EP0507910A1 - Device for cutting through a strip of material. - Google Patents

Abstract

In coiling machines for strips of material (4), in particular strips of paper or cardboard, devices are known for cutting the strips of material (4) on the carrier or support cylinder (1), which have an element for separation movable transversely with respect to the direction of unwinding of the strip and which can be placed on the strip (4) in the area where the latter surrounds the carrier or support cylinder (1). In order to allow a reliable sectioning of the strip (4) when changing the coils, while having a simple construction, a separating element is used, according to the invention, a wheel (19) rotating freely and having on its circumference a sharp edge which can be applied elastically against the carrier or support cylinder (1).

Description

 DESCRIPTION

Device for severing a web of material

Technical field

The invention relates to a device for severing a material web, in particular a paper or cardboard web, on the support or support roller of a winding machine according to the preamble of patent claim 1.

In the case of rewinders for paper or cardboard webs, when changing rolls, it is necessary to reliably separate the individual webs produced by slitting. In order to change the reels as quickly as possible, the web is expediently cut on the support or support roller at the point at which the new web beginnings created during the separation have the position required for winding onto new winding tubes.

State of the art

From DE-OS 29 20 707 a carrier roll winding machine is known, in which the cutting of the web is carried out by means of a separating device moving up through the carrier roll nip, at the tear-off blade of which the web breaks when the full winding rolls are ejected. The newly created beginnings of the web are held by means of negative pressure on the support roller designed as a suction roller until new winding sleeves are inserted. It is not necessary to reposition the start of the web for winding. This advantageous separating device cannot be used in support roller winding machines in which the winding rollers lie on a support roller on both sides of the apex line when winding along two winding lines, since the full winding rollers of the two winding lines are removed from the machine in opposite directions - in and against the web running direction . To cut the web in backing roll winding machines, a generic device is therefore proposed in DE-OS 36 11 895, in which a scraper in the looped area of the backing roll can be placed on the web and moved transversely to the web running direction. The cutting edge of the separating scraper is designed as a saw and cuts through the web when moving transversely to the web running direction.

It has been shown in practice that separating scrapers designed as saws have to be designed in a very complex manner since they require great forces to cut the web.

Presentation of the invention

The invention has for its object to improve a generic device so that it is structurally simple to safely cut the web when changing roles.

This object is achieved with the characterizing features of patent claim 1.

According to the invention, a rotatable, circumferentially sharp wheel is used as a separating device, with which the web can be severed or at least weakened to such an extent that it tears through the increased web tension when the winding rollers are raised or lowered for unloading. The resilient support limits the maximum contact pressure so that damage to the roller surface is avoided.

The subclaims contain preferred, since particularly advantageous, embodiments of the invention. While a wheel made of hard metal or hardened tool steel according to claim 2 ensures long service lives, the bearing of the wheel on an inclined pin according to claim 3 has proven to be particularly advantageous, since good separation results are achieved with the least possible effort.

The embodiment according to claim 4 contains a structurally particularly advantageous drive of the wheel for the transverse movement.

Claims 5 and 6 claim winding machines using the separating device according to the invention, wherein the inflatable clamping hose according to claim 6 prevents a disruptive propagation of the increased web tension when the web is severed by increasing the web tension.

Brief description of the drawing

The drawing serves to explain the invention with reference to an embodiment shown in simplified form.

Fig. 1 shows a partial side view

Back-up roll winding machine in which the separating device is integrated in the lowering platform

Fig. 2 shows an enlarged section of Fig. 1 and

FIG. 3 shows a plan view in the direction of arrow "Y" in FIG. 2.

Way of carrying out the invention

The section shown in Fig. 1 in side view winding machine has a support roller 1 designed as a suction roller, on which the winding rollers 2, 3 during winding up on the web 4 - a paper or cardboard web - rest. The winding rolls 2, 3 are each held by guide heads 5, 6 which can be inserted laterally into the winding sleeves. Before winding, the web 4 is divided into several individual webs by slitting, alternately the one on either side of the apex line of the support roller 1 Arranged arranged winding lines and wound up there to winding rolls 2, 3 aligned. Two lowering platforms 7, 8 are used to remove the winding rolls 2, 3 from the machine, each of which can be raised to the underside of the winding rolls 2, 3 by means of piston-cylinder units 9. After the guide heads 5, 6 have been extended from the winding rollers 2, 3, the lowering platforms 7, 8 are lowered, and the winding rollers 2, 3 are transported away. The lowering platform 7 on the inlet side is only shown in part in FIG. 1.

