Abstract:
A web-handling machine frame, at least partially built from reconfigurable interconnected blocks having precision alignment points. From such blocks, modular equipment web-handling lines for web-handling operations can be constructed ad hoc with their shaft mounted web-contacting devices in tram without the need for separate alignment procedures.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a national stage filing under 35 U.S.C. 371 of PCT/US2012/052742, filed Aug. 29, 2012, which claims priority to Provisional Application No. 61/530,579, filed Sep. 2, 2011, the disclosure of which is incorporated by reference in its/their entirety herein. 
    
    
     The present invention is related to an apparatus for manipulating a web of material having indefinite length. 
     BACKGROUND 
     Today many products include a manufacturing step where a web of indefinite length material is changed in some fashion while being conveyed between an unwind station and one or more wind-up stations. These are sometimes called “roll-to-roll” processes. Between the unwind and the wind-up, the web is conveyed along a web path, the web path usually including driven and/or idler rollers. There are numerous processes that can be undertaken to convert the web while it is being conveyed along a web path, including coating, printing, laminating, slitting, and many others. 
     SUMMARY 
     A difficulty in carrying out roll-to-roll processes is avoiding wrinkles, folds and other web disruptions while the web is being conveyed. The moving web endures frictional contact when it passes over a roller, and wants to align itself to the moving surface of the roller. It is understood that parallelism between web contacting rollers is important for minimizing wrinkles and other defects as the web is conveyed. Rollers with a high degree of parallelism between their respective axes are said by those of skill in the art to be “in tram and level.” 
     Because of this need some roller mounts are made to be adjustable, and elaborate optical, laser, mechanical, or inertial equipment are commonly used to set up web-contacting devices such as rollers with high degrees of parallelism. Once an entire web line has been placed in tram and level, sometimes tapered pins are used to secure the adjustable mounts into position. 
     A discussion of the mechanics of moving webs is present in, “Buckling of Orthotropic Webs in Process Machinery;” J. K. Good, J. A. Beisel;  Proceedings of the Seventh International Conference on Web Handling , pp 133-149 2003. Using the mathematical techniques therein, an analysis of a selection of web materials with a range of thicknesses, widths, and web span lengths was carried out to determine the degree of roller parallelism needed to avoid wrinkles. It was determined that roller parallelism to about 0.004 radian is required to handle many common web-handling situations, and parallelism within 0.0005 radian or even within 0.0001 radian, is needed for certain demanding applications such as handling thin metal foil material. The need for such precision makes difficult and expensive setting up a short production run or an experimental apparatus. 
     It has now been determined that modular equipment can be fabricated such that web-handling lines for converting operations can be constructed ad hoc with their web-contacting devices (such as rollers) in tram and level without the need for separate alignment procedures. The modular equipment is constructed from small component modules in the form of reconfigurable blocks that can be stacked and assembled in a variety of configurations to suit the particular requirements of an experiment or short production run. When the shafts of shaft-mounted web-contacting devices are disposed within certain precision alignment points on the blocks, the web-contacting devices are consistently in tram and level without further adjustment. 
     One or more advantages are associated with embodiments of the invention. The modular nature of the reconfigurable blocks allows temporary set-ups to be constructed for specialty manufacture or experimental runs. Since the precision alignment points are in fixed positions on the reconfigurable blocks, shaft-mounted web-contacting devices can be mounted quickly and directly without needing adjustment. Further, the time and expensive ancillary equipment involved in placing conventional web-contacting elements in tram is avoided. 
     Hence, in one aspect, the invention resides in a web-handling machine frame, comprising: at least two reconfigurable interconnected blocks, and each reconfigurable interconnected block comprising at least three sides and two faces, and at least one bore within at least one of the faces; at least two sides of each reconfigurable interconnected block having a precision alignment point; the precision alignment point comprising an aperture connecting the alignment point to the bore; and at least one shaft, the shaft being disposed within and releasably attached to one of the precision alignment points of each of the two reconfigurable interconnected blocks. 
     In a second aspect, the invention resides in a web-handling machine frame comprising: at least two reconfigurable interconnected blocks wherein each reconfigurable interconnected block has at least two precision alignment points; and at least two shaft-mounted web-contacting devices each having an axis of rotation; and when the shafts of the web-contacting devices are positioned in the precision alignment points of each reconfigurable interconnected block, the web-contacting devices are in tram and level to within 0.004 radian. 
