Patent Application
20130214082
This application claims priority to Italian Patent Application No. MI2012A000229, filed on Feb. 16, 2012, the content of which is hereby incorporated by reference in its entirety.
The present invention relates to a method for precisely cutting to size tubes wound onto a spool and a tube winding machine which implements this method.
It is known in the technical sector relating to the winding of tubes, hanks and the like onto spools that this is achieved by winding the hank onto a reel rotating on a motor-driven hub of a winding machine.
It is also known that in the art there exist different designs of winders for automatically winding tubes made of plastic and other materials, these winders operating with a completely automatic cycle comprising substantially the following steps:
It is also known that one of the problems associated with these methods for winding tubes onto spools consists in the need to have precise measurements of the wound tube so as to obtain spools with a uniform and predefined tube length.
It is also known that, in order to perform cutting to size of the wound tube, the known art envisages using devices for measuring the tube fed to the winding machine and made to pass through a predefined arrival gate.
These known measuring and cutting methods, however, have the drawback arising from the fact that the measuring device is situated at a large distance from the cutting device, which is instead arranged on the machine, this resulting in a high degree of imprecision due to the longitudinal deformations of the tube which inevitably expands/retracts along the path between the measuring device and cutting device, resulting, after completion of winding, in spools with a length which is not uniform or in any case incorrect.
Further measuring and cutting methods use synchronization means with metre-counting wheels which are prone to frequent decalibration which alters the precision of the measurement and requires maintenance with consequent machine downtime.
Examples of the prior art are described in U.S. Pat. No. 4,385,426 and NL 137,753.
The technical problem which is posed, therefore, is that of developing a method and an apparatus for winding tubes and the like onto a spool, which allow precise cutting of the length of the wound tube in order to obtain spools with a constant and uniform length, irrespective of any possible deformations of the tube during winding.
In connection with this problem it is also required that this apparatus should have small dimensions, be easy and inexpensive to produce and assemble and be able to be installed easily at any user location also on already existing machines using standardized means.
These results are achieved according to the present invention by a method for winding and wrapping spools of tubes according to the characteristic features of Claim 1 and by a machine for winding and wrapping spools of tubes according to the characteristic features of Claim 3.
Further details may be obtained from the following description of a non-limiting example of embodiment of the subject of the present invention provided with reference to the accompanying drawings in which:
As shown in
The machine also has, mounted thereon, a device 30 for detecting a marking 1b which, as will emerge more clearly below, is applied onto the tube 1, which device is arranged upstream of the cutting blade 12 and at a predefined distance D from the cutting blade 12.
As shown, the machine is completed by a unit 20 for measuring the length of the tube 1, which comprises:
The marking may consist of different types, for example invisible, coloured or conductive paint, microchips or the like, but in any case must be such that it may be detected by the device 30 for detecting the marking 1b.
According to the invention it is also envisaged that the sequences and operations of the machine and the measuring unit are performed by means of a control and operating device 1000 connected to transducer means for detecting signals emitted by sensors and controlling operations which may be electrical, hydraulic or equivalent, conventional per se and not shown or described in detail.
With this machine configuration a method for precisely cutting to size a tube fed to a winding machine equipped with a reel 11 and at least one cutting blade 12 comprises the following steps:
It is therefore clear how, according to the invention, it is possible to provide the measuring and marking unit 20 at any more suitable distance from the machine 10 in keeping with the logistical requirements for installation of the entire plant; as shown, tube guide supports 2 may be arranged between the measuring unit and the winding machine. Said distance of the measuring and marking unit 20 from the machine 10, even if considerable, does not adversely affect, however, the cutting precision at the predefined measured length, since the marking sensor arranged on the machine at a predefined small distance D from the cutting blade always and in any case detects precisely the marking 1b, sending a consent signal to the control unit 1000 which operates said blade at the right time determined by the tube feeding speed and the corresponding distance D which are known to the control unit 1000.
The length of the tube wound onto the spool is therefore independent of any deformations of the tube which may alter the measuring precision and therefore the effective length of the spool.
Bearing in mind that this type of machine processes with a continuous cycle very large quantities of tube, being able to have a precise measurement of the length of the wound tube avoids more tube being wound than the programmed amount calculated when performing the cost evaluation of the spool, thereby avoiding manufacturing losses.
Although described in connection with certain constructional forms and certain preferred examples of embodiment of the invention, it is understood that the scope of protection of the present patent is defined solely by the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| MI2012A000229 | Feb 2012 | IT | national |
