FIBERS FEEDING DEVICE FOR FEEDING TUFT TO A WORKING MACHINE, LIKE A CARDING MACHINE

[0001] The present invention relates to a fibre feed device of a working machine, for example for feeding fibre in tufts to a carding machine.

[0002] A fibre processing line for the production of yarn is composed of several working machines for example, one or more carding machines and some devices in which the fibre, for example in tufts, is accumulated before being fed to the working machines. The working machines and the feed devices are connected to each other by conveyor ducts, in which the fibre is transported by currents of air .

[0003] Despite the essential work being carried out by the working machine, the functionality of the feed device is extremely important: it has, in fact, been ascertained that the way in which the fibre is fed to the working machine considerably influences the results of processing by the said working machine.

[0004] Numerous fibre feed device solutions for spinning lines are known of; for example, some embodiments are shown in documents EP-A1-458818 , EP-A1-468985 or are known of, such as the feed device B136 in the name of the Applicant.

[0005] It is essential that the fibre stored in a silo of the feed device is fed to the working machine gradually and regularly, without being subjected to vortical movements tangling it; at the same time however the need for increasingly high processing flows ensuring greater productivity must also be safeguarded.

[0006] The purpose of the present invention is to satisfy the aforesaid requirements. Such purpose is achieved by a feed device according to claim 1 below. The dependent claims describe embodiment variations.

[0007] The characteristics and advantages of the feed device according to the present invention will be evident from the following description, made by way of a non- limiting example, wherein:

[0008] - figure 1 shows a section of a spinning line comprising feed devices according to the present invention;

[0009] - figure 2 shows a cross-section of the feed device according to the present invention;

[0010] - figure 3 shows an enlargement of the box III in figure 2; [0011] - figure 4 shows an axonometric view of a portion of the feed device, with particular focus on the recovery of the conveying current of air;

[0012] - figure 5 shows an axonometric view of a box forming a suction compartment of the device according to an axonometric view of a box

forming a suction compartment of the device according to the invention, according to a further embodiment; and

[0014] - figure shows the box in figure yf, without the cover .

[0015] With reference to the attached figures, reference numeral 1 globally denotes a section of a spinning line.

[0016] The spinning line comprises a plurality of working machines, such as a plurality of carding machines 2, and a distribution duct 4 in which the fibre is transported in a current of distribution air. Moreover, the line 1 comprises at least one feed device 6 which the fibre reaches in a current of air, inasmuch as connected to the conveyor duct 4. The device 6 is positioned upstream of the respective working machine, to which it feeds the fibre.

[0017] The feed device 6 comprises a silo 8 having a main extension along a silo axis Y between an upper feed aperture connected to the conveyor duct 4 and a lower aperture positioned at a lower height than that of the upper portion.

[0018] In a preferred form of embodiment, the silo axis is vertical, that is orthogonal to the ground plane which the device rests on; in a further embodiment the silo axis is inclined in relation to the ground plane.

[0019] The silo 8 comprises at least one upper air- permeable wall 10 suitable for being traversed by the current of air.

[0020] Outside the silo 8, beyond the permeable wall 10, the device 6 comprises a first recovery compartment 12 for transit of the conveying current of air which has come through the permeable wall.

[0021] Downstream of the silo 8, the feed device 6 comprises a feed roller 14, faced on the surface, rotating around a feed axis 16 transversal to the silo axis Y, in a feed direction of rotation 14a.

[0022] At the lower extremity of the silo 8, but upstream of the feed roller 14, the device 6 comprises a guide wall 18, preferably flat, for example inclined so as to reduce the cross-section of transit of the fibre, terminating in a guide rim 20. The feed direction of rotation is away from the rim 20 of the guide wall 18.

[0023] Opposite the guide wall 18, the device 6 comprises a feed basin 22, delimited by one at least partially curved wall, concave towards the inside of the silo, ending in a basin rim 24. The feed direction of rotation is towards the basin 22.

[0024] The lower aperture of the silo 8 is defined between the guide rim 20 and the opposite basin, for example on a plane containing the guide rim 20 and perpendicular to a vertical axis.