     In any of the embodiments, the positioning of at least some of the precision alignment points, both on a given reconfigurable block and on an assembly built up from a number of reconfigurable blocks, allows axes of shafts disposed within the precision alignment points to be at the vertexes of a regularly spaced grid associated with a plane. That plane is conveniently parallel to one of the faces of the reconfigurable blocks. In some embodiments, the grid will be rectilinear with two perpendicular axes, with the vertexes spaced a predetermined distance apart, or a multiple of that predetermined distance, conveniently in both of the perpendicular axes. The predetermined distance can be conveniently 3 inches (7.62 cm), although values such as 1, 2, 3, 4, and 5 or more inches, or any values in between can be used or predetermined distances and spacing in any convenient unit can be selected such as centimeters. 
     In any of the embodiments, when a second shaft is disposed within and releasably attached to a second one of the precision alignment points, the two shafts are in tram and level without needing further adjustment. With properly constructed blocks, a web-handling machine frame, or a module forming a portion thereof, can be built up from numerous blocks, e.g. between about 2 to 500 or more, or between 10 and 100 interconnected blocks, and support the shafts of several web-contacting devices such as 2, 3, 4, 5, 6 or more, all of which are in tram and level without further adjustment. 
     An analysis of stacking using the Root Sum of Squares (RSS) method indicates that a spacing accuracy of precision alignment points to within ±50 microns would maintain parallelism between shafts to within 0.004 radians throughout a machine frame having dimensions up to 760 inches or more on a side. A spacing of precision alignment points accurate to within ±5 microns would maintain parallelism between shafts to within 0.0001 radians throughout a machine frame having dimensions of up to 50 inches or more on a side. This more restrictive alignment criterion could encompass a machine built up from 200 or more modular interconnected blocks. Thus, in any of the embodiments, the spacing accuracy of the precision alignment points can be within ±50 microns, ±25 microns, ±10 microns, ±5 microns, or even ±2.5 microns. In any of the embodiments, it is desirable if the web-contacting devices are in tram and level to within 0.004 radian, within 0.001 radian, within 0.0005 radian, within 0.00025 radian, or within 0.0001 radian. A further discussion of the RSS method may be found in “Review of Statistical Approaches to Tolerance Analysis;” S. D. Nigam, J. U. Turner;  Computer - Aided Design , Vol. 27, No 1, pp. 6-15, 1995. 
     Unless expressly defined herein, the terminology used to describe the embodiments of the invention will be understood to have the same meaning attributed to them by those skilled in the art. In particular, as used herein, “shaft-mounted, web-contacting devices” include but are not limited to driven and idler rollers, rolling encoders, printing rollers, embossing rollers, laminating nips, heat transfer rollers, slitter rollers, spreading rollers or spreading bars, steering rollers and microflexo rollers. Further, the definition of “shaft-mounted, web-contacting devices” is not limited to devices having a single through shaft, but also to devices having partial shafts or having spherical or toroidial mounts. Also included in the definition are live shaft rollers supported by bearings disposed within the precision alignments points. Also included in the definition are non-rotating elements that are disposed to intentionally contact the moving web as it transverses along a web path in a converting machine or other web handling machine. Similarly, non-contacting elements, such as dryers, non-contacting sensors or other devices could be supported by shafts disposed within the precision alignments and positioned very accurately adjacent to the moving web. 
     Those skilled in the art will more fully understand the nature of the invention upon consideration of the remainder of the disclosure, including the Detailed Description, the Examples, and the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In describing the embodiments of the invention, reference is made to the various Figures in which the features of the depicted embodiments are identified with reference numeral with like reference numerals indicating like structures and wherein: 
         FIG. 1  is a perspective view of an embodiment of one of the reconfigurable blocks used to form a web-handling machine frame according to the present invention; 
         FIG. 2  is a side view of two reconfigurable blocks having a square face, bound together; 
         FIG. 2   a  is a side view of two alternative reconfigurable blocks having a square face, bound together; 
         FIG. 3  is a side view of several alternative reconfigurable blocks having a square face, but with the precision alignment points positioned at the corners of the square, bound together; 
         FIG. 4  is a side view of several reconfigurable blocks having a triangular face, bound together; 
         FIG. 5  is a side view of several reconfigurable blocks having a hexagonal face, bound together; 
         FIG. 6  is a perspective view of a specialized reconfigurable block suitable for binding a group of reconfigurable blocks to a solid base; and 
         FIG. 7  is a perspective view of a web-handling station; 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to  FIG. 1 , a perspective view of a reconfigurable block  20  is illustrated. The reconfigurable block  20  has two faces  22  and  24 , and in this embodiment four sides  26 ,  28 ,  30  and  32 . The depicted block is constructed generally as a right parallelepiped, but the artisan will readily perceive that the invention is workable with blocks with faces of other shapes such as rectangles, parallelograms, triangles or hexagons, as will be discussed below in connection with  FIGS. 3 ,  4 , and  5 . At least one bore  34  is present in face  22 , and in this embodiment the bore  34  is a through bore that extends all the way to face  24 , but reconfigurable blocks  20  having blind-end bores are also suitable. In some embodiments, the bore can be quite large and not necessarily round and could be described alternatively as an opening when more than one precision alignment point is present on a side as shown in  FIG. 7 . As seen, some of the precision alignment points have an aperture that connects with the small circular bore and others have an aperture that connects with the large central opening. 
