GB2475715A

GB2475715A - Drums with interchangeable components

Info

Publication number: GB2475715A
Application number: GB0920780A
Authority: GB
Inventors: Graham Michael Harris
Original assignee: Tech ni Fold Ltd
Current assignee: Tech ni Fold Ltd
Priority date: 2009-11-27
Filing date: 2009-11-27
Publication date: 2011-06-01
Anticipated expiration: 2029-11-27
Also published as: GB2475715B; GB0920780D0

Abstract

Apparatus features a first drum 6 with a circumferentially open channel (8,fig.2c), in which is currently mounted, a creasing ring 14. The channel (8,fig.2) may be of variable width so as to accommodate either the creasing ring, or a relatively wider anvil (44,fig.2a), or may alternately be used empty as a female channel on a second drum, to receive the creasing ridge of the creasing ring 14. The creasing ring 14 and anvil 44 may have lateral projections (52,fig.2a, 22, fig.2b) which can engage with complementary formations the female channel. The kit may also feature a cutting ring such as a perforating cutting ring (fig.3). Paper is passed between the first and second drums, which may fold the paper in different manners depending upon how the interchangeable parts are currently configured on the drums.

Description

TITLE

Creasing and cutting tools

DESCRIPTION

Technical field

The invention relates to apparatus for creasing or cutting paper as it is fed between two closely spaced drums mounted on counter-rotating shafts. The paper may be creased by passing between a circumferential creasing rib on one drum and a circumferential channel on the other drum. Additionally or alternatively, the paper io may be cut by passing it between a circumferential blade mounted on one shaft and a circumferential anvil on a drum mounted on the other shaft. The line of the crease or the cut is parallel to the direction of movement of the paper through the apparatus and perpendicular to the axes of the drums. Multiple tools may be mounted on a single pair of shafts to create multiple parallel cuts andlor creases in a single sheet of paper.

The invention has particular application to a kit of parts that can be configured in various ways to create different distributions of cuts andlor creases. The apparatus may form part of a stand-alone print finishing machine or be mounted as an accessory at the outlet of a printing machine.

The blade that acts against the anvil may be a continuous blade to part ("kiss-cut") the paper along a continuous line or it may be a perforating blade to perforate the paper along an intermittent line. In this specification, the word "cut" is used to refer to either operation unless the context indicates otherwise. The word "paper" is used generically to refer to paper, thin card or any other foil-like stock that is suitable for creasing and cutting.

Background of the invention

Print finishing tools are known that allow various arrangements of creasing rings and cutting blades in order to effect different patterns of creases, perforations and cuts on the paper that is being processed. Such tools comprise one or more of each of the following parts: a male drum, in which a creasing ring can be mounted; a female drum, which carries a receiving groove for the creasing ring; a blade for perforating or kiss-cutting the paper; and an anvil against which the blade can act. Multiple drums can be mounted on each shaft t provide different spacings and combinations of cuts, perforations and creases in the paper. Different tools can be mixed on the same shaft, for example male and female drums to combine forward and reverse creases of the paper. However, there are always discrete types of tools co-operating in pairs on the respective shafts: male and female creasing drums, or blades acting against anvils.

Known anvils comprise a rigid cylinder of a material such as nylon, which is soft compared with the cutting blade so that the blade can fully penetrate the paper without damage against the anvil, but is resistant enough that it does not become too quickly worn. However, with prolonged use, the anvil does eventually become worn and needs to be replaced long before the cutting blade. Replacement of the anvil cannot be effected without dismounting its shaft from the cutting and creasing apparatus, which prevents it from operating, and -if the apparatus is installed at the outlet of a printing machine -thereby prevents the whole machine from operating.

The aforementioned tools may be combined with an alternative type of blade which, rather than kiss-cutting or perforating the paper against an anvil, co-operates with the edge of a radial surface on the opposing shaft to slit the paper in a scissor or guillotine action. Traction bands may also be provided, either on outer surfaces of the aforementioned tools or on dedicated components, in order to grip the paper and prevent slippage as it moves through the apparatus.

