GB2337224A

GB2337224A - Die cutting apparatus

Info

Publication number: GB2337224A
Application number: GB9807975A
Authority: GB
Inventors: Mark John Whitehouse
Original assignee: RALEGH Ltd
Current assignee: RALEGH Ltd
Priority date: 1998-04-16
Filing date: 1998-04-16
Publication date: 1999-11-17
Also published as: GB9807975D0

Abstract

A die cutting apparatus 1 comprises a chase plate 2 at or adjacent one side 4 of which is mounted a clamp having a bar 7, movable inwardly and outwardly of the chase plate 2 between respective clamping and release positions. The bar 7 in its respective clamping and release positions and in use of the apparatus 1, is arranged to clamp and release an adjacent side (31, Figure 2) of a cutting die (30, Figure 2) to and from the chase plate 2. The bar 7 may be movable by use of a tool (50, Figure 2) and the plate 2 may be further provided with retaining means 20, a locating notch 21 and with a magnetic element assembly (45, Figure 3) to hold the die in place.

Description

1 11 2337224 DIE CUTTING APPARATUS

DESCRIPTION

This invention relates to die cutting apparatus and various aspect thereof, the apparatus being for use in cutting and creasing sheet material, such as corrugated board, to provide a cut and creased blank for subsequent erection into a container.

Known die cutting apparatus of this type comprises a chase plate, usually of a ferrous material, such as steel, to which is detachably securable an exchangeable, generally planar cutting die by means of bolts or screws extending through respective ones of a predetermined array of holes in the chase plate and screwed into respective ones of a corresponding array of threaded inserts embedded in the base plate of the cutting die, which plate is usually made of wood, such as plywood, and carries the cutting and creasing blades of the die.

To exchange the cutting die for another having cutting and creasing blades of a different configuration to the first, requires the securing bolts or screws to be removed from the first die and the underside of the chase plate and then to be replaced in the other die, from the underside of the chase plate, thereby securing the die to the chase plate. These procedures are both time consuming and labour intensive and, thus, undesirable.

Accordingly, it is an object of the present invention to provide die cutting apparatus which overcomes, or at least substantially reduces, the 1 01.

- 2 disadvantages discussed above in relation to the prior art die cutting apparatus, as well as other disadvantages associated therewith.

A first aspect of the invention resides in die cutting apparatus comprising a chase plate at or adjacent one side of which is mounted means movable inwardly and outwardly of the chase plate between respective clamping and release positions and which, in its respective clamping and release positions and in use of the apparatus, is arranged to clamp and release an adjacent side of a cutting die to and from the chase plate.

Preferably, the clamping/release means is a bar or bars which extends at least partially along one side of the chase plate and which may be biassed into the clamping position with respect to the chase plate, for example, by means of at least one compression spring which may act between a raised edge of the chase plate and the bar(s). Also, the or each bar may be mounted upon at least one guide engaging with, say, a raised edge of the chase plate. In an embodiment of the die cutting apparatus in accordance with the first aspect of the invention, the at least one guide comprises a rod having one end secured, for example, screwed, to the or each clamping/release bar and having its other end slidably received within a correspondingly-dimensioned bore in the raised edge of the chase plate. This arrangement permits the clamping/release bar(s) to be retrofitted to an existing chase plate.

When the or each clamping/release bar is spring biassed into its clamping position with respect to the chase plate, such bias is usually considerable, in which case, it may be necessary to use a lever or other suitable means to move the or each bar from its clamping position into its release position.

In a preferred embodiment, such lever means comprises an inverted, generally T-shaped tool having, at its upper end, a lever bar and, at its lower end, a pair of spaced, projecting lugs which are arranged to engage in respective recesses in the or each clamping/release bar and the chase plate, preferably within a raised edge of the latter.

The recess in the or each bar is preferably a blind bore, whilst that in, say, the raised edge of the chase plate is a slot having at one end an indent for receiving the corresponding lug of the tool therein when the or each c lamping/re lease bar is in its release position, to retain the or each bar in that position whilst, say, one cutting die is replaced with another on the chase plate.

