MXPA96003318A - Method and apparatus for cutting tissues above - Google Patents

Abstract

The present invention relates to a method for cutting a flat multilayer, elongated surface strip of tissue material, which comprises the steps of: advancing the strip along a linear path at a feed rate; a pair of drums mounted cantilevered on the opposite sides of the path, to flank the flat surfaces of the strip, each of the drums having a periphery and a plurality of grooves extending axially on its periphery, defining these grooves, when rotate the drums, orbits of grooves, orbit a saw blade adjacent to the path, and cyclically intersect the blade's orbit with the slitting orbits, to crosscut the bar in a series of products, while advancing the blade of the saw parallel to the trajectory

Description

METHOD AND APPARATUS FOR CUTTING TISSUE OVERPOST The present invention relates to a method and apparatus for cutting overlapping fabrics, and more particularly, to fabrics configured in a multi-layered flat surface elongated ribbon, such as is commonly used as a facial tissue.

BACKGROUND AND SUMMARY OF THE INVENTION The product cut by the invention is usually continuous, and often interfolded, as provided in co-owned US Pat. No. 4,052,048. The example of the apparatus used to cut the batten in stacks is in the United States of America patent in co-owned No. 3,288,009. More generally, during the last 30 years, the primary method for transporting a ribbon through a saw has been with the use of paddle bars mounted on a chain both above and below the bar. At one time, on slow machines, only a lower vane conveyor was used, and the upper part of the slat was stopped with separate plates on each side of the earth's leaves, and traversed with reciprocating saws. A commercial machine that incorporates the previous principle incorporated pallets that were separated to generate openings in a pattern of repetition so that the leaf passed through them, equal to the length of cut that was desired. When other cuts were required, the bars were manually replaced, or the entire chain assembly was replaced. This system has worked well and has not had speed limitations other than the saw. Although this system has worked well for machines whose cutting length is dedicated to a single size for long periods of time, production needs now vary increasingly, and cutting length requirements can often change on a daily basis. The current pallet conveyor requires a minimum of 4 hours to replace the chains in order to achieve a new repetition, and this is generally unacceptable. The object of the present invention is to retain the benefits of cutting with pallets, while obtaining a possibility of fast length adjustment.

SUMMARY OF THE INVENTION The invention for cutting a flat, multi-layered, elongated ribbon of woven material employs the following general steps (and elements therefor): advancing the ribbon along a linear path, rotating a pair of drums mounted in cantilever on the opposite sides of the trajectory, to flank the flat surfaces of the batten, the drums having a plurality of axially extending grooves, equally circumferentially spaced, at their periphery. A saw adjacent to the path is placed in orbit with the orbit of the saw blade that intersects the orbit of the slot to make the cross section of the cleat. Here, the term "ribbon" is used in a broad sense - covering strips by themselves, and also "bundles" of material as they can come out of a rotating interpleter. The cantilever mounting of the drums eliminates any interference with the path of the saw blade. The drums rotate at such a speed that one slot of each drum makes contact with the bar for each step of a sheet. Upstream of the drums there is a series of opposed feeding bands that perform the usual functions of removing the excess air from the strip; mark any folds on the ribbon; control ribbon transport from other upstream equipment; and feeding the appropriate amount of ribbon to the drums for each step of the sheet. As the inward feed bands deliver a fixed amount "X" is trimmed by cutting, the surface of the spinning drums also travels a distance at least equal to, or greater than, this fixed amount "X". This ensures proper feeding of the bar through the contact areas of the drum, without causing a delay of the outer layers. The maximum amount of travel that the drums can exceed "X" per cut, is limited by the width of the groove of the drum, the ratio of the diameter of the drum to the orbit of the blade, and the desired tolerance to stay between the edge of each slot and the face of the sheet. Because the forward speed of the blade must closely match that of the slat, when changing the desired cutting length, the saw head that controls the forward movement of the blades should also be adjusted to match the speed toward forward of the ribbon if a square cut is needed. On saws that orbit at an angle to the forward direction of the lath, forward movement is adjusted by changing the "offset" angle. The examples of these saws are the Patents of the United States of North America Numbers 4,041,813 and 5,289,747; and U.S. Patent Application Serial Number 08 / 223,543 filed April 6, 1994, or the application published in the European Patent Office 555,190. However, the invention can be used with advantage in other orbiting saws such as that of the application published by the European Patent Office 507,750.

