CN114514108B

CN114514108B - Feeding device and method for feeding a continuous elongated element

Info

Publication number: CN114514108B
Application number: CN202080069596.4A
Authority: CN
Inventors: A·蒙泰罗索
Original assignee: Pirelli Tyre SpA
Current assignee: Pirelli Tyre SpA
Priority date: 2019-10-16
Filing date: 2020-10-08
Publication date: 2023-10-31
Anticipated expiration: 2040-10-08
Also published as: EP4045275A1; CN114514108A; WO2021074940A1

Abstract

A feeding device (999) and a method for feeding a continuous elongated element (900), wherein the continuous elongated element is clamped between a first roller (1) and a second roller (2) arranged side by means of a push actuator (5), the first roller and the second roller having respective axes of rotation (101, 102) substantially parallel to each other, wherein the first roller (1) and the second roller (2) are rotated by a motor (8) and a transmission (14) for advancing the continuous elongated element for feeding the continuous elongated element to a feeding point (a) at a feeding speed, wherein the respective rotational speeds of the first roller (1) and the second roller (2) are controlled by the motor (8) and the transmission (14) for limiting or preventing a change in the respective rotational speed due to an effect of the continuous elongated element (900) exerted on at least one of the first roller (1) and the second roller (2).

Description

Feeding device and method for feeding a continuous elongated element

Technical Field

The present invention relates to a feeding device and a method for feeding a continuous elongated element, in particular for producing tyres.

Background

In the context of tire manufacturing processes, it is common to process or manipulate continuous elongated elements (e.g., ribbon-like elements) that are typically entirely elastomeric compounds or contain elastomeric compounds in combination with other elements.

The term "feeding" and the like refer to transporting a continuous elongated element through a feed point for any type of processing (e.g., mixing, extruding, cutting, unwinding or winding, coupling with other elements, calendaring, etc.).

"continuous elongated element" refers to a structurally bonded element having a longitudinal dimension (defining a length) that is substantially greater than the remaining dimension (defining a width and thickness) and having a cross-section perpendicular to the longitudinal dimension of any shape (e.g., rectangular, circular, oval, irregular, etc.).

For example, it is known to feed a continuous elongated element to a continuous processing machine to continuously process a material. Feeding the continuous elongated element to the machine may or may not be performed in combination with feeding of other components.

For the purposes of the present description and/or of the following claims, the expression "continuous processing machine" means a machine to which the material to be processed (for example, the composition of the continuous elongated element and/or of the compound) is fed continuously (except possibly for the machine being stopped due to maintenance or to a variation of the formulation of the desired product) so as to obtain the desired product, and from which the product is discharged by a substantially continuous flow.

Continuous processing machines include continuous mixers for producing a compound (e.g., a masterbatch, an intermediate, or a final compound), such as a two-screw mixer (i.e., twin screws, typically co-rotating), an annular extruder (i.e., having a plurality of co-rotating screws arranged in an annular array), a planetary extruder (i.e., a mixer having a rotating central mandrel and a plurality of planetary mandrels arranged about and engaged with the central mandrel to rotate about the central mandrel and to itself rotate with the rotation of the central mandrel). These mixers enable high-energy mixing of the materials introduced therewith, both in the state of independent components (separated or combined) and in the state of compounding (even cold), the active elements of the mixer (for example screws and/or spindles) being characterized by the fact that they comprise, extending along their longitudinal direction, a conveying portion (for example a helical thread) for advancing the materials, interspersed with mixing portions (for example compression and shear plasticating elements).

Continuous processing machines also include extruders for producing semifinished products (e.g. tread bands, beads, etc.) for use in tyre production, such as single-screw and twin-screw extruders (typically counter-rotating), extruders for semifinished products (e.g. profilers), feed extruders for textile rubberizing calenders. These extruders, although inevitably giving low mixing, mainly perform the function of pushing the compound towards the outlet mouth. These extruders do not generally be able to produce composites starting from individual components.

The continuous elongated element may be fed directly to a feeding portion of the continuous processing machine, wherein the feeding portion generally comprises a feed screw (at least one) that captures the continuous elongated element and drags it to a mixing and/or conveying chamber of the processing machine. Typically, the continuous elongated element is simply fed by gravity only to the feed screw of the machine described above, for example by a hopper.

By "substantially perpendicular" with respect to geometric elements (e.g., lines, planes, surfaces, etc.) is meant that these elements (or elements parallel thereto and incident upon each other) form an angle, inclusive, of between 90 ° -15 ° and 90 ° +15°, preferably between 90 ° -10 ° and 90 ° +10°.

By "substantially parallel" with respect to the above-mentioned geometric elements is meant that these elements (or elements parallel thereto and incident upon each other) form an angle comprised between 0 ° -15 ° and 0 ° +15°, preferably between 0 ° -10 ° and 0 ° +10°, inclusive.

The terms "optical," "light," and the like refer to electromagnetic radiation that does not necessarily fall strictly within the optical band (i.e., 400-700nm band), but rather falls more broadly within a broader neighborhood of the optical band, such as from ultraviolet to infrared (e.g., the wavelength of the optical radiation may be between about 100nm and about 10 μm).

"matrix camera" refers to a camera in which the pixels of the sensor are arranged according to a rectangular matrix having two dimensions of comparable length (e.g., the two dimensions differ by less than an order of magnitude, such as in a 16 x 9, 4 x 3, or 3 x 2 format). In an extension, a "matrix image" is a digital image acquired by a matrix camera.

The "optical axis" of a lens refers to the line along which the lens is rotationally symmetric.

"Linear laser source" refers to a laser source capable of emitting a linear laser beam, i.e. a laser beam that lies in a "propagation plane" and has a "propagation axis" as the propagation direction, which "propagation axis" belongs to the propagation plane and passes through the laser source. The intersection of the linear laser beam with a physical surface (e.g., a surface of an elongated element) having reflective/diffusive properties produces a "laser line".

Document US4718770 discloses a screw extruder comprising a feed section, the feed rollers of which run adjacent to the screw and counter to the rotation of the screw.

Document JP2008126541a discloses a method of feeding a strip-shaped elastomer into an extruder having a screw and a feed roller arranged parallel to the screw and counter-rotating with respect to the rotation of the screw.

Disclosure of Invention

Typically, the feed screw of a continuous processing machine is connected to or coincides with at least one processing screw of the machine. For example, in a planetary extruder the feed screw may coincide with the beginning of a central mandrel without satellites, or in a single screw extruder the feed screw may coincide with the beginning of the conveying and pushing screw itself. Thus, the rotational speed of the feed screw is typically determined by an adjustment (e.g., adjustment of the degree of mixing or adjustment of the extrusion amount) of the rotational speed of the processing screw due to the processing cause.

The inventors have observed that typically during feeding of a continuous elongated element to the feeding section of a continuous processing machine, the flow rate of the actually fed elongated element depends on the rotational speed of the feed screw, as the elongated element is caught and dragged by the feed screw. For example, as the feed screw rotational speed increases, an increase in the actual feed flow rate typically results, as the feed screw tends to drag a greater number of elongated elements into the machine (and vice versa).

Accordingly, the inventors have observed that when the rotational speed of the processing screw (or screws) varies due to processing reasons, an undesirable variation in the feed flow rate may occur.

As described in US4718770 and JP2008126541a, the possible presence of a feed roller adjacent to the feed screw increases this undesired dragging, since the feed roller cooperates with the feed screw of the extruder to accurately drag the elastomeric strip material into the mixing chamber of the extruder itself.

