Apparatus For Stacking Flexible Sheets

Abstract

Apparatus and methods for stacking flexible sheets, including signatures of magazines, books, newspapers and the like: A stream of overlapped signatures, continuously transported toward the left along a horizontal path from an initial location to a second location, is then intermittently fed about an inclined path from the second location at an inclined angle upward toward the left and about an arcuate path and downward to the left at an angle of 45.degree. with the horizontal to feed the overlapped signatures, serially, to a V shaped input bin. The input bin has a first movable wall and a second wall, whereby the leading edge of each of the signatures abut against the second wall and wherein each of the signatures fed into the input bin operate to form a stack therewithin with the bottom surface of the bottommost signature resting on first wall, and the other signatures aligned in a stack thereabove with the leading edges of each of the stacked signatures resting against the second wall. The overlapped signatures are fed, at an average surface speed, until the input bin is full. The feeding is then halted to enable the input bin to be unloaded. The transporting and feeding operation are so performed with the input bin that an imaginary point on one of the signatures travels in a first locus lying in a single plane. Similarly, an output bin, including a V shaped trough having a first wall and a second wall, and a third bin, intermediate the two bins, including a V shaped trough having a movable first wall and a second wall, are provided. The third bin further includes a fixed ceiling opposed to its first wall. A conveying means is coupled to each of the second walls of the three bins, which second walls are likewise movable. The second bin, the intermediate third bin, the output bin, and a conveying means are so oriented that the aforesaid imaginary point on one of the signatures travels in a second locus lying wholly in a plane perpendicular to the single plane. A stack of signatures, formed in the input bin, is indexed to the third bin, wherein they are compressed by the action of the first wall moving up against the compression ceiling, and, later, a compressed stack of signatures in the third bin is transported to the output bin, whereupon such compressed stack of signatures can be unloaded manually or by other suitable means.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to signature stacking apparatus and methods. Accordingly, the general objects of this invention are to provide new and improved devices and methods of such character.

2. Description of the Prior Art

The following U.S. Patents, knwon to the applicant, may be of interest for their delineation of the prior art:

694,634 Griswold 1,001,507 Cox 1,063,338 Duncan 2,053,315 Barnecott 2,261,972 Matthews 2,381,430 Belluche 2,527,911 Buccicone 2,758,838 Ward et al. 2,772,880 Garrett 2,815,210 Weber et al. 2,841,394 A. R. Stobb 2,853,298 Faeber 2,884,243 A. R. Stobb 2,933,313 A. R. Stobb 2,933,314 A. R. Stobb 3,188,082 A. R. Stobb 3,483,817 A. R. Stobb 3,501,139 A. R. Stobb

U.S. Pat. No. 694,634 to Griswold at FIG. 3 thereof shows a feed means between belts to stripper. Cams 23 (a) support a box in travelling relationship as can be seen from FIG. 8 thereof and vertical stripper 24 (a).

U.S. Pat. No. 1,001,507 to Cox shows a feed between belts 16 and 23 wherein the objects are stripped by an inclined plate 37, Packer fingers 41 rock back and forth.

U.S. Pat. No. 1,063,338 to Duncan discloses an envelope feeding mechanism wherein the envelope is fed downwardly and forwardly and then upwardly to a discharged position above the initial feeding position by means of various feed rolls and tapes.

U.S. Pat. No. 2,053,315 to Barnecott discloses a delivery apparatus, wherein overlapped tabloid papers are guided upward between opposed conveyor belts, curving around toward the right and deposited upon a conveyor in a stacking type formation.

U.S. Pat. No. 2,261,972 discloses a plurality of overlapped sheets being fed by conveyor belts to a stop 42 at the side of the lay-boy 40.

U.S. Pat. No. 2,381,430 to Belluche, which discloses a sheet delivery mechanism, includes a platform or other support upon which the delivered sheets are stacked or piled. A suitably mounted guide provides a stop against which the sheets are drawn by a driven friction roll which may be raised and lowered in timed relation with the advance of the sheets to the pile. The sheets can be fed in overlapped relation so that the sheets on a tape conveyor are stream fed.

U.S. Pat. No. 2,758,838 to Ward et al. discloses, at FIG. 15 thereof, a combination underfeed and lap stacker, wherein sheets are fed between belts and onto means 8 under a stack. Means 60 serve to strip the sheets from means 8.

U.S. Pat. No. 2,772,880 to Garrett discloses a sheet stacker including a belt feed in overlapping relationship wherein the material is stripped from the conveyor.

U.S. Pat. No. 2,815,210 to Weber et al. discloses appratus for stacking bags and the like wherein overlapped bags are conveyed along a belt 16 against an inclined back stop 21a. It is noted that the inclined backstop 21a of Weber et al. is inclined at a slight angle from the vertical to enhance substantially vertical stacking of the bags, as set forth at column 4 thereof.

U.S. Pat. No. 2,841,394 to A. R. Stobb, discloses a collector for flexible sheets. In one embodiment, a plurality of signatures are transported in overlapped formation, wherein the sheets are transported along a horizontal path with each signature maintained horizontal. By means of conveyor belts, the signatures are twisted along a path approximating that of the vertical. The signatures are then fed into a packer box or receiver so that the signatures are stacked therewithin, wherein each signature is stacked on an edge thereof. Periodically, an attendent can remove a group of the signatures adjacent a weight, and thereafter reposition the weight against the stack remaining in the box. In a modification of A. R. Stobb, as depicted in FIGS. 4 and 5 thereof, signatures are advanced to a horizontally disposed and rotatable turning drum, wherein the signatures pass thereover and are engaged by a pair of drive belts, with the belts suitably mounted within pulleys to align the belts with other belts, whereby the sides of the signatures are firmly supported. The signatures are eventually tucked into a receiver or box in a vertical position. The box can contain only one side, since the box is tilted towards that side and the sections are caused to move to the side. As stated therein, the tilt and the box side are not necessary to produce properly aligned and stacked sections.

U.S. Pat. No. 2,853,298 to Faeber relates to a delivery mechanism for signatures, wherein the signatures are carried in overlapping fashion by a moving conveyor which approaches the moving platform upon which the signatures are to be stacked at a somewhat higher level than the platform. The conveyor travels around a curved guide which deflects the signatures carried by the conveyor toward the receiving end of the moving platform. The signatures are engaged by an upper moving belt, as they are deflected around a curved guide, to reduce slippage due to gravity. The signatures are then directed in a substantially vertical plane with the leading edges thereof coming into contact with the moving platform. Because of the overlapping relation of the signatures, they drop down onto the moving platform, one behind another in succession. In order that the various signatures have their bottom edges thereof in registered contact with the platform, a jogging device, together with a vibrating device, is utilized to vibrate the moving platform, so that the lower edges of the signatures fall into registration with the platform.