Summary of the invention

The invention provides a kit of parts for an apparatus for creasing and cutting paper, as defined in claim 1.

Preferred but non-essential features of the invention are defined in the dependent claims.

By providing a single drum that can be adjusted to accommodate either a resilient creasing ring or an anvil ring, the invention allows the kit of parts to contain fewer components or to be used more flexibly. In some cases it may also allow the arrangement of creasing and cutting tools on a pair shafts to be reconfigured without the need to remove them from the shafts, thereby minimizing the down time of the apparatus. The dual use of the drum also reduces the inventory size and the manufacturing costs of the supplier of the kit of parts, thereby increasing efficiency.

The drawings Figure 1 is a view, partially in section, of one possible arrangement of a kit of parts in accordance with the invention on a pair of parallel shafts.

Figure 2 is an enlarged sectional view of the channel portion of a drum according to the invention: (a) when used to mount an anvil ring; (b) when used to mount a creasing ring; and (c) when used as a receiving groove.

Figure 3 is a schematic perspective view of a perforating blade for use with the invention.

In Figure 1, a first shaft 1 is mounted for rotation about a first axis 3 and a second shaft 2 is mounted for rotation in the opposite direction about a second axis 4, which is parallel to the first axis 3. In accordance with the invention there is provided a kit of parts including print finishing tools, which can be mounted in various configurations on the first and second shafts I,2 so that tools on the respective shafts co-operate to crease or cut a sheet of paper that passes between them as the tools counter-rotate. In Figure 1, the parts mounted on the first shaft 1 are shown in axial section in the area above the first axis 3; and the parts mounted on the second shaft 2 are shown in axial section in the area below the second axis 4.

One of the tools mounted on the first shaft I is a male creasing drum 6. The male creasing drum 6 has the general form of a cylinder that fits closely about the shaft 1 and is clamped to it to prevent rotation. As shown in more detail in Figure 2b, a circumferential channel 8 is formed in the outer surface 9 of the drum 6 between a step 10 and a collar 12 that may be screwed onto the drum via mutually co-operating threads or may be slid axially onto the drum and held in place by a grub screw (not shown). Mounted in the channel 8 is a creasing ring 14 made of rubber or a similar resilient material. The creasing ring 14 has a body 16 of generally rectangular cross section from which a creasing rib 20 projects radially around the whole circumference. The body 16 of the creasing ring 14 protrudes slightly above the surface 9 of the drum to form a pair of shoulders 18 on opposite sides of the creasing rib 20. The side walls of the channel 8 are undercut to form recesses. Retaining ribs 22 project axially from the body 16 of the creasing ring 14 to locate in those recesses, thereby preventing the ring 14 from being lifted out of the channel 8 in the radial io direction.

When the ring 14 needs to be removed from the channel 8, the collar 12 can be retracted to widen the channel 8 so that the retaining ribs 22 of the creasing ring 14 are no longer held in the recesses. The ring 14 is split at a location 24 around its circumference to form two mutually abutting ends, which can be separated to unwrap the ring 14 from the widened channel 8. A replacement ring can then be inserted by reversing the process, without any need to dismount the drum 6 from the shaft 1 or to dismount the shaft 1 from the machinery (not shown) in which it is mounted.

