WO2013136068A2

WO2013136068A2 - Improvements in or relating to rotary die cutting apparatus

Info

Publication number: WO2013136068A2
Application number: PCT/GB2013/050614
Authority: WO
Inventors: Alan Rae PFAFF; Harald Harsson; Anne Lene GUNNESTAD
Original assignee: Elopak Systems Ag; ORHAGEN, Christine
Priority date: 2012-03-13
Filing date: 2013-03-13
Publication date: 2013-09-19
Also published as: WO2013136068A3; GB201204413D0

Abstract

Apparatus comprising an adjustment assembly including a carriage unit adjustable in a first direction, the carriage unit carrying an adjustment sub- assembly adjustable in a second direction substantially perpendicular to said first direction, the arrangement being such that a path of adjustment of the adjustment assembly is in substantially the same direction as the first direction. Also disclosed is an apparatus for adjusting the distance between respective oppositely facing edges of one or more plate-form members comprising an assembly unit including a plurality of adjustable sub-assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of one or more plate-form members, the sub-assembly units connected to each other by way of at least one adjustment device, whereby operation of the at least one adjustment device adjusts the distance between the respective oppositely facing edges.

Description

IMPROVEMENTS IN OR RELATING TO ROTARY DIE CUTTING APPARATUS

This invention relates to improvements in or relating to the application of flexible steel die plates as used in rotary die cutting applications. Specifically, the invention applies to the precision tensioning and positioning of a flexible steel die plate on a mandrel or cylinder.

Rotary cutting tools and devices are useful for the cutting and forming of materials such as paper, paperboard, cardboard, plastic, film, metal foil, thin sheet metal, etc. Typically, such thin materials are positioned between a pair of die plates which are mounted on co-acting rotating cylinders. The advantages of rotary die processing of materials are, generally speaking, high speed and high volume production. In order to achieve the desired speed and quality of the parts produced by rotary die cutting utilizing flexible steel die plates, it is imperative that the die plates are properly affixed and aligned with respect to cylinders. Uniform tension and precision positioning of the die plates are also required. In this respect, tension units are used to mount the flexible die plates onto the cylinder without having to use screws or welding. Such tension units are designed to fine tune the position of the die plate ends relative to each other.

Various methods of affixing die plates to cylinders are known and include magnetic means, screws and bolts, eccentric cam assemblies, and related concepts. However, cost, and functional deficiencies have made the currently used methods impractical and or cost prohibitive.

US7000522 discloses a rotary cutting tool with easy to adjust rotary die plates comprising a rotary die cylinder, a die plate adjustably mounted to the rotary die cylinder, an external eccentric mounted on the rotary die cylinder having a first axis of rotation with respect to the cylinder and having a central opening offset from the first axis, and an internal eccentric mounted in the central opening. Rotation of the external eccentric urges the internal eccentric to move with respect to the cylinder, and the die plate moves in response to motion of the internal eccentric.

According to a first aspect of the present invention, there is provided apparatus comprising an adjustment assembly including a carriage unit adjustable in a first direction, said carriage unit carrying an adjustment sub-assembly adjustable in a second direction substantially perpendicular to said first direction, the arrangement being such that a path of adjustment of the adjustment assembly is in substantially the same direction as said first direction.

According to a second aspect of the present invention, there is provided a method of adjusting an adjustment assembly comprising adjusting the adjustment assembly in a first direction and adjusting the adjustment assembly in a second direction substantially perpendicular to said first direction, wherein the adjustment in the first and second directions is performed in an adjustment path arranged in substantially the same direction as said first direction. Owing to these aspects of the present invention, adjustment of an item to be attached to the adjustment assembly can be relatively quickly and easily made from the direction of one adjustment path.

Preferably, the adjustment assembly is mounted to an object, which preferably is a rotary die cylinder of a rotary die cutting tool about which a die plate is to be attached by way of the adjustment assembly. The die plate is then adjusted in the first and second directions relative to the die cylinder by way of the adjustment assembly. Advantageously, the adjustment assembly is a sliding block arrangement in which the carriage unit and the adjustment sub-assembly carried thereby are mounted in a mounting block which has a curvature to its upper surface to correspond to the curvature of the outer surface of the die cylinder. Preferably, the adjustment sub-assembly comprises adjustment elements which are adjacent and slidably engage each other.

