US3572689A

US3572689A - Method and apparatus for folding articles

Info

Publication number: US3572689A
Application number: US744009A
Authority: US
Inventors: James A Murphy; Charles A Lee; Warren R Furbeck; Philip G Day
Original assignee: International Paper Co
Current assignee: International Paper Co
Priority date: 1968-07-11
Filing date: 1968-07-11
Publication date: 1971-03-30
Anticipated expiration: 1988-03-30

Abstract

A series of flat articles are advanced along a path at regular intervals and are folded by continuously traveling fingers which engage an article intermediate its ends and fold the same. The fingers advance the articles to a station at which the folded articles are deposited as the fingers automatically withdraw from the folds. The folded articles may be abutted seriatim into a stack within an accumulator in the form of a conveyor traveling a speed considerably slower than the speed of the traveling fingers.

Description

United States Patent lnventors James A. Murphy Toronto,Ontario, Canada; Charles A. Lee; Warren R. Furbeck, Knoxville, Tenn.; Philip G. Day, Cooksville,Ontari0, Canada Appl. No. 744,009

Filed July 11, 1968 Patented Mar. 30, 1971 Assignee I International Paper Company New York, N.Y.

METHOD AND APPARATUS FOR FOLDING ARTICLES 13 Claims, 16 Drawing Figs.

US. Cl 270/70 Int. Cl B65h 45/16 Field of Search 270/61,

[56] References Cited UNITED STATES PATENTS 2,238,251 4/1941 Dahlman 93/1 2,470,072 5/1949 Lawrie 270/70 2,848,220 8/1958 Anderson Primary Examiner-Lawrence Charles A!t0rneyAnderson, Luedeka, Fitch, Even and Tabin ABSTRACT: A series of fiat articles are advanced along a path at regular intervals and are folded by continuously traveling fingers which engage an article intermediate its ends and fold the same. The fingers advance the articles to a station at which the folded articles are deposited as the fingers automatically withdraw from the folds. The folded articles may be abutted seriatim into a stack within an accumulator in the form of a conveyor traveling a speed considerably slower than the speed of the traveling fingers.

Patnted March 30, 1971 8 Sheets-Sheet 1 WM 9% AQ E 5 L 1 Ia mmk km mmmR & 9m

mm an Patented I March 30, 1971 8 Sheets-Sheet 2 Patented March 30, 1971 8 Sheets-Sheet :5

Patented March 30, 1971 8 Sheets-Sheet 5 Patented March 30,- 1971 85heets-Sheet '7 Patented March 30, 1971 8 Sheets-Sheet 8 METHOD AND APPARATUS FOR FOLDING ARTICLES This invention relates to an apparatus for and a method of folding articles and also to collecting folded articles seriatim into a row or stack of abutted articles.

The present invention is particularly useful for folding relatively flat, flexible articles such as sheets, laminae or the like. The illustrated embodiment is described in connection with, but is not limited to, the folding and stacking of disposable diapers which basically include an absorbent pad of cellulosic material with an envelope thereabout comprised of a facing sheet for disposing against a childs skin and an outer backing sheet. The diapers are relatively flexible and limp and the envelope may be damaged by scuffing, tearing or soiling. The preferred embodiment of the invention may be used to fold a steady stream of diapers issuing from a production line at relatively high rates such as, for example, 150 diapers per minute.

To fold continuous streams of articles at such relatively high rates in a neat and orderly manner, has heretofore required relatively expensive, complex equipment employing elaborate electrical or vacuum control systems to fold, transport, orient and stack the diapers. With the present invention, a continuous stream of diapers are folded, transported and oriented into abutted rows or stacks with a relatively simple mechanical apparatus.

Accordingly, an object of the invention is to provide an improved apparatus for and method of folding articles, such as diapers.

A more specific object of the invention is to provide a simple mechanical arrangement in which traveling pins fold, transport and position diapers for collection into rows or stacks of abutted articles.

Other objects and advantages of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings in which:

FIG. I is a side elevational view of an apparatus for folding diapers and collecting them in a stack or row;

FIG. 2 illustrates a single diaper prior to folding;

FIG. 3 shows a collection of folded diapers disposed in a row;

FIG. 4 is a horizontal plan view of the apparatus shown in FIG. I, taken substantially along the line 4-4 of FIG. 1;

FIG. 5 is a horizontal sectional view taken substantially along the line 5-5 of FIG. 1, showing a portion of the drive for the apparatus of FIG. I;

FIG. 6 is an enlarged vertical sectional view of a portion of the apparatus shown in FIG. I, taken substantially along the line 6-6 of FIG. I;

FIG. 7 is an enlarged vertical sectional view taken along the line 7-7 of FIG. I, showing the side conveying belts of the apparatus shown in FIG. I;

FIG. 8 is an enlarged fragmentary view of a portion of the apparatus shown in FIG. I taken substantially along the line of FIG. I, A

FIG. 9 is an enlarged detailed view of a folding finger and its support as used in the apparatus shown in FIG. I;

FIG. III is an enlarged, vertical sectional view taken along the line III-I of FIG. I showing a portion of the drive for the fold fingers shown in FIG. 9;

FIG. II is an enlarged, vertical cross-sectional view taken along the line II-II of FIG. 1 showing a drive for side conveyor belts of the apparatus shown in FIG. 1;

FIG. I2 is an enlarged, vertical sectional view of a portion of the apparatus shown in FIG. I taken along the line I2I2 of FIG. 1;

FIG. I3 is an enlarged, vertical sectional view taken along the line 13-13 of FIG. I showing a central gearbox and drives therefrom for the apparatus shown in FIG. 1;

FIG. 14 is an enlarged, vertical cross section taken substantially along the line'M-M of FIG. I and showing a drive for an accumulating conveyor for the apparatus shown in FIG. 1;

FIG. I is a vertical, sectional view taken substantially along the line IS-IS of FIG. 1 showing a discharge conveyor for the apparatus shown in FIG. I; and.