One of the tools mounted on the second shaft 2 is a female creasing drum 26. The female creasing drum 26 has the general form of a cylinder that fits closely about the shaft 2 and is clamped to it to prevent rotation. In the outer cylindrical surface 28 of the female drum is a set of receiving grooves 30 of varying width. Although not shown in Figure 1, the grooves 30 may also be of varying depth. The distance between the first and second axes 3,4 is arranged such that the outer surfaces 9,28 of the male and female drums 6,26 are close to one another. The male and female drums 6,26 are positioned along their respective shafts 1,2 such that they are mutually aligned and the creasing rib 20 of the creasing ring 14 mounted in the channel 8 of the male drum 6 projects towards, or into the mouth of, one of the receiving grooves 30 in the female drum 26. When the drums 6,26 are counter-rotated, a sheet of paper fed between the male creasing rib 20 and the female receiving groove 30 will be creased along its direction of travel. An appropriate one of the receiving grooves 30 may be selected according to the weight of paper being creased. Similarly, the kit of parts will generally include several creasing rings 14 with creasing ribs 20 of different widths. The rings 14 and receiving grooves 30 may be colour coded or marked in other ways to indicate suitable combinations.

A further tool mounted on the first shaft 1 is a perforating blade ring 32. The perforating blade ring 32 comprises a thin disc with a central hole for the shaft I. The rim of the disc is preferably double-bevelled to form a sharp outer edge 34. As shown schematically in Figure 3, the outer edge 34 is not continuous but is divided into a large number of discrete teeth 35, each of which is capable of penetrating a sheet of paper that passes through the print finishing apparatus, so that a line of perforations is formed in the paper. The teeth are typically evenly spaced at a density in the range of about 17 to 72 teeth per inch (approximately 7 to 28 teeth per centimetre) but in practice any number and arrangement of teeth may be provided around the edge of the perforating ring 32 in accordance with the desired pattern of perforations in the paper.

The perforating blade ring 32 is formed from a rigid and durable material such as a high grade steel so that it may be operated for a long period before becoming worn and needing to be replaced.

A further tool mounted on the second shaft 2 is an anvil drum 36. The anvil drum 36 has the general form of a cylinder that fits closely about the shaft 2 and is clamped to it to prevent rotation. A circumferential channel 38 is formed in the outer surface 39 of the anvil drum 36 between a step 40 and a collar 42 that may be screwed onto the drum via mutually co-operating threads 43 or may be slid onto the drum and held in place by a grub screw (not shown). As shown in more detail in Figure 2a, mounted in the channel 38 is an anvil ring 44, which has a body 46 of generally rectangular cross section that protrudes slightly above the surface 39 of the drum to form an anvil surface 48. The side walls of the channel 38 are undercut to form recesses. Retaining ribs 52 project axially from the body 46 of the anvil ring 44 to locate in those recesses, thereby preventing the ring 44 from being lifted out of the channel 38 in the radial direction.

The perforating blade 32 and the anvil drum 36 are positioned along their respective shafts 1,2 such that the blade 32 and the channel 38 of the anvil drum are mutually aligned. The distance between the first and second axes 3,4 is arranged such that the teeth 35 of the perforating blade 32 just penetrate the surface 48 of an opposing anvil ring 44 that is mounted in the anvil drum 36. When the two shafts 1,2 are then counter-rotated, a sheet of paper fed between the perforating blade 32 and the anvil drum 36 will be penetrated by the teeth 35 of the blade 32 to form a line of perforations in the paper along its direction of travel.

To allow for the slight penetration of the surface 48 of the anvil ring 44 by the teeth of the perforating blade 32, the anvil ring 44 is made of a material, such as nylon, that is relatively soft compared with the teeth 35. The material should not be so soft that it wears too rapidly but inevitably the anvil ring 44 will wear faster than the perforating blade 32. For this reason, the anvil ring 44 has a relatively large axial width -for example, 15mm -so that when the anvil surface 48 becomes worn at one axial position, a small adjustment can be made to the position of the anvil drum 36 along the second shaft 2 in order to bring an unworn region of the surface 48 into contact with the blade 32.