     In the depicted embodiment, all four sides  26 ,  28 ,  30  and  32  have a precision alignment point  26   p ,  28   p ,  30   p  and  32   p  respectively. Each of the depicted precision alignment points is partially defined by a groove  26   a ,  28   a ,  30   a  and  32   a  respectively, each having a truncated half-round shape. Each alignment point further includes an aperture  26   b ,  28   b ,  30   b  and  32   b  respectively that can be conveniently positioned at the center of the groove  26   a ,  28   a ,  30   a  and  32   a  respectively approximately halfway between the faces  22  and  24 . These apertures  26   b ,  28   b ,  30   b  and  32   b  connect their respective alignment point  26   p ,  28   p ,  30   p  and  32   p  respectively, to the bore  34 . 
     In some embodiments, only a single precision alignment point is present on at least two sides of the reconfigurable block. In other embodiments, only a single precision alignment point is present on each side of the reconfigurable block. In other embodiments, at least one side of the reconfigurable block has at least 2 precision alignment points, at least 3 precision alignment points, at least 4 precision alignment points, or at least 5 or more precision alignment points. The number of precision alignment points located on a side is not limited and can be readily selected based on the overall size of the block and the selected spacing of the precision alignment points chosen. 
     Reconfigurable blocks according to the present disclosure are conveniently made of suitable structural materials such as ceramic, polymer or metal. When a metal is used, stainless steel or aluminum is conveniently employed. More particularly 7075 T6 aluminum is perceived to be suitable. When aluminum is used, a hard coat anodizing treatment may be advantageous. 
     Referring now to  FIG. 2 , a side view of two reconfigurable blocks  20  and  20 ′ according to  FIG. 1  are illustrated bound together via a shaft  40 . The shaft  40  is held in the groove  26   a  via, e.g. a bolt  42  disposed within aperture  26   b  and threaded into the shaft  40 . In this embodiment the grooves, e.g.  26   a , have a truncated half-round shape. Conveniently, the grooves  26   a  are truncated 0.01 inch (0.25 mm) from being completely half-round in cross section. The shaft is precision ground to a radius equal to the radius of the groove and with a similar tolerance. The shaft  42  can be the supporting shaft of shaft-mounted web-contacting device, or it can be a very short shaft with no other purpose than binding reconfigurable blocks  20  and  20 ′ together. 
     Because the groove  26   a  is not a complete semi-circle, the sides of the two reconfigurable blocks  20  and  20 ′ are separated by a gap  44 . The gap is conveniently approximately 0.02 inch (0.5 mm), but this is not a critical dimension as long as it is large enough to avoid over constraining the position of the precision alignment points. In this embodiment, the accuracy of the relative placement of the two reconfigurable blocks  20  and  20 ′ is contingent upon the accuracy of the spacing of the grooves, e.g.  26   a  and the accuracy of the diameter of the shaft. An advantage realized from this approach is that wear and tear to the sides, e.g.  26 , of the reconfigurable block  20  when being reused numerous times does not ruin the accuracy of the relative placement. Further, it allows a given reconfigurable block  20  to be easily removed from an assembled field of numerous reconfigurable blocks when desired. Because of the gaps between each of the reconfigurable blocks, less disassembly of the web-handling machine frame is required to significantly change the resulting web path when inserting or removing shaft-mounted web-contacting devices. 
     While most shaft-mounted web-contacting devices used in web-handling have round shafts, and the illustrated embodiment in  FIG. 2  and elsewhere have round shafts, this is not considered a requirement of the invention. For example, shaft-mounted web-contacting devices could be manufactured with square or triangular shafts, and precision alignment points with square or triangular grooves could be fabricated to receive them. Additionally, triangular or V-shaped grooves could be sized to center and align rounds shafts of web-contacting devices if desired. 
