GB2134891A - Apparatus for manipulating stacks of paper sheets or the like - Google Patents

Abstract

Different formats of paper stacks 2, 2' are transported seriatim along a straight horizontal path A by the upper reaches of several spaced-apart parallel endless belts 7. Some or all of the stacks are diverted from the path A onto one of two receiving conveyors 4, 6 which extend at right angles of the upper reaches of the belts. The diverting device 3 has a stop 37 which can be pivoted from above into the path of movement of a selected stack on the belts, a roller conveyor 8 which is mounted at a level below the upper reaches of the belts behind the stop and is movable upwardly so that its driven rollers pass through spaces 7a between the belts 7 and engage the lowermost sheet of the stack which has been arrested by the stop and move the stack sideways, and several driven overhead belt conveyors 31 which are mounted at a level above the path of stacks on the belts 7 behind the stop 37 and can be lowered so that their lower reaches engage the topmost sheet of the arrested stack and cooperate with the rollers 8 in transferring the stack onto the one or the other receiving conveyor 4, 6. <IMAGE>

Description

SPECIFICATION Apparatus for manipulating stacks of paper sheets or the like The present invention relates to improvements in apparatus for manipulating stacks of superimposed sheets, especially paper sheets.

More particularly, the invention relates to improvements in apparatus for transporting a series of stacks to a single destination, to two or more different destinations or to a selected one of two or more different destinations.

It is often necessary to divert certain stacks or all stacks of a series of identical or different stacks from their normal path into one or more different paths, for example, to divert certain stacks of a single file of two or more different formats of stacks to a first packing machine while the remaining stacks continue to advance to a second packing machine. In many instances, the diverted stacks are caused to advance at right angles to the direction of their travel toward the diverting station. This can create problems if the stacks are to be introduced into snugly fitting receptacles (e.g., cardboard boxes) because even a very slight misalignment of a relatively small number of sheets will prevent the stack from entering the receptacle or will result in deformation of sheets during introduction into receptacles and/or during transport toward the packing station.Abrupt changes in the direction of advancement of stacks are one of the primary causes of misalignment of sheets which form the stacks. Other causes of misalignment are shocks, e.g., due to rapid acceleration or deceleration, excessive inclination and a combination of such factors. The situation is aggravated if the stacks are transported in or to modern high-speed processing machines, e.g., to one or more high-speed packing machines or one or more high-speed machines for the making of steno pads, exercise books and analogous stationery products. Tightly fitting receptacles are desirable and advantageous in order to save space and material as well as to prevent the sheets of a confined stack from slipping relative to each other.

This renders it even more desirabie to ensure that each stack will reach its destination in optimum condition, i.e., so that its shape closely resembles that of a parallelepiped with adjoining sides disposed at right angles to each other.

The invention resides in the provision of an apparatus for manipulating stacks of paper sheets or the like. The apparatus comprises a transporting unit which serves to advance a series of identical or randomly or otherwise distributed dissimilar stacks in a first direction along a preferably straight elongated path and comprises a plurality of elongated components (preferably in the form of relatively narrow endless belts having upper reaches disposed in a common plane and defining the aforementioned path) which are spaced apart from one another, as considered transversely of the first direction, and novel and improved means for removing selected stacks of the series from the path.Such removing means comprises a step which is movable into and from the path to be engaged by an oncoming selected stack and to arrest such stack in a predetermined portion of the path, a first driven conveyor (e.g., a roller conveyor) which is disposed art a level below the path and serves to advance stacks in a second direction at least substantially at right angles to the first direction, means for moving the first conveyor up and down into and from engagement with the arrested stack in the predetermined portion of the path (the first conveyor comprises a plurality of stack-engaging elements which extend into the spaces between the components of the transporting unit to engage the arrested stack and to move such stack in the second direction in the raised position of the first conveyor), a second driven conveyor which is disposed at a level above the path and serves to advance stacks in the second direction, and means for moving the second conveyor down and up into and from engagement with the arrested stack.