In addition, in the path of adjustment there are, advantageously, two adjustment access ports adjacent each other that preferably are accessible from the outwardly facing surface of the die cylinder about which the die plate is wrapped. Thus there are corresponding holes in the die plate to allow access to the ports in the adjustment path.

According to a third aspect of the present invention, there is provided apparatus for adjusting the distance between respective oppositely facing edges of one or more plate-form members comprising an assembly unit including a plurality of adjustable sub-assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of one or more plate-form members, said sub-assembly units connected to each other by way of at least one adjustment device, whereby operation of the at least one adjustment device adjusts the distance between the respective oppositely facing edges.

According to a fourth aspect of the present invention, there is provided a method of adjusting the distance between respective oppositely facing edges of one or more plate-form members comprising mounting the plate-form member to an object and operating at least one adjustment device which connects a plurality of sub-assembly units of an assembly unit, said plurality of assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of one or more plate-form members. Owing to these aspects, it is possible to enhance the ability to align the end edge regions of a plate member wrapped around an object, particularly when the assembly unit is located at a mid-region along the length of the object and between other laterally outward locations where the plate member is also attached to the object. Advantageously, the adjustment device is in the form of an opposing thread adjustment screw, which has regions, corresponding to the sub-assembly units, with opposite threads, such that adjusting the screw in one direction causes movement of the sub-assembly units in opposite directions, i.e. either towards or away from each other.

The one or more plate-form members are, advantageously a die plate for wrapping around a die cylinder of a rotary die cutting tool, as mentioned above.

The preferred arrangement has two sliding blocks as the sub-assembly units which are slidably mounted in the assembly unit which itself is mounted to the rotary die cylinder.

The assembly unit is advantageously an intermediate adjustment arrangement located between two adjustment assemblies capable of adjusting the position of the facing plate edges in first and second directions relative to the die cylinder.

In order that the present invention can be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings in which:-

Figure 1 is a perspective transparent view of a mounting block with an adjustment assembly therein,

Figure 2 is a plan view from above of the mounting block of Figure 1 ,

Figure 3 is a cross section along the line Ill-Ill of Figure 2,

Figure 4 is a cross section along the line IV-IV of Figure 2, Figure 5 is a diagrammatic cross-section of a die cylinder having an intermediate adjustment unit, and

Figure 6 is a schematic view of the detail of the intermediate adjustment unit of Figure 5.

A rotary cutting tool conventionally comprises a rotary die cylinder of substantially circular cross-section and having an axis of rotation, a pair of cylinder side walls and an outer curved surface over around which a die plate is to be wrapped and rigidly attached to the die cylinder, and subsequently accurately positioned relative to the cylinder by way of adjustable means attached to the cylinder and the plate.

Referring to Figures 1 to 4, an adjustment assembly 4 (also known as a tension unit) is mounted inside a mounting block 6, which is generally rectangular in plan view. The mounting block has respective opposite front and back portions 6a and 6b and respective opposite side portions 6c and 6d with an internal chamber 7 for receiving the adjustment assembly 4. Two or more mounting blocks 6 are mountable in respective correspondingly shaped recesses on the curved outer surface of a rotary die cylinder of a rotary die cutting tool at lateral edge regions thereof. The upper surface 8 of the mounting block 6 has a curvature to correspond to that of the surface of the die cylinder. The mounting block also includes a throughhole 10 for receiving a bolt 12 to secure the block 6 to the die cylinder, the die cylinder including at its surface a threaded bore to receive the threaded shank of the bolt 12. The bolt 12 not only prevents the block 6 from falling out of its recess but also prevents any x-axis motion of the block 6 within its recess, that is to say motion substantially parallely to the axis of rotation of the die cylinder.

The block 6 further comprises a movement restricting window 14 in its upper surface 8 and a further throughhole 16 to receive a further bolt 18 for attaching the die plate to the mounting block 6. The die plate preferebaly has a countersunk hole for receiving the head of the bolt 18.

The adjustment assembly 4 comprises a carriage unit 20, which has a channel 22 thereacross bounded along its sides by opposing wall surfaces 24. Tightly but slidingly received between the wall surfaces 24 is an adjustment sub-assembly 26 which comprises adjustment elements 28a and 28b located adjacent each other along respective bearing surfaces, there being no special machining of parts required in order that one part might fit within or overlap with another part. Thus the carriage unit 20 wholly carries the sub-assembly 26.