FIG. I6 is the diagrammatic view showing in phantom lines a sequential folding, transporting and positioning of a diaper by the apparatus of FIG. I.

As shown in the drawings for purposes of illustration, the invention is embodied in a method of and apparatus for, very generally, folding a continuously moving stream of articles, such as a disposable diaper 17 (FIG. 2) issuing continuously from a diaper-making machine (not shown) and for collecting the diapers into a row or stack 19, as best shown in FIG. 3, of folded diapers. Partly for historical reasons, the term stack will be used herein to refer to this collection of folded diapers arranged with their flat sides abutting in a relatively neat array, irrespective of the fact that in the preferred embodiment of the invention the diaper collection extends horizontally rather than vertically as was generally the case with stackers of the prior art.

As will be explained, the present invention is adapted to operate continuously and at a relatively high rate of speed, for example, diapers per minute or in excess thereof and to fold the diapers neatly and evenly so that the stack of diapers is aligned in a neat array for a subsequent packaging operation. The diapers may range inlength from approximately l4 to 18 inches and in width from about 9 to l2 inches, but the invention is not limited either to diapers or to diapers of these sizes. The diapers are folded midway between embossed areas at the ends 21 of the diapers at the location of tacking embosses 23 (FIG. 2) which tack the innermost portion of folded pleats 25 along the sides of the diaper. The illustrated diaper is formed generally within a creped tissue cover or envelope with an internal absorbent padof wood pulp (not shown). The present invention has the capability of folding such a diaper without tearing or soiling the creped tissue cover and folding the diaper evenly so that the resulting legs 27 (FIG. 3) have their ends 21 evenly depending from a center fold line 29. Preferably, the diapers are stacked with the vertical sides 28 of the legs 27 aligned for facilitating a subsequent packaging of a group of diapers.

As an aid to understanding the invention, the preferred method of folding and stacking the diapers 17 will be described first. In the diaper-making machine (not shown), the diapers are formed in a continuous strip which is severed to form individual diapers at a high rate of speed, e.g., I50 or more diapers per minute. These issue from the diaper-making machine for folding according to the present invention. As the diapers leave the diaper-making machine, they are transferred directly to an input carrier 31 (FIG. I) which is in the form of an endless conveyor or belt 33 movable along an upper run to convey the diapers, which are disposed longitudinally at regular predetermined intervals and are in a flat unfolded condition, from right to left as viewed in FIGS. I and I6. The belt 33 is driven in timed relationship to the diaper machine so that the diapers traveling leftward along this first predetennined path arrive at regular intervals at the left end of the input conveyor and are guided by a curved chute 35 which constrains the flat diapers to follow a curved path.

As the diaper leaves the curved chute, as best seen in FIG. I6, at least one folding pin or finger 37 catches or engages the diaper at a predetermined portion, preferably at the center, at what will be the fold line 29, and moves with the diaper while holding it against the lower run of the conveyor belt 33 traveling rightward along this second predetermined path. The folding finger 37 and the belt 33 move at the same velocity, holding the diaper against slipping and shifting. If the diaper were allowed to slip on the fold finger 27, one leg would become misaligned from the end of the other legv or one leg of the diaper would become longer than the other leg'of the diaper. The finger 37 and belt 33 carry the diaper forward (to the right in FIG. 16) to and through a former 39 which includes a plate 41 for compressing the diaper legs 27 together and forming a definite fold line 29 at the location of the fold finger 37. As the diaper exits from the former 39, the diaper legs 27 swing down as the diaper pivots about its fold 29 and fold finger 37. The now vertically disposed folded diaper moves into a receiving means in the form of a takeoff conveyor 43 which includes a pair of side belts 45 (FIG. 4) which engage the opposite vertical sides 28 of the diaper legs while a bottom conveyor belt 49 disposed on a belt support 48 (FIG. engages the ends 21 of the diapers to move the diapers along a third predetermined path. The takeoff conveyor 43 and each fold finger 37 travel at substantially the same speed, and the takeoff conveyor 43 supports the diapers as the fold finger 37 automatically withdraws from the fold 29. The now folded diaper is carried forward to an accumulator 51 which causes the spaced diapers 17 to abut and form the stack 19.

In the preferred embodiment of the invention, the accumulator 51 is generally similar to the takeoff conveyor 43 in that it has a pair of side belts 53 for engaging the sides 28 of the diaper and a bottom belt 55 for engaging the ends 21 of the diapers. These accumulator belts travel at a speed significantly slower than the takeoff conveyor speed so that the folded diapers which are spaced from one another, as best seen in FIG. 3, in the takeoff conveyor abut at fiat faces 47 and form a stack in the accumulator. Thus, flat, unfolded diapers disposed end to end are folded and stacked in a continuous row.

Proceeding now with a detailed description of the preferred embodiment of the apparatus for carrying out the invention, the input conveyor belt 33 is shown being moved along a downward incline from right to left in FIGS. 1 and 16 toward an idler roll 59 about which the belt reverses its direction of movement and travels rightwardly to an opposite drive roll (not shown). The diapers on the belt 33 have been deposited thereon from a diaper-making machine wherein the diapers 17 are formed in a continuous strip and then cut into individual diapers delivered end on to the belt 33. The belt 33 may be driven at a speed which is slightly faster than the speed of travel in the diaper-making machine with the result that the ends 21 of successive diapers l7 become spaced a predetermined distance.

