GB2028285A - Apparatus for discharging piles from a counting store - Google Patents

Abstract

Apparatus is disclosed for advancing side-by-side streams of sheets 3 into stacks 7 and discharging each stack onto a continuously moving conveyor, eg. belts 33, when it contains a required number of sheets. The sheets 3 are supplied side-by-side on conveyor 2 to side-by-side temporary holders 4 which subsequently drop the sheets into stacks 7 held on supports 32. A counter 74 is associated with each sheet line. When a required number of sheets has passed through a particular line, the stack supports 32 and belts 33 are moved adjacent each other and an associated pusher 52 for the line pushes the associated stack onto the belts. <IMAGE>

Description

SPECIFICATION Apparatus for discharging piles from a counting store The invention relates to an apparatus for discharging piles of sheets of paper or similar material from a counting store, which comprises several holders arranged side-by-side for the rows of paper sheets or layers of paper sheets which can be supplied by a supply conveyor, the number of rows corresponding to the number of holders, by means of a discharge conveyor supporting the piles, for which a counting device is associated with the counting store for counting the paper sheets or layers supplied to the holders and a drive which can be controlled by the counting device is associated with the discharge conveyor.

In a known apparatus of the said type, the base of the holders of the counting store is formed by conveyor belts, which on reaching the desired height of the piles are accelerated gently together from a standstill and after a short distance the piles are discharged to continuously rotating conveyor belts.

In this case, the conveyor belts forming the base of the holders should only be driven until the next sheets or layers for forming the next pile are deposited or these sheets or layers should only be deposited when the conveyor belts have discharged the piles from the holders and transferred them to the associated conveyor belts. This considerably limits the capacity of such an apparatus, since the conveyor belts conveying the piles from the holders must be accelerated relatively gently, in order that the piles are not deformed by the acceleration, which is troublesome at the time of further processing or necessitates an additional alignment device. In the case of relatively high piles, there is even a danger that they are completely deformed in the case of excessive acceleration.The acceleration of the conveyor belts could certainly be optimised by incurring expenditure for control electronics, but this would make the apparatus very expensive, especially in relationship to the object to be solved by this invention.

In the known apparatus, a further problem is produced by the common discharge of all piles of one row from the holders. The discharge is initiated in this case by means of a counter driven by the machine cycle or supply conveyor cycle or counting the paper sheets or layers in one row of the supply conveyor. However, if a sheet or layer is missing in a row (which is not monitored), which frequently occurs, then an incomplete pile is formed and discharged.

The object of the invention is to provide an apparatus of the afore-mentioned type, which is capable of high production, with the least possible expenditure, by which piles each with a definite number of sheets of paper or layers can be formed and discharged quickly.

This object is fulfilled according to the invention due to the fact that a continuously rotating conveyor for the piles is located below each holder, that associated with each holder is a separate control arrangement for moving support means for receiving the piles and the conveyors towards each other and that associated with each holder is an individual counting device which is connected to a drive for the support means of the respective holder.

The following advantages are achieved by the invention: the separate control of the transfer of piles to the conveyors by way of associated separate counting devices ensures the formation of piles with a definite number of sheets, even if gaps occur in the flow of paper sheets or layers supplied. Moving the support means and conveyers towards each other is less expensive to achieve as regards construction and drive. Since the support means are intended to protect the piles solely from premature contact with the conveyers, whilst the piles are being received, the support means can be located at a slight distance above the conveyors.This facilitates relatively slow deposition of the piles on the conveyors in a short time, so that the conveyors firstly slip under the piles, whereupon due to a continuous reduction of the slip, the piles are accelerated and transferred gently and without changing their shape, by the conveyers. With the invention, separate drives for the conveyers, which were otherwise necessary, for the independent discharge of the piles from the holders, are eliminated.

In a further embodiment, conveyors which are particularly suitable for the afore-described transfer of the piles from the support means to the conveyors are those which comprise several conveyor belts guided in parallel and at a distance apart and support means which comprise fork-like recesses for the conveyor belts.

In a preferred embodiment of the invention illustrated in the drawings, each holder comprises separately controllable support means for receiving and then lowering the piles to the associated conveyers. However, variations are still within the scope of the invention, in which the conveyors for receiving the piles are raised in the direction of the support means or both the support means as well as the conveyors are moved towards each other.