The adjustment element 28a includes an upper block attached to a lower block. The lower block is located between and contacts both walls 24 of the carriage unit 20 for slidable movement therebetween. The upper block extends from an upper surface of the lower block into the window 14 of the mounting block 6. The upper surface of the upper block does not extend beyond the upper surface 8 of the block 6 and also has a curvature to correspond with the curvature of the die cylinder. The sub-element 28a also includes a throughhole 30 for receiving a third bolt 32 for fixing the die plate to the adjustment assembly 4. As with the bolt 18, the die plate has a corresponding hole which is countersunk to receive the head of the bolt 32.

The respective opposite end edges of the die plate, once wrapped around the die cylinder meet almost in a face-to-face relationship and the region where they face each other is between the bolts 18 and 32. In this way, one end region of the plate is rigidly attached to the mounting block 6 and thus the die cylinder whilst the other end region is adjustable by way of the adjustment assembly 4.

The adjustment element 28b is a block of substantially the same thickness as the element 28a but does not occupy the whole width of the channel 22 between the walls 24, but instead is connected to an adjustment device 34 in the form of an adjustment screw. The screw 34 is attached to the element 28b by way of a pair of internal fixing pins 36 insertable through holes 38 in the upper surface of the element 28b in order to engage a neck region of one end region of the screw 34 inwardly of a head region. The screw 34 extends from the element 28b and into a bore 40 at one end of the carriage unit 20. The mounting block 6 has a corresponding co-linear bore 42 in its front portion 6a. The front portion 6a further comprises, adjacent the bore 42 a further bore 44 for receiving a further adjustment device to abut the corresponding front surface of the carriage unit 20, such as a set screw 46 (as shown in Figures 1 to 3).

The bearing surfaces of the adjustment elements 28a and 28b whereby one contacts the other are correspondingly angled, or have correspondingly angled portions, in a wedge formation in which the angle of the surfaces is in the range of substantially 10° to substantially 20°, and most advantageously around 15°.

Adjustment of the set screw 46 adjusts the position of the carriage unit 20 in a first direction within the chamber 7 and within the limits of the window 14, namely in the y-axis direction, i.e. around the axis of rotation of the die cylinder. Adjustment of the screw 34 causes the adjustment element 28b to move in the y- axis direction and thus bring about motion of the element 28a in a second direction substantially perpendicular to the first direction, namely in the x-axis direction, i.e. substantially parallely to the axis of rotation of the die cylinder within the channel 22 and within the confines of the window 14. The co-linear bores 40 and 42 and the bore 44 define an adjustment path P, which, for both the adjustment in the x- and y-axes, is the same direction. Access to the bores 40, 42 and 44 is made from the outer curved surface of the die cylinder and its correspondingly attached die plate which have corresponding bores which accurately align with the bores 40, 42 and 44 to form respective access ports through which an adjustment tool can operate in the path P to bring about adjustment as desired. The single path P has the significant advantage that adjustment can be made from the outer facing curved surface of the die cylinder/plate and no access to the side regions of the die cylinder is required and/or adjustments do not have to be made in a plurality of adjustment paths, which is relatively very time-consuming.

Referring to Figures 5 and 6, the die cylinder referenced 46 includes in a recess, at a central region along its length and between two laterally disposed adjustment assemblies 4, an intermediate adjustment unit 48 in the form of an insertable assembly block. The unit 48 comprises two slidably adjustable sub-assembly units or blocks 48a and 48b connected by way of another adjustment device 50, which is, advantageously, an opposing threaded adjustment screw which extends from one end region of the unit 48 to the opposite end region of the unit 48, one or both of the end regions having a bore which opens to the external surface of the unit 48. The screw 50 has separate regions of opposing threads, which regions correspond to respective ones of the sub-assembly units 48a and 48b. Each sub-assembly 48a and 48b has in its top surface a bore therein, preferably threaded, to receive the shank of a fixing pin in the form of, for example, a correspondingly threaded bolt 50 in order to fix the die plate referenced 52 to the unit 48. Again, the plate 52 has corresponding countersunk holes or bores to receive the heads of the bolts 50.

