CA1153027A - Apparatus for stacking imbricated articles - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

An improved newspaper stacking machine is described which features a pinch roller, pivoted for rotation up from beneath a stream of imbricated articles such as newspapers, pinching them against a stationary upper roller.
The machine features interrupter means for removing the stream of imbricated articles from conveyor belts carrying the papers through the machine, and an improved stacking device comprising a stacking gate, movable to permit a stack of papers to be conveyed to a binding location, and side and rear joggers so as to produce a more uniform and tighter stack. A microprocessor operates from a paper counter and a tachometer so that the machine operates in machine time, which is adjustable with reference to clock time.

Description

,3~'7 This invention relates to the field of stacking a stream of imbrica-ted articles into a regular neat stack. ~lore particularly~ the invention relates to the field of stacking a stream of newspapers into stacks of pre-determined size for binding and shipping to newspaper delivery personnel.
Those skilled in the field of delivery of newspapers will recognize that there are numerous technical problems which e~ist in the delivery of newspapers from a municipally located central press operation whicll may produce 25 to 40,000 papers per hour to the eventual consumer to wllom the individual papers are delivered. The steps connecting the press 1() witll the individual newspaper reader typically include stacking machinery for receiving an imbricated stream of folded newspapers from the press and for stacking the imbricated stream (i.e. a "shingled" stream, in which a front portion of each paper lies over or under the tail of the preceding paper in the stream~ into a substantially vertical stack which can then be bound up by wire, string or other means and delivered to a delivery location.
It is essential, of course that such stacks be as regular as possible to enable more ready handling and storage as well as to conserve space within the truck or other delivery vehicle in which the stacks are transported.
Too, it is desirable that the stacks be individually controllable with respect to the number of papers therein so that an individual delivery person can automatically receive a stack containing the number of papers subscribed to in his delivery region. Accordingly, it is an object of the invention to provide a newspaper stacker for receiving a stream of imbri-cated articles from a newspaper press or the like and for stacking these up in a neat and regular stack for ready binding of the stack by wire or string for delivery to a newspaper retailer, whether a person who delivers single papers to consumers or one who, for example, operates a newsstand and sells them one by one from such a stack.

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One difficulty in the stacking of ne~spapers from an imbricated stream arriving from a printer is that the major folds of the newspapers are not sharply creased and therefore the papers do not stack evenly. An improved newspaper creasing mechanism is disclosed.
It will be realized by those skilled in the art that the stacker is an inherently discontinuous mechanism, i.e. it receives a continuous stream of imbricated papers from a press and divides this continuous stream into a plurality of stacks. Disclosed herein is improved interrupter means for interrupting the flow of papers to the stacking area of the machine while not interfering with the continuous operation of the press.
As discussed above, it is desirable that the number of papers in each stack be individually controllable, and means for achieving this end is disclosed.
Another difficulty of the prior art is that sometimes the speed of the arrival of the imbricated stream of papers from a printing press varies over time. Accordingly, if the newspaper stacking machine is operated on the basis of real or clock time, sometimes the stacks of papers will not contain the predetermined numbers of papers desired. Accordingly, the stacking machine is operated in "machine time" -- that is, by sequencing the various operations of the machine by counting internally generated clock pulses, not relying on "real time", and accordingly always maintaining an accurate record of the location of a given paper in the machine at any given time, while permitting the speed of the machine to be varied.

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~153~7 Summary of the Invention The invention provides the method for stacking and creasing a stream of imbricated articles, said stream being generally horizontal and comprising articles having a major fold disposed generally transversely to the direction of travel o~ said stream comprising the steps of: creasing said articles by causing said stream to flow between opposed rollers having generally horizontal axes, the upper one of said rollers being rigidly mounted and the lower of said rollers being resiliently mounted;
and stac~ing said articles and interrupting said stream when a stack of said articles is completed to permit the conveying of said stac~ away from the stacking area.
The invention also provides in a method for stacking and compressing a stream of imbricated articles comprising the steps of: catching ones of said articles in stacking means, interrupting said stream when said stack is completed and compressing said articles prior to stacking said articles, the improvement which comprises: compressing said articles by passing said stream of articles between opposed rollers having generally horizontal a~es, the upper one of said rollers being rigidly mounted and the lower of said rollers being resiliently mounted, the lower of said rollers being pivotably mounted for engagement with said stream of articles upon energization thereof.
In the embodiment disclosed the movable roller is actuated to come into contact with the first paper of a stream so that there is no tendency for this first paper to jam between the rollers. The stream of creased papers is then passed between interrupter means adapted to interrupt the incoming stream and i3C~2~

