WO2013088221A1

WO2013088221A1 - Device for feeding a yarn to a textile machine

Info

Publication number: WO2013088221A1
Application number: PCT/IB2012/002643
Authority: WO
Inventors: Tiziano Barea
Original assignee: Btsr International S.P.A.
Priority date: 2011-12-15
Filing date: 2012-12-07
Publication date: 2013-06-20
Also published as: DE212012000228U1; ITMI20112270A1; CN204057447U

Abstract

A device for feeding yarn to a textile machine, comprising a main body (2); a rotatable drum (5) having a lateral surface (5s) to rest against a yarn bobbin (B); a motor (6) connected to said drum (5) and fixed to said main body (2); and a support structure (8) for said drum (5) rigidly fixed to said motor (6) and positioned in the interior of said drum (5).

Description

DEVICE FOR FEEDING A YARN TO A TEXTILE MACHINE

DESCRIPTION

The present invention relates to a device for feeding yarn to a textile machine in accordance with the introduction to the main claim.

In particular, the present invention relates to a feed device of rolling takeoff type, i.e. a feed device which acts directly on a yarn spool, to rotate it by an action on a lateral surface of the spool itself.

Known rolling takeoff feed devices comprise a support on which the yarn spool is positioned, together with a rotary drum which is driven by a suitable motor and brought into contact with the spool.

The external surface of the drum is coated with a material ensuring sufficient grip on the spool to drag it into rotation.

In greater detail, the motor presents a shaft on which the drum is juttingly fixed.

The drawback of this configuration is that it considerably limits the drum length. In this respect, if the drum were to have an excessive length, its weight would tend to flex it, causing misalignment between the shaft and the motor. This misalignment generates undesired stresses on the motor, which undergoes progressive damage which remains barely discernible until its final breakage.

To obviate this drawback, known feeders can comprise a support structure to which the drum is connected. In detail, the support structure comprises two parallel brackets, each connected to a respective drum end.

In this manner, the support structure supports the drum and avoids undesirable flexures which can damage the motor. With this solution, drums of considerable dimensions can be used.

However this solution also presents certain drawbacks.

As the distance between the brackets is fixed, the drum length is also fixed. In other words, when the need arises to change the drum length (when spools of different dimensions are present), the respective support structure must also be available for change-over.

Moreover, the support structure presents a not inconsiderable weight and bulk which can generate certain problems when the feed device is mounted on the textile machine.

In this context, the technical aim at the basis of the present invention is to propose a device for feeding yarn to a textile machine which overcomes the drawbacks of the aforesaid known art.

A particular object of the present invention is to provide a device for feeding yarn to a textile machine which is extremely versatile and reliable, such as to be able to adapt easily to different operative requirements without increasing the risk of breakage or faults.

A further object of the present invention is to propose a device for feeding yam to a textile machine which is able to support large dimension spools without causing damage to the feed device itself.

The stated technical aim and the specified objects are substantially attained by a device for feeding yarn to a textile machine comprising the technical characteristics expounded in one or more of the accompanying claims.

Further characteristics and advantages of the present invention will be more apparent from the indicative and hence non-limiting description of a preferred but non-exclusive embodiment of a device for feeding yarn to a textile machine, as illustrated in the accompanying drawings, in which:

Figure 1 is a perspective view of a device for feeding yarn to a textile machine in accordance with the present invention;

Figure 2 is a lateral view of the feed device of Figure 1 ;

Figure 3 is a section through the feed device of Figure 1 taken on the section line ll-ll of Figure 2;

Figure 4 is a section through the feed device of Figure 1 taken on the section line Ill-Ill of Figure 2; and

Figure 5 is an exploded perspective view of a detail of the feed device of Figure 1.

With referenced to the accompanying figures, the reference numeral 1 indicates overall a device for feeding yarn to a textile machine in accordance with the present invention.

The device 1 comprises a main body 2 having a connection member (not shown) for connecting the device 1 to a textile machine (not shown).

The device 1 comprises a support element 3 on which, when in use, a yarn bobbin B is mounted and which is associated with the main body 2.

The support element 3 extends along its main development axis A and presents a plurality of radial portions 4 which extend away from the main development axis A.

The tubular support of the bobbin B, for example of cardboard, is drawn over and fixed onto the radial portions 4.

The support element 3 is rotatable about its main development axis A and is idle. In other words, the bobbin B is idly rotatable about the main development axis A of the support element 3.

The device 1 also comprises a rotatable drum 5 connected to the main body

2 and associated with the bobbin B to cause it to rotate.

In detail, the drum 5 extends along its main development axis which is disposed parallel to the development axis A of the support element 3.