As stated by Faeber, the signatures are assembled and advanced by the moving platform and stacked array. As the signatures are transported to the discharge end of the platform, the sides of the signatures are engaged by moving belts which have a jogging action on the signatures. As the leading signatures approach the discharge end of the moving platform, groups of the signatures may be removed by hand or other suitable means. In one embodiment, the conveyor which carries the signatures in overlapping fashion toward the receiving end of the moving platform, and the moving platform, move in opposite directions one above the other to save floor space. In another embodiment, the operative lengths of the feed conveyor and the moving platform travel in the same direction.

U.S. Pat. No. 2,884,243 to A. R. Stobb discloses a process and apparatus for collecting and stacking of flexible sheets, such as signatures, which are disposed in an overlapped relation on a conveyor. The signatures are guided to a receiver where a stop automatically strips them off and the signatures are stacked in aligned relation in the receiver. A plurality of conveyor belts, disposed adjacent and parallel to the conveyor and movable therewith, confine the signatures to guide them in an edgewise direction. The belts extend across the receiver for pulling the signatures completely to their aligned relation. A fixed stop, disposed transversely across the edgewise path of travel, interrupts the edgewise movement of the signatures. The belts are disposed with the side and the center ones of the belts in their extents adjacent the stop being offset with respect to each other along the length of the receiver, all for arcuately disposing the signatures along their leading edges when the latter abut the stop. The reference further discusses a conveyor which has endless belts movable across the entire entrance to a receiver in an upward direction, with the receiver being disposed toward the side of the belts such that the leading edges and a part of one of the sheets are in contact with the belts and that the receiver is disposed toward the opposite side of the sheets. The belts are extended beyond one end of the stack to pull the leading edges completely to their aligned relation in the stack. The extension of the belts are oriented with the end of the stack so that the stream of the sheets is pressed by the extension of the belts against the entire end of the stack and the receiver. A stop is projected into the path of the sheets for stripping the latter off the conveyor and forming them into the stack in the receiver.

U.S. Pat. No. 2,933,313 to A. R. Stobb discloses a method and means for collecting flexible sheets. A plurality of overlapped signatures are fed along a horizontal path and are guided by conveying belts along a vertical path rising upward against a stop. The signatures are then conveyed in their vertical orientation along a horizontal path in the same direction as the initial horizontal path. The bottom edge of each signature is guided out of the way of oncoming signatures by means of a knurled roller 60 to provide a means for frictionally and positively engaging the trailing edges of the signatures and advancing them along the horizontal path.

U.S. Pat. No. 2,933,314 to A. R. Stobb discloses a method and means for collecting and stacking flexible sheets. The signatures are fed between a pair of pulleys 22 and 29, between conveyor belts 11 and 12, and up along a path indicated by arrows, and over a pulley 24 in an inclined angle upwards between a pair of pulleys 18 and 26, and are carried past the pulley 26 by an upper conveyor belt 38 and, on the lower side, along a lowermost signature on a paper stack. The pulley 26 rotates in a clockwise direction to cause the lower end of the signatures to be brushed or moved away from the pulleys 18 at the entrance of the stream to the receiver. A conveyor lowers the stack at the speed in which the stack is growing and increasing. The stack is lowered along an inclined plane by the conveyor. After a period of time, a separation plate is inserted into the stack to separate the stack at a particular point. The separation plate supports the incoming sheets which are lowered above it so that a full stack can be lowered to a lowermost position, as shown in FIG. 3 thereof. The lowered stack can be compressed by a compressor unit to permit a rope to be tied around the stack to bind the same, as described at column 4, lines 55 through 68 thereof. When the stack is bundled, it can be removed from the receiver, and the new stack can be formed by the incoming sheets.

U.S. Pat. No. 3,188,082 to A. R. Stobb describes an apparatus and method for collecting flexible sheets. Signatures are carried from a printing press (not shown) onto a conveyor between various conveying belts, and about drums or rollers, up and around in a counterclockwise direction forming a path somewhat transverse to the original path, wherein it is stripped from the conveyor, and placed in a stacked relation on a platform directed away from the device or drums. Thus, the conveyor is operated at such a level, that the sheets are turned somewhat upside down as they come in the stream, and are placed into the box or onto the conveyor under the platform. The platform is readily accessible to an attendant who takes the stack of sheets from the platform and ties them if he so desires. The platform is disposed at an inclined angle with respect to the horizontal, and the conveyor is also so disposed such that the incoming stream is generally transverse to the plane of the platform.

U.S. Pat. No. 3,483,817 to A. R. Stobb discloses a method of stacking and bundling sheets by moving them in an echeloned stream, stripping the sheets from the stream, and forming them in a stack along one line, separating part of the stack to one side of the line and against the stop and compressing and typing the stacked part while it is against the stop.

U.S. Pat. No. 3,501,130 to A. R. Stobb discloses a method and means for stacking signatures through the use of means and a method for conveying signatures in a stream and then having the signatures reverse in the stream, and then having the signatures reverse in their end to end relation so that the original trailing edge becomes the leading edge. The reversed stream of signatures is conveyed to a receiver where the signatures are stacked in alignment and the receiver is jogged for final alignment of the signatures in the stack.

In high speed web printing presses, it was customary to deliver the printed and folded sheets onto a conveyor belt, operating at a speed synchronized with the press speed. These signatures were generally positioned in an overlapping and stepped or echeloned relation in the order that they came off the press. Usually, an attendant then scooped the signatures off the belt, an armful at a time, lined them up, pressed them flat, and finally placed them onto a truck. Only a limited number of signatures could be handled that way, at one time, and additional attendants were thus required to keep up with the speed of delivery.

Delivery machines have been made, wherein the signatures are collected in a pile directly coming out of the maachine. Such method required reciprocating pushers which had to be out of the way each time a signature is delivered. The speed of that type of machine was thus limited.

Thus, there was a demand for automatic signature stacking mechanisms and various of the patents described hereinabove were designed to solve such problem. Various processes and apparatus for collecting and stacking flexible sheets, such as signatures, which were fed from a printing press are known. Many, however, require either elaborate and therefore different non-analagous apparatus or are not designed to collect flexible sheets. In the past, the work of two or three laborers was required to scoop the sheets off a conveyor belt and stack and pack them and then tie them. In some prior art devices, comparatively complicated mechanisms are required for transporting the sheets from a horizontal path and into a bin, and then subsequently compressing a stack of signatures for subsequent handling and being carried away by a workman. Various prior art devices and methods were awkward and undesirable from one or more points of view.