Along the upper run, the belt 33 is disposed on the upper surface of an inverted support channel 65 (FIGS. 6 and 7) which is fastened along its downtumed edges to a pair of parallel plates 67. The plates 67 are secured to and supported by angle shaped brackets 69 (FIG. 7) bolted to vertical columns 71 which are in the form of angle members fastened at lower ends (FIG. 1) to a main support base 73 extending beneath the entire apparatus. As best seen in FIG. 1, the channel 65 is inclined downwardly from right to left and carries bearings 74 at its left end to journal the idler roller 59 for rotation about a substantially horizontal axis. It will be appreciated that the opposite end of the conveyor belt 33 is supported by a channel similar to the channel 65 and is wrapped about a drive roller (not shown).

A diaper moving to the left end of the conveyor belt 33 at the roller 59 moves into an inlet end of the curved chute 35 defined between the arcuately curved belt and a curved plate 72 which is spaced from the belt by a distance greater than the thickness of a diaper. The curved plate 72 is bent on an arc concentric with the adjacent arcuate curve of the belt 33 and terminates at a lower end defining an outlet for the curved chute 35. The diapers travel through the chute 35 at the speed of the belt 33 without slipping relative to the belt.

At what is defined as a first station, the diaper is released at the outlet end of the chute 35 so that the leading end of the diaper falls free, moving rightward and downward under the effects of inertia and gravity. As the center of the diaper emerges from the chute 35, it is caught by at least one fold finger 37 and held against the belt 33, the finger and belt thereafter moving together at the same velocity from this first station. This provides the necessary gripping force for holding the diaper 17 at the fold 29 and prevents the slipping of one of the diaper legs 27 relative to the other diaper leg. The fold finger 37 forces the diaper against the conveyor belt 33 as it is guided along its return run by a dead plate 75 (FIGS. 1, 6 and 16) which extends from adjacent the idler roller 59 to an idler roller 77, as best seen in FIG. 1. The dead plate 75 is supported by suitable studs 79 (FIG. 6) extending upward to an overhead plate 81 which spans horizontally across the brackets 83 fastened at their lower ends to main frame legs 87 fastened to the frame base 73. The dead plate 75 guides the belt 33 for substantially horizontal movement to adjacent the idler roller 77 from which the belt 33 moves upward and rightward to another idler roller 89 (FIG. l)joumaled in the support frame plates 67, and the belt 33 is suitably supported until it reaches the driving roll (not shown) at the right end of the input conveyor 31.

At a second or folding station, the finger 37 pulls the diaper rightward through the former 39 to fold the diaper intermediate its ends. The former 39 includes, in this instance, the left end of the belt 33 and the dead plate 75, which functions as the upper portion of the former 39, and the forming plate 41 (FIG. 16), which functions as the lower portion of the former 39. The diaper legs 27 are compressed between the lower forming plate 41 and the belt33 at the left end of the dead plate 75. The forming plate 41 is spaced from the belt 33 and dead plate 75 at a predetermined distance by a pair of spaced bars 95 which are fastened to the brackets 83 (FIG. I) so that the diaper legs 27 are pressed together with a compressing force as the diaper is pulled through the narrow slot between the belt 33 and the forming plate 41. As best seen in FIGS. 1 and 16, a downwardly curved arcuate bend 93 is formed on the left end of the forming plate 41 to provide a smooth guiding and supporting surface for camming the diaper legs together and into a position for easy entry into the entrance of the former 39.

In the present instance, the diapers 17 are folded, conveyed forwardly and oriented in proper position by the fold fingers 37 as the fingers are carried by an endless band such as a chain 99 along a portion of an orbital path. At a third or transfer station, the fold fingers 37 are automatically retracted from the fold 29 of the diaper. In the apparatus as shown in the drawings, the retraction is achieved by means which move the fingers outward from the path which the diapers 17 are constrained to follow, the diapers being directed along a centerline 101 (FIGS. 4 and 5) through the takeoff conveyor 43 to the accumulator 51.

As best seen in FIGS. 4 and 5, it is preferred that there be two sets of folding fingers 37 on respective chains 99 disposed on opposite sides of the centerline 101 with a finger in each set matched with and extending into alignment with a finger of the other set with which it cooperates during engagement with the diaper. The inner free ends 102 of the fingers 37 are quite close together when they first engage a diaper and move through the former 39, but the free ends 102 continually and gradually move apart as they convey the diapers into position between the side belts 45 (FIG. 4) of the takeoff conveyor 43, at which point the fingers 37 retract fully from the diaper. After withdrawal from a diaper, the fingers continue to move to the right (FIGS. 4 and 5) to a pair of sprockets 103 which define the end of the forward travel for the chains 99. At the sprockets 103, the chains 99 travel downward, as best seen in FIG. 1, to a lower sprocket 105 and then return to the left, as seen in FIG. 1, to another lower sprocket 107 at which the chains travel upward to an overhead sprocket 109 to begin their forward rightward run.

