Patent Publication Number: US-11390479-B2

Title: Unwinder for rolls of paper and similar

Description:
TECHNICAL FIELD 
     The present invention relates to improvements to unwinders for unwinding rolls of web material, such as rolls of paper or similar. 
     BACKGROUND ART 
     In many industrial sectors it is necessary to unwind rolls of web material to feed one or more continuous strips or sheets to a processing line. Typically, rolls of paper are used to feed lines for the production of corrugated board. For this purpose, unwinders are used that support one or more rolls of web material, which are put to work sequentially. To allow the production line to operate continuously, the unwinders usually have two pairs of roll-support arms, to support a working roll and a roll in standby. A splicing machine, usually mounted on a structure overhanging the un-winder, automatically joins the tail of the web material unwound from the working roll with the head of the web material wound around the roll in standby. 
     Examples of unwinders, particularly useful for feeding paper to corrugated board production lines are disclosed in U.S. Pat. Nos. 6,966,961; 7,441,579; US2017/0291784; U.S. Pat. No. 8,011,409; EP0341642; U.S. Pat. No. 6,786,264; EP1348658. These unwinders are also fitted with splicing machines, i.e. with devices whose job is to join the tail of a first web material with the head of a second web material. 
     The transport and installation of these machines on the production line are long, complex operations, requiring considerable specialist labor. The splicing machine and the unwinder are usually transported separately. The splicing machine and the unwinder are then installed, wired and tested before being able to start up the production line. Typically, there is a bearing structure with uprights and cross members, to which the splicing machine is applied. To do so, specific lifting members are provided to raise the splicing machine up to the height of the cross members of the bearing structure. Then, when the splicing machine has been anchored to the bearing structure and the lifting members have been disassembled and removed, sufficient space is created to install the unwinder under the splicing machine. Once this double installation has been completed, all mechanical, electrical and pneumatic connections need to be made. Lastly, the unwinder/splicing machine assembly needs to be tested. 
     These operations are long and complex. 
     It would be beneficial, both for the machine manufacturer, and for the user, to have systems adapted to simplify, facilitate and speed up these operations, thereby also reducing the amount of specialist labor required to carry them out. 
     SUMMARY 
     A roll unwinder comprising a bearing structure and two pairs of arms supported movable on the bearing structure is provided. Each arm comprises members for axial engagement of a roll, for example tailstocks. The unwinder also comprises a splicing machine. Advantageously, the splicing machine is integrated in the bearing structure of the unwinder, so as to be supported by it. In particular, the bearing structure may advantageously comprise a base and an upright extending from the base, on which a cross member is supported. The cross member comprises an intermediate portion rigidly bound to the upright and a pair of articulated lateral supports, adapted to take at least one operating position and one non-operating position, with respect to the intermediate portion of the cross member. 
     In this way, the unwinder becomes an integrated machine, to the bearing structure of which are fixed both the support and manipulation arms for the rolls to be unwound, and the splicing machine. The cross member, divided into three portions, can be folded into a position taking a minimal amount of space, for example for transport. 
     This thereby offers the possibility of assembling the entire unwinder, including the splicing machine, while also making the electrical, hydraulic and pneumatic connections between the various components, if required. The entire unwinder can thus be assembled and tested by the manufacturer before shipping to the end customer. After assembly, connection and testing, without dismantling important portions of the unwinder, but possibly only some secondary components, the cross member can be folded into a position taking a minimal amount of space, in order to facilitate transportation of the machine to the place where it will be used. Here, performing the operations in reverse, the cross member is extended into the operating position and, without the need for external bearing structures or lifting members, the unwinder with the integrated splicing machine is installed by means of simple, quick operations that do not require any particular technical expertise. 
     Furthermore, since the main components of the unwinder have been assembled, wired and tested, and not dismantled or disconnected afterwards, the unwinder does not need to be subjected to a further testing phase. 
     In embodiments described here, the splicing machine is supported by the cross member and comprises parts movable along said cross member. 
     In advantageous embodiments, in the operating position, the lateral supports of the cross member are aligned with the intermediate portion. Conversely, in the non-operating position, the lateral supports are turned towards the base of the bearing structure of the unwinder, in a position taking a minimal amount of space. 
