EP0792813A1 - Machine for unpacking rolls, especially printing paper rolls - Google Patents

Abstract

A knife (38) is arranged on a knife carriage (30) which is movable over the length of a roller (R) and can be inserted under a casing (D) in order to cut it open from the inside. A further knife (48) is arranged behind the knife (38) on the knife carriage (30), with which one or more turns of the roll (R) adjoining this can be cut open during the cutting of the sheath (D). <IMAGE>

Description

The invention relates to an unpacking machine for rolls, in particular printing paper rolls, which have a cover free of frontal covers, in particular packaging paper, according to the preamble of claim 1.

Newsprint and other paper intended for printing on rotary machines is usually supplied in the form of packaged rolls. The packaging that has to be removed in the print shop usually consists of circular covers on both ends of each roll and a multi-layer wrapping of wrapping paper wrapped around the roll. When unpacking, the front covers are removed first; this is done by hand or with known devices and is not the subject of this invention. Unpacking machines of the type mentioned are intended to undress rolls, which have already been freed from their front covers or have been supplied without such covers, from their essentially cylindrical cover.

Such unpacking machines usually have a machine frame on which a radial slide can be adjusted according to the diameter of a roll to be unpacked. The roller is centered with respect to the machine frame, for example in that its outer surface has been placed on a pair of axially parallel rollers. The unpacking machine also includes a knife carriage that runs along a longitudinal guide Surface line of the roll is movable over its length. The longitudinal guide is supported on the radial slide, so it takes part in its radial adjustment movements. A knife is arranged on the knife carriage and can be inserted into the casing from one end face in order to cut it open from the inside.

A state-of-the-art unpacking machine of the type mentioned is known from EP 0 634 329 A1. There is a gripper with two jaws arranged on the radial slide, which can be pressed essentially radially against the wrapping paper made of a roll to be unpacked and can then be moved in opposite directions essentially tangentially to one another in order to form a tunnel-like bulge in the wrapper. The knife is wedge-shaped or crescent-shaped and penetrates into the bulge when the knife carriage moves longitudinally in order to cut it open from the inside. In general, this also affects the top layer of usable, so-called "white" paper, which when the two gripper jaws move tangentially from the bottom layer of packing paper is dragged along and therefore forms part of the bulge.

Experience has shown that, once the cover and the top layer of white paper have been removed, one or more additional layers of white paper have to be removed, since it can now be seen that they are damaged. It is even more important to remove several layers of white paper that are not suitable for printing from rolls that have been delivered without wrapping from wrapping paper or the like. However, such paper is usually wrapped too smoothly and / or too tightly for a bulge to be formed in the manner described by means of a gripper, which can then be wrapped with e.g. wedge-shaped or sickle-shaped knives could be cut open from the inside out. The removal of damaged white paper has therefore previously required a separate operation, generally on a separate machine.

The invention has for its object to simplify the removal of defective white paper.

The object is achieved according to the invention starting from an unpacking machine of the type mentioned with the features of claim 1.

In the tandem arrangement of two knives according to the invention, the first one can be designed in a known, for example wedge-shaped or crescent-shaped, design for penetrating into a bulge of a wrapping paper previously formed by gripper jaws. The second knife, which is arranged behind the first knife on the knife carriage, is intended to cut open one or more further turns of the roll, in particular consisting of white paper. The tandem arrangement of two knives according to the invention thus makes it possible to carry out two previously separate work steps during a single work cycle of the knife carriage. Normally both knives work in direct succession in the same working stroke; but it is also possible to control the second knife so that it remains idle during a forward stroke of the knife carriage and does its work only during the return stroke.

Advantageous developments of the invention result from claims 2 to 8.

From WO 94/11 254 A1, an unpacking machine is known which, for cutting open a cylindrical casing, has a knife which can be moved along a surface line of the casing, which is arranged in the middle behind a pair of inclined castors and by a curved blade which is sharp on the top or by a circular knife and can be arranged between two skids lifting the sheath. The inclined rollers push the casing together in the area of the surface line along which it is to be cut open, in such a way that the casing forms a bulge which is underpinned by the curved blade or by the runners. In order that the casing can be cut open during a forward or a backward movement, an embodiment of this unpacking machine has two pairs of rollers inclined in opposite directions and two circular knives, of which only one circular knife is effective in each direction of movement. The item to be unpacked lies directly under the casing, for example a stack of can lids; it is not intended to cut open anything below the casing.