In the preferred embodiment of the invention, the fold fingers 37 are rigid, cylindrical rods or pins which have their free ends 102 projecting from a bracket 107 attaching their other ends to respective chain links (FIG. 9). Each fold finger 37 has a cylindrical collar 109 secured to it, and the collar is adapted to ride along an upper guide rail 111 (FIGS. 6 and 9) which is supported by upstanding brackets 113 bolted to the upper flange of the channel frames 85. These channel frames 85 are supported on the

frame legs

71 and 87 and diverge from the centerline 101 therebetween. The chains 99 are guided along their rightwardly extending, diverging paths by guide bars 115 which are inserted between the side plates of the chain to engage the conventional rollers on the chains 99. These guide bars 115 are fastened to the outer sides of the brackets 113, as

best seen in FIG. 6. The weight of the transported diaper tends to pivot the inner free ends 102 of the fold fingers downwardly about the respective chains 99. To limit this pivoting, the other ends of the fold pins abut and ride along the underside of guide bars which extend parallel to and along the upper runs of the chains 99. The bars 90 are suitably fastened by brackets to the channel frames 85. Along the lower and return run, the chains 99 and the collars 109 for the fold fingers 37 slide along lower guide rails 119 (FIG. 6) supported by angles 121 fastened to the

respective frame legs

71 and 87.

With the present invention, the diapers 17 are folded as they move along in a continuous stream without the use of complicated sensing mechanisms and control systems for timing the various operations. The timing of the various mechanisms is obtained by timing the travel speed of the various conveyors to the fold fingers 37. For instance, the fold finger chains 99 are driven at a speed corresponding to that of the conveyor belt 33 by the lower right sprockets (FIGS. 1 and 10) which-are joumaled in bearing in bearing mounts I23 carried by brackets 125 which (as best seen in FIG. 10) are fastened to the lower flanges of the channel frames 85. A drive sprocket 127 has a hub suitably fastened to the hub of sprocket 105 at locations internally of the bearing mounts 123 so that the

sprockets

105 and 127 turn together. Wrapped about the sprockets 127 are driving chains 129 extending downwardly to sprockets 131 fixed to a drive shaft 133 journaled in bearings 135 disposed in mounting blocks 136 fixed to the main frame base 73. The drive shaft 133 is disposed for rotation about a generally horizontal axis and receives a driving torque at its right end (as seen in FIG. 10) from a chain 137 carried by a sprocket I39 fixed to the drive shaft 133. As best seen in FIGS. I and 5, this chain 137 is tensioned by an idler 140 and extends rightwardly and upwardly to a sprocket 141 fixed to an output shaft 143. The shaft 143 is driven through a gearbox 145 by a line timing shaft 147 extending rightwardly to the diaper-making machine. The line timing shaft 147 provides the power and the timing for driving each of the various drives for the apparatus as will be described. Thus, it will be seen that through this chain and sprocket drive, the folding fingers 37 are driven in timed relationship to the diaper-making machine which is delivering the diapers to the inlet side of the input conveyor 33 so that the folding fingers 37 remain in a predetermined and timed relationship to meet the midpoint of the diapers 17 as they emerge from the curved chute 35.

As the fold fingers 37 withdraw from the diapers 17, as best seen in FIG. 4, the side belts 45 of the takeoff conveyor 43 engage the vertical sides 28 of the diaper legs and center the diapers on the centerline 101 of the takeoff conveyor. To this end, the side belts 45 are guided by converging ends 149 of a pair of dead plates 151 spaced on opposite sides of the centerline 101 to form a mouth at the inlet end of the takeoff conveyor 43. The dead plates are disposed vertically and beneath the plane of travel of the fold fingers, and the dead plates are generally parallel from the converging inlet ends 149 to adjacent the discharge end of the takeoff conveyor. The dead plates 151 are supported by horizontally extending studs 153 which extend to and are bolted to brackets 155 (FIG. 10) upstanding from and fastened to the upper flange of the channel frames 35. Adjacent the inlet ends 149, the side belts 45 are wrapped about an idler pulley 156 mounted on a vertically disposed shaft 158 which is journaled in a bearing mount 160 (FIG. 7) on the upper flange of channels 85.

To drive the side belts 45 at the proper speed, they are wrapped about knurled drive rolls 157 fastened to upstanding drive shafts 159 (FIG. 11) to rotate about the vertically disposed axes of these shafts. From the drive rolls 157, the belts are wrapped about tension rollers 161 which are journaled on upstanding posts 163 fastened at their lower ends in crank arms 165. These crank arms are mounted on a horizontal support 167 spanning and fastened to a pair of frame legs 37. The crank arrns are pivoted to and secured in positions to assure that the side belts 45 have the proper tension.

The drive shafts 159 are joumaled in upper bearings 169 on the horizontal support and in lower bearings 171 on the base plate 73. Intermediate these bearings, a pulley 173 is fixed to each drive shaft 159 and these pulleys are driven by a drive belt 175 (FIGS. 5 and 11) which is tensioned by an idler pulley 177 on a shaft supported by a crank arm 179. The belt 175 is driven by an output sheave 181 of a right angle, gear drive unit 183 which in turn is provided with an input sheave 135 driven by a belt 187 extending forwardly to a sheave 109 fixed on a jack shaft 191 (FIG. 5). The jack shaft 191 is disposed generally horizontally and adjacent the frame base 73 and, as best seen in FIG. 13, carries an attached sheave 193 about which is trained a belt 195 extending upwardly to a pulley 197 fixed to an output shaft 199 of the main gearbox 145 which is driven by the line timing shaft 147. In this manner, the side belts 45 may be driven at the same speed of travel as the fold finger chains 99.

