press the 
produced fold 14' together with the counter folds 15' formed at the inside 
thereof, so that the newspaper, after departing from the apparatus 20, 
constitutes a stable, practically quadrilateral or square structure which 
does not have any great tendency to open. 
It has been found that with the described apparatus 20 newspapers having 
considerably more than one hundred pages, i.e., with considerably more 
than fifty sheets, can be readily faultlessly folded a third time and 
without the risk of forming an over-stressed or even torn fold spine. The 
result of this corresponds to a common folding of well over one hundred 
superimposed paper layers or plies. 
Finally, in FIGS. 10 and 10a there is shown a simpler constructional 
embodiment of the apparatus in schematic view, serving for folding less 
thick paper products. This apparatus 120, in principle, operates like a 
sword folding apparatus. Following a conveyor band or belt 121 there is 
arranged a pair of contact rolls or drums 122 and 123. At least one of the 
contact rolls or drums 122 and 123 is driven, in FIG. 10 it is the contact 
drum 122, so that such can rotate in the direction of the arrows 124 and 
125. Equally one of the contact drums 122 or 123 is resiliently biased 
towards the other contact drum. Between both of the contact drums or rolls 
122 and 123 there is present a fold or folding gap 126. A folding sword 
127 having two folding edges 129 and 130 extending parallel to the axes of 
the contact drums or rolls 122 and 123 and spaced from one another by an 
intermediate space or a channel or throat 128 is aligned towards the 
folding gap 126 and driven up and down, by any suitable and therefore not 
particularly illustrated drive in the direction of the double-headed arrow 
131. The conveyor belt or band 121 transports the paper products Z' which 
are to be folded in the direction of the arrow 132 over the contact drums 
or rolls 122 and 123 until the paper products strike against a stop or 
impact member 133. Now the folding sword 127 performs a work stroke in the 
direction of the folding gap 126. Since both folding edges 129 and 130 
leave a space therebetween, the sheets of the paper product which 
neighbour the folding edges 129 and 130 are caused to bend into such 
space, so that as shown in FIG. 10, there also is formed within the fold 
14' the counter fold 15'. 
FIG. 10a shows a variant of the folding sword 127. This modified 
construction of the folding sword 127 will be seen to have a sectional 
shape in the form of approximately a fork or bifurcated member. 
While there are shown and described present preferred embodiments of the 
invention, it is to be distinctly understood that the invention is not 
limited thereto, but may be otherwise variously embodied and practiced 
within the scope of the following claims. Accordingly,