The elements of the first conveyor are or can include rollers, and the second conveyor preferably comprises several endless belts. The stop is preferably pivotable into and from the path, and the removing means preferably further comprises means for pivoting the stop between first and second end positions in one of which the stop extends transversely of and is located in the path and in the other of which the stop is retracted so that it does not interfere with advancement of stacks beyond the predetermined portion of the path.

The means for moving the first conveyor up and down preferably comprises a frame (e.g., a horizontal table for several rows of coaxial driven rollers) and displacing means for moving the frame and the elements of the first conveyor up and down. The means for moving the second conveyor also comprises a frame and displacing means for moving the frame down and up. The two displacing means are discrete assemblies but are preferably analogous; for example, each such displacing means can comprise a pair of pivotable levers which are secured to the respective frame and fluid-operated (preferably pneumatic) motor means for pivoting the leversl. The means for moving the stop preferably also comprises one or more pivotable levers and means (e.g., a fluidoperated motor) for pivoting such lever or levers.

The stop can be adjustably secured to fixed carrier means so that it can pivot relative to such carrier means, e.g., in response to actuation of the aforementioned motor. The stop is preferably adjustable in the first direction so that it can intercept shorter or longer stacks in optimum positions with reference to the first and second conveyors. To this end, the stop can be provided with an elongated slot and the means for adjustably securing the stop to its carrier means can comprise a bolt, a screw or a like fastener which is provided on or is connectable with the carrier means and extends through a selected portion of the slot.

The frame for at least one of the two conveyors can be designed to move, within limits, in and counter to the first direction; this enables the removing means to properly engage shorter or longer stacks.

At least one third conveyor can be provided to receive selected stacks from the first and second conveyors and to advance the thus received stacks in or counter to the second direction.

The novel features which are considered as characteristic of the invention are set forth in particular in the appended claims. The improved apparatus itself, however, both as to its construction and its mode of operation, together with additional features and advantages thereof, will be best understood upon perusal of the following detailed description of certain specific embodiments with reference to the accompanying drawing.

FIG. 1 is a somewhat schematic plan view of an apparatus which embodies the invention and comprises two receiving conveyors; FIG. 2 is a transverse vertical sectional view as seen in the direction of arrows from the line Il-Il of FIG. 1; and FIG. 3 is a vertical sectional view as seen in the direction of arrows from the line Ill-Ill of FIG. 1.

Referring to FIG. 1, there is shown an apparatus which serves to transport a series of identical stacks 2 or 2' or a series of randomly or regularly distributed stacks 2 and 2' of paper sheets along an elongated path which is defined by a transporting unit 1. This transporting unit can be constructed and assembied in a manner as disclosed, for example, in German Offenlegungsschrift No. 32 14 350, i.e., it can comprise means for accumulating or gather successive stacks 2, 2' into a series of abutting stacks and means for thereupon singularizing the stacks so that they define gaps G of preselected width. The direction in which the stacks 2 and 2' advance along the preferably horizontal path which is defined by the transporting unit 1 is indicated by the arrow A.As can be seen in FIG. 1 , the transporting unit 1 comprises several parallel endless belts 7 which define elongated spaces 7a and extend in the direction which is indicated by the arrow A. The number of belts 7 can be reduced to two or increased to four or more. For the sake of simplicity, FIG. 1 merely shows three endless belts 7.

The novel stack removing or diverting device 3 is adjacent to an intermediate portion of the elongated path which is defined by the coplanar upper reaches of the belts 7 and serves to divert selected stacks (e.g., the larger or longer stacks 2) from such path by moving them in or counter to the direction which is indicated by an arrow B, namely at right angles to the direction of transport of stacks 2, 2' with the belts 7. The stack removing device 3 is flanked by two receiving conveyors 4 and 6 which extend at right angles to the transporting unit 1 and each of which can deliver stacks 2 to a further processing station, e.g., to a packing machine. When the removing unit 3 is idle, the stacks 2 and/or 2' are free to advance with the belts 7 beyond the receiving conveyors 4 and 6, i.e., in the direction which is indicated by the arrow A.