The inventors therefore felt the need to be able to mutually separate the rotation of the processing screw (and therefore of the feed screw) from the flow rate of the continuous elongated element actually fed, in order to improve and/or diversify the production process of the compound and/or the realization process of the semifinished product. For example, the inventors have realized that it is advantageous to be able to adjust the rotational speed of the feed screw while keeping the flow rate of the actually fed elongated element unchanged. In particular, given a certain feed flow rate of the elongated elements, it may be useful in a continuous process, for example in certain stages of the mixing process, to increase the rotational speed of the feed screw in order to enhance the mixing, but without increasing the feed flow rate at the same time (since in this case an increase in the degree of mixing will not be obtained, since more elongated element material will need to be mixed, with the result that a balance of the two effects is achieved).

Furthermore, the inventors have also noted that in the above case any dosing performed on the continuous elongated element upstream of the continuous processing machine may be damaged and/or distorted by the dragging effect of the feed screw.

The inventors are thus faced with the problem of feeding a continuous elongated element to a continuous processing machine in a controlled, autonomous manner, and independently of the type and/or parameters and/or process conditions (e.g. time trend of the process segments, rotational speeds of the components, such as the rotational speeds of the conveying and mixing screws, feeding of other ingredients, etc.), so as to diversify and/or improve the continuous processing and/or to be able to ensure an effective control of the flow rate of the actual feed (and thus also to be able to contribute to the possible dosing of the elongated element).

According to the present inventors, the above-mentioned problem is solved by a feeding device for a continuous elongated element, wherein the continuous elongated element is clamped between a pair of rollers which are rotated by and only by the action of a motor and a transmission.

According to one aspect, the application relates to a feeding device for a continuous elongated element.

The device comprises:

-a first roller and a second roller arranged side by side, the respective axes of rotation of which are substantially parallel to each other, wherein the first roller is movable relative to the second roller along a displacement direction to vary the mutual distance between the axes of rotation;

-a pushing actuator pushing the first roller towards the second roller, the pushing actuator acting on the first roller with an adjustable pushing force;

-a motor and a transmission mechanically connected to the first and second rollers for rotating the first and second rollers about respective axes of rotation at respective rotational speeds so as to limit or prevent variations in the respective rotational speeds of the first and second rollers due to an effect exerted on at least one of the first and second rollers other than the motor.

The expression "action not produced by said motor" refers to an action produced by any component independent of the motor and/or the feeding device, such as, and typically, an action exerted by the continuous elongated element on the roller (which produces a mechanical torque) when pulled by the continuous processing machine (for example by the feed screw).

According to one aspect, the invention relates to an apparatus, preferably for producing tyres, comprising a feeding device according to the invention and a continuous processing machine comprising a feed screw with a respective rotation axis, wherein the feeding device is arranged in proximity of the feed screw. Preferably, the continuous processing machine is one of: planetary extruders, twin-screw mixers, ring extruders, single-screw extruders, twin-screw extruders, feed extruders for fabric encapsulation calenders, extruders for semifinished products.

According to one aspect, the invention relates to a method for feeding a continuous elongated element.

The method comprises the following steps:

-providing a first roller and a second roller arranged side by side, the respective axes of rotation of the first roller and the second roller being substantially parallel to each other, wherein the first roller is movable relative to the second roller along a displacement direction to vary the mutual distance between the axes of rotation;

-arranging said continuous elongated element between said first and second rollers;

-pushing the first roller towards the second roller with an adjustable pushing force to clamp the continuous elongated element between the first and second rollers;

rotating the first and second rollers so as to advance the continuous elongated element to continuously feed the continuous elongated element to a feed point at a feed speed,

-controlling the respective rotational speeds of the first and second rollers so as to limit or prevent a variation in the respective rotational speeds due to the action of the continuous elongated element on at least one of the first and second rollers.

The expression "controlling … … rotational speed" means that the actual rotational speed imparted to the rollers is substantially equal to the desired value (e.g. given by a motor according to the particular implemented process), and it includes limiting or preventing variations in the rotational speed of the rollers due to the action exerted by said continuous elongated element on at least one of the rollers (i.e. not by the motor).

According to one aspect, the application relates to a tyre production process comprising a method for feeding a continuous elongated element according to the application.

According to the present inventors, the first and second rollers are arranged side by side and have respective axes of rotation parallel to each other, wherein the first roller is movable relative to the second roller along a displacement direction to vary the mutual distance between the axes of rotation, establishing the positioning interface (and subsequent feeding interface) of the elongated element in a simple manner. The change in the mutual distance between the rollers allows to create a space for inserting the continuous elongated element and subsequently to bring the first roller into contact with the elongated element. In this way, different sizes (typically thicknesses) and/or configurations of the elongated elements may be accommodated.

Pushing the first roller towards the second roller allows gripping the elongated element and also maintains such gripping (e.g. dynamically) as the dimensions of the elongated element (e.g. thickness of the elongated element) vary, for example following cross-sectional variations and/or surface defects such as protrusions and/or material defects. In this way, it is possible to advance the elongated element following the rotation imparted to the two rollers by the motor and transmission, reducing and/or avoiding slippage of the rollers with respect to the elongated element.

Furthermore, since the pushing force is adjustable, the elongated element may be clamped in a variable manner as desired and/or as a function of the material from which the elongated element is made (e.g. a soft material may require less pushing force than a harder and/or stronger material).

The control of the thrust force exerted on the first roller towards the other roller and the respective rotation speed (for example, the motor and the transmission are able to limit or prevent the variation of the respective rotation speed of the rollers due to the action of the non-motor exerted on at least one of the rollers) cooperate to prevent or limit the possibility of the elongated element being dragged by a component independent of the feeding device (for example, the feed screw of the continuous processing machine).

In fact, when the feed screw pulls the continuous elongated element at a speed greater than the feed speed given by the rotation of the rollers, it is possible to prevent the elongated element from slipping through both rollers themselves thanks to the thrust that keeps the rollers clamped on the elongated element, and moreover, thanks to the motor and transmission as described above, it is possible to brake or preferably prevent the dragging of the elongated element against the rollers and the excessive sliding of the elongated element caused thereby.

In this way, it is possible to feed the elongated element only after the motor and the transmission have applied rotation to the roller, and therefore in a controlled, autonomous manner, and independently of the type and/or parameters and/or conditions of the process.

In one or more of the above aspects, the invention may have one or more of the following preferred features.

Preferably, a feeding device according to the invention is provided.

Preferably, pushing the first roller toward the second roller is performed by the pushing actuator.

Preferably, rotating the first and second rollers and controlling the respective rotational speeds are performed by the motor and transmission.

Typically, the direction of advance of the continuous elongated element is generally aligned with the longitudinal dimension of said continuous elongated element.

Preferably, the cross section of the continuous elongated element substantially perpendicular to the advancing direction of the continuous elongated element has a parallelogram profile, more preferably rectangular and/or has short and long sides with a length ratio greater than or equal to 10 (i.e. the element is ribbon-shaped). Preferably, the first and second rollers contact the continuous elongated element at the long side (i.e. the axes of rotation of the rollers are generally parallel to the long side of the cross section of the elongated element).

Typically, the continuous elongated element is composed of a homogeneous material. Preferably, the continuous elongated element comprises or consists entirely of an elastomeric compound.

Preferably, the tyre production process comprises mixing (e.g. together with other ingredients or separately) or extruding the elastomer compound (e.g. by means of the continuous processing machine) after the feeding.

Preferably, said displacement direction is perpendicular to both said axes of rotation. Preferably, the thrust is oriented along the displacement direction. In this way, the first roller moves in a reasonable manner and maintains the bias towards the second roller.

Preferably, the motor includes first and second motor units that are different from each other and respectively include first and second motor shafts. For example, each motor unit may be: compressed air motors, electric motors (dc, ac, universal, brushless), hydraulic motors, internal combustion engines, and the like.

Preferably, the transmission is interposed between the motor and the first and second rollers to mechanically connect the motor with the first and second rollers. In this way, the driving force is distributed to the rollers.