The raised edge of the chase plate is preferably provided by a frame extending around the periphery thereof.

Also, the inventive apparatus may comprise retaining means preferably on the side of the chase plate opposite that with which the clamping/release means is associated. - Such retaining means may comprise a plurality of clips which are movable between respective operative and inoperative positions, for retaining an adjacent side of the base plate of a cutting die on the chase plate and for allowing that adjacent base plate side to be removed f rom the chase plate when the other side of the die base plate is released by the clamping/release means. Such retaining means is preferably manually movable between its operative and inoperative positions, although a similar arrangement to that for moving the clamping/release means between its clamping and release positions, may be used. Similarly also, the retaining means may be mounted upon a raised edge of the chase plate, for example, a peripheral frame thereof.

When the chase plate is made of a ferrous material, such as steel, the main area of the base plate of the cutting die may be secured detachably to the generally central area of the chase plate by magnetic means, for example, a plurality of magnetic elements arranged in an array and mounted to, such as embedded in, the cutting die base plate. In this manner, substantially the whole of the area of the die base plate can be maintained in close confronting contact with the chase plate.

Accordingly, a second aspect of the invention resides in a magnetic element assembly for use in die cutting apparatus, such as that defined above in accordance with the first aspect of the invention, the assembly comprising a body, preferably of a metallic material, which is shaped and dimensioned to fit within a correspondingly-shaped and dimensioned aperture in the base plate of a cutting die and which includes a magnet and means arranged to permit the body to be fitted removably within the cutting die base plate aperture.

Said means preferably comprises at least one - 5 member mounted in and biassed outwardly of the body for engaging a correspondingly-shaped recess, such as an annular groove, in the wall of the aperture of the cutting die base plate. Al ternatively, such a recess may be provided in the inner wall of a sleeve received in the cutting die base plate aperture, in which case, the sleeve can constitute part of the magnetic element assembly.

In a preferred embodiment of the inventive magnetic element assembly to be described in more detail hereinbelow, the body is circular in section with a central bore at one end of which the magnet, such as a disc magnet, is located. The central bore may be provided with an enlarged diameter portion defining therein an annular shoulder arranged to receive an end of a tool for removing the body, and hence the magnet, from a correspondingly-shaped aperture in the cutting die base plate in which the magnetic element assembly is fixed during use. The body is preferably a push-fit within such an aperture, such that the or each outwardly biassed member is engaged within the correspondingly- shaped recess, to retain the magnetic element assembly within the aperture during use but enabling the body to be removed from the aperture using, for example, the removal tool mentioned above.

The end of the tool for removing the body f rom. the cutting die base plate aperture is preferably provided with a foot for engaging, say, the shoulder within the central body bore, to facilitate removal of the body from the cutting die base plate aperture.

In order that the invention may be more fully understood, preferred embodiments in accordance therewith will now be described by way of example and with reference to the accompanying drawings in which:

Figure 1 is a perspective view of die cutting apparatus in accordance with the first aspect of the invention; Figure 1A is a section of the die cutting apparatus of Figure 1 along the line A-A; Figure 2 is a perspective view of cutting die apparatus shown in Figures 1 and 1A, with a cutting die about to be positioned thereon; Figure 2B is a section of the die cutting apparatus shown in Figure 2 with the cutting die positioned initially thereon, along the line B-B; Figure 3 is a perspective view of die cutting apparatus shown in Figures 1 and 2 with the cutting die positioned and retained thereon; Figure 3C is a section along the line C-C of Figure 3; Figure 4 is an enlarged perspective view of a portion of the die cutting apparatus shown in Figure 1, along with an associated tool; Figure 5 is a sectional view of a magnetic element assembly in accordance with the second aspect of the invention, installed in the base plate of a cutting die; and Figure 6 is a perspective view of a body of the assembly shown in Figure 5, along with an associated removal tool.

is Referring f irstly to Figures 1 and 1A of the drawings, die cutting apparatus, indicated generally at 1, in accordance with the f irst aspect of the invention defined above, comprises a steel rectangular chase plate 2 having a raised, rectangular frame extending around the periphery thereof. The f rame comprises a f ront edge 3, a rear edge 4 which is opposite and parallel to the front edge 3, and a pair of opposed, parallel side edges 5 and 6.

