GB2144400A - Sheet cutting and folding apparatus - Google Patents

Abstract

Cutting and folding apparatus for a rotary printing machine comprises an upstream cylinder (1) which is provided with folding blades (3, 4) and looped around by the web (13) of material, and a downstream cylinder (2) which has two diametrically opposite cutting strips (9, 10) at its circumference as well as a respective folding flap (11, 12) centrally therebetween. The upstream cylinder (1) has the same diameter as the downstream cylinder (2) and carries two diametrically opposite folding blades (3, 4) at its circumference as well as a respective cutting blade (7, 8), which is disposed centrally between these folding blades and is provided with a row of puncture needles (5, 6).

Description

SPECIFICATION Sheet cutting and folding apparatus The present invention relates to sheet cutting and folding apparatus, especially apparatus for rotary roller printing machines.

Known sheet cutting and folding apparatus com prises puncture-cutting blade first cylinder and a folding flap second cylinder. The first cylinder carries a folding blade and, opposite thereto, a cutting blade provide with a row of puncture needles. The circumference of the first cylinder is equal to the sheet cut-off length. The second cylinder is twice the size of the first cylinder. It has two cutting strips each opposite the other at the circumference as well as a respective folding flap disposed centrally between these strips. A web of material leaving the rotary printing machine is first folded longitudinally by means of a folding funnel. Subsequently, the web is partially looped around the first blade cylinder before it runs into the gap between this and the second cylinder.

It is disadvantageous in this apparatus that the puncture-cutting blade cylinder must be arranged to be high in order that the preceding part of the folded sheet does not get under the entering web of material. A large overall height of the apparatus and thus of the printing machine results, which requires a large and expensive printing works building.

Moreover, in the production of sheet products folded twice longitudinally, the opening of the folding flaps takes place before the cutting of the web in the folding apparatus. The further product guidance, which takes place with the aid of a brush roller, is unreliable and can cause inaccuracies in the second longitudinal fold as well as operating disturbances with machine stoppage times as a result.

It would thus be desirable to provide reliable cutting and folding apparatus which may make possible a lowering of the cost for printing works buildings and may enable production of a good quality second longitudinal fold.

According to the present invention there is pro vided sheet cutting and folding apparatus compris ing an upstream cylinder provided at its circumfer ence with two diametrically opposite first sheet folding members and with two diametrically oppo site sheet cutting and holding devices each compris ing a first cutting element and a row of puncture needles and each substantially equidistantly spaced from the two first folding members, and a down stream cylinder having substantially the same dia meter as the upstream cylinder and provided at its circumference with two diametrically opposite second sheet folding members and with two diamet rically opposite second cutting elements each co operable with a respective one of the first cutting elements and each substantially equidistantly spaced from the two second folding members.

In a preferred embodiment, the cutting and folding apparatus, for example for a rotary roller printing machine, comprises a puncture-cutting blade first cylinder, which is equipped with folding blades and looped around by a web of sheet material, and a folding flap second cylinder, which has two cutting strips each lying opposite the other at the circumference as well as a respective folding flap centrally between these strips. So that the apparatus can have a small overall height and can feed twice longitudinally folded products reliably to the second cylinder, the first cylinder has the diameter of the second cylinder and carries two folding blades each lying opposite the other at its circumference as well as respective cutting blade, which lies centrally between these folding blades and is provided with a row of puncture needles.As a result, it is possible to arrange the first cyiinder at the lower half of the second cylinder without the web of material looped around the first cylinder obstructing the withdrawal of the folded product. The arrangement of associated drawing rollers and a folding funnel can be made correspondingly deep and the overall height of the printing machine kept low. Consequently, investment costs can be lowered in the case of printing works buildings and setting-up of the machine is possible in available low buildings. In apparatus embodying the present invention, cutting of sheets can take place while the folding flaps of the second cylinder are closed, even in the production of folded products with a second longitudinal fold.The products are thereby guided in constrained on the second cylinder, whereby operating disturbances with machine standstill can be avoided and a good quality second longitudinal fold achieved.

An embodiment of the present invention will now be more particularly described by way of example with reference to the accompanying drawing, the single figure of which is a schematic side elevation of cutting and folding apparatus embodying the invention.

Referring now to the drawing, there is shown cutting and folding apparatus comprising a puncture-cutting blade cylinder 1 with a circumference equal to two sheet cut-off lengths and an equally large folding flap cylinder 2. The first cylinder 1 carries two folding blades 3 and 4 lying opposite each other at its circumference as well as respective cutting blades 7 and 8 disposed centrally between the folding blades and provided with a row of puncture needles 5 and 6. The second cylinder 2 has two cutting strips 9 and 10 opposite each other at its circumference as well as respective folding flaps 11 and 12 centrally between these strips.

A material web 13 to be processed is longitudinally folded by means of a folding funnel (not shown) and, after passing drawing rollers 14 and 15, is guided around the cylinder 1. Thereafter, the web 13 is cut by the cutting blade 7 or 8 in conjunction with the strip 9 or 10 on passing between the cylinders 1 and 2. The start of the web following the cut is held by the row of needles 5 or 6 and conducted further on cylinder 1 until, with the formation of a transverse fold by means of the folding blade 3 or 4 and the folding flap 11 or 12, the resulting product 16 is passed over to the cylinder 2. From there, the product 16 is conveyed in horizontal direction indicated by the arrow to equipment for provision of a second longitudinal fold.

Claims (4)

1. Sheet cutting and folding apparatus comprising an upstream cylinder provided at its circumference with two diametrically opposite first sheet folding members and with two diametrically opposite sheet cutting and holding devices each comprising a first cutting element and a row of puncture needles and each substantially equidistantly spaced from the two first folding members, and a downstream cylinder having substantially the same diameter as the upstream cylinder and provided at its circumference with two diametrically opposite second sheet folding members and with two diametrically opposite second cutting elements each cooperable with a respective one of the first cutting elements and each substantially equidistantly spaced from the two second folding members.

2. Apparatus as claimed in claim 1, wherein each first cutting element is a cutting blade and each second cutting element is a counter strip.

3. Apparatus substantially as hereinbefore described with reference to the accompanying drawing.

4. A rotary printing machine provided at a delivery thereof with apparatus as claimed in any one of the preceding claims.