This application claims priority under 35 U.S.C. §119(a) to Application No. 07110399.89, filed in Europe on Jun. 15, 200, the entirety of which is expressly incorporated herein by reference.
1. Field of the Invention
The present invention relates to a folding apparatus that includes a feed unit for supplying a medium to be folded, a folding substrate forming a convexly curved support surface for the medium and adapted to be driven back and forth in a circumferential direction of the support surface, and a pinch and guide structure for folding and guiding the medium on the support surface, wherein the pinch and guide structure includes two endless belts each of which is arranged to have a belt portion held in mating engagement with a portion of the curved support surface, so that the two endless belts define two separate paths for the medium.
2. Description of Background Art
A folding apparatus of this type has been disclosed in EP 0 717 486 A1. A similar apparatus is described in EP 05 90 359 A1.
It is an object of the present invention to provide a folding apparatus of the type indicated above which has a simple construction and an improved operational flexibility.
In order to achieve this object, according to the present invention, the folding substrate and the pinch and guide structure define a closed circulation path, in which the two separate paths are joined at a point remote from the feed unit.
The portion of the belt held in mating engagement with the support surface will smoothly and reliably guide the medium along the support surface. Since the belt portion may easily be deflected in the direction away from the support surface, the pinch and guide structure may easily adapt to media with varying thicknesses and configurations. Thus, the folding apparatus according to the present invention is particularly useful for forming crossfolds in media that have been fan-folded into a multi-layer structure in a preceding folding station.
Moreover, the endless belt may be driven so as to move with a speed that is essentially identical with the speed of the surface of the folding substrate, so that the sheet may be conveyed without any substantial friction and, consequently, reduced risk of shear strain and damage.
Since the two separate paths are joined at a point remote from the feed unit, it is possible to accommodate larger media.
The folding substrate may be a drum or an endless belt, so that the medium that is being processed may be caused to revolve in the apparatus. In this way, by suitably controlling a discharge gate that is disposed at the periphery of the endless folding substrate, it is possible to discharge a folded sheet in either of two orientations, so that, if the medium to be folded is a design drawing, for example, the legend of the drawing may always be placed in the right position.
A pinch roller may be provided for pressing the belt against the support surface of the substrate at the position where the fold is to be formed. This pinch roller may at the same time serve as a deflection roller for deflecting the endless belt or may be provided in addition to a set of deflection rollers and arranged at an intermediate portion of the belt that is in mating engagement with the support surface.
Preferably, the pinch and guide structure comprises a pair of endless belts and associated deflection rollers and/or pinch rollers arranged symmetrically with respect to the feed unit. This provides a high flexibility in forming different folding patterns, including zig-zag folds and C-folds.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:
The present invention will now be described with reference to the accompanying drawings, wherein the same reference numerals have been used to identify the same or similar elements throughout the several views.
As is shown in
The feed unit 10 comprises a guide channel 18 arranged for guiding sheet-like media (not shown in
Two deflection fingers 22 and 24 are arranged at the downstream end of the feed unit 12 for deflecting the sheets at the transit point between the feed unit 10 and the surface of the drum 12. The deflection fingers 22, 24 are adjustable by means of a set mechanism that has not been shown, so that they may optionally be brought into an operative position. In the example shown in
Each pinch and guide structure 14 comprises a pinch roller 26 and an endless belt 28 or rather an array of several parallel belts that are trained around the pinch roller 26 and two deflection rollers 30 and 32. The pinch roller 26 and the deflection rollers 30, 32 are arranged such that a portion 28a of the belt 28 is held in mating engagement with the peripheral surface of the drum 12. In the example shown, the portion 28a extends over an angle of almost 180° from the feed unit 10 to the discharge unit 16. The belt 28 may be elastic, or one of the deflection rollers, e.g., the roller 30, may be supported elastically so as to hold the belt 28 under appropriate tension, so that the portion 28a will suitably be pressed against the surface of the drum 12.
The drum 12 is connected to a drive mechanism (not shown) so as to be rotatable in either direction about its central axis. The belts 28 and the pinch rollers and deflection rollers may be driven through frictional contact with the peripheral surface of the drum 12. Preferably, however, one of the pinch rollers 26 and deflection rollers 30, 32 of each pinch and guide structure 14 is driven actively by means of a drive mechanism (not shown).
The discharge unit 16 comprises a discharge gate 34 that is disposed between the two deflection rollers 32 and is pivotable about an axis 36. Further, a pair of discharge rollers 38 form a transport nip below the deflection rollers 32.
Thus, when the gate 34 is in the position shown in phantom lines, a sheet that is conveyed downwardly between the surface of the drum 12 and the belts 28 on the left side of the drum will be separated from the drum surface by the fingers 40 and guided into the nip of the discharge rollers 38 so as to be discharged from the apparatus. On the other hand, when the gate 34 is in the position shown in solid lines, the leading edge of a sheet that is paid out between the belts 28 and the drum surface will be deflected into the narrowing gap between the drum surface and the belts 28 of the other pinch and guide structure 14 (on the right side in
It will be clear that the gate 34 may also be pivoted into a position mirror-symmetrical to the one shown in phantom lines in
The function principle of the folding apparatus will now be explained in conjunction with
This process is illustrated further in
In
When the drum 12 is rotated further in counter clock-wise direction, as in
If the sheet is to be discharged in reverse orientation, with the fold 50 at the trailing end, the step that has been illustrated in
Another mode of operation, for forming a C-fold in a sheet, will now be explained in conjunction with
Then, as shown in
The blouse 56 is then pinched between the pinch roller 26 and the belt 28 on the one hand and the surface of the drum 12 on the other hand, so that a second fold 58 is formed, as has been illustrated in
In the example shown in
When handling multi-layer sheets such as the sheet 44 in
It will be understood that a plurality of different folding patterns can be formed simply by suitably controlling the timings at which the rotation of the drum 12 is reversed and at which the deflection fingers 22, 24 and the gate 34 are operated.
In the apparatus that has been described above, the belts 28 are deflected at their top ends by the pinch rollers 26 which may be supported in such a manner that they are elastically biased against the surface of the drum 12 so as to exert a suitable pinching pressure onto the sheet so as to form the folds therein. In a modified embodiment, however, the positions of the pinch rollers 26 in
In a modified embodiment (not shown), however, friction may be reduced further by training an endless belt around the two drums 12′, so that this belt will then form the folding substrate. Optionally, this belt may be backed by stationary guides comparable to the guides 60 in
The embodiments discussed in conjunction with
All embodiments have the advantage that the belts 28 keep the sheets or the folded packets close to the surface of the folding substrate and smoothly guide the same, especially when they are moved synchronously with the folding substrate. Since the sheet or packet is suitably pressed against the surface of the folding substrate on almost the entire length of its path, it is successfully prevented from sliding sideways in the apparatus.
The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.
Number | Date | Country | Kind |
---|---|---|---|
07110399.8 | Jun 2007 | EP | regional |