BACKGROUND OF THE INVENTION

Field of the Invention

[0001] The present invention relates to a cover for a rotary die cutting anvil cylinder and, more particularly, a locking arrangement for an anvil cover.

Description of Related Art

[0002] Rotary die cutting is a process, wherein either a continuous web or single sheets of material, e.g., corrugated paper or cardboard, is traversed by way of roller sets or rollers within a differential pressure plenum through the die-cutting machine. Ultimately, this material is passed through a set of rollers, which consists of the die cylinder and the anvil cylinder. A cutting die, which is made up of cutting knives and a scoring rule, is mounted on the die cylinder. The anvil cylinder is covered with a removable resilient material, typically referred to as an anvil cover or blanket. The cylinders rotate about parallel axes. As material being processed passes between this set of cylinders, the cutting die penetrates through the material and into the anvil, producing the intended product.

[0003] Anvil covers are flexible and wrap around the rotating anvil cylinder. They are typically constructed of a thin sheet metal liner, however, wire, plastic, or nylon mesh is also utilized. Locking members are attached to one or both ends of the liner, and an elastically resilient material, such as urethane, is molded to the outer surface of the assembly. The blankets are built in a variety of sizes, circumferences, lengths, and thicknesses, which complies with the machinery manufacturers' specifications for anvil cylinder construction. Typically, a plurality of covers is used to cover the length of a standard anvil cylinder. The anvil cylinder is typically constructed of steel or cast iron. However, the anvil cylinder arrangement may also be formed from a basic cylinder surrounded by a series of one-piece or multi-piece slip bearings. The anvil cylinder or slip bearing arrangement is commonly supplied with a channel running parallel to the axis of rotation. This channel is used to attach and mount the anvil cover to the cylinder.

[0004] One particular anvil cylinder design is generally shown in U.S. Patent No. 6,845,700 to Capdeboscq and commercially available as the Bobst Martin Rotary Die Cutter Quick Lock Anvil (QLA). The QLA system includes an anvil cylinder defining a channel having first and second jaws that are configured to move relative to each other to secure ends of the anvil cover within the channel. During installation of the anvil cover, the jaws are in an open position that allows the insertion of both ends of the cover. The ends of the cover are then compressed together by closing the jaws within the channel by mechanically moving the jaws closer together.

SUMMARY OF THE INVENTION

[0005] In accordance with an aspect of the present invention, a cover for a rotary die cutter anvil cylinder includes a cover body having a first end and a second end positioned opposite the first end with the cover body configured to be positioned about a rotary die cutter anvil. The cover also includes a first set of members positioned at the first end of the body with each of the members of the first set of members defining a first recess configured to engage a first movable jaw of an anvil cylinder, and a second set of members positioned at the second end of the body with each of the members of the second set of members defining a first recess configured to engage a second moveable jaw of an anvil cylinder. The first set of members is configured to interlock with the second set of members.

[0006] A member of the first set of members and a member of the second set of members may each define a second recess positioned opposite from the first recess with the second recess of the first set of members configured to be aligned with a corresponding first recess of the second set of members when the first set of members is interlocked with the second set of members. The second recess of the second set of members is configured to be aligned with a corresponding first recess of the first set of members when the first set of members is interlocked with the second set of members.

[0007] The cover may have an open position where the first set of members are spaced from the second set of members and a closed position where the first set of members is interlocked with the second set of members, and where the cover is configured to be positioned over an anvil cylinder when in the open position. The cover may also be configured to be moveable along an anvil cylinder when in the closed position.

[0008] The first end of the cover body may define a first set of openings and the second end of the cover body may define a second set of openings, with the second set of openings configured to receive respective members of the first set of members and the first set of openings configured to receive the second set of members. The first set of members and the second set of members may be dovetail shaped.

[0009] Each member of the first and second sets of members may have a member body projecting from the cover body, with the member body configured to be received within a channel of an anvil cylinder. Each of the member bodies may extend radially inward when the cover is positioned about an anvil cylinder.

[0010] At least one of the first and second ends of the cover body may include a magnet. The magnet may be positioned on at least one of the members of the first or second sets of members. The magnet may be embedded within one of the members of the first or second sets of members.