     Referring now to  FIG. 2   a , a side view of two reconfigurable blocks  20 ″ and  20 ′″ illustrated. This view is similar to  FIG. 2  in that the two reconfigurable blocks  20 ″ and  20 ′″ are bound together via a shaft  40  which is held in the groove  26   a  via a bolt  42  disposed within aperture  26   b . However, in this embodiment the grooves, e.g.  26   a , have a fully half-round shape, the shaft  40  has a diameter smaller than the groove  26   a , and the shaft need not necessarily be precision ground, but should mate with the grooves, e.g.  26   a  in a sliding fit. 
     With the described configuration, the sides of the two reconfigurable blocks  20 ″ and  20 ′″ are in contact with each other and, the shaft  40  is separated from the walls of the grooves, e.g.  26   a , by a gap  46  (the gap chosen can be a sliding fit for a given shaft size can be calculated from ANSI standard B4.2-1978). In this embodiment, the sides, e.g.  26  of the blocks  20 ″ and  20 ′″ are in contact, and the accuracy of the relative placement of the two reconfigurable blocks  20 ″ and  20 ′″ is contingent upon the accuracy of the placement of the sides, e.g.  26  of the blocks  20 ″ and  20 ′″. An advantage realized from this approach is that the dimensional accuracy of the grinding of the shaft  40  is not as critical insofar that the gap  46  does not result in a misalignment of the shaft  40  greater than an angle of 0.004 radians or even 0.0001 radians for demanding applications. 
     Referring now to  FIG. 3 , a side view of several alternative reconfigurable blocks  47  bound together at their precision alignment points, e.g.  26   p , is illustrated. Reconfigurable blocks  47  have a square face shape with two faces and four sides, but in contrast with reconfigurable blocks  20  of  FIG. 1 , the precision alignment points, e.g.  26   p , are positioned at the corners of the square rather than along the edges. Some of the reconfigurable blocks  47  are bound together via shafts  40 . The shafts  40  are held in the grooves  26   a  via, bolts  42 . In this embodiment the grooves, e.g.  26   a , have a truncated half-round shape, and the shaft is precision ground to a radius equal to the radius of the groove  26   a  so that adjacent reconfigurable blocks  47  are separated by a gap  44 . 
     Referring now to  FIG. 4 , a side view of several alternative reconfigurable blocks  48  bound together at their precision alignment points, e.g.  26   p , is illustrated. Reconfigurable blocks  48  have a triangular face shape with two faces and three sides, with the grooves  26   a  of the precision alignment points  26   p , positioned at the centers of the triangle&#39;s edges. Some of the reconfigurable blocks  48  are bound together via shafts  40 . The shafts  40  are held in the grooves  26   a  via, bolts  42 . In this embodiment the grooves, e.g.  26   a , have a truncated half-round shape, and the shaft is precision ground to a radius equal to the radius of the groove  26   a  so that adjacent reconfigurable blocks  47  are separated by a gap  44 . 
     Referring now to  FIG. 5 , a side view of several alternative reconfigurable blocks  49  bound together at their precision alignment points, e.g.  26   p , is illustrated. Reconfigurable blocks  49  have a hexagonal face shape with two faces and six sides, with the grooves  26   a  of the precision alignment points  26   p , positioned at the centers of the hexagon&#39;s edges. Some of the reconfigurable blocks  49  are bound together via shafts  40 . The shafts  40  are held in the grooves  26   a  via, bolts  42 . In this embodiment the grooves, e.g.  26   a , have a truncated half-round shape, and the shaft is precision ground to a radius equal to the radius of the groove  26   a  so that adjacent reconfigurable blocks  47  are separated by a gap  44 . 
     The artisan will observe that the reconfigurable blocks of embodiments of  FIGS. 1-5  have some degree of rotational symmetry. This is can be a great convenience with respect to flexibility in building up a web-handling machine frame, but is not considered a requirement of the invention. The thickness of the reconfigurable blocks is not critical as long as that thickness is sufficient to allow a firm placement for each reconfigurable block against an adjacent reconfigurable block, or against a shaft to align it as required. A thickness of approximately 1 inch (2.54 cm) is considered suitable for many embodiments. Thinner or thicker blocks can be used for other embodiments. 
     Referring now to  FIG. 6 , a perspective view of a specialized reconfigurable block  50  is illustrated. Reconfigurable block  50  is particularly suited to bind a group of reconfigurable blocks according to the invention to a fixed base such as a rail, optical breadboard, or base plate of a web-handling line. The reconfigurable block  50  has two rectangular faces  22  and  24 , and in this embodiment four sides  26 ,  28 ,  30  and  32 . Four bores  34  (typical) are present in face  22 , and in this embodiment the bore  34  is a through bore that extends all the way to face  24 . 
