Method and system for feeding a twisted braided metal cable or flat wire from a corresponding support without altering the structure or shape of the wire

Abstract

Method and system for feeding a twisted metal cable braided into a plurality of braids or a flat wire from a support or spool to a winder or winding machine, including unwinding the cable or wire from the spool, measuring a property of the cable or wire from among its tension, velocity and quantity, possible adjustment of the property and feeding the cable or wire to the machine with the property constant. The cable or wire is unwound in a controlled way in a direction at right angles to the axis of the spool directly from such spool or through a return member which receives the cable or wire from the spool from which it is unwound in an uncontrolled way, such controlled unwinding preventing the cable changing the structure of its braids through loosening or stretching and the wire undergoes torsion before its property is measured.

Claims

1. A method for feeding a metal cable twisted and braided into a plurality of braids or a flat wire from a spool to an operating machine which processes the cable or wire, said feeding comprising unwinding the cable or wire from the spool, wherein the spool is supported by a supporting member, wherein the spool has a longitudinal axis aligned with the supporting member, measuring at least one monitored property of the cable or wire from among its tension, velocity and quantity delivered, sending information related to the feed velocity of the wire or cable to the operating machine via a communication bus, any adjustment of the property and feeding of the cable or wire to the operating machine with the aforesaid property being held constant, the cable or wire being unwound in a controlled way in a direction at right angles to the longitudinal axis of the spool, wherein the controlled unwinding takes place by unwinding the cable or wire from the spool in an uncontrolled way but subsequently passing the cable or wire leaving the spool over a return member located at a short distance from such spool and associated with the supporting member for the spool to immediately stop ballooning movement of the cable or wire, wherein the spool is driven in rotation in an unwinding direction about its own longitudinal axis by its own electric motor associated with said supporting member, said driving being obtained at a velocity such as to maintain the unwinding of the cable or wire at right angles to the axis of the spool, this controlled unwinding preventing the cable from changing its structure through loosening or stretching or preventing said wire from suffering twisting before its property is measured, said cable or said wire maintaining its own structure from spool to the operating machine.

2. The method according to claim 1, further comprising a sensor for measuring the monitored property of the cable or wire that is directly on said return member.

3. The method according to claim 1, wherein the return member extends from the supporting member, wherein the controlled unwinding takes place by passing the cable leaving the spool over a portion of the return member positioned with an axis parallel to the axis of the spool.

4. The method according to claim 3, wherein the at least one monitored property of the cable or wire is monitored by a device feeding the cable or wire located between the spool and the operating machine, said feed device controlling a braking torque applied to the electric motor rotating said spool.

5. The method according to claim 3, wherein the electric motor is within the supporting element.

6. The method according to claim 1, wherein the cable or wire unwinds from the spool with the controlled property being held constant during said unwinding.

7. The method according to claim 1, wherein the at least one monitored property of the cable or wire is monitored by a tensioning member located between said spool and the operating machine.

8. The method according to claim 1, wherein the at least one monitored property of the cable or wire is monitored by a tension and/or velocity sensor member close to the spool.

9. The method according to claim 1, wherein the cable or wire is unwound from the spool and subsequently passes within an eye of the return member within the portion of the return member positioned with an axis parallel to the axis of said spool.

10. The method according to claim 1, wherein the controlled unwinding takes place by passing the cable leaving the spool from the spool to directly over the return member located at the short distance from such spool and associated with the supporting member for the spool.

11. A system for feeding a twisted braided metal cable or a flat wire to an operating machine which processes it, said system implementing the method according to claim 1 and comprising a spool for such cable or wire, a supporting member to support the spool, wherein the spool has a longitudinal axis aligned with the supporting member, means to measure at least one monitored property of the cable or wire from among its tension, its feed velocity or quantity of wire delivered, means to provide monitoring of any measured property and for feeding said cable or wire to said machine holding said at least one property at a constant value, the cable or wire detaching itself at right angles from such spool with reference to the longitudinal axis of said spool, wherein a return member for the cable or wire is provided close to the spool which controls detachment of the wire from such spool at right angles by passing the cable leaving the spool over the return member located close to the spool, said return member being associated with the supporting member for said spool, said cable or wire having the braided structure or flat conformation which remains unchanged at least from such time as its property is measured as far as the operating machine adapted and configured such that the cable or wire is unwound in a controlled way in a direction at right angles to the longitudinal axis of the spool, wherein the controlled unwinding takes place by unwinding the cable or wire from the spool in an uncontrolled way but subsequently passing the cable or wire leaving the spool over a return member located at a short distance from such spool and associated with the supporting member for the spool to immediately stop ballooning movement of the cable or wire, and adapted and configured such that said spool is driven by its own electric motor associated with the supporting member for the return member, said spool being driven in rotation in an unwinding direction about its own longitudinal axis by such electric motor at a constant velocity.

