BACKGROUND OF THE INVENTION:

FIELD OF THE INVENTION:

This invention relates to the cross-machine cutting of a traveling continuous web, such as paper being produced on a paperma ing machine. More particularly, this invention relates to the cross-machine cutting of a traveling web in conjunction with the turn-up at the reel on a papermaking machine. Still more particularly, this invention relates to the cross- machine cutting of a traveling continuous web by utilizing a pair of water jets traveling simultaneously over the web in opposite directions, all in conjunction with the turn-up of the web onto a core for winding into a roll.

DESCRIPTION OF THE PRIOR ART:

Prior apparatus for severing the traveling paper web in a papermaking machine near the reel for the purpose of creating a new leading edge to be wound onto a new core, or reel spool, generally utilize a means, such as a knife, blade, rod, or the like, to puncture the web and use the tear to establish the leading edge of a relatively narrow strip, or tail, which is secured to a new core to begin winding thereon. The width of the newly established strip is then broadened, by being torn away from the on-going portion of the web, to eventually become the width of the traveling web at which time the entire web begins being wound onto the new core. The portion of web which travels downstream past the point where the strip is created continues to be wound on the preceding roll. Often, the particular prior art technique used to cut the web across its full width depends on the grade of paper being produced.

For relatively lightweight paper webs, which is to say most paper other than board grades, a preferred way to effect the cross-machine severance of the traveling continuous web and to produce a new leading edge is to slash the web transversely near its center for a short distance, such as 20-30 cm. Downstream of the slash cut, a source of pressurized air is directed against the web at a point aligned with the slashed cut. Air is thus projected beneath the web as it is supported over the surface of the reel drum to produce a narrow leading edge of a new strip segment of the web at the slash cut as the pressurized air beneath the web urges the initial cut to continue tearing at its edges. A curved guide is positioned slightly downstream of the strip segment as it is tearing outwardly away from the on-going web and urges the strip to travel in a curved path over the surface of a new core which has been positioned parallel over the reel drum. The momentum of the traveling strip causes it to circumvent the new core which is brought into nipping engagement against the reel drum. Once the strip becomes nipped against the reel drum, further tearing of the web outwardly toward the edges is positively effected by rotation of the core and a new full width roll begins being wound as soon as the strip has widened outwardly to its front and back edges.

This type of creation of a new roll of paper does not work well, if at all, on the various board grades of paper. In board grades, the cut strip, or tail, tends to continue tearing in the machine direction, and the torn edges do not tend to migrate laterally toward one or either of the front and back edges of the web.

A common procedure for cutting board grades in the cross-machine direction on a newly wound roll and to commence winding the traveling web into a new roll is accomplished by passing a strong, flexible band, or

ribbon, such as tape, through the board from one edge to the other. While this procedure works, it has several deficiencies. First, it requires considerable time and skill by an operator who must secure the far end of the tape to the back side of a core, which is dangerous, and the front end to a support, such as the reel frame. Further, the tape must be both strong enough to tear through the heavy board as well as be repulpable when the tape wound onto the new core during the cutting procedure is eventually discarded in the broke pit with the wasted paper produced by the spiral cut. Tape with these properties is very expensive. Finally, during the board cross-cut procedure, the tape is wound spirally onto the core which produces a relatively long spiral path on its surface. This produces a long diagonal cut in the web of corresponding length extending in the cross-machine direction. Thus, the board on either side of the diagonal cut is not full web width. It is wasted and must be repulped.

Regardless of which of the foregoing prior techniques was utilized to cut the traveling paper web in the cross-machine direction, any such cut which tore the paper was ragged and not smoothly continuous with defined edges in a predetermined, substantially uniform outline. The cut did not extend substantially in the cross-machine direction, and the cut could not easily be made in board grades of the paper product. Also, a substantial amount of waste was generated due to the non-symmetrical winding onto the new spool when a tape is pulled through the web from one edge to the other, requiring many wraps of the web around the spool before the web is again suitable for sale.