The sub-assembly units 48a and 48b are divided about a mid-region of the unit 48 which corresponds to a region 54 where the facing end edges of the plate 52 are located, so that the arrangement is such that one end edge region of the plate 52 is fixed to one sub-assembly unit and the other end edge region is fixed to the other sub-assembly unit. In addition, each sub-assembly unit is enclosed by the unit 48 as a whole and has bearing surfaces with the internal surfaces of the chambers of the unit 48 in which they are located. In this way, the facing edge regions of the plate 52 can be adjusted, again, in the adjustment path P. The die cylinder 46 and the plate 52 have corresponding bores 54 and 56 respectively which accurately align with the opening on the external surface of the unit 48 to form an access port to the adjustment screw 50.

In this way, when the adjustment screw is adjusted in the path P with a suitable tool 58 the facing end edges of the plate 52 in that region can be made to move closer together or further away from each other in the y-axis direction, i.e. around the axis of rotation of the die cylinder 46.

Claims

1 . Apparatus comprising an adjustment assembly including a carriage unit adjustable in a first direction, said carriage unit carrying an adjustment subassembly adjustable in a second direction substantially perpendicular to said first direction, the arrangement being such that a path of adjustment of the adjustment assembly is in substantially the same direction as said first direction.

2. Apparatus according to claim 1 , wherein the adjustment assembly is mounted to a rotary die cylinder of a rotary die cutting tool about which a die plate is to be attached by way of the adjustment assembly.

3. Apparatus according to claim 2, wherein the die plate is adjustable in the first and second directions relative to the die cylinder by way of the adjustment assembly.

4. Apparatus according to any preceding claim, wherein the adjustment assembly is a sliding block arrangement in which the carriage unit and the adjustment sub-assembly carried thereby are mounted in a mounting block which has a curvature to its upper surface to correspond to the curvature of the outer surface of the die cylinder.

5. Apparatus according to claim 4, wherein the mounting block has respective opposite front and back portions and respective opposite side portions with an internal chamber for receiving the adjustment assembly.

6. Apparatus according to claim 4 or 5, wherein the mounting block further comprises a movement restricting window in its upper surface.

7. Apparatus according to any preceding claim, wherein the adjustment sub- assembly comprises adjustment elements which are adjacent and slidably engage each other.

8. Apparatus according to any one of claims 2 to 7, and further comprising, in the path of adjustment, adjustment access ports adjacent each other accessible from the outwardly facing surface of the die cylinder about which the die plate is wrapped.

9. Apparatus according to claim 9, wherein the the die plate has corresponding holes to allow access to the ports in the adjustment path.

10. Apparatus according to any preceding claim, wherein the carriage unit has a channel thereacross bounded along its sides by opposing wall surfaces.

1 1 . Apparatus according to claim 10, wherein the adjustment sub-assembly is tightly but slidingly received between the opposing wall surfaces.

12. Apparatus according to any preceding claim, wherein the adjustment subassembly comprises first and second adjustment elements located adjacent each other along respective bearing surfaces.

13. Apparatus according to claim 12, wherein the respective bearing surfaces are correspondingly angled, or have correspondingly angled portions, in a wedge formation.

14. Apparatus according to claim 13, wherein the angle of the surfaces is in the range of substantially 10° to substantially 20°

15. Apparatus according to claim 13 or 14, wherein the angle of the surfaces is around 15°.

16. Apparatus according to any one of claims 12 to 15 as appended to claim

10. wherein the first adjustment element includes an upper block attached to a lower block, and wherein the lower block is located between and contacts the opposing wall surfaces for slidable movement therebetween.

17. Apparatus according to claim 1 6 as appended to claim 6, wherein the upper block extends from an upper surface of the lower block into the window.

18. Apparatus according to any one of claims 12 to 1 7 as appended to claim 5, wherein the second adjustment element is a block of substantially the same thickness as the first element but does not occupy the whole width of the channel between the opposing wall surfaces and is connected to an adjustment device which extends through a bore in the front portion of the mounting block.

19. Apparatus according to claim 18, and further comprising, adjacent the bore a further bore for receiving a further adjustment device to abut the corresponding front surface of the carriage unit.

