WO2007147728A1

WO2007147728A1 - Device and method for placing flat workpieces on a stacking table

Info

Publication number: WO2007147728A1
Application number: PCT/EP2007/055529
Authority: WO
Inventors: Jörg Christian THIES; Thorsten KRÖGER
Original assignee: Windmöller & Hölscher Kg
Priority date: 2006-06-24
Filing date: 2007-06-05
Publication date: 2007-12-27
Also published as: DE502007002432D1; PT2035218E; ATE452749T1; DE102006029140B3; ES2337416T3; EP2035218A1; PL2035218T3; DK2035218T3; EP2035218B1

Abstract

The invention relates to a device (1) for vertically placing flat workpieces (3, 3') on a stacking table (4). In said device (1), the flat workpieces (3, 3') can be conveyed by a conveying cylinder (2) and can be dropped onto the stacking table (4). The leading ends of the flat workpieces (3, 3') are retained on the outer circumference of the conveying cylinder (2) with the aid of holding means and can be released before the workpieces (3, 3') reach the stacking table (4). Stripping means (5) are provided which encompass a plane (7), strip the workpieces (3, 3') released by the holding means from the outer circumference of the conveying cylinder (2), and deflect the workpieces (3, 3') along said plane in the direction of the stacking table (4). Additional holding fingers (10, 11) which allow the flat workpieces (3, 3') to be kept at a distance from the stacking table (4) can be introduced into the conveying path of the flat workpieces (3, 3'). Said holding fingers can be retracted behind the plane of the stripping means when the flat workpieces (3) are to reach the stacking table (4). The inventive stacking table (4) can be displaced relative to the conveying cylinder (2) along the plane (7) of the stripping means (5), in the direction of travel of the flat workpieces (3, 3').

Description

Apparatus and method for arranging flat workpieces on a collecting table

The invention relates to a device for the vertical arrangement of flat workpieces on a collecting table according to the preamble of claim 1 and a method according to the preamble of claim 10.

Such devices are used in particular for arranging bags provided with glued bottoms, in particular paper bags.

Such a device is already known from the patent EP 0 528 126 B1. In order to avoid repetition, the disclosure of said patent EP 0 528 126 B1 should be regarded as part of the disclosure of the present patent application.

Often, it is desirable to take a certain number of these workpieces again after the arrangement of these flat workpieces on the collecting table, for example, to package them in packets. Therefore, attempts have been made in the past to adapt such devices to this requirement. In order to facilitate the determination of this number, holding fingers may be provided in such devices, which are introduced slightly above the collecting table in the transport path of the workpieces and thus prevent the next workpiece from striking the collecting table. As long as these holding fingers limit the transport path, the following workpieces appear compared to the previously arranged workpieces whose transport was not limited by the holding fingers, offset by the elevated position. A certain number of these workpieces is thus placed in an elevated position. The workpieces maintain their elevated position, as the arranged workpieces are pressed with a spring force against the transport cylinder and thus there is a sufficiently high static friction between the workpieces, which prevents a mutual displacement of the same. Thus, for example, after every 50 workpieces a workpiece can be arranged in an elevated position, so that workpiece units can be removed in each case to an integer multiple of 50 of the device, without having to count the workpieces again. Because of this characteristic, such devices are often referred to as "counting stations." However, the actual counting of the workpieces is done by counting the revolutions of the transfer cylinder multiplied by the number of workpieces that have space on the outer circumference.

Such devices have basically proven in practice.

More particularly, however, bag making machines have recently been developed which allow the production of bags of various formats, which formats can be varied within a relatively wide range.

However, it now proves disadvantageous that, in particular, workpieces which have a large extent along the transport direction can often no longer be arranged without damage. When such workpieces are arranged on the collecting table, their upper ends are in a region in which a funnel-shaped region results between the perpendicular on the collecting table and the peripheral surface of the transporting cylinder, in which the workpieces are no longer sufficiently pressed against one another. The respectively last arranged workpiece is often loosely on the circumference of the transport cylinder. A subsequent, still guided by the transport cylinder workpiece now often takes part due to the prevailing friction, the previous workpiece. This leads to folds or compressions of the already arranged Workpiece, so that it is damaged and may subsequently be unusable.

The object of the present invention is to provide a device in which already arranged on the collecting table damage arranged flat workpieces are avoided.