[0011] A middle member of the first set of members may extend a shorter distance from the first end of the cover body than other members of the first set of members, with one of the openings of the second set of openings sized to receive the middle member. The middle member of the first set of members may be positioned at about a middle of the first end of the cover body.

[0012] The cover body may be cylindrical when the first and second ends of the cover body are in the closed position. At least one of the members of the first set of members may be positioned at an edge of the cover body. One of the members of the first set of members may be positioned at a first edge of the cover body and another one of the members of the first set of members may be positioned at a second edge opposite from the first edge. The first set of members and the first set of openings may alternate along the first end of the cover body.

[0013] In a further aspect, a method of rotating a plurality of covers positioned on a rotary die cutter anvil cylinder having a channel with first and second movable jaws, with each of the plurality of covers having first and second sets of members, includes moving the first and second moveable jaws from a closed position in which the first and second moveable jaws of the anvil cylinder are engaged with first and second ends of the plurality of covers to an open position in which each of the plurality of covers is moveable relative to the first and second jaws of the anvil cylinder; removing a first cover of the plurality of covers from the anvil cylinder by removing the first set of members of the first cover from the second set of members of the first cover; moving a second cover of the plurality of covers along the anvil cylinder with the first and second sets of members of the second cover interlocked with each other; securing the first cover of the plurality of covers to the anvil cylinder by positioning the first and second sets of members within the channel of the anvil cylinder; and moving the first and second jaws of the anvil cylinder to the closed position.

[0014] The first cover of the plurality of covers may include a magnet positioned at one of the members of the first set of members, where the first cover of the plurality of covers is secured to the anvil cylinder by first positioning the first set of members within the channel of the anvil cylinder and where the magnet at least partially securing the first set of members within the channel of the anvil cylinder. The magnet may secure at least one member of the first set of members to a bottom of the channel of the anvil cylinder.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] FIG.

application.

[0016] FIG.

[0017] FIG.

[0018] FIG.

[0019] FIG.

[0020] FIG.

[0021] FIG.

[0022] FIG.

[0023] FIG.

die cutter anvil cylinder according to one aspect of the present application, showing the anvil covers in an open position and a closed position, respectively.

[0024] FIG. 8 is a right side view of the anvil covers shown in FIG. 7.

[0025] FIG. 9 is a top view of the anvil covers shown in FIG. 7.

[0026] FIG. 10 is a front view of the anvil covers shown in FIG. 7.

[0027] FIG. 10A is an enlarged view of area 10A shown in FIG. 10.

[0028] FIG. 11 is a cross-sectional view taken along line 11-11 in FIG. 9.

[0029] FIG. 11 A is an enlarged view of area 11 A shown in FIG. 11.

[0030] FIG. 12 is a cross-sectional view taken along line 12-12 in FIG. 9, showing jaws of the anvil cylinder in an open position.

[0031] FIG. 12A is an enlarged view of area 12A shown in FIG. 12.

[0032] FIG. 13 is a cross-sectional view taken along line 12-12 in FIG. 9, showing jaws of the anvil cylinder in a closed position.

[0033] FIG. 13A is an enlarged view of area 13A shown in FIG. 13.

[0034] FIG. 14 is a schematic view showing an anvil cover rotation method according to one aspect of the present application.

[0035] FIG. 15 is a schematic view showing a rotated position of the anvil covers of FIG. 13.

DESCRIPTION OF THE INVENTION [0036] For purposes of the description hereinafter, the words "upper", "lower", "right", "left", "vertical", "horizontal", "top", "bottom", "lateral", "longitudinal", and like spatial terms, if used, shall relate to the described aspects as oriented in the drawing figures. However, it is to be understood that many alternative variations and aspects may be assumed except where expressly specified to the contrary. It is also to be understood that the specific devices and aspects illustrated in the accompanying drawings and described herein are simply exemplary aspects of the invention.

[0037] Referring to FIGS. 1-13A, a cover 10 for a rotary die cutter anvil cylinder according to one aspect of the present invention is shown. The cover 10 is configured to be positioned about and secured to a rotary die cutter anvil cylinder 12. The anvil cylinder 12 includes a channel 14 having first and second moveable jaws 16, 18. In one aspect, the cover 10 is compatible with the Bobst Martin Rotary Die Cutter QLA system, although the cover 10 may also be utilized with other suitable anvil cylinder arrangements.