delay it for a time sufficient to permit a completed stack of papers to be transported away from the stacking area to, e.g., binding machinery. The stream of papers then arrives at the stacking area where a plurality of vertical rods catch the incoming stream of papers. sack and side joggers are provided to make the stack regular and even. When the predetermined count of papers has been reached, the interrupter is actuated, the rods catching the papers are lowered away from the stream and the stack of papers is simultaneously lowered onto constantly-running conveyor belts conveying the stack of papers to a conveying area. During this operation, the interrupter means prevents the stream of papers from being ejected into the stacking area. The entire operation is microprocessor controlled and driven in machine time by tachogenerator means mounted on one of the rollers so that the microprocessor is always aware of where in the process the machine is at any given time. By providing positive connection between the various rollers and drive means which control the stream of papers, the speed of all these apparati are controlled at once and accordingly synchronization of the various machine operations by ~0 microprocessor control is possible. All the conveyor belts moving the papers through the machine run constantly; motion of the papers is controlled by control of the contact between the papers and the belts.
Brief Description of the Drawings An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

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Figure 1 represents an e~ternal side view of a newspaper stacker according to the invention;
Figure 2 represents a central cross-section parallel to the view of Figure 1 but centrally located within the machine;
Figure 3 is a schematic view showing the stacking operation, the chief function of the machine;
Figure 4 is a view showing the operation of the interrupter means and shows the manner in which the stack is transported away from the machine wllen it has been completed;
Figure 5 is a cross-sectional view taken along the line 5-5 of Figure 2 and shows details of the stacking area and jogger mechan;sms;
Figure 6 is a view taken along the line 6-6 of Figure S and shows further details of the jogger mechanisms; and Figure 7 is a block diagram schematic of the control arrangement.
Description of the Preferred Embodiment As discussed above, it is important to the proper function of the machine that its various component parts are individually controllable by a microprocessor and that the sequence of operations can be carefully controlled with respect to one another, without regard to ex~ernal "real"
~0 or "clock`' time. Accordingly, the various shafts and rollers which make up the conveying mechanisms of the machine are each coupled to one another by non-slip drive means, such as ordinary roller chains, and are all driven by the same drive motor. Therefore, the microprocessor can, by receiving a series of colmts from a tachometer driven by one of the shafts, be apprised of the position of a given paper - such as the last one of a given stack -within the machine. In turn, the newspapers themselves are transported by the machine by means of rubber belts running in metal rollers driven by these chains so that the lubricant necessary to ensure reasonable chain ~ 53~7 life does not dirty the papers. Figure 1 shows details of the chain drives used to synchronize the various shafts while Figure 2 shows the individual rubber belts used to actually transport the papers through the machines.
Simultaneous reference to these two Figures will show how the papers are driven through the machine according to the invention.
Thus, in Figure 1, a motor 10 is shown driving through a gear box 12 to power a chain 14 which in turn drives a first shaft 2. Shaft 2 drives a belt 30 whicll drives a movable roller 32. Concentrically mounted on shaft 2 ;s a second chain 16, which drives a stationary roller 36 mounted Oll shaft 9 used in conjunction with roller 32 to-pinch the papers, and a shaft 1 on wllich is mounted a roller used to drive the belt 30 transporting the papers through this area of the machine. A further chain 18, also driven by shaft 2, powers the belts which pull the papers through the central section of the machine and drives another chain 20. This drives shaft 6 which in turn drives yet another chain 23 which powers a gear box 22 which, by means of a drive shaft 2~, powers the jogger mechanisms indicated generally at 26 and which will be discussed in further detail below.