12. The system according to claim 11, wherein the metal cable or the flat wire has an unchanged structure from the spool from which it is unwound, to the operating machine.

13. The system according to claim 11, wherein the return member extends from the supporting member, wherein the cable leaving the spool passes over a portion of the return member positioned with an axis parallel to the axis of said spool.

14. The system according to claim 13, wherein the means for measuring the monitored property are a feed device for the cable or wire to the operating machine, said feed device applying a braking torque to the electric motor rotating said spool.

15. The system according to claim 14, comprising the feed device, wherein the communication bus connects such feed device to the operating machine so that information relating to the feed velocity of the wire or cable to that machine can be used to maintain said cable or wire at a desired tension upstream of the feed device itself.

16. The system according to claim 14, comprising a feed device, further comprising a second feed/tensioner device operating synchronously with the first feed device.

17. The system according to claim 11, wherein the means for measuring the monitored property is a tension sensor member close to the spool.

18. The system according to claim 11, wherein said return member comprises a tension sensor.

19. The system according to claim 11, wherein the return member has an eye for passing the cable or wire unwound from the spool within the eye.

20. The system according to claim 11, adapted and configured for the cable leaving the spool to pass from the spool directly to the return member.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a better understanding of this invention the following drawings are appended purely by way of non-limiting example, in which:

(2) FIG. 1 shows a diagrammatical view of a first system according to the invention;

(3) FIG. 2 shows a diagrammatical view of a second system according to the invention; and

(4) FIG. 3 shows a diagrammatical view of a third system according to the invention.

(5) FIG. 4 shows a diagrammatical view of a fourth system according to the invention.

(6) FIG. 5 shows a diagrammatical view of a system feeding the wire upstream of a second feed/tensioner device.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(7) With reference to the above-mentioned figures, the present invention mainly relates to the fact that it has been found that structural change in a multistrand metal cable (that is one comprising a plurality of braided individual wires) or flat cable drawn from a corresponding support (for example, a spool) happens because of the manner in which that cable or wire is unwound from the corresponding support. The object of the invention is therefore to define a manner of unwinding and a system such that the problem indicated above can be overcome.

(8) According to the invention a system 1 comprises a support or spool 2 supporting a multistrand metal cable 3. This cable 3 is drawn from spool 2 and passes through an intermediate device 4 located between the cable spool 2 and an operating machine 5 such as, for example, a winding machine (or winder) 5 or a textile machine 5.

(9) Device 4 may be of the type such as to feed the cable to machine 5 independently or may be a mere tensioning device capable of creating a particular desired set tension in cable 3. In the first case device 4 is for example of the type described in WO2013/064879 in the name of the Applicant, and acts actively to draw cable 3 from spool 2 and feed it to machine 5; conversely, in the second case, the wire is drawn off through other known means (not shown) which feed it to a machine 5, and device 4 is a tensioner or a braking device which can bring about an increase in the tension of the cable downstream from device 4 itself.

(10) In the first case the device (feeder 4) delivers cable 3 to the operating machine, maintaining at least one property of the cable (selected from its tension, feed velocity and quantity fed) equal to at least one predefined pre-set (constant) value.

(11) In a manner of feeding which is not the subject of the method according to the invention, cable (or flat wire) 3 is unwound from spool or support 2 in a controlled way tangentially to the spool itself (or better, tangentially to the mass of cable 3 wound on the spool) with respect to the W axis of support 2. The latter may be fixed or rotate about such axis.

(12) In other words, cable 3 is unwound from spool 2 in a direction at right angles to that axis. It is known that the term “at right angles” comprises both unwinding at a right angle with respect to such axis, but also unwinding inclined at ±45° with respect to the W axis. Furthermore, by unwinding in a “controlled way” is meant that cable 3 does not detach from the spool forming a balloon around it (that is in an “uncontrolled” way), a balloon which expands as the spool is emptied. On the contrary, the cable detaches from the spool already under tension, without any movement around the W axis mentioned above. This means that cable 3 does not move in a way which might vary its structure (as indicated above), but maintains the structure, being unable to rotate in a direction opposite to that of the braid of individual wires or in the direction of the braid.