SUMMARY OF THE INVENTION

It is an object of this invention to provide a new and improved method and apparatus for stacking signatures.

Still another object of this invention is to provide a new and improved method and apparatus for transporting a continuous stream of signatures from a printing press, at printing press speeds, forming them into stacks of signatures, and unloading the stacks of signatures for subsequent handling.

Yet another object of this invention is to provide new and improved methods and apparatus for continuously transporting signatures, provided at printing press speeds, from an initial location in proximity with the printing press to a subsequent location, and for intermittently feeding signatures at the subsequuent location about a path to fill an input bin with the signatures, whereby upon filling the input bin, the feeding of the signatures is halted. Upon unloading the input bin of the signatures, the stream of signatures can be again fed from the subsequent location to the input bin.

Still another object of this invention is to provide new and improved methods and apparatus for continuously transporting signatures provided at printing press speeds from a location in proximity with the printing press to a subsequent location with which compressed stacks of signatures are formed.

In accordance with one embodiment of this invention, signatures can be stacked by utilizing an input bin and an output bin, each adapted to receive a stack of signatures. A third bin, oriented intermediate the input bin and the output bin, is also provided. A stream of overlapped signatures is transported from an initial location toward the input bin. In cooperation with the transporting step and the input bin, the overlapped signatures can be fed serially so as to fill the input bin with a stack of signatures. The transporting and the feeding are performed in relation to the input bin so that an imaginary point on one of the signatures travels in a first locus lying in a single plane. Means in association with the third bin compress a stack of signatures therewithin. Stacks of signatures are conveyed in a line from the input bin to the third bin and to the output bin so that the imaginary point on one of the signatures travels in a second locus lying wholly in a plane perpendicular to the single plane. In accordance with specific features of the invention, thhe input bin and the third bin each includes a V shaped trough having a movable first wall and a second wall. The output bin includes a V shaped trough having a first wall and a second wall. All the first walls are oriented in either co-planar or parallel planar relation to each other. All the second walls are coaligned with relation to each other and, when viewed along the line from one bin to another bin, the first walls are each oriented substantially upward toward the right at a 45.degree. angle with the horizontal plane, and the second walls are each oriented substantially upward toward the left at a 45.degree. angle with the horizontal plane. In a specific feature, the second walls can be conveyed. Further, in accordance with a specific feature of the invention, the signature stacking apparatus further includes a fixed upper compression ceiling oriented above the third bin movable first wall and parallel thereto. Individual driving means are provided for transporting means, feeding means, the input bin first wall, conveying means, and to compressing means in conjunction with the third bin first wall. Detecting means are provided individually for sensing that the input bin first wall is at its uppermost position, for sensing that the input bin first wall is at its lowermost position, and for sensing that the third bin first wall is at its lowermost position. In association with each of the driving means and the detecting means, timing means are provided for causing the following sequence to take place: that the first driving means continuously activates the transporting means; with the fourth driving means halted, the first detecting means senses that the input bin first wall is at its uppermost position, the second driving means activates the feeding means to feed signatures serially to the input bin to form a stack so that the bottom surface of the initially fed signature rests on the input bin first wall and an edge of each of the signatures of the formed stack rests against the input bin second wall, the third driving means gradually lowers the input bin first wall until the input bin is full, and the fifth driving means causes the compressing means to raise the third bin first wall upward to the left towards the fixed compression ceiling so as to compress a stack of signatures residing in the third bin. When the second detecting means senses that the input bin first wall is at its lowermost position, the second driving means is halted and the third driving means is disengaged from the input bin first wall, and the fifth driving means causes the third bin first wall to lower to its lowermost position. Upon the third detecting means sensing that the third bin first wall is at its lowermost position, the fourth driving means is indexed to transport a full stack of signatures from the input bin to the third bin, and to transport a stack of compressed signatures from the third bin to the output bin. Upon clearance of a full stack of signatures from the input bin, the input bin first wall is driven by the third driving means rapidly upward to its uppermost position, and, upon completion of the indexing of the stacks of signatures by the fourth driving means, the fourth driving means halts and the foregoing sequence is repeated.

In accordance with another embodiment of the invention, an input bin, including a V shaped trough having a movable first wall and a second wall, is adapted to receive a stack of signatures. An output bin, adapted to receive a stack of signatures, includes a V shaped trough having a first wall parallel to or coaligned with the input bin first wall, and a second wall coaligned with the input bin second wall. When viewed along a line from one bin to another bin, the first walls are each oriented substantially upward toward the right at a 45.degree. angle with the horizontal plane, and the second walls are each oriented substantially upward toward the left at a 45.degree. angle with the horizontal plane. Means are provided for transporting a stream of overlapped signatures from an initial location toward the input bin. Means in cooperating relationship with the transporting means and the input bin are provided for feeding the overlapped signatures, serially, to the input bin so as to fill the input bin with a stack of signatures. The transporting means, the feeding means, and the input bin are so oriented that an imaginary point on one of the signatures travels a first locus lying in a single plane. Further means convey a stack of signatures from the input bin to the output bin. The input bin, the conveying means, and the output bin are so oriented that the imaginary point on the said one of said signatures travels in a second locus lying wholly in a plane perpendicular to the single plane. In specific versions of the invention, the second walls can be conveyed. In another feature of the invention, the input bin first wall is movable along a path upward to the left along a line oriented at a 45.degree. angle with the horizontal plane and downward toward the right along the line, wherein the input bin first wall is at its uppermost position at an initial load condition and is at its lowermost position at a full load condition. In a specific feature of the invention, individual driving means can be provided for the transporting means, the feeding means, the input bin first wall, and the conveying means. Individual detecting means are provided for sensing that the input bin first wall is at its up permost position and at its lowermost position. Timing means, in association with the driving means and the detecting means cause a sequence of operations to take place so that the first driving means continuously activates the transporting means. With the fourth driving means halted and the first detecting means sensing that the input bin first wall is at its uppermost position, the seccond driving means activates the feeding means to feed signatures serially to the input bin to form a stack, so that the bottom surface of the initially fed signature rests on the input bin first wall and an edge of each of the signatures of the formed stack rests against the input bin second wall. The third driving means gradually lowers the input bin wall until the input bin is full. When the second detecting means senses that the input bin first wall is at its lowermost position, the second driving means is halted, the third driving means is disengaged from the input bin first wall and the fourth driving means is indexed to transport a full stack of signatures from the input bin toward the output bin. Upon clearance of a full stack of signatures from the input bin, the input bin first wall is driven by the third driving means rapidly upward to its uppermost position, and upon completion of the indexing of the full stack of signatures by the fourth driving means, the fourth driving means halts and the sequence is repeated.

