US 3784186 A
An elongated continuously traveling web is longitudinally pleated, transversely folded and subsequently severed to provide pleated and folded articles therefrom. The traveling web is first bowed into a substantially concave transverse cross section and then is pleated by forcing portions of the web to move outwardly in a direction normal to the direction of web travel. The pleats are formed along lines extending radially from the bowed cross section and the pleats converge at a focal point at which the pleats are forced together to form a longitudinally pleated web. Next, the pleated web is transversely folded in a zigzag manner and is severed to form a longitudinally pleated and transversely folded article.
Description (OCR text may contain errors)
llnited States Patent [1 1 Lenthall et al.
[ METHOD OF AND APPARATUS FOR MAKING PLEATED AND FOLDED ARTICLES FROM A WEB  Assignee: International Paper Company, New
 Filed: June 24, 1971  Appl. No.: 156,184
692,101 7/1965 Italy 270/73 Primary ExaminerRobert W. Michell Attorney-Fitch, Even, Tabin & Luedeka  ABSTRACT An elongated continuously traveling web is longitudinally pleated, transversely folded and subsequently severed to provide pleated and folded articles therefrom. The traveling web is first bowed into a substantially concave transverse cross section and then is pleated by forcing portions of the web to move outwardly in a direction normal to the direction of web travel. The pleats are formed along lines extending radially from the bowed cross section and the pleats converge at a focal point at which the pleats are forced together to form a longitudinally pleated web. Next, the pleated web is transversely folded in a zigzag manner and is severed to form a longitudinally pleated and transversely folded article.
6 Claims, 9 Drawing Figures PATENTEDJAN 81974 SHEET 2 BF 6 PAINTED- W4 3,784,186
- sum 3 UF 6 YPMENTEDJAN 819M 3.784.186
SHEU 5 [IF 6 METHOD OF AND APPARATUS FOR MAKING PLEATED AND FOLDED ARTICLES FROM A WEB This invention relates to an apparatus for and a method of pleating and folding elongated webs and forming therefrom compact, pleated and folded articles.
Various webs of materials such as plastics, paper, nonwoven fabrics or textile fabrics are formed in long, continuous webs which are relatively wide and continuous in length. Large articles formed from these materials, such as bed sheets, blankets, protective shields, etc., are usually longitudinally pleated and transversely folded and severed from the web to form a compact, pleated and folded article. Such a pleated and folded article is more convenient for packaging, storage and shipment; and yet permits the article, when put into use, to be readily unfolded to provide a long and wide sheet.
The present invention is described hereinafter in connection with the folding of a nonwoven fabric formed of a multi-ply laminate of creped tissue reinforced with synthetic filaments which is ultimately sold as a disposable bed sheet. Such material requires relatively careful handling to prevent wrinkling as it is very lightweight, limp and flexible. However, it is to be understood that the hereinafter disclosed method and apparatus may be used to form pleated, folded articles from heavier or more rigid materials and materials of various kinds.
Disposable products and particularly those made from nonwoven fabrics must be expeditiously handled at high speeds and in automatic, continuous manners to provide a commercially acceptable costfor the ultimate article. Thus, it is important that the apparatus for pleating and folding the article be relatively simple and capable of operating for relatively long periods of time without stoppage or maintenance.
Accordingly, an object of the invention is to provide an apparatus for and a method of pleating and folding webs to form articles, such as that described above.
Other objects and advantages of the invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIG. I is a perspective view of an apparatus embodying the novel features of the invention and for carrying out the method of the invention;
FIG. 2 is a view of a pleated and folded article formed with the apparatus of FIG. ll;
FIG. 3 is a front elevational view of the apparatus of FIG. 1;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 3;
FIG. 5 is a side elevational view of the apparatus of FIG. ll;
FIG. 6 is an enlarged side view of a drive apparatus;
FIG. 7 is a diagrammatic end view of a web folding device;
FIG. 8 is a fragmentary enlarged view of a web gripping mechanism; and
FIG. 9 is a perspective view of a drive for a web cutting blade.