Also, the afore-described apparatus is naturally limited in its output, because from a certain speed of the continuously rotating conveyers, the slip firstly occurring at the time of the transfer once more leads to a deformation of the piles. In orderto increase the production capacity of the afore-described apparatus, according to a particularly advantageous embodiment of the invention, it is provided that associated with each holder is a push rod which can be set in a translatory motion by a drive, for accelerating the piles in the feed direction of the conveyors and that a control member associated with each pushrod, for initiating a movement of the push rod is connected to the counting device associated with the respective holder.Also, this further embodiment can be carried out with relatively low expenditure, in that according to a further feature, each pushrod can be driven by means of a coupling member by a control cam, the control cams for all the pushrods can be driven continuously in synchronism with the feed cycle of the supply conveyor and associated with each pushrod is a locking device which can be released by the control member, which keeps the pushrod in an initial position.The combination of support means which can be lowered, for transferring the piles to the conveyors and pushrods for accelerating the piles in the feed direction of the conveyors necessitates only a relatively short stroke of the pushrod for the purpose of acceleration, because the pushrods are not intended to bring about full acceleration of the piles, since in the manner afore-described, when the piles are delivered to the conveyors, part of the acceleration can be provided by the conveyors themselves. When the piles have left the holders, the pushrods are consequently returned to their initial position, so that the return stroke of the pushrods is not wasted as if the piles were pushed out of the holders exclusively by means of the pushrods.Accordingly, according to a further feature, the drives or displacements of the support means and pushrods are synchronised with respect to each other so that the pushrods accelerate the piles before the support means deliver the piles to the conveyors.

The invention is described in detail hereafter with reference to the drawings illustrating one embodiment: Figure 1 is a sectional view on line I-I of Figure 2 of an apparatus for forming and discharging piles of layers of paper, Figure 2 is a plan view of the apparatus on line ll-ll of Figure 1.

A supply conveyor 2 comprising multiple paths for layers 3 shrunk in a film, leads from a shrinkage tunnel 1 to several holders 4 arranged side-by-side, below which controllable support means 6 for receiving piles 7 formed from layers 3 are respectively located, the support means 6 being components of a discharge conveyor 8 for the piles 7. The supply conveyor 2 consists of a plurality of conveyor belts 14 guided in parallel side-by-side around guides in the form of rollers 9, 11 and 12 and around a continuously driven drum 13. The holders 4 are formed respectively by controllable pairs of support bars, consisting of a first support bar 16a and a second support bar 1 6b, the first support bars 16a being screwed into a first support 17a and the second support bars 16b being screwed into a second support 17b.

The front support 17b is located below the roller 11 of the supply conveyor 2. By providing a plurality of mounting bores 18a and 18b (shown in dot-dash lines) in the supports 17a, 17b, the spacing of the support barts 16a and 16b respectively forming a holder 4 can be adapted to different formats of the layers 3. Also, by removing the outer support bars 16a and shifting the remaining inner support bars 16a into the position shown in dot-dash line and by removing the outer suppor bars 16b it is possible to form two holders 4' for relatively wide layers 3' (drawn in dot-dash lines), in place of the illustrated four holders 4 for the relatively narrow layers 3.

Naturally, by suitable re-grouping and removal and/or addition of bars 16a and 16b, it is possible to form 3,5 or 6 or even more holders 4.

In place of the afore-mentioned mounting bores 18a and 18b in the supports 17a, 17b, the support bars may also be provided with clamping members which allow a continuous lateral displacement.

Provided above the rear bars 1 6b and in front of the rear support 17a is a stationary stop 19 for the layers 3, which forms a common end wall for all the holders 4. The two supports 17a and 17b are interconnected by means of two levers 21a and 21 b to form a tilting parallelogram, the levers 21 a and 21 b being mounted to pivot respectively centrally about stationary pivots 22a, 22b. Engaging the lever 22a is a pivot drive 23, which consists of a pneumatic cylinder 26 able to pivot about a pivot 24, whereof the piston rod 27 is connected to a lever 28 connected in a non-rotary manner to the lever 22a.

Each support means 6 for receiving a pile 7 formed from the layers 3 consists of two bars 31, arranged transversely with respect to the direction in which the piles 7 are discharged, which bars 31 comprise recesses 32 for a conveyor in the form of several conveyor belts 33 guided parallel to each other and belonging to the discharge conveyor 8 and supporting guide plates34forthe latter in the region ofthe support means 6 and which are respectively attached to a support 36.

Each support 36 is mounted by means of pivots 37a and 37b on levers 39a, 39b able to pivot about stationary pivots 38a and 38b, each lever 39b being connected to a separate pivot drive 41, which consists respectively of a cylinder 43 able to pivot about a pivot 42, the piston rod 44 of which is connected to a lever 46 connected in a non-rotary manner to the lever 39b.

