US 2769495 A
Description (OCR text may contain errors)
1956 A. w. POMPER ET AL 2,769,495
WEB CUTTING AND SHEET DELIVERY AND STACKING MECHANISM Filed July 1, 1953 J/ v I ETTORNEYS United States Patent WEB CUTTING AND SmET DELIVERY AND STACKING MECHANISM Anthony W. Pamper, Piscataway Township, Middlesex County, and Charles J. Waechter, New Market, N. 3., assignors to John Waldron Corporation, New Brunswick, N. J a corporation of New Jersey Application July 1, 1953, Serial No. 365,376
6 Claims. (Cl. 164-68) This invention relates to improvements in web cutting and sheet delivery and stacking mechanism primarily intended for but not limited. to use as an integral part of a high speed, multicolor, oiiset printing press.
It is a generalobject of the present invention to provide a novel and improved mechanism for cutting a rapidly moving web into sheets, delivering and stacking the sheets, the apparatus being adaptable for use with a wide range and gauge of materials.
More particularly it is an object of the present invention to provide in a mechanism of the type described cooperating stationary and moving cutters arranged to receive a continuously travelling horizontal web, a set of pull rolls to engage the leading end of the web when it is being cut and a solid plate to carry the advancing web between the cutters and the pull rolls, the plate be ing contoured to clear the travelling cutter.
A further object of the present invention consists in the provision of air blasts adapted to hold down the corners of the advancing web end as it approaches the pull rolls.
A still further object of the invention comprises the arrangement of controlled air blasts to wipe down each cut sheet onto the pile on the dropboard or platform in time to clear its trailing end from the path of the leading edge of the succeeding one.
An important object of the invention comprises. the use in association with a sheet stacking mechanism of sheet delivery means including high speed horizontal sheet discharge means and apparatus for successively and progressively blasting down the sheet onto the stack beginning with its rear edge as it leaves the discharge means.
As a feature of the invention may be noted the use of cams driven in timed relation to the cutters for the control of the various air jetsfor handling and positioning the web and sheets.
Other and further objects and features of the invention will be more apparent to those skilled in the art upon a consideration of the accompanying drawing and following specification wherein is disclosed a single exemplary embodiment of the invention, with the understanding that such changes and modifications may be made therein as fall within the scope of the appended claims without departing from the spirit of the invention.
In said drawings:
Fig. l is a schematic and diagrammatic side illustration of apparatus constructed in accordance with the present invention; and
Fig. 2 is an enlarged top plan view and partial section thereof taken on line 2-2 of Fig. 1 illustrating the arrangement of the grid of guide wires and air jet pipes.
The operation of cutting web material into sheets and stacking the same has always been fraught with difiiculties and as the speed of delivery of the web increases and the thickness of the material decreases the problems multiply many fold. The cutting and stacking of sheets is carried out. under various conditions. In converting r 2,769,495 C6 I Patented Nov. 6 1 5 roll paper to sheets for use as stationery there occurs not only the difiiculty of transverse cutoff but also horizontal severing, which complicates the stacking problem. Where material is treated as by coating, laminating, embossing, printing or the like, the operations are materially simplified when done on the travelling web. Economic conditions require that these operations be carried out at hi h speeds and machinery for these various conversions has been improved to the point where the speed of conversion has become too high for direct feed to the known types of cutting, delivering and stacking devices,
I particularly where thin materials, such as light weight paper and the like, are involved. Where speeds of the order of four or five feet per second are achieved, great difiiculty is experienced in preventing the sheet material after cutting, or the leading free edge of the succeeding web, as it is being fed forward, from fluttering, folding,
twisting and bending in such a manner that successive sheets interfere with each other and the stacking operation becomes impossible.
The present invention is directed to a mechanism for cutting the full width of a web of any reasonable thickness into successive sheets and stacking them in deep vertical piles after printing on the web, but obviously the invention is wholly independent of the initial treat: ment of the web material and no treating mechanism has been shown in the drawings.