The object is achieved by a device which comprises the features of the characterizing part of claim 1 in addition to the features of the preamble of claim 1.

The invention makes use of the fact that the collecting table, depending on the extent of the flat workpieces, is displaceable in a position in which the workpieces only with a small part of their area on the transport cylinder and with the majority of its surface on the plane abut the stripping agent. As a result, the respectively next workpiece is guided along a largely rectilinear transport path instead of a curved transport path on the preceding workpiece. The next workpiece thus comes in an area with the previous workpiece in contact, in the latter is completely in contact with the other already arranged workpieces. As a result, the tendency to compressions is greatly reduced, so that damage is largely prevented. Although the last transported by the transport cylinder workpiece, regardless of the position of the collecting table, always released at the same circumferential angle of the holding means of the transport cylinder, but the inertia of the workpiece is usually sufficient to impinge on the collecting table. Optionally, the further transport can still be supported by transport devices, as they are denoted by the reference numeral 41 in FIG. 3 of EP 0 528 126 B1.

In a particularly advantageous embodiment of the invention, it is provided that together with the collecting table and the holding fingers are displaceable relative to the transport cylinder. This measure prevents the workpieces that are to remain in a highlighted position from the risk of damage to which all workpieces are exposed in a device according to the prior art. According to this embodiment of the invention, therefore, the retaining fingers - as seen in the transport direction of the workpieces - always arranged at a constant distance to the collecting table.

It is advantageous if the holding fingers are articulated directly on the collecting table. The retaining fingers themselves are advantageously fastened to a shaft which extends parallel to the axis of rotation of the transport cylinder. In this case, the holding fingers are arranged so that they move in a direction during rotation of the shaft, which is initially substantially parallel to the plane of the collecting table. In this way, the workpieces, which are already arranged on the collecting table, acted upon only with a force acting perpendicular to the plane of extension of the workpieces force, so that further damage is avoided. The travel of the retaining fingers is relatively low, it only needs to be slightly larger than the thickness of the workpieces.

In an advantageous development of the drive for the shaft is mounted on the collecting table, so that the device is kept as simple and inexpensive.

Also for reasons of cost, the drive comprises a piston-cylinder unit which can be acted upon by a fluid, preferably compressed air.

As already described in EP 0 528 126 B1, a generic device according to the prior art is equipped with a stripping means designated there as stripper, with which the workpiece is stripped from the outer peripheral surface of the transport cylinder, if this from the holding means, such as Falzzangenbacken, is given freely. According to an advantageous embodiment of the invention, these stripping means are designed as a plate or as a sheet, the workpieces facing surface plane is advantageously parallel to the tangential plane, which rests against the point at the transport cylinder on which the workpieces of be released to the holding means. The plane of the sheet or the plate and the tangential plane can also be identical.

The plate or plate has grooves, oblong holes or elongated recesses which run parallel to the transport direction of the workpieces along the plate. In these grooves, oblong holes or elongated depressions, the

Retaining fingers are withdrawn when the workpieces are to reach the collecting table. In a displacement of the collecting table together with the retaining fingers the latter within the grooves, slots or elongated depressions are displaced. This leads to a mechanically simple construction of the entire device and to accelerate the adjustability of the device to a new format of the workpieces.

The invention also includes a method for vertically positioning flat workpieces on a collecting table, in which the flat workpieces are transported by a transporting cylinder and dropped onto the collecting table, the flat workpieces being held and supported at their leading ends by holding means on the outer circumference of the transporting cylinder be released to reach the collecting table, in which the released workpieces are stripped by Abstreifmittel from the outer periphery of the transport cylinder and directed along its plane in the direction of the collecting table, in which after a certain number of collected workpieces additional holding fingers are introduced into the transport path of the flat workpieces, with which the following flat workpieces are kept at a distance from the collecting table, and in which the holding fingers are retracted back behind the plane of the stripping means when the flat workpieces are again up to the collecting table to reach, wherein the number of workpieces that reach the collecting table and the number of workpieces that are kept at a distance from the collecting table, can be entered into a computing and control device, and wherein the computing and control device issues control commands when the retaining fingers are to be introduced into the transport path of the workpieces or withdrawn again.