     The arms of each pair of arms are connected to the bearing structure around a respective rotation axis. Preferably, there are two rotation axes parallel to one another, one for each pair of arms. When the unwinder is in the working position, the axes are substantially horizontal. 
     In advantageous embodiments, the arms are carried by slides movable on beams pivoting around the rotation axes and supported by the base of the bearing structure of the unwinder. In this way, the arms of each pair of arms can be movable, with respect to the bearing structure, in a direction parallel to the rotation axes. 
     The lateral supports of the cross member can advantageously be hinged to the upright, or to the intermediate portion of the cross member, around axes parallel to the rotation axes of the arms. The lateral supports can have a rotation movement, or a combined rotary-translation movement, with respect to the central portion of the cross member and/or with respect to the upright of the bearing structure. In other embodiments, the lateral supports may have a translation-only movement, for example in a telescopic configuration. 
     Further advantageous features and embodiments of the unwinder according to the invention are described below and defined in the accompanying claims, which form an integral part of the present description. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention will be better understood by following the description and accompanying drawings, which illustrate by way of example a non-limiting embodiment of the invention. Specifically, with reference to the drawings: 
         FIG. 1  shows a front view of an unwinder with relative integrated splicing machine, in a folded position; 
         FIG. 2  shows a side view along the line II-II of  FIG. 1 ; 
         FIG. 3  shows a front view similar to the view shown in  FIG. 1 , in the working position; 
         FIG. 4  shows a side view along the line IV-IV of  FIG. 3 ; 
         FIG. 5  shows a simplified view, along a mid-line plane V-V of  FIG. 2 ; 
         FIG. 6  shows a simplified view, along a mid-line plane VI-VI of  FIG. 3 ; 
         FIGS. 7, 8, 9, 10, 11, 12  show a sequence of splicing and replacement of working rolls in a cross-section similar to  FIG. 6 . 
     
    
    
     DETAILED DESCRIPTION 
     An unwinder with a respective integrated splicing machine according to embodiments of the invention is shown in  FIGS. 1, 2, 3, 4, 5 and 6 . In  FIGS. 1, 2 and 5  the unwinder and the respective integrated splicing machine are in a folded position, while in  FIGS. 3, 4 and 6  the unwinder and the respective splicing machine are in the working position. 
     The unwinder  1  comprises a bearing structure  3  with a base  5  and an upright  7 . The bearing structure  3  is configured to support a first pair of arms  11 A,  11 B and a second pair of arms  13 A,  13 B. The arms  11 A,  11 B;  13 A,  13 B are adapted to engage with rolls B 1 , B 2  of web material ( FIGS. 7-12 , described below) to be unwound in order to feed the web material to a production line (not shown), such as, for example, a corrugated board production line. Each arm  11 A,  11 B,  13 A,  13 B is fitted with tailstocks or other axial engagement members  17 , for engaging the rolls B 1 , B 2 . The arms of each pair of arms  11 A,  11 B and  13 A,  13 B, respectively, are hinged to the bearing structure  3  so as to rotate around respective rotation axes X 1  and X 2 , parallel to one another and horizontal, when the unwinder is in operating conditions. To that end, the arms of each pair are mounted on respective beams, indicated by reference number  21 , hinged to the bearing structure  3  around the rotation axes X 1 , X 2 . Each arm  11 A,  11 B,  13 A,  13 B can slide, for example by means of a slide  19  ( FIGS. 1 and 3 ) movable along guides  22  integral with the respective beam  21 , such that the mutual distance between the arms  11 A,  11 B or  13 A,  13 B of each pair can be adjusted. This makes it possible, in a known manner, to use the arms  11 A,  11 B;  13 A,  13 B to engage rolls B 1 , B 2  with different axial dimensions. In  FIGS. 1 and 3  the double arrow f 13  indicates the movement for adjusting the mutual distance between the arms  13 A,  13 B. 
     The rotation around the axes X 1 , X 2  enables the arms  11 A,  11 B;  13 A,  13 B to take two positions—maximum raised position ( FIGS. 1, 2 ) and maximum lowered position ( FIGS. 3 and 4 )—as well as intermediate positions between these two extreme positions. The double arrows F 11 , F 13  in  FIG. 4  show the raising and lowering movement of the arms  11 A,  11 B and  13 A,  13 B by means of rotation around the axes X 1  and X 2 . The translation and rotation movement of the arms  11 A,  11 B;  13 A,  13 B is controlled in a known manner by suitable actuators, not described in detail. 