In those drawings, and particularly in Fig. 1, the web 10 is shown approaching from the left under the draft of a driven pull roll 11. Tension is maintained by means of spring pressed wheels 12 of any desired number resting on top of the web as it passes over the pull roll. Added traction may be provided by increasing the angle of com tact. Immediately on leaving the nip of the roll and wheels the web is supported on and passes over the horizontal plate 14 of solid metal. This plate terminates at 15 closely adjacent to and in the horizontal level of the cutting edge of stationary ledger blade 16 itself eX- tending at least the full width of the sheet and normal to its axis of movement.
Cutting is achieved by a rotary blade 17 cooperating with the ledger blade. Its edge travels as an element in the surface of an imaginary cylinder depicted by the arrow 18 and as tangential to the edge 16. Blade 17 is mounted on drum 19 which drives the cutting edge thereof at a linear velocity slightly greater than that of the pull roll 11 so as to clear the advancing edge of the web after cutting. The blade is counterbalanced by weight 20 on the opposite side of the drum 19 to inhibit vibration.
At a distance beyond the edge of the ledger blade 16 less than the length of a sheet which the machineis designed to cut is a second driven pull roll 22, and a nip for pulling the web is achieved by a plurality of spring pressed, spaced apart discs or wheels 23 bearing thereon. In many circumstances only the edge wheels are necessary both at 23 and at 12.
At the time of cutting at the junction of 16 and 17, which occurs while the web is gripped fore and aft, the leading edge of the web, now a sheet, is some distance to the right of the pull wheel 22, and this cut sheet is fed to the right by roll 22 and its trailing edge is immediately followed, under the action of roll 11, by the leading edge of the web which has just been severed. The roll 22 is driven at a slightly greater peripheral speed than roll 11 so as to provide a slight separation between the trailing edge of the sheet and the leading edge of the web. This latter edge arrives at the drive roll 22, which tightens the web, prior to the next cutting operation so that cutting is achieved while the paper is held adjacent the leading edge of the forward part and behind "the cutter. l
ward movement and has often given trouble under the aetionofeir currents-stirred up by rotating paits'of the apparatus and for otherreasons, but inaccordance "with the present invention these difficulties are wholly elim Qin'ated by the presence of the continuous unperfor'ated contour plate-25 extending from a' position '26 as close 'aspossible to thecutting edges a't'their mating position to the position 2 7 closely adjacent the nip of 'the'roll 22 and wheels 23. This plate is wider than the web and" extends horizontally rearwardly from a position 27 toward the positio'n 2'6, 'the'nip of'th'e second set of pull rolls, however, being lower thanthe mating 'p'osition of the cutters. The cutting preferably takes place'at about 45? in adi'an'celof the bottom center of bla'de'rotat'ioh. The "plate is substantially tangentially to but slightly below the path of the'ed'ge-of cutter 17 at the position 28'directly below the center 29*of'the Cutting drum and from here rearwardly is curved upwardly to the-position 26 following an are parallel to and of only slightly greaterradius than that of the cuttingedgeofthe blade This contour 'plate entirelypr'otects the leading edge of'the web'p'rojectedforwardly' by the feedroll 11 from the cutters as well a'sthe trailing end of the recently transversely of the direction of web'traveland supported substantially as shown by the arrows.
cut sheet being drawn'toward the pull roll -22 so that 7 they 'move smoothly and unperturbed by air currents or other disturbing factors. The'leading edge is thereby fed to theroll-wheel combination 22, '23- exactly trans- .vers'eto the line of-travel and there is "no twisting 'of thepaperto disturb the alignment of the "subsequently built stack about to be described.