SUMMARY OF THE INVENTION:

The deficiencies with the described prior techniques for cross-cutting a traveling paper web have been obviated by this invention. In this invention, a pair of high

pressure water jets are mounted over the traveling web upstream of the reel drum. The water jets are initially positioned at the center of the traveling paper web and are aimed at the same point on the web surface. The water jets are mounted to move transversely in opposite directions from their initial position over the center of the web. Their transverse movement results in a symmetrically cut web being wound onto the new core or spool.

When it is desired to cross-cut the traveling web, the co-acting water jets are activated to puncture a small hole in the web and immediately begin their transverse movement in opposite directions toward the side edges of the traveling web. The water. jets cut the paper web, regardless of the grade of paper or board, with very little waste and with very clean, relatively precisely defined edges. As viewed from the top, the shape of the cut is in the form of a very shallow "V". The precise shape is a function of the water jets transversing speed relative to the web speed. Due to the speed of the traversing water jets, the distance in the machine direction from the initial piercing of the web at the bottom of the "V" to the edges of the web where the cut ends, in the direction of web travel, is relatively short. Further, each such cut in the web for successive cores to be wound into new rolls of paper has the same symmetrical pattern.

Since the traversing speed of the water jets is relatively fast, no tearing of the web occurs as it is urged by a stream of compressed air onto, and to circumvent, a new core to be wound into a new roll of paper. This facilitates the application of the stream of compressed air to the leading "V"-shaped end of the cut web to redirect it onto a new core to begin winding the on-coming web into a new roll of paper.

Accordingly, it is an object of this invention to provide a method and apparatus to produce a clean cross¬ cut in a traveling paper web regardless of the paper grade.

It is another object of this invention to provide a method and apparatus to produce substantially uniform cross-cuts in conjunction with a turn-up onto a core in a traveling paper web.

It is an object, feature and advantage of this invention to provide a method and apparatus for producing cross-cuts in a traveling paper web which result in little waste.

A feature of this invention is the provision of two water jets which cooperate to produce the cross-cut in a traveling paper web.

It is another feature of this invention to provide two water jets which produce the cross-cut in the traveling paper web by traveling in opposite directions.

Another feature and advantage of this invention is to provide a method and apparatus for effecting a cross-cut in a traveling paper web wherein no tape or flexible band is used.

Still another object, feature and advantage of this invention is to provide a method and apparatus for efficiently cross-cutting a traveling paper web in conjunction with effecting a turn-up of the web onto a core to be wound into a roll.

These, and other objects, features and advantages of this invention will become more readily apparent to those skilled in the art upon reading the description of the

preferred embodiment in conjunction with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a side-elevational view of a prior art configuration for initially piercing the web and applying pressurized air to enable the web to tear itself in the cross-machine direction to cross-cut the traveling web.

Figure 2 is a plan view showing the pattern of the cross-cut in the traveling web as produced by the apparatus shown in Figure 1.

Figure 3 is a plan view of the traveling web showing an exemplary pattern of the cross-cut produced in the traveling paper web by the method and apparatus of this invention.

Figure 4 is a side-elevational view of the reel in a papermaking machine and showing the water jet web cutting apparatus of this invention.

Figure 5 is a side-elevational view of the water jet apparatus shown in view "A"-"A" in Figure 4.

Figure 6 is a plan view of the water jet apparatus shown in Figure 5 and illustrating the traversing movement in opposite directions of the two water jets.

DESCRIPTION OF THE PREFERRED EMBODIMENTS:

Referring to Figure 1, which shows a prior art configuration, a papermaking machine reel, generally designated as 10, includes a frame 12 with a reel drum 14 in nipping engagement with a roll of paper 16 being wound with the on-coming traveling web W. A web slasher 18 is positioned above the web in a taut span between a guide roll 20 and the reel drum. The web slasher, which may take the form of a knife blade or a relatively stiff rod.