As shown in the drawings for purposes of illustration, the invention is embodied in an apparatus 11 for forming a pleated, folded article 12, such as a bed sheet, shown in FIG. 2, from an elongated sheet or continuous web 14 of a material such as a nonwoven fabric formed of creped tissue with synthetic resin filaments reinforcing the creped tissue. Briefly, the preferred method of forming the article 112 from the web 14 comprises the steps of continuously moving the web 14 along a path of travel of a pleating station 15, bowing the web to have a substantially concave shape in the transverse dimension of the web, pleating the web by forcing portions of the web in a direction normal to the direction of travel at the pleating station to progressively form pleats 16 while the web and pleated portions are converging along radially extending lines to a common predetermined or focal point 117, forcing the pleats together at the focal point to form a pleated web 19, transversely folding the pleated web at a folding station 18, and severing the pleated web to provide a predetermined number of folded plies 20 for the pleated and folded article.
Also, as will be explained in detail, the pleats 16 of the web 19 are preferably forced together by a pair of compression rollers 21 (FIG. 3) which also crease and form definite fold or pleat lines in the pleated web. Preferably, the pleated web is severed by means of a continuous cutting blade 27, as best seen in FIGS. 6 and 9, in the form of an endless band which is mounted for cutting on the fly by means which moves the endless band blade 27 into engagement with the pleated web and then travels in a downward direction of travel while severing and then retracts the blade from the web after having severed the same. The preferred apparatus for transversely folding the pleated web 19 at transverse fold lines 24 and 26, FIG. 2, includes a pair of counter rotating cylinders 29 and 31 (FIGS. 6 and 7) each having a gripping means thereon for gripping the pleated web to form a fold line and for moving the pleated web in a transverse direction before releasing the same. The alternative gripping and releasing actions provide a zigzag folded article with a series of reversely formed fold lines 24 and 26 between adjacent plies 20.
Referring now in greater detail to the illustrated apparatus, the web 14 is fed forwardly from a large supply roll 33 (FIG. I) mounted on a stand 35 for feeding to a first guide bar 37 from which the web 14 travels to a means 39 for forming an are or curvature in the web. In this instance, it is preferred that the web travel in a substantially horizontal direction between the guide bar 37 and the means 39 for bowing the same and that the web be bowed with a downwardly concave, transverse cross section. As best seen in FIG. 1, the web spans the space between the guide bar and means 39 with the web being substantially in a flat plane when leaving the guide bar 37 and having a sufficiently long, unsupported span to allow the web to become progressively more arcuate as it moves to the are forming means 39.
The generally bowed cross section of the web 14 at the are forming means 39 is in the general geometric configuration formed by swinging an are from the focal point 17 to the horizontal plane in which the web 14 travels from the guide bar 37 to reach the are forming means 39. To initiate and form definite pleat lines 23 and 25 in the article, it is preferred that the are forming means 39 be formed with a plurality of straight line sections or sectors 43, each of which has a length equal to that ofa pleat, Le. a fold line 23 or 25 and a pair of adjacent plies 20. The sectors 43 are joined at juncture points 45.
On the other hand, satisfactory pleats 16 have been found by having the are forming surface curved as a true curved arcuate surface without any sectors 43 or any juncture points 45 between sectors. The illustrated are forming means 39 is the upper surface or wall 40 ofa flat vertical plate 47 although it is to be understood that rotatable rollers or substantially rounded guide bars could be used in lieu of the upper edge of the illustrated plate 47. In this instance, the plate 47 is disposed substantially vertically with the pleats being formed as the web 14 moves downwardly from the arc forming means 39 to the focal point 17 at the compression rollers 21. The plate 47 is stationary and is attached at the rear side thereof to a stationary frame 49 which is in the form of a series of horizontal and vertical bars 50 (FIG.
