Abstract:
An arrangement for transforming a planar support ( 2 ) includes first and second rotating cylindrical transformation tools ( 16, 17 ), cooperating to convert the support ( 2 ), first and second side bearings ( 26, 27 ), holding the first tool ( 16 ) for rotation (Rs), third and fourth side bearings ( 29, 31 ), holding the second tool ( 17 ) for rotation (Ri), spacers ( 43, 44, 46, 47 ) having an inclined face ( 48 ) and slidable (S) to adjust the respective distances (e, e 1 , e 2 ) between the first and third bearings ( 26, 29 ) and between the second and fourth bearings ( 27, 31 ), to set a radial gap ( 20 ) between the two tools ( 16, 17 ). In another solution, either as an alternative to or in cooperation with the first solution, the spacer ( 43 ) is moved (S) by a differential screw ( 57 ) having a first thread ( 58 ) that engages with a tapped hole ( 59 ) in an integral part ( 61 ) of one of the bearings ( 29 ) and a second thread ( 62 ) different than the first thread ( 58 ) and engaging with a tapped hole ( 63 ) in the spacer ( 43 ).

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application is a 35 U.S.C. §§371 national phase conversion of PCT/EP2014/000544, filed Mar. 4, 2014, which claims priority of European Application No. 13001150.5, filed Mar. 7, 2013, the contents of which are incorporated by reference herein. The PCT International Application was published in the French language. 
     
    
       [0002]    The present invention concerns an adjustable converting arrangement for a flat substrate, provided with two cylindrical converting tools, in a machine for producing packaging. The invention also relates to a converting cassette for a flat substrate, comprising an adjustable converting arrangement for the flat substrate. The invention concerns a converting unit for a flat substrate which is provided with a converting cassette for the flat substrate. The invention concerns a converting unit for a flat substrate, comprising at least one adjustable converting arrangement for the flat substrate. The invention also concerns a machine for producing packaging from a flat substrate, comprising a converting unit for the flat substrate. 
       TECHNICAL BACKGROUND 
       [0003]    A machine for producing packaging is intended for the manufacture of boxes which form the packaging, after folding and gluing. In the machine, an initial flat substrate, such as a continuous web of cardboard, is unwound and is printed by a print unit, made up by printing units. The web is then transferred into a converting unit, in order to make plate elements, in this case boxes. 
         [0004]    The converting unit comprises at least one converting arrangement provided with two cylindrical rotary tools, positioned parallel to one another and spaced apart with respect to the diameter of the tools, so as to cooperate. The web runs in a gap between the two tools in order to be converted there. Each of the two tools turns in a respective opposite direction. The first tool is rotatably mounted in a first and a second bearing and the second tool is rotatably mounted in a third and a fourth bearing. The first and third and also the second and fourth bearings are spaced apart with respect to the diameter of the tools. Tightening elements are provided in order to maintain the first and the third bearing as well as the second and the fourth bearing firmly together. Most of the time, the converting arrangement is provided so as to form a cassette. The cassette is inserted by sliding it into each of the lateral supporting frames of the unit. 
         [0005]    The cassette allows the tools to be changed quickly, in terms of the conversions of the substrate to be realized. The packaging manufacturer has at least two cassettes. A first cassette is in the machine currently operating and has been adapted in terms of the current converting job. During this time, a second cassette may be being assembled and adjusted so as to be adapted for the following converting job. When the job is to be changed, the operator takes out the old cassette and inserts the new cassette, reducing the time the machine is stopped to a minimum. 
         [0006]    As a first example, one of the arrangements or one of the cassettes is a rotary cutting arrangement or a rotary cutting cassette respectively. A first cylindrical cutting tool is provided with knives, and a second cylindrical tool is smooth and is called an anvil. At the moment of the cut, the edges of the knives of the cutting tool must pass as close as possible to the anvil cylinder so as to carry out a clean cut. The edges of the knives, however, must not touch the anvil cylinder as they would be irreparably destroyed during rotation. The constituent material of the support, i.e. the fibers in the case of cardboard, must not appear or be visible at the cut. Neither is it desirable to have dust originating from the cut in the constituent material of the support. 