[0038] Referring to FIGS. 1-6A, the anvil cover 10 includes a cover body 20 having a first end 22 and a second end 24 positioned opposite the first end 22. The cover body 20 may be formed from an elastically resilient material, such as urethane, although other suitable material and arrangements may be utilized. The cover body 20 is flexible and can be laid flat and will generally be cylindrical when positioned about the anvil cylinder 12. The cover body 20 includes a top surface 26, a bottom surface 28 positioned opposite the top surface 26, a first edge 30, and a second edge 32 positioned opposite the first edge 30. The cover 10 includes a first set of members 36 positioned at the first end 22 of the cover body 20 and a second set of members 38 positioned at the second end 24 of the cover body 20. The first and second sets of members 36, 38 are configured to interlock with each other such that the first end 22 of the cover body 20 is secured to the second end 24 of the cover body 20. The first and second sets of members 36, 38 form a dovetail connection with each other, although other suitable locking arrangements may be utilized.

[0039] In particular, the first end 22 of the cover body 20 defines a first set of openings 40 and the second end 24 of the cover body 20 defines a second set of openings 42. The second set of openings 42 are configured to receive respective members of the first set of members 36 and the first set of openings 40 are configured to receive respective members of the second set of members 38. Due to the shape of the first and second sets of members 36, 38 and the first and second sets of openings 40, 42, when the first set of members 36 is positioned within the second set of openings 42 and the second set of members 38 is positioned within the first set of openings 40, the first end 22 of the cover body 20 will be secured to the second end 24 of the cover body 20. The first set of members 36 may be removed from the second set of members 38 by applying an upward force to the first end 22 of the cover body 20 while restraining the second end 24 of the cover body 20, or vice versa. A tool (not shown) may be used to separate the first and second sets of members 36, 38.

[0040] Referring to FIGS. 5-6A, each of the members of the first set of members 36 includes a member body 46 extending from the bottom surface 28 of the cover body 20. Each of the member bodies 46 of the first set of members 36 extends radially inward when the cover 10 is positioned about the anvil cylinder 12 and is configured to be received within the channel 14 of the anvil cylinder 12, which is discussed in more detail below. In a similar manner, each of the members of the second set of members 38 includes a member body 48 extending from the bottom surface 28 of the cover body 20. Each of the member bodies 48 of the second set of members 38 extends radially inward when the cover 10 is positioned about the anvil cylinder 12 and is configured to be received within the channel 14 of the anvil cylinder 12. Each of the members of the first set of members 36 defines a first recess 52 configured to engage the first movable jaw 16 of the anvil cylinder 12 and each of the members of the second set of members 38 defines a first recess 54 configured to engage the second moveable jaw 18 of the anvil cylinder 12. Further, except for a middle member 56 and edge members 58 of the first set of members 36, each of the members of the first set of members 36 define a second recess 60 positioned opposite from the first recess 52. Except for the middle member 56 and the edge members 58, each of the members of the first set of members 36 project from the first end 22 of the cover body 20 beyond the member bodies 46. Each of the members of the second set of members 38 also define a second recess 62 positioned opposite from the first recess 54. Each of the members of the second set of members 38 project from the second end 24 of the cover body 20 beyond the member bodies 48. The second recesses 60 of the first set of members 36 are configured to be aligned with a corresponding first recess 54 of the second set of members 38 when the first set of members 36 is interlocked with the second set of members 38 to form a continuous channel for receiving the second moveable jaw 18 of the anvil cylinder 12. The second recesses 62 of the second set of members 38 are configured to be aligned with a corresponding first recess 52 of the first set of members 36 when the first set of members 36 is interlocked with the second set of members 38 for receiving the first moveable jaw 16 of the anvil cylinder 12.