To form the longitudinally extending pleats which are shaped as fan fold pleats while being formed at the pleating station 17, the portions of the web 14 to be pleated are forced from the downward direction of travel to move also in directions at right angles to this downward travel direction. Preferably, at the pleating station 17 a first set of pleat formers 51 and a second set of pleat formers 53 force portions of the web forwardly and rearwardly to form fan fold lines 54 in the web 14 while it is moving along generally radial directed planes to the focal point 17 at the compression rollers 21.
To reduce the tendency of the web 14 to wrinkle, it is preferred that the arc forming surface 40 be disposed in a vertical plane 52, FIG. 5, disposed centrally of the compression rollers 21 so that the equal portions of the web 14 are forced rearwardly from the arc forming surface 40 while traveling downwardly and are forced forwardly from the arc forming surface 40 while traveling downwardly. Thus, from the vertical plane at the are forming surface 40, one half of the web 14 is being forced forwardly and one half is being forced rearwardly from a vertical plane including the overhead are forming surface 40. Also, the plate 47 is slanted downwardly and rearwardly, as seen in FIG. 5, from the plane 52 to mount the pleat formers 51 and 53 in a manner to allow rearward movement of the web while pleating.
The preferred pleat formers 51 and 53 are generally triangular in shape and the first set of pleat formers 51 are formed with wide upper ends 65 and downwardly tapering sides 67 leading to a lower, pointed, rearwardly extending ends 69 disposed immediately above the focal point 17 at the compression rollers 21. The upper ends 65 of the first set of formers 51 are secured to a bracket 71 by adjustable screws 73 which upon turning carry the upper former ends toward or from the supporting plate 47. The bracket 71 includes a transverse arcuate portion 72 parallel to and spaced from the plate 47 and attached thereto at end plates 74. The lower ends 69 of the first set of formers 51 are also supported on adjustable screws 75 threaded into a similar bracket 76 fixed at opposite ends to the vertically extending plate 47. In the illustrated embodiment of the invention, three such first pleat formers 51 are provided with each being disposed intermediate a pair of the second set of pleat formers 53. By turning the adjusting screws, the pleat formers are positioned with their upper ends 65 disposed forwardly of the plane 52 and inclined to the vertical and with their lower ends 69 disposed rearwardly of the plane 52.
The second set of pleat formers 53 have upper narrow pointed ends 77 and are disposed in radially extending planes from the focal point. The pleat formers 53 project at right angles to the vertical support plate 47 to which they are secured at inner side walls 79 (FIG. 4) thereof. As the web 14 is positioned over, i.e. forwardly of the pleat formers 53, the web 14 covers the viewing of the pleat formers in most of the illustrated FIGURES. The pleat formers 53 have norrow pointed upper ends 77 and have downwardly and forwardly inclined edges 78 along which the web is forced to travel and to begin to form the fold lines immediately as the web 14 travels across the arc forming surface 40. That is, the web 14 is constrained to project progressively forward as it travels along the edges 78 of the formers 53. At the same time, the pleat formers 51 are forcing portions of the web rearwardly towards the plate 47 while the pleats being formed are moving down along fan fold lines to converge at the focal point 17.
As best seen in FIG. 3, the longitudinally extending edges 81 and 83 of the web 14 are constrained to move inwardly and to flow along the outer ones of the second set of pleat formers 53 by downwardly and inwardly inclined web guides 85 in the form of bars which have upper ends secured to the bracket 72 and have free lower ends 87 which engage the web and force the same towards the outer sides of the pleat formers 53. In this instance, the outer edges of the web 14 provide flaps 89 which are about one-half the width of a ply 20.