In accordance with another embodiment of the invention, a bin receives a serial stream of overlapped signatures fed at the top thereof so as to form a stack of signatures within the bin. A first conveyor belt, having its upper working surface oriented along a horizontal path, transports a multiplicity of overlapped signatures from an initial location to a second location. Means continuously drive the first conveyor belt. The overlapped signatures are fed from the second location, upward along an inclined path and then, curving past the horizontal, are ejected to the bin. Means halt the feeding of the overlapped signatures when the bin is full, so that a stream of overlapped signatures continues to be fed by the conveyor belt, so that a plurality of overlapped signatures are formed in overlapping orientation at the inclined path at the second location. This permits a full stack of signatures to be unloaded from the bin. The foregoing means further drives the feeding of the overlapped signatures after the bin was unloaded so as to reload the bin with another stack of signatures. In accordance with specific features of the invention, the first conveyor belt is driven at a constant linear speed r.sub.1 and the feeding is alternately operated at an average linear speed r.sub.2 for an average load time period t.sub.1 and halted for an average unload time period t.sub.2. In a specific feature, the following relation r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1 is true.

In accordance with another embodiment of the invention, an input bin has a V shaped trough having a first wall oriented in an upper right direction, as viewed by an observer, forming a 45.degree. angle with the horizontal plane and has a second wall oriented in an upper left direction forming a 45.degree. angle with the horizontal plane. The first wall can be moved gruadually downward toward the right along a 45.degree. angle with the horizontal and rapidly upward toward the left along the 45.degree. angle to form a shallow bin for receiving a few signatures when the first wall is at its uppermost position and to form a full bin for receiving a full stack of signatures when the first wall is at its lowermost position. A stream of overlapped signatures is transported from a first location along a horizontal path forward the left to a second location. The transporting of the stream is continuously operated so that the overlapped signatures are traversed from the first location to the second location at a constant linear speed r.sub.1. The overlapped signatures are fed from the second location at an inclined angle upward toward the left and about an arcuate path and downward to the left at an angle of 45.degree. with the horizontal to feed the overlapped signatures serially to the input bin. The leading edge of each of the signatures abut against the second wall. The signatures fed into the input bin operate to form a stack therewithin with the bottom surface of the bottommost signature resting on the first wall and the other signatures aligned in a stack thereabove with the leading edges of each of the stack signatures resting against the second wall. The feeding is alternately performed at an average surface speed r.sub.2 for the overlapped signatures for an average duration t.sub.1 until the input bin is full and is halted for an average unload period t.sub.2 to enable said input bin to be unloaded. As before, specifically in a feature of the invention, the relationship r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1 is likewise true. In various modifications of the invention, the feeding, the transporting, and the input bin are so oriented that an imaginary point on one of the signatures travels in a first locus lying in a single plane. Further, a V shaped output bin is provided having a first wall oriented at a 45.degree. angle in an upward right direction with the horizontal plane and a second wall oriented in a 45.degree. angle in an upper left direction with the horizontal plane. The first walls are oriented in either coplanar or parallel planar relation and the second walls are oriented in a coplanar relation. A stack of signatures is conveyed from the input bin to the output bin in such a manner that the imaginary point on one of the signatures travels in a second locus lying wholly in a plane perpendicular to the single plane. The second walls are movable within a plane parallel to the second locus plane so that the second walls are coupled to and moved by the conveying means.

In a specific and detailed embodiment of the invention, an input bin having a V shaped trough has a first wall oriented in an upper right direction, as viewed by an observer, forming a 45.degree. angle with the horizontal plane and a second wall oriented in an upper left direction forming a 45.degree. angle with the horizontal plane. Similarly, an output bin having a V shaped trough has a first wall oriented at a 45.degree. angle in an upper right direction with the horizontal plane, and a second wall oriented at a 45.degree. angle in an upper left direction with the horizontal plane. A third bin is oriented intermediate the input bin and the output bin, the third bin having a V shaped trough with an inclined ceiling thus forming a three-sided bin. The third bin includes a first wall oriented at a 45.degree. angle in an upper right direction with the horizontal plane, whereby all of the first walls lie within planes parallel or coplplanar with each other. A second wall is oriented at a 45.degree. angle in an upper left direction with the horizontal plane, whereby all of the second walls lie in a common plane, and a fixed upper compression ceiling is oriented above the third bin first wall and parallel thereto. The first wall of the input bin can be moved gradually downward to the right along a 45.degree. angle with the horizontal and rapidly upward to the left along the 45.degree. angle to form a shallow bin for receiving a few signatures when the input bin first wall is at its uppermost possition and to form a full bin for receiving a full stack of signatures when it is at its lowermost position. A stream of overlapped signatures is transported from the first location along the horizontal path toward the second location. First means are provided for continuously transporting the stream of signatures so that the overlapped signatures are traversed from the first location to a second location at a constant linear speed r.sub.1. The overlapped signatures are fed from the second location at an inclined angle upward to the left and about an arcuate path and downward to the left at an aangle 45.degree. with the horizontal to feed the overlapped signatures serially to the input bin. The leading edge of each of the signatures abut against the second wall thereof. Each of the signatures fed into the input bin operate to form a stack therewithin with the bottom surface of the bottommost signature resting on the first wall and the other signatures aligned in a stack thereabove with the leading edges of each of the stacked signatures resting against the second wall thereof. Second means drive alternately the feeding at an average surface speed r.sub.2 for the overlapped signatures for an average duration t.sub.1 until the input bin is full, and halt the feeding for an average unloading period t.sub.2 to enable the input bin to be unloaded. The feeding, the transporting, and the input bin are so performed or oriented that an imaginary point on one of the signatures travels in a first locus lying in a single plane. A stack of signatures is conveyed from the input bin to the third bin and to the output bin so that the imaginary point on one of said signatures travels in a second locus lying wholly in a plane perpendicular to the foregoing single plane. Additional means are provided for driving the moving means and the conveying means, and for driving the third bin first wall upward toward the fixed upper compression ceiling for compressing a stack of signatures therebetween and for returning the third bin first wall to a lowermost position in order to receive an uncompressed stack of signatures in the third bin trough. Separate detecting means sense that the input bin first wall is at its uppermost position and at its lowermost position, and sense that the third bin first wall is at its lowermost position. In association with all of the foregoing driving means and detecting means, timing means cause the following sequence to take place: that the first driving means continuously activates the transporting means and, with the fourth driving means halted and the first detecting means sensing that the input bin first wall is at its uppermost position, the second drive means activates the feeding means to feed signatures serially to the input bin to form a stack, so that the bottom surface of the initially fed signature rests on the input bin first wall, and an edge of each of the signatures of the formed stack rests against the input bin second wall. The third driving means gradually lowers the input bin first wall until the input bin is full. The fifth driving means causes the third bin first wall to rise upward to the left toward the fixed upper compression ceiling so as to compress a stack of signatures residing in the third bin. When the second detecting means senses that the input bin first wall is at its lowermost position, the second driving means halts and the third driving means is disengaged from the input bin first wall. The fourth driving means causes the third bin first wall to lower to its lowermost position. Upon the third detecting mean sensing that the third bin first wall is at its lowermost position, the fourth driving means is indexed to transport a full stack of signatures from the input bin to the third bin, and to transport a stack of compressed signatures from the third bin to the output bin. Upon clearance of a full stack of signatures from the input bin, the input bin first wall is driven by a third driving means rapidly upward to its uppermost position, and upon completion of the indexing of the stacks of signatures by a fourth driving means, the fourth driving means halts and the sequence including the foregoing steps are repeated. As before, in accordance with the specific feature of the invention, the following relation r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1 is likewise true.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, advantages and aspects of the invention will become apparent by reference to the following detailed specification and drawings of a specific embodiment thereof, wherein:

