Patent Publication Number: US-10328474-B2

Title: Combined device for bending and cutting ribbon-shaped elements and method for bending and cutting ribbon-shaped elements through such device

Description:
BACKGROUND OF THE INVENTION 
     1) Field of the Invention 
     The present invention refers to a combined device for bending and cutting ribbon-shaped elements. 
     In particular, the invention deals with a combined device for bending and cutting parts of dinking dies used in the paper sector starting from a ribbon-shaped element, typically made of metal, to obtain a profile. 
     2) Background Art 
     A completely manual process for making such profile first of all allows cutting a piece of ribbon, for a length corresponding to the development of the profile which has to be obtained, then bending it. 
     The same process can be performed by means of machines comprising a series of working stations, the main ones of which are the cutting and bending stations, and a dragging apparatus to move the ribbon therethrough. 
     Currently, the art substantially provides for two approaches to the performance of such actions. 
     A first method consists in completely cutting a piece of ribbon before bending it. Since such piece is completely cut, the passage through the bending station occurs by means of a guide along which such piece is pushed or by another piece cut afterwards or by the ribbon itself still to be cut, or also by a tool with a section similar to the ribbon&#39;s one. An example embodiment of such first method is disclosed in U.S. Pat. No. 5,787,750. 
     A second method consists in partially cutting, even not cutting at all, the piece to be made to be able to push such piece, still connected to the ribbon, into a bending station, and afterwards into a second cutting station adapted to definitively separate such piece from the ribbon. An example embodiment of such second method is disclosed in EP1264648. 
     As regards the bending station, a typical solution is disclosed in U.S. Pat. No. 4,627,255, which describes a bending machine, in which a metallic ribbon is bent during a sequence of longitudinal advancement steps of the ribbon alternated to flexure of the ribbon through a mobile tool which engages and deflects the ribbon when this later one is prevented from moving longitudinally. Such document then discloses feedback techniques to check the bending angle. 
     Such two method disclosed in U.S. Pat. No. 5,787,750 and EP1264648 allow making products with different features, such as bending angles, speed, guide, dummy pieces and costs. 
     Bending angles. The final cut of a piece performed after its bending often requires the widening of the bending angles, even over the actual mechanical limits of the bending station. In fact, the bent profile of the end of a ribbon could interfere with the device for the final cut. The problem is usually solved by limiting the opening of one or more angles in the bending step. 
     Speed. The final cut of the already bent end of a ribbon normally occurs in a more advanced position with respect to the bending station. This due to reasons linked to the sizes of the bending station and of the final cut. This often implies that, when creating pieces in a sequence, for some bending works on the following piece, the ribbon must be pushed back. These alternate front and back movements, which slows the execution, are not necessary for sequences of pieces of ribbon completely cut before their bending. 
     Guide and reference points. Handling of a completely cut piece of ribbon needs an efficient guide. Instead, for the end of a ribbon, it is enough to insert some mechanical bearing along the path. This is particularly advantageous when working rotary ribbons with a different diameter. 
     Dummy pieces. Completely cut pieces of ribbon having ends with profiles which cannot be paired for the thrust that cannot be put in a column. The problem is solved by cutting small dummy pieces which can guarantee the thrust. Instead, working the end of a ribbon does not need dummy pieces to guarantee the thrust. 
     Costs. Working of a completely cut piece of ribbon occurs with at least two stations, an initial cutting and a final bending station. Working of an end of a ribbon occurs with to least three stations, usually one for the initial partial cutting, one for bending and one for the final cutting. Under the same other conditions, the second method in general is much more costly that the first one. 
     A way to exploit and optimize the features of both these approaches consists in concentrating in the same station such bending and cutting actions. The current art already allows detaching a piece of ribbon by using the bending station, employing different alternate bending actions in order to be able to yield the material by acting on the same spot of the ribbon. But the biggest defect of this technique is given by the scarce quality obtained along such detachment line. Another problem of this technique depends on the slowness introduced by alternate bending movements. 
     SUMMARY OF THE INVENTION 
     Object of the present invention is providing a device capable of bending and cutting a ribbon-shaped element. 
     Another object is providing a device with limited needs of recurring to guides, capable of making bends next to the end and of not needing dummy pieces. 
     A further object is providing a device which does not need to widen the bends in order to make cutting tools pass therethrough and which is not slowed down by front-back ribbon movements. 
     A further object is providing a device with the bending and cutting actions in a combined way, which is compact and produced with reduced costs. 
     The above and other objects and advantages of the invention, as will appear from the following description, are obtained by a combined device for bending and cutting ribbon-shaped elements, as claimed in claim  1 . 
     Moreover, the above and other objects and advantages of the invention, as will appear from the following description, are obtained by a combined method for bending and cutting ribbon-shaped elements, as claimed herein. 
     Preferred embodiments and non-trivial variations of the present invention are the subject matter of the dependent claims. 
     It is intended that all enclosed claims form an integral part of the present description. 
