US 3513628 A
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Description (OCR text may contain errors)
c. A. LEE ETA!- ARTICLE COMPRESSING APPARATUS May 26, 1970 3 Sheets-Sheet 1 Filed Aug. 22, 1967 May 26, 1970 c. A. LEE E ARTICLE COMPRESSING APPARATUS 3 Sheets-Sheet 2 Filed Aug. 22. 1967 United States Patent Filed Aug. 22, 1967, Ser. No. 662,404 Int. Cl. B651) 1/20, 13/20, 63/02 U.S. Cl. 53124 14 Claims ABSTRACT OF THE DISCLOSURE An article or a stack of articles, such as disposable diapers, are compressed between a pair of converging endless belts which discharge the article into a holder. The latter may be a pair of spaced jaws which hold the article compressed as a wrapper is disposed about the article to hold the same in a compressed state. To provide sufiicient force to overcome resistance of the movement of an article into the holder without tearing or scufiing the same, the belts act through a succeeding article which is abutted against the article being discharged to push the latter into the holder. A stream of abutted articles may be maintained within the belts by running an article input carrier to the belts at a speed faster than the belt speed and by using a slip clutch drive for the input carrier to prevent overrunning or jamming of articles as they are abutted.
This invention relates to an apparatus for compressing articles such as, for example, cellulosic pads, creped tissues, and disposable diapers, as they move continuously along a predetermined path of travel. More particularly, it relates to compressing a stack of such articles and the packaging of the compressed stack.
Disposable diapers as produced in large quantities on high-speed production lines are relatively thick and bulky. It is preferred to reduce the bulk of the articles by compressing the same to eliminate much of the air space between plies and thereby facilitate their handling, storage and transportation. Also, it is particularly advantageous to compress a stack of diapers to a uniform size facilitating packaging of the diapers and concomitantly reducing the amount of material employed for the package. For instance, a dozen or more folded disposable diapers are compressed to about one-half their original, uncompressed height and are then held against expansion by an encompassing band or packaging container. The pack aged diapers have an improved appearance and will expand slightly when removed from their packaging.
Stacks of diapers vary in height due to their size and moisture and fiber content and often exceed eight or more inches in height before compression. Compression should be effected without materially decreasing the absorptivity of the diapers or scufiing, tearing or otherwise injuring the product.
It is known to employ traveling platens or nip rollers to compress facial tissues. Also U.S. Pat. No. 2,413,556 discloses apparatus for compressing cellulosic pads between a pair of endless belts; however, such apparatus is not usable in compressing articles moving in a steady stream at relatively high production rates. A need exists for apparatus for efficiently compressing a continuous stream of articles such as diapers, without injuring them, and for moving the diapers into and through a packaging station at which they may be encompassed by a band or sleeve to hold the articles in a compressed state.
Accordingly, a general object of the invention is to provide an apparatus for compressing articles, such as dis- 3,513,628 Patented May 26, 1970 posable diapers, in a highrspeed and economical manner.
A more specific object of the invention is to compress a steady and continuous stream of articles and to move them into a station for receiving an encompassing band or package to retain the articles in a compressed state.
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. 1 is a side elevational view of an apparatus for compressing articles and embodying the novel features of the invention;
FIG. 2 illustrates a bundle of diapers which have been compressed and banded with the apparatus of FIG. 1;
FIG. 3 is a partial plan view of the apparatus of FIG. 1;
FIG. 4 is a horizontal sectional view taken along the line 44 of FIG. 1 to illustrate the drive mechanism for the apparatus of FIG. 1;
FIG. 5 is an enlarged, fragmentary sectional view taken along the line 5--5 of FIG. 1;
FIG. 6 is a vertical sectional view taken substantially along the line 6-6 of FIG. 5;
FIG. 7 is a vertical sectional view taken along the line 77 of FIG. 5; and
FIG. 8 is a perspective view of a mounting bracket as used in the apparatus as shown in FIGS. 5 and 6.