         [0007]    This is why the optimum radial gap between the two cylindrical rotary tools is adjusted to a micron degree. So that said gap is obtained in such a precise manner, each end of the two cylindrical rotary tools comprises a bearing ring around a respective tool. The bearing ring at one end of one of the tools rolls on the bearing ring at the same end of the other of the tools (see document EP-0,764,505). 
         [0008]    As a second example, one of the arrangements or one of the cassettes is a rotary creasing arrangement or a rotary creasing cassette respectively. A first cylindrical creasing tool is provided with a male creasing form or matrix and a second cylindrical tool is provided with a complementary female creasing form or matrix. The creasing must be clean, with no fractures on the edges or the bottom of the creasing. In this case, the optimum radial gap between the two cylindrical rotary tools is adjusted to the hundredth of a millimeter. 
       PRIOR ART 
       [0009]    In order to obtain a first adjustment of the radial gap, the first and second bearings respectively are pressurized by means of jacks against the third and fourth bearings so as to apply the desired cutting pressure while obtaining the radial gap between the two tools. 
         [0010]    Documents FR-2,452,372 and EP-1,531,975 describe an arrangement in which the gap between the four bearings is adjusted with two wedges or spacers with an inclined face and sliding together. 
         [0011]    However, such an arrangement does not provide the possibility of adjusting the levels between the first and third bearings and between the second and fourth bearings. 
       SUMMARY OF THE INVENTION 
       [0012]    A main objective of the present invention consists in adjusting a converting arrangement for a flat substrate, intended for a converting unit in a machine producing packaging. A second objective is to realize a converting arrangement with rotary tools which allows a simpler, more sensitive and therefore extremely precise adjustment of the gap between the two tools to be obtained. A third objective is to provide an arrangement which allows the reproducibility of the adjustments between the rotary tools to be improved. A fourth objective is to resolve the technical problems mentioned for the arrangements of the prior art. A fifth objective is to simplify and to facilitate all tools changing in an arrangement, whilst simplifying and optimizing the later adjustments. A sixth objective consists in providing a cassette which comprises a converting arrangement for the converting unit. Yet another objective is that of succeeding in inserting a converting unit into a machine producing the packaging. 
         [0013]    A converting arrangement for a flat substrate comprises a first and a second cylindrical rotary converting tool. The first and the second cylindrical rotary converting tools are arranged to cooperate to provide a conversion of the flat substrate. The converting arrangement for the flat substrate comprises a first and a second lateral bearing. The first and the second lateral bearings hold the first cylindrical rotary tool for rotation. The converting arrangement for the flat substrate also comprises a third and a fourth lateral bearing. The third and the fourth lateral bearings hold the second cylindrical rotary tool for rotation. The converting arrangement for the flat substrate comprises adjustment means in the form of spacers, each of which has an inclined face and the spacers may slide together. The respective spacers adjust the gap between the first bearing and the third bearing. The respective spacers also adjust the gap between the second bearing and the fourth bearing. The spacers therefore allow a radial gap between the first cylindrical rotary converting tool and the second cylindrical rotary converting tool to be adjusted. 
         [0014]    In accordance with one aspect of the present invention, the converting arrangement for the flat substrate includes adjustment means that comprise two spacers which are inserted between the first lateral bearing and the third lateral bearing and two other spacers which are inserted between the second lateral bearing and the fourth lateral bearing. 
         [0015]    In other words, with two adjustable spacers for two bearings, the precision of the adjustment proves to be really superior. The adjustment allows the level of each of the two bearings to be well balanced and regulated on both sides of the arrangement. Such adjustments allow optimum conversion of the flat substrate to be retained all along the production. Four possibilities of adjustment are possible with four spacers. That multiplication of the adjustments also allows the manufacture of the bearings to be simplified. 