The pleat lines 23 and 25 formed during the pleating operation are creased as the pleated web moves through the nip of the counter rotating compression rollers 21. The preferred compression rollers also serve as feed rollers which serve to continuously pull the web 14 across the guide bar 37 and arc former 39 and through the pleating station 15 by exerting a pull on the web. The illustrated compression rollers 21 have rough outer gritty surfaces 91 (FIG. 9) to provide a good frictional contact with the pleated web 19 to prevent a slipping or sliding movement therewith. As will be explained, the number of revolutions of the feed and compression rollers 21 is used as a control to operate the cut off means to provide predetermined and uniform lengths of pleated web for each article.
The preferred rough and gritty material on the rolls 21 is in the form of thin sheet-like material which is spirally wrapped about an internal cylinder 93 mounted on a horizontal disposed shaft 95. The respective shafts 95 for each compression roller project into bearing mounts 97 (FIG. 6) which are mountedon horizontally extending frame members 99 of a support frame 100.
At least one of the compression rollers 21 is positively driven and in this instance, one of the shafts 95 is keyed to a sheave 101, as best seen in FIG. 6, about which is trained a drive belt 103 extending to a lower sheave 105 fastened to a horizontal shaft 107 which is journaled for rotation in a pair of spaced bearing mounts 109 and 110, as best seen in FIG. 5. A sprocket 111 is also fixed to the shaft 107 and meshed about sprocket 111 is a chain 113 extending to an adjustable speed control unit 115 connected to and driven by an electric motor 117. The speed control unit allows slight adjustments in the speed of rotation of the compression rollers 21 and by turning a control handle 119 the speed of the compression rollers 21 relative to the motor speed may be adjusted to provide the desired tension in the web 14 as it is pulled through the bowing and pleating stations. The compressed and pleated web travels downwardly from the compression rollers 21 to the folding station at which the pleated web is transversely folded.
The preferred means for folding the pleated web includes a pair of counter rotating folding cylinders 29 and 31 which are mounted on parallel, horizontally disposed support shafts 125 journaled in bearing mounts 127, FIG. 6, fastened to the horizontally extended cross bar 50 of the frame 49. To assure that the folding cylinders 29 and 31 maintain their synchronism, it is preferred that they be meshed for common movement by means of ring gears 129 and 131 fixed to outer ends of the cylinders.
The preferred folding cylinders 29 and 31 each have a tuck blade 133, as best seen in FIG. 7, which extends longitudinally across a peripheral surface 135 of the cylinder and projects radially outwardly beyond the peripheral surface 135 of its respective cylinder. The tuck blade 133 on one cylinder is used to force the pleated web into an opened mouth or slot 139 of a gripper of the other cylinder. The gripper comprises a rotatable gripper blade or jaw 141 having a support shaft 143 (FIGS. 7 and 8) journaled at opposite ends in bearing mounts 145 fastened to the opposite end walls 147 of the cylinder.
The illustrated gripper is urged to an open, nongripping position by a torsion spring 149 fastened at one end thereof to the support shaft 143 and fastened at its opposite end to the bearing mount 145. The torsion spring biases the gripper shaft 143 to an open position in which an edge 151 of the gripper blade 141 is spaced from a cooperating fixed jaw or anvil 153 carried on a cylinder at the opposite side of the slot. As the folding cylinders rotate, the tuck blade 133 from one cylinder projects a portion of the pleated web 19 into the open mouth of a gripper on the other cylinder. Then the gripper blade 141 is closed on the inserted web by means of stationary cams 155 which are fixed to the stationary bearing mounts 127 for the cylinder support shafts 125. The cams 155 have an apex 157 which earns a cam follower 159 on a lever 161 fixed to the gripper blade shaft 143 to rotate the gripper blade toward the anvil 153 to clamp the web. As the gripper blade moves to clamp the web, the tucker blade of the other cylinder is retracted by its cylinders rotation. As this gripper continues to move downwardly, it pulls the pleated web against its trailing peripheral surface 135. When this gripper begins to move upwardly on the outer side of the cylinder, its cam follower 159 moves from the cam apex onto cam surface 165 under the urging of torsion spring 149 which turns the shaft 143 and the gripper blade to its inoperative or open position thereby releasing the folded portion of the pleated web which drops onto a stationary support 166.