[0041] Referring to FIGS. 1 and 4, the first set of members 36 of the cover 10 includes the middle member 56 positioned at about the middle of the first end 22 of the cover body 20 between the first and second edges 30, 32 of the cover body 20. The first set of members 36 also includes the edge members 58 positioned at the first and second edges 30, 32 of the cover body 20, respectively. The middle member 56 and edge members 58 extend a shorter distance from the first end 22 of the cover body 20 than other members of the first set of members 36, although the middle member 56 is wider and the edge members 58 are narrower than the other members of the first set of members 36. Further, corresponding openings of the second set of openings 42 are sized and shaped to receive the middle member 56 and the edge members 58.

[0042] Referring to FIGS. 6 and 6 A, one of the members of the first set of members 36 includes a magnet 70. In particular, the magnet 70 is embedded within the member body 46 of one of the members of the first set of members 36 and is configured to secure the first end 22 of the cover body 20 within the channel 14 of the anvil cylinder 12 as discussed in more detail below. The magnet 70 may be a permanent magnet, such as neodymium iron boron, samarium cobalt, alnico, ceramic, or ferrite magnets, although other suitable magnets and arrangements may be utilized. Although the magnet 70 is only shown on one of the members of the first set of members 36, the magnet 70 may be provided on one or more of the members of the first set of members 36 and one or more of the members of the second set of members 38. In a further aspect of the anvil cover 10, neither the first set of members 36 nor the second set of members 38 includes the magnet 70.

[0043] Referring to FIGS. 7- 13 A, a pair of anvil covers 10 are shown positioned about the anvil cylinder 12. In typical arrangements, a plurality of anvil covers 10 are positioned about the anvil cylinder 12 along the length of the anvil cylinder 12, although one or more covers 10 may be provided. As shown, the anvil cover 10 has an open position where the first set of members 36 are spaced from the second set of members 38 and a closed position where the first set of members 36 is interlocked with the second set of members 38. When the anvil cover 10 is in the open position, the cover 10 is configured to be positioned over the anvil cylinder 12 by feeding the first end 22 of the cover body 20 around the anvil cylinder 12 and positioning the first end 22 of the cover body 20 adjacent to the second end 24 of the cover body 20.

[0044] Referring to FIG. 11, the second set of members 38 are positioned over the channel 14 of the anvil cylinder 12 with the member bodies 48 of the second set of members 38 positioned within the channel 14. The first and second moveable jaws 16, 18 of the anvil cylinder 12 have an open position to receive the member bodies 46, 48 and a closed position where the first and second moveable jaws 16, 18 are displaced relative to each other and are configured to be received within the respective first and second recesses 52, 54, 60, 62 of the first and second sets of members 36, 38. As noted above, the first set of members 36 and/or the second set of members 38 may include one or more magnets 70 to secure the member bodies 46, 48 within the channel 14 of the anvil cylinder 12. More specifically, the member bodies 48 of the second set of members 38 are positioned within the channel 14 of the anvil cylinder 12 with one or more magnets 70 securing the member bodies 48 within the channel 14 while the first set of members 36 are positioned and interlocked with the second set of members 38 as described above. The magnet(s) 70 may be secured to a bottom of the channel 14 of the anvil cylinder 12, although other suitable arrangements may be utilized. The member bodies 48 of the second set of members 38 may also be manually held in position within the channel 14 of the anvil cylinder 12 if the magnet(s) 70 are not provided.

[0045] Referring to FIGS. 12 and 12 A, one of the anvil covers 10 is shown in the closed position with the first and second moveable jaws 16, 18 of the anvil cylinder 12 in the open position. In this position, the first end 22 of the cover body 20 is secured to the second end 24 of the cover body 20 and the cover 10 is moveable along the length or longitudinal axis of the anvil cylinder 12. The position of the anvil cover 10 may be adjusted and moved to a desired location prior to moving the first and second moveable jaws 16, 18 to the closed position.

[0046] Referring to FIGS. 13 and 13 A, the anvil cover 10 is shown in the closed position as in FIG. 12, but with the first and second moveable jaws 16, 18 of the anvil cylinder 12 in the closed position. The first moveable jaw 16 is received within the first recesses 52 of the first set of members 36 and the second recesses 62 of the second set of members 38. The second moveable jaw 18 is received within the first recesses 54 of the second set of members 38 and the second recesses 60 of the first set of members 36. When the first and second jaws 16, 18 of the anvil cylinder 12 are moved to the closed position, the first and second jaws 16, 18 engage the member bodies 46, 48 of the first and second sets of members 36, 38 and force the first and second ends 22, 24 of the cover body 20 toward each other to substantially close the gap between the first and second ends 22, 24 of the cover body 20, particularly the gaps between the first and second sets of members 36, 38. Moving the jaws 16, 18 to the closed position also secures the anvil cover 10 to the anvil cylinder 12.