FIG. 1 is an elevational view of one embodiment of the invention, showing a housing covering protions thereof;

FIG. 2 is an oblique plan view of the embodiment shown in FIG. 1 taken along the line 2--2 thereof;

FIG. 3 is a view similar to FIG. 1, with portions of the housing removed;

FIG. 4 is a view taken along the line 4--4 of FIG. 3;

FIG. 5 is an electrical schematic of one embodiment of this invention;

FIG. 6 is a partial detailed view of a portion of FIG. 3, illustrating a cam and switching arrangement;

FIG. 7 is a detailed view showing a portion of a rack and switch depicted in FIG. 3; and

FIG. 8 is a view, similar to FIG. 7, depicting the rack in engagement with another switch.

Referring to the drawings, specifically FIGS. 1 and 3 thereof, there is shown an apparatus 10 for stacking signatures, such as sheets used for books, newspapers, and the like. Signatures 12--12 are transported from an initial location, such as a printing press (not shown) and carried continuously towards the left toward a subsequent location 14.

The signatures 12--12 are continuously transported by suitable means, such as a motor 16, which drives a driving pulley 18 via a suitable shaft 20. An endless conveying belt 22, forming a closed loop, is engaged by the driving pulley 18 at one end thereof, and is engaged by an idling pulley 24 at the opposite end thereof. The idling pulley 24 engages the conveyor belt 22 at a point proximate to the subsequent location 14. The idling pulley 24 is supported about a shaft 26 which is housed in a housing 28.

The signatures 12--12 are fed from the subsequent location 14 upward about an inclined angle, curving arcuately about the top thereof, and downward at an inclined angle, by a feeding means indicated generally at 30. The feeding means includes a pair of conveying belts 32, 34. Each belt 32 and 34 includes a plurality of endless straps disposed symmetrically about various rollers, including the idling pulley 24 for the belt 32.

The conveying belt 32 is disposed about the idling pulley 24 and a driving pulley 36. Both the conveying belts 32 and 34 obtain their drive by virtue of the driving pulley 36. The belt 34 is also engaged by an idling pulley 38. The belt 32, which is engaged at its opposite ends by the pulleys 24 and 36, is carried about a path determined by a guide plate 40 so that the belt traverses a curved or arcuate path. The undersides of the signatures 12--12 are carried along the top surfaces of the conveying belts 32, 34, as shown in FIG. 1.

A pair of pulleys 42, 44, which engage an endless belt 46, is permitted to idle above the stream of signatures 12--12, so that the signatures 12--12 are fed between the belts 46 and the belts 32, 34.

The pulley 42, which is relatively heavy and may weigh approximately 80 pounds, is supported about a shaft 48 which is coupled to an arm 50. The arm 50, in turn, is coupled about a shaft 52 which is connected the housing 28.

An idling pulley 54, which is disposed opposite to the idling pulley 38, engages the signatures 12--12 as they pass therethrough. The idling pulley 54 is coupled via its shaft 56 to a link 58, which link is coupled by a pivotal connection 60 to the arm 50.

A jogging mechanism 62, as depicted generally in FIG. 3, is provided to insure proper top to bottom jog on a stack, as is well known to those skilled in the art. The driving pulley 36 is coupled by a belt 64 to a D.C. motor 66. Thus, at this stage, signatures 12--12 are continuously transported along the belt 22 to the location 14, and are fed about the arcuate path by the belts 32, 34, and 46. The overlapped signatures 12--12 are ejected through the pulleys 54 and 38, one at a time, downward in a lower left direction, at a 45.degree. angle with the horizontal plane.

The signatures 12--12, which are ejected by the jogging mechanism 62 from the idling pulleys 54 and 38, are directed into an input bin 68. The input bin 68 is formed with a V shaped trough having walls at 45.degree. angles with the horizontal. One wall of the V shaped trough includes a lowering plate 70. The lowering plate 70 is coupled at its lower end to a rack 72. The rack 72 passes through the housing 28 and is engaged by a pinion gear 74, which, in turn, is driven by a motor 76. The motor 76 drives the pinion gear 74 through a clutch 78, as depicted at FIG. 4.

The clutch 78 is coupled to the motor 76 and to the pinion gear 74 so as to gradually lower the rack 72 and, hence, the lowering plate 70 in a downward direction along a line 45.degree. with the horizontal.

Referring specifically to FIG. 3, a weight 80, which is carried by a chain 82, is elevated as the lowering plate 70 is lowered. The chain 82 is wrapped about a sprocket 84.

After the lowering plate has been fully lowered, the clutch 78 can be disengaged from the motor 76, and the weight 80, being coupled about the sprocket 84, can drive the rack 72 rapidly upward so that the lowering plate 70 is raised to its uppermost position. The timing relationship with regard to the lowering and raising of the plate 70 is described in greater detail hereinafter.

The other wall of the input bin 68 is formed, in part, by an endless indexing conveyor belt 86.

The signatures 12--12, thus, are fed from a printing press, or the initial location, along a path into the input bin 68 and onto the lowering plate 70, so that an imaginary point on one of the signatures 12--12 traverses the locus lying in a single plane, whereby the imaginary point may traverse a path in the direction shown by the arrow labelled A in FIG. 2.