Eventually the anvil ring 44 will become ftilly worn and need to be replaced. Its removal from the channel 38 can be enabled by retracting the collar 42 to widen the channel 38 so that the retaining ribs 52 of the anvil ring 44 are no longer held in the sidewall recesses. The anvil ring 44 is split at a location 54 around its circumference to form two mutually abutting ends. The nylon or other material of the anvil ring 44 is typically quite stiff but is sufficiently resilient that its two abutting ends can be urged apart to a spacing greater than the diameter of the shaft 2 (i.e. greater than the internal diameter of the ring 44 in its resting state) and can still spring back together again without permanent deformation of the ring 44. Thus a gap can be opened up between the ends of the ring 44 that allows it to be removed from the shaft 2. A similar ring 44 can replace it by operating the procedure in reverse, without any need to dismount the anvil drum 36 from the shaft 2 or to dismount the shaft 2 from the machinery (not shown) in which it is mounted.

Although not shown in the drawings, the kit of parts may also comprise a cutting blade ring, which is very similar to the perforating blade ring 32, except that the sharp outer edge 34 of the cutting ring is a continuous blade, rather than being divided into teeth. When the two shafts 1,2 are counter-rotated, a sheet of paper fed between such a cutting blade and the anvil drum 36 will be "kiss-cut" by the cutting blade to form a continuous slit in the paper along its direction of travel. The cutting blade may fully penetrate the paper to divide it into two or, with precise control of the spacing between the axes 3,4 of the shafts, the blade may only partially penetrate the paper, for example to cut through a layer of labels but not through a backing sheet adhered to them.

Further components of the kit of parts are shown in the drawings. They include traction rings 60, which are cylinders having an outer diameter approximately equal to that of the male creasing drum 6 or the anvil drum 36. On the outer surface of each traction ring 60 is mounted a traction band 62, which is a slightly raised layer of rubber or another high-friction material that will grip the paper as it passes between the counter-rotating shafts 1,2 and prevent the paper from slipping. Instead of, or in addition to, dedicated traction rings 60, similar traction bands may be mounted on outer surfaces of the creasing drums 6,26, the anvil drum 36 or other tools mounted on the shafts 1,2.

The kit of parts also includes end clamps 70, which are solid rings, typically of metal, provided with means for firmly but releasably fixing the clamps 70 to the respective shafts 1,2. For example, the clamps 70 may be fixed by grub screws (not visible in the drawings) operated by Allen® keys via bores 72. The end clamps are used to hold the other tools in place by compressing the tools between a pair of clamps 70 on the respective shaft so that friction between adjacent tools prevents them rotating and the fixed clamps 70 prevent them moving axially. The end clamps 70 can only operate correctly if the length of shaft between them is completely filled so spacers 74 are provided to occupy any gaps between working tools. The spacers 74 must be made of a generally incompressible material but are not subject to significant wear so plastics are suitable. As shown, they may have a smaller diameter than the working tools so as not to interfere with the creasing and cutting operations. The spacers 74 may be provided in various widths so that suitable combinations of them can be used to achieve the desired distances between the working tools.

In Figure 1, the tools 6,32,60,74 mounted on the first shaft 1 are shown as being held by clamps 70 as just described, while the tools 26,3 6 mounted on the second shaft 2 are individually fixed to it by means such grub screws not visible in the drawing.

Other arrangements are possible and most types of tool may have an inbuilt fixing means or be held between end clamps 70 as desired. However, the perforating blades 32 and cutting blades, if manufactured as thin steel discs as described, will generally be unable to accommodate inbuilt fixing means so will have to be held between end clamps 70.

It will be appreciated that, in accordance with the present invention, the method of mounting the anvil ring 44 in the anvil drum 36 is similar to the method of mounting the creasing ring 14 in the male creasing drum 6. In each case, a channel 8,38 is formed in the drum 6,36 between a step 10,40 and an axially movable collar 12,42.