The stack removing device 3 comprises a first conveyor which is mounted at a level below the upper reaches of the belts 7 (five such belts are shown in FIG. 2) but is movable up toward the aforementioned intermediate portion of the path which is defined by the transporting unit 1 in order to lift a selected stack 2 off the upper reaches of the belts 7 and to advance such stack in a direction toward the receiving conveyor 4 or 6, i.e., in or counter to the direction which is indicated by the arrow B. The first conveyor comprises several rows of driven rotary elements 8 (hereinafter called rollers) whose diameters are such that they can enter the spaces 7a between neighboring belts 7 and lift a selected stack 2 off such belts in a manner as shown in FIG. 2.The means for moving the rollers 8 up and down comprises a frame 9 which constitutes or resembles a horizontal table and supports not only the shafts of the rollers 8 but also a suitable drive (not specifically shown) which can rotate some or all of the rollers in a clockwise or counterclockwise direction. Such drive can comprise a reversible electric motor and a gear train between the output element of the motor and the shafts of some or all of the rollers 8. The upper reaches of the belts 7 advance successive stacks 2, 2' in a direction toward the observer of FIG. 2, and the just discussed drive can rotate some or all of the rollers 8 about horizontal axes which extend at right angles to the plane of FIG. 2. Thus, if the rollers 8 are rotated in a clockwise direction, they can transfer a selected stack 2 onto one of the receiving conveyors 4, 6.The other of these receiving conveyors accepts stacks 2 when the rollers 8 are driven to rotate in a counterclockwise direction, as viewed in FIG. 2. The table or frame 9 further supports two endless belt conveyors (or two sets of endless belt conveyors) 16, 1 7 which are respectively trained over pulleys 11, 1 2 and 13, 1 4. The purpose of the belt conveyor or conveyors 1 6 is to accept stacks 2 from the rollers 8 (when these rollers are held in raised positions so that they are disposed at the level which is shown in FIG. 2) and to transfer such stacks all the way onto the receiving conveyor 6. The belt conveyor or conveyors 1 7 serve to accept stacks 2 from the rollers 8 and to transfer such stacks onto or into the range of the receiving conveyor 4.

The means for moving the first conveyor including the rollers 8 and the belt conveyors 16, 1 7 up and down further comprises displacing means for moving the frame 9 up and down. Such displacing means comprises at least one pair of levers 19, 21, which are coupled to each other by a link 18, and a motor 26 (preferably a pneumatic cylinder and piston unit) which can pivot the levers 19, 21 about the axes of stationary shafts 23, 24 to thereby raise or lower the frame 9, the rollers 8 and the conveyors 1 6, 1 7 thereon. It is preferred to provide two levers 19, 21 and a link 1 8 in front and two levers 19, 21 and a link 18 behind the frame 9, as considered in the direction of arrow A.

The levers 19 and 21 are pivotable with reference to a stationary housing or support 22 of the apparatus. The cylinder of the motor 26 is also articulately connected to the support 22.

The stack removing device 3 further comprises a second conveyor which is disposed at a level above the upper reaches of the belts 7 and includes one, two or more (e.g., three) endless belts 31 which are trained over pulleys 28, 29 supported in a frame 27 which constitute one part of the means for moving the conveyor including the belts 31 downwardly toward and upwardly away from the path of stacks 2, 2' on the belts 7.

The means for driving the belts 31 in the direction of arrow B (to advance the stacks 2 toward the receiving conveyor 4) or in a direction counter to that which is indicated by the arrow B (in order to advance the stacks 2 toward the receiving conveyor 6) is not specifically shown in the drawing. Such drive means can also comprise a reversible electric motor and a suitable gear, belt or chain transmission between the output element of the motor and one of the pulleys 28, 29. The means for moving the frame 27 down and up is preferably analogous to the moving means for the lower frame 9.Thus, such moving means can comprise two pairs of levers 33, 34 which are pivotably mounted in the support 22 at a level above the transporting unit 1, a link 32 between each pair of levers 33, 34, and a motor 36 (preferably a fluid-operated cylinder and piston unit) which can pivot the levers 33, 34 relative to the support 22 to thereby lower the frame 31 toward or to lift the frame 31 above and away from the upper reaches of the belts 7.