In one embodiment, each roller is directly keyed to the motor shaft of the respective motor unit (in other words, the transmission coincides with the motor shaft and each motor unit is directly, mechanically connected to the respective roller).

Preferably, the transmission comprises a first transmission portion mechanically connecting the first motor unit to the first roller and a second (and different) transmission portion mechanically connecting the second motor unit to the second roller. In this way, each roller is independently motorized. Preferably, the first transmission portion and the first motor unit are integral with the first roller. In this way, a movement of the first roller in the displacement direction is facilitated, since the first motor unit and the first transmission part can also be moved together with the first roller independently of the second roller and the respective second motor unit and second transmission part. In this way, the feeding device is manufactured in a simple manner.

In an alternative embodiment, the motor comprises one and only one motor unit. In this case, preferably, the transmission is configured to allow the first roller to move in the displacement direction while keeping the first and second rollers mechanically connected to the only one motor unit. For example, the transmission may comprise a chain transmission suitably sized in a dynamic manner to allow such movement of the first roller while maintaining a mechanical engagement with the only one motor unit.

Preferably, the transmission comprises at least one input shaft and at least one output shaft, wherein preferably the input shaft receives rotation from the motor and the output shaft rotates the first and second rollers.

Preferably, the first and second transmission portions include respective first and second input shafts and respective first and second output shafts.

Preferably, the first and second input shafts are mechanically, more preferably rigidly, connected to the first and second motor shafts, respectively, so as to rotate together, more preferably integrally, with the first and second motor shafts.

Preferably, the first and second output shafts are mechanically, more preferably rigidly, connected to the first and second rollers, respectively, for rotating the first and second rollers.

The expressions "input shaft", "output shaft" refer to the direction of distribution of the driving force (i.e. from the motor through the transmission to the rollers).

Preferably, the transmission, more preferably each of the first and second transmission portions, comprises a mechanical coupling between the respective input shaft and the respective output shaft for transmitting rotation of the respective input shaft to the respective output shaft so as to limit or prevent rotation of the respective output shaft not transmitted by the respective input shaft. Preferably, the mechanical coupling comprises a worm gear type gear coupling (for example, the input shaft is equipped with a worm, the output shaft is integral with or connected to a gear engaged to the worm) arranged successively (proceeding) from the respective input shaft to the respective output shaft, more preferably the mechanical coupling is constituted by the above-mentioned gear coupling. In this way, the rotation of the worm follows the rotation of the gear, which in turn transmits the rotation to the roller. At the same time, the worm mechanically prevents rotation of the gear when the gear is subjected to mechanical torque other than from the worm. In this way, it is achieved in a structurally simple manner that the respective rotational speeds of the first roller and the second roller are prevented from varying due to the non-motor-generated action exerted on at least one of the rollers.

Alternatively or additionally, when the motor shaft is subjected to a torque that is "external" to the motor (i.e., not provided by the motor), the motor itself (e.g., the first and/or second motor units) can apply a braking action to apply rotation to the roller independent of the external torque.

In one embodiment, the transmission may comprise a single input shaft for a single motor shaft of only one motor unit and a respective output shaft for each of said first and second rollers. In this case, preferably, the transmission comprises a respective mechanical coupling between the single input shaft and each respective output shaft, the respective mechanical coupling comprising at least one, more preferably all, of the above-mentioned features of the mechanical coupling of each of the first and second transmission parts.

Preferably, the transmission, more preferably each of the first and second transmission portions, is free of clutch members. In this way, the motor remains engaged with the roller at all times, further reducing the risk that the rotational speed of the roller may change due to non-motorized application.

Preferably, each of said first and second transmission parts comprises, more preferably consists of, a respective gearbox. In one embodiment, the reduction ratio of each gearbox is greater than or equal to 1:50, more preferably greater than or equal to 1:40, and/or less than or equal to 1:20, more preferably less than or equal to 1:30. In this way, a desired drag torque can be obtained at the roller (e.g. depending on the material from which the elongated element is made, typically on the viscosity of this material).

Preferably, each of said first and second transmission portions is mechanically connected to a respective roller at a first longitudinal end thereof.

Typically, the rotation of the first and second rollers has opposite directions (i.e., the rollers counter-rotate).

Preferably, the rotation of the first and second rollers is such that the linear velocities of the respective side surfaces of the first and second rollers are substantially (i.e. less than 10% of theoretical) equal to each other. Typically, the first and second rollers have radii and respective rotational speeds equal to each other. In this way, the feeding of the elongated element is facilitated, thereby reducing the risk that the roller may incorrectly drag, for example, which may scratch the surface of the elongated element.

Preferably, the feeding device comprises angular position sensors for the first and second rollers, respectively, for measuring the angular positions of the first and second rollers, respectively (e.g. encoders). The angular position may be measured directly on the roller or indirectly, i.e. on an element (e.g. the first and second motor shaft, the first and second input shaft, the first and second output shaft, etc.) having a respective angular position that is uniquely related to the above-mentioned angular position of the roller.

Preferably, the feeding device comprises a command and control unit connected to the motor (more preferably to both the first and second motor units) and to each angular position sensor. Preferably, the command and control unit is programmed to command the motor at least as a function of the measurements of each angular position sensor. In this way, the rotation of the first roller and the second roller may be substantially synchronized.

Preferably, for each of the first and second rollers, the feeding device comprises a respective set of bearings (e.g. ball bearings, magnetic bearings, etc.) arranged at a first longitudinal end of the respective roller and/or at a second longitudinal end of the respective roller opposite to the first longitudinal end. In this way, the roller is supported while the roller rotation is promoted.

Preferably, each of said first and second rollers comprises a respective side surface which extends in a cylindrically symmetrical manner about a respective rotation axis. In use, the side surface of each roller is arranged to be in contact with the continuous elongate element.

Preferably, the side surface has a cylindrical extension. In this way the contact area with the elongated element is maximized.

In an alternative embodiment, the side surface has a toothed extension, i.e. it has a plurality of radial reliefs, preferably having right angles, wherein the reliefs of the first roller are staggered with respect to the reliefs of the second roller. In this way, the elongated element is cut into a plurality of strips along the advancing direction, facilitating the capture by the feed screw.

Preferably, said side surfaces of said first and second rollers are configured for gripping said continuous elongated element. Preferably, the side surfaces of the first and second rollers have a surface treatment (e.g. the side surfaces are knurled or embossed) for increasing the coefficient of friction (e.g. the static coefficient of friction) with the continuous elongated element. In this way, the retention of the elongated element by the two rollers increases due to the thrust.

In one embodiment, the length of the first roller that can move along the displacement direction is greater than or equal to 5mm, more preferably greater than or equal to 10mm, and/or less than or equal to 30mm, more preferably less than or equal to 25mm.

In one embodiment, the minimum distance between the side surfaces of the first and second rollers is greater than or equal to 2mm, more preferably greater than or equal to 4mm, even more preferably greater than or equal to 5mm, by virtue of the movement of the first roller. In one embodiment, the maximum distance between the side surfaces of the first and second rollers by virtue of the movement of the first roller is less than or equal to 40mm, more preferably less than or equal to 30mm, even more preferably less than or equal to 25mm. In this way, elongated elements of various sizes (e.g. thickness) can be fed.

Preferably, the feeding device comprises a base body, more preferably rigid, which extends in a longitudinal direction, a transverse direction and a height, respectively. Typically, the longitudinal direction, the transverse direction and the height are substantially perpendicular to each other.

Preferably, the first roller is movable relative to the substrate. In one embodiment, the second roller is also movable relative to the base body to vary the mutual distance between the axes of rotation. In this way, the travel of each roller can remain limited.

Preferably, the base comprises a first and a second seat for respectively at least partially housing the first and the second roller.

