Winding – tensioning – or guiding – Convolute winding of material – With cutting – perforating – or notching
Reexamination Certificate
2000-01-28
2001-10-23
Walsh, Donald P. (Department: 3653)
Winding, tensioning, or guiding
Convolute winding of material
With cutting, perforating, or notching
C242S532200
Reexamination Certificate
active
06305635
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to a method for winding a continuous web of material onto a series of core mandrels, to a device for cutting the web on changing the core mandrels, to a web winding device and to the application of the method.
BACKGROUND OF THE INVENTION
Web winders and web winding methods are known in various embodiment forms and are e.g. described in DE-A 2 243 504, EP-A-0 017 277, EP-A-0 394 197 and CH-A-683 992 and the state of the art is described in these documents. Common to the known winders is that a relatively quick running and more or less endless material web of plastic foil, paper textile material or another relatively thin (typically 10 to 1000 &mgr;m thick) and flexible material with working widths of up to a few meters either in the course of the manufacture of the web material or with its processing must be continuously wound, i.e. without interruption of the flow of material, onto a series of core mandrels which are fed to the winder from a winding reel magazine.
With this there are in particular two problems to be solved, specifically on the one hand a very rapid, clean and precise separation or cutting procedure is to be effected and on the other hand the front end of a new web section is to be brought into winding contact with a fresh, i.e. empty core mandrel. An approximately right-angled cutting procedure with high web running speeds may only be achieved with a knife acting suddenly, e.g. within 0.1-0.5 seconds, over the whole web width, which with web winders for the production or processing of typical technical plastic foils is mostly a serrated knife, as is described in CH-A-674 352. According to the transverse cutting method described in the above mentioned patent document DE-A-2 243 504 a knife or blade with a relatively high speed is guided transversely over the material web, which leads to an oblique cut.
For achieving the winding contact for the winding of a core mandrel which is still empty usually adhesives or adhesive tapes are used. This in practice has various disadvantages such as the lessening of the effectiveness of the adhesive layers by dust, the unwanted contamination of adhesive or adhesive tape into the winding and the use of organic solvents. Suggestions for achieving the winding contact by way of electrostatics, such as e.g. in EP-A- 0 270 498 and the state of the art described therein have not been able to be sustained in practice up to now on account of the required high voltages and the consequences of a change in air humidity.
A common disadvantage of the known methods and devices is a more or less heavy jerk with the winding procedure which may lead to disadvantageous effects on premounted, i.e. on the upstream side manufacturing, processing or refining units.
BRIEF SUMMARY OF THE INVENTION
It is the object of the invention to offer a winding method which does not have the mentioned disadvantages or only to a negligible extent. The object of the invention is also an improved cutting device and a new web winder.
These objects are according to the invention achieved by a method for winding a continuous web of material onto a series of core mandrels of a winding device which has a winding roller, at least one movable deflection roller and a cutting device, characterised in that the front end of the web formed on actuation of the cutting device, under the effect of an arc-shaped airstream which extends around at least roughly a quarter of the spool circumference, at least approximately over the width of the core mandrel and up to the vicinity of the contact line between the winding roller and the bearing core mandrel, is brought into winding contact with the core mandrel.
The description “winding contact” used here means a contact between the core mandrel and the new front web end formed by cutting the web, which is sufficient for winding a fresh core mandrel.
The speed of the airflow is preferably twice in particular three times and e.g. six times greater than the material web running continuously with web running speeds of 30 to 400 meters/minute or more.
Preferably every winding roller, thus that of the preceding finished winding as well as that of the fresh subsequent winding is connected to a central drive which may be controlled such that the tensile stress acting on the web may be kept to a desired value and is not dependent on the thickness of the respective winding. In a useful manner for this a drive acting from the left side and one from acting the right side of the winder is used.
Preferably the arc-shaped airstream is produced by a reduced pressure, e.g. from −450 to −900 millibar, acting in the vicinity of the contact line between the winding roller and the core mandrel bearing on this. According to a preferred embodiment form of the method the formation of the arc-shaped airstream is supported by lateral afflux streams which are produced by the pressure difference between the applied reduced pressure and the surrounding pressure, or a hyperbaric pressure from an excess pressure source.
Generally it is preferred that the web on actuation of the cutting means contacts the core mandrel over roughly half its circumference.
In order to make the cutting procedure practically jerk-free, it is useful to keep the web path, with the help of a reduced pressure applied in the inside of the winding roller, on the winding roller provided with openings of the roller casing. For improving the contact of the web with the core mandrel in the inside of the core mandrel provided with openings there is applied a reduced pressure.
The cutting device according to the invention, for a device for winding a continuous web of material onto a series of core mandrels is characterised in that the cutting device has a reduced pressure channel which extends practically over the length of the core mandrels and which is connected to a guiding wall encompassing in an arc-shaped manner the core mandrel about at least a quarter of its circumference and to a serrated knife, in order to bring the front end of the web, which is formed on actuation of the cutting means, under the effect of an arc-shaped airstream extending at least around a quarter of the spool circumference at least approximately over the width of the core mandrel and up to the vicinity of the contact line between the winding roller and the bearing core mandrel, into winding contact with the core mandrel. Preferably the cutting means is connected to a means for pivoting the knife into the path of the web between a fresh core mandrel bearing on the winding roller and a movable winding roller which is brought into a position near to the core mandrel.
The device, according to the invention, for winding a continuous web of material onto a series of core mandrels includes a winding roller, at least one movable deflecting roller and a means for severing the web in order on this to form a web end thereon passing onto a preceding full core mandrel and a web end envisaged for winding on the subsequent empty core mandrel, and is characterised in that the cutting device has a reduced pressure channel which extends practically over the length of the core mandrels and which is connected to a guiding wall encompassing in an arc-shaped manner the core mandrel about at least a quarter of its circumference and to a serrated knife, in order to bring the front end of the web, which is formed on actuation of the cutting means, under the effect of an arc-shaped airstream extending at least around a quarter of the core mandrel circumference at least approximately over the width of the core mandrel and up to the vicinity of the contact line between the winding roller and the bearing core mandrel, into winding contact with the core mandrel.
Preferably the winding roller (
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) has a casing provided with a rubber coating, e.g. of steel, and openings, in order by way of a reduced pressure prevailing in the inside of the winding roller to hold a bearing web in reinforced contact and to permit a practically jerk-free winding operation.
Finally the invention relates also to th
Blank Rome Comisky & McCauley LLP
Schlak Daniel K
Walsh Donald P.
Windmoeller & Hoelscher KG
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