(13) According to one embodiment of the invention (shown in the figures), the cable (or flat wire) is unwound from the spool in an uncontrolled way, but subsequently passes over a return member 10 (or better, within an eye 10A of such return member, as shown in FIGS. 1-3) located at a short distance from spool 2 positioned with axis K parallel to the latter's W axis. In this way the ballooning movement of the wire is immediately stopped without having any effects on the structure; after return member 10, the wire moves at right angles to the W axis of the spool, which means that it avoids stretching or “separation” of the braided wires. Member 10 is associated with supporting body or member 14 which also supports spool 2 and, for this reason, is located at a short distance from the latter.

(14) Advantageously, the system provides that spool 2 is supported by supporting member 14 and driven by its own electric motor 15 (contained within support 14) which is activated in such a way that said spool 2 can rotate at a controlled speed, encouraging release of cable 3 in the manner indicated above. This avoids the cable altering its structure (stretching or creating whiskers) or the flat wire from forming a helix.

(15) The solution envisaged in the present invention is of the passive type in that it does not actively act on the wire feed, neither is it implemented so as to detect a specific property or shape or change in the structure or shape of delivered cable 3.

(16) Arm 10 receives such cable passing through its eye 10A, and only because of the fact that it is located at a short distance from spool 2 is it able to maintain the structure of said cable with certainty, in that it avoids the ballooning effect of the cable about such spool, an effect which, as mentioned, is the cause of a change in the structure of the delivered cable.

(17) In addition to this, the system can operate in one of the following ways. In a first way it is provided that wire feed/tensioner device 4 sends information relating to the feed velocity of wire or cable 3 to the operating machine 5 via a suitable communication bus 51 (configured to transmit a signal), acting so that such wire or cable always remains tensioned upstream from the feed device, avoiding loosening or tearing during the stage when the feed/tensioner device is decelerating and accelerating.

(18) In a second way feed/tensioner device 4 for wire or cable 3 controls the braking torque applied to electric motor 15 so as always to rotate spool 2 in such a way as to prevent tearing/loosening during the stages in which the wire fed to the process accelerates or decelerates.

(19) In a third configuration, provision is made for a sensor 34 (e.g., a tension sensor, a velocity sensor, or a combined tension and velocity sensor) located between spool 2 and feed/tensioner device 4, so that wire or cable 3 does not undergo any loosening or extra tensioning as it runs out respectively during the stages in which the wire or cable fed to the process is slowed/accelerated. In this case, device 4 may operate either independently, feeding the wire to machine 5 directly, or feeding it upstream of a second feed/tensioner device 4 (FIG. 5), synchronously therewith, through exchanging information on the wire's or cable's velocity and/or torque and/or feed tension to the production process performed by machine 5.

(20) Therefore, according to the invention, cable or wire 3 is unwound from support or spool 2 and immediately acts together with arm 10 in a way such that it does not change its structure (or, as mentioned, being stretched or giving rise to loosened whiskers, or taking up a helical shape in space) at least from the time when one of its properties (tension, velocity, quantity delivered) is measured until operating machine 5 processes it. Preferably, with this property being held constant from the time that cable 3 is unwound from spool 2, the structure of such cable or flat wire remains unchanged from the time that it is unwound from the spool to textile machine 5.

(21) In addition, cable (or wire) 3 is fed to machine 5 with at least one of its properties held constant, that is its tension and/or velocity (but also the quantity of wire delivered), and this ultimately makes it possible for cable 3 to be drawn off from spool 2 in such a way that its structure is not altered. In fact, for example, by keeping the cable or wire tensioned or feeding it to machine 5 without tearing, cable 3 or the flat wire is always unwound from support or spool 2 in such a way that the direction in which the wire is drawn off is always at right angles to the W axis of the spool, because of the presence of member 10.

(22) One embodiment of the invention has been described. Others are yet possible in the light of the above, such as that in which return member 10 (also acting as a wire guide) may comprise a tension sensor 103 (FIG. 3) connected to feed device 4 so that the latter can have more data to control the drawing-off of cable or wire 3 from spool 2.

(23) Thanks to the system according to the invention, the problem associated with the changes in the structure of cable or wire 3 described above is overcome.