Various idlers not specifically called out are shown and are used, as is well-known in the art, to adjust the tension in the various chains. The chains shown in full in Figure 1 are outboard of the right side panel of the machine, while those in dotted outline are inboard thereof.
Pigure 2 shows a corresponding view of the belts used to power the papers through the system. It will be ~mderstood that due to the view chosen, singular belts are shown. As a rule, all the belts shown are at least duplicated across the middle of the machine, to ensure more regular transport of the papers. In a preferred embodiment these belts are Habasitt Co. Model RPG-20. Belt 30 is that first touched by the papers when they enter the machine, from the left in Pigure 2. This belt passes ~53~27 over the movable pinch roller 32 movable up and down by means of air bags 34 wllich are inflatable upon application of air pressure thereto, thus tllrusting the pinch roller 32, mounted on a pivoting arm 35, into substan-tial contact with the stationary roller 36 thus pinching the papers and tightly creasing their folds so as to provide a more regular stack. In a preferred embodiment these air bags are Firestone Model 131 "Airmounts"
(Trademark) and require typically 80 psig for operation. A second belt 40 is mounted above the paper stream at the pinch roller point so that sliding contact of the papers with the belts or the rollers is prevented, thus tending l~ to pull tllem more firmly through this portion of the machine~ A counter ~2 whicll may be a conventional star wheel co~mter such as that sold under the name EDS IDAB ~lodel 112C Newspaper Sensor can be used to individually count the papers. An infrared sensor 44, such as the Banner Company's Infrared Object Detector or other optical sensor may be provided at the left side of the machine to signal when the first paper of a stream arrives.
As discussed above, it is desirable that the lower movable pinch roller 32 not be in contact with the fixed pinch roller 36 except when papers are present therebetween, as the first paper of a stream if presented to a pair of close rollers tends to jam up. Accordingly, the sensing of a paper by the optical sensor 44 provides a signal which is controlled by a micro-pl~ocessor, located in a control housing 45 and discussed in further detail below~ to energize the air bags after a suitable delay so as to allow the leading edge of the first paper to enter between the pinch rollers 32 and 36.
After having been thus creased and counted, the papers then enter the interrupter area of the mechanism. The interrupter comprises two or more horizontally disposed bars 50 pivoted at one end on a pivot 52 for vertical lifting under the influence of an air cylinder 54. When energized, ~153~7 the air cylinder 54 closes upon itself (Figure 2) thus moving the inter-rupter bars 50 upwards between the conveyor belts 56 used to convey the papers through this area of the machine when interruption is not required.
lYhen the interrupter bars 50 are pivoted upward about pivot 52, the end of the interrupter bars 50 strike discs 58 which may be spring loaded as shol~n to lengthen their service life. The papers are thus removed from the contact of conveyor belt 56 and the paper stream temporarily stops.
Since papers continue to be incoming, the distance between similar points on each of the papers compresses while their flow is being interrupted, 1~ that is, they grow closer together. Optionally steel straps 81, shown in phantom, may be provided to ensure that the interrupted stream of papers does not buckle upwardly. The straps 81 may be mounted eccentrically on the discs 58, for adjustment of their tension. In the meantime, a previously formed stack of papers can be transported away. lVhen this has been done, the interrupter bars 50 drop back down again, the stream of papers again come into contact with conveyor belt 56 which is continually moving, and the process continues. The papers then are drawn into contact between belts 62 and 64, respectively, which fire the papers into the stacking area, which is at the extreme right side of the machine. The stacking area, indicated generally at 66, is defined by vertical stacker bars 68.
It is in this area that the papers are stacked. When the predetermined stack count has been reached, the stacker bars 68 drop down allowing the stack of papers to fall upon another conveyor belts 70 and 70a to be conveyed away from the stacking area for binding up for purposes of convenient transport and distribution.
Also in the stacking area 66 are back joggers indicated generally at 72 ~Yhich comprise moving plates 112, cam driven back and forth, which serve to gently push the stacked papers into a regular array or stack which ~ ~3~