The drum 5 presents a lateral surface 5s which, when in use, rests on a lateral surface of the bobbin B. In greater detail, the lateral surface 5s of the drum 5 is coated with a material which ensures good adhesion between the drum 5 and bobbin B. For example the lateral surface 5s of the drum 5 is coated with rubber.

The device 1 also comprises a motor 6 fixed to the main body 2 and connected to the drum 5 to rotate it. In particular, the motor 6 comprises a motor shaft 7 disposed along (and rotating about) a motor axis M. Consequently, rotation of the drum 5 determines rotation of the bobbin B which, in this manner, unwinds the yarn required for the textile machine operation.

The drum 5 is connected to the main body 2 by a support structure 8.

According to the present invention, the support structure 8 is connected rigidly to the main body 2 and is also disposed in the interior of the drum 5. Preferably, the support structure 8 is fixed directly to the motor 6 which, as shown, is connected to the main body 2. Even more preferably, the support structure 8 is fixed to a box housing containing the motor 6. In a non- illustrated embodiment, the support structure 8 is directly fixed rigidly to the main body 2.

Preferably, the support structure 8 is disposed completely in the interior of the drum 5. With reference to that illustrated, the support structure 8 comprises a sleeve 9 disposed coaxially to the drum 5.

The sleeve 9 extends along its main development axis which, when in use, coincides with the motor axis M. The sleeve 9 presents a first end 9a and a second end 9b opposite the first.

The sleeve 9 is associated with the drum 5 at its first end 9a and at its second end 9b. In detail, the first end 9a of the sleeve 9 is associated with the first end 5a of the drum 5, while the second end 9b of the sleeve 9 is associated with the second end 5b of the drum 5.

In greater detail, a coupling flange 10 is disposed at the front end 9a of the sleeve 9. The flange 10 faces and is in contact with the motor 6 to form a rigid connection between the sleeve 9 and the motor 6.

For example, in the described embodiment, the flange 10 is fixed to the motor 6 by three screws 1 1 passing through three corresponding angularly equidistant holes 12 provided in the flange 10. It should be noted that in

Figure 4, only one screw 1 and a corresponding hole

12 are visible.

The support structure 8 also comprises a transmission shaft 13 rotatably connected to the sleeve 9.

In particular, the transmission shaft 13 is disposed coaxially to the motor axis

M and comprises a first end 13a and a second end 13b opposite the first.

The first end 13a is connected to the motor 6. In detail, the first end 13a of the transmission shaft 13 is connected to a free end of the motor shaft 7.

The connection between the motor shaft 7 and the transmission shaft 13 can be of rigid type. Alternatively, a flexible coupling (not shown) can be interposed between the motor shaft 7 and the transmission shaft 13.

The second end 13b of the transmission shaft 13 is instead connected to the drum 5 at its second end 5b. In this manner, the transmission shaft 13 transmits rotation from the motor 6 to the drum 5.

In detail, a connection piece 14 is disposed inside the drum 5 and presents a hole in which the transmission shaft 13 is keyed and fixed at its second end

13b by means for example of a screw 17. In greater detail, the second end

13b of the transmission shaft 13 extends beyond the longitudinal extension of the sleeve 9, the connection piece 14 facing the second end 9b of the sleeve 9.

In order to support the transmission shaft 13 within the sleeve 9, the support structure 8 comprises a pair of bearings 15 disposed between the sleeve 9 and the transmission shaft 13.

In greater detail, one of the bearings 15 is disposed between the first end 13a of the transmission shaft 13 and the first end 9a of the sleeve 9, while the other bearing 15 is disposed between the second end 13b of the transmission shaft 13 and the second end 9b of the sleeve 9.

Preferably, the bearings 15 are ball bearings.

The bearings 15 are positioned in suitable seats defined by annular recesses provided in an inner surface of the sleeve 9 and retained in these seats by respective retaining rings (or seeger rings) 16.

A further bearing 25 is positioned between the drum 5 and the sleeve 9 at the first end 5a of the drum 5. In detail, the further bearing 25 is positioned on a cylindrical portion of the sleeve 9 jutting from the flange 10.

With reference to the support element 3, it should be noted that this is movable and specifically translatable along a linear trajectory. In fact, during the unwinding of the yarn from the bobbin B, the diameter of the bobbin B decreases.

The movement of the support element 3 of the bobbin B ensures constant contact between the bobbin B and the drum 5.

In this respect, the feed device 1 also comprises movement means 18 acting on the support element 3 to translate it.

The movement means 18 comprise a slide 19 to which the support element 3 is connected. The slide 19 slides in a guide 23 provided in a containing body 20 rigidly associated with the main body 2.