Mounted on the inner face of the rear edge 4 of the frame of the chase plate 2 is a generally L-shaped bar 7 which extends partially along the length of the rear edge 4 and parallel thereto.

The L-shaped bar 7 is so-mounted for movement inwardly and outwardly of the chase plate 2 between respective clamping and release positions, as will be described in more detail hereinbelow.

The bar 7 is mounted to the rear edge 4 of the chase plate frame by means of a pair of spaced guide rods 8 adjacent respective opposed ends thereof.

As can be seen f rom Figure 4, each guide rod 8 (only one shown) has a threaded end 9 which is screwed into a threaded bore 10 in the bar 7. The other end 11 of each rod 8 is slidably received within a correspondinglydiametered bore 12 in the rear edge 4 of the f rame of the chase plate 2, with an enlarged head 13 being slidably received within an enlarged 8 diameter portion 14 of the bore 12.

il, In the clamping position of the L-shaped bar 7, the head 13 of the guide rod 8 abuts a shoulder defined between the larger diameter portion 14 and the bore 12.

The cl amping/re lease bar 7 is biassed into its clamping position, as shown in Figures 1, 3 and 4, by means of three compression springs 15 which act between the rear edge 4 of the chase plate frame and the clamping/release bar 7 As shown again in Figure 4, the ends of each compression spring 15 are received in respective blind bores 16, 17 in the rear edge 4 and the bar 7.

As the bias exerted upon the clamping/re lease bar 7 in the clamping position thereof is considerable, it is necessary to use a tool, indicated generally at 50, to enable the bar 7 to be moved f rom its clamping position into its release position.

That tool 50 is shown in detail, again in Figure 4, as being of inverted, generally T-shape. At the upper end 51 of the tool 50 is provided a lever bar 52 and, at its lower end 53, a pair of spaced, downwardly projecting lugs 54, 55 for engaging in respective recesses 56, 57 in the rear edge 4 of the chase plate frame and the clamping/release bar 7. The recess 56 is in the form of a slot having at one end thereof an indent 58 for receiving the corresponding lug 54 of the tool 50 therein when the bar 7 is in its release position, to retain the bar 7 in that position.

As can be seen from Figure 2, two such tools 50 are provided.

In order to move the clamping/release bar 7 from its clamping position, as shown in Figure 4, into its release position, as shown in Figure 2, the lugs 54 and 55 are inserted into the respective recesses 56, 57 in the rear edge of the chase plate frame and the bar 7, with the lug 54 being located at the end of the slot recess 56 remote from the end at which the indent 58 is provided. The lever bar 52 is then rotated manually in the direction of the arrow A, such that the lug 54 is moved along the slot recess 56, with the lug 55 acting as a pivotal axis for the tool 50. As a consequence, the clamping/release bar 7 is moved outwardly with respect to the chase plate 2 towards the rear edge 4 of the chase plate f rame, until it reaches its release position, at which stage the lug 54 is received in the indent 58, to retain the bar 7 in that release position. As the lug 54 moves into the indent 58, it, and as a consequence the whole tool 50, undergoes a slight downward movement.

To move the clamping/release bar 7 from its release position into its clamping position, operation of the tool 50 is reversed, with its lever bar 52 being rotated in the opposite direction to that of the arrow A.

On the f ront edge 3 of the f rame of the chase plate 2 is provided a pair of spaced retaining clips 20 which are slidably movable inwardly and outwardly with respect to the chase plate 2 between respective operative and inoperative positions, as will be described in more detail hereinbelow.

In operation of the die cutting apparatus 1 described above, the clamping/release bar 7 is initially in its clamping position, as shown in Figures 1 and 1A. Also, the retaining clips 20 are in their inoperative positions located outwardly of the chase plate 2.