The takeoff conveyor 43 also includes the bottom belt 49, which engages and supports the ends 21 of the diaper legs 27, and extends generally horizontally from the former 39 to adjacent the accumulator 51. At its left end, the bottom belt 49 is wrapped about an idler roll 201 supported on a shaft 203 (FIG. 4) joumaled in bearings 205 which are slideably ad justable upon turning screws 207. The bearings 205 and the adjustment screws 207 for the idler roll 201 are mounted in brackets 209 (FIG. 1) fastened to the channel frames 85. During movement along its upper run, the bottom belt 49 is supported by a dead plate 211 (FIG. 7) which is fixed to a horizontal cross brace 213 extending between the webs of the channel frames 85.

To drive the bottom belt 49 at the same speed as the side belts 45 and the fold fingers 37, the bottom belt is, at its forward discharging end, wrapped about a driving roll 215 (FIG. 11) fixed to a horizontal shaft 216 rotatably mounted in bearings 217' in turn mounted on hearing mounts 219 on the horizontal support 167. One of the ends of the shaft 216 extends outwardly and carries a sheave 221 about which is trained a belt 223 extending to a sheave 225 (FIGS. 5 and 10) fastened to the jack shaft 133, previously described as being suitably connected to the line shaft 147 and driving the folding finger chains 99. Thus, the jack shaft through the drive described will cause the bottom belt 49 to be driven in timed relationship to the travel speed for the fold fingers 37 and the side belts 45.

During transfer of the folded diapers 17 from the takeoff carrier 43 to the accumulator 51, the diapers are guided by a pair of stationary, bridging guides 227 (FIGS. 4 and 12) which engage the vertical sides 20 of the diaper legs 27 which are being conveyed rightward by the bottom belt 55 of the accumulator 51. Herein, the bridging guides 227 are in the form of vertical plates which are disposed between the takeoff conveyor side belts 45 and the accumulator side belts 53. More specifically, the bridging guides are secured in adjusted positions by horizontally disposed studs 229 (FIG. 12) which extend to an upstanding leg of an angle shaped bracket 231 fixed to the horizontal support 167.

To assure that the diapers 17 are continuously driven forwardly as they transfer between the takeoff conveyor 43 and the accumulator 51, the bottom belt 55 of the accumulator has its input end projecting leftwardly into the discharge ends of the side belts 45 of the takeoff conveyor, as best seen in FIGS. 1 and 4. At this end, the bottom belt 55 is wrapped about a horizontally disposed roll 233 (FIG. 12) which is fastened to a support shaft 235 joumaled in suitable bearings in bearing mounts 237 fastened to the horizontal support 167. The bottom belt 55 is supported for generally horizontal movement by a dead plate 139 (FIG. 13) fastened to the inwardly directed flanges of angle shaped plates 241 which are fastened by suitable brackets to the supporting frame for the folding apparatus.

As can best be seen in FIGS. 1 and 4, the bottom belt 55 carries the diapers rightwardly to the accumulator side belts 53 and then into a pair of stationary side guides 243 (FIG. 1.5)

from which the now stacked diapers can be removed in predetermined quantities, for example, in groups of 12. The stationary side guides 243 are disposed to guide the vertical sides 28 of the folded diapers 17 and are fastened by suitable brackets 245 bolted to the horizontal portion of an inverted U- frame 247, as best seen in FIG. 15, which is supported by suitable brackets on the frame of the folder-stacker apparatus.

The diapers are collected and abutted at a fourth or accumulating station within the

belts

53 and 55 which are driven at a speed which is considerably slower than the speed of the

belts

45 and 49 of the takeoff conveyor 43. Thus, the spaced, faster moving diapers will abut one another in the accumulator 51. The accumulator bottom belt 55 is driven during its return run by reversing the belt 55 about a first idler 249 (FIG. 1) and then forming a loop about a driving roll 251 (FIG. 1) before continuing to the left on the return run to the idler roll 233 at its input end. The driving roll 251 (FIG. is fixed to a shaft 253 extending between and joumaled in bearings on supporting plates 255 of the frame 247. On an end of the shaft 253 is fixed a sheave 257 driven by a belt 259 which extends downwardly to a sheave 261 (FIGS. 1 and 5) on a jack shaft 263 joumaled in a bearing mounted in a bracket 265 fastened to the frame base 73 (FIG. 5). The jack shaft 263 is disposed generally horizontally and carries at one end a sheave 267 driven by a belt 269 which extends leftwardly, as viewed in FIGS. 1 and 5, to a sheave 271 of a gear reducer unit 273 which is driven by the jack shaft 191 which has been previously described as a portion of the drive for the side belts 45 of the takeoff conveyor 43. The gear reducer unit 273 causes considerable reduction in the speed of the accumulator belt 55 relative to the takeoff conveyor belts whereby the diapers become abutted within the accumulator 51 with their faces 47 disposed together as seen in FIG. 16.

The accumulator side belts 53 engage the vertical sides 28 of the folded diapers and hold them as they accumulate in a stack which continuously moves rightward. These side belts 53, as viewed in FIG. 4, are guided by dead plates 275 (FIGS. 4 and 13) extending between and closely adjacent to vertically disposed

rolls

277 and 279. The dead plates 275 are supported by horizontally extending studs 281 (FIG. 13) fastened at an adjusted position to vertically disposed legs of the angle plates 241. The side belts 53 move rightward from the vertically disposed idler rolls 277 joumaled on upstanding shafts 283 (FIG. 1 & 12) fastened to the horizontal support 167. To tension the belts 53, the idler rolls 285 (FIG. 14) are joumaled on upstanding posts 287 fixed at lower ends to crank arms 289 adjustably mounted on a horizontal plate 291 spanning a pair of vertical frame legs 87.