Elastic means 21 are operatively disposed between the slide 19 and the main body 2 such as to exert on the support element 3 of the bobbin B a force directed towards the drum 5 to ensure constant contact between the bobbin B and the drum 5. In accordance with that illustrated, the elastic means 21 comprise a helical spring.

Advantageously, the device 1 also comprises a tension sensor 22 connected to the main body 2 downstream of the drum 5.

In detail, the tension sensor 22 is mounted on an arm 24 emerging from the main body 2.

The device 1 also comprises a control unit (not shown) operationally connected to the tension sensor 22.

In detail, the tension sensor 22 generates a tension signal representative of the value of the tension applied to the yarn unwinding from the bobbin B and feeds it to the control unit. Here, the tension signal is compared with a reference value which, for example, can be set by a user with reference to the type of yam and/or the required process. Based on this comparison, the control unit generates and feeds to the motor 6 a torque signal representative of the torque generated by the motor 6. More precisely, if the tension value is greater than the reference value, the toque signal is increased to increase the drum 5 velocity and hence the yarn delivery velocity, so decreasing its tension.

Vice versa, if the tension value is less than the reference value, the toque signal is decreased to decrease the drum 5 velocity and hence the yarn delivery velocity, so increasing its tension.

The invention conceived in this manner attains the proposed objects.

In this respect, the use of the support structure rigidly fixed to the drum interior enables the drum to provide the support necessary without the need for special support structures.

Hence, the drum length is not limited by these structural requirements and consequently the feed device can be used even with spools of different dimensions without particular limits.

Moreover, the support structure of the device according to the present invention enables even for spools of considerable weight to be effectively supported together with the force exerted by the spool support body, while always maintaining the motor shaft correctly aligned without particular space requirements, hence preserving motor functionality with time. Advantageously, in this respect the forces exerted on the support structure are not discharged onto the motor shaft nor onto the bearings, but directly onto the motor or onto the main body. Hence the limit value of the radial force applicable to the motor can be considerably increased, without this compromising the device operation over time.

Claims

1 . A device for feeding yarn to a textile machine, comprising a main body (2); a rotatable drum (5) having a lateral surface (5s) to rest against a yarn bobbin (B); a motor (6) connectable to said drum (5) and fixed to said main body (2); and a support structure (8) for said drum (5); characterised in that said support structure (8) is rigidly connected to said main body (2) and is disposed in the interior of said drum (5).

2. A device as claimed in claim 1 , characterised in that said support structure (8) is directly fixed to said motor (6).

3. A device as claimed in claim 2, characterised in that said support structure (8) comprises a sleeve (9) fixed to the motor (6) and disposed coaxially to an axis (M) of said motor and having a first end (9a) and a second end (9b), said sleeve (9) being associated with said first end (9a) and second end (9b) at a first end (5a) and a second end (5b) of said drum (5).

4. A device as claimed in claim 3, characterised in that said sleeve (9) comprises at its first end (9a) a coupling flange (10) facing said motor (6) to rigidly fix said support structure (8) to said motor (6).

5. A device as claimed in claim 3 or 4, characterised in that said support structure (8) comprises a transmission shaft (13) rotatably connected to the sleeve (9) and presenting a first end (13a) connected to the motor (6) and a second end (13b), opposite the first, fixed to the drum (5) at its second end (5b), to cause said drum (5) to rotate.

6. A device as claimed in claim 5, characterised by comprising a connection piece (14) disposed in the interior of said drum (5) and connected to said second end (13b) of the transmission shaft (13).

7. A device as claimed in claim 5 or 6, characterised in that said support structure (8) comprises a pair of bearings (15), each disposed between the sleeve (9) and the transmission shaft (13) at the first end (13a) and at the second end (13b) of the transmission shaft (13) respectively.

8. A device as claimed in claim 5, characterised in that said motor (6) comprises a motor shaft (7), said support structure (8) also comprising a flexible coupling for connecting together said motor shaft (7) and said transmission shaft (13).

9. A device as claimed in any one of the preceding claims, characterised by also comprising a support element (3) for housing said bobbin (B), said support element (3) being connected to said main body (2) and being disposed parallel to said drum (5).

10. A device as claimed in claim 9, characterised by comprising means (18) for moving the support element (3) in order to maintain said bobbin (B) in contact with said drum (5).

11. A device as claimed in any one of the preceding claims, characterised by also comprising a tension sensor (22) connected to the main body, (2) downstream of the drum (5) and a control unit; said tension sensor (22) being arranged to generate a signal representative of the exiting yarn tension measurement; said control unit receiving said tension signal and generating a corresponding torque signal representative of the torque delivered by said motor (6), to make said tension value uniform at a preferably programmable predetermined value, or to feed the yarn at constant velocity while continuing to monitor said tension value.