[0025] According to a preferred embodiment, the guide rim 20 of the wall 18 vertically overlaps the feed axis of the roller 14 so that the lower aperture of the silo opens onto a portion 26 of the lateral surface of the feed roller which, when the roller is rotating, rotates downwards .

[0026] In a further embodiment, the guide rim 20 of the wall 18 is offset with the feed axis 16 in the feed direction of rotation 14a.

[0027] Moreover, a portion of the lateral surface of the feed roller 14 forms a channel with the basin 22 having a decreasing cross-section in the advancement direction of the fibre.

[0028] According to a preferred embodiment, the basin rim 24 of the basin 22 is below the feed rotation axis 16, that is below a horizontal plane passing through said axis 16.

[0029] In a further embodiment variation, the basin rim 24 of the basin 22 is level with the feed axis of the roller 14, (that is they lie on the same horizontal plane).

[0030] Moreover, the feed device 6 comprises an opening roller 30, downstream of the feed roller 14, with tips on the surface, rotating around an opening axis 32 in an opening direction of rotation 30a, opposite the feed direction of rotation 14a.

[0031] The feed roller 14 and the opening roller 30 interact in an area of the lateral surface downstream of the basin rim 24, to pass the fibre from the feed roller to the opening roller; the peripheral speed of the opening roller is greater than the peripheral speed of the feed roller.

[0032] A plane inclined in relation to the ground plane passes through the feed axis 16 and the opening axis 32.

Preferably, the inclination is 48° to 52°, preferably

49.5 ° to 50.5 °, preferably 50°. [0033] A plane T tangent to the surface of the feed roller and the opening roller having been identified, bearing in mind the circumference defined by the tips or facing on the surface, on the side of the basin 22, the compartment defined between said tangent plane, the two lateral surfaces of the rollers 14,30 and the area of interaction in which said rollers exchange the fibre (figure 3) is defined as the "gap" 34 between the rollers.

[0034] The basin 22 is such as to extend in the gap 34 between the rollers 14, 30. Preferably, the basin rim 24 is downstream of the opening axis in relation to the opening direction of rotation.

[0035] According to one embodiment variation, the basin rim is aligned vertically with the opening axis 32.

[0036] The feed device 6 further comprises blowing means able to blow a conveying current of air.

[0037] For example, the blowing means comprise a motor 40 and a fan 42 able to suck air from a suction compartment 44 and to blow the conveying current of air into a blowing duct 50 which opens against the opening roller 30, preferably beside the basin 22.

[0038] The aperture of the blowing duct towards the opening roller is such that the outgoing current of conveying air is in the same direction as the rotation of the opening roller, in the area where said current and said roller are incident.

[0039] Preferably, the output direction of the current of conveying air from the blowing duct 50 is tangent to the opening roller 30.

[0040] Preferably, moreover, the blowing duct 50 emerges upstream of the area of interaction of the rollers 14,30.

[0041] The current of conveying air facilitates the detachment of the fibre from the opening roller 30 and transports the fibre downstream in a. current of air.

[0042] The device 6 further comprises an output wall 60, positioned downstream of the interaction area of the rollers 14,30, delimited preferably by a curved wall, concave towards the opening roller 30, which forms with the lateral surface of the opening roller 30 a divergent channel .

[0043] Downstream of the opening roller 30, the device 6 comprises an end compartment 70, preferably inclined, which the fibre accumulates in.

[0044] The end compartment 70 is delimited by at least one upper air-permeable wall 72 suitable for being traversed at least partially by the current of air. [0045] Outside the compartment 70, beyond the permeable wall 72, the device 6 comprises an intermediate compartment 74 for the transit of the current of conveying air which has come through the permeable wall 72.

[0046] The current of conveying air brings the fibre towards the end compartment 70, compresses it and flows out of the end compartment through the permeable wall 72.

[0047] The intermediate compartment 74 is delimited by a partition 76 responsive to the current of air so as to regulate the width of an exit gap 78 towards a second recovery compartment 80 in proportion to the current of air .

[0048] In particular, with the machine stationary, the partition 76 is substantially parallel to the permeable wall 72.

[0049] According to a preferred embodiment, the partition 76 is fixed and deformable.

[0050] According to further embodiments, the partition has a continuous surface or the partition has a perforated surface .