As shown in the drawings for purpose of illustration, the invention is embodied in an apparatus which, very generally, includes an input conveyor 11 for supplying and moving continuous streams of articles, such as stacks 13 of diapers, from right to left in FIGS. 1, 3 and 5, into a space between compression belts 15 (FIGS. 3 and 5) which engage opposite faces of the stack and compress the stack as they carry it forward to a discharge station. In this instance, the belts discharge the compressed article into the space between a pair of opposed holders in the form of jaws or duck bills 17 about which may be placed a band 19 or alternatively a packaging container (not shown). The compressed article and band are slid to the left and thereby removed from the duck bills 17, whereupon the compressed article will expand to the extent permitted by the encompassing band 19. Although the apparatus may be employed for compressing various articles or groups of articles, the present invention is described hereinafter in connection with the compressing of a plurality of disposable diapers, usually 4 to 12 diapers. In this instance, as the diapers travel through the machine, they are disposed in the following manner. The diapers are folded in half and are disposed on edge with their flat sides 20 (FIG. 2) disposed vertically and abutted against the flat side of an adjacent diaper to form an on-edge stack, hereinafter referred to simply as a stack of diapers.
Disposable diapers are produced at high rates of speed, and it is desirable that they be compressed and banded also at a high rate of speed, preferably in a continuous or a substantially continuous process. To this end, the present invention contemplates a series of stacks 13 of diapers moving continuously from the input conveyor 11 through the belts 15 and duck bills 17. In this instance, the stacks of disposable diapers are compressed to about one-half of their original thickness between their outermost fiat sides 20 as they are discharged from the compressing belts, and the diapers will spring back to about two-thirds of their original thickness when the bands are removed by the consumer.
As will be explained in greater detail, it is a particularly difiicult problem to move the diaper stack into and through the duck bills without scufiing or tearing the outermost sheets of the diaper stack. More particularly, the stack being discharged meets with resistance resulting from frictional forces between its sides and the engaged surfaces of the duck bills. The resistance force to forward movement of the diaper stacks will hold a stack at the discharge end of the conveyor belts which will then slip across the faces of the stationary stack and scuff or tear the same. In accordance with the present invention, a diaper stack is moved continuously through and ejected from the compressor belts 15 into the duck bills, by a cumulative pushing force derived from a full stream of abutted diaper stacks between the belts. To assure such a cumulative force, the input conveyor 11 is operated at a faster speed than the compression belts 15 to maintain the full stream of diapers disposed end to end (FIG. between the compression belts 15. To prevent overrunning and jamming of diapers at the discharge end of the input conveyor, while assuring a steady stream of abutted stacks of diapers in the compression belts, the input conveyor 11 is driven by a driving means including a controlled torque device, which slows movement of the input conveyor when the compresor belts are filled with diaper stacks and are preventing the entry of another stack into the belts, as will be explained in detail hereinafter. In this instance, the controlled torque device is in the form of a slip clutch 21 (FIG. 4) which slips when there is no room in the belts for another stack.
Referring now to the apparatus in detail, the diaper stacks travel along a generally horizontal plane on the input conveyor 11 which is in the form of a horizontally disposed, endless belt 23 having a plurality of slats 25 fixed at spaced intervals to the outer surface of the belt. Each of the slats is adapted to engage the upstream end of a stack of diapers and drive the stack in a positive manner to the conveyors discharge end which is at a drive roller 27 for the belt 23. The roller 27 is disposed closely adjacent to the inlet mouth or opening 28 (FIG. 3) between the compression belts 15.
While traveling along with the input conveyor 11, the diaper stacks 13 are guided between a pair of vertically disposed, side edge guides 29 (FIGS. 3 and 5) extending longitudinally along the opposite sides of the belt 23 and converging inwardly upstream to center the diaper stacks as they discharge into the inlet opening 28 between the compression belts 15. The side edge guides 29 are secured to opposite spaced, horizontal frame members 33 which, in turn, are supported by vertically depending legs 35. The input conveyor 11 is driven at a speed sufficiently faster than the speed of the compression belts 15 that there is a continuous and steady stream of diaper stacks 13 along the full length of the run of the compression belts. To drive the endless input conveyor belt 23, its
,drive roller 27 is journaled for rotation in the frame members 33 by a supporting shaft 37 which has a sprocket 39 fixed to one end. An endless drive chain 41 is trained about the sprocket and extends downwardly and forwardly to a sprocket 43 (FIGS. 1 and 4) fixed on a horizontally disposed shaft 45 (FIG. 4). The latter is fixed to the output side of the slip clutch 21 which is driven by a motor 47 (FIG. 4) through a series of belts and speed control devices as will be described hereinafter.