     Characteristically, the bearing structure  3  of the unwinder  1  is configured so as to support, in addition to the arms  11 A,  11 B,  13 A,  13 B and the respective movement members, also a splicing machine, indicated as a whole by reference number  31  (see  FIG. 5 ). More specifically, in order to support the splicing machine  31 , the bearing structure  3  comprises a cross member  33 , in one piece with the upright  7 . As can be understood from  FIGS. 1 and 3 , the upright  7  is a double upright, and in the same way the cross member  33  is a double cross member, with a structure approximately symmetrical with respect to a vertical mid-plane of the unwinder, orthogonal to the axes X 1 , X 2 . Between the two portions of the cross member  33  and the upright  7  there are positioned the members forming the splicing machine  31 , as well as idler rollers for the web materials that are unwound from the rolls placed in the unwinder  1 , as described below. 
     The cross member  33  is divided into three portions. A first central or intermediate portion, indicated by the reference number  33 A, is rigidly connected to the upright  7 . Two lateral extension portions  33 B,  33 C of the cross member are bound to the intermediate portion, wherein the lateral extension portions constitute lateral supports for members of the splicing machine  31 , as will be clarified below. In the embodiment shown, the lateral portions or lateral supports  33 B,  33 C are hinged to the intermediate portion  33 A so as to rotate around axes that may advantageously be parallel to the rotation axes X 1 , X 2  of the arms  11 A,  11 B,  13 A,  13 B. In the embodiment shown, the two lateral supports  33 B,  33 C are hinged to the intermediate portion  33 A of the cross member  33 , for example around axes  37  and  39 , respectively. The references f 33 A and f 33 B are used in  FIGS. 2, 4, 5 and 6  to indicate the rotation movements by which the lateral supports  33 B and  33 C can be brought from a folded, non-operating position, shown in  FIGS. 1, 2, and 5 , to an operating position, shown in the remaining  FIGS. 3, 4, 6-12 . 
     The folded position shown in  FIGS. 1, 2, 5  is a transport position, in which the unwinder  1  takes a position requiring a minimal amount of space so that it can be housed in a container, for example. The operating position is that taken by the unwinder when it is in operation. In the folded position ( FIGS. 1, 2, 5 ) the arms  11 A,  11 B,  13 A,  13 B are in a raised position, so as to reduce the amount of space they take up. In practice, the arms are found within the volume defined by the upright  7  and do not protrude beyond the folded lateral supports  33 B,  33 C. 
     As will become clear from the following description, the passage from the folded position ( FIGS. 1, 2, 5 ) to the operating position does not require anything other than the rotation of the lateral supports  33 B,  33 C and possibly some other minor operations that are quick and easy to perform. 
     With a structure of this type it is possible to fully assemble the unwinder  1  in the factory, completing wiring (electrical connections) and hydraulic and/or pneumatic connections. It is therefore also possible to conduct functional tests on the unwinder before shipping it to the place where it will be used. 
     Since the unwinder does not need to be disassembled for shipping, given that it is sufficient to fold it from the working position ( FIGS. 3, 4, 6-12 ) to the non-operating or folded position ( FIGS. 1, 2, 5 ), when the unwinder is installed on the production line, the parts thereof are already connected and wired. In particular, the splicing machine is already connected to the remaining parts of the unwinder, including the possible on-board computer. There is no need, therefore, to repeat testing operations or other lengthy and complex operations. There is also no need to provide an external bearing structure for the splicing machine to be applied to, and under which to position the unwinder. This is because the unwinder is fitted with its own bearing structure onto which the splicing machine  31  is mounted. 
     The entire installation process is therefore very fast and can be performed by a small number of personnel, and also by personnel without any particular skill. 
