GB1574895A

GB1574895A - Apparatus for depositing sheets

Info

Publication number: GB1574895A
Application number: GB21919/78A
Authority: GB
Original assignee: Bielomatik Leuze GmbH and Co KG
Current assignee: Bielomatik Leuze GmbH and Co KG
Priority date: 1977-06-24
Filing date: 1978-05-24
Publication date: 1980-09-10

Description

(54) APPARATUS FOR DEPOSITING SHEETS (71) We, BIELOMATIK LEUZE & cho., a body corporate organised under the laws of the Federal Republic of Germany, of Max-Planck-Strasse 15, 7442 Neuffen, Federal Republic of Germany, do hereby deolare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- The invention relates to an apparatus for depositing sheets in a stack and for carrying off the stack with a depositing table which may be raised and lowered, whence the stack may be carried off by means of a conveyor.

An apparatus of the kind referred to above has been proposed in which a stream of sheets shed on a supplying stretch may be passed selectively on to two different depositing tables by means of a switch. While the stack is formed on one table, the previously formed stack is carried off from the other depositing table. However, complicated lifting and lowering devices are required for carrying off the stack or the ream at a predetermined level.

In addition, two different stacking tables are required and this increases the cost of the apparatus.

A depositing apparatus is also known from German Auslegeschrift No. 1 303 445 in which an auxiliary stop, for example, in the form of a blade is introduced into the stream ob sheets in the region of the rear wall of the depositing table in order to support the rear end of the stack being formed while the stack thereunder is grasped and carried off by a gripper.

An object of the invention is to provide a deposing apparatus for forming a stack or a ream in which a continuously arriving stream of sheets may be deposited on a depositing table and be carried off from it without wastage.

According to the invention there is provided an apparatus for depositing sheets in a stack and for carrying off the stack, comprising a depositing table, having a conveyor for carry ,ing off a stack of sheets, means for raising and lowering the said table, a preliminary collecting section arranged upstream of the said table, and a separating device selectively insertable into the path of sheets travelling from the preliminary collecting section to the said table for temporary preliminary collection of sheets while a stack of sheets is carried off from the depositing table.

Therefore, although the previously formed stack is carried off by the depositing table, a smaller stack is formed on the preliminary collection section and is then transferred as such on to the depositing table and the remainder of the stack is then formed on it. It is particularly advantageous if the stack on the preliminary collecting section is kept as small as possible, that is to say the period until the stack is carried off by the depositing table is kept as small as possible. For this purpose, a preferred embodiment of the invention proposes that a carrying off section which is provided with a conveyor and can be raised and lowered at least in part together with the depositing table follow the depositing table.

When the stack is formed, then the depositing table has read its lower position.

If the conveyor which conveys the stack from the depositing table therefore starts up now, the depositing table can already be driven upwards again. The stack is thus transferred on to the carrying off section which rises together with it at least in the region adjacent to the depositing table. The carrying off section, like the depositing table, preferably has belts arranged horizontally in succession which may be actuated both simultaneously and independently ob each other. However, it would alternatively be possible to allow only the front section of the carrying off belt to rise and and descend so that it forms a ramp. This could however give rise to disadvantages because the stack could slip in the case of in dined transportation. When the depositing table has reached its upper position again, the separating device, for example a stop which may be pivoted into the stream d sheets from above, is pivoted out again and the previously collected stack is conveyed as a unit on to the depositing table and there aligned by beater plates or the like. The stack begins to form again while the stack is in the meantime conveyed by the carrying off device to the subsequent transporting stretch.

Other advantages and features of the invention are derived from the sub-claims and the following description in conjunction with the drawings. An embodiment of the invention is shown schemarically in the drawing and is described in more detail below.

In the accompanying drawings: Figs. 1 to 3 show in a schematic side view three operating positions of the apparatus according to the invention.

The apparatus shown in the drawings is used for forming a stack or preferably a socalled ream of sheets made of flat material, in particular paper, and normally forms part of a paper manufacturing or processing machine.

An apparatus for forming a stream of overlapping sheets is normally arranged upstream of this apparatus. The stream of overlapping or staggered sheets 11 lying one on top of the other is continuously supplied from this apparatus by supplying conveyor belt 12 to the depositing apparatus. The sheets run on to a preliminary collecting section 13 which, in the embodiment shown, has a conveyor in the form of a conveyor belt 14 driven by a drive mechanism 15. The preliminary collecting section is provided with a separating device 16 in the form of a pivotally mounted stop which is pivotal between a passage position (Figs. 1 and 3) and a separating position (Fig. 2) in which it prevents the stream d sheets from passing.