When the compressor belts 15 are completely filled with stacks of diapers and the conveyor belt 23 is attempting to push another diaper stack into the space between the belts 15, two opposing friction faces 49 and 51 (FIG. 4) on the slip clutch 21 will slip relative to one another so long as the input conveyor 11 requires a greater amount of torque to move forwardly at its usual speed than the predetermined amount of torque at which the friction faces begin to slide. Preferably, the friction faces are urged together by an adjustable spring so that the predetermined amount of torque at which the faces slip can be varied as desired. The driven side of the slip clutch 21 is fastened to an axially aligned shaft 53 journaled in a mounting bracket 55. The input side of the slip clutch 21 is driven through a commercially available variable speed control unit 57 (FIG. 4) by which the speed of the clutch input shaft 53 can be varied. By varying the speed of the latter, the speed of the infeed conveyor 11 can be adjusted relative to the speed of the compression belts 15 to avoid an excessive number of slipping operations at the slip clutch 21 when diaper stacks are being furnished to the compression belts 15 at a faster rate than the compression belts can compress them. The variable speed unit 57 is driven by an endless belt 59 trained about a sheave 61, which is fixed to a rotatable shaft 63. The latter carries a sheave 65 driven by a belt 67 extending to an adjustable split sheave 69 fastened to the shaft of the motor 47. To vary the speed of the belt 67, it is preferred that the sheave 69 be split so that its effective diameter can be changed by changing the position of the motor 47. The position of the motor 47 can be changed by turning a threaded adjusting screw 71 in a stationary nut on a motor support slide 73.
As the diaper stacks 13 leave the input conveyor belt 23, they move across a slight gap to a horizontally disposed bottom plate 73 (FIG. 3) extending beneath and along substantially the full length of the compression belts 15. This bottom plate 73 supports the bottom edges of the stacks 13 during compression; and to facilitate the smooth transfer of the stacks from the input conveyor to the compression belts, a leading end 75 on the bottom plate 73 is curved downwardly. Thus, the diaper stacks slide on the bottom plate into the nip between idler rollers 77 about which are trained the respective endless belts 15.
To compress the diaper stacks, the inner runs of the endless belts 15 are disposed to converge toward one another to reduce the space between the belts by about 50% from the wide inlet opening 28 to the narrow outlet opening 78 (FIG. 3). In the present instance, the belts move along a relatively straight line and uniformly converge along their inner runs relative to the longitudinal centerline of the bottom plate 73. For this purpose, the belts 15 are held against flexing and are guided along their inner surfaces by vertically disposed, dead plates 79 which extend tangentially from a position adjacent the idler rollers 77 to tangentially adjacent the driving rollers 80 located at the discharge ends of the belts 15. As the latter move along their return runs, they are directed and guided by upper and lower grooved rollers 81 which engage the top and bottom edges of the belt. These guide rollers are carried on support brackets 83 fixed to upper and lower, horizontally disposed, frame plates 85 and 87, respectively. Brackets 88 (FIG. 7) are fastened to the underside of the upper frame plate 87 and extend down to support the outer sides of the dead plates 79. A suitable belt tension roller 89 is journaled on a vertically disposed shaft 91 (FIG. 1) carried on crank arms 93 which can be pivoted and locked in position relative to the supporting plates 85 and 87 to hold the belts suitably tensioned.
To support the main upper and lower horizontally disposed plates 85 and 87, spaced vertical support stands 97 and 99 are provided. Each stand is formed with a pair of vertical legs 101 and an overhead cross beam 103, and also a lower cross beam 105. The upper plates 85 are fastened to the undersides of the cross beams 103 to converge toward each other at the discharge ends of the belts 15, and in a like manner, the pair of lower cross beams 105 support the lower plates 87, which are disposed beneath the top plates and also converge from the inlet ends to the discharge ends of the belts 15. These upper and bottom plates carry bearing assemblies for journaling the opposite ends of rotatable roller shafts 107 and 109 on which are fastened the respective idler and driving rollers. Upstanding studs 110 (FIG. 7) are fastened to the lower cross beams 105 to hold the bottom plate 73 substantially horizontal and at the proper height relative to the belts 15.