     It will be immediately obvious that numerous variations and modifications (for example related to shape, sizes, arrangements and parts with equivalent functionality) could be made to what is described, without departing from the scope of the invention as appears from the enclosed claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be better described by some preferred embodiments thereof, provided as a non-limiting example, with reference to the enclosed drawings, in which: 
         FIGS. 1 and 2  show an axonometric view of an embodiment of the device according to the present invention; 
         FIG. 3  shows an axonometric exploded view of the embodiment of the device of the previous Figures; 
         FIG. 4  shows an axonometric view of a tool for bending and cutting belonging to an embodiment of the device according to the present invention; 
         FIG. 5  shows an enlarged view of a portion of the previous Figure; 
         FIGS. 6 and 7  show an orthogonal projection view of a tool for bending and cutting shown in the previous Figure; 
         FIG. 8  shows an axonometric view of a rotary template belonging to an embodiment of the device according to the present invention; 
         FIG. 9  shows a front view of the rotary template of the previous Figure; 
         FIG. 10  shows a side view of a fixed template with portion of profile for bending and for cutting, belonging to an embodiment of the device according to the present invention; 
         FIGS. 11 and 12  show an enlarged sectional view, respectively along line XI-XI and line XII-XII of the previous Figure; 
         FIGS. 13, 14, 16, 17 and 18  show axonometric views of the steps for bending and cutting ribbon-shaped elements, of an embodiment of the device according to the present invention; 
         FIGS. 15 and 19  show partially and enlarged sectional views of the fixed template and of the tool during the bending and cutting actions, of an embodiment of the device according to the present invention; 
         FIG. 20  shows an axonometric view of an embodiment of the device arranged for bending, in a version doubling the rotation means; 
         FIG. 21  shows an axonometric view of an embodiment of the device arranged for cutting, in a version doubling the rotation means according to the previous Figure; 
         FIG. 22  shows an axonometric and partially sectioned view of some components of an embodiment of the device, in a first variation of the version of the previous Figure; 
         FIG. 23  shows an axonometric view of some components of an embodiment of the device, in a second variation of the version of  FIG. 21 ; 
         FIG. 24  shows an exploded axonometric view of the elements of the previous Figure. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     With reference to  FIGS. 1 to 12, 20, 21 , it is possible to note that a combined device for bending and cutting ribbon-shaped elements comprises: first guiding and supporting means  1 ,  101  adapted to allow positioning at least one ribbon-shaped element T, T 1 ; second guiding and supporting means  3 ,  103  adapted to prevent the rotation of the ribbon-shaped element T, T 1  with respect to an axis belonging to the plane on which the ribbon-shaped element T, T 1  rests; first translating means  41 ,  1041  and rotation means  4 ,  104  adapted to move at least one tool  5 ,  105  with respect to the second guiding and supporting means  3 ,  103 . 
     Such second guiding and supporting means  3 ,  103  comprise at least one portion of bending profile  8 ,  108  adapted to bend the ribbon-shaped element T, T 1  and at least one portion of cutting profile  9 ,  109  adapted to cut the ribbon-shaped element T, T 1 . 
     The first translating means  41 ,  1041  allow aligning at least one portion of bending profile  10 ,  110  of the tool  5 ,  105  with the portion of bending profile  8 ,  108  of the second guiding and supporting means  3 ,  103  and at least one portion of cutting profile  11 ,  111  of the tool  5 ,  105  with the portion of cutting profile  9 ,  109  of the second guiding and supporting means  3 ,  103 . 
     A device according to the principles of the invention also comprises second translating means  6 ,  7 ,  12 ,  112  adapted to move the assembly of the second guiding and supporting means  3 ,  103  with the tool  5 ,  105  with respect to the first guiding and supporting means  1 ,  101 . 
     In this way, it is possible to move the aligned portions of profile, being them for bending  8 ,  108  with  10 ,  110 , and/or for cutting  9 ,  109  with  11 ,  111 , belonging to the second guiding and supporting means  3 ,  103  and to the tool  5 ,  105  respectively, so that such portions of profile can operate next to certain heights on the ribbon-shaped element T, T 1 . 
     Finally, the rotation means  4 ,  104  impose a rotation to the tool  5 ,  105  and therefore, since the ribbon-shaped element T, T 1  is prevented in its rotation by the second guiding and supporting means  3 ,  103 , allow cutting or bending the ribbon-shaped element T, T 1 . 
     According to a preferred configuration, the second guiding and supporting means  3 ,  103  are connected to a slider  12 ,  112  adapted to translate along guides  6 ,  7  with respect to the first guiding and supporting means  1 ,  101 . Moreover, the second guiding and supporting means  3 ,  103  comprise at least one slit  2 ,  102  adapted to be crossed by said at least one ribbon-shaped element T, T 1 . The slit  2 ,  102  comprises the portion of bending profile  8 ,  108  and the portion of cutting profile  9 ,  109  to be able to bend and cut the ribbon-shaped element T, T 1 . 
     The rotation means  4 ,  104  and the first translating means  41 ,  1041  belong to at least one rotary template equipped with a groove adapted to allow the tool  5 ,  105  to translate with respect to the rotary template, which can rotate with respect to an axis of the slider  12 ,  112 . 
