TORCOLI, Roberto (Via Cologna, 38 Sulzano, Brescia, I-25058, IT)
PRANDINI, Girolamo (Via Fiume Oglio, 58 Rocca Franca, Brescia, I-25030, IT)
TORCOLI, Roberto (Via Cologna, 38 Sulzano, Brescia, I-25058, IT)
1. Lap (L) -forming device (1) for a fibre processing machine, such as a lap-winder,
said device being able to pass from an initial lap- forming configuration to a final lap-forming configuration,
said device comprising:
- a formation area (20) wherein the lap is positioned from the initial configuration to the final configuration;
- a primary calender (22) suitable for rotating to form the lap around a rotation axis,
a secondary calender (24) adjacent to the primary calender, suitable for rotating to form the lap around its own rotation axis, said calenders being suitable for supporting the lap being formed from the initial configuration to the final formation configuration
a belt (30), partially wound around the primary calender (22) , which forms a circuit near the formation area (20), in contact with the lap being formed from the initial configuration to the final formation configuration
wherein the belt (30) is multi-layer.
2. Device according to claim 1, wherein the belt comprises a processing layer (30a) having an outer surface (30a') destined to come into contact with the lap, made from polyurethane .
3. Device according to claim 1 or 2, wherein the belt comprises an intermediate reinforcement layer (30b) made from polyester fabric.
4. Device according to any of the previous claims, wherein the belt comprises a dragging layer (30c) destined to come into contact with the primary calender (22) , made in polyester.
5. Device according to any of the previous claims, wherein the belt (30) is perforated in its thickness.
6. Device according to claim 5, wherein the holes (30d) are arranged in staggered parallel rows.
7. Device according to claim 5 or 6, wherein the holes occupy 0.5% to 20% of the surface area of the belt, preferably 0.8% to 10%.
8. Device according to any of the previous claims, wherein the rims are sealed using the same material as the processing layer (30a) .
9. Device according to any of the previous claims, wherein the longitudinal rigidity (Kl%) is 10 to 30 N/mm, preferably equal to 20 N/mm.
10. Device according to any of the previous claims, wherein the transversal rigidity (Kl%) is 2 to 10 N/mm, preferably equal to 5 N/mm.
LAP FORMING DEVICE WITH A BELT
 The present invention relates to a lap-forming device with a belt, for machines processing fibre slivers, such as a lap-winder.
 A fibre processing line entails processing a fibre, usually starting from fibre in tufts, to obtain a yarn.
 The system is composed of numerous machines; in particular the carding machines make it possible to obtain fibre slivers.
 In a lap-winder, positioned downline of the carding machines, a plurality of slivers are drawn and combined to form a web, wound on a tube to form a lap in a lap- forming device.
 One example of embodiment of a lap-forming device with a belt is described in the Italian patent application for an invention BS2008A000232, in the Applicant's name. Further examples are described in EP160165 and US3134553.
 The structural characteristics of the belt are particularly important for the correct functioning of the device .
 The aim of the present invention is to make a lap- forming device with a belt which ensures particularly high performance of the device.  Such purpose is achieved by a lap-forming device made according to claim 1.
 The characteristics and advantages of the lap- forming device according to the present invention will be evident from the description below, offered by way of a non-limiting example, with reference to the appended figures, in which:
 - figure 1 shows a perspective view of a lap-forming device with a belt;
 - figure 2 shows a scheme of a belt of the device in figure 1;
 - figure 3 shows a cross-section of the belt in figure 2; and
 - figure 4 shows the belt according to a further embodiment.
 According to the invention, a machine for processing fibre slivers or a web, such as a lap-winder, comprises a lap-forming device 1.
 The device 1 has an entrance area 2 for the entrance of a web W, coming from machinery upline of the device 1, for example from drawing and winding equipment of the lap-winder.
 Preferably, the device 1 comprises an entrance unit 4 for receiving the incoming web W and deviation of the direction of advancement, positioned in the entrance area 2.
 For example, the entrance unit 4 comprises a motorised entrance cylinder 6, and a pair of entrance cylinders 8, 10 engaged with the entrance cylinder 6 to drag the web.
 Preferably, moreover, the input device 4 comprises an alignment cylinder 12.
 The device 1 further comprises a pair of calenders, of which at least one is motorised, preferably with a fixed rotation axis, to form the lap L. In particular, the lap L is formed in a formation area 20 between said calenders .
 Furthermore, the device 1 comprises at least one belt 30 engaged with at least one of said calenders, denominated the primary calender 22, facing the other calender, denominated the secondary calender 24, to accompany the formation of the lap L.
 In particular, the belt 30 is in contact with the primary calender 22 at least in a contact portion, moving in a sector of a circle, positioned opposite the formation area 20, that is opposite the secondary calender 24.
 Preferably, the calenders have different diameters and in particular the primary calender has a smaller diameter than the secondary calendar. For example, the ratio of the diameter of the primary calender to the diameter of the secondary calender is 0.1 to 0.4, preferably 0.2 to 0. 3 , preferably equal to 0.27.
 Preferably, moreover, the device 1 comprises means of adjusting the tension able to regulate the tension of the belt 30 during formation of the lap.