Preferably, the first and second seats have respective main directions of extension, which are substantially parallel to the longitudinal direction of extension of the base body.

Preferably, the axes of rotation of the first and second rollers are each substantially parallel to the longitudinal direction. In this way, the rollers reasonably occupy their respective seats.

Preferably, the displacement direction is substantially parallel to the transverse direction. In this way, the first roller is reasonably moved relative to the substrate.

Preferably, the base comprises a through hole having an inlet mouth and an outlet mouth arranged on opposite sides of the base along the height. Preferably, the through hole is interposed between the first and second seats, which communicate with the through hole, more preferably adjoin the through hole. In this way, a channel is made through the substrate, suitably arranged so that the continuous elongated element is interposed between the first roller and the second roller.

Preferably, the through-hole extends substantially along the height. In this way a substantially straight channel is created for the elongated element.

Preferably, the first and second rollers at least partially block the through-hole (preferably narrowing a section of the through-hole). In this way, the first roller and the second roller are able to interact with the elongated element inside the through hole.

Preferably, the first seat portion includes a first portion remote from the through hole and having an opposite shape to a circumferential portion of the side surface of the first roller. Preferably, the first seat comprises a second portion adjoining the first portion, the second portion being adjacent (more preferably adjoining) the through hole and shaped to provide a guide for the first roller to slide along the displacement direction. In this way, the first roller can slide along the first seat to vary the degree of obstruction to the through hole.

Preferably, the shape of the second seat is opposite to the circumferential portion of the side surface of the second roller. This saves space to reduce overall interference.

Alternatively, the base body may comprise a further through hole, more preferably with respective inlet and outlet mouths arranged on opposite sides of the base body along the height. In this way, further elements (typically discontinuous elongated elements, such as granular elements) may be fed.

Preferably, the side surfaces of the first and second rollers are accessible only through the through-hole (e.g., through the inlet nozzle). In other words, the substrate surrounds the first and second rollers except at the through holes. In this way, the moving parts of the device are enclosed within the matrix, increasing its inherent safety.

Preferably, the base body comprises a set of base elements which can be assembled together to form the base body, wherein the base elements have a major planar extent along the longitudinal direction and the transverse direction and they are stacked along the height. In this way, the entire device can be assembled in a simple manner by stacking the base elements.

Preferably, the set of foundation elements comprises at least three foundation elements, more preferably three and only three foundation elements.

In one embodiment, the length of the inlet mouth of the through-hole along the longitudinal direction is greater than or equal to 20cm, more preferably greater than or equal to 60cm, such as greater than or equal to 90cm, and/or less than or equal to 150cm, more preferably less than or equal to 120cm, such as less than or equal to 100cm. The above dimensions allow easy feeding of elongated elements having various dimensions (typical transverse widths between slightly less than 20cm and about 120 cm).

Preferably, the base body comprises respective housing seats for the transmission and for the set of bearings, respectively.

Preferably, one or more (more preferably at least two) base elements comprise respective recesses shaped for forming the first and second seats and/or the housing seat together with the base elements assembled together to form the base body. In this way, a seat, for example a housing seat, typically a set of bearings, can be achieved that is substantially entirely inside the base body and/or has a significant undercut, for example to increase the intrinsic safety of the feeding device and/or to further limit its encumbrance.

Preferably, the base element comprises male-female coupling parts at mutually facing surfaces, which male-female coupling parts are shaped to center the base element with respect to each other in longitudinal and transverse directions. In this way, stacking of the base elements becomes easier.

Preferably, the base element of the base body, more preferably of the outlet mouth comprising the through hole, comprises a thermal conditioning circuit, more preferably a thermal conditioning circuit for cooling. In fact, the feeding device is typically arranged in the vicinity of a continuous processing machine, which is usually operated at high temperatures, which may be detrimental to the feeding device. In the case of this thermally regulated base element, it acts as a thermal insulator for the remaining base element.

Preferably, the push actuator comprises a first actuator element operatively connected to a first longitudinal end of the first roller, more preferably it further comprises a second actuator element operatively connected to a second longitudinal end of the first roller opposite to the first longitudinal end. For example, each actuator element may be a hydraulic or pneumatic piston (preferably having a double action) or a linear electric actuator. In this way, the movement of the first roller is easily controlled, and the thrust force can be uniformly applied to the first roller.

Preferably, the thrust is adjusted according to the viscosity of the continuous elongated element. In this way, it is possible to adapt the device to various elongated elements, facilitating their feeding and reducing the risk of damaging the elongated elements and/or not providing a thrust sufficient to move the elongated elements.

Preferably, the command and control unit is connected to the push actuator to adjust the thrust force according to a value representative of the viscosity of the continuous elongated element. The value representing the viscosity may be measured and transmitted directly to the command and control unit or manually entered by an operator.

According to one aspect, the invention relates to a feeding device for a continuous elongated element, comprising an advancing system for advancing said continuous elongated element in an advancing direction along a first passage, said advancing system comprising a feeding means according to the invention, arranged at an outlet of the first passage, for continuously feeding said continuous elongated element at a feeding speed to a feeding point corresponding to said outlet of said first passage.

The terms "upstream", "downstream", "in-between, start, end positions", "inlet", "outlet" and the like refer to the relative position or arrangement between elements and/or regions of the apparatus with reference to the direction of advance of the continuous elongated element.

Preferably, the feeding device comprises a measuring system for continuously measuring on said continuous elongated element an amount suitable for evaluating the actual flow rate of said continuous elongated element continuously fed to said feeding point.

"flow rate" of a continuous elongated element refers to the amount (in terms of volume or mass, both of which are related by the density of the material) of the continuous elongated element that is conveyed through a location per unit time.

Preferably, the feeding device comprises a respective command and control unit connected to said advancing system and to said measuring system and programmed for continuously commanding said advancing system to continuously adjust said feeding speed according to said measured quantity and a reference value of the feeding flow rate of said continuous elongated element in said feeding point.

In this way, the feeding device can dose the continuous elongated element, i.e. it can feed the continuous elongated element continuously to the feeding point (for example to the continuous processing machine) by controlling its actual flow rate.

In fact, in the case of "irregular" continuous elongated elements (i.e. having a cross section that varies longitudinally along the elongated element), for some applications it may not be sufficient to control the feed speed to control the actual flow rate. The above-described feeding device also allows dosing of "irregular" elongated elements thanks to the measurement of the quantity suitable for evaluating the actual flow rate and to the control of the feeding speed according to this quantity, and thanks to the feeding device according to the invention.

The expression "continuously" in relation to an operation in relation to a continuous elongated element means that the operation is repeated closely in time in order to spatially resolve the elongated element in a suitable way, for example such that the operation is performed on consecutive contiguous points of the order of centimeters or even less than one centimeter from each other in the longitudinal direction of the elongated element.

Preferably, the command and control unit of the feeding device is operatively connected to said command and control unit of the feeding apparatus, more preferably comprises said command and control unit of the feeding apparatus.

Preferably, said quantity comprises, more preferably corresponds to, geometric information sufficient to calculate, at least in an approximate manner, a value representative of the area range of a section of said continuous elongated element on a plane substantially perpendicular to said advancing direction.

Preferably, the measuring system comprises at least one optical detection device for continuously detecting the geometrical information in detection points along the first path. In this way, a non-contact detection is performed so as not to interfere with the advancement of the elongated element.

In an alternative embodiment, the quantity may be a mass per unit length (i.e., the measurement system dynamically weighs the longitudinal path of the continuous elongated element as it advances).

Preferably, the geometrical information comprises a height distribution of at least a portion of the profile of the cross section relative to a reference height. In this way, the area range of the cross section can be calculated taking into account the actual distribution of at least a portion of the profile of the cross section. In this way, possible defects of the elongated element (e.g. surface defects such as lack and/or excess of material, variations in cross-sectional shape, etc.) may be included in the calculation of the area range to improve the accuracy of calculating the area range of the cross-section.

