Web Perforating Utilizing a Single Perf Cylinder and Dual Anvils

In conventional paper web perforating systems, and in conventional procedures for producing perforated business forms or the like from paper webs, when two sets of perforations are desired the web is passed over an anvil cylinder and perforating blades (or like perforating elements) on each of a pair of perforating cylinders which are rotated into contact with the web as it passes over the single anvil cylinder. When it is desired to adjust the spacing between the first and second sets of perforations formed by the perforating cylinders, it is necessary to adjust the position of one of the perforating cylinders with respect to the other perforating cylinder and the anvil cylinder. Such an adjustment is difficult and often imprecise. Utilizing such a conventional system and procedures, when the perforating blades must be periodically changed, two sets of blades (one associated with each set of perforating cylinders) must be replaced, resulting in a significant amount of down time at that particular point in time. Further, if it is desirable to use the system to form only a single set of perforations, one of the perforating cylinders must be moved out of operative association with the anvil cylinder.

According to the present invention an assembly and method are provided which overcome the drawbacks of the prior art system and procedures set forth above. In particular, according to the present invention a single perforating cylinder is utilized, and it is disposed in operative association with first and second anvil cylinders. All of the cylinders are rotatable about parallel, spaced axes, and the first and second anvil cylinders are mounted with respect to the perforating cylinder so that the web perforating elements (e.g. interrupted blades) extending outwardly from the perforating cylinder cooperate with the anvil cylinders so that a paper web passing between the perforating cylinder and one or both of the anvil cylinders is perforated thereby.

In the preferred embodiment of the assembly according to the invention, the spacing between the first and second sets of perforations formed in the web by cooperation between the perforating cylinder and the first and second anvil cylinders, respectively, is precisely controlled by adjusting the length of the web between the first, and second anvil cylinders. Preferably a compensator roller is provided over which the web passes, and the spacing of the compensator roller with respect to the perforating cylinder is adjusted by moving the axis of rotation of the compensator roller with respect to the perforating cylinder.

In addition to the compensator roller, various additional rollers are provided for directing the web in its path between the first and second anvil cylinders. Additionally, another roller, or other rollers, are provided so that the web may move in an alternate path in which after it passes between the first anvil cylinder and the perforating cylinder it bypasses the second anvil cylinder, so that only a single set of perforations is formed in the web. In all cases, the axes of the perforating cylinder and the first and second anvil cylinders remain stationary with respect to each other, and only the lighter, more easily controlled, compensator roller need be moved.

The invention also relates to a method of perforating a paper web in the production of business forms and the like utilizing a single perforating cylinder and first and second anvil cylinders, including precisely controlling the spacing of the sets of perforations formed in the web by cooperation between the perforating cylinder and the first anvil cylinder, on the one hand, and the perforating cylinder and the second anvil cylinder, on the other.

It is the primary object of the present invention to provide an apparatus and method for the simple, effective, and versatile perforation of a web, such as a paper web in the production of business forms. This and other objects of the invention will become clear from an inspection of the detailed description of the invention, and from the appended claims.

FIG. 1 is a schematic side view representation of a conventional prior art system for forming two spaced sets of perforations in a moving web;

FIG. 2 is a schematic side view representation of an exemplary web perforating assembly according to the present invention as utilized in the production of a web with two sets of spaced perforations; and

FIG. 3 is a view like FIG. 2 only showing the assembly when used to produce a web having a single set of perforations.

FIG. 1 shows a conventional prior art perforating assembly over which the invention is an improvement. The system illustrated in FIG. 1 is basically the same as that shown (in more detail) in prior U.S. Pat. No. 4,074,599, and comprises a single anvil cylinder 10 over which a web is directed by a pair of rollers 11, 12. First and second perforating cylinders 13, 14, respectively, cooperate with the anvil cylinder 10 to form two sets of perforations in the web, spaced along the length thereof. To adjust the spacing between the sets of perforations it is necessary to move the cylinder 14 with respect to the cylinders 10, 13. When it is necessary to change the perforating elements, all of the perforating elements 15 associated with the cylinder 13, and perforating elements 16 associated with the cylinder 14, are changed at the same time, resulting in significant down time at that point in time. When it is desirable to form only one set of perforations in the web, one of the cylinders 13, 14 must be moved out of operative association with the anvil cylinder 10.

An exemplary web perforating assembly according to the present invention is shown generally by reference numeral 20 in FIGS. 2 and 3. The assembly 20 includes a single perforating cylinder 21. The cylinder 21 is rotatable about a first axis 22 and has a periphery 23 with web-perforating elements 24 operatively extending therefrom. The exact nature of the web perforating elements 24 will depend upon the types of perforations being formed in the web. Preferably the elements 24 comprise a plurality of sets of interrupted blades extending in-line parallel to the axis 22 along the periphery 23, such as disclosed in U.S. Pat. No. 4,074,599. In the preferred embodiment illustrated, four sets of elements 24 are provided, although virtually any number of sets of elements 24 regularly spaced from each other along the periphery 23 at angle B.

The assembly 20 also includes a first anvil cylinder 31 rotatable about a second axis 32 and having a periphery 33. The axis 32 is parallel to and spaced from the axis 22. The assembly 20 further comprises a second anvil cylinder 41 rotatable about a third axis 42, and having a periphery 43. The axis 42 is parallel to, and spaced from, the axes 22, 32. The exact construction of the anvil cylinders 31, 41 will depend upon the nature of the perforating elements 24. For instance when the perforating elements 24 are interrupted blades, such as shown in U.S. Pat. No. 4,074,599, the cylinders 31, 41 will have smooth, hardened peripheries 33, 43. Note that in the drawings the lengths of the elements 24 are exaggerated for clarity of illustration.

