TRANSFER DEVICE PARTICULARLY FOR FLEXIBLE LAMINAR PRODUCTS

Abstract: A transfer device, particularly for flexible laminar products, includes a belt (2) of preset length, the ends (3, 4) whereof are anchored and partially wound around two oppositely arranged main rollers (5, 6); a motor (9) which acts on the main rollers (5, 6) to wind and respectively unwind, with controlled torques, the ends of the belt, keeping it constantly stretched, as well as a ramp (12) for depositing one or more products (P) onto the surface of the belt (7) which is directed toward the takeup roller, so as to convey the products toward this roller and retain them between this roller and the wound belt portion. The main rollers (5, 6) have identical tangential peripheral speeds with continuously opposite rotation directions. The motor (9) includes, for each of the main rollers (5, 6), a servomotor with torque control which is controlled by an intelligent controller (11) which is programmed so that at all times the torque which acts on the takeup roller is greater than the torque which acts on the unwinding roller.

Description: TRANSFER DEVICE PARTICULARLY FOR FLEXIBLE LAMINAR PRODUCTS The present invention relates to a device for the transf * v of flexible laminar products having various dimensions and shapes and in different chemical and physical conditions. The device can be used in the fields of paper-making, textiles, food, tanning, plastics and the like. For examp *, in order to handle wet or moist sheets of paper or the like, these sheets must be laid on drying tables to dry them completely. In other cases, the semifinished or finished products must be stacked in an orderly manner to transfer them from one area to another of the factory or to be packaged, It is known that these products, especially if wet or moist or irregularly shaped, are normally handled manually in order to ensure their appropriate laying, with a considerable wasio of time and labor. On the other hand, known mechanical handling units do not allow to automate all the steps performed, and most of all do not ensure optimum and crease-free laying of the products, especially in conditions of high humidity, with a high risk of irreversible damage and of production rejects. The aim of the present invention is to eliminate or at least limit the drawbacks described above by providing a device for transferring and laying on appropriate supporting surfaces flexible laminar products which allows to fully automate the loading and unloading of the products, ensuring their SUBSTITUTESHEET appropriate laying on working or stacking surfaces. An object of the invention is to provide a transfer device which has a relatively simple and reliable structure so that it is economically advantageous. Another object of the invention is to provide a device which is simple to use and maintain so that it is within the capabilities of any operator, including non-expert ones. This aim and these objects are achieved by a transfer device, particularly for flexible laminar products, characterized in that it includes a belt of preset length and having ends anchored and partially wound around a pair of oppositely arranged main rollers, a motor means being provided which acts on the rollers to wind and respectively unwind, with controlled torques, the ends of the belt, keeping it constantly stretched, as well as a means for depositing ι. ,ιu or more products onto the surface of the belt which is directed toward the takeup roller, so as to convey the products toward this roller and retain them between this roller and the wound belt portion. The device according to the invention allows to obtain the optimum laying of the products prior to their conveyance into the channel formed between the takeup roller and the wound belt portion, avoiding corrugation, creasing and laminar deformation of the products. Further characteristics and advantages of the present. SUBSTITUTESHEET invention will become apparent from the detailed description of an embodiment, illustrated by way of non-limitative example in the accompanying drawing, wherein: Figure 1 is a schematic view of a device according to the invention in a first operating step; Figure 2 is a partial view of the device of Figure 1 in ,ι second operating step. With reference to the above figures, the device according to the invention, generally designated by the reference numera L 1, includes a belt 2 made of flexible material having a selected length which is greater than the maximum dimension of the products to be transferred. The longitudinal ends 3 and 4 of the belt are fixed to a pair of rollers 5 and 6. The belt 2 has opposite surfaces 7 and 8 and end portions which are partially wound in opposite directions on the rollers Li and 6, so that the surface 7 is in contact with the roller 5 and the surface 8 is in contact with the roller 6. The rollers 5 and 6 are coupled, by means of appropriate reduction units not shown in the drawings, to respective servomotors 9 and 10 which are powered electronically and are controlled by an intelligent electronic controller 11, for example a PLC. The intelligent controller 11 controls the speed and torque of the servomotors 9 and 10 so that the rollers 5 and 6 have, at all times, identical peripheral speeds and continuously opposite rotation directions, so as to operate selectively as SUBSTITUTESHEET takeup and unwinding rollers according to the situation. Conveniently, according to the invention, the controller 11 is programmed to also control the value of the torques of the servomotors 9 and 10, so as to keep the belt 2 constantly stretched with a force having a preset value which can b adjusted according to the requirements and to the type of product to be handled. Thus, it is possible to lay on the surface 7 of the belt one or more products P starting from an adapted loading means, constituted for example by a simple ramp 12 or by an external conveyor belt which is arranged above the rolJer 6 and is not shown in the drawings. The axis 13 of the roller 5 is fixed, whereas the axis 14 of the roller 6 is movable in order to allow the operations for loading and unloading the products P, as described hereinafter. In particular, the axis 14 is rotatably supported at the end of a frame 15 which is in turn pivoted, with its opposite end, to a fixed axis 16 which is paralliJ to the axis of the roller 14. The frame 15 can be coupled to an actuator 17 which is adapted to make it oscillate between a first extreme position, to the left as shown in Figure 1, in which the roller 6 is at its maximum distance from the roller 5, and a second extreme position, to the right in Figure 2, in which the roller 6 is at its minimum distance from the roller 5. In the first position, the roller 5 rotates counterclockwise and takes up the corresponding end of the belt, whereas the roller 6 rotates clockwise and unwinds the opposite end of SUBSTITUTESHEET the belt 2 , so that the belt moves from right to left and is constantly kept stretched by virtue of the balanced torqiυ u of the servomotors 9 and 10. In this situation, the products P. loaded onto the belt are transferred toward the takeup roller 5 and are elastically retained and temporarily stored in the interspace formed between the internal surface of the belt 7 and the outer wall of the roller 5. Conveniently, adjacent to the roller 5 there is a secondaι.y roller 18 which is freely mounted on a fixed axis 19 and forms a supporting and guiding surface for the belt 2. Furthermore, in order to avoid corrugation, creasing and laminar deformation directly ahead of the region where the belt winds onto the roller 5, there is a further secondary roller 20, optionally with a surface which forms spirals with multiple starts in opposite directions starting from its centerline. The roller 20 is coupled to a servomotor 21 which gives it a tangential peripheral speed equal to the belt advancement speed, and may be elastically compressed with a calibrated force against the surface 7 of the belt so as to perform the double function of perfectly laying out the laminar products P and of expelling any humid residues prior to their temporary storage. Advantageously, the rollers 5, 6, 18 and 20 are mounted on a supporting structure, not shown in the drawings, so as to form as a whole a unit which can move longitudinally and parallel to the supporting or unloading surface S, whi. li belongs to a stacking table or to a subsequent machine. SUBSTITUTE SHEET In Figure 2, the device is shown during the unloading step, in which the frame 15 is in its second extreme position. In this step, the rollers 5 and 6 reverse their rotation direction with respect to the preceding step, whereas the axis of the roller 6 is moved into the position in which it is closest to the roller 5. The belt thus advances in the opposite direction, from right to left, moving the perfectly laid out products toward the unloading surface S. At the same time, the moving unit moves to the left or to the right at the same speed with which the belt unwinds, so as to deposit the products P onto the surface S. The operation of the device is substantially evident. On<.υ the rollers 5 and 6 have been started in the direction shown in Figure 1, the products P are deposited onto the belt, which conveys them toward the takeup roller 5, against which they are retained by the internal surface 7 of the belt. By reversing the rotation direction and moving the roller unit at the same speed with which the belt unwinds, the products P are unloaded onto the surface S for subsequent uses. The device according to the invention is susceptible to modifications and variations which are within the scope of the inventive concept expressed by the accompanying claims. Where technical features mentioned in any claim are followed by reference signs, those reference signs have been includ J for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the scope of each element identified by way of example by such reference signs. SUBSTITUTESHEET