In any case, if the length of the cut is equal to the length of the gap between the slots, the sheet stays perfectly centered in the slots. But as the length of the cut decreases (or increases), and the forward speed of the leaves decreases (or increases), the RPM of the drum must remain the same (one groove per cut), and this means that the sheet no longer remains centered in the slot. However, this gives any drum an infinite range of cut - until the tolerance of the slot to the acceptable sheet is lost, that is, previously determined. The commercial pallet chain conveyor that has been used since the beginning of the face saws, gives a fixed length cut of more than 0.0 millimeters (0.0 inches) to less than about 3 millimeters (0.125 inches), depending on how much stress is applied. employ In the invention, and even without varying the previously established tension, the scale is from more than 0.0 centimeters (0.0 inches) to less than approximately 38 millimeters (1.50 inches) - or twelve times more. And this is also possible with the change of length with a press button on the lath conveyor while still retaining the same type of lath support on the cut as the pallet bar system provided. In essence, this new system is an adjustable pallet system, that is, with the ability to change the cutting length quickly and infinitely within a given scale. The "plus" side is zero because if it is larger, then the lath would be traveling faster than the drum - and would be delayed or scraped. The advantages of the method and apparatus of the invention are equally great when an acceptable tolerance of the groove to the sheet with the given drums is no longer present. In such a case, the cutting scale can be changed quickly by replacing the slotted drums. This takes less than 15 minutes compared to 4 hours for the pallet chain design - a factor of 16 times. Other advantages include the ability to fine-tune the length of the cut without adding additional tension to the batten, and the elimination of the use of a chain, which also presents a maintenance and lubrication problem.

BRIEF DESCRIPTION OF THE DRAWING The invention is described in conjunction with an illustrative embodiment in the accompanying drawing, in which: Figure 1 is a fragmentary, side elevation, somewhat schematic, of the apparatus used in the practice of the invention. Figure 2 is a fragmentary sectional view as would be seen along line 2-2 applied to Figure 1. Figure 3 is a schematic side elevational view of a continuous motion saw in accordance with the prior art. Figure 4 is a fragmentary perspective view of a continuous motion saw in accordance with the prior art. Figure 5 is an amplification of the left portion of Figure 1. Figure 6 is an amplification of the central portion of Figure 1. Figure 7 is a schematic elevated view of the central portion of Figure 6. Figure 8 is an amplification of the right portion of Figure 1. Figure 9 is a diagram showing a velocity profile as a function of the cutting cycles. Figure 10 is an amplification of the portion enclosed in a circle in the center of Figure 9.

DETAILED DESCRIPTION Referring first to Figures 1 and 2, the symbol F generally designates a portion of the main frame carrying the lower drum 11. The frame F also carries in a positionable manner an upper frame 12, which in turn carries the upper drum 11 '. More particularly, the upper frame 12 carries in a positionable manner a sub-frame 13, which in turn carries the upper drum 11 '- also seen on a larger scale in Figures 6 and 7. Numeral 14 designates in general the feed conveyor inwards, which is formed from the lower band system 15, and the upper band system 15 * - as seen at a larger scale in Figure 5. The outward feed conveyor is generally designated 16, and is formed from the system of lower band 17 and upper band system 17 '- as seen at a larger scale in Figure 8. Conveniently, all of the upper elements, i.e., the upper feed web system 15', the upper drum 11, and the outfeed belt system 17 ', are mounted on the upper frame 12, so that they can be moved vertically to accommodate different slat thicknesses. Movable mounting of the upper drum 11 'allows it to move or float independently of the upper band systems 15', 17 '. This provides the ability to set the compression levels at the time of separate cutting of the compression in the inward feed bands. It also offers an overload protection o_ of clogging for the drum 11 '. Numerals 18 and 19 (see the central portion of Figures 1 and 6) designate piles of the fabric product, which may be superimposed layers or interfolded layers as in the aforementioned US Pat. No. 4,052,048. The piles 18, 19 are separated by a separation line 20. The stack or product 19 is separated from the batten 21 by another separation line 22. Each separation line 20, 22 has been developed by an orbiting sheet 23 having a wrapper 24 representing the cutting orbit - see Figure 2. In any of the US Pat. No. 4,041,813 or of the other cases mentioned above, a suitable saw can be seen to carry the leaves 23, and the reference to All of these cases are expressly made herein to incorporate their descriptions in this application.

