The present invention relates to a machine for manufacturing strands or the like, in particular a machine with a rotor which strands wires for manufacturing strands, cords, cables, ropes and the like, which are wound around a bobbin. Said machine can obviously be used inversely for unwinding strands or the like from a bobbin.
Known machines for manufacturing strands or the like comprise a support for supporting a bobbin, wherein a rotor can rotate around a main axis for stranding one or more wires and winding around the main axis, namely around the bobbin, a strand obtained by stranding these wires. The support of the bobbin can move along the main axis for obtaining an axial relative motion between the first support and at least one portion of the rotor, so as to uniformly distribute the strand around the bobbin. The support supports the bobbin from one side only, since a second support arranged on the opposite side and fixed to the first support would interfere with the rotation of the rotor and/or with the strand which is wound by the rotor around the bobbin. Since the bobbin is supported only from one side, big bobbins cannot be used and/or heavy strands cannot be wound. For overcoming this disadvantage the diameter of the point of the support which penetrates into the bobbin must be much greater (for example 200 mm) of the diameter (for example 80 mm) of the standard points, so that bulkier and non-standard bobbins must be used.
Other known machines comprise two supports which support the bobbin without moving it axially and a rotor provided with a pulley which transmits the strand from the rotor to the bobbin by moving along the rotor with an alternate motion in a direction parallel to the main axis, for uniformly distributing the strand around the bobbin. The rotor of said known machines is heavier and bulkier, since it must also comprise the mechanical and electrical means for moving said pulley, with a consequent increase of size, cost, electrical consumptions and risk of accidents or malfunctions. Furthermore, the feeding speed of the wires and the strand must be changed for compensating the movement of the pulley, with consequent problems of control and/or quality of the strand.
Further known machines comprise two supports which support the bobbin without moving it axially and a rotor which moves with an alternate motion in a direction parallel to the main axis, always for uniformly distribute the strand around the bobbin. These known machines have substantially the same disadvantages of said machines with translating pulley.
JP 07-003676 A, FR 1384772 and the first embodiment of EP 732441 A2 disclose machines comprising a longitudinal shaft which supports the bobbin, can move along the main axis and protrudes beyond the bobbin, thereby penetrating into a corresponding seat made in the rotor. U.S. Pat. No. 2,817,948 discloses a similar machine comprising a hollow longitudinal shaft which supports the bobbin, can move along the main axis and is provided with a longitudinal seat in which a further longitudinal shaft protruding from the rotor is arranged. In these four known machines the bobbin is pulled or pushed along the main axis only from the side opposite to the rotor, so that the control of the movement of the bobbin is relatively limited, with possible malfunctions especially when the bobbin is big and made heavy by the strand wound around it.
For overcoming the latter technical problem, the longitudinal shaft of the second embodiment of EP 732441 A2 protrudes beyond the rotor, so that both ends thereof can be simultaneously pulled or pushed by transmission members which are mutually connected by a longitudinal bar for being pushed or pulled along the main axis by a single motor. Said longitudinal shaft is interrupted where the bobbin is arranged, which bobbin is thus supported by the ends of the interrupted shaft. Said ends can be mutually fastened by a slidable connection rod which crosses the bobbin along the main axis. Since the bobbin must rotate around the main axis with a different speed with respect to the rotor, also said longitudinal shaft must rotate at a different speed with respect to the rotor. However, the second embodiment of EP 732441 A2 cannot work, since the portion of the longitudinal shaft arranged in the rotor interferes with the latter due to their different rotation speeds and to the pulley which takes the wires to be stranded from an axial cavity in the longitudinal shaft to the outside of the latter. In other words, the longitudinal shaft of the second embodiment of EP 732441 A2 could only rotate at the same speed of the rotor.
It is therefore an object of the present invention to provide a machine which is free from said disadvantages. Said object is achieved with a machine, whose main features are disclosed in the first claim, while other features are disclosed in the remaining claims.
Thanks to the particular second support of the bobbin, the machine according to the present invention can not only comprise a rotor which is relatively simple, light and less bulky, but can also support heavy bobbins and/or strands by using standard points.
The first and the second supports preferably support the bobbin in a rotatable manner, in particular by rotating the bobbin around the main axis without using a longitudinal shaft as in the prior art, and move along the main axis with an alternate motion, while the rotor rotates only around the main axis, so as to reduce the structural complexity of the machine and increasing its speed in the manufacture of strands.
The mutual distance between the two supports is preferably controlled and kept constant by a particular mechanical connection, so as to move axially also a heavy bobbin, while keeping it always in the correct position with respect to the rotor.
Further, the supports are preferably provided with particular mobile points for facilitating the mounting and the unmounting of the bobbins.
Thanks to its particular mechanical structure, the first support comprises all the means for rotating the bobbin, including the motor, so as to keep the bobbin always close to the first support and avoid a disadvantageous lever effect of the bobbin onto the first support, as instead happens in the second embodiment of EP 732441 A2.
According to a particular embodiment of the invention, the first support can move along the main axis in a manner independent from the second support, so as to easily mount and unmount bobbins having different widths.
Further advantages and features of the machine according to the present invention will become clear to those skilled in the art from the following detailed and non-limiting description of five embodiments thereof with reference to the attached drawings, wherein:
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First support 1 can move axially with an alternate movement (shown by arrow 12) along main axis 3 for uniformly distributing strand 8 around bobbin 2. In the present embodiment, rotor 5 is provided with a main body 13 which can rotate around main axis 3 thanks to second motor 6 but cannot move axially with respect to a fixed base 14. First support 1 can instead move along main axis 3 on one or more rails 15 of base 14.
Rotor 5 is provided with a second support 16 which can move along main axis 3 for supporting bobbin 2 in a rotatable manner around main axis 3, in such a position that bobbin 2 is arranged between first support 1 and second support 16. Second support 16 rotates with rotor 5 around main axis 3. First support 1 is mechanically connected to second support 16, so as to control the mutual distance between first support 1 and second support 16 during the rotation of rotor 5, in particular by controlling that this mutual distance is substantially constant. Second support 16 is arranged coaxially in main body 13 of rotor 5. Wires 7 get in from one end of second support 16 along main axis 3 and come out from a lateral opening 17 of second support 16 after they have been guided and stranded by main pulley or roller 9, which is pivoted to main body 13 for rotating both around its own axis and around main axis 3 in lateral opening 17. In particular, second support 16 has a substantially cylindrical shape, so as to balance its weight with respect to main axis 3. A tooth 30 fixed to rotor 4 protrudes in lateral opening 17 of second support 16 so that second support 16 rotates with rotor 5.
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For mounting bobbin 2 on supports 1, 16, the latter are moved axially so as to insert second point 20 into bobbin 2, after which first point 18 is moved axially in the opposite direction, so that first point 18 penetrates into bobbin 2, which results then centered between points 18, 20. For unmounting bobbin 2 the same operations are carried out inversely.
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It is obvious that the machine according to the present invention can be used in an inverse manner, namely for unwinding a strand or the like from the bobbin, thereby stranding it for loosen the wires or taking it without torsions to another machine which rotates at the same speed.
Further modifications and/or additions may be made by those skilled in the art to the hereinabove disclosed and illustrated embodiments while remaining within the scope of the following claims.
Number | Date | Country | Kind |
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MI2009A000248 | Feb 2009 | IT | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2010/051870 | 2/15/2010 | WO | 00 | 9/16/2011 |