A cutting device 10 integrated into the lowering platform 8 on the outlet side, which is shown enlarged in FIGS. 2 and 3, serves to cut the web 4. On the side of the lowering platform 8 facing the support roller 1, a piston rodless, pneumatic piston-cylinder unit 11 extending over the entire working width is fastened. On the piston bracket 12 of the piston-cylinder unit 1 1, a plate 13 is screwed, on the side facing the support roller 1, a short lever 14 is articulated. For this purpose, the lever 14 has a bearing eye 15 which can be clamped to the plate 13 by means of a screw 16 in order to fix the angle of attack to the support roller 1. The free end of the lever 14 is fitted into a helical spring 17 and firmly wedged with it. In the other end of the coil spring 17, a pin 18 is wedged, which is extended at the end in the shape of a fork. In the fork-shaped extension, a wheel 19 made of hard metal or hardened tool steel with a circumferential sharp cutting edge is freely rotatably mounted in the manner of a glass cutter. The wheel 19 has a diameter of approximately 5 mm. So that it rolls across the web 4 supported by the support roller 1 when moving transversely to the web running direction, its axis of rotation is perpendicular to the support roller axis. When pivoting the lowering platform 8 in the direction of the support roller 1, the wheel 19 is pressed against the web 4 resting on the support roller 1. Due to the inclined position of the lever 14, the part of the spring 17 holding the pin 18 bends when placed on the track 4, so that the wheel 19 is pressed against the track 4 by the spring 17. The lowering platform 8 is pivoted so far that an angle between the axis of the pin 18 and the surface line of the support roller 1 is set in the working position, which is between 15 ° and 35 °. The pin 18 is thereby inclined against the direction of movement (arrow 20), so that the wheel 19 is pulled over the web 4 during movement.

Below the piston-cylinder unit 11, a support plate 21 is attached to the lowering platform 8, on the side facing the support roller 1, an inflatable clamping hose 22 corresponding to the working width is clamped. In the pivoted position of the lowering platform, the clamping hose 22 expands when inflated between the support roller 1 and the support plate 21 and thus clamps the web 4 on the support roller 1.

After the winding rolls 2, 3 are completely wound, the support roller 1 is stopped and the web 4 is held on the support roller 1 by means of suction air. The lowering platforms 7, 8 are raised - shown in broken lines in FIG. 1 - the separating device 10 integrated in the lowering platform 8 is thus brought into the working position shown in FIGS. 2 and 3. The wheel 19 is pressed by the spring 17 against the web 4 resting on the support roller 1. The clamping hose 22 is inflated to hold the web 4 in addition to the suction air during the separation process. Then the piston-cylinder unit 11 moves the pressed wheel 19 across the entire width of the web. The ^'web 4 is or weakened, depending on their thickness either completely severed. As a rule, only a weakening of the web 4 takes place, the complete severance then takes place by increasing the web tension when the winding rolls 2, 3 are unloaded. With the winding stations on the inlet side, the web tension increases when the winding rolls 2 are lowered with the lowering platform 7, thereby tearing single webs wound through these stations.

So that the web tension increases at the winding stations on the outlet side, the lowering platform 8 is positioned at a short distance below the winding rollers 3 for unloading. After loosening the guide heads 6, the winding rollers 3 roll a short distance over the lowering platform 8 and rotate in the direction of arrow 23 (FIG. 1). The increase in web tension resulting from the rotation cuts through the individual webs wound on the exit side. The inflated clamping hose 22 prevents the web tension increase from propagating into the longitudinal cutting device arranged below the support roller 1 _.

and causing problems there. The increase in web tension of the single webs wound on one side when lowering the lowering platform 7 poses no problems, since these single webs loop around the support roller 1 at a large angle, so that the web train increase cannot propagate. When lowering the lowering platform 8, the piston-cylinder unit 11 is moved back with the wheel 19 into the starting position for the next separation process. After inserting new winding cores, the newly created web starts are wound onto them. While the beginning of the web to be wound on the exit side can be wound directly onto the inserted winding tubes, the beginning of the web to be wound on the one side is first transported to the corresponding winding stations by means of the support roller 1.

Claims

PATENT CLAIMS 1. Device for severing a material web (4), in particular one Paper or cardboard web, on the support or support roller (1) one Winding machine, with one in the wrapped area of the support or support roller (1) on the web (4) attachable and movable transversely to the web running separating element, characterized by a freely rotatable, circumferentially having a sharp edge and resilient against the support or Back-up roller (1) pressable wheel (19) as a separating element. Second Device according to claim 1, characterized gekennzeich¬ net that the wheel (19) is made of hard metal or hardened tool steel. 3rd Apparatus according to claim 1 or 2, characterized gekenn¬ characterized in that the wheel (19) is mounted at the end of a pin (18) inclined against the direction of movement. 4th Device according to one of claims 1 to 3, characterized in that the pin (18) on the piston bracket (12) extending across the working width rodless piston-cylinder unit (11) is attached. 5th Machine for winding material webs, in particular paper or cardboard webs, characterized in that a device according to claims 1 to 5 is attached to a lowering platform (8) for the finished winding rolls (3). 6th Machine according to claim 7, characterized in that on the lowering platform (8) below the separating device (10) extends over the working width, inflatable clamping hose (22) for Grease clamps of the web (4) is arranged on the support or support roller (1).