Prior Art Saw Referring now to Figures 3 and 4, the symbol F generally designates the machine frame that includes a pair of side frames. The frame F provides a path P that extends linearly (horizontally) for the transport of the strip R, and finally the separated product R '. The strip R, and subsequently the product R ', are transported along the path P by means of a suitable conveyor generally designated C. The symbol B designates in general the leaf mechanism that optimally includes two disc sheets D - see also Figure 4. As can be seen in Figure 4, a fastener is provided for each sheet as in B, which supports the usual grinders G. The sheets D and its associated structure are carried by a SP phase plate, which supports the phase shift arm A to rotate around a phase shift axis S, which is set at a lower acute angle 0 with path P (see the upper center portion of Figure 4). The rotation of the phase shift arm A is provided by the element M - see Figure 4.

Drums Each of the drums 11, 11 'is cantilevered as can be seen from a configuration of Figure 2, where the drum 11 is seen to include a spider 25 equipped with a plurality of radially extending fasteners. 26. The upper drum 11 'has an identical spider 25' and fasteners 26 '. Adjacent fasteners have separate arcuate flanges 27, 27 'that define slots 28, 28' between them - compare the Figures 1 and 7. Therefore, the rotation of the drums 11, 11 * results in an orbiting of the slots 28, 28 ', corresponding to the periphery or the cylindrical sheath generally designated 29, 29 * in the central portions of Figure 1, and also in Figure 6. As can be seen in FIG. appreciate from a consideration of Figure 2, the envelope 24 of the sheet 23 -intersects to the wraps 29, 29 'of the drums 11, 11', respectively, to provide the cuts 20, 22 by virtue of passing through of the aligned slots 28, 28 '. The fasteners 26, 26 'are secured to their respective spiders 25, 25' by quick disconnect clamps 30, 30 '- see Figure 2. A suitable clamp is Model Number TC-225-U available from Reid Tool, located at Muskegon, MI The drums 11, 11 'are equipped with two grooves such as at 31, 32, and 31', 32 '(see the lower portion of Figure 2), which extend around the periphery and intersect the grooves 28. The grooves 31, 32, 31 'and 32' allow the placement of the separation fingers 33, 33 'in relation to the drums 11, 11' respectively (see the central portion of Figure 7). This helps feed the cutting end of the batten into the feed conveyor belt system 16.

Diagrams of Figures 9 and 10 The cutting action is illustrated graphically in Figure 9, where the ordinate V is the velocity, and the abscissa represents the cutting cycles of the leaf CY, more particularly, the abscissa includes four cycles of cut that would correspond to half a revolution of a drum 11 or 11 'with eight grooves, and two revolutions of a double blade saw. The total length illustrated in Figure 9 is four cycles, as indicated by the dimension line in the lower part of Figure 9. A cutting cycle is designated by the numeral 34 in Figure 9, and the construction line vertical designated as 35, designates itself half of the cut. The numeral 36 designates the coupling of the blade with the groove of the drum, while the numeral 37 designates the horizontal velocity component of a groove of the drum, based on the eight-stroke drum. Numeral 38 designates the speed of the blade of the saw for a nominal cut, while the numeral 39 designates a speed of the blade of the saw for a cut of 38 millimeters (1.50 inches) less than the nominal. The important relationships in Figure 9 are amplified in Figure 10, where again the numeral 35 designates the half of the cut, while the numerals 40 and 41 represent respectively the beginning of the cut and the end of the cut. Again, numerals 38 and 39 respectively designate the speed of the saw blade for a nominal cut, and the speed of the saw blade for a cut of 38 millimeters (1.50 inches) below normal.