'Cooperating'with the contour plate 25 adjacent its intermediate position to insure against lifting of the leading edge "are the front ends 30 of a'plur'ality of guide wires or rods which extend from positions just adjacent,
theblade edgetravel cylinder- 18'entirely across the top of the sheets on the stack. These rods are supported in any suitable manner, not shown,to have throughout their'str'aight lengths 31 above the stack a'slight downa ward incline as shown. -However beginning at a position just above the rear edge 27 of the contour plate these wires curve gently upward to'the rear as clearly seen in Fig. '1 'to insure engulfing the leading edge of the web as "itfapproaches the pull roll 22. border to clear the ni'p'of theroll and wheels these wires pass each between apairi of the wheels 23, as clearly seen in Fig. -2 which are spaced for, comfortable clearance ,of the rods. These rods are in the nature of safety devices and prevent the sheet under any circumstances from 'beingblown or otherwise liftedaway from the'stack or the leading edge of the web from the nip of the roll.
The' cut sheet ;fedby r0ll 22 -adva'n ces over a horizontal drop board 33 of conventional form, which is constructed to move slowly'downwardly at. the-same rate at which the sheets stack above it. drop 'board are mounted the r'ear guides 34, the front stops 35 and appropriate side guides, not shown, to insure a straight pile. The structure "and operation of this 'drop board form no part of the present invention, it'beingonly required that'it keep the top edge of the Adjacent the lower it so that the once integralportions, now separate and opposing edges, may not tangle to cause puckering and folding of the paper so as to prevent proper piling.
To insure rapid lowering of each cut sheet, progressive air blasts are directed against its upper surface as it floats above the pile, and'these are projected from nozzles in aLpIUralit'y of pipes-or tubes.3f 7 extending above the rods, as seen'in Figs. .1 and 2. A' substantial number, eight "as shown, ofthe'se tubes 'isilprovideda-nd each has a number of nozzles 38 directing airstreams Compressed air under suitable pressure :is; provided from manifold 38 "ahd delivere'd' to theseveral tubes 37 by means of hose-sections 39 eaeh under' the control of a valve 40 connected by a shortlength of pipe to manifold 38. These valves are each manipulated by means of a earn '41 mounted on shaft 42-rotated in proper phase and speed in relation to the sheet cutting mechanism. These cams are so adjusted, contoured and timed that a the jets of air from thetube 37nearest to'thewheels23 strikethe sheet just before it is released fromthe nipof the wheel-roll combination. These jets are directed slightly rearwardly as shown by' the arrows.
At this time-the remaining jets areinoperative but they are progressively and successively activated toward r the 'air to escape. e
stackat the proper level somewhere around the height'of the axis of the pull'roll '22. V
The rate-at'which theweb travels'u'nd'er the operation of the pull rolls' shoots theleading edge "forward over the'pile' on the drop' board supported on a cushion of air. In fact it might almost be said that the sheet at its high velocity is air borne,at least its forward portion. It cannot rise'to any great extent because of the hold down action of I therods 31, but when it reaches thefrbnt stops 35, which terminate its movement, it tends to floaton 'its air cushion too long' to clear the way for the advancing edge of the web about to be cut into the next sheet. Means are therefore providedto Thejets are so timedin relation to the speed of the sheets that the air used to blow down any sheet as dc seribedabove'thenserves-to float the following sheet toward the rear stops. The leading edge of the following sheet is alwaysrjust'behind the elevated portion of the wave of the preceding sheet and the rebounding or turbulent air from the then active "jet pipe -flows beneath the edge to keep thesheet elevated.
When a delivered sheet is viewedunder a" stroboscopic light system a wave is" seen to travel along the paper starting from its rear edge-and moving toward its forward end, which shows it to be progressively laid down against the preceding sheet on the pile, wiping the air toward the right and out through the stops. The principalpurpose; of course, is to lower the rear edge im-- mediately out of the path of the approaching leading edge of. the succeeding sheet, and practical operation proves the effectiveness of the arrangement. a
One additional refinement'has been found'helpful, and
that comprises two jets from a further pipe or tube- 45' positioned to be directed onto the-leading corners "of the web as it approaches the nip of the roll22. This pipe under the action of 'its valve'46 and cam-47 directs the V 7 jets, one at each corner, somewhat at the angle shown by the arrows. The'cam is preferably timed to release the blasts after the paper is inposition beneath the nozzles, although experiments have shown that continuous operation of these jets does 'not interfere with the action of the mechanism. These blasts overcome any tendency of. the leading corners of the approaching web to turn inwardly.