Preferably, the optical detection device comprises a matrix camera having an optical axis and a linear laser source capable of emitting a linear laser beam having a propagation axis (arranged at a specific angle, for example 40 °) with respect to the optical axis. In this way, the geometrical information can be obtained by means of laser triangulation, which allows a line through the surface of the elongated element to be scanned, i.e. substantially punctiform (functal) along the longitudinal dimension, to obtain a height distribution of at least a portion of the profile of the cross section (and thus of the surface of the elongated element as it advances).

In an embodiment, the geometrical information comprises a height distribution of the (substantially entire) contour of the cross-section. Preferably, the measuring system comprises further optical detection means arranged on the opposite side of the continuous elongated element with respect to the optical detection means. Preferably, the further optical detection device comprises the same features of the optical detection device described above. In this way, the accuracy of the detection of the geometrical information by means of laser triangulation is improved, since it is also possible to detect possible surface defects on the other surface of the elongated element (e.g. up to substantially the entire geometrical profile of the detection section).

Preferably, said command and control unit of said feeding device is programmed to calculate continuously, from said geometric information, a value representative of the area range of said section. In this way, as an area range of the substantially punctiform cross-section along the advancing direction, a high dosing accuracy can be achieved, since the actual flow rate can be evaluated in a substantially punctiform manner (as described below).

Preferably, said command and control unit of the feeding device is programmed to continuously calculate the theoretical value of the feeding speed from the ratio between said reference value of the feeding flow rate and said value representative of the area range of the cross section. In this way, the actual flow rate at the feed point can be implicitly estimated and compared with a reference value for the feed flow rate.

Preferably, continuously adjusting the feed speed comprises setting the feed speed equal to the theoretical value. In this way, the flow rate actually fed to the feed point corresponds to the desired flow rate value.

Preferably, continuously commanding the advancing system for continuously adjusting the feed speed comprises continuously (only) commanding the feed device, more preferably continuously commanding the motor (more preferably each of the first and second motor units, even more preferably in a mutually independent manner) for adjusting (e.g. accelerating, decelerating) the rotation of the first and second rollers.

Preferably, said command and control unit of the feeding device is programmed for calculating (more preferably according to said feeding speed) the time delay taken by said section to travel from said detection point to said feeding point. Preferably, the command and control unit of the feeding device is programmed for continuously commanding the advancing system in order to continuously adjust the feeding speed also according to the time delay (more preferably when the section has reached the feeding point). In this way the physical extension of the feeding device is taken into account when adjusting the feeding speed (since the area range of the cross section is calculated at detection points that normally do not correspond to the feeding point).

Drawings

The features and advantages of the invention will be further clarified by the following detailed description of some embodiments presented by way of non-limiting example of the invention with reference to the accompanying drawings, in which:

fig. 1 schematically shows a section (taken along the plane BB of fig. 2) of a feeding device according to the invention;

fig. 2 schematically shows a top view of the feeding device of fig. 1;

fig. 3 schematically shows a perspective view of some components of the feeding device of fig. 1;

fig. 4 schematically shows an arrangement according to the invention;

fig. 5 schematically shows a feeding device according to the invention.

Detailed Description

In the figures, the numeral 999 indicates as a whole a feeding device for a continuous elongated element 900.

Illustratively, the continuous elongated element 900 is constructed from a ribbon-like element made of a homogeneous green elastomer composite. Illustratively (fig. 2), the cross section 200 of the continuous elongated element perpendicular to the advancing direction 100 of the continuous elongated element (in fig. 2, with the direction into the plane of the paper) is generally rectangular (ignoring possible surface imperfections, not shown), for example rectangular with long sides of about 20cm long and short sides of about 3cm high.

The feeding device 999 comprises, for example, a first roller 1 and a second roller 2, which are arranged side by side and each have a rotation axis 101, 102 (indicated by the symbol + in fig. 1) parallel to each other, wherein the first roller 1 is movable relative to the second roller 2 along a displacement direction 103, which is, for example, perpendicular to the two rotation axes 101, 102, in order to change the mutual distance D between the rotation axes 101, 102.

Illustratively, the first roller 1 and the second roller 2 each have a respective side surface 4 which extends in a cylindrically symmetrical manner about a respective rotation axis 101, 102. Illustratively, in use, the side surface 4 of each roller is disposed in contact with the continuous elongated element 900 at the long side of the continuous elongated element (fig. 2 and 3).

Illustratively, the side surfaces 4 have a cylindrical extension and they are configured for gripping the continuous elongated element 900. For this purpose, the side surfaces 4 of the first roller 1 and the second roller 2 are illustratively provided with a surface treatment (schematically represented in fig. 2 and 3 by means of cross-hatching) for increasing the coefficient of static friction with the continuous elongated element 900 (for example, the side surfaces are knurled or embossed).

The feeding device 999 comprises, for example, a pushing actuator 5 pushing the first roller 1 towards the second roller 2, said pushing actuator acting on the first roller 1 with an adjustable pushing force oriented along the displacement direction 103.

Illustratively, the first roller 1 may be moved along the displacement direction 103 by a total length of about 20 mm.

By way of example, the minimum distance between the side surfaces 4 of the first roller 1 and the second roller 2 is about 5mm and the maximum distance is about 25mm by means of the movement of the first roller 1.

The push actuator 5 comprises an actuator element 6, which is constituted by a double-acting pneumatic piston (only schematically shown), which is operatively connected to a first longitudinal end 7 of the first roller 1, for example.

Illustratively, the feeding device 999 comprises a motor 8 and a transmission 14 mechanically connected to the first roller 1 and the second roller 2 to rotate the first roller 1 and the second roller 2 about respective rotation axes 101, 102 at respective rotation speeds so as to limit or prevent a variation in the respective rotation speeds of the first roller 1 and the second roller 2 due to the action exerted on at least one of the first roller and the second roller by the non-motor 8.

Illustratively, a transmission 14 is interposed between the motor 8 and the first roller 1 and the second roller 2 to mechanically connect said motor with said first roller and said second roller.

Illustratively, the motor 8 comprises a first motor unit 10 and a second motor unit 11 (schematically shown in fig. 2 and 3) comprising a first motor shaft 12 and a second motor shaft 13, respectively.

The transmission 14 comprises, as an example, a first transmission part 15 mechanically connecting the first motor unit 10 to the first roller 1 and a second transmission part 16 mechanically connecting the second motor unit 11 to the second roller 2. Illustratively, the first transmission portion 15 and the first motor unit 10 are integral with the first roller 1.

Illustratively, the first and second transmission portions 15, 16 include respective first and second input shafts 17, 18 and respective first and second output shafts 19, 20.

Illustratively (fig. 3), the first and second input shafts 17, 18 are rigidly and mechanically connected to the first and second motor shafts 12, 13, respectively, for rotation integrally therewith, and the first and second output shafts 19, 20 are rigidly and mechanically connected to the first and second rollers 1, 2, respectively, for rotation thereof.

Illustratively, each drive portion 15, 16 includes a mechanical coupling (not shown) between the respective input shaft 17, 18 and the respective output shaft 19, 20 for transmitting rotation of the respective input shaft 17, 18 to the respective output shaft 19, 20 so as to limit or prevent rotation of the respective output shaft 19, 20 transmitted by the non-respective input shaft 17, 18. Illustratively, the mechanical coupling consists of a gear coupling of the worm gear type arranged successively from the respective input shaft 17, 18 to the respective output shaft 19, 20 (for example, not shown, the input shaft is equipped with a worm, the output shaft is integral with a gear meshing with the aforementioned worm). In this way, the geometry of the mechanical coupling physically prevents rotation of the respective output shaft not transmitted by the respective input shaft (rotation of the gear is prevented because it cannot produce a corresponding rotation of the worm around the respective axis, but only allows the movement to be transmitted in the opposite direction, i.e. from worm to gear).