AS shown in Figure 2, the clamping/release bar 7 is moved from its clamping position into its release position, as described above and using the pair of tools 50.

A cutting die, indicated generally at 30, is then moved in position above the chase plate 2 and the rear edge 31 of the base plate 32 of the cutting die 30 is located beneath the upper lip 7', with the opposed front edge 33 of the base plate 32 abutting the inner face of the front edge 3 of the chase plate frame, as shown in Figure 2B.

In this manner, the f ront edge 3 of the chase plate frame provides a datum line for the cutting die 30.

Proper location of the front edge 33 with respect to the inner face of the front edge 3 of the chase plate frame is provided by an inwardly projecting lug 21 on that inner face and a corre spondingly- shaped recess 34 provided in front edge 33 of the base plate 32 of the cutting die 30.

Then, the retaining clips 20 on the front edge 3 of the chase plate frame are slid inwardly thereof, such that they engage over the front edge 33 of the base plate 32 of the die 30, whilst the bar 7 is moved I,- is from its release position, as shown in Figure 2, into its clamping position as shown in Figures 3 and 3C, using the pair of tools 50. In this manner, the lip 7' of the bar 7 engages over the rear edge 31 of the base plate 32 of the cutting die 30, such that the bar 7 clamps the die 30 firmly in position upon the chase plate 2.

As can be seen from Figures 2, 2B, 3 and 3C, the base plate 32 of the cutting die 30 is provided with five apertures 40 therethrough. one aperture 40 is at the centre of the base plate 32 of the die 30, whilst there is another aperture 40 adjacent each corner thereof.

As shown in Figures 2B, 3C and 5, each aperture 40, which is circular in section, is provided with a circular sleeve 41 secured therein and having an annular groove 42 at its upper region.

In accordance with the second aspect of the invention defined above, the sleeve 41 constitutes part of a magnetic element assembly, indicated generally at 45 in Figures 3, 3C and 5. That assembly 45 also comprises a generally circular body 44 of steel having an annular flange 43 engaging the top edge of the sleeve 41. A central bore 46 extends through the body 44 and has a larger diameter portion 47 defining an annular shoulder 48. A strong disc magnet 49 (neodymium iron boron) is friction fitted or adhered to a non-magnetic ring 66 also friction-fitted or adhered into a recess 67 in the base of the body 44. The magnet 49 may be removed from the recess 67 by screwing a suitably threaded rod (not shown) into a threaded hole 60 in a reduced diameter portion 61 of the bore 46.

Provided in each of four radial ly- extending bores 62 in the body 44, is a compression spring 63 which biasses radially outwardly of the body 44 a spherical member 64 which is retained in the bore 62 by means of an outer lip 65 but which has a portion protruding outwardly of the bore 62 and received in the annular groove 42 of the sleeve 41.

The lower surf ace of both the body 44 and the magnet 49 is generally flush with the lower surface of the base plate 32 of the cutting die 30, with the annular groove 42 and outwardly protruding portion of the spherical member 64 received therein providing a consistent height, for retaining the magnet 41 flush with the surface of the chase plate 2.

In this manner, and because the base plate 32 of the cutting die 30 which is usually made of 15 mm plywood, is not absolutely flat, the strong magnetic attraction between the magnets 49 and the steel chase plate 2, eliminates, or at least substantially reduces, any fluctuations in the required planar form of the die base plate 32.

Thus, when the cutting die 30 has been placed upon and retained in position with respect to the chase plate 2, as described above and as shown in Figure 3 and 3C, the bodies 44 of the magnetic element assemblies 45 are push-fitted into their respective apertures 40 in the die base plate 32, to retain substantially the whole of the area of that base plate 32 in engaging contact with the surface of the chase plate 2.

1 13 - Each body 44 of the magnetic element assembly 45 can be removed from its corresponding aperture 40 in the base plate 32 of the die 30 by means of a tool 70, as shown in Figure 6.