The conveyor belts 33 of the discharge conveyor 8 are guided around rollers 47 and 48 as well as around a continuously driven drum 49. Also belonging to the discharge conveyor 8, for each holder 4, is a push rod 51, whereof the pushrod plates 52 form the rear walls of the holders 4 and whereof the rods 53 are guided in a frame 54 and acted upon by a compression spring 56. Each push rod 51 comprises its own drive 57, which consists respectively of a coupling member in the form of a lever 59 able to pivot about a stationary pivot 58 and of a control cam 61, each lever 59 being connected at one end to a rod 53 and at its other end supporting a roller 62, which rolls on the associated control cam 61.

Associated with each lever 59 is a locking device 63, whereof the ratchet 64 is able to pivot about a pivot 68 by means of an armature 66 of a control member in the form of an electromagnet 67, the ratchet 64 releasing a stop 69 on the lever 59 so that the compression spring 56 is able to move the pushrod 51 in the direction of arrow 71 according to the shape of the control cam 61. All the control cams 61 are attached to a common shaft 72, which is driven in synchronism with the feed cycle of the supply conveyor 2, i.e. it carries out a full revolution in the direction of arrow 73 for each feed cycle (supply of one row of layers 3).

A monitoring device for the supply of layers 3 in the form of a reflection light barrier 74 is provided in front of the roller 11, above the supply conveyor 2 for each holder 4. These light barriers 74 are connected so that they emit a signal when their light rays are no longer reflected by a layer 3, i.e. the light barriers 74 monitor the rear edges of the layers 3. The light barriers 74 are followed by a time-lag member 75. All the light barriers 74 are respectively connected by way of a lead 76 to an OR-gate (not shown) the output of which is connected to a control device (likewise not shown) for the pneumatic cylinder 26.

Each light barrier 74 is also connected to a counting device in the form of an adjustable counter 77, the output of each counter being connected to a setting input of an associated flip-flop member 78. A cancellation input of each flip-flop member 78 is respectively connected to a limit switch 79, which is associated with the respective support 36 of the support means 6 of the associated holder 4. The output of each flip-flop member 78 is connected by way of an amplifier 81 to an electro-pneumatic valve 82, which connected the respective pneumatic cylinder 43 to a source 83 of compressed air and to the electromagnet 67 associated with each holder.

Together with the associated counter 77, the flip-flop member 78, the amplifier 81, the valve 82 and the pivot drive 41, each light barrier 73 forms a control arrangement 80 for moving the support means 6 and conveyors 33 towards each other.

Mechanical drives such as those for the pushrods 51 may naturally also be used in place of the pneumatic drives for the support means 6.

The apparatus operates as follows: the layers 3 are conveyed in rows of four side-by-side on the supply conveyor 2 from the shrinkage tunnel 1 to the holders 4, where the layers 3 are stopped by the stop 19 and come to lie on a support bar 16a and 16b in the vicinity of their side edges. A signal emitted by the reflection light barriers 74 is delayed by the time-lag members 75 until the layers 3 have reached their end position against the stop 19 in a reliable manner. The delayed signals then activate the pivot drive 23, i.e. due to a corresponding supply of compressed air, the pneumatic cylinder 26 retracts its piston rod 27, so that by way of the lever 28, the parallelogram of levers 21a and 21 band the supports 17a and 17b is tilted in a corresponding manner.In this case, the support bars 1 6a and 1 6b move away from each other to an extent such that they release the layers 3 and the latter drop onto the bars 31 ofthe support means 6 or onto the layers 3 in the holders 4 already resting on the latter. Then, due to a corresponding supply of compressed air and venting, the pneumatic cylinder 26 then once more extends its piston rod 27, due to which the levers 21 a and 2land the supports 17a and 17b are swung back into their initial position, in which the support bars 16a and 16b are once more able to receive a row of layers.

The signal from each reflection light barrier 74 is also supplied to the respective associated counters 77, which after reaching a pre-set number, send a control signal to the subsequent flip-flop members 78. After a signal of this type is sent to one of the flip-flop members 78, a signal appears at its outputs which, amplified by the amplifier 81, is supplied both to the electropneumatic valve 82 as well as to the electromagnet 67 and excites the latter. The electropneumatic valve 82 changes its switching state, so that the support 36 mounted on the levers 39a and 39b is tilted downwards by retracting the piston rod 44 in the pneumatic cylinder 43, which takes place relatively slowly due to a corresponding adjustment of a restrictor associated with the cylin der43.