is neat and takes up the minimum amount of space, which is clearly desirable when the stack of papers is being handled. Side joggers indicated generally at 26 perform a similar function for the sides of the stack being formed and are driven by a drive shaft 24 operating through a gear box 22 as indicated in Figure 1.
Reference will now be made to Figure 3, which shows the stacking operation under normal conditions (that is, when the stream is not being interrupted to permit conveying of a stack of papers away from the stacking area). Figure 4, by comparison, shows the operation of the machine not 1() ulldcr 5ucll conditions - that is, the stream being interrupted and a stack of papers being conveyed away from the stacking area. Therefore, comparison of these two figures will make clear many aspects of the inventive operation of the machine. In both Figures 3 and 4, the papers are indicated generally by "P" and are shown with their major fold forming their leading edge, this being atop the tail of at least the preceding paper to form the imbricated stream.
Regardless of whether the stream is being interrupted or not, the pinch operation is the same and is not interrupted by the interrupter means.
Accordingly, the belts 30 and 40, are in constant operation as are the

2~ other belts which drive the newspapers through the machine. By this continuous operation of the belts, it is not necessary to stop and start the motor during normal operation, nor to provide clutch means, thus grently lowering the mechanical loading of the various component parts, and lengthening their service life. Instead, the interrupting of the various operations which are driven by the belts is done by removing the newspapers from the areas of the belts so that they do not interact with the newspapers. This is, for example, what is done during the interruption operation when the pivoted lever arms 50 pick up the oncoming stream of 3d27 newspapers P away from the area of the belt 56 which ordinarily drives them through this region. This is shown in Figure 4 where it will be observed that the interrupter arms 50 are interposed between the belts 56, thus picking up the stream of newspapers P off the belts 56. A particular newspaper 82 is caught by its tail between the end of the interrupter bar 50 and a stationary disc 58. The other papers, being imbricated, tend to stack up behind the paper caught 82. The distance between the individual papers P naturally grows smaller and smaller with each incoming paper P.
Therefore, it is necessary that the period of interruption be as short as possible. This is done by means of the stacker mechanism which is shown in a first mode of operation, making a stack of papers in Figure 3, and in a second mode, the stack having been made being conveyed away in Figure 4.
Referring to Figure 3 it will be seen how opposing belts 62 and 64 driven by the chain 21 of Figure 1 operate on the upper and lower surfaces of the individual papers P to eject or "throw" them into the stacking area indicated generally at 66. They then impact the stacker bar 68 and settle to form the stack indicated generally at 90. The stacker mechanism may additionally comprise bottom shaper means 92 and 94 which help the stack to form evenly. The bottom shaper means 92 and 94 also hold the stack of papers off the conveyor belts 70 and 70a which are again continuously moving, so that there is no friction therebetween. When it is desired that the stack, having been completed, should be conveyed away from the stacking - nrea 66, the stacker gate 68, is pivoted about a pivot point 96 under the influence of an air cylinder 98 operated by the microprocessor as discussed in further detail below~ and releases the stack of papers. The bottom shaper means 92 and 94 being mounted commonly with the stacker gate 68 on a frame 69 allows the stack of papers to drop onto the continuously moving conveyor belts 70 and 70a and be conveyed away from the stacking g_ 3L~536~

area 66 for purposes of binding for ready transport. When the last paper of the stack has passed over the interrupter bars 50, they move upwards with respect to the papers catching the first paper of the next stack 82 and preventing the stream of papers P from going into the stacking area 66 while the stack of papers is being moved away therefrom. An air cylinder 99 may also be controlled by the microprocessor to push the stack out of the stacking area, and may simply operate by pushing the rods supporting the jogger plate 74.
Reference will now be made to Figures 5 and 6 for details of the stacker and jogger mechanisms. It will be noted from Figure 5 that the stack gate comprises a plurality of vertically extending rods 68 which, as shown in Figures 2 and 4, are mounted on a common frame assembly 69 pivoted about a pivot 96 under the influence of the air cylinder 98. Also mounted on frame 69 are bottom shaper means 92 and 94. It will be under-stood that the bottom shaper means 92 and 94 and the vertically extending rods 68 are adapted to slide between slots 100 formed in a base plate on which the jogger mechanisms and other parts of the assembly are mounted.
Between these~slots are mounted a plurality, in the preferred embodiment