 For example, the tension regulator devices comprise a tightening roller 40 engaged with the belt 30, having a mobile rotation axis, to pull or release the belt and thereby adjust the tension.
 According to a preferred embodiment, the belt 30 forms a closed circuit which surrounds the primary calender 22. For example, the alignment roller 12 and the tightening roller 40 are positioned inside the circuit formed by the belt.
 The belt 30 forms a means of transport of the lap for at least a part of the circuit.
 The device 1 further comprises guide means for guiding the lap being formed or the tube.
 For example, said guide means comprise a carriage comprising a pair of plates 52, positioned distanced along the rotation axis of the calenders 22, 24 so as to delimit an area between them.
 The tube T, with no lap yet wound around it, is positioned in the formation area 20 between the plates 52 of the guide means when formation of the lap commences.
 The carriage further comprises first means of movement, connected to the plates 52, to move these in a formation direction. For example, said means of movement are pneumatic.
 According to one embodiment the device 1 comprises means of containment of the belt, comprising for example a pair of flanges 200, each coupled on one side of the primary calender, projecting radially from the surface of it. In said embodiment, the belt is a little narrower than the axial dimension of the primary calender, remaining contained between the flanges.
 According to a further embodiment the belt has a greater width than the axial dimension of the primary calender, so as to project from the rims of it, but slightly less than the axial distance between the plates 52.
 Advantageously, this way the problem of the fibre being caught between the edge of the belt and the plates 52 is limited.
 The belt 30, according to a preferred embodiment, is of the multilayer type, that is to say, formed of a number of overlapping layers.
 Preferably, the belt 1 comprises a processing layer 30a, the outer surface 30a'of which is destined to come into contact with the web W, made from polyurethane, and is smooth and non-adhesive.
 Furthermore, the belt 30 comprises an intermediate reinforcement layer 30b, for example made from polyester, positioned on the inner surface of the processing layer 30a.
 Furthermore, the belt 30 comprises a dragging layer 30c, positioned in contact with the reinforcement layer 30b and destined to come into contact with the pulleys moving the belt, made from polyester fabric.
 Preferably, the belt 30 has a longitudinal modulus of elasticity, that is to say in the direction of advancement of the belt, of 10 to 30 N/mm, preferably equal to 20N/mm, and a transversal modulus of elasticity, that is in the direction orthogonal to that of advancement of the belt, of 2 to lON/mm, preferably equal to 5N/mm.
 The moduli of elasticity indicated above are generally indicated as Kl% and show the traction load needed to achieve a 1% increase in length per unit of width (1mm); the sample is extracted in length in the direction in which one wishes to measure the Kl%.
 Preferably, moreover, the belt according to the present invention has a width of 270 to 310 millimetres, in general 285 or 299 millimetres, with a tolerance of ±0.5 millimetres.
 Preferably, moreover, the belt has a planarity on its sides of 0.10 to 0.30 millimetres.
 Preferably, moreover, the belt 30 has sealed rims (figure 3) .
 The rims are sealed by removing from along the rims an area of limited width, generally 10-15 millimetres, of the reinforcement layer 30b and of the dragging layer 30c, while leaving intact the processing layer 30a. The excess material of the processing layer 30a is melted so as to close the sides of the reinforcement and processing layers, which are thereby sealed. Lastly, the rim obtained is trimmed to the desired size.
 Consequently, the sealed rim of the belt 30 is made completely from processing layer material 30a and the reinforcement and dragging layers are contained within the rims, thereby not surfacing on the sides (figure 3).
 Preferably, moreover, the belt 30 is perforated through its thickness, by means of a plurality of holes 30d, for example so that the percentage of open surface area varies from 0,5% to 20% of the surface area, preferably 0,8% to 10%.
 According to a preferred embodiment the holes are arranged in a succession of parallel rows in the direction of advancement of the belt 30, for example in rows orthogonal to the direction of advancement.
 Preferably, the holes 30d of one row are staggered in relation to the holes of the previous row; in other words, a hole on the next row is positioned between two holes of the previous row considering the direction of advancement of the belt .
 Advantageously, the holes in the belt make it possible to evacuate the air currents generated in the formation area of the lap.
 According to a preferred embodiment two subsequent rows of holes are 20 millimetres away from each other in the direction of advancement of the belt; two holes on the same row are 20 millimetres away from each other transversally and the holes of the subsequent row are positioned midway between the holes of the previous row. Preferably, the holes have diameter of 3 millimetres.
 Preferably, the holes are made using a punch, which enters the thickness of the belt from the side of the contact surface 30a' , so that any burrs do not come out on said surface.
 Innovatively, the formation device with belt according to the present invention makes it possible to considerably improve the performance of the machine.
 Advantageously, the belt of the device has rigidity values such as to permit formation of the lap at high speeds, limiting the formation of matting.
 According to a further advantageous aspect, the belt make it possible to evacuate the air currents generated in the formation area during the formation cycle.
 Advantageously, moreover, the belt does not have the tendency to remain stuck to the lap on its surface.
 According to a further advantageous aspect, the sides of the belt do not capture the fibres of the lap being formed and do not accumulate them.
 It is clear that a person skilled in the art may make modifications to the lap-forming device with a belt described above, all contained within the sphere of protection as defined by the following claims.