     As can be seen in particular in  FIGS. 6 to 12 , on the cross member  31  there are provided various components of the splicing machine  31 , some of which may be fixed while others are movable. More specifically, in the embodiment shown, the splicing machine  31  comprises a pair of intermediate rollers  41 ,  43 , arranged on a central operating unit or assembly  45  in a fixed position on the intermediate portion  33 A of the cross member  33 . The central operating unit or assembly  45  with the two intermediate rollers  41 ,  43  co-acts with two movable assemblies  47 A,  47 B of the splicing machine  41 . Operation of the components  41 - 47  is substantially the same as that for the splicing machine disclosed in U.S. Pat. No. 7,441,579, the content whereof is incorporated herein, and therefore will not be described in detail, but referenced briefly in the sequence of  FIGS. 7 to 12 , from which the differences compared to the operation of splicing machines of the prior art will become clear, said differences mainly concerning the distribution of movements between the various components of the splicing machine. 
     As can be seen in particular in  FIGS. 5 to 12 , the two movable assemblies  47 A,  47 B of the splicing machine  31  are mounted on a carriage  51  provided with a translation movement along the cross member  33 , in order to perform the various phases of splicing between web materials coming from rolls supported by the pairs of arms  11 A,  11 B and  13 A,  13 B. The carriage  51  is movable along guides  53 , at least one of which can be associated with a rack, with engages with the pinion of a motor (not shown), controlling the translation movement of the carriage  51  along the cross member  33 . 
     The guides  53  can be removed from the cross member  33  when it is in the folded position ( FIG. 5 ) and can be fitted onto the cross member  33  when the lateral portions, forming the lateral supports  33 B,  33 C, are aligned with the intermediate portion  33 A ( FIGS. 6-12 ). Fitting and removing the guides and/or racks  53  is a quick and simple operation, which does not require any interventions on the wiring or other connecting elements between parts of the splicing machine  31  and other components of the unwinder  1 . 
     In some embodiments, an idler roller  54  is also supported on the carriage  51 , to guide a web material in certain operating conditions. 
     A slide  55  is also movable along the cross member  33 , which carries one or more idler rollers for the web material. In the embodiment shown, the slide  55  carries a first idler roller  57  and a second idler roller  59 . The slide  55  can translate along the cross member  33  in a direction f 55  parallel to the cross member  55  and therefore orthogonal to the rotation axes X 1  and X 2  of the arms  11 A,  11 B and  13 A,  13 B. The movement of the slide  55  along the cross member  33  can be controlled by a suitable actuator, for example an electric motor  61 , which causes a pinion (not shown) to rotate and engage with a rack. The rack can be associated with guides  63  extending along the cross member  33 . Like the guides  53 , the guides  63  and relative rack can also be removed when the unwinder  1  is in a non-operating position ( FIGS. 1, 2, 5 ) and can be fitted when the cross member  33  is extended with the portions  33 A,  33 B,  33 C aligned and in an operating position ( FIGS. 3, 4, 6-12 ) 
     The idler rollers  57  and  59 , movable along the cross member  33 , co-act with two idler rollers  62 ,  64  fixed to the cross member  33 , to form a stock of web material, so as to allow splicing operations between a web material coming from a roll that is nearly empty (or being replaced) and a web material from a roll standing-by, as will be clarified below with reference to a splicing cycle illustrated in the sequence of  FIGS. 7 to 12 . 
     Having described the basic components of the unwinder  1 , with reference to  FIGS. 1, 2, 5  and  FIGS. 3, 4, 6 , the operations that are performed to bring the unwinder  1  from the non-operating condition to the operating condition will now be illustrated. In  FIGS. 1, 2, 5  the arms  11 A,  11 B,  13 A,  13 B are turned upwards so as to occupy the minimum space possible, substantially next to the upright  7  or at least partially inside it. In this position the lateral portions of the cross member  33 , forming the lateral supports  33 B,  33 C, can be folded downwards thereby minimizing the size of the unwinder  1 . The guides and the racks for the carriage  51  and for the slide  55  can be at least in part removed from the machine, and in particular the portions that are coupled to the lateral supports  33 B,  33 C can be separated. The carriage  51  is in an intermediate position, and is supported by a portion of the guide  53  which remains in one piece with the central or intermediate portion  33 A of the cross member  33 . The slide  55  can also be supported on the central portion  33 A of the cross member  33 , or it can be removed. In the example shown, the slide  55  has been removed. 