         [0016]    In accordance with another aspect of the present invention, in the converting arrangement for the flat substrate, the spacer is displaced by means of a differential screw, which has a first outer thread which cooperates with a first inner thread of a part which is joined with one of the lateral bearings, and has a second outer thread which is distinct from the first outer thread which cooperates with a second inside thread of the spacer. 
         [0017]    Expressed another way, with such a screw per spacer, the adjustment can be realized with much more precision, in terms of the dimensions of the chosen threads. Such an adjustment allows a high quality conversion of the flat substrate to be obtained and retained throughout the length of the production. 
         [0018]    Fine adjustment allows wear on one cylindrical rotary converting tool or on both cylindrical rotary converting tools, which takes place as they are used, to be compensated for in a progressive manner. The lifetime of the tool or tools is increased. Optimized adjustment also makes it possible to have bearings which are simpler to manufacture, requiring less machining precision. Fine, precise adjustment allows the time to adjust the radial gap between the two tools to be reduced. 
         [0019]    The flat substrate is defined, for example, as being of a material in a continuous web, such as paper, flat cardboard, corrugated cardboard, glued corrugated cardboard, flexible plastic, for example polyethylene (PE), polyethylene-terephthalate (PET), bioriented polypropylene (BOPP), or yet other materials. 
         [0020]    In another aspect of the invention, a converting cassette for a flat substrate comprises a converting arrangement for the flat substrate which has one or several of the technical characteristics described above. The converting cassette makes access, assembly and disassembly of the tools easier for the operator carrying out the adjustments and the maintenance of the unit and of the machine. 
         [0021]    According to another aspect of the invention, a converting unit for a flat substrate is provided with at least one converting cassette for the flat substrate, and the cassette is provided with a converting arrangement for the flat substrate, having one or several of the technical characteristics described above. 
         [0022]    According to another aspect of the invention, a converting unit for a flat substrate comprises at least one converting arrangement for the flat substrate, having one or several of the technical characteristics described above. 
         [0023]    According to yet another aspect of the invention, a machine for producing packaging from a flat substrate comprises at least one converting unit for the flat substrate, having one or several of the technical characteristics described above. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The invention will be well understood and its diverse advantages and different characteristics will be highlighted better from the following description and from the non-limiting exemplary embodiment, with reference to the accompanying schematic drawings, in which: 
           [0025]      FIG. 1  shows a schematic side view of a converting unit; 
           [0026]      FIG. 2  shows an isometric view of a cassette provided with a converting arrangement according to the invention; 
           [0027]      FIG. 3  shows a part side view of the cassette of  FIG. 2 ; 
           [0028]      FIG. 4  shows an isometric part view of the adjusting means; and 
           [0029]      FIGS. 5 and 6  show a part longitudinal sectional view of the adjustment means with a first and a second gap respectively. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    A machine for producing packaging (not shown) processes a material or a flat substrate which, in this case, is a substrate in the form of a continuous web, for example of flat cardboard. As shown in  FIG. 1 , the machine comprises a substrate converting unit  1  for converting the web  2 . The direction of feed or of unwinding (Arrow F in  FIG. 1 ) of the web  2  and of the converted web following the longitudinal direction indicates the upstream direction and the downstream direction of the unit  1 . The positions front and rear are defined with regard to the cross direction, as being the driver or operator side and the side opposite the driver or operator side respectively. 
         [0031]    The machine can have a web unwinder, units such as printer groups, means for controlling the quality and the register of the print, a web guiding means and other units which are positioned upstream of the unit  1 . 
         [0032]    The converting unit  1  is configured for separately embossing, creasing and cutting. The web  2  arrives in the unit  1  through the upstream transverse side thereof, at a constant speed. An introducing group comprising drive rollers and return rollers for the web  2  is provided at the input to the unit  1 . The unit  1  converts the web  2 , gradually by embossing it, creasing it and cutting it. 
