Patent Application
20060078714
The present invention relates generally to paper slitting machines, and, more specifically, to end-of-roll warning stripes printed therein.
The ubiquitous paper roll is found in various sizes for various applications including cash registers, ATM machines, adding machines, and receipt printers. Each roll typically includes a paper or plastic core around which is wound a continuous ribbon of paper.
Paper rolls are typically produced in a slitting machine in which a large mill roll of paper is mounted at one end of the machine, unwound through the machine, and then slit at numerous locations along its width to provide corresponding ribbons which are then wound on corresponding cores commonly mounted on a supporting arbor or mandrel. The slitting operation is effected by a pair of circular knives or blades which slit the web in a typical shear cut for each of the cores.
In a single production run of paper cores, several cores are mounted coaxially around the supporting arbor in longitudinal abutting contact, and fixedly mounted on the arbor by end fittings or nuts. The arbor is then mounted in the slitting machine.
The slitting blades in the machine are typically arranged in pairs on opposite sides of the paper web with the corresponding cutting or shearing lines thereof being suitably aligned with the respective joints between the cores on the arbor.
In one conventional slitting machine, a row of first circular slitting blades are mounted on a first shaft on one side of the web. The first blades are separated from each other by corresponding precision spacers and thin shims as required to precisely align the cutting edges of the first blades with the corresponding joints between the cores.
A set of second circular blades are pivotally mounted on a second shaft in the machine to selectively engage or disengage the corresponding first blades. Each of the second blades is conventionally mounted in a supporting holder which may be adjusted in position along a supporting dovetail attached to the second shaft. The individual holders may then be adjusted along the dovetail for properly engaging the second blades with their first blade counterparts to control the precise width of each ribbon slit from the web, and also control the cutting overlap or depth between the pairs of first and second blades.
Each production run of paper cores requires the set up of the individual cores on the arbor, alignment thereof with the first blades, and corresponding alignment of the second blades with the first blades, and takes considerable time. Since the first and second blade sets are integral parts of the slitting machine itself, and the arbor must be suitably mounted therein, the slitting machine cannot be operated during the set up procedure which correspondingly reduces the throughput of the machine, and therefore affects cost of operation.
Adding to the set up process for a particular batch run of paper rolls is the alignment required for printing end-of-roll warning stripes. At the commencement of each production run, the leading edge of each ribbon is initially tucked around the empty core and a warning stripe is printed for a short portion of the roll length, for example about three feet. In this way, when the roll is later depleted in use by the user the end-of-roll warning stripe will be visible as the ribbon is dispensed from the printer to alert the user that the paper roll requires changing.
The warning stripe is typically printed in the slitting machine with a suitable color ink in a narrow vertical stripe along one or both edges of the paper roll. This is typically effected by using an inking wick which bridges each of the ribbon slits for simultaneously printing warning stripes along the common slit of the adjoining ribbons. In this way, each ribbon will have a vertical warning stripe printed solely along each edge of the ribbon for the short length of about three feet.
In another conventional slitting machine, the warning stripe may be printed using individual printing rollers which bridge the respective ribbon slits for printing the stripe along the common edges of the ribbons at the slit line. The individual rollers have a hub with a set screw that permits their lateral adjustment along the length of a common supporting shaft.
In either configuration, the printing wicks or the printing rollers must be individually aligned with the respective slit lines for the intended width of the individual rolls to be produced. The typical mill roll has a width of about 53.5 inches, and 11 to 35 rolls may be formed depending upon the standard width thereof. And, the required alignment procedure to print the warning stripes along the several slit lines increases the down time of the machine, and correspondingly increases cost of the paper rolls.
Accordingly, it is desired to provide an improved slitting machine in which downtime for set up of each production run may be minimized for maximizing use of the machine.
A slitting machine includes a stand for supporting a web which is slit into multiple ribbons by a plurality of blades, with the ribbons being wound on corresponding cores supported on an arbor. A common ink roller is mounted across the feedpath of the web and has a printing surface configured to print an end-of-roll warning stripe in a universal pattern bridging adjacent ribbons irrespective of individual width thereof.