Recesses in the sidewalls of the channel 8,38 engage axially projecting, circumferentially extending ribs 22,52 on the creasing ring 14 or anvil ring 44. In the light of this similarity, the anvil drum 36 and the male creasing drum 6 may in fact be identical components. As the anvil ring 44 is typically wider than the creasing ring 14, the channel 8,38 formed in the drum 6,36 must have a different width according to the use to which it is to be put. That can easily be accommodated by moving the collar 12,42 to different axial positions relative to the drum 6,36, as seen in Figure 1.

Figure 1 shows a wide collar 12 used with the creasing drum 6 to complement the narrow creasing ring 14; and a narrow collar 42 used with the anvil drum 36 to complement the wide anvil ring 44. But it is equally possible to use the same, narrow collar with the narrow creasing ring 14, as seen in Figure 2b, thereby reducing further o the number of different types of component required. -.9-

A further possibility for reducing the number of different types of components, or for increasing the flexibility of use of a given kit of components, is to use a male creasing drum 6 or an anvil drum 36 (which, as just described, may be the same component) in place of a distinct female creasing drum 26. The width of the channel 8,38 in the male/anvil drum 6,36 can be varied by moving the collar 12,52 axially so that the width of the channel 8,38 becomes suitable for acting as a receiving groove for the creasing rib of an opposing creasing ring 14, as shown in Figure 2c. In other words, instead of a female drum 26 with a fixed set of receiving grooves 30 of different widths as shown in Figure 1, the channel 8,38 of the male/anvil drum 6,36 can be used as a single receiving groove of variable width.

Claims

CLAIMS1. A kit of parts for an apparatus for creasing and cutting paper comprising: a first drum having a circumferential, outwardly opening first channel; a resilient creasing ring that can be mounted in the first channel such that a creasing rib of the creasing ring projects from the first channel; and an anvil ring that can be mounted in the first channel in place of the creasing ring.
2. A kit of parts according to claim 1, wherein the width of the first channel isadjustable.
3. A kit of parts according to claim 2, wherein the width of the anvil ring is different from the width of the creasing ring.
4. A kit of parts according to any preceding claim, wherein the anvil ring has a generally cylindrical, outwardly facing anvil surface.
5. A kit of parts according to claim 4, wherein the first drum has a generally cylindrical outer surface, and wherein the radius of the anvil surface of the anvil ring is slightly greater than the radius of the outer surface of the first drum.
6. A kit of parts according to any preceding claim, wherein: the first drum comprises a recess in a side wall of the first channel; the creasing ring comprises a lateral projection that complements the recess in the side wall of the first channel to prevent removal of the creasing ring in the radial direction when the creasing ring is mounted in the first channel; and the anvil ring comprises a lateral projection that complements the recess in the side wall of the first channel to prevent removal of the anvil ring in the radial direction when the anvil ring is mounted in the first channel.
7. A kit of parts according to claim 6, wherein the anvil ring is split at at least one location around its circumference to form two mutually abutting ends. -Il-
8. A kit of parts according to claim 7. wherein the anvil ring is split at just one location around its circumference and is sufficiently flexible that the two ends of the anvil ring may be moved apart by at least a predetermined distance without permanent deformation, the predetermined distance being equal to the inner diameter of the anvil ring when it is mounted in the first channel.
9. A kit of parts according to any preceding claim, further comprising a second drum having a circumferential, outwardly opening second channel, wherein the second channel is suitable for receiving the creasing rib of the creasing ring when mounted on the first drum, such that a sheet of paper can be creased between the creasing rib and the second channel.
10. A kit of parts according to claim 9, wherein the first and second drums are of the same design so as to be interchangeable.
11. A kit of parts according to any preceding claim, further comprising a circular blade that is suitable for acting against the anvil ring when the anvil ring is mounted on the first drum, such that a sheet of paper can be cut between the blade and the anvil ring.
12. A kit of parts according to claim 11, wherein the circular blade is a perforating blade.
13. A kit of parts for an apparatus for creasing and cutting paper comprising a first drum, a resilient creasing ring and an anvil ring substantially as described herein with reference to the drawings.