To drive the compression belts 15, the lower ends of the drive roller shafts 109 carry horizontally disposed sprockets 111 (FIG. 1) which are driven by chains 113 and 115 extending generally horizontally to small sprockets 117 and 119 (FIG. 4), respectively. The smaller sprockets are fastened to the upper ends of output shafts of gear reducer drives 121 and 123 which are driven by the shaft 63 to which is afiixed the sheave 65. The latter is driven by the belt 67 which extends to the driving motor 47 which is common to both the input conveyor 11 and the compressor belts 15. The speed of the compression belts usually ranges between 60 feet per minute and 70 feet per minute, and this speed can be adjusted by moving the motor 47 to change the effective diameter of the drive motor sheave 69. The speed of the input conveyor 11 can be then finely adjusted by the speed control unit 57 until the desired flow rate of "diaper stacks 13 along the input conveyor 11 is obtained.
The surfaces of the stack engaging the belt tear or scuif when the compressing belt slips relative to the surfaces. It is therefore important that the diaper stacks and belts move'at the same speed. As will be explained in greater detail below, if the diaper stacks are not abutted, the stack being discharged will not receive sufficient propelling force from the belts to overcome the frictional resistance of the duck bills, and the discharging stack will be held stationary while only partially inserted into the duck bills. When a stackfis held stationary, the belt surfaces sliding past the stationary stack 13 sculf and tear the outer sheets of the diaper stack. The outer sheets will ordinarily scuff quite readily, being made of creped tissue in the illustrated diape'n'although they could be of other materials. When, however, a discharging stack is abutted by a trailing stack 13, the belts exert through the trailing stack a forward push onthe discharging stack to move the same fully into the duck bills. Thus, there is neither slipping of the belt on the creped tissue nor any consequent scufling.
In accordance with another aspect of the invention, leading ends 125 (FIG. 5) of the duck bills 17 disposed adjacent the discharge ends of the belts are spaced apart by a greater distance than the spacing between the belts 15 at discharge outlet 78 so that the leading end of the discharging stack 13 may readily jump across a gap 127 which is the space between duck bills 17 and the belts 15. Usually, this space is about of an inch. Thus, the leading edges of the diaper may expand slightly as they move across the gaps 127 into the duck bills 17 without catching on the ends 125 of the duck bills. These duck bill ends 125 are spaced outwardly from tangential lines extending from;.the inner runs for the belts 15 to assure this expansion. Therefore, the leading edges of the outermost diaper will not snag or be cut by these duck bill ends as they leave the discharge outlet of the compressing belts 15.
To facilitate the slipping of a band about the outer free ends 129 of the duck bills, these free ends are toed inwardly toward one another. Stated differently, the free ends 129 of the duck bills 17 slightly converge toward each other at their free ends. It is preferred that the duck bills 17 be flexible so that a stack of diapers moving through the duck bills causes the outer ends to flex outwardly to a generally parallel relationship. When a stack 13 of diapers is removed, however, the duck bills return to theirtoed inwardly position. This flexibility is provided in the present invention by reducing the cross-sectional thickness of the duck bills towards the outer free ends. The duck bills 17' in this instance are in the foim of two flat, vertically disposed plates, but they may take various other shapes and still fall within the terms of the invention.
It is preferred to mount the duck bills 17 so that they can be readily adjusted to the proper position relative to the discharge ends of the belts at the rollers 80. For this purpose, the duck bills are provided with right angle molunting plates 131 fixed to the outer sides of the duck bills and extending outwardly to receive bolts 133 (FIGS. 5 and 6) to fasten the duck bills to upper and lower angle shaped mounting brackets 135. The upper horizontal walls of these brackets are provided with elongated, longitudinally extending slots 137 (FIG. 8) which receive bolts 139 (FIG. 6) for fastening to the upper and lower horizontal frame plates 85, respectively. By loosening the bolts 139, the duck bills 17 and the brackets 135 can be adjusted longitudinally relative to the plates and 87. Elongated, horizontally directed slots 141 (FIG. 8) are provided in the vertical wall of the mounting brackets 135 to permit movement of the duck bills 17 toward or away from each other and, after adjustment, the bolts 133 are tightened and locked in position.