The folding cylinders 29 and 31 are identical in operation with one tucker blade 133 always available each half revolution of the cylinders to wrap a portion of the web thereon and carry the same about its surface in a downwardly and arcuate direction to a point at which the cams 155 pivot the levers 161 to allow the gripper blades to release the pleated web.
To assure that each of the articles is folded in the same manner, the folding cylinders 29 and 31 are driven in timed relationship to the speed of web travel and share a common drive with the compression rollers 21 which also serve to feed the web 14. More specifically, the shaft 197 (FIG. 6) driven by the sprocket 111 and chain 113 is provided with a gear 167, as best seen in FIG. 5, which is meshed with the ring gear 129 for the folding cylinder 29. Also, the operation of the cutting blade 27 is timed to the web feed so that the same length of web is cut for each article which, in this illustrated embodiment of the invention, is seven feet for a bed sheet. After severing the pleated web 19, the remaining portion or trailing end of the pleated web falls over the previously overlapped zigzag folds and the now pleated and folded article may be conveyed off or left to receive another article and form a stack of articles before being removed.
The pleated web 19 is severed to provide a straight line out which is normal to the path of web travel and which is not sharp or irritating to the skin. The cut must completely sever each of the eight plies, which in turn may be multi-layered. The cutting blade 27 cuts on the fly; that is, the blade is cutting while traveling downwardly with the pleated web 19. A preferred manner of cutting the pleated web is by means of the continuous band kind of blade 27 which is continuously driven for movement about an endless path and between a pair of wheels 169 and 171. A sharp cutting edge 173 on the cutting blade 27 faces the pleated web. When the band blade 27 is not cutting and is in an inoperative position, as seen in FIG. 6, it is positioned in a plane inclined to the vertical with a lower cutting run for the blade between the wheels 169 and 171 being much closer to the pleated web 19 than the upper or return run of the blade which is spaced at a considerable distance from the pleated web. As will be explained, the upper return run of the blade remains spaced from the web when the orbital mechanism causes the lower run of the blade to move into cutting contact with the pleated web.
The wheels 169 and 171 about which the endless band blade 27 travels are secured to the outer ends of shafts 174 and 175 which are disposed parallel to one another and mounted in upstanding, U-shaped brackets 177 fixed to an orbital carriage 179. More specifically, the upstanding brackets 177 carry bearings 181 which journal the wheel supporting shafts 174 and 175 for turning about axes which are more inclined to the horizontal than to the vertical. In this instance, the wheel 169 is an idler wheel while the wheel 171 is a drive wheel for the band blade 27; and this latter drive wheel is driven by an electric drive motor 183 which is also fastened to and supported by the carriage 179. The drive motor has a rotatable shaft on which is secured a sheave 167 meshed in driving engagement with a drive belt 191 (FIGS. 6 and 9) extending to and driving another sheave 193 fixed to an end of the supporting and drive shaft 175 for the blade driving wheel 171. In this instance, the motor 153 is continuously driven so that the band blade 27 is also continuously traveling about its endless path and is ready for cutting.
For the purpose of moving the lower run of the band blade 27 toward the pleated web 19 and then downwardly therewith and then away from the pleated web, the carriage 179 which supports the drive and idler wheels 169 and 171 is mounted for orbital movement to carry the blade through the above described movements. More particularly, the carriage includes a carriage base 195 in the form of a flat plate which supports on its upper surface the U-shaped brackets 177 for the wheels and the motor 183. The carriage is supported at its forward end, that is, the end adjacent the band blade 27, by an eccentric means 197 and is supported at its rearward end by a pair of support rods 199 projecting through and having slidable movement within guide sleeves 201. The guide sleeves 201 are pivotally mounted to turn about horizontally extending axes by pairs of pivot pins 203 which project into openings in upstanding legs 205 of angle shaped brackets 207 fixed to a lower, horizontally disposed, frame plate 209 which is a stationary plate. Thus, the rearward end of the carriage base may pivot about an axis through the pivot pins 203 as it moves towards or from these pivot pins with the rods 199 sliding in the sleeves 201.