That tool 70 comprises an operating arm 71 at the lower end of which is provided a foot 72 which can be located beneath the annular shoulder 48 of the bore 46, 47 of the body 44. Then, the body 44 can be levered from the aperture 40 using the tool 70.

one major advantage of the presently- inventive apparatus is that the clamping/release bar 7, and its associated components, can be retrofitted to the raised frame of an existing chase plate 2. if, however, the thickness of, say, the rear edge 4 of that chase plate frame is insufficient to mount thereon a single clamping release bar 7, then two or more shorter bars may be provided for individual movement between respective clamping and release positions using, for example, the tool 50 described above.

In known die cutting apparatus, the cutting die is f ixed to the steel chase plate by an operator climbing underneath the chase plate to fix screws or bolts up through the array of holes into the base plate of the die, as discussed above. The chase plate is then rotated through 180 and slid into the side of the die cutting section of a die cutting machine, which means that the cutting die and its cutting and creasing blades are facing downwardly. Therefore, it is important that the cutting die is fixed firmly to the chase plate, to prevent the die from falling from the chase plate and causing severe damage to the die cutting machine. It is further important that substantially the whole of the area of the base plate of the cutting die is in engaging contact with the surf ace of the chase plate 2, which is not always provided by conventional die cutting apparatus.

Thus, it is to be appreciated that the presentlyinventive die cutting apparatus overcomes, or at least substantially reduces, those disadvantages associated with conventional die cutting apparatus, by means of the c lamping/re lease bar(s) 7 and the magnetic element assemblies 45. Also, because each magnetic element assembly 45 is retained securely, but nevertheless detachably, in its aperture 40 in the base plate 32 of the die 30, it cannot fall therefrom during use of the apparatus within a die cutting machine, thereby preventing any damage thereto.

Accordingly, the various aspects of the invention reduce die cutting machine set up time, is user friendly in that an operative does not have to climb underneath the chase plate to insert or remove the die-retaining screws and the need for a side chase loader is eliminated.

A.'..

1.1> -

Claims

1. A die cutting apparatus comprising a chase plate at or adjacent one side of which is mounted means movable inwardly and outwardly of the chase plate between respective clamping and release positions and which, in its respective clamping and release positions and in use of the apparatus, is arranged to clamp and release an adjacent side of a cutting die to and from the chase plate.

2. An apparatus according to claim 1, wherein the clamping/release means is a bar or bars which extends at least partially along one side of the chase plate.

3. An apparatus according to claim 2, wherein biasing means is arranged to bias the bar or bars into the clamping position with respect to the chase plate.

4. An apparatus according to claim 3, wherein the biasing means comprises at least one compression spring which acts between a raised edge of the chase plate and the bar(s).

5. An apparatus according to any of claims 2, 3 or 4, wherein the or each bar is mounted upon at least one guide.

6. An apparatus according to claim 5, wherein the guide engages a raised edge of the chase plate.

7. An apparatus according to claim 5 or 6, wherein the at least one guide comprises a rod having one end secured, for example, screwed, to the or each clamping/release bar and having its other end slidably received within a correspondingly-dimensioned bore in the raised edge of the chase plate.

C c 0000 c C, 0 0 lid -

8. An apparatus according to claim 4 or 5, when dependent on claim 4, 6 and 7, wherein a lever, or other suitable means, moves the or each bar from its clamping position into its release position.

9. An apparatus according to claim 8, wherein the lever means comprises an inverted, generally T-shaped tool having, at its upper end, a lever bar and, at its lower end, a pair of spaced, projecting lugs which are arranged to engage in respective recesses in the or each clampingfrelease bar and the chase plate,

10. An apparatus according to claim 9, wherein the recesses of the chase plate are situated within a raised edge thereof

11. An apparatus according to claim 10, wherein the raised edge of the chase plate is provided by a frame extending around the periphery thereof

12. An apparatus according to claim 9, 10 or 11, wherein the recesses in the or each bar is a blind bore.

13. An apparatus according to any of claims 9 to 12, wherein each recess of the chase plate is a slot having at one end an indent for receiving the corresponding lug of the tool therein, when the or each clampingirelease bar is in its release position, to retain the or each bar in that position whilst one cutting die is replaced with another on the chase plate.