3, of belts 70 and 70a. These serve to convey the papers away from the stacking area when the stack gate drops and the bottom shaper means 92 and 94 drop away from the underside of the stack of papers, thus permitting the stack o papers to fall on the belts 70. As shown, the central belt 70 may extend further back than those on the side 70a so as to avoid interference with the joggers. Back jogger means indicated generally at 110 are provided to shape the rear of the stack of papers. These comprise plates 112 driven back and forth, as indicated by arrows, by cams 114 driven by a shaft 25 which is, as shown in Figure 1, driven by a chain 8 ultimately powered by the motor 10. The plates 112 are driven ~153~

back and forth on spring loaded rods by means of cam followers 115 so that cam followers on the opposite side of the cams 1]4 are not requ;red. In this way, pusher cylinder 99 ~Figure 4) is enabled to push the jogger beyond the travel otherwise provided by the cams 114. The side joggers indicated generally at 124 operate in a similar fashion. These are driven by drive shafts 24 driven by gear box 22 (Figure 1) and comprise eccentric cams 116 operating on rollers 118 to which are mounted the side plates 120 which move back and forth, as indicated by the arrows, in order to ensure that the sides of the stack are formed neatly and regularly. It will be In ~mderstood by those skilled in the art that the entire side jogger assemblies 124 can be moved inwards and outwardly in order to compensate for overall variations in the width of the newspapers being stacked. As is the case with the belts, the joggers run continually, thus limiting mechanical stress and simplifying the machine.
Figure 6, a cross-section taken along the lines 6-6 of Figure 5, shows that the drive shaft 25 used to power the rear joggers is geared to a shaft 130 on which are mounted the eccentric cams 114 which in turn operate to drive the rollers 115 which are mounted on the carriage of the pusher plates 112, in this way providing a reciprocating motion to these plates so as to provide a back jogging motion to the stack being formed. The use of the gears permits variation in the jogging frequency if required. As discussed above, the pusher plates 112 can also be actuated by an air cylinder 99 (Figure 4) operated by the microprocessor so that when the stacker bars 68 drop, thus permitting the bottom shaper to allow the stack of papers to drop on the conveyor belt 70, these plates can be actuated saparately so as to push the stack of papers onto the conveyor belt to make sure that the stack is properly ejected from the machine. Since no cam followers are provided on the rearward side of the cams 114, the same 3~27 jogger plates 112 can be used for both functions, thus being controlled separately by air cylinder 99 and by the cams ll~.
Referring now to Figure 7, which is a block outline diagram of the microprocessor and associated control elements of the machine according to the invention, the control scheme of the machine will be described.
As discussed above, it is important that the mechanical operation of the various parts of the machine according to the invention be controlled accurately with respect to the passage of papers therethrough and that this be essentially independent of the relative speed of the incoming paper l~ str~am with respect to the speed of the belts conveying the papers within the stacking machine. Accordingly, the microprocessor indicated generally at 200 is provided with ;nput pulses, one per paper, from a paper counter 42, which as discussed above may comprise an off-the-shelf item. Micro-processor 200 is also provided with an input from a tachometer 204 which provides a machine-time measurement of the rotational speed of any one of the shafts. In a preferred embodiment a Veeder Root tachometer is used.
Since the shafts are all connected by non-slipping chains or essentially non-slipping belts, it is possible to take the speed measurement at any point. The fact that the belts are essentially non-slipping means that the tachometer count which might, for example, provide 10 pulses per inch travel of each belt, can be used to track the passage of a given paper through the system. Thus, for example, if it has been decided that a given stack of papers should contain 25 papers, when the 25th paper passes through the paper counter 42, the microprocessor then begins to count a number of counts corresponding to the distance between the paper counter and the end of the interrupter. ~Yhen enough counts have been counted to indicate that the end of this paper has just passed the interrupter, the solenoid valve controlling the air cylinder which operates the interrupter is energized; the interrupter ~ ~ ~ 3 ~ ~t~