The eccentric means for shifting the carriage 179 is preferably in the form of a pair of disks 211 which are fixed to opposite ends of a rotatable shaft 213 to be turned thereby. The disks 211 rotate with and about the longitudinal axis of the shaft. The disks 211 are connected to the carriage base at positions offset from the turning axis thereof which axis is coincident with the longitudinal axis of the shaft 213 so that during rotation of the disks, the carriage partakes of an orbital movement about the longitudinal axis of the shaft 213. The illustrated eccentric disks 211 have apertures 217 which are offset from the turning axis of the disks by a predetermined throw. Pins 219 fastened to the carriage base 195 project into the apertures 217 in the disks. Thus, the forward end of the carriage is supported at pins 219 which are free to turn in the apertures 217 in the disks 211 as the disks turn. As the shaft 213 turns the disks 211, the pins 219 move in a circular path about the axes of the disks 211 and the shaft 213.
During a revolution of the shaft 213, the pins 219 move upwardly over the axis of the shaft 213 and towards the pleated web 19 to bring the lower run of the blade 27 into contact with the web and then as the pins 219 move downwardly the carriage lowers the blade 27 while it is cutting the pleated web. When pins 219 move rearward and beneath the axis of the shaft 213, the carriage base 195 is moved rearwardly to retract the blade 27 from the pleated web which is now completely severed by the blade. In this manner, the carriage will move about the axis of the supporting shaft 113 from a rearward inoperative position, such as shown in FIG. 6, to a forward position to sever the pleated web 19.
The shaft 213 is journaled in a support 221, as best seen in FIG. 9, and has fixed thereto a sprocket 222 driven by a chain 223 which extends downwardly to a sprocket 224 driven by a variable speed control device 225, which, in turn, is driven by a motor 226. The motor 226 is operated at predetermined timed intervals by a timing device or counter (not shown) to assure that the same length for each article 12 is attained. As an alternative to having the chain 223 driven by the separate motor 226, the chain 223 may be connected through suitable intermittent drives (not shown) to the motor 117 so that shifting of the carriage 179 and the blade 27 is correlated directly with the feeding of the pleated web 19 by the compression rolls 21.
To assure that the pleated web 19 has each of its plies severed and that the pleated web is not pushed laterally by the cutting blade 27 to the extent that a pleat or ply would not be severed, a backing means 229, as best seen in FIG. 2, is provided on the side of the pleated web opposite the cutting blade to laterally constrain the continuously traveling pleated web 19 for as long as the blade is cutting and moving downwardly therewith. Thus, the backing means holds the pleated web from moving laterally while permitting the blade edge to penetrate through the web and into the backing means as the web is continuously traveling downwardly.
Preferably, the backing means 229 is relatively inexpensive in construction and need not be adjusted or repositioned when it is desired to change the length of web being severed. More specifically, the illustrated backing means is in the form of a brush anvil 231 formed with a plurality of bristles 233, as best seen in FIGS. 5 and 6, the tips of which define a cylindrical surface 235 which holds the web 19 against lateral movement, which is to the right as viewed in FIG. 6, from the cutting blade 27 which penetrates through the pleated web and separates the bristles while penetrating through the brushs outer cylindrical surface. The illustrated brush anvil is rotated about its support shaft 237 which extends generally horizontally and isjournaled at its opposite ends in bearing mounts secured to depending stationary vertical frame members 239, one of which is seen in FIG. 6. As illustrated in FIG. 1, the support shaft 237 has a sheave 241 fixed to one end thereof with the driving belt 103 for the compression rolls 21 in driving engagement with the sheave 211. It is preferred that the brush anvil be driven with a surface speed which matches the linear speed of pleated web 19 and the downward travel speed of the cutting blade 27 so that the cutting blade, once having penetrated between the bristles, travels downwardly therewith at the same rate until retracted from between the bristles.