[0051] The second recovery compartment 80 is fluidically connected to the suction compartment 44 of the fan 42. [0052] In particular, the recovery compartment 80 is delimited at the top by an upper wall 82, attached for example above the partition 76, to which at least one air suction vent present in the recovery compartment 80 is connected.

[0053] Preferably, at least two vents 84a, 84b are provided which fluidically connect the recovery compartment 80 to the suction compartment 44 of the fan 42.

[0054] Preferably, moreover, the two vents 84a, 84b are positioned symmetrically (for example in relation to a plane of symmetry perpendicular to the rotation axes of the rollers) on the upper wall 82 and, at least in an initial section connected to the upper wall 82 and are L- shaped, so as to channel the outgoing flows of air in an opposite direction to each other

[0055] According to a preferred embodiment, the suction compartment 44 is delimited by a box 200 fitted with two inlets 202a, 202b, which are respectively connected fluidically to the two vents 84a, 84b, of the recovery compartment 80, and an outlet 204 which the fan 42 faces.

[0056] In particular, the outlet 204 defines a suction axis J, for example coinciding with the rotation axis of the fan blades 42. The inlets 202a, 202b rather, have tangential axes W, lying on a plane perpendicular to the suction axis J.

[0057] Preferably, the box 200 has a spiral-shaped inner compartment 206, which the two inlets 202a, 202b open into, fitted in a central position with a separation boss 208 having the shape of a rotary solid with a lateral surface converging towards the outlet 204.

[0058] This way, the two air flows coming in through the inlets 202a, 202b do not disturb each other in that they are mixed during the rotatory movement around the boss 208, by which they are divided at the intake, and are guided towards the outlet 204.

[0059] According to a further embodiment, the inlets 202a, 202b of the box 200 are coaxial (figures 6 and 7), that is positioned along the same tangential axis W.

[0060] Said box 200 is further provided with an outlet 204 which the fan 42 faces; the outlet 204 defines a suction axis J, for example coinciding with the rotation axis of the fan blades 42. The tangential axis W lies on a plane perpendicular to the suction axis J.

[0061] The one inner compartment 206 of the box 200 is delimited, on one side by a divisor wall 210 formed of two arched sections 212 which meet in a vertex 214, forming an arched "V"; each arched section 212v is positioned opposite a respective inlet 202a, 202b so as to channel the flow of air coming out of the respective inlet 202a, 202b towards the outlet 204, preventing them from being incident to each other and thereby causing reciprocal disturbance.

[0062] Furthermore, on the remaining side, the inner compartment 206 is delimited by a closure wall 216 which surrounds the outlet 204, in the shape of an overturned "U".

[0063] The end compartment 70 is also delimited for example on the upper part, by a mobile wall 90, for example hinged below the opening roller 30.

[0064] Downstream of the end compartment 70, the device 6 comprises a pair of counter-rotating extraction rollers 100,1110, positioned so as to close off said compartment 70. The rotation of the rollers 100,110 permits extraction of the fibre from the end compartment and starting of the working machine.

[0065] Innovatively, the feed device according to the present invention enables the machine to be fed gradually and regularly, even in the presence of materials highly permeable to air and therefore difficult to compress. [0066] Advantageously, all the fibre coming out of the silo is propelled downstream by the feed roller, without any effects against the direction of advancement of the fibre (due to the surface of the rotating roller and the current of air generated by it) .

[0067] According to a further advantageous aspect, the basin accompanies the fibre as far as the interaction area between the feed and opening rollers, where both rollers propel the fibre downstream, in this case too without effects against the direction of advancement of the fibre (due to the surface of the opening roller in rotation and to the currents of air generated by the two rollers) .

[0068] According to a further advantageous aspect, the current of conveying air coming out of the blowing duct does not disturb the passage of the fibre from the feed roller to the opening roller.

[0069] According to a further advantageous aspect, the thick fibres in the end compartment are not disturbed by the conveying current coming out through the lower permeable wall thanks to the gradual adjustment effect performed by the deformable partition.

[0070] It is clear that a person skilled in the art may make modifications to the device described above in order to satisfy specific requirements while remaining within the sphere of protection as defined by the following claims.