Still further, the stack removing device 3 comprises a stop 37 extending transversely of the direction which is indicated by the arrow A and mounted at a level above the upper reaches of the belts 7. This stop is movable into and from the path of movement of selected oncoming stacks 2 or 2' to arrest a selected stack in the aforementioned intermediate (predetermined) portion of the path preparatory to engagement of such selected stack by the rollers 8 (from below) and the belts 31 (from above). When the stop 37 is ready to arrest an oncoming stack 2, it is held in the solid-line position of FIG. 3. If the stacks 2 and/or 2' are to advance beyond the receiving conveyors 4 and 6, the stop 37 is pivoted to the phantom-line position of FIG. 3 so that it is located at a level above the path of the tallest stacks on the belts 7.The means for moving the stop 37 between the solid-line and the phantom-line positions of FIG. 3 includes a lever 38 which is rigidly connected with the stop and a fluidoperated (preferably pneumatic) motor 39 which can pivot the lever 38 jointly with the stop 37. The pivot 38a for the lever 38 is mounted on a bracket 41 which can be said to form part of the stop 37 and has an elongated slot 42 for a fastener 43 serving to extend through a selected portion of the slot 42 and to releasably and adjustably secure the bracket 41 to a stationary support or carrier 44, e.g., a skeleton frame on the aforementioned support 22 of the apparatus.The slot 42 extends in the direction of arrow A, and the purpose of adjustability of the stop 37 in and counter to such direction is to ensure that the stop 37 can arrest short or long stacks 2' or 2 in optimum positions for engagement by the rollers 8 from below and by the belts 31 from above preparatory to transfer of stacks onto the receiving conveyor 4 or 6.

The apparatus can further comprise means for shifting the frame 27 and its belts 31 in the direction of arrow A (i.e., at right angles to the direction of advancement of the belts 31) in order to enable the second conveyor including the belts 31 to invariably engage the center portion of the upper side of a selected stack which has been arrested by the stop 37 and is ready for transfer onto the receiving conveyor 4 or 6. Such adjustability of the frame 27 can be readily achieved by mounting the latter on a carriage which is shiftable within limits relative to the support 22 in and counter to the direction of arrow A.

The operation is as follows: If the stacks 2 are to be transferred seriatim onto the receiving conveyor 4, the rollers 8 are driven so that they rotate in a clockwise directior, as viewed in FIG. 2, and the belts 31 are driven so that their lower reaches advance in the direction of arrow B, as viewed in FIG. 1. The motor 39 is actuable by a suitable sensor (e.g., a photoelectric cell) which monitors the path for the presence of longer stacks 2 and transmits appropriate signals to the valve or valves which control the flow of pressurized fluid into and the evacuation of fluid from the chambers of the cylinder forming part of the motor 39.The stop 37 is pivoted to operative position while a gap G is located therebelow so that the stop moves into the path of movement of the leading edge of the oncoming stack 2 and arrests the stack in an optimum position for engagement by the rollers 8 (from below) and by the lower reaches of the belts 31 (from above). For this purpose, the actuating means for the motors 26 and 36 can be operated with a preselected delay following actuation of the motor 39 so that the rollers 8 enter the spaces 7a between the belts 7 and the belts 31 engage the topmost sheet of the stack 2 which abuts against the stop 37. The stack is then automatically moved sideways into the range of the belts 1 7 which complete the transfer of the stack onto the conveyor 4.

If the stacks 2 are to be transferred onto the receiving conveyor 6, the direction of rotation of the rollers 8 and the direction of movement of the lower reaches of the belts 31 is reversed. The operation can be fully automatic, or it can be automated to a desired extent. It is also possible to alternately transfer stacks 2 or 2' onto the conveyors 4, 6; to transfer a first number of stacks 2 or 2' onto the conveyor 4, thereupon a different second number of stacks 2 or 2' onto the conveyor 6, a first number of stacks 2 or 2 onto the conveyor 4, and so forth. Still further, it is possible to transfer stacks 2 onto the conveyor 4 and to transfer stacks 2' onto the conveyor 6, or vice versa.