In the preferred manner operation of the apparatus, diaper stacks 13 are produced at relatively high rates of production and are fed by the input conveyor 11 in a relatively continuous manner to the inlet opening 28 between the pair of compression belts 15. The compression belts 15 frictionally engage the stacks 13 and drive them to the discharge outlet 78 and thence between the duck bills 17. The duck bills hold the stacks frictionally and resist movement of the stacks therebetween. As a stack is nearly completely discharged from the compression belts, the force required to drive the stack through the duck bills may be greater than can be sustained by the part of the surface of the stack still in contact with the compression belts. The surface ordinarily would tear and scuff if the required force was not supplied from another source. In accordance with the present invention, the force is supplied by the compression belts through a succeeding stack firmly held therebetween. To this end the stacks are caused to abut one another at the discharge end of the compression belts.
If the stacks are to abut at their discharge ends of the compressing belts, it is necessary that they abut at the input ends of the compressing belts, i.e., before they engage the stacks, for after engagement, the stacks must move at belt speed, or there will be undesired slippage to cause damage of the stacks. Thus, each diaper stack must be abutted by a following stack as it travels throughout the compressing run, or it will stop at the discharge end of the belts until a succeeding stack reaches it and gives it a sufiicient push to leave the belts 15. To assure that each stack receives a push from a following stack and that the belts 15 do not slip relative to any of the stacks, the diaper stacks are abutted as they enter the belts and begin to be compressed thereby resulting in a stream of abutted stacks between the belts 15.
To assure a continuous and full stream of diaper stacks disposed end to end, i.e., abutted, and extending along the full compressing run of the belts 15 and to prevent an overrunning or jamming of diaper stacks on the input conveyor 11, the latter is driven at a faster speed than the speed of the compressing belts 15, and the forward motion of the input conveyor 11 is slowed when a full stream of abutted diapers extends from the inlet to the discharge ends of the belts 15. Clutch 21 slips until the compressed diaper stacks move forwardly whereupon the clutch re-engages and drives the input conveyor to deliver a new stack for compression.
The center of the diaper stacks 13 moves along a straight continuous line, and the outer sides of the stacks are compressed inwardly toward the center of the stack in a uniform manner. The diapers are held compressed during the banding operation. Also, the diapers are not permanently compressed to the maximum compression received or to the extent at which they are compressed when in the duck bills, as evidenced by the fact that the diapers expand again when unbanded even though this may occur at a much later date.
To assure that the compressed diaper stacks 13 move readily into the duck bills 17, the inner ends of the duck bills 17 adjacent the discharge ends of the compressing belts 15 are spaced farther apart and Outwardly from the inner runs of the belts 15. Thus, the leading ends of the diaper stacks 13 readily move across the gaps 127 and slide along the inner walls of the duck bills 17. The duck bills 17 are flexible and toed inwardly at their outer free ends 129 enabling a band 19 to be readily slipped over the duck bills prior to their free ends being flexed to a general parallel relationship by the diaper stacks moving through the duck bills. In this instance, the bands may be preformed and manually applied, but it is within the purview of the invention to automatically band, wrap or otherwise package the diaper stack. A stack of diapers has its edges disposed between the duck bills and extending beyond the edges of the duck bills to engage the inside of the band. As the stack travels forwardly, it carries the band forwardly. As a banded stack leaves the outer ends the diapers expand against the band.
With this apparatus it has been found possible to band a large number of diapers very efficiently and economically as compared to prior art apparatus. The diaper stacks are held by the bands to about 50% of their original height, and when subsequently unbanded, the diaper stack 13 recovers to about two-thirds its original height. correspondingly, the resulting diapers are relatively uniformly compressed and held to about /2 of their original height. The diapers have a better appearance and a uniform height which facilitates their being inserted into packages, boxes or containers. Considerable economies are realized in reducing the size and bulk of the containers in shipping, storage and handling costs as well as reducing the material requirements for the individual containers.
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 alternative constructions falling within the spirit and scope of the invention.
