EP3298188B1

EP3298188B1 - Device for centring and widening a fabric in open-width form

Info

Publication number: EP3298188B1
Application number: EP16753460.1A
Authority: EP
Inventors: Massimo Biancalani; Riccardo Ravagli
Original assignee: Biancalani SRL
Current assignee: Biancalani SRL
Priority date: 2015-05-22
Filing date: 2016-05-23
Publication date: 2019-07-10
Anticipated expiration: 2036-05-23
Also published as: WO2016189454A1; ES2742517T3; EP3298188A1; CN107849772A; BR112017026694B1; BR112017026694A2; KR20180022675A; ITUB20150804A1; CN107849772B

Description

Technical field

This invention relates to a device for transversely centring and widening a fabric in open-width form fed along a longitudinal direction and without mechanical contact.

Prior art

In the technology of the textile industry, a fabric being fed lengthways very often, and for various purposes, needs to be widened and spread out crossways using automated methods.
To enable this to be done, mechanical devices are known which comprise helical widening rollers used to apply a widening action on the fabric.
These devices may also comprise centring systems, also mechanical, which are disjoined from the wideners and whose purpose is to compensate for misalignment and keep the fabric centred on the feed line by applying corrective movements to the fabric in response to displacements which the fabric may undergo as it moves forward.
EP1050500A2 discloses a centring/widening device adapted to widen and centre a fabric strip on a reference axis, the device consisting of two parallel tubes which are separated between them and face each other by a part of their wall for their entire length, both of said parts of wall being provided with nozzles (intended to blow, on the fabric advancing between them, the pressured air which is sent through said tubes by a fan.
DE19643524A1 discloses a device for moving a band of flexible material especially textile. It uses a blast of compressed air which enters terminal boxes which surround the edges of the strip of material. The compressed air is blown through nozzles which face back towards the edges of the strip of material. This ensures that the material is stretched laterally and crumpling and sagging in the middle is avoided. The air jets are angled so that the air issuing from them has an axial component so as to drag the strip along in its longitudinal direction.
Devices of this kind, although widely used in the sector, suffer from several disadvantages and functional limitations. In effect, some types of particularly delicate fabrics may be damaged by direct contact with mechanical parts which scrape the surface of the fabric or tangle its fibres. Another disadvantage is due to the fact that the operation of these mechanical devices requires keeping the fabric tensioned lengthways. As a result, certain types of fabric, such as knitted fabrics, for which lengthwise tensioning is highly inadvisable, may be treated with these mechanical devices with great difficulty and with relatively unsatisfactory results in terms of quality. Moreover, if the fabric also has to be subjected to thermal treatment - for example, drying or cooling - the above mentioned mechanical devices need to be integrated in other specific devices, creating working combinations which are complex in terms of plant engineering and which raise the overall cost of the production process.

Disclosure of the invention

This invention therefore has for an aim to overcome the above mentioned disadvantages by providing a device whose technical features are set out in the appended claims and whose advantages are more apparent from the following detailed description made with reference to the accompanying drawings which illustrate a non-limiting example embodiment of it.

Brief description of the drawings

In the drawings:

Figure 1 is a perspective assembly view of the device according to the invention represented in a schematic and partial form;
Figure 2 is a view of the device of Figure 1, cut along a horizontal plane in order to better illustrate some internal parts of it;
Figures 3a and 3b are perspective views, cut along a horizontal plane, of a variant embodiment of the invention of Figure 1 in two different operating conditions;
Figure 4 is a perspective assembly view of a more complex embodiment of the invention of Figure 1;
Figure 5 is a perspective horizontal cross section of the device of Figure 4;
Figures 6, 7a,7b, 8a, 8b are views of the device of Figure 4, with some parts cut away in order to better illustrate internal parts of it, according to specific operating states;
Figure 9 illustrates a system for treating a knitted fabric comprising the device of the invention.