20. Apparatus according to any one of claims 2 to 19, and further comprising, for adjusting the distance between respective oppositely facing edges of the die plate, an assembly unit including a plurality of adjustable sub-assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of the die plate, said sub-assembly units connected to each other by way of another at least one adjustment device, whereby operation of the at least one adjustment device adjusts the distance between the respective oppositely facing edges.

21 . Apparatus according to claim 20, wherein operation of the at least one adjustment device is in said path of adjustment.

22. A method of adjusting an adjustment assembly comprising adjusting the adjustment assembly in a first direction and adjusting the adjustment assembly in a second direction substantially perpendicular to said first direction, wherein the adjustment in the first and second directions is performed in an adjustment path arranged in substantially the same direction as said first direction.

23. A method according to claim 22, and further comprising, prior to the adjusting, mounting the adjustment assembly to a rotary die cylinder of a rotary die cutting tool about which a die plate is to be attached by way of the adjustment assembly.

24. A method according to claim 23, and forming in the die cylinder through holes opening on the curved outer surface of the cylinder and in said adjustment path.

25. A method according to claim 24, and further comprising forming through holes in the die plate corresponding to those through holes of the cylinder and in the adjustment path.

26. A method according to any one of claims 22 to 25, and further comprising operating an adjustment device for adjustment in the first direction.

27. A method according to claim 26, and further comprising operating a further adjustment device for adjustment in the second direction.

28. A method according to any one of claims 23 to 27 of adjusting the distance between respective oppositely facing edges of die plate comprising mounting the die plate to the die cylinder and operating at least one adjustment device which connects a plurality of sub-assembly units of an assembly unit, said plurality of assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of the die plate

29. A method according to claim 28, wherein operation of the at least one adjustment device is in said adjustment path.

30. Apparatus for adjusting the distance between respective oppositely facing edges of one or more plate-form members comprising an assembly unit including a plurality of adjustable sub-assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of one or more plate-form members, said sub-assembly units connected to each other by way of at least one adjustment device, whereby operation of the at least one adjustment device adjusts the distance between the respective oppositely facing edges.

31 . Apparatus according to claim 30, wherein the adjustment device is an opposing thread adjustment screw.

32. Apparatus according to claim 30 or 31 , wherein the one or more plate-form members is a die plate for wrapping around a die cylinder of a rotary die cutting tool.

33. Apparatus according to any one of claims 30 to 32, wherein the subassembly units comprise two sliding blocks which are slidably mounted in the assembly unit.

34. Apparatus according to any one claims 30 to 33, wherein the assembly unit is an intermediate adjustment arrangement located between two adjustment assemblies capable of adjusting the position of the facing plate edges in first and second directions relative to the die cylinder.

35. Apparatus according to claim 34 as appended to claim 32, wherein the assembly unit is mounted in a recess of the die cylinder.

36. Apparatus according to any one of claims 32 to 35, wherein the die cylinder and the die plate have corresponding bores which align with an opening on the external surface of the assembly unit to form an access port to the adjustment device.

37. A method of adjusting the distance between respective oppositely facing edges of one or more plate-form members comprising mounting the plate-form member to an object and operating at least one adjustment device which connects a plurality of sub-assembly units of an assembly unit, said plurality of assembly units divided about a mid-region of the assembly unit corresponding to the region of the respective oppositely facing edges of one or more plate-form members.

38. A method according to claim 37, wherein the adjustment device is an opposing thread adjustment screw.

39. A method according to claim 37 or 38, wherein the one or more plate-form members is a die plate for wrapping around a die cylinder of a rotary die cutting tool.

40. A method according to any one of claims 37 to 39, wherein the sub- assembly units are slidably mounted within the assembly unit.

41 . A method according to any one claims 37 to 40, wherein the assembly unit is an intermediate adjustment arrangement located between two adjustment assemblies capable of adjusting the position of the facing plate edges in first and second directions relative to the die cylinder.

42. A method according to claim 41 as appended to claim 39, and further comprising, prior to said adjusting, mounting the assembly unit in a recess of the die cylinder.

43. Apparatus according to any one of claims 39 to 42, and forming corresponding bores in the die cylinder and the die plate which align with an opening on the external surface of the assembly unit to form an access port to the adjustment device.