They have a normal tendency to curl, resulting from their 7 recent cutting and 'from'the lifting action of the air getting beneath them. These blasts positively insure against their being folded back in the nip of the rolls. a
The Whole assembly just described has. proven most effective in the handling of webs of various weights an'd materials and successfully cuts them into uniform sheets formed into a neat pile even when the web speed :is as high as seven feet per second.
We claim; 1. -In-mechanism of the type described, in combination,
a ledgerplate, a rotatable cylinder having a knife blade projecting therefrom to cooperate with said ledger plate when substantially midway between the horizontal and bottom positions, means to deliver a web horizontally over said ledger plate, pull rolls spaced from the ledger plate a distance less than the length of a cut sheet, an imperforate metal plate fixed and extending from the edge of the ledger plate to a position just in advance of the nip of said rolls, said metal plate being curved to parallel the knife movement from the ledger plate to a position directly below the cylinder axis and horizontal from there to the said position adjacent said nip.
2. The mechanism of claim 1 in which means is provided to direct a downwardly and forwardly inclined and sharply defined jet of air against the upper face of each leading corner of the advancing web only as it leaves the forward edge of said metal plate for entrance into the roll nip.
3. The mechanism of claim 1 in which the upper of the pull rolls is divided into longitudinally spaced discs, stationary guide wires extending through the spaces between discs, flaring upward over said plate and inclining down- Wardly beyond the rolls and an automatically lowering pile receiving platform beneath said wires beyond the rolls.
4. The mechanism as defined in claim 3 in which a plurality of transverse pipes are spaced above the pile platform throughout its length in the direction of sheet advance, a plurality of jet nozzles in each pipe directed toward the platform and means timed to the operation of the rotary knife to successively individually connect the pipes beginning with the one nearest the pull rolls to a source of air under pressure each time a sheet is advanced to a position fully above the pile on the platform.
5. Apparatus for cutting a high speed travelling web into sheets, comprising in combination, means including a roll nip for continuously feeding said web horizontally, a travelling knife having an edge forming an element of a horizontal cylinder and rotatable about the axis of said cylinder, a stationary blade positioned to have the web pass over its edge and to cooperate with said travelling knife prior to the latter reaching its lowest position on the cylinder, a solid plate extending substantially from said nip to said stationary blade to support the web, means to drive the travelling knife edge at a linear speed substantially the same as that of the web, a driven pull roll and spaced cooperating wheels resting thereon to provide a second nip less than the length of a sheet from the stationary blade, a drop board beyond said rolls, a continuous plate extending from the stationary blade to the second nip adapted to support the Web out of the path of said knife before and after cutting and having its leading edge below the trailing edge of the solid plate, rigid wires having their forward ends above said continuous plate just clear of the knife path, said wires sloping downwardly toward but above said second nip, passing through the spaces between said wheels and extending downwardly over said drop board, stops for the cut sheets adjacent the opposite ends of said wires, and means to deliver a jet of air down against each leading corner of the cut web end as it approaches the second nip.
6. A contour plate for delivering the leading end of a travelling web adapted for severing into sheets between a cutter of the rotary cylindrical path and ledger blade type and the nip of driven pull rolls spaced less than a sheet length therefrom comprising a continuous transversely flat sheet at least as wide as the paper web extending substantially horizontally from its terminal edge closely adjacent to said nip to a position slightly below the point of intersection of the path of the movable cutter and its vertical radius and then extending arcuately and parallel to the cutter path and only slightly spaced therefrom to its forward edge substantially at and below the cutting edge of the ledger blade, and stationary guide wires converging from positions near the blade path and well above said plate toward said terminal edge.
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