Still referring to Figures 10, the other designated portions include 42, which represents the blade speed at the beginning of the cut for a minimum cutting length, while 43 designates the blade speed at the beginning of the cut for a length of nominal cut. The numerals 44, 45 designate the speed of the groove at the beginning and end of the cut, for any length of cut in the available range with a given geometry. The diameter of the drum causes an almost constant speed during the coupling of the blade-groove, due to its large diameter. The movement is slightly greater than the constant speed, because it curves like the movement of the blade. Below the blade speed of the saw 39, half the tolerance of the blade-slot is lost, unless an extra slot is added, at which time the drum speed is also decreased, bringing it closer to the drum. leaf speed.

Operation The outboard feed belt systems 17, 17 'provide control for the front end of the newly formed stack during cutting, and also control and transport it away for other handling. This band system is optimally operated at a speed equal to, or exceeding, the surface speed of the drums 11, 11 '. As noted above, as the length of the cut decreases / increases, and the forward speed of the saw also decreases / increases, but the speed of the drum remains the same (one slot per cut), the sheet already it does not focus on the groove, and when the acceptable tolerance of the groove to the blade is lost, the drum has to be exchanged with one that has either more or less grooves - assuming there are no changes in drum diameter . This will then cause a change in the drum RPM, reducing the mis-coupling of the forward speed. Based on a saw blade that makes an arc of a radius of 600 millimeters (24 inches) and a drum that has just a radius of 300 millimeters (12 inches), the initial tolerance of the blade to the groove is reduced by half after a cut adjustment of 38 millimeters (1.50 inches) below the nominal cutting length of the drums. It would be the same if one were 38 millimeters (1.50 inches) above the nominal, but, as discussed above, the system would work better if the nominal cut length were not exceeded. An example of a suitable configuration is a slot width of 25 millimeters (1 inch) with a scale of variation width of the position of the sheet up to approximately 13 millimeters (0.50 inches) going out of a tolerance (if the sheet is centered as in nominal cut) of 6 millimeters (0.25 inches) on each side. In order to cut a section of 12.5 millimeters x 12.5 millimeters (5 inches x 5 inches), it is convenient to use a saw that has a radius of 610 millimeters (24 inches) to the center of the blade - 914 millimeters (36 inches) up to the wrap, and a drum that has a diameter of 610 millimeters (24 inches). Normally, the speed of the conveyor is limited by the speed of the saw. The main reason why the blade remains centered in the groove during a nominal cut is due to the fact that the large diameter of the drum causes an almost constant speed during the cutting phase. However, the movement is actually better than the constant speed, because the slot accelerates horizontally before cutting, and slows down afterwards - just like the blade. This is due to the fact that both the groove and the sheet are simultaneously drawing sinusoidal arcs, although in different planes of intersection. The blade, as always in the two-bladed saws, with respect to the slat, accelerates to the point of the middle cut, and then decelerates as it leaves the slat, until all the forward speed stops in half a cycle after of the medium cut. Any groove in the drum also accelerates with respect to the cleat as it approaches the contact with the cleat and until the middle cut, at which time it slows down due to its rotating travel. The difference is that half a cycle after the medium cut, the groove does not stop, but continues to decelerate. Due to practical size reasons, the drum will usually have 6 to 14 slots around, while the saw has two blades. The openings or slots in the drums are sized to provide the same degree of support to the bottom of the slat, as with the chain conveyors, with the lower slot being more critical, since it prevents the lower layers from tearing - which was a previous problem. The upper drum can have more tolerance of the groove, since its main job is to provide the feeding of the batten, and the compression on the batten, so as not to allow the cutting action to alter the appearance of the batten.