is positioned near the center of the traveling web. When it is desired to cross-cut the web, the slasher is brought _^ downwardly into the web and moved laterally a short distance to make a short lateral cut in the web, which typically is about 20-30 cm in length, as shown at 22 in Figure 2. At this time, a new core, or spool, 24 is brought downwardly into nipping engagement with the traveling web over the reel drum 14. A so-called goose-neck 26, which comprises a curved plate, directs a stream of compressed air from a source, such as a compressed air pump 28, against the traveling web over the cut 22 near the middle of the web over the reel drum. The stream of compressed air enters the cut 22 and pushes the cut edge of the web upwardly to cause the web to tear outwardly toward the edges 30,32 of the web in a relatively ragged pattern shown, by way of illustration, by edges 34,36 and 34',36' in Figure 2. The torn edge is a randomly created phenomenon which is influenced by web properties, particularly directionality. At times, the web tear proceeds essentially in the machine direction, such as shown at 34",36", which requires the turn-up of the web onto a core, or spool, be aborted in order to avoid having only a narrow width of the web being wound onto a new core.

Still referring to the prior art shown in Figure 2, the jagged edges 34,36 and 34' ,36* of the tear on each side of the initial cut 22 travels a relatively long distance D^ in the machine direction 38 before it reaches the outer edges 30,32 of the traveling web. All of the paper, or board, for the full width of the web W along the distance D^ is thus wasted.

In this description, corresponding elements in the various configurations will be correspondingly numbered with different letter postscripts to differentiate between them. Similarly, similar elements within the same

configuration will be differentiated with prime superscripts.

Referring to the invention shown in Figures 3-6, the prior art slasher has been replaced by a pair of high pressure water jets 40,42. These water jets are attached to an angle bracket 44 which, in turn, can be pivotally attached to a frame member 46, if desired, such that a hydraulic piston 48 having one end 50 pivotally attached to the frame member and the other end 52 pivotally attached to the bracket enables the angle bracket to pivot in the direction of arrow 54 about pivot 56 so as to bring the water jets into and out of position over the traveling web W.

Each water jet is mounted to a full width beam by a traversing mechanism 58,60, respectively, which need not be of any particular type. In the preferred embodiment, the traversing mechanisms comprise an endless belt 62,64 which is disposed about a pair of spaced sprockets (not shown) which, in turn, are driven by a motor 66,68, in a well known manner which need not be discussed in further detail. The individual water jets 40,42 are attached to a corresponding looped belt 62,64 for traversing movement in the direction of arrows 70,72 which are at right angles to the direction of web travel 38. Although individual motors and traversing belts have been shown, it is envisioned that a single belt driven by a single motor could perform the traversing operation simply by attaching one water jet to the looped drive belt on one span between its spaced-apart sprockets, and attach the other water jet to the looped belt on the other span between the spaced sprockets.

As shown in Figure 4, a gooseneck 26a is pivotally mounted in the frame 12a so as to be capable of pivoting into and out of arcuate proximity with a new core 24a which is positioned over the reel drum 14a when the roll

of paper being wound reaches a predetermined diameter and the web is desired to be cross-cut and have its leading end wrapped onto a new core. This core wrapping procedure is commonly referred to as a "turn-up".

In operation, a web is initially produced on the papermaking machine and run through the entire machine to establish a steady state of operation. The web is typically doctored off the reel drum by doctor 23 and dumped into a broke pit until normal operation and production of wound rolls begins. When it is desired to begin winding rolls of commercially acceptable paper, a core, or reel spool, 24a is brought up to a circumferential speed which matches the web speed over, and spaced above, the reel drum 14a and is then moved in the direction of arrow 88 to the turn-up position where the reel spools surface makes contact with the traveling web on the reel drum.

The water jets 40,42 are initially pivoted downwardly toward the traveling web W and aimed at the same spot 76 near, or at, the center of the traveling web. When the cross-cut is to be made, the water jets are activated, and their high pressure streams 75,75' of water cooperate to pierce a hole 77 in the web at 76. Immediately, the traversing mechanisms are actuated by motors 66,68 to move belts 62,64 in the direction of arrows 70,72. This produces a rapidly formed cut 80,82 in the web extending outwardly toward the outer edges 30,32 of the web.