then catches the tail of the next paper. In this way the stack is limited to the number desired.
The number of papers in a given stack is set by means of a key pad input 206 which is again a standard item and which may additionally be used to make adjustments in the operation of the machine. ~or example, in a case when the papers to be stacked are comparatively long it may be necessary to shorten the number of counts required between various steps in the process. Individual adjustment of the timing of the various processes described above also s~mpliiesinitial set-up of the machine. The micro-la processor may desirably also be arranged to operate a numeric display, indicated at 20S, to display to the operator the number of papers set to be stacked in a given stack and on which the number of counts ~i.e. a representation of time delay) between the various steps in the machine's operations can be displayed for adjustment as required. The microprocessor in turn operates the various air cylinders which control the moving parts of the machine. As discussed above, in the presently preferred embodiment, all the belts which move papers through the machine operate continually when it is turned on. The paper stream is moved in or out of engagement with these belts as required. Thus, for example, when the paper sensor 44 has its output interrupted indicating that a paper is present, the microprocessor co~mts a given number of counts enough to let the first paper be inserted between the pinch rollers 32 and 36, then energizes the air bags 34, thus pinching the pinch rollers closed. As discussed above, if the pinch rollers are kept closed at all times, the first paper tends to become jammed therebetween and cause a pile up. The delay built into the microprocessor's actuation of the air bags, which may be implemented through a solenoid controlling the supply of air pressure to the air bags 34, eliminates this difficulty. Similarly the microprocessor controls ~ ~ 5 3 ~ ~t~

solenoids which in turn allow the supply of air to the interrupter aircylinder~s) 54, the stack gate air cylinder(s) 98, and tha pusher air cylinder~s) 99. However, the disclosure of solenoids controlling air cylinders should not be construed to limit the scope of the invention to these presently preferred embodiments of means to power the machine's various operating parts. The microprocessor 200 may also be adapted to control the length of travel of the various air cylinders, and hence of the devices controlled thereby, by controlling the amount of time during which solenoids permit the application of air pressure to these cylinders. This is of use, for example, in connection with the pusher cylinder 99 which pushes the stack of papers onto the conveyor belts 70 and 70a. Stated differently, a tachometer driven by one of the shafts is used to sequence the various timed steps of the operation of the machine with respect to one another. For example, the tachometer working in combination with the microprocessor permits the tracking of the last paper of a given stack from the intercept, releases the catcher when the complete stack is formed and actuates the pusher simultaneously with releasing the intercept and allowing the paper stream once again to begin flowing touards the stacking area.
The use of a tachometer and a paper counter allow the machine to ~0 run in machine time and the use of chains keeps the machine overall in phase with itself. A speed controller 207 which may be a Burton Company unit comprising a 10:1 vernier potentiometer for accurate speed adjustment may be connected to allow the speed of the machine to be matched to that of the printing press to which it is connected without requiring individual adjustment of the timing of its internal operations.
It uill thus be appreciated that there has been described a machine for the stacking of newspapers which operates in machine time so as to eliminate difficulties of operation caused by lack of synchronization ~1~34~

between this machine and those to which it is connected in the stream of imbricated newspaper.
Another operating mode readily controllable by the microprocessor may be energized in jam-up situations to allow direct feed-through of papers.
In this case, the interrupter bars 50 are dropped out of the paper path, while the stack gate 68 is also dropped, so that the papers are permitted to flow through the machine without hindrance, thus clearing jam-ups.
~ oreover, it will be understood that the use of air bags and of a movable pinch roller r;sing up from beneath the stream o~ imbricated 1~) articles is of significance in that descending pinch rollers moved by air cylinders have been a source of severe vibration problems in the past. The use of air bags, being more resilient than air cylinders, enables the bags themselves to absorb some of the shock of the papers entering between the pinch rollers. ~loreover a higher squeeze pressure is thus permitted without excess vibration so that the papers can be more tightly creased and better stacked. It will also be appreciated that the fact that the various air cylinders of the system are each individually controlled allows their pressures to be tailored to their use, again so as to eliminate unnecessary rouglmess or stress in the operation of the machine and adding to its ~n service life.
Finally, it will be appreciated that the use of a pinch roller mounted on a pivoting arm supported by air bags and coming up from beneath thejmbricated stream rather than descending from above as was done in the prior art, permits the air bags, rather than the papers, to support the weight of the roller, which may be as much as 50 pounds in a preferred embodiment where significant inertia is desired. Additional air pressure is then added to regulate the amount of pinch pressure exerted. It will be appreciated that if the roller were pivoted so as to descend on the ~S3~Z7 stream of imbricated papers from above, the entire weight of the roller would bear down on and be moved by the stream of papers, and would be a source of the severe vibration which has been a difficulty in prior art stacking machinery.
Further, it will be understood that various improvements and refinements can be made to the mach;ne as disclosed without departing from its scope. For example, it will be understood by those skilled in the art that the shape of the bottom shapers for the stack can be of importance.
So too can be the shape of the paper when ejected from the belts 62 and 64. In some embodiments and with some sorts of papers it is desirable that each paper be given a V-fold ~looking in the direction of travel of the papers) when being ejected into the stacking area so as to prevent it from buckling in the transverse direction. Means to accomplish these ends will readily occur to those skilled in the art.
Therefore, the above description of the preferred embodiment of the invention should not be taken as a limitation of its scope which is as defined by the following claims.