Referring more specifically to FIG. 2, an output bin 88 is provided including a V shaped trough. The V shaped trough is arranged parallel to the V shaped trough of the input bin 68. The output bin 88 includes a first wall 90 which is parallel to or coplanar with the lowering plate 70 of the input bin 68. The other wall of the output bin 88 is formed with a plurality of rollers 92--92. The wall, formed by the rollers 92--92, is arranged coplanar with the wall of the input bin 68 formed by the conveying belt 86.

Intermediate the input bin 68 and the output bin 88 is a compression station 94. The compression station 94, as best shown at FIG. 4, includes a V shaped trough, again arranged in parallel relation to the V shaped troughs of the input bin 68 and the output bin 88. The first waall of the intermediate bin at the compression station 94 includes a movable wall 96. The movable wall 96 has its plane arranged parallel to or coplanar with the plane of the walls 90 and the lowering plate 70. The other wall of the V shaped trough, formed in the intermediate bin of the compression station 94, includes the conveying belt 86 which forms a part of the intermediate bin.

Referring again to FIG. 4, an upper compression ceiling 98 is fixed in location directly above in opposed relationship to the movable wall 96. The fixed ceiling 98 is coupled to the housing 28. The movable wall 96 is lowered and raised by an air cylinder 100.

The conveying belt 86 is an endless belt driven by a drive sprocket 102 and an idling sprocket 104. The drive sprocket 102 is coupled to a shaft 106 (see FIGS. 3 and 6). Hence, the drive sprocket 102 of FIG. 2 is driven by the shaft 106 as shown in FIG. 6. The shaft 106 is coupled to a crank arm 108, which crank arm 108 is driven by a motor 110 (see FIG. 5). The crank arm 108 is coupled to the motor 110 through the cam 112.

Also coupled to the shaft 106 is a timing cam 114, as shown in FIG. 6. The timing cam 114 is a generally circular member driven concentrically by the shaft 106 with the timing cam having a detent 116 at one point on its circumference. A cam follower 118 engages the cam 114, so that the cam follower 118 is actuated once per revolution of the shaft 106 by its engaging of the detent 116 of the cam 114. The cam follower 118 is coupled to actuate a switch 120, whereby the switch 120 includes an arm 122 which is in the position shown at FIG. 5. when the cam follower is resting in the detent 116 of the cam 114. The crank arm 108 of FIG. 6 is driven by the cam 112 as shown in FIG. 3, through a roller 124, as shown both at FIGS. 3 and 6.

Referring to FIGS. 4 and 5, a switch 126 is engaged by the movable wall 96 of the intermediate bin at the compressing station 94. The switch 126 is shown in FIG. 5 in the normally open position, that is, when the switch is not engaged by the movable wall actuating same when the wall is in its lowermost position.

Referring now to FIG. 7, which illustrates the rack 72 in its uppermost position as depicted in solid line format at FIG. 3, the rack 72 engages a switch 128. The arm 130 of the switch 128 is shown in FIG. 5 in the position when the switch 128 is so activated, i.e., when the rack 72 is at its uppermost position.

When the rack 72 is at its lowermost position, the rack 72 engages a switch 132, as depicted at FIG. 8, and as shown in dotted line format at FIG. 3. The switch 132, in a preferred form is a double pole throw switch as depicted in FIG. 5. The switch 132 is depicted at FIG. 5 in its actuated condition.

Thus, signatures 12--12 can be indexed from the input bin 68 to the intermediate station 94 and to the output bin 88, along a line perpendicular to the incoming path of the signatures. Hence, the imaginary point on the signatures 12--12 travels in a locus lying in a plane perpendicular to the single plane which was formed in its path along the arrow indicated A. This second path, as indicated by the arrow labelled B, is perpendicular to the first path.

Automatic sequencing means are provided including electrical circuitry 134, as shown in FIG. 5, in which a latching relay is provided. The latching relay mechanism is schematically illustrated as a flip flop 136 (bi-stable device well known to those in the art) and an AND gate 138 (a well known device which provides an output upon the coincidence of signals present at all of its inputs).

Referring to FIG. 5, a D.C. voltage source 140 (diagramatically shown as coming from a battery but may, of course, come from any other voltage supply) is coupled to the arms 142 and 144 of the double pole switch 132. Another power supply 146 (which again may be a battery or a power source, and may in a specific version of this invention be the same power supply as that of the power supply 140) is coupled via a line 148 to the arm 130 of the switch 122, to the arm 144 of the switch 132, and to one input 150 of the AND gate 138. The activated terminal of the switch 128 is coupled to the S or set input of the flip flop 136. The activated terminal D of the switch 132, to which the arm 144 is now coupled, is coupled to the R or reset terminal of the flip flop 136. The activated terminal which is coupled to the arm 142 of the switch 132 is connected by a line 152 to one side of the motor 110. The unactivated terminal of the switch 132, which is now uncoupled to the arm 142, is coupled to the arm 122 of the switch 120 by means of a line 154. The other side of the motor 110 is coupled to the normally closed terminal of the switch 126 by means of a line 156. The arm 158 of the switch 126 is coupled to a line 160 to a point of reference potential, such as ground. The line 152, which is coupled to the motor 110, is coupled to a normally opened contact 162 of the switch 120. The normally closed contact 164 of the switch 120, to which the arm 122 is coupled, is coupled to an air cylinder 100 via a line 166. The air cylinder 100 is coupled via a line 168 to a point of reference potential, such as ground. The gate 138 is coupled via a line 170 to both the clutch coupling 78 and the motor 66, the other sides of the clutch coupling 78 and the motor 66 being coupled to a point of reference potential, such as ground.

In operation, the motor 16 continuously drives the driving pulley 18 via the shaft 20, so that the conveying belt continuously transports signatures, from the initial location near the printing press, toward the subsequent location indicated at 14, as shown in FIG. 1.

Assuming, in this repeating operation, that the lowering plate 70 is at its uppermost position, as depicted in FIG. 3, the switch 128 is activated as shown in FIG. 7. Thus, the switch 128, by virtue of the arm 130, provides current from the power source 146 and along the line 148 through the arm 130 of the switch 128 to set the flip flop 136. Once set, the flip flop 136 provides a constant output at its "1" terminal thereof. The "1" terminal from the flip flop 136 is coupled to the other input 172 of the gate 138. The power source 146 via the line 148 continuously applies an enabling input to Jhe terminal 150 of the gate 138. Hence, with enabling signals present at both the inputs 150 and 172 of the AND gate 138, an output is continuously provided along the line 170. The output along the line 170 thus activates both the motor 66 and the clutch coupling 78.