Illustratively, each of the drive portions 15, 16 is devoid of clutch members.

Illustratively, each drive section 15, 16 is formed from a respective gearbox having a reduction ratio equal to 1:40 (i.e., torque applied by a respective motor shaft connected to the drive section multiplied by 40 is torque at the output of the gearbox, while the rotational speed of the input shaft divided by 40 is the rotational speed at the output shaft of the gearbox. In jargon, such motor-gearbox coupling is referred to as a gear motor).

Illustratively (fig. 2 and 3), each transmission portion 15, 16 is mechanically connected to the respective roller 1, 2 at a first longitudinal end 7, 87 of the respective roller.

Illustratively, the feeding device 999 comprises for each roller a respective angular position sensor 50 (e.g. an encoder) for measuring the angular position of the first roller 1 and the second roller 2, respectively. Illustratively, this angular position is measured indirectly at a first output shaft 19 and a second output shaft 20, which are rigidly connected to the respective rollers, with respective angular positions that are uniquely related to the above-mentioned angular positions of the rollers.

Illustratively, the feeding device 999 comprises a command and control unit 60 connected to the first motor unit 10 and the second motor unit 11 and to each angular position sensor 50.

Illustratively, for each roller, the feeding device 999 comprises a set of ball bearings 70 arranged at a first longitudinal end 7, 87 (not shown) of the respective roller and at a second longitudinal end of the respective roller opposite to the first longitudinal end 7, 87.

Illustratively, the feeding device 999 comprises a rigid matrix 21 extending along a longitudinal direction 201, a transverse direction 202 and a height 203, respectively, perpendicular to each other.

Illustratively, the first roller 1 is movable relative to the base 21.

Illustratively, the base 21 comprises a first seat 22 and a second seat 23 shaped to house, at least in part, the first roller 1 and the second roller 2, respectively, the first seat 22 and the second seat 23 illustratively having respective main directions of extension substantially parallel to the longitudinal direction 201 of extension of the base 21.

Illustratively, the rotational axes 101, 102 of the first roller 1 and the second roller 2, respectively, are parallel to the longitudinal direction 201, and the displacement direction 103 is parallel to the transverse direction 202.

Illustratively, the base 21 includes a through-hole 24 extending along the height 203 and having an inlet mouth 25 and an outlet mouth 26 disposed on opposite sides of the base 21 along the height 203. Illustratively, a through hole 24 is interposed between the first seat 22 and the second seat 23, which communicate with and adjoin the through hole 24.

Illustratively, the length L of the inlet mouth 25 along the longitudinal direction 201 is equal to about 30cm.

Illustratively, the first roller 1 and the second roller 2 partially block the through-hole 24 while being accommodated in the first seat 22 and the second seat 23, respectively, thereby narrowing a section of the through-hole 24.

Illustratively, the first seat 22 comprises a first portion 27 remote from the through hole 24 and of opposite shape to the circumferential portion of the side surface 4 of the first roller 1, and a second portion 28, adjacent to the first portion 27 and to the through hole 24, shaped to make a sliding guide of the first roller 1.

Illustratively, the second seat 23 is of an opposite shape to the circumferential portion of the side surface 4 of the second roller 2.

Illustratively, the base 21 includes another through-hole 29 having respective inlet mouths 30 (shown in fig. 2) and respective outlet mouths (not shown) disposed on opposite sides of the base 21 along the height 203.

Illustratively, the side surfaces 4 of the first roller 1 and the second roller 2 are only accessible through the through-holes 24 (e.g., through the inlet mouths 25).

Illustratively, the base 21 includes a set of three base elements 31 that can be assembled together to form the base 21. Illustratively, the base element 31 has a major planar extent (e.g., plate) along the longitudinal direction 201 and the transverse direction 203, and is stacked along the height 203.

Illustratively, the base 21 includes respective housing seats 32, 33 for the transmission 14 and for the set of ball bearings 70, respectively.

Illustratively, the two base elements 31 (e.g., first and second base elements 31, fig. 1, arranged successively along the height 203 in a direction coincident with the advancing direction 100) comprise respective recesses shaped for forming the first and second seats 22, 23 and the housing seats 32, 33 together with the base element 31 assembled to form the base 21. Illustratively, once the base element 31 is assembled, the housing seats 33 of the set of ball bearings 70 are seated inside the base 21, while the housing seats 32 of the transmission 14 are in communication with the outside (for example, open in correspondence with at least one of its upper surfaces).

Illustratively, as shown in fig. 1, the base element 31 comprises male-female coupling portions at mutually facing surfaces, which are shaped to center the base element 31 relative to each other along a longitudinal direction 201 and a transverse direction 202.

Illustratively, the base member 31 of the outlet nozzle 26 containing the through bore 24 includes a cooling circuit (not shown).

In use, the feeding device 999 allows to perform a method for feeding a continuous elongated element 900.

Illustratively, the continuous elongated element 900 is arranged between the first roller 1 and the second roller 2, and the first roller 1 is pushed towards the second roller 2 with a pushing force by the pushing actuator 5 for clamping the continuous elongated element 900 between the first roller 1 and the second roller 2.

Illustratively, the thrust is adjusted according to the viscosity of the continuous elongated element. For this purpose, a command and control unit 60 is illustratively connected to the push actuator 5 to adjust the thrust according to a value representative of the viscosity of the continuous elongated element.

Illustratively, the motor 8 is activated to rotate the first roller 1 and the second roller 2 to advance the continuous elongated element 900 to continuously feed the continuous elongated element to the feed point a at a feed speed.

Illustratively, the respective rotational speeds of the first roller 1 and the second roller 2 are controlled (e.g., by the motor 8 and the transmission 14) so as to limit or prevent variations in the respective rotational speeds due to the action of the continuous elongated element 900 on at least one of the rollers.

Illustratively, the rotation of the first roller 1 and the second roller 2 has opposite directions (i.e., the rollers counter-rotate) and the linear velocities of the side surfaces 4 of the first roller 1 and the second roller 2 are made equal to each other. Illustratively, the radii and the respective rotational speeds of the first roller 1 and the second roller 2 are equal to each other.

Illustratively, the command and control unit 60 is programmed to command the first motor unit 10 and the second motor unit 11 in accordance with the measurements of each angular position sensor 50.

Referring to fig. 4, numeral 90 generally designates an apparatus comprising a feeding device 999 according to the present invention and a continuous processing machine 80 comprising a feed screw 81 (also shown in fig. 1) having respective axes of rotation 105, wherein the feeding device 999 is arranged in the vicinity of the feed screw 81. Illustratively, the continuous processing machine 80 is a planetary extruder, and the feed screw 81 illustratively coincides with a start portion 82 of a satellite-free central spindle.

With reference to fig. 5, numeral 99 indicates as a whole a feeding device for a continuous elongated element 900, comprising an advancing system 91 for advancing the continuous elongated element 900 in an advancing direction 100 along a first passage 110, the advancing system 91 comprising a feeding device 999 according to the invention, arranged at the outlet of the first passage 110, for continuously feeding the continuous elongated element 900 at a feeding speed to a feeding point a corresponding to the outlet of the first passage 110.

Illustratively, the feeding apparatus 99 comprises a measuring system 92 for continuously measuring on the continuous elongated element an amount suitable for evaluating the actual flow rate of the continuous elongated element continuously fed to the feeding point a.

Illustratively, the amount suitable for assessing the actual flow rate of the continuous elongated element corresponds to geometric information related to the cross section 200 of the continuous elongated element 900. Illustratively, the geometric information includes a height profile of at least a portion (not shown) of the profile of the cross-section 200 relative to a reference height (e.g., a side surface of the support roller 403 of the advancement system 91 on which the elongated element is resting).