The invention, in accordance with preferred and exemplary embodiments, together with further objects and advantages thereof, is more particularly described in the following detailed description taken in conjunction with the accompanying drawings in which:
Illustrated schematically in
A mandrel or arbor 16 is suitably rotatably mounted at an opposite end of the machine at the end of the feedpath for the web for winding the ribbons around a plurality of cores 18 suitably mounted on the arbor as illustrated in
The slitting machine illustrated in
The arbor rests on a pair of bed rolls, with a riding roll resting atop the arbor. A nip roll immediately precedes the two bed rolls, and three idler rolls are located upstream in the feedpath to suitably guide the unwinding web from the mill roll into the machine for slitting thereof. A spreader roller immediately follows the last idler roll prior to slitting of the web into the multiple ribbons.
As shown in
A second shaft 28 is pivotally mounted at opposite longitudinal ends between the two endwalls 20. The second shaft is spaced laterally from the first shaft, and is parallel therewith.
A plurality of second circular knives or blades 30 adjoin respective ones of the first blades 26 and are mounted in suitable blade holders which in turn are supported on the first shaft 24. The blade holders illustrated in
The slitting machine as described above is conventional in configuration and operation and is configured to unwind the mill roll from the stand, slit the wide web into multiple narrow ribbons, and then wind the individual ribbons on the respective cores supported on the common arbor.
As indicated above, various numbers of the cores may be mounted on the common arbor depending upon the desired width of the individual paper rolls to be produced. For example, 11 to 35 cores of equal standard width may be mounted on the common arbor for producing a corresponding number of paper rolls.
Once the number of cores is determined, a corresponding number of the first blades 26 are mounted on the first shaft 24 and adjusted in lateral position to correspond with the junctions between the adjoining cores. Correspondingly, each of the second blades 30 must then be laterally adjusted along the length of the second shaft 28 for alignment with a respective one of the first blades 26.
As shown in
One conventional form of the basic slitting machine 10 is commercially available from the John Dusenbery Company of Randolf, N.J., under Model 625. Another conventional form of the slitting machine is available from the Jennerjahn Company of Matthews, Ind., under Model 1639.
In both of these conventional slitting machines, printing wicks or rollers are provided for printing an end-of-roll warning stripe over a short distance of the initial end of the ribbons as they are initially wound onto the corresponding cores. As indicated above, the alignment of the individual wicks or printing rollers increases the set up time for each production run and correspondingly reduces productivity of the machine.
As illustrated schematically in
The ink roller has an external printing surface 36 specifically configured to print an end-of-roll warning signal or stripe 38 in a universal or common pattern bridging preferably all of the full complement of individual ribbons 12b across the full width A of the web 12a irrespective of the individual width B of each of the ribbons.
In a conventional manner, the warning stripe is intermittently printed over a short length C of the web during the initial production of the paper rolls, which warning stripe then becomes visible as the individual paper rolls are later depleted during use.
The machine is conventionally configured to initially tuck the leading edge of the individual ribbons around the empty cores 18 followed in turn by the short length C of warning stripes, with the remainder of the length of the wound ribbon being clean without further printing thereon as desired.
The typical width A of the mill roll is about 53.5 inches, with the individual widths B of the ribbons having standard sizes ranging from about 1.5 inches to about 4.5 inches corresponding with 35 to 11 cores or rolls mounted on the common arbor 16. The length C of the warning stripes is about three feet in a typical roll having hundreds of feet of ribbon wound thereon.
A particular advantage of the single ink roller 34 illustrated in
As indicated above, conventional ink printing wicks or rollers require individual adjustment of their location for the specific width of the rolls to be produced. This requires substantial set up time, and corresponding loss of productivity. However, the common ink roller 34 is installed in the slitting machine only once and requires no additional set up time since its printing coverage extends across the entire width of the mill roll irrespective of the number and size of the individual rolls to be produced.
As shown in
In this way, irrespective of the individual width of the ribbons and the associated slit lines, the universal warning stripe will be printed across the full width of each of the ribbons without the need for additional alignment of the common ink roller 34 relative to the individual slit lines.