[0047] As discussed above, the first and second sets of members 36, 38 interlock with each other, which aligns the first edge 30 of the cover 10 with the second edge 32 of the cover 10 thereby eliminating the need to align the edges 30, 32 and the problem of misaligned edges after the jaws 16, 18 are moved to the closed position. Further, the interlocked ends 22, 24 of the cover 10 allows the anvil cover 10 to act as a continuous strip, which makes lateral adjustment easier by moving the jaws 16, 18 to the open position without having the ends 22, 24 disengage from the channel 14 of the anvil cylinder 12. Conventional cover locking arrangements for the QLA system typically utilize two separate members that are not interlocked with each other, which potentially allows for movement of the cover within the channel of the anvil cylinder. However, the first and second set of members 36, 38 of the cover 10 interlock to form a unitary piece that substantially fills the channel 14 of the anvil cylinder 12 thereby reducing movement of the cover 10 within the channel 14 during die cutter operation and improving die cutter performance. Accordingly, installation of the anvil cover 10 onto the anvil cylinder 12 is improved in both speed and accuracy and better performance of the anvil cover 10 is achieved due to the elimination of gaps between the ends 22, 24 of the cover 20 and the secure attachment within the channel 14 of the anvil cylinder 12.

[0048] The anvil covers 10 are typically rotated regularly to prevent uneven wear of the anvil covers 10 and to maintain die cutting performance. Shortening the time required for rotating the anvil covers 10 helps to minimize downtime of the die cutting process.

[0049] Referring to FIGS. 14 and 15, the anvil cover 10 allows for "slide-type" rotations due to the interlocking of the first and second sets of members 36, 38, which helps to minimize the time required for anvil cover rotation. The first and second moveable jaws 16, 18 may be moved to the open position to allow one of the covers 10 to be removed and the remaining covers to be slid or moved along the anvil cylinder 14 to a new position. Conventional arrangements require the ends 22, 24 of the cover 10 to be engaged with the jaws 16, 18 to remain attached to the cylinder 12 and cannot utilize the slide-type rotation.

[0050] In one aspect, a method of rotating a plurality of the anvil covers 10 positioned on the anvil cylinder 12 includes moving the first and second moveable jaws 16, 18 from the closed position in which the first and second moveable jaws 16, 18 of the anvil cylinder 12 are engaged with first and second ends 22, 24 of the plurality of covers 10 to the open position in which each of the plurality of covers 10 is moveable relative to the first and second jaws 16, 18 of the anvil cylinder 12 . A first cover of the plurality of covers 10 is removed from the anvil cylinder 12 by removing the first set of members 36 of the first cover from the second set of members 38 of the first cover. A second cover of the plurality of covers 10 is then moved along the anvil cylinder 12 with the first and second sets of members 36, 38 of the second cover interlocked with each other as shown in FIGS. 12 and 12A. The first cover of the plurality of covers 10 is secured to the anvil cylinder 12 by positioning the first and second sets of members 36, 38 within the channel 14 of the anvil cylinder 12. The first and second jaws 16, 18 of the anvil cylinder 12 are then moved to the closed position to secure the anvil covers 10 to anvil cylinder 12 and to close the gap between the ends 22, 24 of the anvil cover 10. As noted above, the magnet 70 may at least partially secure the first or second set of members 36, 38 within the channel 14 of the anvil cylinder 12 to initially secure the first or second ends 22, 24 of the cover body 20 within the channel 14 of the anvil cylinder 12.

[0051] While the present invention is described with reference to several distinct aspects of an anvil cover and method of use, those skilled in the art may make modifications and alterations without departing from the scope and spirit. Accordingly, the above detailed description is intended to be illustrative rather than restrictive.