The cutting blade edge is sufficiently sharp to readily sever the pleated web 19 but it does not cut or sever the bristles 233 of the brush anvil 231 as the bristles are sufficiently tough and flexible to deflect and to part prior to being cut. The preferred bristles are formed of nylon or other synthetic material. While the bristles 233 are deflected readily by the cutting blade, they nonetheless have a collective rigidity, when pressed on outer ends thereof by the pleated web 19, to hold it against any significant lateral displacement during the severing operation. As the blade 27 may be inserted into any portion of the cylindrical surface of the brush anvil and need not be aligned with fixedly positioned grooves therein, the brush anvil is readily adapted to changes in length for the cut without having to have its timing readjusted or any portions thereof repositioned.
A brief description of the operation of the illustrated apparatus for pleating and folding the elongated web 14 will be given for the purpose of facilitating an understanding of the invention. The web 14 is wide, elongated and continuously stripped from a supply roll 33 and is continuously fed forwardly to a pleating station 15 at which the web is pleated. At the pleating station 15, the web is transversely bowed and is directed to change its direction of travel from a generally horizontal direction to a downwardly direction. The means 39 for bowing the web includes a plurality of straight line adjacent sections or sectors 43 which define a generally arcuate or bowed support surface for the web 14 prior to its traveling downwardly. The sectors 43 intersect at corners 45 which serve to form and to initiate fan fold lines in the web 14 as it travels across the sectors 43.
As the web 14 travels downwardly, it is forced to move into a fan fold shape by means of a pleat forming means comprising first and second sets of pleat formers 51 and 53 which extend downwardly to adjacent a focal point at a pair of compression rollers 21. More specifically, the illustrated pleat formers 51 and 53 are triangular shaped members which function to force portions of the web to move progressively in other directions, viz. forwardly or rearwardly, relative to the direction of web travel, viz. downwardly in a vertical plane 52, as best seen in FIG. 5, until full width pleats are formed adjacent the lower ends of the pleat formers 51 and 53. The pleat formers 51 and 53 are generally radially disposed from a focus at the nip of the compression rollers 21. The pleat formers 51 have their wide ends uppermost and have their web engaging surfaces transversely disposed while the pleat formers 53 have their narrow ends uppermost and have their web engaging edge surfaces longitudinally disposed.
The compression rollers 21 are driven by a motor 117 to feed the compressed and pleated web 19 downwardly to a pair of underlying folding cylinders 29 and 31 which alternatively grip the pleated web 19 and form a zigzag folded article with a series of reverse fold lines 24 and 26 between superimposed plies. The folding cylinders 29 and 31 each have a tuck blade 133 for forcing the web into a gripping jaw in the opposite cylinder which then rotates to carry the gripped portion of the web laterally to a point where a can 155 actuates a cam follower 159 to open the gripper blade and release the fold 241 or 26 at which time the opposite gripper and tuck blade are moving into position to carry the web laterally in the opposite direction to form the next succeeding ply for the article.
After a predetermined number of folds are formed, the motor 226 is operated to bring the cutting blade 27 into operative cutting position to sever the pleated web 19 on the fly to provide a predetermined length for the article, eg a bed sheet having a 7 foot length. More specifically, as about 7 feet of the pleated web 119 has been fed downwardly by the compression rollers 21, the motor 226 shifts the blade supporting carriage 179 through an eccentric means 197 to engage the lower run of the endless band blade 27 against the pleated web 19 which is being backed by the rotating brush anvil 231. Preferably, the blade 27 severs through the thickness of the pleated web 19 and travels into the bristles of the brush anvil 231 as it is simultaneously moving downwardly at substantially the same speed at which the web is traveling. This provides straight line, square cornered ends for the bed sheet and assures a generally rectangular shape for the unfolded bed sheet.