It has been found that the combination of stop 37, belts 31 and rollers 8 ensures a highly predictable transfer of stacks from the transporting unit 1 without any shifting of sheets within a stack so that the transferred stacks can be readily introduced into fitting receptacles or that they can be further processed into stationery products or the like. The stability of a stack which is about to be transferred or which is being transferred is ensured by the stop 37 and belts 31; the rollers 8 lift the stack off the upper reaches of the belts 7 and assist the belts 31 in moving the lifted stack sideways. If the apparatus is to transport a single type of stacks or two or more different types of stacks along the path which is defined by the upper reaches of the belts 7 and all the way to the station at the discharge end of the transporting unit 1 , the stop 37 is maintained in the inoperative position, the frame 9 for the rollers 8 is held in its lower end position, and the frame 27 for the belts 31 is maintained in its upper end position.

Claims (16)

1. Apparatus for manipulating stacks of paper sheets or the like, comprising a transporting unit arranged to advance a series of stacks in a first direction along an elongated path and comprising a plurality of elongated components which are spaced apart from one another, as considered transversely of said path; and means for removing selected stacks of said series from said path, including a stop movable into said path to arrest an oncoming selected stack in a predetermined portion of said path, a first driven conveyor disposed at a level below said path and arranged to advance stacks in a second direction substantially at right angles to said first direction, means for moving said first conveyor up and down into and from engagement with the arrested stack in said portion of said path, said conveyor having a plurality of stack-engaging elements which extend into the spaces between said components to engage the arrested stack and to move the latter in said second direction in the raised position of said conveyor, a second driven conveyor disposed at a level above said path and arranged to advance stacks in said second direction, and means for moving said second conveyor down and up into and from engagement with the arrested stack.

2. The apparatus of claim 1, wherein said components are parallel endless belts having upper reaches disposed in a common plane and defining said path.

3. The apparatus of claim 1, wherein said elements are rollers.

4. The apparatus of claim 1, wherein said second conveyor comprises a plurality of endless belts.

5. The apparatus of claim 1 , wherein said stop is pivotable into and from said path, and further comprising means for pivoting said stop.

6. The apparatus of claim 1 , wherein the means for moving said first conveyor comprises a frame for said elements and means for moving said frame up and down.

7. The apparatus of claim 1, wherein said means for moving said second conveyor comprises a frame and displacing means for moving said frame down and up.

8. The apparatus of claim 7, wherein said means for moving said first conveyor includes a frame for said elements and discrete second displacing means for moving such frame up and down, said second displacing means being analogous to the displacing means for moving said first named frame.

9. The apparatus of claim 8, wherein each of said displacing means comprises pivotable lever means secured to the respective frame and fluidoperated motor means for pivoting the lever means.

1 0. The apparatus of claim 9, wherein each of said motor means comprises a pneumatic motor.

11. The apparatus of claim 1, further comprising means for moving said stop into and from said path, including pivotable lever means rigidly connected with said stop and means for pivoting said lever means.

12. The apparatus of claim 11, wherein said pivoting means comprises a fluid-operated motor.

13. The apparatus of claim 1 ,further comprising carrier means for stop, means for adjustably securing said stop to said carrier means, and means for moving said stop with reference to said carrier means.

14. The apparatus of claim 13, wherein said stop is adjustable with reference to said carrier means, as considered in said first direction.

1 5. The apparatus of claim 13, wherein said stop has an elongated slot and said securing means comprises fastener means provided on said carrier means and extending through a selected portion of said slot.

16. The apparatus of claim 1, wherein the moving means for said second conveyor comprises a frame for said second conveyor and means for moving said frame within limits in and counter to said first direction.

1 7. The apparatus of claim 1, further comprising a third conveyor arranged to receive selected stacks from said first and second conveyors and to advance the thus received stacks in said second direction.

1 8. Apparatus for manipulating stacks of paper sheets or the like, substantially as herein described with reference to the accompanying drawings.