Illustratively, the measuring system 92 comprises a single optical detection device 94 (schematically shown) for continuously detecting the height distribution of the portion of the profile of the section facing the optical detection system 94 with respect to the side surface of the support roller 403 in the detection points R along the first path 110. For this purpose, the optical detection device 94 is illustratively based on laser triangulation techniques, and comprises a matrix camera (not shown) having an optical axis 300 and a linear laser source (not shown) adapted to emit a linear laser beam 301 having a propagation axis (illustratively forming an angle of about 40 ° with the optical axis 300).

In one embodiment (not shown), the measuring system may comprise a further optical detection device comprising the same features as the optical detection device described above and arranged on the opposite side of the elongated element with respect to the single optical detection device 94 (i.e. below the elongated element) for detecting the height distribution of a further portion of the profile of the cross section at a further detection point offset with respect to the support roller 403 along the longitudinal extension of the elongated element (so that the support roller does not interfere with the detection).

Illustratively, the feeding device 99 comprises a respective command and control unit 93 connected to the advancing system 91 and to the measuring system 92, said command and control unit illustratively comprising the command and control unit 60 of the feeding means 999.

Illustratively, the command and control unit 93 of the feeding device 99 is programmed for continuously commanding the advancing system 91 for continuously adjusting the feeding speed according to the quantity measured by the measuring system 92 and the reference value of the feeding flow rate of the continuous elongated element 900 at the feeding point a.

For example, the command and control unit 93 of the feeding device 99 is exemplarily programmed for continuously calculating a value representing the area range of the cross section 200 from the height distribution, and for continuously calculating a theoretical value of the feeding speed from the ratio between the reference value of the feeding flow rate and the value representing the area range of the cross section 200. Illustratively, continuously adjusting the feed speed includes setting the feed speed equal to a theoretical value, and continuously commanding the advancement system 91 to continuously adjust the feed speed illustratively includes continuously commanding each of the motor units 10, 11 to adjust (e.g., accelerate, decelerate) the rotation of the first roller 1 and the second roller 2.

Illustratively, the command and control unit 93 of the feeding device 99 is programmed for calculating, from the feeding speed, the time delay taken by the section 200 to travel from the detection point R to the feeding point a, and for continuously commanding the advancing system 91 to continuously adjust the feeding speed also according to the time delay described above (for example, when the section 200 has reached the feeding point a).

Illustratively, the first passageway 110 includes a detection portion 111 including a detection point R, wherein illustratively, an entrance of the detection portion 111 coincides with an entrance of the first passageway 110. Illustratively, the first passageway 110 includes a buffer portion 112 disposed downstream of and continuous with the detection portion 111, wherein illustratively, an outlet of the buffer portion 112 coincides with an outlet of the first passageway 110.

Illustratively, the advancement system 91 is adapted to subject the continuous elongated element to tension along both the detection portion 111 and along the buffer portion 112, wherein illustratively, the reference tension along the buffer portion 112 is less than the reference tension along the detection portion 111 (as shown by the curvature formed by the elongated element). The lower tension along the buffer portion 112 provides sufficient material to avoid that the elongated element may be excessively stretched (which may damage the elongated element and/or break the elongated element) after the feed rate is adjusted by the advancing device 999.

Illustratively, the feeding apparatus 99 includes respective tension sensors 95, 96 for the detection portion 111 and the buffer portion 112, respectively, adapted to continuously (e.g., contactlessly) detect the tension of the continuous elongated element along a respective one of the detection portion 111 and the buffer portion 112.

Illustratively, a command and control unit 93 of the feeding apparatus 99 is connected to each tension sensor 95, 96.

Illustratively, advancement system 99 includes respective advancement means 97, 98 for detection portion 111 and buffer portion 112, respectively, disposed at the entrances of detection portion 111 and buffer portion 112, respectively, and configured for adjusting the advancement of the continuous elongated element. Illustratively, advancing devices 97 and 98 are configured for braking and advancing, respectively, the continuous elongated element.

Illustratively, each advancing device 97, 98 is configured for gripping a continuous elongated element. Illustratively, each advancing means 97, 98 comprises a main roller M controllable by the command and control unit 93 of the feeding device 99 and a further roller F arranged parallel to the main roller M and kept pushed against the main roller M (alternatively, this further roller may also be controllable by the command and control unit 93 of the feeding device 99).

Illustratively, the command and control unit 93 of the feeding apparatus 99 is further programmed for continuously comparing the tension detected along the detecting portion 111 and the buffering portion 112, respectively, with a corresponding reference tension and for continuously commanding the corresponding advancing means 97, 98 in accordance with a corresponding comparison between the tension detected along the detecting portion 111 and the buffering portion 112, respectively, and the corresponding reference tension.

Illustratively, the feeding apparatus 99 includes a centering portion upstream of the first passageway 110 for centering the elongated element. At this centring portion, the feeding device 99 illustratively comprises a further advancing means 400 for unloading the elongated element by dragging it from possible storage means (not shown, for example a tray, reel, etc.), a further tension sensor 401 for detecting the tension of the elongated element along the centring portion, and a pair of rollers with vertical axes 402 (only one visible) for centring the elongated element (for example by twisting) in cooperation with the further advancing means 400 and/or with the advancing means 97 at the inlet of the detecting portion 111. Illustratively, the command and control unit 93 of the feeding apparatus 99 is connected to the further detecting device 400 and the further tension sensor 401.

Claims

1. A feeding device (999) for a continuous elongated element (900), comprising:

-a first roller (1) and a second roller (2) arranged side by side, the respective axes of rotation (101, 102) of which are substantially parallel to each other, wherein the first roller (1) is movable relative to the second roller (2) along a displacement direction (103) in order to vary the mutual distance (D) between the axes of rotation (101, 102);

-a pushing actuator (5) pushing the first roller (1) towards the second roller (2), the pushing actuator acting on the first roller (1) with an adjustable pushing force;

-a motor (8) and a transmission (14), said motor and said transmission (14) being mechanically connected to said first roller (1) and to said second roller (2) for rotating said first roller (1) and said second roller (2) about said respective axes of rotation (101, 102) at respective rotational speeds so as to limit or prevent a variation in the respective rotational speeds of said first roller (1) and said second roller (2) due to an action exerted on at least one of said first roller (1) and said second roller (2) other than said motor (8).

2. The feeding device (999) according to claim 1, wherein the displacement direction (103) is perpendicular to both of the respective rotation axes (101, 102), and wherein the thrust force is oriented along the displacement direction (103).

3. The feeding device (999) according to claim 1, wherein the motor (8) comprises a first motor unit (10) and a second motor unit (11) comprising a first motor shaft (12) and a second motor shaft (13), respectively, wherein the transmission (14) is interposed between the motor (8) and the first roller (1) and the second roller (2) to mechanically connect the motor with the first roller and the second roller, wherein the transmission (14) comprises a first transmission portion (15) mechanically connecting the first motor unit (10) to the first roller (1) and a second transmission portion (16) mechanically connecting the second motor unit (11) to the second roller (2), and wherein the first transmission portion (15) and the first motor unit (10) are integral with the first roller (1).

4. A feeding device (999) according to claim 3, wherein the first transmission portion (15) and the second transmission portion (16) comprise a respective first input shaft (17) and second input shaft (18) and a respective first output shaft (19) and second output shaft (20), wherein the first input shaft (17) and the second input shaft (18) are mechanically connected to the first motor shaft (12) and the second motor shaft (13), respectively, for rotation with the first motor shaft (12) and the second motor shaft (13), wherein the first output shaft (19) and the second output shaft (20) are mechanically connected to the first roller (1) and the second roller (2), respectively, for rotation of the first roller (1) and the second roller (2).