A gooseneck 26a, which generally comprises a curved metal plate, is pivoted downwardly in the direction of arrow 74 to partially encircle a new core. It has a source of compressed air, such as pump 28a, associated with it to direct a stream of compressed air about the inner periphery of the gooseneck in the direction of arrow 84.

Soon after the cut is made in the middle of the web, the air stream traveling about the inner periphery of the gooseneck, which is positioned over the center of the web, is projected toward the cut in the direction of arrows 78 (Figures 3 and 6) to urge the leading edge of the cut sheet to travel upwardly and away from the traveling web over the surface of the reel drum and onto, and about, the new core 24a as will be understood more clearly in conjunction with Figure 4. Since the water jets travel in opposite directions 70,72, and can travel at selectively relatively high or low speeds, which might, for example, be 2-3 times the web speed, the web W is cut quite cleanly by the high pressure stream of water from each of the water jets in a symmetrical pattern, such as a shallow "V" shaped pattern (Figures 3 and 6) , which extends to the outer edges 30,32 of the web W. Due to the speed of the oppositely traveling water jets, and the repetitive, predictable operation of the traversing mechanism, the shape, or pattern, of the cut is quite uniform. Even more important, the pattern is symmetrical about the web centerline. Therefore, there are no disruptive forces, such as would be present in the case of a tape initially engaging the web at one edge to make a cross-cut. Stated another way, the forces cutting the web begin at the center of the web and engage the web substantially uniformly and proceed in opposite directions so that the web is not urged laterally to its direction of travel during the cross-cutting operation. The air assisted gooseneck thus operates to wrap the center cross-cut portion of the on-coming web onto a new core to begin wrapping the new core into a wound paper roll. When the center-initiated cuts have been guided to the corresponding edges of the web by the oppositely traveling water jets, the preceding roll of paper is finished being wound.

Once the web has been completely cross-cut across its transverse width, which, of course, occurs in a relatively

short time, the newly created leading edge of the web is wrapped onto a new core to commence the winding of a new roll of paper. The trailing end of the cross-cut web continues to be wound on the preceding roll of wound paper 16a_ which then is moved out of the way in the direction of arrow 86, and the new roll of paper is rotated downwardly in the direction of arrow 88 to continue winding the web thereon as the wound roll is nipped against the reel drum 14a.

After the newly cross-cut leading edge of the web has begun being wound onto a new core, the gooseneck is rotated outwardly away to allow the newly started core to be rotated downwardly into steady state winding position.

Naturally, it is envisioned that variations in the apparatus and method of the invention can be made without departing from the spirit of the invention and scope of the claims. For example, the web can be supported in a variety of ways. In the preferred embodiment described, the web W is supported in a taut span between a guide roll 20a and the reel drum 14a as it is cut by the water jets. The web is also supported over the surface of the reel drum. However, the web could just as well be supported by a flat plate, with or without a slot opposite the hole 77 pierced in the web, beneath the web in the span between guide roll 20a and the reel drum.

Another contemplated variation, as mentioned previously, is that the traversing mechanism could comprise a single looped belt driven by a single motor with the high pressure water jets mounted on the belt on opposite sides of the loop in order to provide traversing movement in opposite directions.

In the operation of the water jets, while it is preferred that the two water jets co-act together to be aimed at the same spot on the surface of the web to pierce

the web together with their water jet streams, it is contemplated that one water jet could be operated to pierce the web with its stream and the other water jet operated to begin its lateral cutting action from the hole pierced by the first water jet stream by projecting its water jet stream into the hole in the web a fraction of a second later. The term "spot" then is used to connote substantially the same point, or area, where the web is pierced to initiate the cut whether by one or more water jets. It is also contemplated that the water jets could be positioned above or below the web.

Finally, both the speed and the direction of the water jets can be controlled to further minimize the waste produced by the distance D^ of the paper between the initial puncture of the web and the downstream point where the cross-cut reaches the outer edges of the traveling web.