The apparatus also has a lowerable stacking table 17 which may be lowered and raised again by a lifting and lowering apparatus 18 known per se. The lifting and lowering appara 18 is shown as a hydraulic cylinder but can function in some other manner, for example by means of toothed racks.

The lowerable stacking table is provided with a depositing table 19 and a carrying off section 20. In the example shown, both have conveyor belts 21, 22 which are each driven by a drive mechanism 23, 24. The conveyor belts can be driven selectively either together or independently of each other. Only lower belts are shown in the drawing for simplification. In practice, synchronously driven upper belts are preferably also present, the stack or stream of sheets being clamped between the upper and lower belts.

A stop 25 is arranged above the downstream end of the depositing table. The stop 25 may be moved up and down vertically in a guide mechanism shown diagrammatically. This stop limits the downstream end of the stack 26 which forms on the depositing table. This stop can be of any desired type; for example it can be pivotal or designed to be driven out to the side. The stack is limited on both sides, for example, on one side by a fixed baffle and on the other side by a so-called beater plate which vibrates in order to align the stack. The depositing table and the carrying off section 19, 20 lie in the upper position of the lowerable stacking table which is shown in Fig. 3 at about the height of the preliminary collecting section 13. At this heighr, the carrying off section 20 is followed by a carrying off stretch 27 shown in the form of another conveyor belt.

The stream of sheets arriving on the supplying conveyor belt 12 is passed during normal formation of the stack (Fig. 1) via the preliminary collecting section 13 whose conveyor belt runs as indicated by the arrow and thus acts simply as an extension of the supplying conveyor belt. The sheets 11 strike the stop 25, are aligned there and form the stack 26 lying on the depositing table 19 which is lowered by the lifting and lowering device 18 as the stack grows. The conveyor, that is to say the conveyor belt driven by the drive mechanism 23, remains stationary as does that of the carrying off section 20. The separating device 16 is pivoted from the path of the stream of sheets.

Fig. 2 shows an operating position in which the formation of the stack has just ended and the lowerable stacking table 17 is located in its lower position. The conveyor belt of the preliminary collection section 13 is now stop ped and the separating device 16 simultaneously pivoted into the stream of sheets 90 that it forms a temporary stop for the sheets 11. The conveyor belt 21 of the depositing table 19 is simultaneously driven by the drive mechanism 23 once the stop 25 has been driven upwards from the rear edge of the stack. The belt 22 of the carrying off section 20 is started up by its drive mechanism 24 so that the stack 26 is carried from the depositing table 19 on to the carrying off section 20. However, as soon as the continued flowing of the stream of sheets through the separating device 16 is interrupted, the lowerable stacking table with depositing table and carrying off section begins to rise so that the stack 26 can be conveyed on to the carrying off section in this period. A small stack 28 which can be kept very small owing to the shortness of the time required for carrying off the stack 26, is formed in the meantime upstream of the separating device 16. If the sheets arrive at very high speeds or if they are very thick, it would of course also be possible, as shown in broken lines in Fig.

2, to make the preliminary collecting section 13 lowerable by a lifting and lowering device 29 so as to be able to form the small stack 28 satisfactorily.

Fig. 3 shows an operating position which exists shortly after the moment at which the stack 26 has finally left the conveyor belt 21 of the depositing table, the stop 25 has been driven down again and the lowerable stacking table has entered its upper operating position.

At this moment, the belt 21 od the depositing table 19 is stopped, the spearating device 16 is pivoted out and the conveyor belt of the preliminary collecting section 13 started up again. It should be noted that the small stack 28 is now transferred on to the depositing table and there pushed against the stop 25.

A variation of this mode of operation is possible in which the conveyor belt 21 continues to be driven for a sufficiently long period for the stack 28 to strike the stop 25.

This would simplify the transfer of the stack, in particular if the stack has become higher than normally necessary owing to the particular circumstances already mentioned above. The rest of the stack is then formed on the stack 28 by the subsequent stream of sheets.

However, the conveyor belt 22 of the carrying off section 20 continues running in the meantime, and conveys the stack 26 on to the carrying off stretch 27 now lying at the same height.