The excitation of the electromagnet 67 results in a retraction of its piston rod 66, which means that the ratchet 64 is tilted about the pivot 68 in counterclockwise direction. The stop 69 on the lever 59 is now released so that the compression spring 56 can move the pushrod 51 in the direction of arrow 71.

This movement is controlled by the control cam 61, on which the roller 62 of the lever 59 travels and which determines the sequence of movements of the pushrod 51.

Thus, whilst the support means 6 lower the piles 7 to the conveyor belts 33, the pile 7 is simultaneously accelerated by the pushrod plate 52 in the feed direction of the conveyor belts 33. The movement of the piston rod 44 and the shape of the control cam 61 are synchronised with respect to each other so that the pushrod 51 has reached its maximum speed when the pile 7 is placed on the conveyor belts 33.

The conveying speed of the conveyor belts 33 can be greater than the maximum speed of the pushrod 51, in which case, due to the slip which prevails at first, with gentle placing of the pile 7 on the conveyor belts 33, the pile 7 is in practice constantly accelerated to the speed of the conveyor belts 33.

On reaching its lower end position, the support 36 of the support means 6 actuates the limit switch 79, which sends a signal to the cancellation input of the flip-flop member 78, which thus alters its switching state, which means that its output signal disappears.

The electropneumatic valve 82 and the electromagnet 67 are de-excited, which has the result that on the one hand the electropneumatic valve 82 returns to its initial position and the pivot drive 41 consequently moves the support 36 once more upwards and on the other hand the ratchet 64 is brought into the engaged position. With the compression of the compression spring 56, the pushrod 51 is returned by the control arm 61 into its initial position, in which the stop 69 is engaged by the ratchet 64.

After reaching their pre-set counting state and emitting an output signal, the counters 77 begin a new counting operation corresponding to the sequence of layers 3 supplied. If gaps appear in one of the layers supplied to the four rows, then the discharge of one of the piles formed from this row takes place later, namely only when the number of layers 3 set at the respective counter 77 has been supplied to the corresponding holder. With a corresponding adjustment of the counters 77, it is consequently possible to form piles 7 of different size side-by-side.

In a variation which is not illustrated, the support means 6 may be arranged to be stationary and the guide plates 34 for the conveyor belts 33 may be attached to the support 36, in which case the valve 82 is exchanged for valve operating in the opposite direction. In this variation, the transfer of piles 7 takes place by raising of the conveyor belts 33.

Claims (7)

1. Apparatus for discharging piles of sheets of paper or similar material from a counting store, which comprises several holders arranges side-byside for rows of sheets or layers of sheets which can be supplied by a supply conveyor, the number of which rows corresponds to the number of holders, by means of a discharge conveyor supporting the piles, for which a counting device is associated with the counting store for counting the sheets of paper or layers supplied to the holders and a drive able to be controlled by the counting device is associated with the discharge conveyor, wherein, located below each holder is a continuously rotating conveyor for the piles, associated with each holder is a separate control arrangement for moving support means for receiving the piles and the conveyors towards each other and associated with each holder is an individual counting device which is connected to a drive for the support means of the respective holder.

2. Apparatus as claimed in claim 1, wherein each conveyor comprises a plurality of conveyor belts guided in parallel and at a distance apart and the support means comprise fork-like recesses for the conveyor belts.

3. Apparatus as claimed in claim 1 or 2, wherein each holder comprises separately controllable support means for receiving and subsequently lowering the piles to the associated conveyors.

4. Apparatus as claimed in any one of the preceding claims, wherein associated with each holder is a pushrod which can be set in a translatory movement by a drive, for accelerating the piles in the feed direction of the conveyors and a control member for initiating a movement of the pushrod, associated with each push rod, is connected to the counting device associated with the respective holder.

5. Apparatus as claimed in claim 4, wherein each pushrod can be driven by means of a coupling member by a control cam, the control cams for all the push rods can be driven continuously in synchronism with the feed cycle of the supply conveyor and associated with each pushrod is a locking device which can be released by the control member, which keeps the pushrod in an initial position.

6. Apparatus according to any one of the preceding claims, wherein the drives or the displacements of the support means and pushrods are synchronised with respect to each other so that the pushrods accelerate the piles before the support means deliver the piles to the conveyors.

7. Apparatus for discharging piles of sheets of paper or similar material from a counting store, substantially as herein described with reference to and as illustrated in the accompanying drawings.