The sleeve 42 may be relatively thin and in turn mounted on a tubular metal hub 44 through which the supporting shaft 40 extends. In alternate embodiments, the ink roller 34 may be configured in any suitable manner to provide sufficient rigidity across the entire width of the web 12a, while also providing a suitable external printing surface for printing the warning stripe 38 in the desired universal pattern to bridge all of the individual ribbons being cut from the common web.
As indicated above, the sleeve 42 is preferably a non-metal material, such as rubber, which may be easily machined at low cost for producing the desired universal printing pattern, and having a suitable surface finish for transferring and printing ink.
As shown schematically in
In this way, the slitting machine may be operated in a conventional manner to selectively engage the ink roller 34 against the running web 12a to produce the warning stripes 38 across the full width A thereof and for a desired running length C at the beginning of each of the ribbons being wound on the supporting cores 18.
In the preferred embodiment illustrated in
As indicated above, the warning stripe 38 is preferably universal or common to all of the ribbons irrespective of the individual width thereof. In the exemplary embodiment illustrated in
The grooves 54 and lands 36 preferably extend obliquely or diagonally to the longitudinal centerline axis of the sleeve 42 as illustrated in
The grooves 54 as illustrated in
A particular advantage of this diagonal form of the printing lands 36 is maintaining stability of printing during the high speed operation of the slitting machine. For example, the slitting machine may be operated at throughput speeds of about 600 to about 1200 feet per minute, and correspondingly fast acceleration and deceleration times when producing paper rolls therein. Printing of the warning stripe occurs upon start up of each production batch as the machine is quickly accelerated to speed, with the warning stripe being printed for the very short initial length of the ribbons, of about three feet for example.
The diagonal printing lands 36 will smoothly engage the web 12 pressed against the underlying rotary platen 52 for maintaining printing stability and ensuring uniformly printed warning stripes. Furthermore, the supporting shaft 40 of the ink roller has a suitably large outer diameter for introducing sufficient rigidity across the full length of the ink roller to ensure uniform printing of the warning stripe across the full width of the web.
Since the common ink roller 34 may be used for printing a common or universal warning stripe over the several ribbons 12b being cut from the common web 12a, the form of the warning stripe 38 may vary as desired.
For example, the grooves 54 and lands 36a illustrated in
Alternatively, the discrete lands 36e may be rectangular or square in another uniform pattern. The discrete lands 36d,e will print corresponding uniform patterns in the warning strips across the width of the individual ribbons.
Furthermore, the various forms and patterns of the warning stripes disclosed above may also be printed using any suitable color, which is preferably lighter than the intended printing color to be used by the user so that printing by the user may still be visible notwithstanding the various forms of the warning stripe.
The various forms of the warning stripe as implemented by the corresponding forms of the printing surface of the ink roller 34 may be selected in primary part by minimizing the cost of manufacture of the ink roller 34 and the associated cost of printing the warning stripe. The ink roller should be as simple as possible for reducing its cost. The warning stripes should also be as simple as possible for reducing the amount of ink needed for printing the warning stripes.
And, the particular pattern of the printing lands may be optimized for maintaining dynamic stability of the ink roller during operation in the high speed production of the slitting machine. A smooth and stable transition of the ink roller as it engages the moving web during slitting operation, as it prints the warning stripe, and as it disengages the web during operation should be maintained.
Accordingly, the relatively simple introduction of the common ink roller instead of the several discrete printing wicks or printing rollers previously used in the high speed slitting machines disclosed above can substantially reduce set up time for slitting machines between production runs and improve the overall productivity of paper roll manufacturing.
The modified slitting machine permits an improved method of use as described above which eliminates the need for repeated alignment of the common roller with the individual slit lines for different production runs. The resulting wound paper rolls 12c shown in
While there have been described herein what are considered to be preferred and exemplary embodiments of the present invention, other modifications of the invention shall be apparent to those skilled in the art from the teachings herein, and it is, therefore, desired to be secured in the appended claims all such modifications as fall within the true spirit and scope of the invention.