Embodiments of the invention

With reference to the accompanying drawings, the numeral 1 in Figure 1 denotes a widening and centring device, without mechanical contact, for a portion 2 of fabric in open-width form fed along a longitudinal feed direction 3, preferably vertical.
The device 1 essentially comprises a horizontal structure 30, in the shape of a parallelepiped, having a rectangular through slot 23, which the portion 2 of fabric passes through as it moves continuously along the vertical, longitudinal direction 3 under a suitable feeding action applied to the portion 2 by respective feed means not illustrated. In Figure 2, it may be noted that the device 1 comprises two grooves 24 which are associated with the slot 23 and which are oriented in a horizontal direction 8, transversal to the portion 2 of fabric.
More specifically, the grooves 24 are located bilaterally to the portion 2 of fabric and the open sides of their contours are directed towards the opposite faces 2a and 2b of the portion 2.
Substantially half way along the slot 23, the device 1 comprises two ducts 5 connected to the grooves 24 to supply the grooves 24 with a pressurized air flow 4.
As shown in Figure 2, the ducts 5 blow into the grooves 24 gaseous flows 4 of pressurized air which travel the grooves 24 from the centre towards the periphery of the portion 2 of fabric tangentially along the portion 2 itself in the transversal direction 8. The structure 30 of the device 1 also comprises directing means for selectively directing into each groove 24 the gaseous flow 4 delivered by the respective supply duct 5.
From Figure 2, it may be noted that the directing means comprise a small diverter plate 6 housed in the groove 24 facing the respective supply duct 5. The plate 6, when struck by the total flow 4 from the duct 5, divides the flow into two oppositely directed flows 4d and 4s directed away from the central zone of the portion 2 of fabric and flowing in the grooves 24 tangentially to the portion 2 and progressively towards the lateral edges 2t thereof.
Since the flows 4 operate in opposition to each other, the portion 2 of fabric is subjected to a strong tangential pulling action which causes it to spread out in its transversal direction 8 and keeps it in that condition. If the opposite flows 4d and 4s were not identical, that is, such as to balance each other, the portion 2 of fabric would, in its entirety, be subjected to translation in the transversal direction 8, which would cause it to be displaced sideways, resulting in its misalignment relative to the middle of the slot 23.
The air which supplies the gaseous flow 4 thus operates on the fabric like a totally fluid widening and centring actuator without direct contact with rigid parts.
Moreover, the air can advantageously be heated or cooled to be used as fabric drying or cooling means. Such drying means might therefore be integrated or able to be integrated at a very low cost into the fluid actuator to meet other technological requirements related to fabric processing.
Furthermore, the supply flow rate might be made variable in order to adjust the intensity of the actions applied to the fabric.
Figures 3a and 3b show a variant embodiment of the device of Figure 2, where the directing means include shutoff means 7 - preferably embodied in this specific case by swing flap valves - interposed between the fixed diverter plate 6 inside the grooves 24 and the end part of the supply ducts 5.
By suitably adjusting the orientation of the flap valves it is possible to modulate the flows 4 more or totally towards one or the other of the edges 2t of the portion 2 of fabric so as to cause the portion 2 in its entirety to move decidedly one way or the other along the transversal direction 8, as may be clearly observed by comparing Figures 3a and 3b. Figure 4 shows another version of the device according to the invention, denoted in this case by the numeral 9, which allows both widening and centring - if necessary with large displacements - of the portion 2 of fabric as it moves through the slot 23 continuously. In this drawing, as in the other drawings accompanying this specification, the portion 2 of fabric is considered as moving from the bottom up. This feature is totally exemplary and non-limiting, it being understood that the device 1 is perfectly reversible and can operate just as well with the fabric moving in the exact opposite direction.
Figure 4 also shows the air flows 4 which supply the device 9 and those which travel along the grooves 24 towards the outside in such a way as to act on the fabric.
In Figure 5 it may be noted that in the embodiment of the device 9 described here, the directing means comprise, in addition to the two small middle plates 6, four further small diverter plates 16 which are located at the sides of the slot 23 and which are designed to divert in a direction transversal to the portion 2 of fabric the air supplied into the device 9.
The directing means also comprise two spool valves 17 and 20 located half way along the slot 23 and driven by pairs of pneumatic mini cylinders 10 and 13, respectively. The spool valves 17 and 20 can adopt three different positions, starting from the neutral middle position and allowing the air to be selectively diverted towards the right-hand end of the slot 23, that is, towards the right-hand side of the portion 2 of fabric, or towards the left-hand end.
The directing means also comprise two further spool valves 18 and 19 located at the right-hand end of the slot 23 and driven by pneumatic minicylinders 11 and 12; and two further spool valves 21 and 22 located at the left-hand end of the slot 23 and driven by pneumatic minicylinders 14 and 15.
The spool valves 18,19,21 and 22 can adopt two positions, open or closed, and allow or prevent air from being fed in against one or the other edge 2t of the portion 2 of fabric. This action makes it possible to implement pushing actuators acting on the edge 2t of the portion 2 and designed to push it, if necessary, in the transversal direction 8 and to locally reinforce the main action produced by the state of the middle spool valves 17 and 20. This is particularly useful (as will be better understood below) when the portion 2 of fabric is greatly displaced to one side or the other relative to the middle of the slot 23.
Figures 6 to 8b well clarify the technical concepts set out above.
From Figure 6, looking at the paths of the air flows 4 indicated by the arrows, it may be inferred that in the condition where the end spool valves 18,19,21,22 are closed and the middle spool valves 17,20 are in the middle position, the device 9 applies a powerful pulling action on the fabric both ways along the transversal direction 8, thereby imparting a strong widening action and a moderate centring action on the portion 2 of the fabric relative to the middle of the slot 23.
In Figure 7a, the end spool valves 18,19,21,22 are closed and the middle spool valves 17,20 are in the position where they supply air towards the right. In this condition, the device 9 applies a strong transversal pulling action on the fabric, causing the portion 2 in its entirety to be greatly displaced towards the right.
Figure 7b shows the same condition but where the portion 2 of fabric undergoes a strong displacing action towards the left.
In Figure 8a, the end spool valves 21,22 on the left of the slot 23 are open, while those on the right 18,19 are closed. The middle spool valves 17,20 are in the position where air is directed towards the right. In this condition, the device 9 applies a very strong displacing action towards the right to return the portion 2 to the centre even if it is all to the left of the slot 23.
In Figure 8b, the situation is reversed, that is to say: the end spool valves 18,19 on the right are open, while those on the left 21 and 22 are closed. The middle spool valves 17,20 are in the position where the air flow 4 is directed towards the left. In this case, the device 9 applies a very strong displacing action towards the left even if the portion 2 is initially all to the right of the slot 23.
The device according to the invention fully achieves the aims of widening and centring a portion 2 of fabric on the feed line and, moreover, offers further major advantages.
In effect, since the fabric does not come into contact with mechanical parts, or in any case, with any rigid parts, the faces 2a and 2b of the fabric are not subjected to any scraping action. Compared to the prior art, this is an improvement over traditional fabric treatment technology and makes it possible to increase the range of fabric types that can be successfully treated with the device.
The fabric is practically not stretched lengthways at all but the portion 2 of fabric is subjected to a pulling action only in the transversal direction 8, which means that a wide variety of fabrics, including knitted fabrics, can advantageously be treated without any limitations.
Fabric centring relative to the feed line can be controlled very effectively at all times, even when the fabric is totally off centre. This, on the contrary, constitutes a major limitation in prior art devices.
Additional thermal treatments of the fabric can be easily and economically integrated in the device by heating and cooling the very same air which is used for the primary purposes of widening the centring the fabric.
The totally reversible operation of the device on the feed line is decidedly more advantageous than traditional mechanical devices which operate in one direction only. The spool and/or flap valves used to control the transversal position of the fabric can advantageously be controlled automatically by a control system driven by electronic sensors which detect the position of the two edges of the fabric.
Figure 9 illustrates a system for treating a knitted fabric M, comprising two or more vibratory tanks (three tanks 90,91,92 in the example illustrated) placed one after the other. The fabric M is fed/picked up from each tank by means of widening/centring devices 93 having the features set out above and positioned at the infeed of the first tank 90, at the outfeed of the last tank 92 and between each pair of successive tanks (90,91 and 91,92 in the example). Advantageously, further widening/centring devices 94 can be located substantially in the middle of one or more tanks 90,91 to pick up the fabric from the tank and release it into the same tank.