Thickness and Compression Adjustment As noted above, the upper frame 12 can be raised or lowered to adjust to different slat thicknesses. This is effected in the illustration given by the provision of vertically elongated screw elements 46, 47 - see Figures 1 and 2. These are received in the jack elements 48, 49 fixed to the upper frame 12, and the screw elements 46, 47 are attached to the main frame F. For simplicity, the power elements for the jack elements 48, 49 are illustrated by the manual wheel 50, the jack elements 48, 49 coupling with each other by an arrow 51. For guiding the movement of the upper frame 12 during vertical movement, slider and rail elements generally designated at 52 are provided - see the upper right and left portions of Figure 1. The two elements 52 are the same, so that only the right configuration. The rail 55 is mounted on a transversely extending reinforcing portion Fa of the main frame F. This can be better appreciated from a consideration of Figure 2, where the main frame F is seen as a plate-like member. extending longitudinally, equipped with a transversely extending reinforcement or flange Fa that extends upwardly from the base plate Fb. This reinforcement extends upwards to the cat element 46, which it supports, as well as to the rail 55. The sliders 53, 54 fixed to the upper frame 12, are slidably received by the rail 55. Previously, mention was also made of the mobility independent of subframe 13, which carries the upper drum 11 '. The subframe 13 is fixedly equipped with two vertically aligned top sliders 56, and a slider 57 longitudinally spaced therefrom (see Figure 1), also being designated the top of the sliders 56 in Figure 2. The sliders 56 slidably receive the rail 58, while the slider 57 receives the rail 59. The rails 58, 59 are fixed to the upper frame 12. The adjustment of the position of the subframe 13 is achieved by a stop screw 60 (see Figure 6) received threadedly in the upper frame 12, and that determines how low the subframe can move under its own weight. The "floating" nature of the subframe 13, and consequently, of the upper drum 11 ', provides the clogging ratio.

Drum thrust The lower drum 11 is equipped with an inlet pulley 61 - see the lower right part of Figure 2. This is removably mounted on the arrow 62, which carries the spider 25. Arrow 62 also bears an impulse pulley 63, which engages the driven pulley 63 'carried by the arrow 62' of the upper drum 11 '. The coupling is by a corrugated strip 64, which ensures that the drums 11, 11' are rotated synchronously . Referring now to Figure 1, the numeral 61 designates again the input pulley for the drum 11.

This receives power through the band 64 from the impulse pulley 65. This could be representative of the 13-beat drum. However, when the drum 11 has a different number of grooves, a different input pulley is used - as in 66 -, and the band 67 which could correspond to an 8-stroke drum. Different tension pulleys are used as in 68 and 69 for the different band configurations 64, 67. The power for the pulley 65 is derived from an arrow 70, which is interconnected with the arrow of the main line L by means of of line 71, and a variable speed pulse VS - see the lower left portion of Figure 1. This provides the pulse generally designated at 72 for the outward feed conveyor 16, which, together with the pulse for the saw and the drums, which provides a speed different from the feed speed of the feed conveyor inwards.

Impulse for the Outward Feed Conveyor The impulse for the outward feed conveyor 16 also comes from the arrow 70 in the lower right part of Figure 1, and is seen on a larger scale in Figure 8. For that purpose, the arrow 70 carries a pulley 73, which, by means of the web 74 and the tensioning pulley 75, drives the pulley 76. The pulley 76 is fixed on the impulse shaft of the conveyor or shaft 77, which also carries the roller impulse 78 on which the conveyor belt 17 is inserted.

The band 17 is wrapped about 180 ° from the roller 78 as seen in the right center portion of Figure 8, and passes around the roller 79. The band 17 has an upper slider which runs downstream between the front roller 80 and the rear roller 81. All the pulleys and rollers of the belt are carried by the frame F, and the details of the assembly have been omitted for greater ease and clarity of the presentation. An example of the assembly of an element can be seen in Figure 2, where the bearing for the arrow 62 carrying the lower drum 11, is secured to the frame F. In a similar manner, the different pulleys and band rollers for the upper outward feed conveyor 17 ', are carried by the upper frame 12. The pulse for the upper outward feed conveyor 17', includes a pulse pulley 82 on which the web 83 is inserted. The pulley 82 is coaxial with the front roller 78 on the shaft 77. As seen in the right portion of Figure 8, the band 83 that is traveling upwardly away from the pulley 82, gets onto the pulley 84. The pulley 84 is rotatably mounted on a flange 85 fixed to the reinforcement of the main frame Fa. The band 83 is then wrapped around the pulley 86, which is coaxial with the front roller 78 'for the upper conveyor 17'. This roller is carried by the shaft 77 'supported on the upper frame 12. The band 83 then goes around the pulley 87, also mounted on the upper frame 12 - before traversing back to the impulse pulley 82. The group of three pulleys 84, 86 and 87, ensures that the travel of the band remains constant, regardless of the position of the upper frame 12. In other words, the distance of the band in the path from the pulley 84 to the pulley 82 remains constant. The pulley 87 is grooved to provide an element for initially tensioning the band 83. The bands 17, 17 'are suitably tensioned by the mechanisms 88, 88' provided respectively on the main frame F and the upper frame 12. It is convenient to configure the a divergent nature - when proceeding downstream - of the bands 17, 17 '. This releases the compression on the products 18, 19, et cetera, which was provided by the drums 11, 11 '. As illustrated, the lower slider of the upper band 17 'has a slight upward inclination developed by the roller 89.