     In a first configuration of the device, the rotation means  4  allow projectingly supporting the tool  5 . 
     If with the embodiment with projections excessive stresses are created on the tool, it is possible to use currently known solutions. For example, Japanese Patent 62-181835 deals with a bending device composed of two sections in which in each one two supports are present, which coaxially rotate in the same way, the element to be bent passes between such supports and the sliding tool of every section reaches and uses both rotary supports. Therefore, by exploiting the same technique, in a second configuration of the device shown in  FIGS. 20, 21 , a pair of rotation means  104  allows supporting the ends of the tool  105 . 
     In both configurations of the device, the translation of the tool  5 ,  105  with respect to the rotation means  4 ,  104  allows mating the bending or cutting profiles of the tool  5 ,  105  with those obtained along the slit  2 ,  102  of the second guiding and supporting means  3 ,  103 . 
     In particular, with the second configuration of the device, the pair of rotation means  104  is placed so that such ribbon-shaped element T 1  are approximately at the center between them and such rotation means  104  are connected through transmission members in order to perform the same angular displacements. 
     Object of such second configuration is guaranteeing a second support to such tool  105  in order to reduce its flexure during the bending and cutting actions. 
     Merely as an example,  FIG. 22  shows a possible version of the device in which the portions of profile for cutting and bending are associated with separate tools, two in this specific case. In the particular case, the tools slide in two rotary templates, but there could also be a single rotation element with different sliding tools. The view is limited to essential elements. 
     In the same way, merely as an example,  FIGS. 23 and 24  show a possible version of the device in which the tool have a null sliding, namely t is fastened to the rotation means. In this way, however, there could be problems to obtain bending and cutting on both sides of the ribbon-shaped element, to solve which the fixed tool is doubled. 
     From the kinematic point of view, therefore, there are at least three chances of movement:
         two secondary movements for arranging the bending or cutting action. Taking into account the meaningful elements, this is the sliding movement of the tool  5 ,  105  with respect to the second guiding and supporting means  3 ,  103  and of the movement of the assembly of the tool  5 ,  105  with the second guiding and supporting means  3 ,  103  with respect to the ribbon-shaped element T, T 1 ; in case of a non-sliding tool  5 ,  105 , only the second movement is possible;   a main movement, namely the rotation movement of such tool  5 ,  105  around the second guiding and supporting means  3 ,  103 ; such main movement performs the bending or cutting action.       

     Since the main movement is the one that usually needs most power, it is also the most encumbrant and costly one. Therefore, the structure of the invention composed as such, allowing to use a single movement member for both bending and cutting actions, is economic and compact. 
     With reference to  FIGS. 13 to 19 , a method for bending ribbon-shaped elements by means of an embodiment of such device comprises the following steps: 
     a—rotating the rotation means  4 ,  104  by a suitable angle Alfa 0  to allow the sliding of the ribbon-shaped element T, T 1  routed by the first guiding and supporting means  1 ,  101 , through and over the slit  2 ,  102  of the second guiding and supporting means  3 ,  103 ; 
     b—translating the ribbon-shaped element T, T 1  by an amount L 1 , corresponding to a bending position of the ribbon-shaped element T, T 1 ; 
     c—translating the tool  5 ,  105  through the first translating means  41 ,  1041 , in order to align the portion of bending profile  10 ,  110  of the tool  5 ,  105  with the portion of bending profile  8 ,  108  of the slit  2 ,  102 ; 
     d—translating the assembly of the second guiding and supporting means  3 ,  103  with the tool  5 ,  105  with respect to the first guiding and supporting means  1 ,  101 , by an amount H 1 , corresponding to a bending height of the ribbon-shaped element T, T 1 ; 
     e—rotating the rotation means  4 ,  104  by a suitable angle Alfa 1  to be able to bend the ribbon-shaped element T, T 1 ; 
     f—repeating step a; 
     g—translating the ribbon-shaped element T, T 1  by an amount L 2 , corresponding to a cutting position of the ribbon-shaped element T, T 1 ; 
     h—translating the tool  5 ,  105  through the first sliding means  41 ,  1041 , in order to align the portion of cutting profile  11 ,  111  of the tool  5 ,  105  with the portion of cutting profile  9 ,  109  of the slit  2 ,  102 ; 
     i—translating the assembly of the second guiding and supporting means  3 ,  103  with the tool  5 ,  105  with respect to the first guiding and supporting means  1 ,  101 , by an amount H 2 , corresponding to a cutting height of the ribbon-shaped element T, T 1 ; 
     l—rotating the rotation means  4 ,  104  by a suitable angle Alfa 2  to be able to cut the ribbon-shaped element T, T 1 . 
     With respect to handling of the two embodiments of the invention, there are elements related to position detection, such as proximities or encoders or limit switches (not shown). There are also suitable electric or electronic elements for driving the motors and interacting towards the users (not shown). It is provided to use suitable control algorithms.