Fig. 1

eine Vorderansicht einer erfindungsgemäßen Auspackmaschine,

Fig. 2

die zugehörige Draufsicht,

Fig. 3

die Vorderansicht in Richtung des Pfeils III in Fig.2,

Fig. 4

Einzelheiten aus Fig.3 in größerem Maßstab,

Fig. 5

die Ansicht in Richtung des Pfeils V in Fig. 3,

Fig. 5a

die gleiche Ansicht, jedoch in anderer Betriebsstellung,

Fig. 6

die Teilansicht in Richtung des Pfeils VI in Fig.2,

Fig. 7

den Schnitt VII-VII in Fig.6,

Fig. 8

eine vergrößerte Teilansicht in Richtung des Pfeils VIII in Fig.7,

Fig. 9

die Ansicht in Richtung des Peils IX in Fig.8 und

Fig.10

eine stark vergrößerte Teilansicht in Richtung des Pfeils X in Fig.9.

An embodiment of the invention is explained below with the aid of schematic drawings with further details. Show it:

Fig. 1

2 shows a front view of an unpacking machine according to the invention,

Fig. 2

the associated top view,

Fig. 3

the front view in the direction of arrow III in Figure 2,

Fig. 4

Details from Figure 3 on a larger scale,

Fig. 5

the view in the direction of arrow V in Fig. 3,

Fig. 5a

the same view, but in a different operating position,

Fig. 6

the partial view in the direction of arrow VI in Figure 2,

Fig. 7

the section VII-VII in Figure 6,

Fig. 8

3 shows an enlarged partial view in the direction of arrow VIII in FIG. 7,

Fig. 9

the view in the direction of Peils IX in Fig.8 and

Fig. 10

a greatly enlarged partial view in the direction of arrow X in Fig.9.

The unpacking machine shown has a centering device 1, which is intended to arrange a roll R of packaged printing paper with a horizontal axis A in a vertical reference plane B, normal to a longitudinal center plane C of the unpacking machine. The roll R has a sleeve D, which consists for example of wrapping paper, and is to be removed. The centering device 1 is arranged below a portal-like front or starting area of a machine frame 2, which carries all the devices required for removing the casing D, namely a gripping device 3 for forming a bulge E in the casing D, a cutting device 4 for cutting open the casing D along one Surface line, so in a direction substantially parallel to the axis A, a peeling device 5 for peeling the cut cover D from the roll R, a winding device 6 for space-saving winding of the peeled cover D, a pivoting device 7 for pivoting the wound cover D into a position normal to the axis A. , a squeezing device 8 for squeezing the wrapped sleeve D and finally a sorting device 9 for separately disposing of the sleeve D on the one hand and adjoining printing paper, so-called white paper, on the other hand. In most cases, one or more layers of white paper must also be removed after the cover D before the roll R can be handed over to a rotary printing press or the like ready for use.

The centering device 1 includes a pair of support rollers 10, which are mounted parallel to each other on both sides of a conveyor 11 in a common horizontal plane. At least one of the two support rollers 10 can be driven in rotation. On the conveyor 11, which is, for example, a roller conveyor, a roller R can be conveyed in the direction of its axis A, while the support rollers 10 assume a lowered position indicated by dash-dotted lines in FIG. The two support rollers 10 can be raised together with the roller R into their operating position drawn with full lines in FIG. 1; the roller R is then rotatable about its axis A, which lies reliably in the reference plane B; this is the vertical center plane between the two support rollers 10.

The machine frame 2 has, above the centering device 1, a horizontal support 12 which is parallel to the reference plane B and has an upwardly projecting support 13 attached to each of its two ends. On the two supports 13, a radial slide 14 is guided up and down in the reference plane B, that is to say radially to the roller R; for its radial movements, two mutually synchronized motors 15, for example electric motors, are arranged on each of the two supports 13. The radial slide 14 is frame-like and has an in the horizontal plane 16 lying on the reference plane B, on which a pliers slide 17 is guided horizontally and can be adjusted parallel to the axis A by means of a motor 18, for example a piston-cylinder unit.

The pliers slide 17 is part of the gripping device 3; on it a pair of two-armed levers 19 are mounted, which together form a gripper 20 and each have a jaw 21 at their lower ends made of a material with a high coefficient of friction, for example made of polyurethane. The upper ends of the two levers 19 are connected by a toggle lever arrangement 22 to a motor 23, which can be a pneumatic piston-cylinder unit, for example.

The cutting device 4 includes a longitudinal guide 24, which is also located in the reference plane B and normally extends essentially parallel to the axis A of the roller R. The longitudinal guide 24 is arranged essentially below the radial slide 14 and is pivotally mounted on the radial slide 14 at one of its ends, the left one in FIG. 4, by means of a pivot bearing 25 in the reference plane B. At the opposite end, on the right in FIG. 4, the longitudinal guide 24 is connected to the radial slide 14 by a servomotor 26, preferably a digitally controllable electric motor. The servomotor 26 is controlled by a sensor 27 which can be moved back and forth on the radial slide 14 by means of a motor 28 normally to the reference plane B and vertically by means of a motor 29.