Also part of the assembly 20 are the first and second rollers 51, 52. These rollers comprise means for directing the web in a first path, as illustrated in FIG. 2, operatively between the first anvil cylinder 31 and the perforating cylinder 21, and then operatively between the second anvil cylinder 41 and the perforating cylinder 21. The cylinders 31, 41 are mounted with respect to the cylinder 21 so that two sets of spaced perforations are formed in the web when it passes in the first path illustrated in FIG. 2.

In the preferred embodiment illustrated in FIG. 2, note that the lines 53 and 54 passing between the axes 22, 32 and 22, 42, respectively, have an angle B1 therebetween. The angle B1 is preferably equal to, or an even multiple of, the angle B. For instance for the preferred embodiment illustrated in the drawings, the angles B and B1 are both 90.degree. so that the first and second sets of perforations are formed in the web substantially simultaneously. Other configurations also may be provided depending upon the particular equipment utilized and results desired.

The assembly 20 also preferably comprises means for precisely controlling the predetermined desired spacing between the first and second sets of perforations formed along the web by controlling the length of the web between the cylinders 31, 41. Such web length control means preferably comprises a compensator roller 60 which is rotatable about a fourth axis 61 parallel to, and spaced from, the axes 22, 32, and 42. Means are provided, illustrated schematically by reference numeral 62 in FIG. 2, for moving the axis 61 of compensator roller 60 in a line toward and away from the axis 22, thereby adjusting the length of the web between the cylinders 31, 41. The structure 62 may comprise a pneumatic cylinder, or a wide variety of other conventional linear motion effecting means.

Note the position of the compensator roller 60 in FIG. 2 with respect to the first and second rollers 51, 52, and the axes of the cylinders 21, 31, 41. The compensator roller axis 61 is on the opposite side of a line 63 passing between the axes 32, 42 from the axis 21. Also the axis of rotation 64 (fifth axis of rotation) of the first roller 51 and the axis of rotation 65 (sixth axis of rotation) of the roller 52 are essentially in line with each other, and on the opposite sides of a line (not shown) passing between the axes 22, 61. The axes 64, 65 are also mounted on the opposite side of the line 63 from the axis 22.

When it is desired to utilize the assembly 20 to form only a single set of perforations in the web, instead of two sets of perforations (as when the web is passing in the first path illustrated in FIG. 2), the web is caused to pass in a second path, illustrated in FIG. 3. In the second path, the web bypasses the second anvil roller 41. In the second path, as the web passes from between the cylinders 21, 31 it passes into contact with the second roller 52 (instead of passing into contact with the first roller 51), and then passes into contact with another roller 68, which is on the same side of the line 63 as the roller 52.

As will be seen from an inspection of FIGS. 2 and 3, it is never necessary in normal operations to move the cylinders 21, 31, 41 with respect to each other. To adjust the spacing between the first and second sets of perforations it is necessary only to move the smaller, lighter, compensator roller 60. To use the same assembly 20 to form only a single set of perforations, it is necessary only to pass the web into operative association with the roller 68, rather than moving the cylinder 41. When it is necessary to change the elements 24 (on the single cylinder 21) need be changed at one time, resulting in less down time at that particular point in time.

While the invention has been specifically described with respect to two anvil cylinders cooperating with a single perforating cylinder, additional anvil cylinders could also be provided associated with the single perforating cylinder (e.g. four anvil cylinders disposed in pairs and for perforating two separate webs).

To form two sets of spaced perforations in a web, such as in the practice of a method of perforating a paper web in the production of business forms and the like, the web is caused to pass between a perforating cylinder 21 and a first anvil roller 31, around a compensator roller 60, and then between the perforating cylinder 21 and a second anvil roller 41. During rotation of the cylinders 21, 31, 41 about their axes, the perforating elements 24 operatively come into contact with the web at the areas thereof between the cylinders 21, 31, and 21, 41, respectively, to form two sets of perforations spaced from each other along the web. The exact spacing between the sets of perforations is controlled precisely and easily by adjusting the length of the web between the cylinders 31, 41, as by moving the axis 61 of compensator roller 60 with respect to the axis 22 of perforating cylinder 21. In the embodiment illustrated in FIG. 2, the two sets of perforations will be formed simultaneously since the angle B1 equals the angle B; however under some circumstances the angles B1 and B desirably would be made significantly different so that the perforations were not formed simultaneously.

When it is desired to use the assembly 20 to form only a single set of perforations in the web, the web is cut at a point between the rollers 51, and 60, and is rethreaded so that after passage between the cylinders 21, 31 it passes directly into engagement with the roller 52, and then into engagement with the roller 68, as illustrated in FIG. 3. In this second path of the web it bypasses the second anvil cylinder 41 so that only a single set of perforations is formed.

It will thus be seen that according to the present invention a simple and effective assembly and method have been provided for perforating a web. While the invention has been herein shown and described in what is presently conceived to be the most practical and preferred embodiment thereof, it will be apparent to those of ordinary skill in the art that many modifications may be made thereof within the scope of the invention, which scope is to be accorded the broadest interpretation of the appended claims so as to encompass all equivalent assemblies and methods.