Claims

A device for centring and widening a portion (2) of a fabric in open-width form fed along a longitudinal feed direction (3), comprising a structure (30) having a slot (23), which the portion (2) of fabric passes through as it moves continuously along the longitudinal direction (3), characterized in that
- at least one groove (24) is associated with the slot (23), oriented in a direction (8) transversal to the portion (2) of fabric and directing towards the portion (2) of fabric an open side of its contour;

- at least one supply duct (5) is associated to said at least one groove (24) for delivering at least one gaseous flow (4;4d,4s) travelling along it tangentially to the portion (2) of fabric in the transversal direction (8);

- directing means are provided for selectively directing into said at least one groove (24) the gaseous flow (4;4d,4s) delivered by said at least one supply duct (5);
whereby said at least one gaseous flow (4;4d,4s) applies on the portion (2) of fabric a corresponding action which causes it to be widened and/or centred relative to the slot (23).
The device according to claim 1, characterized in that the structure (30) includes two grooves (24) located bilaterally to the portion (2) of fabric and having the open sides of their contours directed towards the opposite faces (2a,2b) of the portion (2).
The device according to claim 1 or 2, characterized in that the at least one gaseous flow (4;4d,4s) starts flowing from a substantially central area of the portion (2) and proceeds towards a lateral edge (2t) of the portion (2) itself.
The device according to any one of the preceding claims, characterized in that said at least one supply duct (5) is associated with the groove (24) substantially half way along the slot (23).
The device according to any one of the preceding claims, characterized in that the directing means include a diverter plate (6) housed in the groove (24) facing the supply duct (5) and which divides the total flow (4) from the supply duct (5) into two oppositely directed flows (4d,4s) tangential to the portion (2) of fabric.
The device according to claim 5, characterized in that the directing means include switchable shutoff means (7) which are interposed between the diverter plate (6) and the supply duct (5) and which are adjustable to direct the gaseous flow (4) selectively towards one or the other of the edges (2t) of the portion (2).
The device according to claim 5, characterized in that the directing means include at least one three-position valve (17,20) combined with the diverter plate (6) and driven to selectively divert the air flow (4) along the groove (24) and towards opposite ends of the slot (23).
The device according to claim 7, characterized in that it comprises actuators for pushing the edge (2t) of the portion (2) of fabric in the transversal direction (8), located at the ends of the slot (23), and able to be driven in combination with the or each three-position valve (17,20).
The device according to claim 8, characterized in that the actuators for pushing the fabric in the transversal direction (8) comprise two-position valves (18,19,21,22) associated with the opposite ends of the slot (23) through which the portion (2) of fabric passes.
The device according to any one of the preceding claims, characterized by being supplied with hot or cold air to dry or cool the fabric.