Preferably, the pleated web 19 is fed continuously and the folding cylinders 29 and 31 continuously rotate with the cutting blade 27 being periodically moved into cutting engagement with the pleated web after predetermined timed intervals. Thus, a succession of folded and pleated articles will be deposited on an underlying support and suitable transfer or conveyor means (not shown) may be used to remove each folded and pleated article from beneath the folding cylinders 29 and 31.
Thus, it will be seen from the foregoing that there is provided a relatively simple, automatic and inexpensive apparatus which is particularly useful for pleating and folding wide and elongated webs to form a compact article and in a continuous manner. The apparatus is capable of handling relatively limp, lightweight and flexible material such as a nonwoven fabric web formed of a multi-ply laminant of creped tissue and reinforcing filaments.
While a preferred embodiment has been shown and described, it will be understood that there is no intent to limit the invention by such disclosure but, rather, it is intended to cover all modifications and alternate constructions falling within the spirit and scope of the invention as defined in the appended claims.
1. An apparatus for forming longitudinally pleated and transversely folded articles from a continuous web, said apparatus comprising means for continuously feeding said web along a path of travel in a first direction, means for transversely bowing said web to have a substantially curved transverse cross section, said feed means continuously moving said web after bowing along a path in a second substantially vertical and downward direction at an angle to said first direction, means for pleating said web by forcing portions of the web at spaced locations to project normal to said second direction to form progressively increasing widths for each pleat while moving the pleats along radial lines toward a predetermined focal point, means for forcing said pleats together at said focal point to form a pleated web while said web is continuing to travel downwardly, means for transversely folding said pleated web to provide a series of overlapped pleated plies for the article, means including an endless cutting band having a thin sharp cutting edge for severing said pleated web while it is traveling at predetermined intervals to provide a predetermined and equal number of overlapped plies for each of said pleated and folded articles, said endless band being in a plane disposed at an acute angle to the vertical with one run thereof closer to the pleated web and movable in an orbital path to move laterally to engage said pleated web to travel in a substantially rectilinear downward movement with said pleated web and to retract laterally from the path of said pleated web while the other run remains spaced from cutting engagement with said pleated web and support means for shifting said cutting band along the orbital path from a position spaced from said pleated web into engagement therewith for traveling with said pleated web downwardly in the direction of pleated web travel and at substantially the same speed of pleated web travel to sever said pleated web transversely and then retracting from said pleated web.
2. An apparatus in accordance with claim 1 in which said support means includes a carriage for carrying said enless band, an eccentric means for moving said carriage and said cutting band in said orbital path from a position spaced laterally of said pleated web into engagement therewith to engage the pleated web and to travel downwardly substantially in the direction of pleated web travel and to move later-ally away from the pleated web after having severed the same and to move upwardly to complete said orbital path.
3. An apparatus in accordance with claim 1 in which said means for folding said pleated web comprises a pair of counter rotating cylinders between which said pleated web travels, gripping means on each of said cyl-- inder for gripping the pleated web at spaced locations to form fold lines and to carry the pleated web alternately in opposite directions and to release the folds after having transported the same thereby forming overlapped zigzag folded plies for said article.
4. An apparatus in accordance with claim 3 in which said means for forcing the pleats together comprises a pair of counter rotating rolls which define a nip to compress the pleats together and which have rough surfaces thereon for exerting a pull on said web to feed the web forwardly along its path of travel, and in which said folding cylinders are disposed vertically beneath said compression rollers.
5. An apparatus in accordance with claim 1 in which said pleating means comprises first and second sets of elongated web engaging guides each extending radially outward from said predetermined point and in which said first and second set of guides force portions of said web in opposite directions from its direction of travel and force these portions through substantially equal adjacent said predetermined point.