Claims: CLAIMS 1. Transfer device, particularly for flexible laminar products, characterized in that it comprises a belt (2) ol; preset length and having ends (3, 4) anchored and partially wound around two oppositely arranged main rollers (5, 6), ι motor means (9, 10) being provided which acts on said rollers (5, 6) to wind and respectively unwind, with controlled torques, the ends of the belt, keeping it constantly stretched, as well as a means (12) for depositing one or rnoi υ products (P) onto the surface of the belt (7) which is directed toward the takeup roller, so as to convey t o products (P) toward said roller and retain them between said roller and the wound belt portion. 2. Transfer device according to claim 1, characterized in that said main rollers (5, 6) are substantially parallel and have identical tangential peripheral speeds with continuously opposite rotation directions. 3. Transfer device according to claim 1, characterized in that one of said main rollers (5) has a fixed axis (13) and the other roller (6) has a movable axis (14) . 4. Transfer device according to claim 1, characterized in that the rotation axis (14) of the movable main roller is mounted on a frame (15) which is in turn pivoted about, m axis (16) which is substantially parallel to the rotation axis (14) of the roller (6) . 5. Transfer device according to claim 4, characterized in SUBSTITUTESHEET that said frame (16) can oscillate under control between a position in which it is more distant from the fixed main roller (5), in order to load the products onto the belt, and a position in which it is closer to the fixed main roller (5) , in order to unload the products by reversing the advancement direction of the belt (2) . 6. Transfer device according to claim 1, characterized in that, said motor means (9, 10) comprises, for each one of said main rollers (5, 6), a servomotor with torque control, controlled by an electronic intelligent controller (11) . 7. Transfer device according to claim 6, characterized in that said intelligent controller (12) is programmed so that at all times the torque which acts on the takeup roller is greater than the torque which acts on the unwinding roller. 8. Transfer device according to claim 1, characterized in that it furthermore has a free secondary roller (18) which iu interposed between the main takeup/unwinding rollers and forms a support for the belt (2) on the same side as i he movable main roller (6) . 9. Transfer device according to claim 1, characterized in that it has a further secondary roller (20) which is elastically compressed against the products (P) in order lo lay them out on the belt (2) prior to their insertion between the takeup roller and said belt, said roller (20) preferably having a spiral surface and being motorized (21) so as to rotate with controlled speed and torque. SUBSTITUTESHEET 10. Transfer device according to the preceding claims, characterized in that said main rollers (5, 6) and said secondary rollers (18, 20) constitute, as a whole, a movable unit which can move, at right angles to the axes of the rollers, by rolling on an underlying unloading surface (S) . SUBSTITUTESHEET

Inventors: CORNER ANTONIO, CORNER, ANTONIO
Applicants: CARTIGLIANO OFF SPA, CORNER ANTONIO, OFFICINE DI CARTIGLIANO S.P.A.
Application year: 1993
Main classification: B65H15
IPC codes: B65H5, B65H15, D21F13