5. The feeding device (999) according to claim 4, wherein each of the first transmission portion (15) and the second transmission portion (16) comprises a mechanical coupling between the respective input shaft (17, 18) and the respective output shaft (19, 20) for transmitting rotation of the respective input shaft (17, 18) to the respective output shaft (19, 20) so as to limit or prevent rotation of the respective output shaft (19, 20) transmitted by non-respective input shafts (17, 18), and wherein the mechanical coupling comprises a worm gear type gear coupling arranged successively from the respective input shaft (17, 18) to the respective output shaft (19, 20).

6. The feeding device (999) according to any one of claims 3 to 5, wherein the transmission (14) is free of clutch members, and wherein each of the first transmission portion (15) and the second transmission portion (16) comprises a respective gearbox.

7. The feeding device (999) according to any one of claims 1 to 5, wherein each of the first roller (1) and the second roller (2) comprises a respective side surface (4), the side surfaces (4) being stretched in a cylindrically symmetrical manner about the respective rotation axis (101, 102), wherein the side surfaces (4) have a cylindrically stretched, wherein the side surfaces (4) are configured for gripping the continuous elongated element, and wherein the side surfaces (4) have a surface treatment for increasing the coefficient of friction with the continuous elongated element.

8. The feeding device (999) according to any one of claims 1 to 5, wherein the first roller (1) is movable along the displacement direction (103) by a length of greater than or equal to 5mm and/or less than or equal to 30mm, and wherein by virtue of the movement of the first roller (1) the minimum distance between the side surfaces (4) of the first roller (1) and the second roller (2) is greater than or equal to 2mm, the maximum distance is less than or equal to 40mm.

9. Feeding device (999) according to any one of claims 1 to 5, wherein the feeding device comprises a base body (21) extending along a longitudinal direction (201), a transverse direction (202) and a height (203), respectively, wherein the first roller (1) is movable relative to the base body (21), wherein the base body (21) comprises a first seat (22) and a second seat (23) which accommodate the first roller (1) and the second roller (2), respectively, at least partially, wherein the base body (21) comprises a through hole (24) having an inlet mouth (25) and an outlet mouth (26) arranged along the height (203) on opposite sides of the base body (21), wherein the through hole (24) is interposed between the first seat (22) and the second seat (23), wherein the first seat (22) and the second seat (23) are in communication with the through hole (24), wherein the first roller (1) and the second roller (2) can only partially block the through hole (24) and wherein the through hole (2) is accessible to the surface of the first roller (2).

10. The feeding device (999) according to claim 9, wherein the base (21) comprises a set of base elements (31) which can be assembled together to form the base (21), wherein the base elements (31) have a main plane extending along the longitudinal direction (201) and the transverse direction (202) and they are stacked along the height (203), wherein the set of base elements comprises at least three base elements, wherein one or more base elements (31) comprises a respective recess shaped for forming the first seat (22) and the second seat (23) together with the base elements (31) assembled together to form the base (21), and wherein the length (L) of the inlet mouth (25) of the through hole (24) along the longitudinal direction (201) is greater than or equal to 20cm, and/or less than or equal to 150cm.

11. The feeding device (999) according to claim 4, wherein the first input shaft (17) and the second input shaft (18) are rigidly connected to the first motor shaft (12) and the second motor shaft (13), respectively, to rotate integrally with the first motor shaft (12) and the second motor shaft (13).

12. The feeding device (999) according to claim 4, wherein the first output shaft (19) and the second output shaft (20) are rigidly connected to the first roller (1) and the second roller (2) respectively for rotating the first roller (1) and the second roller (2).

13. The feeding device (999) according to claim 9, wherein said first seat (22) and said second seat (23) are contiguous to said through hole (24).

14. The feeding device (999) according to claim 6, wherein each of the first transmission portion (15) and the second transmission portion (16) is free of clutch members.

15. A feeding device (99) of a continuous elongated element (900), the feeding device comprising an advancing system (91) for advancing the continuous elongated element in an advancing direction (100) along a first passage (110), the advancing system (91) comprising a feeding means (999) according to any one of claims 1 to 14, the feeding means being provided at an outlet of the first passage (110) for continuously feeding the continuous elongated element at a feeding speed to a feeding point (a) corresponding to the outlet of the first passage (110), wherein the feeding device (99) comprises a measuring system (92) for continuously measuring on the continuous elongated element an amount suitable for evaluating an actual flow rate of the continuous elongated element continuously fed to the feeding point (a), wherein the feeding device (99) comprises a command and control unit (93) connected to the advancing system (91) and to the measuring system (92) and programmed for continuously commanding the feeding of the continuous elongated element at the feeding point (91) to an adjusted value of the feeding rate of the continuous elongated element according to the feeding speed of the continuous feeding system (91).

16. The feeding apparatus (99) according to claim 15, wherein the quantity comprises geometrical information sufficient for calculating, at least in an approximate way, a value representative of an area range of a section (200) of the continuous elongated element (900) on a plane substantially perpendicular to the advancing direction (100), and wherein the measuring system (92) comprises optical detection means (94) for continuously detecting the geometrical information in detection points (R) along the first path (110).

17. The feeding apparatus (99) according to claim 16, wherein the geometrical information comprises a height distribution of at least a portion of the profile of the cross-section (200) with respect to a reference height, and wherein the optical detection device (94) comprises a matrix camera having an optical axis (300) and a linear laser source capable of emitting a linear laser beam (301) having a propagation axis.

18. The feeding device (99) according to claim 16 or 17, wherein the command and control unit (93) is programmed for continuously calculating a value representing an area range of the cross-section (200) from the geometrical information and for continuously calculating a theoretical value of the feeding speed from a ratio between the reference value of the feeding flow rate and a value representing an area range of the cross-section (200), wherein continuously adjusting the feeding speed comprises setting the feeding speed equal to the theoretical value, wherein continuously commanding the advancing system (91) for continuously adjusting the feeding speed comprises continuously commanding the feeding means (999), and wherein the command and control unit (93) is programmed for calculating a time delay taken by the cross-section (200) to travel from the detection point (R) to the feeding point (a) and for continuously commanding the advancing system (91) for continuously adjusting the feeding speed from the time delay.

19. An apparatus (90) comprising a feeding device (999) according to any one of claims 1 to 14 and a continuous processing machine (80), the continuous processing machine (80) comprising a feed screw (81) with a respective rotation axis (105), wherein the feeding device (999) is arranged in proximity of the feed screw (81), and wherein the continuous processing machine (80) is one of: planetary extruder, twin-screw mixer, annular extruder, single-screw extruder, twin-screw extruder, feed extruder for textile gumming calender, extruder for semifinished product.

20. A method for feeding a continuous elongated element (900), the method comprising:

-providing a first roller (1) and a second roller (2) arranged side by side, the respective axes of rotation (101, 102) of the first and second rollers being substantially parallel to each other, wherein the first roller (1) is movable relative to the second roller (2) along a displacement direction (103) in order to vary a mutual distance (D) between the axes of rotation (101, 102);

-arranging the continuous elongated element between the first roller (1) and the second roller (2);

-pushing the first roller (1) towards the second roller (2) with an adjustable pushing force so as to clamp the continuous elongated element (900) between the first roller (1) and the second roller (2);

Rotating the first roller (1) and the second roller (2) so as to advance the continuous elongated element (900) to continuously feed the continuous elongated element (900) to a feed point (A) at a feed speed,

-controlling the respective rotational speeds of the first roller (1) and the second roller (2) so as to limit or prevent a variation of the respective rotational speeds due to an action exerted by the continuous elongated element (900) on at least one of the first roller (1) and the second roller (2).

21. A tyre production process comprising a method for feeding a continuous elongated element according to claim 20.