What is claimed is:
1. In an apparatus for compressing flat, compressible articles arranged parallel and face-to-face with one another in a given direction to form a stack, said articles having surfaces which are susceptible to tearing or scuffing, said apparatus comprising an article compression and conveying means including a pair of compression belts spaced apart on opposite sides of a path of movement for said stacks for compressing the stack only in the direction of stacking, each belt having a run converging toward a run of the other belt downstream of an inlet opening between said belt runs, said belts engaging the surf-aces of the first and last articles in said stack and conveying the article stacks forwardly along said path without slipping relative to said articles and thereby scufling or tearing the surfaces of the first and last articles in a stack, said 'belts conveying said article stacks to a discharge end of said conveying means, means including stationary walls defining a passageway through which said article stacks are pushed and discharged at said discharge end, said passageway defining means receiving and holding said article stacks in a compressed state and offering a resistance to passage of an article stack discharging from said belts, and means to feed article stacks to said inlet opening between belts at a speed faster than said belt speed and to abut each of the article stacks prior to compression with an immediately following article stack to assure that each compressed article stack receives a forward push from an immediately following article stack when being ejected from said compression belts to overcome the resistance of said stationary walls, thereby preventing tearing of the article by the slipping of the belts relative to the surfaces of the first and last articles in a stack spanning said stationary walls and said belts.
2. An apparatus in accordance with claim 1 in which said means to feed and to abut said article stacks includes an input carrier for feeding said article stacks to said compression belts, and further includes means to drive said input carrier at a speed sufliciently faster than the speed of said belt travel to assure that each article stack at said inlet end of said belts is abutted with a succeeding article stack whereby an entire stream of abutted article stacks is disposed from said inlet end to said discharge end.
3. In an apparatus for compressing articles moving along a predetermined path and having surfaces which are susceptible to tearing or scufiing, said apparatus comprising an article compression and conveying means including a pair of compression belts spaced apart on opposite sides of said path and each belt having a run converging toward a run of the other belt downstream of an inlet opening between said belt runs, said belts engaging the surfaces of the articles and conveying the articles forwardly along said path without slipping relative thereto and thereby scufling or tearing the surfaces, said belts conveying said articles to a discharge end of said conveying means, means defining a passageway through which said articles are discharged at said discharge end, said passageway defining means receiving and holding said articles in a compressed state and offering a resistance to passage of an article discharging from said belts, and means to abut each of the articles prior to compression with an immediately following article so that each compressed article receives a forward push from an immediately following article to overcome the resistance of said passageway defining means, thereby preventing tearing of the article by the slipping of the belts relative to the surfaces of the articles being discharged, said drive means including a slip clutch which slips and slows movement of the input carrier when an article being discharged therefrom abuts a preceding article.
4. An apparatus in accordance with claim 2 in which said stationary walls for receiving said articles and holding the articles in a compressed state are interior walls of a pair of spaced jaws which engage and hold surfaces of said article stacks as a wrapper is placed about the jaws, said wrapper encompassing said article stack to hold the same in a compressed state when the wrapper and its encompassed article stack are removed from said jaws.
5. In an apparatus for compressing fiat, compressible articles arranged parallel and face-to-face with one another in a given direction to form a stack, an input conveyor for conveying a stream of articles along said path, a pair of spaced apart compression belts downstream from said input conveyor to receive said article stacks between said belts at an inlet end adjacent the input conveyor, means to drive said belts at a predetermined speed to convey said article stacks along said path, said belts having runs in which the belts converge toward each other downstream of said inlet end to compress said article stacks only in the direction of stacking as the stacks are conveyed toward the discharge end of said belts, means including a pair of spaced plates at the belt discharge ends to receive and to hold said article stacks therebetween in a compressed state as said stacks issue from said compression belts, said plates being adapted to receive thereabout an encompassing wrapper for holding an article stack in a compressed state, means to drive said input conveyor at a speed faster than the predetermined speed of said compression belts to abut said article stacks and assure a full stream of abutted article stacks between said inlet and discharge ends of said belt so that the upstream article stacks exert a pushing force to discharge the article stacks from the belts between said plates without slippage between said belts and discharging article stacks, and means to limit the amount of longitudinally directed force exerted on said abutted stacks by said input conveyor thereby limiting forces tending to compress the stacks in the longitudinal direction.
