WO1997011823A1

WO1997011823A1 - Rotary die cutting machine

Info

Publication number: WO1997011823A1
Application number: PCT/GB1996/002188
Authority: WO
Inventors: John Anthony Sullivan
Original assignee: COR SERVE Ltd
Current assignee: COR SERVE Ltd
Priority date: 1995-09-28
Filing date: 1996-09-05
Publication date: 1997-04-03
Anticipated expiration: 1998-03-28
Also published as: GB9519747D0; AU6883896A

Abstract

There is disclosed a rotary die cutting machine having an anvil cylinder (11) and annular anvil cover (12) characterised in that the anvil cover (12) hangs loosely over the anvil cylinder (11).

Description

ROTARY DIECUTTING MACHINE

This invention concerns a rotary diecutting machine ofthe kind used in the casemaking industry for cutting blanks of corrugated paper board into shapes which can be folded to form completed cases.

In a rotary diecutting machine the workpiece passes through the nip between two cylinders one of which carries the cutting blades and the other of which comprises an anvil having a cover of a rubber or plastics material, usually polyurethane.

The cover is slidable around and along the anvil cylinder to distribute wear and prolong the life ofthe cover. However, changing the anvil cover is a difficult and time-consuming operation and any measure further to prolong the life of the cover is desirable.

According to the present invention there is provided a rotary diecutting machine having an anvil cylinder and annular anvil cover characterised in that the anvil cover hangs loosely over the anvil cylinder.

In this way the wear surface ofthe anvil cover can be very much greater than that of a conventional cover which is a sliding fit over the anvil cylinder. The cover can freely rotate thus distributing evenly anvil wear, caused by the cutting knives.

The anvil cover may be further located by a guide roller spaced from the anvil cylinder and within the anvil cover. The invention will be further apparent from the following description with reference to the figures ofthe accompanying drawings, which shows, by way of example only, two forms of rotary diecutting machine embodying same.

Ofthe drawings:-

Figure 1 shows a diagrammatic end view of a first form of machine;

Figure 2 shows a diagrammatic end view of a second form of machine; and

Figure 3 shows a perspective view ofthe anvil cover of the machines of Figures 1 and 2.

Referring first to Figure 1, it will be seen that the rotary diecutting machine comprises a driven die mount cylinder 10, having knives 10a and free-wheeling anvil cylinder 11.

The anvil cylinder 11 supports an annular anvil cover 12 comprising an outer surface 13 of polyurethane on a nylon or steel backing 14.

The internal diameter of the cover 12 is significantly greater than the diameter ofthe cylinder 11 so that it hangs loosely from the cylinder 1 1.

In the arrangement of Figure 2, wherein like parts are indicated with like reference numerals the cover 12 is of substantially greater diameter than the cylinder 1 1 and also surrounds a guide roller 15 spaced from the cylinder 1 1 to provide additional support.

It will be understood that the wearing surface of the anvil cover is substantially greater than that of a conventional cover and the life of the cover is commensurate ly greater.

Furthermore, it will be noted that since the cover is not required to fit the anvil cylinder, a single cover size can be used with a wide range of machines having anvil cylinders of different diameters.

As best seen from Figure 3 the anvil covers 12 are formed in two semi¬ circular halves 20 and 21. The mating ends of one half 20 are provided with axially extending dovetail slots 22 adapted to be engaged by screw heads 23 protruding from the mating ends of the other half 21. It will be appreciated that the anvil covers can be manually assembled over the anvil cylinders rapidly and easily without need for any tools simply by positioning the cover halves over the cylinder and sliding them axially together to engage the screw-heads with the dovetail slots.

It will be appreciated that it is not intended to limit the invention to the above example only, many variations, such as might readily occur to one skilled in the art, being possible without departing from the scope thereof.

Claims

1. A rotary die cutting machine having an anvil cylinder and annular anvil cover characterised in that the anvil cover hangs loosely over the anvil cylinder.

2. A rotary die cutting machine according to claim 1 wherein the anvil cover is further located by a guide roller spaced from the anvil cylinder and within the anvil cover.

3. A rotary die cutting machine according to claim 1 or claim 2 wherein the anvil cover has an outer surface of relatively soft material on a backing of relatively hard material.

4. A rotary die cutting machine according to claim 3 wherein the outer surface is of polyurethane.

5. A rotary die cutting machine according to claim 3 or claim 4 wherein the backing is of nylon.

6. A rotary die cutting machine according to any preceding claim wherein the anvil cover is formed from two semi-circular halves having inter engaging protrusions and slots on their mating end surfaces.