         [0033]    The unit  1  delivers repeats or converted boxes  3 , which are embossed, creased and cut flat cardboard. The boxes  3  leave the unit  1  through the downstream transverse side thereof, at the same constant speed. The boxes  3 , prepared in the unit  1 , are then separated laterally and longitudinally from one another in a separating station and then are received in a receiving station (not shown). 
         [0034]    The unit  1  comprises a first arrangement configured for providing the embossing  4 , and arranged upstream, i.e. at the input, to said unit  1 . The embossing arrangement  4  is provided with a top rotary embossing tool  6 , positioned parallel to a bottom rotary embossing tool  7 . In this exemplary embodiment, an embossing cassette  8  comprises the embossing arrangement  4 . 
         [0035]    The unit  1  comprises a second arrangement configured for providing the creasing  9 , and disposed downstream of the embossing arrangement  4 . The creasing arrangement  9  is provided with a top rotary creasing tool  11 , positioned parallel to a bottom rotary creasing tool  12 . In this exemplary embodiment, a creasing cassette  13  comprises the creasing arrangement  9 . 
         [0036]    The unit  1  also comprises a third arrangement configured for providing the cutting  14 , and disposed downstream of the creasing arrangement  9 , i.e. at the output of the unit  1 . The cutting arrangement  14  is provided with a top rotary cutting tool  16 , positioned parallel to a bottom rotary cutting tool  17  wherein the tool  17  is e.g. in the form of a smooth unit for the cutting elements on the top cutting tool. In this exemplary embodiment, a cutting cassette  18  comprises the cutting arrangement  14 . 
         [0037]    The arrangements  4 ,  9  and  14 , and thus the cassettes  8 ,  13  and  18 , are placed following one another so that each one realizes its respective conversion, by embossing, creasing and cutting the web  2 . A waste ejecting tool in the form of a cylinder provided with ejecting spindles can also be provided in place of the bottom rotary cutting tool  17 . Other combinations are possible such as a top cylinder forming both a cutting tool and a creasing tool. 
         [0038]    The rotational axis of each of the tools for embossing  6  and  7 , creasing  11  and  12  and cutting  16  and  17  is oriented transversely with respect to the unwinding direction F of the web  2 . The rotational direction (Arrow Rs in  FIG. 2 ) of the top tools for embossing  6 , creasing  11  and cutting  16  is reversed with respect to the rotational direction (Arrow Ri in  FIG. 2 ) of the bottom tools for embossing  7 , creasing  12  and cutting  17 . 
         [0039]    The cassettes for embossing  8 , creasing  13  and cutting  18  are configured for being introduced into a supporting structure  19  of the unit  1 , for being attached to the supporting structure  19 , for producing, and then conversely, are configured for losing the positive connection with the supporting structure  19  and of being extracted from the supporting structure  19 . The unit  1  thus comprises three transverse housings provided in the supporting structure  19  for each of the three cassettes  8 ,  13  and  18 . The cassettes  8 ,  13  and  18  are introduced vertically, from above with respect to the supporting structure  19  and into the transverse housings. Conversely, the cassettes  8 ,  13  and  18  can be removed vertically with respect to the supporting structure  19 , out of their respective transversal housing. 
         [0040]    The cutting arrangement  14 , and therefore the cutting cassette  18 , comprises (see  FIG. 2 ) the top cylindrical rotary tool  16  which is provided with cutter threads (not shown) machined or built on its circumference in terms of the configuration of the boxes to be realized. The bottom cylindrical rotary tool or anvil  17  has a smooth circumference. The web  2  unwinds in direction F in the radial gap  20  between the top tool  16  and the anvil  17 . The top tool  16  is arranged so as to cooperate with the anvil  17  in order to convert, i.e. cut the web  2 . 
         [0041]    The top tool  16  is provided at each of its opposite ends with a bearing ring  21  or  22 , respectively. The anvil  17  is provided at each of its opposite ends with a bearing ring  23  or  24  respectively. The bearing rings  21  and  22  at the ends of the top tool  17  contact, bear on and roll on the respective opposite bearing rings  23  and  24  at the ends of the anvil  17 . 