As best seen in FIG. 14, the drive rolls 279 are knurled to provide the driving friction necessary to drive the side belts 53 wrapped about them. Supporting shafts 293 for the knurled drive rolls are disposed vertically and are rotatably supported in upper bearings 295 on the horizontal plate 291 and in lower bearings 297 fastened to the base plate 73. Driving sheaves 299 are fastened to the support shafts 293 and a driving belt 301, as best seen in FIGS. 5 and 14, extends from these sheaves 299 about an idler pulley 303 mounted on a post 305 carried by a crank 307 to keep the driving belt 301 tight. The driving belt 301 is driven by a sheave 309 (FIG. 5) which is driven through a right angle geared unit 31] (FIGS. 5 and 14) which, in turn, is driven by the jack shaft 263 which has been previously described as driving the accumulator bottom belt 55. In this manner, both the side belts 53 and the bottom belt 55 may be driven at the same slower speed relative to the takeoff conveyor belts to make sure that the diapers accumulate prior to moving rightward into the discharge guide plates 243 from which they are removed either automatically or manually in groups having a predetermined number of diapers therein.

To facilitate an understanding of the operation of the apparatus and the method of folding the diapers, a brief description of the apparatus will now be given. The incoming diapers 17 are disposed flat in an endwise succession one behind the other and spaced from each other on the upper surface of the conveyor belt 33. They are moved, as viewed in FIGS. 1 and 16, to the left end of the conveyor 31 at the roll 59 at which the belt 33 reverses its direction of movement. At the left end of the conveyor 31, the leading edge of the diaper abuts and is guided downward by the curved plate 72 as it moves with the belt 33 in an arcuate path about the roll 59 and at belt speed. When the leading diaper end reaches the bottom edge of the curved plate 72, inertia and gravity carry the leading edge downward and rightward to strike a downwardly extending curved plate 312.

As the midpoint of the diaper leaves the curved chute 35, opposed folding fingers 37 carried 'by chains 99 abut the diaper at the location of the tack embosses 23 and hold the diaper at this midpoint against the belt 33 as it moves rightward along its lower horizontal run. The fingers 37 move through but a short distance before they move into a slot defined between the overhead belt 33 and the forming plate 41. The curved portion 93 of the forming plate 41 guides the diaper legs 27 as they trail the fingers 37 upward into the slot. The diaper thereby becomes folded and the legs 27 are compressed against each other. The compression is sufficient to form a definite fold 29 between the legs at the fingers 37. When the fingers 37 withdraw the diaper legs 27 completely from the former 39, the diaper legs pivot under the action of gravity downward about the fingers 37 until the bottom edges 21 engage the upper surface of the bottom belt 49 of the takeoff conveyor 43. The outer ends of the fold fingers are held by the bars from pivoting about the connections to the chains 99 and, as the diaper travels rightward, the fold fingers gradually retract from the fold. The diaper is now folded and vertically disposed with the fold 29 on top as it moves into the converging mouth being defined by the side belts 45 which center the diaper on the centerline 101 between them. As the side belts engage the diaper sides 28, the fingers 37 withdraw from the fold 29. The diaper is then wholly supported vertically, along its sides by the side belts 45 and at its ends 21 by the bottom belt 49. The fold fingers 37 continue to travel to the right to sprockets 103 and then begin their return move ment.

While within the takeoff conveyor 43, the folded diapers 17 are spaced from one another by the distance between diaper centers on the belt 33. Just prior to leaving the takeoff conveyor side belts 45, the ends 21 of the diapers move into engagement with the bottom belt 55 of the accumulator 51 which gives them a continued forward impetus through very short, bridging guides 227 to the accumulator side belts 53 which are generally aligned with the side belts 45 for the takeoff conveyor 43. During the transfer of a diaper to the accumulating conveyor, the side edges of the diaper are briefly engaged by the side belts 45 which are traveling at higher speed than the bottom belt engaging the lower ends of the diaper. However, the side edges of the diaper are soon being retarded by the stationary guides 227 while the bottom belt is still moving forwardly. This transfer occurs relatively quickly and over a small space. Also, the inertia of the diaper precludes instantaneous changes of speed with the result that the diaper transfers quite readily into the accumulating conveyor while still retaining its vertical disposition.

In the accumulator 51, the diapers 17 are engaged on the vertical sides 28 and on the lower ends 21 by belts which are moving at the same speed to the right as viewed in these FIGS., but much slower than the belts of the takeoff conveyor 43. The accumulator side belts 53 and bottom belt 55 are driven at a predetermined, but sufficiently slow speed that each incoming diaper abuts its preceding diaper and travels rightward a distance about equal to its thickness before being abutted by a following diaper. As the speeds of the conveyors can be readily adjusted, a desired ratio between their speeds can be maintained so that diapers accumulate relatively uniformly as diagrammatically illustrated in FIG. 16. The diapers are carried forwardly in a row or stack from the accumulator 51 into a discharge section defined by the pair of stationary side plates 243 which guide the edges of the diaper (FIGS. 1 and as the bottom belt 55 for the accumulator continues to move rightward. A predetermined number of diapers, usually 12, may then be removed manually or automatically by machinery for subsequent compression and packaging operations.