On the longitudinal guide 24, a knife carriage 30 can be moved back and forth by means of a motor 31 between an initial position drawn with full lines in FIG. 4 and an end position indicated with dashed lines. The path which the knife carriage 30 travels between these two positions, as shown in FIG. 4, is somewhat larger than the length of the longest occurring roll R. The knife carriage 30 has a first vertical guide 32 on which a first knife carrier 33 guided and is usually held by a locking device 34 in a central position with low holding force. The latching device 34 is formed, for example, by a spring-loaded ball guided in the knife carriage 30 and a pan incorporated into the vertical guide 32, into which the ball can latch. 6 and 7, a cam follower 35 is arranged on one side of the knife carriage 30, for example a roller which can be rotated about an axis normal to the reference plane B. A return guide 36 is assigned to the cam follower 35, which is fastened in the start region of the longitudinal guide 24 on the right in FIG. 4 and left in FIG. 6 and centers the cam follower 35 each time the knife carriage 30 returns to its initial position. In this way, it is ensured that the first knife carrier 33 always comes into its latching position before the knife carriage 30 begins a work path, from right to left in FIG.

A first knife 38 is mounted on the first knife carrier 33 by means of a joint 37, the axis of which extends normal to the reference plane B, the inclination of which can be adjusted with respect to the first knife carrier 33 by means of a pair of adjusting screws 39. The first knife 38 is substantially wedge-shaped, equipped with a slightly concave cutting edge 40 and carries a thin, flat guide blade 41 made of highly elastic material, for example hardened spring steel, which extends beyond the front end of the cutting edge 40 to such an extent that it is able to the forward movement of the knife carriage 30 to slide like a skid on the roller R and thereby determine the height of the first knife carrier 33 with respect to its guide 32. The mobility of the first knife carrier 33 with respect to the first vertical guide 32 downwards is limited by a stop 42.

Behind the first vertical guide 32, to the right in FIGS. 4, 8 and 9, a second vertical guide 43 is arranged on the knife carriage 30, on which a motor 44, for example a pneumatic piston-cylinder unit, adjustable second knife carrier 45 is guided vertically. On an axis 46, which extends normal to the reference plane B and is rotatably mounted on the second knife carrier 45, a second knife 48 designed as a circular knife and two impellers 49 are releasably clamped between two flanges 47. The two impellers 49 define an outer cylindrical surface over which the second knife 48 with its circular cutting edge protrudes slightly, for example by 0.1 mm. If the contact pressure is sufficiently strong, the second knife 48 can already be effective when its radius roughly corresponds to that of the two impellers 49, ie the circular cutting edge does not protrude appreciably beyond the cylindrical lateral surfaces of the impellers 49. The radial protrusion of the circular cutting edge over the lateral surfaces mentioned should generally not be more than 0.2 mm.

As far as the unpacking machine has been described so far, it works as follows:

The arrival of a roll R on the conveyor 11 is monitored as usual by sensors, not shown. The conveyor 11 is stopped as soon as the roller R has reached a position symmetrical with respect to the longitudinal center plane C, as indicated by dash-dotted lines in FIGS. 2 and 3, the two most distant vertical dash-dotted lines in FIG a roll R with the greatest possible length, and the two other vertical dash-dotted lines correspond to the two ends of a roll with the shortest possible length. 1 and 3 also show the extent to which the diameter of the rolls R which can be unpacked on the machine according to the invention can vary.

As soon as a roller R has reached its symmetrical position with respect to the longitudinal center plane C and while the roller R is also centered with respect to the reference plane B by lifting the support rollers 10, a further sensor, not shown, is provided Conventional design for the tong carriage 17 to be moved by its motor 18 into a position which is adapted to the length of the roll R to be unpacked. The jaws 21 of the gripper 20 are in an area adjacent to the plane of the front end face of the roller R on the right in FIGS. 3 and 4. From Figure 3 it can be seen that the jaws 21 have a length measured in the direction of the axis A, which is small in relation to the length of the roll R, even the shortest roll occurring. For example, the length of the jaws 21 is on the order of between about a fifth and about a tenth of the roll length.