Impulse for the Inward Feed Conveyor Referring to Figures 1 and 5, numeral 90 in the lower left portion represents a transmission box that connects to the line arrow L. Referring now to Figure 5, the output of the transmission case 90 is provided by a pulley 91, which is coupled with an impulse pulley 92 by the web 93. The pulley 92 is mounted on an arrow 94, which also carries a pulley 95 coaxially with the pulley 92. The pulley 95 in turn inserts a band 96, which runs around a group of three pulleys generally designated as 97, to accommodate the vertical movement of the upper frame 12 without changing the length of the band travel. Accordingly, as was the case with the feed conveyor group out of the pulleys 84, 86, and 87, the group 97 provides a pulley 98 fixed to the main frame Fa, and the pulleys 99 and 95 'mounted on the upper frame vertically movable 12. The pulley 95 'is mounted on an arrow 94', which also carries a driving roller 100 'coaxially with the pulley 95'. The band 101 'of the upper feed conveyor 15' wraps the roller 100 ', proceeds through a tensioning device 102', then around the rear roller 103 ', and eventually around the front roller 104'. The lower inward feed belt system 15 provides a similar band 101 having an upper slider that proceeds from the rear roller 103 to the front roller 104, then around the roller 100 which is also mounted on the arrow 94, then through of the tensioning device 102, and finally back to the rear roller 103.