Claims (10)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. Apparatus for creasing and stacking a stream of imbricated articles, said stream being essentially horizontal and said imbricated articles having a major fold substantially perpendicular to the direction of said stream, said apparatus comprising:
means for establishing said substantially horizontal flow path through said machine;
means for interrupting progress of said stream upon completion of a stack;
means for catching ones of said imbricated articles in said stream to form said stack;
means for ensuring that said articles are stacked regularly;
means for counting said articles in each stack being formed; and means for creasing said articles, said means for creas-ing said articles comprising:
a pair of rollers through which said stream is constrained to pass, said rollers having horizontal axes generally perpendicular to the direction of said stream, the one of said rollers above said stream being fixed with respect to said stream and the one of said rollers beneath said stream being mounted resiliently; and means for biasing said lower roller into engagement with said imbricated articles in said stream so as to crease said major fold as said articles pass between said opposed rollers.

2. The apparatus of claim 1 further comprising micro-processor and monitor means to control the operation of said interrupter means so as to define the number of imbricated articles in any one stack.

3. The apparatus of claim 1 wherein said lower roller is mounted on pivotable arm means and is biased into engagement with said stream by inflatable air bag means.

4. In apparatus for the creasing and stacking of a generally horizontal stream of imbricated articles having a major fold aligned generally perpendicularly to the direction of travel of said stream comprising means for counting said articles for stacking said articles, for interrupting the stream of said articles to permit the conveying of a stack away from said machine when said stack is completed, and for creasing said articles, the improvement which comprises:
said creasing being performed by a pair of opposed rollers disposed on either side of the stream of articles, the axes of said rollers being generally horizontal and perpendicular to the direction of travel of said stream, the upper one of said rollers being rigidly mounted and the lower of said rollers being resiliently mounted whereby the lower of said rollers is biased into engagement with said stream to cause said major fold to be effectively creased.

5. The apparatus of claim 4 wherein said resilient mounting comprises inflatable air bag means.

6. The apparatus of claim 4 further comprising micro-processor and monitor means for controlling operation of said apparatus.

7. The method for stacking and creasing a stream of imbricated articles, said stream being generally horizontal and comprising articles having a major fold disposed generally transversely to the direction of travel of said stream comprising the steps of:
creasing said articles by causing said stream to flow between opposed rollers having generally horizontal axes, the upper one of said rollers being rigidly mounted and the lower of said rollers being resiliently mounted; and stacking said articles and interrupting said stream when a stack of said articles is completed to permit the conveying of said stack away from the stacking area.

8. The method of claim 7 wherein said lower roller is biased into engagement with said stream of imbricated articles by supplying air pressure to resilient air bag means arranged to press said roller into engagement with said stream of imbricated articles.

9. In a method for stacking and compressing a stream of imbricated articles comprising the steps of:
catching ones of said articles in stacking means, interrupting said stream when said stack. is completed and compress-ing said articles prior to stacking said articles, the improvement which comprises:

compressing said articles by passing said stream of articles between opposed rollers having generally horizontal axes, the upper one of said rollers being rigidly mounted and the lower of said rollers being resiliently mounted, the lower of said rollers being pivotably mounted for engagement with said stream of articles upon energization thereof.

10. The method of claim 9 wherein said lower roller is biased into engagement with said stream by supply of pressurized air to resilient air bag means.