14. An apparatus according to any preceding claim, wherein retaining means are provided.

15. An apparatus according to any preceding claim, wherein the retaining means is provided on the side of the chase plate opposite that with which the - 11 clamping/release means is associated.

16. An apparatus according to claim 14 or 15, wherein the retaining means comprise a plurality of clips which are movable between respective operative and inoperative positions, for retaining an adjacent side of the base plate of a aitting die on the chase plate and for allowing that adjacent base plate side to be removed from the chase plate when the other side of the die base plate is released by the clampingirelease means.

17. An apparatus according to claim 16, wherein the retaining means is manually movable between its operative and inoperative positions.

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18. An apparatus according to claim 16 or 17, wherein the retaining means movable between its operative and inoperative positions by a lever or other suitable means.

c 1 c 1 1

19. An apparatus according to any of claims 14 to 18, wherein the retaining means is mounted upon a or the raised edge of the chase plate.

20. An apparatus according to claim 19, wherein the raised edge is provided by a or the peripheral fi-ame.

2 1. An apparatus according to any preceding claftn, wherein the chase plate is made of a ferrous material, such as steel.

22. An apparatus according to any preceding claim, wherein the main area of the base plate of the cutting die may be secured detachably to the generally central area of the chase plate by magnetic means.

- ti

23. An apparatus according to claim 22, wherein the magnetic means comprises a Z> plurality of magnetic elements arranged in an array and mounted to the cutting die base plate

24. An apparatus according to claim 23, wherein the magnetic elements are embedded in the cutting die base plate.

25. A magnetic element assembly for use in die cutting apparatus, comprising a body wifich is shaped and dimensioned to fit within a correspondingly- shaped and dimensioned aperture in the base plate of a cutting die and which includes a magnet and means arranged to permit the body to be fitted removably within the cutting die base plate aperture.

26. An assembly according to claim 25, wherein the body comprises a metallic material.

27. An assembly according to claim 25 or 26, wherein the means comprises at least one member mounted in and biased outwardly of the body for engaging a correspondingly-shaped recess, such as an annular groove, in the wall of the aperture of the cutting die base plate.

28. An assembly according to claim 25, 26 or 27, including a sleeve received in the cutting die base plate aperture.

29. An assembly according to claim 28, wherein the means comprises at least one member mounted in and biased outwardly of the body for engaging a correspondingly-shaped recess in an inner wall of the sleeve.

30. An assembly according to any of claims 25 to 29, wherein the body is circular M - in section vAth a central bore at one end of which the magnet, such as a disc magnet, is located.

1. An assembly according to claim 3 0, wherein the central bore is provided with an enlarged diameter portion defining therein an annular shoulder arranged to receive an end of a tool for removing the body, and hence the magnet, fl-om a correspondingly-shaped aperture in the cutting die base plate in which the magnetic element assembly is fixed during use.

32. An assembly according to any of claims 27 to 3 1, wherein the body is a push- fit within the aperture, such that the or each outwardly biased member is engaged within the correspondingly-shaped recess, to retain the magnetic element assembly withm the aperture during use but enabling the body to be removed from the aperture.

L 11 1 -1 i C

33. An assembly according to claim 32, wherein the body can be removed from the aperture using a removal tool.

34. An assembly according to claim 33, wherein an end of the tool for removing the body from the cutting die base plate aperture is provided with a foot for engaging the central body bore, to fiLeifitate removal of the body from the cutting die base plate aperture.

35. An assembly according to claim 34, wherein the tool engages a shoulder of the bore.

36. A die cutting apparatus substantially as described herein and with reference to the accompanying drawings.

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37. A magnetic element assembly substantially as described herein and with reference to the accompanying drawings.

38. A die cutting apparatus substantially as described herein incorporating a magnetic element assembly substantially as described herein and with reference to the accompanying drawings.