Compression Control Still referring to Figure 5, the numeral 105 generally designates a load cell that develops a constant compression on the batten 21. A suitable device is a Model 41 available from Sensotec, located in Columbus, Ohio. The load cell 105 is mounted on the upper frame 12, and engages with the arm 106, which is pivotally mounted on the upper frame 12, and which carries three of the rollers that rest against the lower slider of the belt. upper inward feed 101 - still referring to the central portion of Figure 5. When the load cell 105 detects a change in thickness, an appropriate signal is sent to the PLC controller of Figure 3, which drives the element to raise or lower the subframe 12. This can be a stepping motor as mentioned above, and a suitable motor is the Model SS700, available at Superior Electric located in Bristol, Connecticut. The use of charge cell feedback stabilizes the amount of slat fed in each cycle, because constant compression of the slat is maintained as slat density changes. The overall control of the operation is provided by a programmable logic controller of the type normally associated with continuous-motion saws. A suitable driver is from the Allen-Bradley 5 PLC Series located in Milwaukee, Wisconsin. As indicated above, the PLC is shown in Figure 3 as part of the prior art, but in addition to regulating the operation of the saw, it is also used herein to control the operation of the variable speed pulse VS, which in this way it also controls the impulse of the feed conveyor outward generally designated at 72, and the speed of the drums 11, 11 '. The PLC can also control the L line arrow, and with it, the advance of the lath 21 from the unwinders (not shown) to the inward feed pulse system generally designated at 107 - see Figure 1. A control is included or additional function, and for this, reference is made to Figure 6. There it will be noted that each fastener 26, 26 'is equipped with an opening 108 or 108'. These are used when a replacement drum is installed. Because it is not known exactly where the spider 25, 25 'stops, I have discovered that it is convenient to place a number of alignment slots 108, 108' around each drum. An alignment hole is provided in the main frame F and in the upper frame 12, so that a rod can be conveniently inserted through the holes of the frames (not shown), and of the alignment openings 108, 108 ' Operation Summary The method of the invention for cutting an elongated, multi-layered, flat surface slat of fabric material 21 (see the center portion of Figure 1) includes the steps of advancing the slat along a trajectory linear P, rotate a pair of cantilevered drums 11, 11 'on opposite sides of the path to flank the upper and lower flat surfaces of the batten, the drums having a plurality of axially extending slots 28, 28' in the orbiting periphery thereof, orbiting a saw blade 23 adjacent to the path, and cyclically intersecting the orbit of the blade 24 with the orbits of the slots or shells 29, 29 'to crosscut the ribbon as in 22, in a series of products 18, 19, while advancing the blade of the saw parallel to the trajectory. Correspondingly / the apparatus of the invention for cutting a multi-layered elongated ribbon having upper and lower flat surfaces, includes a main frame F defining the linear path P. There are elements 14 on the frame to advance the lath 21 to along the linear path. Later, in the path a pair of cantilevered drums 11, 11 ', mounted on the frame, on opposite sides of the path, are provided to flank the flat surfaces of the lath. Each of the identical drums has a plurality of axially extending grooves 28, 28 'at their periphery 29. The elements as in 61-70 are operatively associated with the frame for rotating the drums, to orbit the grooves as in 29, 29 '. A saw blade 23 is mounted on the frame adjacent to the path, and elements such as in M in Figure 4 are operatively associated with the frame to orbit the blade in 24. The orbits of the drum and blade 29, 29 ', 24, intersect cyclically in the path P to cut transversely at 20, 22 the lath, in a series of products 18, 19, while advancing the sheet parallel to the path. The drums 11, 11 'are rotated by the drive element 61 at a surface speed at or greater than the forward speed of the lath 21. When a change in the length of the product 18, 19 is desired, the speed of the lath is changed in relation to the speed of the drum. For example, when 500 products per minute are desired, but the length has to be increased, the main impulse L is "streamlined in such a way that more ribbon is passed through the saw. However, then variable speed control VS will slow down the forward speed of saw 23 to retain 500 cuts per minute. Then, if you want a square cut, you have to change the phase angle. - In the illustration given - with a range of 38 millimeters (1.50 inches) - if you want to go beyond that range by changing the length of the product , then the drums 11, 11 'have to be changed. Normally, this involves replacing the drums with those that have a different number of slots. An alternative is to provide drums having a diameter and a circumferential dimension of different grooves. Optimal operating conditions include orienting the saw blade offset to provide a velocity component parallel to the path having a sinusoidal profile, and orienting the drums to provide a velocity component parallel to the path that also has a sinusoidal component , and with the maximum of both sinusoidal profiles generally coinciding, whereby the orbit intersections are generally half way along the circumferential length of each slot. The preferred form of the invention includes providing the inward feed and outfeed conveyor elements 14, 16 in the path P on the upstream and downstream sides of the path, each conveyor member having upper and lower band slides 15. , 17, 15 ', 17', and mounting the upper slides 15 ', 17', and the upper drum 11 'between them, for movement towards and away from the slat 21, to accommodate the slats of different dimensions between their surfaces flat and / or to provide different ribbon compressions. The preferred form further includes providing an assembly 13 for the upper drum 11 'to move independently of the upper slides 15', 17 'of the conveyor element, to establish compression loads separate from those of the inwardly feeding conveyor 14. In the Given illustration, the upper frame 12 carries in a positionable way a sub-frame 13, which in turn carries the upper drum 11 '. The arrow 62 'for the spider 25' extends through the frame 12 (see Figure 2), in such a way that, to accommodate this movement, the frame 12 is equipped with an off-round opening 109 - see top of Figure 6. The invention further includes providing a sensing and signaling element of the dimension or compression of the batten 105, operably associated with the inward feed conveyor element 14, and move all conveyor elements 15, 11, 17 'through the frame 12 in response to a signal from the sensing and signaling element 105.

Although a detailed description of an embodiment of the invention has been established in the above specification for purposes of illustration, those skilled in the art can make many variations in the details given herein, without departing from the spirit and scope of the invention.