In the event of jamming of diapers l7 somewhere in the folder-stacker apparatus, there may be provided an automatically operated bypass mechanism which will allow incoming diapers to bypass the folder-stacker apparatus. For this purpose, the line shaft 147 may be provided with an overload torque sensor 330 (FIG. 15) which will sense an overload torque condition on the line shaft 147. Such overloads may be caused by a jamming of diapers somewhere within the apparatus. The overload torque sensor 330 operates an electrical switch which in turn operates a fluid cylinder 331 (FIG. 1) fastened to a bracket 333 on the side frame 65 to retract an operating piston and rod 335 which is connected at its free end to a crank arm 337. The crank arm is pivoted on a shaft 339 which pivotally mounts the curved plate 72. The operation of the cylinder 331 causes the crank arm 337 to pivot the shaft 339 and curved plate 72 which moves to an inoperative position such as shown in dotted lines in FIG. 16. In this retracted position the curved plate is high above the belt 33 and is no longer effective to cause the diaper to follow the belt.

33 about the roll 59. Another takeofi' conveyor 341 (FIG. 16) may be disposed adjacent the curved guide chute 35 so that when the guide plate 72 is in its retracted position, the incoming diapers 17 may continue to feed leftward onto the conveyor 341. At the same time, the signal from the overload sensor may be used to shut down the folder-stacker apparatus to permit repair of the difficulty.

It will be seen from the foregoing that the folding and stacking apparatus is capable of operating at relatively high speed and of accurately folding flexible articles such as diapers in a continuous and automatic manner. The apparatus has been found to fold with relative ease articles which could be easily tom. The apparatus may be operated for relatively long periods of time with little or no maintenance.

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.

We claim:

ll. In an apparatus for folding flexible articles, an endless conveyor for advancing a series of said articles resting thereon and having their centers spaced apart a predetermined distance along a first predetermined path to one end of said conveyor where said conveyor is inverted, guidemeans at said one end of said conveyor to constrain the leading end of each article to follow a curved path to the exit of said guide means, said leading end of said article being free to depend downwardly from the exit of said guide means, finger means including at least one finger to engage the depending article substantially medially and hold it against the inverted conveyor to travel with the conveyor along a second predetermined path, means to form a fold at the location of said finger, takeup means to receive said folded articles, and means for retracting said fingers from said folds of the articles upon their delivery to said takeup means.

2. An apparatus'fin accordance with claim 1 in which said takeup means is atakeup conveyor for carrying said articles at a first speed, and in which an accumulating conveyor follow- :ng said receiving conveyor is aligned with the path of travel of aid articles while on said take up conveyor, said accumulating :onveyor traveling at a speed sufficiently slower than the \peed of said takeup conveyor so incoming folded articles are ibutted with preceding articles in the accumulating conveyor vhereby the articles are abutted and form a stack.

3. An apparatus in accordance with claim 11 in which said inger means includes a pair of endless bands each carrying a plurality of fingers about an endless path, each of said fingers on one band being aligned with a finger on the opposite band for simultaneously engaging and advancing a respective article, and said means for retracting includes guides for directing said bands in paths diverging from each other to withdraw the fingers automatically from the folded article and thereby deposit the article in said takeup means.

4. An apparatus in accordance with claim I in which said fingers travel on a substantially horizontal plane when folding the article and in which the means for folding the article directs said end portions into a substantially horizontal plane when forming said fold and in which said article is free to pivot downwardly about a finger to dispose the folded article substantially vertically before it is deposited in said takeup means.

5. An apparatus in accordance with claim 2 in which said takeup and accumulating conveyors include means to engage the sides of the folded articles and hold them upright as they are conveyed by said conveyors.

6. An apparatus in accordance with claim 5 in which each of said side engaging means includes opposed endless bands for engaging the opposite sides of the upright articles and in which said conveyors have a bottom conveyor belt for supporting and conveying the lower ends of the articles.

7. In an apparatus for folding articles such as a disposable diaper, an endless conveyor conveying diapers to one end thereof, means defining a curved chute adjacent said conveyor end to guide the leading end of each diaper to travel in an arcuate path around said conveyor end, means including endless bands each carrying a series of spaced fold fingers along predetermined paths to engage a diaper substantially centrally thereof as the diaper exits from said curved chute and to advance the diaper in the direction of finger travel, forming means disposed along said path of finger travel to force the extremities of said diaper together and thereby form a fold at said finger, said diapers being thereafter free to pivot about said finger to orient said legs of said diaper downwardly, means for automatically withdrawing said finger from said fold, and conveyor means operable when said finger withdraws to hold said folded diaper upright and convey it away.

8. The method of folding and stacking a series of flexible articles comprising the steps of advancing said unfolded articles successively along a predetermined path at regular intervals, engaging each article substantially centrally by at least one finger while leaving the ends thereof free, forcing the free ends of said article together to form a fold in said article at said finger, withdrawing said finger to release said article therefrom, and abutting successive folded articles and holding the sides thereof with the articles being disposed in an upright position and in a column to form a stack of folded articles.

9. A method in accordance with claim 8 in which each of said folded articles are abutted in a stack by conveying said folded articles at a given speed into an accumulator traveling at a speed which is substantially slower than said given speed so that each of the articles incoming to the accumulator abuts a preceding article.

10. A method in accordance with claim 8 in which flat unfolded articles are moved in a first direction to the exit end of a conveyor and are constrained to travel in an arcuate path about the exit end of the conveyor, whereupon the leading portion of the article is released for engagement of a succeeding portion by said finger.