As soon as the jaws 21 are arranged over the front area of the casing D, the two motors 15 of the radial slide 14 are switched on and lower it. The gripper 20 takes part in the downward movement of the radial slide 14 in the open state according to FIG. As soon as the two jaws 21 rest with a predetermined pressure on the front end region of the casing D and thereby generate a specific reaction torque on the motors 15, these are switched off. The motor 23 is then extended in accordance with FIG. 5 a, so that the gripper 20 closes. Its two jaws 21 create a tunnel-like bulge E in the shell D, since the jaws 21 push the generally multi-layer shell D together in the direction of the reference plane B. In general, this also affects the outermost layer of white paper on roll R, since it is taken away by friction from the wrapping paper lying on it and forming envelope D.

Measured in a direction parallel to the axis A, ie along a surface line, the tunnel-like bulge E is only as long as or only less than the jaws 21; the tunnel-like bulge E thus does not extend by far over the entire length of the roll R. Therefore, the forces initially exerted by the jaws 21 essentially radially and then essentially tangentially on the sleeve D concentrate on the area which corresponds to the 3 and 4 right end face of the roller adjacent. Is in this area the tunnel-like bulge E is so pronounced in any case that it is easily and safely accessible for the guide blade 41.

However, before the guide blade 41 can be inserted into the bulge E, its position, which is dependent on the diameter of the roller R, is located by the sensor 27. For this purpose, the sensor 27 is brought by the motor 28 from its rest position laterally offset from the reference plane B into the reference plane and then slowly moved upwards by the motor 29 from a lower end position. This upward movement is followed by the longitudinal guide 24, since its servomotor 26 is switched so that it is dependent on the motor 29 of the sensor 27, expediently with a certain caster. As soon as the sensor 27, preferably working with a laser beam, has located the bulge E at the right end of the roller R in FIG. 4, it is certain that the first knife 38 assumes the height position in which its guide blade 41 can penetrate the bulge E.

Now the motor 31 is switched on so that it moves the knife carriage 30 from its initial position into its end position, from right to left in FIG. The guide blade 41 penetrates into the bulge E and guides the first knife 38 within the bulge E over any irregularities in the roll R. As a result, the sleeve D and the outermost layer of white paper, which together with it forms the bulge E, are reliably cut from the inside to the outside over the entire length of the sleeve D. Immediately behind it, the layer of white paper left at the top under the bulge E is cut radially by the second knife 48 from the outside inwards. This is generally necessary to ensure that the top layer of white paper, which has mostly become unusable due to gluing, is removed together with the sleeve D.

The effect of the second knife 48 depends on whether, and if so to what extent, the motor 44 has a downward pressure on the second, that is to say radially inward, relative to the roller R. Knife carrier 45 exercises. The motor 44 is controlled so that it only exerts this pressure when the second knife 48 has reached the plane of the front end face of the roller R. The penetration depth of the second knife 48 is of course also dependent on the extent to which its circular cutting edge projects beyond the cylindrical outer surface of the two impellers 49.

If, after removal of the casing D and one or more layers of white paper originally cut open at the same time, it becomes apparent that further layers of the white paper are unusable, the knife carriage 30 can be brought back into its starting position and moved again over the roller R, whereby the first knife 38 no longer causes anything and only the second knife 48 cuts through other layers of paper, the number of which depends on the pressure that the pneumatic motor 44 exerts on the second knife carrier 45.

Claims (8)

Unwrapping machine for rolls, in particular printing paper rolls, which have a cover free of frontal covers, in particular of packing paper, with - A knife carriage (30) which is movable over the length of a roller (R), and a knife (38) which is arranged on the knife carriage (30) and can be inserted under the casing (D) in order to cut it open from the inside,
characterized in that a further knife (48) is arranged on the knife carriage (30) behind the knife (38), with which one or more turns of the roll (R) adjoining this can be cut open during the cutting of the casing (D). Unpacking machine according to claim 1,
characterized in that the further knife (48) is guided on the knife carriage (30) so as to be adjustable approximately radially to the roller (R). Unpacking machine according to claim 2,
characterized in that the further knife (48) can be loaded with an approximately radial force with respect to the roller (R), which is adjustable and constant during a movement along the roller (R). Unpacking machine according to one of claims 1 to 3,
characterized in that the further knife is a circular knife (48). Unpacking machine according to claim 4,
characterized in that the circular knife (48) is assigned at least one impeller (49) which delimits its penetration depth and can be rolled on the roller (R). Unpacking machine according to claim 5,
characterized in that the circular knife (48) is arranged between two impellers (49). Unpacking machine according to claim 6,
characterized in that the circular knife (48) and the two impellers (49) are arranged coaxially. Unpacking machine according to claim 6 or 7,
characterized in that the circular knife (48) does not protrude by more than 0.2 mm over a common tagential plane of the two impellers (49).

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