Claims (22)

1. A method for cutting an elongated, multi-layered flat surface strip of weaving material, which comprises the steps of: advancing the lath along a linear path at an advancing speed; rotating a pair of cantilevered drums on opposite sides of the trajectory, to flank the flat surfaces of the lath, each of the drums having a periphery and a plurality of grooves extending axially at its periphery, defining these grooves, when the drums are rotated, orbits of grooves; orbiting a saw blade adjacent to the path, and cyclically intersecting the orbit of the blade with the orbits of the slots, to crosscut the bar in a series of products, while advancing the blade of the saw parallel to the path. The method of claim 1, wherein the method includes rotating the drums at a surface velocity equal to or greater than the forward speed of the lath. The method of claim 1, wherein the method includes changing at least the forward speed of the ribbon to provide a change in the length of the product. The method of claim 3, wherein the method includes providing the saw blade with a feed rate, and changing the feed rate of the saw blade during cutting. The method of claim 1, which method includes: (a) changing the forward speed of the lath, (b) providing the saw blade with a forward speed, (c) changing the forward speed of the lath the saw during the cut, and (c) replace the drums to provide a change in the length of the product. The method of claim 5, wherein the step of replacing includes providing first drums with a first number of grooves, and subsequently replacing the first drums with the second drums having a different number of grooves. The method of claim 5, wherein the step of replacing the first drum includes replacing the first drums with the second drums having a diameter and a circumferential dimension of the different grooves. The method of claim 5, which method includes providing the drums with a surface speed, and changing the surface speed of the drum, as well as changing the drums. The method of claim 1, which method includes orbiting the saw blade at a phase angle. The method of claim 9, which method includes changing: (a) the speed of advance of the lath, and (b) the angle of lag of the blade of the saw, to provide a change in the length of the product. The method of claim 10, which method includes providing the grooves of the drum of a previously determined circumferential dimension, and when the change in the offset angle still provides a tolerance of the blade to the previously determined groove, retaining the drums in its position, but when the change in the phase angle provides less than the tolerance of the blade to the previously determined slot, replace the drums. The method of claim 1, the method of which includes orienting the phase shift of the saw blade to provide a velocity component parallel to the path, having a sinusoidal profile, and orienting the drums to provide a velocity component parallel to the trajectory, which also has a sinusoidal component, and the maximum of both profiles is generally coincident, whereby the cyclic intersections of the orbits are generally halfway along the circumferential length of each slot. The method of claim 1, which method includes providing feed-in-feed and feed-out elements in the path on the upstream and downstream sides of the patheach carrier element having upper and lower band slides, and mounting the upper slides and the upper drum to move towards and away from the slat, to accommodate slats of different dimensions between the flat surfaces and / or to provide different ribbon compressions. The method of claim 13, which method includes providing an assembly for the upper drum, to move independently of the upper slides of the conveyor element, to establish compression loads separate from those of the feed conveyor inwardly. The method of claim 13, which method includes providing a sensing and signaling element of the bar dimension operably associated with the feed conveyor member inwardly, and moving the upper slider of the feed conveyor inward in response to a signal from this element of detection and signaling. The method of claim 13, which method includes providing a slat compression detection and signaling element, operably associated with the feed conveyor element inwardly, and moving the upper slider of the feed conveyor inwardly in response to a signal from this detection and signaling element. 17. An apparatus for cutting a multi-layered flat surface elongated ribbon of a woven material, which comprises a frame defining a linear path, an element on the frame for advancing the ribbon along the linear path , a pair of cantilevered drums, mounted on the frame on opposite sides of the path, to flank the flat surfaces of the lath, and having axes of rotation, each of the drums also having a periphery and a plurality of grooves which extend axially at that periphery, an element operably associated with the frame for rotating the drums, for moving the grooves through the orbits, a saw blade mounted on the frame adjacent to the path, and an element operably associated with the frame to orbit the sheet, intersecting the orbits of the drum and the sheet cyclically to the path to crosscut the bar in a series of products , while advancing the sheet parallel to the trajectory. 18. The apparatus of claim 17, which apparatus includes an element for changing the rotation speed of the drums. 19. The apparatus of claim 17, which apparatus includes an element for changing the forward speed of the lath. 20. The apparatus of claim 19, which apparatus also includes an element for changing the advance speed of the saw blade. The apparatus of claim 17, wherein the drums are equipped with elements for removably mounting them on the frame. 2

2. The apparatus of claim 17, wherein elements are mounted on the drum to advance the cut product away from the saw blade, including these advancing elements of the upper and lower band systems, which have slides that make contact with the products, diverging these sliders in the direction of advance of the strip to release the compression in the products, provided by the drums.