It should be noted that the individual conveyor belts are in part somewhat staggered in relation to each other, that is to say the depositing table 19 is somewhat lower than the preliminary collecting section 13 even in the upper position of the lowerable stacking table 17, and there may also be a small step between the carrying off section 20 and the carrying off stretch 27. This assists in providing a smooth flow of sheets, in particular for assisting in the transfer of the small stack 28 and preventing the following sheets 11 from striking its front edge.

Numerous variations of the embodiment iLlustrated and described are feasible. Although transportation by means of conveyor belts is particularly preferred, other transporting and conveying devices are however also feasible in particular for carrying off the stack. Pushers or stops driven by chains could be used.

Individual motors are shown in the drawings as drive mechanisms, but this is only for ease of illustration. All conveyors are normally driven by a con:mon synchronous shaft which also takes over the control of the stops and the lifting and lowering device.

WHAT WE CLAIM IS: 1. An apparatus for depositing sheets to a stack and for carrying off the stack, comprising a depositing table having a conveyor for carrying off a stack of sheets, means for raising and lowering the said table, a preliminary collecting section arranged upstream of the said table, and separating device selectively insertable into the path of the sheets travelling from the preliminary collecting section to the said table for temporary preliminary collection of sheets while a stack of sheets is carried off from the depositing table.

2. An apparatus according to claim 1, comprising a carrying off section which is situated downstream of the depositing table and which may be raised and lowered at least in part together with the depositing table, the carrying off section comprising a conveyor.

3. An apparatus according to claim 2, wherein the conveyor of the depositing table and the conveyor of the carrying off section are operable independently of each other.

4. An apparatus according to claim 2 or 3, wherein the depositing table and the carrying off section are raisable and lowerable together and parallel to each other.

5. An apparatus according to claim 2, 3 or 4, wherein at least one of the depositing table, the carrying off section and the preliminary collecting section has a conveyor belt.

6. An apparatus according to any one of claims 2 to 5, comprising a carrying off stretch situated opposite the said carrying off section when the latter is in its raised position.

7. An apparatus according to claim 6, wherein the said conveyors are adapted to convey the stack from the depositing table on to the carrying off section while the depositing table and carrying off section rises.

8. An apparatus according to claim 7, wherein the stack is adapted to be carried off from the carrying off section to the carrying off stretch in the upper raised positions of the depositing table and carrying off section.

9. An apparatus according to any preceding claim, comprising means for lowering the preliminary collecting section.

10. An apparatus according to any preceding claim, comprising at least one movable stop for forming the stack on the depositing table.

11. An apparatus for depositing sheets in a stack and for carrying off the stack, substan- tially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. is pivoted out and the conveyor belt of the preliminary collecting section 13 started up again. It should be noted that the small stack 28 is now transferred on to the depositing table and there pushed against the stop 25. A variation of this mode of operation is possible in which the conveyor belt 21 continues to be driven for a sufficiently long period for the stack 28 to strike the stop 25. This would simplify the transfer of the stack, in particular if the stack has become higher than normally necessary owing to the particular circumstances already mentioned above. The rest of the stack is then formed on the stack 28 by the subsequent stream of sheets. However, the conveyor belt 22 of the carrying off section 20 continues running in the meantime, and conveys the stack 26 on to the carrying off stretch 27 now lying at the same height. It should be noted that the individual conveyor belts are in part somewhat staggered in relation to each other, that is to say the depositing table 19 is somewhat lower than the preliminary collecting section 13 even in the upper position of the lowerable stacking table 17, and there may also be a small step between the carrying off section 20 and the carrying off stretch 27. This assists in providing a smooth flow of sheets, in particular for assisting in the transfer of the small stack 28 and preventing the following sheets 11 from striking its front edge. Numerous variations of the embodiment iLlustrated and described are feasible. Although transportation by means of conveyor belts is particularly preferred, other transporting and conveying devices are however also feasible in particular for carrying off the stack. Pushers or stops driven by chains could be used. Individual motors are shown in the drawings as drive mechanisms, but this is only for ease of illustration. All conveyors are normally driven by a con:mon synchronous shaft which also takes over the control of the stops and the lifting and lowering device. WHAT WE CLAIM IS:

1. An apparatus for depositing sheets to a stack and for carrying off the stack, comprising a depositing table having a conveyor for carrying off a stack of sheets, means for raising and lowering the said table, a preliminary collecting section arranged upstream of the said table, and separating device selectively insertable into the path of the sheets travelling from the preliminary collecting section to the said table for temporary preliminary collection of sheets while a stack of sheets is carried off from the depositing table.