         [0042]    The cutting arrangement  14 , and therefore the cutting cassette  18 , comprises a first top front bearing  26  and a second top rear bearing  27  at the ends of the top tool, which hold the first tool, here the top tool  16 , by its rotational axis  28  for rotation. The cutting arrangement  14 , and therefore the cutting cassette  18 , comprises a third bottom front bearing  29  and a fourth bottom rear bearing  31  at the ends of the second bottom tool which hold the second tool, here the anvil  17 , by its rotational axis  32  for rotation. The base of the two bottom bearings  29  and  31  rests on the supporting structure  19  when the cutting cassette  18  is inserted into the unit  1 . 
         [0043]    The cutting arrangement  14 , and therefore the cutting cassette  18 , comprises driving means which drive the two tools  16  and  17  in a rotating manner. The driving means are formed with a first top gear wheel  33  for the top tool  16  attached at the rear on its axis of rotation  28 . The first gear wheel  33  meshes with a second bottom gear wheel  34  for the anvil  17  which is attached at the rear on its axis of rotation  32 . When the cassette  18  is inserted into the supporting structure  19 , the teeth of the first gear wheel  33  mesh with the teeth of a gear wheel combined with an electric motor for rotational movement. 
         [0044]    The first top front bearing  26  of the top tool  16  is attached to the third bottom front bearing  29  of the anvil  17 , and the second top rear bearing  27  of the top tool  16  is attached to the fourth bottom rear bearing  31  of the anvil  17 , so as to constitute the cutting cassette  18 . To hold the cassette  18  in one single unit, elements, in the form of four ties  36 , front upstream, front downstream, rear upstream and rear downstream, extend in a vertical manner and are arrayed across the top front bearing  26  and the top rear bearing  27  respectively, and on both sides of the rotational axis  28  of the top tool  16 . The bottom end of each of the four ties, front and rear  36 , is threaded and that thread is screwed into a thread of the bottom front bearing  29  and of the bottom rear bearing  31  respectively. Four nuts  37 , front upstream, front downstream, rear upstream and rear downstream, are screwed onto the top end of the four ties  36  respectively. The nuts  37  block the ties  36  by bearing on a top face of the top front bearing  26  and of the top rear bearing  27  respectively and allowing the bearings and the ties to be prestressed. 
         [0045]    The cutting cassette  18 , as well as the cassettes for embossing  8  and creasing  13 , comprises two gripping lugs  41  each provided on the top face of the top front bearing  26  and of the top rear bearing  27 . The two lugs  41  are intended for cooperating with lifting means (not shown) to lift and transport the cassette  8 ,  13  and  18 . 
         [0046]    So as to provide a satisfactory functioning of the cutting cassette  18  or of the rotary cutting arrangement  14 , it is advisable to carry out a minute adjustment of the gap existing between the top tool  16  and the anvil  17 . To do this, adjustment means  42  are inserted between the first top front bearing  26  and the third bottom front bearing  29  and between the second top rear bearing  27  and the fourth bottom rear bearing  31 . 
         [0047]    The adjustment means  42  comprise spacers, in this case analogous to wedges, which are mobile by sliding. Four spacers  43 ,  44 ,  46  and  47  are provided according to the invention. A front upstream spacer  43 , a front downstream spacer  44 , a rear upstream spacer  46  (can be seen showing through in  FIG. 2 ) and a rear downstream spacer  47  allow for four different adjustments, front and rear, upstream and downstream. 
         [0048]    By displacing the spacers  43 ,  44 ,  46  and  47  laterally along their respective tools, a gap e (see  FIG. 4 ) varies, upstream and downstream, between the first bearing  26  and the third front bearing  29  and between the second bearing  27  and the fourth rear bearing  31 . The gap e is obtained as a result of a top inclined face  48  of the spacer  43 . Horizontalness adjustments in the longitudinal direction and in the cross direction are possible using the four spacers  43 ,  44 ,  46 , and  47 . 