A computing and control device is thus also part of the device according to the invention. With the method according to the invention and the device according to the invention, it is thus possible to arrange any number of workpieces in a different position from any other number of workpieces. The arrangement of the workpieces on the collecting table can thus be adapted more flexibly to the needs.

An embodiment of the invention will become apparent from the description and the claims.

The only figure shows:

Fig. 1 side view of a device according to the invention

Fig. 1 shows a device 1 for arranging flat workpieces on a collecting table 4B. The flat workpieces 3, for example, provided with a folded bottom paper bag, are moved by the transport cylinder 2, which rotates in the direction of arrow A, in the direction of the collecting table 4. The workpieces 3 are held by not shown, but in EP 0 528 126 B1 further explained Falzzangen on the outer circumference of the transport cylinder 2, wherein the Falzzangen grasp the workpiece 3 at its leading end. Tangentially to the transport cylinder 2 is designed as a baffle 5 trained Abstreifmittel. Just before the workpiece 3 reaches the upper tip 6 of the baffle 5, the Falzzangen release the workpiece 3, so that it is no longer taken along by the transport cylinder 2, but moves along the outer surface 7 of the baffle 5 along. This outer surface 7 is formed as a plane. The workpieces 3 now slide along the baffle 5 until they impinge on the collecting table 4 with their lower edges. Optionally, the movement of the workpiece 3 along the baffle 5, for example, with the in Fig. 3 of EP O 528 126 B1 shown, but not shown here conveyor belts are supported. The support plane 8 of the collecting table 4 and the outer surface 7 of the guide plate 5 are arranged substantially perpendicular to each other, so that the workpieces 3 are arranged perpendicular to the support plane 8 of the collecting table 4. The collecting table 4 is displaceable in the direction of the double arrow B and thus adapted to the length of the workpieces that they are no longer or only a small part in contact with the transport cylinder 2 after their arrangement.

By the holder 9, which acts in a direction not shown on the guide plate 5 with a force and which is movable along the support plane 8 of the collecting table, the workpieces 3 are pressed against the baffle 5, wherein the force is so low that a arriving workpiece 3 between baffle 5 and already arranged workpieces 3 can pass without workpieces 3 are damaged.

In order to allow some workpieces 3 'to survive with their upper edge over the upper edges of other workpieces 3, retaining fingers 10 are provided, which can be brought out of the outer surface 7 of the baffle, but are also retractable behind the outer surface 7 of the baffle. This movement is indicated by the double arrow C. The retaining fingers, of which only the foremost one is visible in the side view shown, can be moved back and forth between two end positions. When the retaining finger 10 protrudes from the outer surface 7 of the baffle 5, a retaining lug 11 limits the transport distance of each incoming workpiece 3 ', so that this in a relative to the workpieces 3, which have reached the support level 8 of the collection table 4, elevated position for Standstill comes. Due to the pressure exerted by the holder 9, the workpiece 3 'does not slip even when it is no longer held by the retaining lugs 11.

In order to move the retaining fingers 10, a compressed air cylinder 12 is provided, which is pivotally connected to a support arm 13, the latter being fixed to the collecting table 4. The piston 14, which is movable by the compressed air cylinder 12 in the direction of the double arrow D, is articulated connected to a lever 15. The lever 15 sets a shaft 16 in rotation, which is rotatably mounted end in support arms 17. A plurality of levers 18 carrying the holding fingers 10 are fastened to the shaft, so that the rotational movement of the shaft 16 essentially results in a displacement movement of the holding fingers 10 in the direction of the double arrow C. The compressed air supply to the compressed air cylinder 12 and thus the movement of the cylinder 12 are controlled by a computing and control device, not shown. This computing and control device counts the workpieces 3, 3 'transported by the transport cylinder 2 and, following a preselectable number of workpieces 3 by the operator, activates the compressed air supply so that all subsequent workpieces 3' are arranged in the raised position mentioned. Only when a likewise preselectable number of workpieces 3 'has been arranged in the raised position, the compressed air supply to the compressed air cylinder is deflected, so that the piston retracts, with the result that the retaining fingers are withdrawn behind the outer surface 7 of the baffle 5 again ,

The workpiece 3, 3 'facing surface of the retaining finger 10 may be inclined to the outer surface 7. Such an inclination produces a braking effect on the workpiece 3, 3 ', so that this does not impinge on the retaining lug 1 1 at full speed, whereby the workpieces 3, 3' could otherwise be damaged.