     In the depicted embodiment, only three sides  26 ,  28 , and  32  have a precision alignment points  26   p ,  28   p , and  32   p  respectively, each comprising a groove  26   a ,  28   a , and  32   a , and an aperture  26   b ,  28   b , and  32   b  respectively, connecting one of the bores  34  to one of the grooves  26   a ,  28   a , and  32   a . Conveniently, each groove  26   a ,  28   a , and  32   a  has a truncated half-round shape. Several counter-bored through holes  52  are present to allow bolts to be used to bind reconfigurable block  50  to a support base. 
     Web-handling lines are typically constructed of multiple stations which may be separated by distances on the order of meters but whose shaft-mounted web-contacting devices must nonetheless be in tram and level with each other. Referring now to  FIG. 7 , a perspective view of a web-handling station  60  is illustrated. Arbitrarily, for purposes of showing an assembly of reconfigurable blocks supporting actual web-handling apparatus, the web-handling station  60  being illustrated comprises a cantilevered unwind stand  62 , a dancer roller assembly  64 , and a pair of idler rollers  66  and  68 . The web-handling station  60  includes not only unit sized blocks  20 , but also larger reconfigurable blocks  70  and  72 . Reconfigurable blocks  70  and  72  have more precision alignment points, e.g.  26   a , than the unit blocks  20 , but the spacing of these precision alignment points in the rectilinear grid previously discussed is the same predetermined value as the unit blocks  20  and accurate to the same degree. 
     The web-handling station  60  is shown assembled with a long tie shaft  74  (mounted in precision alignment points  26   p ) and a long tie shaft  76  (mounted in precision alignment points  30   p ), that span the distance between reconfigurable blocks  70  and  72 . Another long tie shaft  78  spans the distance between unit sized reconfigurable blocks  20  mounted on reconfigurable block  70  and unit sized reconfigurable blocks  20  mounted on reconfigurable block  72 . Short tie shafts  80  are also present in diverse locations to attach some of the unit sized reconfigurable blocks  20  together. The long tie shafts  74 ,  76 ,  78  and the short tie shafts  80  can be used to keep the reconfigurable blocks  20 ,  70 ,  72  in precise parallel alignment with each other. 
     Thus, a typical web-handling line or module made from the reconfigurable blocks will include two side frames generally made up from several reconfigurable blocks but each side frame could simply be one very large reconfigurable block for a small module. The web-handling line or module will also generally include short tie shafts or stub shafts that do not span from one side frame to the next but the join adjacent reconfigurable blocks, and long tie shafts that join the two side frames such that they are spaced parallel to each other at a predetermined distance. The spacing between the side frames is generally determined by the width of the web and the necessary clearance of the web to each of the side frames. Finally, the web-handling line or module generally includes one or more shaft mounted web-contacting devices and possibly one or more shaft mounted non-web contacting devices disposed in the precision alignment points of each side frame. 
     When web-handling station  60  is connected to another station employing the inventive reconfigurable blocks positioned before web-handling station  60  by one or more precision alignment points  32   p , and connected to another station employing the inventive reconfigurable blocks positioned after web-handling station  60  by one or more precision alignment points  28   p , any shaft-mounted web-contacting devices on the up-web and the down-web stations will be reliably in tram and level. 
     The unwind stand  62  includes a drive unit  90  for controlling the rotation of a spindle  92  that engages, e.g. the core of roll of indefinite length material. This illustrates that a web-handling element can be successfully mounted in a cantilevered fashion to one or more reconfigurable blocks ( 72  in this case). The dancer roller assembly  64  includes a dancer roller  94  rotatably mounted on swing arms  96  and  98  which are in turn pivotally mounted on a tie shaft  100 . Tie shaft  100  is in turn positioned within precision alignment points  26   a  on reconfigurable blocks  70  and  72 . Web tension controllers  102  and motion stops  104  of conventional type are present. This illustrates that a shaft-mounted web-contacting device such as dancer roller  94  can be placed in tram and level vicariously, in this case drawing on the precision placement of tie shaft  100  relative to reconfigurable blocks  70  and  72 . 
     Other modifications and variations to the present disclosure may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present disclosure, which is more particularly set forth in the appended claims. It is understood that aspects of the various embodiments may be interchanged in whole or part or combined with other aspects of the various embodiments. All cited references, patents, or patent applications in the above application for letters patent are herein incorporated by reference in their entirety in a consistent manner. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description shall control. The preceding description, given in order to enable one of ordinary skill in the art to practice the claimed disclosure, is not to be construed as limiting the scope of the disclosure, which is defined by the claims and all equivalents thereto.