6. In an apparatus for compresing articles moving along a predetermined path and having surfaces which are susceptible to tearing or scuffing, said apparatus comprising an article compression and conveying means including a pair of compression belts spaced apart on opposite sides of said path and each belt having a run converging toward a run of the other belt downstream of an inlet opening between said belt runs, said belts engaging the surfaces of the articles and conveying the articles forwardly along said path without slipping relative thereto and thereby scuffing or tearing the surfaces, said belts conveying said articles to a. discharge end of said conveying means, means defining a passageway through which said articles are discharged at said discharge end, said passageway defining means receiving and holding said articles in a compressed state and offering a resistance to passage of an article discharging from said belts, and means to abut each of the articles prior to compression with an immediately following article so that each compressed article receives a forward push from an immediately following article to overcome the resistance of said passageway defining means, thereby preventing tearing of the article by the slipping of the belts relative to the surfaces of the articles being discharged, said input conveyor drive means including a controlled torque device for abutting articles end-to-end within the compressing belts and thereby maintaining a full stream of articles within the belts.
'7. An apparatus in accordance with claim 6 in which said controlled torque device is a slip clutch which slips and slows movement of the input conveyor when an article on the input conveyor is held against faster forward movement by the articles disposed between the compression belts.
8. An apparatus in accordance with claim in which a motor is common to said driving means for said belts and said input conveyor.
9. An apparatus in accordance with claim 5 in which each of said plates has an end disposed adjacent a discharge end of one of said belts and spaced outwardly therefrom to define an enlarged space therebetween so that the leading ends of the articles may expand while moving into contact with the plates.
10. In an apparatus for compressing stacks of diapers as the stacks move along a longitudinally extending path to receive an encompassing wrapper, said machine comprising an input conveyor for conveying a series of stacks of diapers along said path, a pair of converging compression belts having an inlet end adjacent the discharge end of said input conveyor to receive said stacks of diapers between said compression belts, means including spaced rollers for supporting said compression belts for movement .along converging runs from said input conveyor to downstream discharge ends of said belts, a pair of stationary jaws downstream from said belt discharge ends to receive therebetween each stack of diapers as it issues from said compression belts and to receive thereabout an encompassing wrapper, means to drive said compression belts at a first speed, means to drive said input conveyor at a speed faster than said first speed to maintain a full stream of diaper stacks abutted end-to-end between the inlet and discharge ends of said compression belts whereby the upstream diaper stacks exert a pushing force to eject a diaper stack from the discharge ends of the belts and into the space between said jaws so that the belts do not slip relative to a stack and scuff it, said input drive means including a controlled torque device for limiting the speed of the input conveyor when said compression belts have a full stream of stacks abutted against one another and said input conveyor is delivering another stack to said belts.
11. An apparatus in accordance with claim 10 in which said jaws have inner ends disposed adjacent the discharge ends of said belts to receive the leading end of a diaper stack as it discharges from said belts, said inner ends being spaced outwardly of respective discharge ends of said belts.
12. An apparatus in accordance with claim 11 in which the outer ends of said jaws are toed inwardly and are flexible, said jaws being flexed apart with the movement of a diaper stack therebetween.
13. A machine in accordance with claim 10 in which said drive means for said input conveyor is adjustable to correlate the speed of the input conveyor to maintain a full stream of diaper stacks within the compression belts, and in which said control torque device comprises a slip clutch which is adjustable to slip at a predetermined torque.
14. In an apparatus for compressing fiat, compressible articles arranged parallel and face-to-face with one another in a given direction to form a stack and for holding the stack under compression during packaging, means for compressing article stacks including a pair of endless belts having converging runs spaced to engage first and last articles in the stack and to compress the stack only in the direction of stacking, a roller for each belt at the discharge end of each of said converging runs holding said belts at a predetermined spacing and causing a maximum compression of said article stack at said rollers, a pair of stationary holder plates having facing surfaces to hold the article stack under compression during packaging, and means mounting said holder plates adjacent said rollers with adjacent portions of said surfaces disposed outwardly of said converging belt runs to provide a spacing between said surfaces which is larger than said predetermined spacing whereby the leading ends of said first and last articles in the discharging stack are free to expand slightly while remaining under compression as said first and last articles move past said rollers and into the space between said plates.
References Cited UNITED STATES PATENTS 2,413,556 12/1946 Fourness et al. 53-24 2,907,447 10/1959 Ofi'utt et a1. 2,960,023 11/1960 Greiner et al. -15'2 3,138,164 6/1964 Respess 100-452 XR 3,254,472 6/ 1966 Clark et al. 53-259 3,319,394 5/1967 Talalay et al. 53259 XR PETER FELDMAN, Primary Examiner U.S. Cl. X.R.