Adhesive bonding and miscellaneous chemical manufacture – Methods – Surface bonding and/or assembly therefor
Utility Patent
1998-05-27
2001-01-02
Crispino, Richard (Department: 1734)
Adhesive bonding and miscellaneous chemical manufacture
Methods
Surface bonding and/or assembly therefor
C156S357000, C156S356000, C156S361000, C156S378000, C700S126000
Utility Patent
active
06168679
ABSTRACT:
DESCRIPTION
1. Technical Field
The present invention relates to a device and method for measuring the diameter of a roll or reel of web material, for example paper, tissue paper or the like.
More specifically, the invention relates to a device which is especially suitable for incorporating in a gluing machine for gluing the tail end of the web material of the reel.
Gluing machines for these uses are often used in paper conversion lines where one or more large-diameter reels are turned into small rolls of paper, such as toilet paper, absorbent paper for domestic use, paper towels and so forth.
2. Background Art
In conversion lines of this kind there is often a so-called rewinder, that is, a machine that rewinds the web material into reels or rolls whose diameter is equal to the diameter of the finished product. The resulting reels are unloaded from the rewinder and passed to the next working station where the tail end of the wound material is glued down onto the outer surface of the reel, to avoid accidental unwinding during the subsequent processes of cutting the reel up into smaller rolls of the final dimension and packaging them.
There are at present many different kinds of gluing machines for gluing down the free end. Examples of such devices are disclosed in U.S. Pat. Nos. 4,026,752; 4,299,642; 4,475,974; 4,963,223; 5,242,525; in British patents nos. 1,326,043; 2,073,719; in European patent no. 0 481 929 and in the publications of international applications nos. WO-A-9515902 and WO-A-9515903. Many other sorts of gluing machines have been designed, patented and used and those listed above are only a few examples of the types of gluing machines to which the present invention may be applied, as will be seen below.
All the conventional devices known at present use a tail-end unwinding and positioning station, where the tail end of the web material is unwound, by means of various systems, and then gradually rewound by turning the reel on a pair of supporting cylinders, or the like, in the winding direction, so as to position the free end in a predetermined position detected by a sensor. Once the position is correct, the glue is applied to the web material and the free end is rewound. The application of the glue may occur in the same gluing station or in a subsequent station to which the reel is transferred by any means, without losing the reference relating to the position of the tail end. The glue is applied either to the unwound end or to the material that is still wound: the choice makes no difference for the purposes of the present invention, which applies to any gluing machine provided it includes a system for positioning the free end.
One of the critical aspects of the process of converting large-diameter reels into small rolls ready for packaging and sale is the fact that the diameter of the small roll (and hence of the reel formed by the rewinder) must be kept within certain ranges of tolerance to avoid problems during packaging. This is often difficult to achieve because of the fact that the thickness of the web material wound into the large-diameter reel is not constant and is often variable (though the variability is not known a priori) not only from reel to reel, but also within the same reel, from a greater value on the outside to a smaller value on the inside owing to the paper's being crushed. If the parameters applied during rewinding were fixed (the length and tension of the paper, the pressure applied by the movable winding roll, etc.), the reels produced by the rewinder would vary unacceptably in diameter.
It is therefore desirable to read the diameter of the reels as they are produced in order to take swift corrective action on the winding parameters and thus prevent the actual diameter of the reels from becoming too different from the theoretical reference diameter. An example of a rewinding machine and of a winding method that allow the winding parameters to be corrected is disclosed in U.S. Pat. No. 5,267,703. This is based on measuring the diameter by means of a suitable sensor when the reel is still in the rewinder.
OBJECTS OF THE INVENTION
The object of the present invention is to provide a new system of reading the diameter of reels produced by, for example, a reminder, in order to adjust the winding parameters where necessary and correct them in order to keep the diameter within a range of tolerance.
Another object of the present invention is to propose a diameter-reading method and device that can be used on a gluing machine in the paper converting line.
Yet another object of the present invention is to provide a diameter-controlling method and device that can be applied easily to existing plant, with little or no need for mechanical modifications.
Further objects and advantages of the present invention will be evident to those skilled in the art on reading the rest of the text.
DISCLOSURE OF THE INVENTION
In essence, the invention involves measuring the diameter of a reel or roll of wound web material by rotating said reel and detecting at least twice the moment when a given point on the web material passes a predetermined position. The diameter of the reel is worked out from the parameters relating to the rotation of the reel in the interval between the two passes through said predetermined position.
In practice, in one embodiment of the invention the reel can be placed on means of rotation, for example a pair of rolls, that rotate the reel, and that are provided with detection means for determining the amount said means of rotation move in the interval of time between the two moments when said given point on the web material passes said predetermined position. The diameter of the reel can be deduced from the amount of this movement.
If the rotation of the reel is brought about by means of a roll or pair of rolls, the detected movement is represented by the angle of rotation of the roll. Assuming there to be no slippage between reel and roll, the angle of rotation swept by the roll in the interval of time that elapses between the first and the second passes of the given point on the web material through the predetermined position can be used to work out the length of the circumference of the reel and hence its diameter.
In another embodiment, the invention involves measuring the diameter of a reel or roll of wound web material by rotating said reel at a known speed and detecting at least twice the moment when a given point on the web material passes a predetermined position. By measuring the time that elapses between said two passes it is possible to calculate the diameter of the reel from the values of said speed and of said time.
In theory, this method is applicable at any point in a work process in which a reel of web material is produced, or even outside the production process, for example by taking a number of samples and performing the measurements on these. Where the measurement is taken in-line, the measured reading may advantageously be used to modify the winding parameters in order to avoid departing from a predetermined range of tolerance.
The method, which may have a general application, is especially useful in paper conversion lines, as detailed above. To this end it is advantageous to apply the method of the invention at an already existing stage in the conversion process, namely in the stage of positioning the tail end of the web material prior to gluing. In this application the method involves the following steps:
a) opening the tail end of the web material wound around the reel;
b) keeping the reel rotating in the appropriate direction for rewinding the web material, and detecting the moment when a point on the web material (typically the tail end) passes a predetermined position;
c) repeating operations (a) and (b) while measuring a parameter associated with the movement of the reel, for example the time that elapses between the first and the second passes of said point through said position, or the amount of movement of the reel rotating means;
d) calculating the diameter of the reel from said parameter associated with the
Breiner & Breiner
Crispino Richard
Fabio Perini S.p.A.
Koch, III George R.
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