11. The method of folding and stacking a series of flexible flat articles comprising the steps of advancing the unfolded articles at a first predetermined speed successively along a first predetermined path at regular intervals to a first station, at said first station engaging a predetermined portion of each of said articles successively with at least one finger while leaving the ends thereof free, by said finger advancing each article along a second predetermined path at said predetennined speed past a second station to a third station, at said second station folding the articles about the respective fingers, disposing the respective folded articles vertically dependent from said fingers between said second and third stations, at said third station engaging the edges of the folded articles, thereupon withdrawing the fingers from the respective articles, earrying the engaged folded articles at the same predetermined speed to a fourth station, and at said fourth station abutting successive folded articles in a stack.

12. In an apparatus for folding articles, means for advancing said articles in succession at regular intervals along a first predetermined path, finger means including fingers moving along an endless second predetermined path to catch a predetermined portion of each of said articles successively and advance the articles along at least a portion of said second predetermined path. a former disposed along said second predetermined path for folding said article at said finger, a takeup conveyor disposed along said second predetermined path for receiving said folded articles and moving them in a third predetermined path, and means for retracting said fingers from said articles after their delivery to said takeup conveyor, said finger means including a pair of endless bands each carrying a plurality of fingers, each finger on one band being aligned with a finger on the other band to engage the article substantially simultaneously with its aligned finger, and said means for retracting including means for carrying said hands with said fingers thereon along diverging paths so that the finers automatically withdraw to release the folded article.

13. In an apparatus for folding articles, means for advancing said articles in succession at regular intervals along a first predetermined path, finger means including fingers moving along an endless second predetermined path to catch a predetermined portion of each of said articles successively and advance the articles along at least a portion of said second predetermined path, a former disposed along said second predetermined path for folding said article at said finger, a takeup conveyor disposed along said second predetermined path for receiving said folded articles and moving them in a third predetermined path, and means for retracting said fingers from said articles after their delivery to said takeup conveyor, said takeup conveyor including means for engaging opposite sides of the folded articles and holding them upright.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3 572 639 Dated Match 30 J 911 Inventor(s) James A. Murghy, Charles A. Lee, Warren R. Furbec and Philip G. Day It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 4, line 3, before "legs" insert -channels 85 which,

in turn, are fastened to frame-;

Column 6, line 69 change "139" to -239;

Column 9, line 75, change "inger" to finger-.

Signed and sealed this 20th day of July 1971.

(SEAL) Attest:

EDJARD M.FLETCHEH,JR. Attesting Offi r WILLIAM E. SCHUYLER, J1 Commissioner of Patent:

PAH HA unzn nnzcn

Claims

1. In an apparatus for folding flexible articles, an endless conveyor for advancing a series of said articles resting thereon and having their centers spaced apart a predetermined distance along a first predetermined path to one end of said conveyor where said conveyor is inverted, guide means at said one end of said conveyor to constrain the leading end of each article to follow a curved path to the exit of said guide means, said leading end of said article being free to depend downwardly from the exit of said guide means, finger means including at least one finger to engage the depending article substantially medially and hold it against the inverted conveyor to travel with the conveyor along a second predetermined path, means to form a fold at the location of said finger, takeup means to receive said folded articles, and means for retracting said fingers from said folds of the articles upon their delivery to said takeup means.

2. An apparatus in accordance with claim 1 in which said takeup means is a takeup conveyor for carrying said articles at a first speed, and in which an accumulating conveyor following said receiving conveyor is aligned with the path of travel of said articles while on said take up conveyor, said accumulating conveyor traveling at a speed sufficiently slower than the speed of said takeup conveyor so incoming folded articles are abutted with preceding articles in the accumulating conveyor whereby the articles are abutted and form a stack.

3. An apparatus in accordance with claim 1 in which said finger means includes a pair of endless bands each carrying a plurality of fingers about an endless path, each of said fingers on one band being aligned with a finger on the opposite band for simultaneously engagIng and advancing a respective article, and said means for retracting includes guides for directing said bands in paths diverging from each other to withdraw the fingers automatically from the folded article and thereby deposit the article in said takeup means.

4. An apparatus in accordance with claim 1 in which said fingers travel on a substantially horizontal plane when folding the article and in which the means for folding the article directs said end portions into a substantially horizontal plane when forming said fold and in which said article is free to pivot downwardly about a finger to dispose the folded article substantially vertically before it is deposited in said takeup means.

11. The method of folding and stacking a series of flexible flat articles comprising the steps of advancing the unfolded articles at a first predetermined speed successively along a first predetermined path at regular intervals to a first station, at said first station engaging a predetermined portion of each of said articles successively with at least one finger while leaving the ends thereof free, by said finger advancing each article along a second predetermined path at said predetermined speed past a second station to a third station, at said second station folding the articles about the respective fingers, disposing the respective folded articles vertically dependent from said fingers between said second and third stations, at said third station engaging the edges of the folded articles, thereupon withdrawing the fingers from the respective articles, carrying the engaged folded articles at the same predetermined speed to a fourth station, and at said fourth station abutting successive folded articles in a stack.

12. In an apparatus for folding articles, means for advancing said articles in succession at regular intervals along a first predetermined path, finger means including fingers moving along an endless second predetermined path to catch a predetermined portion of each of said articles successively and advance the articles along at least a portion of said second predetermined path, a former disposed along said second predetermined path for folding said article at said finger, a takeup conveyor disposed along said second predetermined path for receiving said folded articles and moving them in a third predetermined path, and means for retracting said fingers from said articles after their delivery to said takeup conveyor, said finger means including a pair of endless bands each carrying a plurality of fingers, each finger on one band being aligned with a finger on the other band to engage the article substantially simultaneously with its aligned finger, and said means for retracting including means for carrying said bands with said fingers thereon along diverging paths so that the finers automatically withdraw to release the folded article.