With the motor 66 activated, signatures 12--12 are fed from the subsequent location 14 about the arcuate path determined by the belts 32 and 34, upward along a 45.degree. angle towards the left, as shown in FIG. 1, about an arcuate path and downward towards a lower left direction.

The actuation of the clutch 78 causes the drive motor 76 to lower the rack 68. Hence, the lowering plate 70 gradually lowers to its lowermost position. As the plate gradually lowers, signatures are fed into the input bin, one on top of another, with the bottommost surface of the initially fed signature resting on the lowering plate 70, and with subsequent signatures fed thereinto aligned, one above each other. The edges of all the signatures in the input bin rest against the conveying belt 86 as a side wall thereof.

Once the lowering plate mechanism lowers, the rack 72 disengages from the switch 128. The arm 130 opens, thereby removing a signal to the flip flop 136. The flip flop 136, however, continues to provide an output from its "1" terminal. Thus the lowering plate continues to lower. When the lowering plate mechanism reaches its lowermost position, the rack 72 engages the switch 132. The switch 132 causes the arm 144 to achieve the position shown in FIG. 5 so that the current is applied from the power source 146, along the line 148, through the arm 144 of the switch 132, to reset the flip flop. Resetting the flip flop 136 removes an enabling signal from the input 172 of the gate 138, thus terminating an enabling or activating signal along the line 170, hence, disengaging the clutch 78 and halting the motor 66.

With the switch 132 activated by the rack 72, as shown in FIG. 8, the arm 142 of the switch 132 takes the position shown in FIG. 5. Hence, current is provided from the power source 140, through the arm 142, to the switch 132, along the line 152, to drive the motor 110 of the conveying mechanism. Because the air cylinder 100 in the compression station is deenergized by the actuation of the arm 142, the switch 126 activates so that the arm 158 completes the path along the line 156 to the motor 110. Hence, with the switch 132 activated, the motor 110 is driven. The motor 110 rotates so as to cause the shaft 106 to complete one revolution. As the shaft is rotating, the switch 132 opens, due to the quick return of the lowering plate 70, thus causing the switch 132 to cause the arm 142 to actuate a path along the line 154, thereby removing energizing potential from the line 152. By such action, current continues to be applied from the power source 140, through the terminal 142, through the line 154, and through the arm 122 to the terminal 162, to continue to drive the motor 110. The motor 110 continues to rotate so that the shaft 106 completes one revolution. At the end of the revolution, the cam follower 118 falls into the detent 116 of the cam 114, thereby causing the switch 120 to switch its arm 122 from the terminal 162 to the terminal 164.

Upon the switching of the arm 122 of the switch 120, the motor 110 stops, and the table chain drive halts. Furthermore, by the action of the arm 122, electric potential is applied from the power source 140 through the arm 142 of the switch 132, along the line 154, along the arm 122 of the switch 120, through the terminal 164, and, hence along the line 166 to activate the air cylinder 100. The activation of the air cylinder 100 causes the signatures at the compressing station 94 to be compressed. Coincident therewith, by the raising of the movable wall 96 at the compressing station 94, the switch 124 is activated, thus opening the arm 158 of the switch 126.

When the signatures have been conveyed away from the input bin, thereby removing its mass from the lowering plate 70, the lowering plate is rapidly driven to its uppermost position by virtue of the weight 80 which is coupled by the chain 82 to the sprocket 84 to rapidly raise the rack 72 to its uppermost position. It is noted, at this point, that the weight controls the mechanism due to the clutch coupling 78 being disengaged from the rack 72. Upon the rack 72 reaching the uppermost position, the switch 128 is engaged by the rack 72 so that the motor 76 can engage the rack again via the clutch 78.

The operation of the mechanism again repeats itself in timed relation. The signatures are continuously fed from the initial location to the subsequent location at a constant speed r.sub.1 at a rate of about from 10 to 60 feet per minute. The signatures are fed from the subsequent location and ejected into the input bin at a somewhat faster speed when the feeding mechanism is being driven. When the faster speed is indicated by an average speed r.sub.2, the feeding of the bin takes place for a loading period t.sub.1. When the signatures are bin unloaded from the input bin, the feeding of the signatures from the subsequent location to the bin is halted for a period of time t.sub.2. The relationship of the feeding times with relationship to the loading and unloading times is such that, preferably, r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1.

While the feeding mechanism is temporarily halted to permit the signatures to be unloaded from the input bin, and transported and conveyed to the intermediate bin for compressing and subsequently to the unloading bin, signatures are caused to stack up temporarily at the subsequent location 14. These signatures at the location 14 become stacked in overlapped relation at an angle indicated at FIG. 1, as somewhat of a 45.degree. angle. Upon the feeding means reinitiating and starting up again at a somewhat faster speed r.sub.2 than the transporting speed r.sub.1, the signatures are quickly transported up about the arcuate path to the input bin. During the period of halting, signatures are being grouped at the subsequent location, while others are held in the path of the conveyor belts 32 and 34, so that a signature is always gripped between the rollers 38 and 54 by the jogging mechanism 62, so that there is no wasted time in the operation of this machine.

Though for sake of clarity and illustration, a description has been made primarily of the operation of the machine for stacking signatures, it is obvious that, through techniques known to those skilled in the art, a corresponding method for stacking signatures can be performed both with the machine described and by other techniques--either by other mechanisms or by manual steps.

The use of an input bin, wherein the sides from a V shaped trough, as viewed by an observer, so that the signatures are ejected into the bin at a 45.degree. angle so that the leading edge of the signature abuts against one wall and the surface of the signatures rests against the other wall or on top of other signatures enables one to stack a greater variety of signatures, especially as to size.

Other modifications of this invention may be performed by those ordinary skilled in the art, without departing from the spirit and scope of this invention, such as, for example, the compressing station can be eliminated where not desired. The output bin can be replaced by an automatic conveying means for conveying signatures to signature packets for groups of signatures to some other location in a plant such as a bindery.

Through the practicing of this invention, either as to method or apparatus, a large variety of sizes of signatures can be handled. Also, a large "configuration" of signatures can be handled in that it is immaterial where the fold of a signature is oriented with respect to the direction of feed. Advantageously, through the use of a pusher-cleat arrangement on the conveyor, as depicted in the drawings, the operation of the apparatus can be temporarily halted and the location of the stacked signatures is precisely known.