         [0049]    As is shown in  FIGS. 3 and 4 , the spacer  43  is in the form of a metallic chock with two legs  49  and  51 , leaving a space in order to be enable pass through of the corresponding tie  36 . The two legs  49  and  51  of the spacer  43  are laid flat against the top face of the bottom front bearing  29 . The two legs  49  and  51  have a top inclined face  48 . 
         [0050]    An insert part  52 , also with two legs  53  and  54 , is favorably locked to the bottom face of the first top bearing  26  or to the second top bearing  27 . The two legs  53  and  54  of the insert part  52  comprise an opposite bottom inclined face  56 , corresponding to the top inclined face  48  of the spacer  43 . 
         [0051]    The sliding (Arrow S in  FIGS. 5 and 6 ) of the spacer  43  between the third bottom bearing  29  or the fourth bottom bearing  31  and the insert part  52  allows the gap e to be adjusted, the top inclined face  48  being laid flat against the opposite bottom inclined face  56  with different possible positions (see  FIGS. 5 and 6 ). The sliding S is along the longitudinal directions transverse to the length direction of the tools between the bearings at the ends of the tools. 
         [0052]    The action to adjust the gap e is defined as being the action to fill in the gap e between the bearings  26 ,  27 ,  29  and  31 , in the case of the cutting tools  16  and  17 . After adjustment by the spacers, the adjustment of the precise gap  20  is obtained by the bearing rings  21 ,  22 ,  23  and  24 . The action to adjust the gap e is defined as being the action to control the gap e of the precise gap  20  in the case of the tools for embossing  6  and  7  and for creasing  11  and  12 . 
         [0053]    In  FIG. 5 , the spacer  43  is at the bottom compared to the insert part  52 , and, as a result, the gap e 1  is the smallest. In  FIG. 6 , the spacer  43  is advanced compared to the insert part  52 , and, as a result, the gap e 2  is greater, in excess of the smallest gap e 1 . 
         [0054]    According to the invention, the spacer  43  is displaced by sliding S thanks to a screw  57 . The screw  57  is advantageously a differential screw which has a first outer thread  58  which cooperates with a first inner thread  59  of a part  61  which is joined with the bottom bearing  29 . The screw  57  connects the sliding spacer  43  mechanically to the immobile part  61 . The screw  57  has a second outer thread  62  which cooperates with a second inner thread  63  which is arranged in the mobile spacer  43 . The two threads  58  and  62 , and their corresponding thread  59  and  63 , allow the gap e to be finely adjusted, in terms of the difference in the chosen pitch. The difference in pitch corresponds to the sensitivity desired for the adjustment. The screw  57  has a different diameter at the two threads  58  and  62 . The second thread  62  has a larger diameter than the first thread  58 . When the screw  57  is turned (Arrow T in  FIG. 4 ) and progresses in a direction, the spacer  43  progresses S in the same direction. 
         [0055]    The spacers  43 ,  44 ,  46 , and  47  and the insert part  52  have an elongated form. The inclined face  48  of all the spacers  43 ,  44 ,  46  and  47 , and consequently the inclined face  56  of the insert part  52 , is preferably oriented along the longitudinal direction. In other words, the long length of the spacers  43 ,  44 ,  46  and  47  and of the insert part  52  is parallel to the longitudinal direction. Access to the screw  57  is upstream and downstream of the arrangement  14  and/or of the cassette  18 , which proves more ergonomic for the operator. 
         [0056]    In an advantageous manner, the cutting arrangement  14  further comprises a plane chock with a predefined thickness  64 , inserted between the first top bearing  26  or the second top bearing  27  and the insert part  52  with the inclined face  56 . The plane chock  64  allows for adaptation when using cylinders  16  and  17  with different diameters. 
         [0057]    With a more ergonomical converting unit  1 , the risk of errors is strongly reduced, which, as a consequence, brings about a reduction in non-standard boxes or in boxes not having an optimum quality. 
         [0058]    The present invention is not limited to the embodiments described and illustrated. Numerous modifications can be realized without in any way departing from the framework defined by the scope of the set of claims.