The movement of the holding finger 10 in the direction of the arrow C can be limited, for example, by stops, not shown. The limitation can be designed to be adjustable, so that the movement distance of the holding finger or the variable is variable. Due to the variable position of the retaining fingers (10) to the outer surface (7) a higher or lower braking effect is achieved. The workpieces 3, 3 'are thereby delayed more or less. With the mentioned adjustability can therefore be taken into account on the material of the workpieces and / or on their weight. In this way, damage to the workpiece 3, 3 'can be avoided for every weight and every material, but at the same time it can also be ensured that the workpiece 3, 3' also reaches the retaining lug 11.

Claims

Apparatus and method for arranging flat workpieces on a collection table Patent claims

Device (1) for vertical arrangement of flat workpieces (3, 3 ') on a collecting table (4),

- In which the flat workpieces (3, 3 ') of a transport cylinder (2) and transportable to the collecting table (4) are ejected, the flat workpieces (3, 3') at their leading ends of holding means on the outer circumference of Transport cylinder (2) durable and before reaching the collecting table (4) are releasable,

- In the Abstreifmittel (5) are provided with a plane (7) which strip the already released by the holding means workpieces (3, 3 ') from the outer periphery of the transport cylinder (2) and along said plane (5) in the direction of the collecting table (4) direct,

- in which additional retaining fingers (10, 11) can be introduced into the transport path of the flat workpieces (3, 3 '), with which the flat workpieces (3') at a distance from the collecting table (4) are durable, wherein the retaining fingers (10, 11) behind the plane of the Abstreifmittel (5) are retractable when the flat workpieces (3) to reach the collecting table (4), characterized in that the collecting table (4) relative to the transport cylinder (2) along the plane (7 ) of the stripping means (5) in the transport direction of the flat workpieces (3, 3 ') is displaceable.

2. Device (1) according to claim 1, characterized in that the holding fingers (10) together with the collecting table (4) relative to the transport cylinder (2) are displaceable.

3. Device (1) according to one of the preceding claims, characterized in that the holding fingers (10) are hinged to the collecting table (4).

4. Device (1) according to the preceding claim, characterized in that the holding fingers (10) are mounted on a parallel to the axis of rotation of the transport cylinder (2) extending shaft (16).

5. Device (1) according to any one of the preceding claims, characterized in that the holding fingers (10) of a mounted on the collecting table (4) drive (12) are drivable.

6. Device (1) according to the above drive, characterized in that the drive is a piston-cylinder unit (12).

7. Device (1) according to any one of the preceding claims, characterized in that the stripping means (5) comprise a plate or plate, in the plane (7) in a direction perpendicular to the collecting table (4) extending slots or grooves are introduced.

8. Device (1) according to the preceding claim, characterized in that the retaining fingers (10) are retractable into the slots or grooves.

9. Device (1) according to one of the two preceding claims, characterized in that the retaining fingers (10) move along the grooves or slots when the collecting table (4) is moved.

10. Method for vertically arranging flat workpieces (3, 3 ') on a collecting table (4),

- In which the flat workpieces (3, 3 ') of a transport cylinder (2) transported and dropped onto the collecting table (4), wherein the flat workpieces held at their leading ends of holding means on the outer circumference of the transport cylinder (2) and be released before reaching the collecting table (4),

- In which the released workpieces (3, 3 ') by stripping means (5) from the outer periphery of the transport cylinder (2) stripped and directed along its plane in the direction of the collecting table (4),

- In which after a certain number of collected workpieces (2) additional holding fingers (10) in the transport of the flat workpieces (3, 3 ') are introduced, with which the following flat workpieces (3, 3') at a distance from the collecting table (4 ) being held,

- And in which the retaining fingers (10) are retracted again behind the plane of the Abstreifmittel (5), when the flat workpieces (3, 3 ') to get back to the collecting table (4), characterized

- That the number of workpieces (3, 3 '), which reach the collecting table (4) and the number of workpieces (3, 3'), which are kept at a distance from the collecting table (4), in a computing and control device are entered, and

- That the arithmetic and control device issues control commands when the retaining fingers (10) in the transport path of the workpieces (3, 3 ') introduced or ought to be withdrawn.