Claims

What is claimed is:

1. Signature stacking apparatus comprising

a. an input bin adapted to receive a stack of signatures; wherein

said input bin includes a V shaped trough having a movable first wall and a second wall;

b. means for transporting a stream of overlapped signatures from an initial location toward said input bin;

c. means in cooperating relationship with said transporting means and said input bin for feeding said overlapped signatures, serially, to said input bin so as to fill said input bin with a stack of signatures,

said transporting means, said feeding means, and said input bin being so oriented so that an imaginary point on one of said signatures travels a first locus lying in a single plane;

d. an output bin adapted to receive a stack of signatures; wherein

said output bin includes a V shaped trough having a first wall parallel to or co-aligned with said input bin first wall, and a second wall co-aligned with said input bin second wall; and, when viewed along a line from one bin to another bin:

said first walls are each oriented substantially upward toward the right at a 45.degree. angle with a horizontal plane, and

said second walls are each oriented substantially upward toward the left at a 45.degree. angle with said horizontal plane; and

e. means for conveying a stack of signatures from said input bin to said output bin,

said input bin, said conveying means, and said output bin being so oriented that said imaginary point on said one of said signatures travels in a second locus lying wholly in a plane perpendicular to said single plane.

2. The signature stacking apparatus as recited in claim 1 wherein said conveying means includes said second walls.

3. The signature stacking apparatus as recited in claim 1 wherein said input bin first wall is movable along a path upward toward the left along a line oriented at a 45.degree. angle with said horizontal plane and downward toward the right along said line, wherein said input bin first wall is at its uppermost position at an initial load condition and is at its lowermost position at a full load condition.

4. The signature stacking apparatus as recited in claim 3 further comprising

f. a first driving means for said transporting means;

g. a second driving means for said feeding means;

h. a third driving means for said input bin first wall;

i. a fourth driving means for said conveying means;

j. first detecting means for sensing that said input bin first wall is at its uppermost position;

k. second detecting means for sensing that said input bin first wall is at its lowermost position; and

l. timing means in association with said first driving means, said second driving means, said third driving means, said fourth driving means, said first detecting means, and said second detecting means for causing the following sequence to take place:

1. said first driving means continuously activates said transporting means;

2. with said fourth driving means halted, and said first detecting means sensing that said input bin first wall is at its uppermost position: said second driving means activates said feeding means to feed signatures serially to said input bin to form a stack so that the bottom surface of the initially fed signature rests on the input bin first wall and an edge of each of said signatures of the formed stack rests against said input bin second wall; and said third driving means gradually lowers said input bin first wall until said input bin is full;

3. when said second detecting means senses that said input bin first wall is at its lowermost position; said second driving means is halted; said third driving means is disengaged from said input bin first wall; and said fourth driving means is indexed to transport a full stack of signatures from said input bin toward said output bin;

4. upon clearance of a full stack of signatures from said input bin, said input bin first wall is driven by said third driving means rapidly upward to its uppermost position; and;

5. upon completion of the indexing of the full stack of signatures by said fourth driving means, said fourth driving means halts, and the sequence including the steps (2) through (5) are iterated.

5. Signature stacking apparatus comprising

a. a bin for receiving a serial stream of overlapped signatures fed at the top thereof so as to form a stack of signatures within said bin;

b. a first conveyor belt, having its upper working surface oriented along a horizontal path, for transporting a multiplicity of overlapped signatures from an initial location to a second location;

c. means for continuously driving said first conveyor belt;

d. means for feeding overlapped signatures from said second location upward along an inclined path and then curving past the horizontal to eject the overlapped signatures into said bin; and

e. means (1) for halting said feeding means when said bin is full with signatures, whereby a stream of overlapped signatures continues to be fed by said first conveyor belt so that a plurality of overlapped signatures are formed in overlapping orientation at said inclined path at said second location, thus permitting a full stack of signatures to be unloaded from said bin; and (2) for driving said feeding means after said bin was unloaded so as to reload said bin with another stack of signatures.

6. The signature stacking apparatus as recited in claim 5 wherein said first conveyor belt is driven by said continuous driving means at a constant linear speed, r.sub.1 ; and wherein said feeding means is alternately driven at an average linear speed, r.sub.2, for an average load time period, t.sub.1 and halted for an average unload time period t.sub.2.

7. The signature stacking apparatus as recited in claim 6 wherein:

r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1 .

8. Signature stacking apparatus comprising `a. an input bin having a V shaped trough, said trough having a first wall oriented in an upper right direction, as viewed by an observer, forming a 45.degree. angle with the horizontal plane and having a second wall oriented in an upper left direction forming a 45.degree. angle with said horizontal plane;

b. means for moving said first wall gradually downward toward the right along a 45.degree. angle with the horizontal and rapidly upward to the left along said 45.degree. angle to form a shallow bin for receiving a few signatures when said first wall is at its uppermost position and to form a full bin for receiving a full stack of signatures when said first wall is at its lowermost position;

c. means for transporting a stream of overlapped signatures from a first location along a horizontal path toward the left to a second location;

d. means for continuously driving said transporting means so that overlapped signatures are traversed from said first location to said second location at a constant linear speed r.sub.1 ;

e. means for feeding overlapped signatures from said second location at an inclined angle upward toward the left and about an arcuate path and downward to the left, at an angle of 45.degree. with the horizontal to feed an overlapped signatures, serially, to said input bin so that the leading edge of each of said signatures abut against said second wall and wherein each of the signatures fed into said input bin operate to form a stack therewithin with the bottom surface of the bottommost signature resting on said first wall and the other signatures aligned in a stack thereabove with the leading edges of each of the stacked signatures resting against said second wall; and

f. means for alternately driving said feeding means at an average surface speed r.sub.2 for the overlapped signatures for an average duration t.sub.1 until said input bin is full, and for halting said feeding means for an average unloading period t.sub.2 to enable said input bin to be unloaded.

9. The signature stacking apparatus as recited in claim 8 wherein

r.sub.1 (t.sub.1 + t.sub.2) = r.sub.2 t.sub.1 .

10. The signature stacking apparatus as recited in claim 8 wherein said feeding means, said transporting means, and said input bin are so oriented that an imaginary point on one of said signatures travels in a first locus lying in a single plane, and further comprising

g. a V shaped output bin having a first wall oriented at a 45.degree. angle in an upper right direction with the horizontal plane, and a second wall oriented at a 45.degree. angle in an upper left direction with the horizontal plane, said first walls being oriented in either a co-planar or parallel planar relation, and said second walls being oriented in a co-planar relation; and

h. means for conveying a stack of signatures from said input bin to said output bin,

said input bin, said conveying means, and said output bin being so oriented that said imaginary point on said one of said signatures travels in a second locus lying wholly in a plane perpendicular to said single plane.

11. The signature stacking apparatus as recited in claim 10 wherein said second walls are movable within a plane parallel to said second locus plane, and said second walls are coupled to and moved by said conveying means.