     The unwinder  1  is brought from the folded condition shown in  FIGS. 1, 2, 5  to the operating position by means of the following simple operations. The lateral portions of the cross member  33 , which form the lateral supports  33 B,  33 C, are rotated upwards according to arrows f 33 B f 33 C ( FIGS. 2, 4 ) and fixed in a horizontal position, aligned with the intermediate portion  33 A of the cross member  33 . The guides and racks  53 ,  63 , or portions thereof, that may have been removed from the unwinder  1 , can be mounted to obtain the configuration shown in  FIGS. 6-12 .  FIG. 4  shows a situation in which the racks and guides are still removed. The reference numbers  67 ,  69  indicate ( FIGS. 2, 4, 5 ) through-holes or slots for fastening organs of the guides and racks for the carriage  51  and for the slide  55 . 
     In  FIG. 6  the arms  11 A,  11 B,  13 A,  13 B are still raised. They are then lowered to manipulate the rolls B 1 , B 2  as described below. 
       FIGS. 7 to 13  show an operating cycle of the splicing machine of the unwinder  1 . 
     In  FIG. 7  the roll B 1  is working and rotates (arrow fB 1  to unwind the web material N 1  and feed it to a production line (not shown). The roll B 1  is engaged by the arms  13 A, 13 B, which hold it raised from the ground to allow rotation thereof, for example by traction. The web material N 1  is guided around a roller  48 B of the movable assembly  47 B, around the intermediate roller  43 , around the fixed idler rollers  62 ,  64 , and around the movable idler rollers  57 ,  59 , to provide a stock of web material N 1 . 
     A second roll B 2  of web material has been inserted into the unwinder  1  and is resting on the ground, for example on a conveyor belt  81 , to be engaged by the arms  11 A,  11 B temporarily in a non-operating position. 
       FIG. 8  shows a subsequent phase, in which the roll B 1  has been partially unwound, while the head of a web material N 2  wound on roll B 2  has been prepared and is held by the movable assembly  47 A. The roll B 2  has been engaged by the arms  11 A,  11 B and is raised with respect to the conveyor  81 , to allow rotation thereof. 
     In  FIG. 9  the movable assembly  47 B of the splicing machine  31  has moved from the central position to a lateral position, on the lateral support  33 B of the cross member  33 . The central portion  33 A of the cross member  33  is therefore free to allow the translation of the movable assembly  47 A to the central position. In this position, with a known operating sequence (see e.g. U.S. Pat. No. 7,441,579) the head of the web material N 2  is spliced to a tail of the material N 1 , which is generated by cutting the web material delivered by the roll B 1 . 
     Once the material N 2  has been spliced to the material N 1 , the roll B 2  begins to rotate delivering the web material N 2 , while the roll B 1  can stop. This phase is shown in  FIG. 10 . Reference fB 2  is used to indicate the direction of rotation of the unwinding roll B 2 . The splicing phase of the web materials N 1 , N 2 , which is performed between  FIG. 9  and  FIG. 10  requires a temporary stoppage or slowing down of the web material N 1 , N 2 . To prevent impacts downstream on the production line, during this phase the stock of web material N 1  formed between the rollers  48 B,  43 ,  64 ,  57 ,  62 ,  59  is used. This is made possible by the translation of the movable guide rollers  57 ,  59  from the position shown in  FIG. 9  (on the right-hand support  33 C) to the position shown in  FIG. 10  (on the left-hand support  33 B). 
     Subsequently ( FIG. 11 ) the stock of web material N 2  is restored, by translating from left to right the slide  55  with the movable idler rollers  57 ,  59 , which return to the left-hand support  33 C. In  FIG. 11  the roll B 1  has been lowered by the arms  13 A,  13 B and, for example, released onto a conveyor  82 , similar to the conveyor  81 . 
     The roll B 1  can be removed from the unwinder ( FIG. 12 ) to be replaced by another roll for the next cycle. 
     As can be seen from the sequence of  FIGS. 7 to 12 , the roll B 2  is replaced by the roll B 1  when the latter is not yet exhausted. This is because replacement of one roll with another can be done for various reasons, and not only when the roll is exhausted. For example, the roll B 1  may be replaced if the web material N 1  breaks, or if the production line downstream requires the replacement of one type of material (N 1 , roll B 1 ) with another (N 2 , roll B 2 ).