Patent Publication Number: US-2017355533-A1

Title: Grasping member and assembly for transferring hollow glass item

Description:
PRIORITY CLAIM 
     This application claims priority from Italian Patent Application No. 102016000061202 filed on Jun. 14, 2016, the disclosure of which is incorporated by reference. 
     TECHNICAL FIELD 
     The present invention relates to a grasping member for transferring hollow glass items. 
     BACKGROUND OF THE INVENTION 
     The present invention applies specifically to machines for moulding hollow glass items, commonly known as I.S. machines. Said machines generally comprise a plurality of moulding sections operating parallel to each other and each comprising their own moulding dies with one or more moulding cavities designed to realise respective hollow glass items, in sequence, according to a predefined moulding plan. 
     The items coming out of the dies of each moulding section are first transferred onto a relative supporting plate commonly known as a “dead plate” and from here, they are subsequently moved to a discharge conveyor common to all sections. 
     The items are moved by each supporting plate to the conveyor along a curved path using a thrust device having one or more motorised articulated arms and a grasping member, commonly known as a “shovel”. 
     The grasping member is coupled to the free end of the articulated arm and presents one or normally, more aligned spaces, each housing one of the items to be transferred, when in use. The spaces are generally defined by a pair of vertical flat plates that are mutually orthogonal and against which the relative item is arranged. 
     In some cases, the items are held in contact with the plates using a pneumatic suction device designed to create a depression area between the plates and the item to be transferred. 
     Although used, the known grasping members of the type described above are inadequate for the following reasons. 
     First and foremost, the pneumatic devices are inefficient in the case of items that are multi-faceted or delimited by tapered, convex or flat outer surfaces as it is difficult to obtain and maintain a sufficient depression in the stated area and consequently realise an efficient and invariant locking action. 
     Besides this, the pneumatic devices cool the items locally creating unwanted differences in temperature and, consequently, inconsistent cooling of the items. 
     Not only, but the forces generated by the pneumatic devices deform the items being produced unpredictably, to such an extent that the items do not pass the geometric and dimensional quality checks and consequently have to be discarded at the end of the production cycle. 
     Finally, the pneumatic devices are not able to guarantee constant angular positioning of the item inside the relative space during the whole transfer phase. In fact, the combination of the centrifugal and inertia action and the friction components along the transfer path, on the supporting plate, generate a torque on the items that makes the items rotate on themselves around vertical axes. Although said rotation causes only minimal problems during the transfer of cylindrical items, such as common cylindrical bottles, it is, however, problematic in the case of multi-faceted items or items with polygonal sections in plan view. After rotating on themselves, said items are released onto the conveyor in positions that are angular and non-predefinable, but above all, different to each other. Arbitrary angular positions create grasping problems in the subsequent automatic handling of the items. 
     SUMMARY OF THE INVENTION 
     The aim of the present invention is to realise a grasping member, which provides a simple and cheap solution to the previously stated problems and, in particular, a grasping member that makes it possible to arrange the items in an equioriented position on the discharge conveyor. 
     A further aim of the present invention is to realise a grasping member that is simple and cheap to make, with a contained weight that is easy to replace and adapt quickly to different productions. 
     According to the present invention, a movable grasping member is provided, as claimed in claim  1 . 
     Moreover, the present invention relates to a method for transferring hollow glass items. 
     According to the present invention, a method is provided for transferring hollow glass items, as claimed in claim  16 . 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will now be described with reference to the accompanying drawings, which illustrate a non-limiting embodiment, wherein: 
         FIGS. 1 and 2  schematically illustrate a preferred embodiment, substantially in blocks, of an assembly for transferring hollow glass items according to the dictates of the present invention, arranged in two different functional positions; 
         FIGS. 3 and 4  illustrate a detail in  FIGS. 1 and 2  in side elevation and plan view respectively; 
         FIGS. 5 and 6  illustrate two different variations of the detail in  FIG. 3 ; and 
         FIG. 7  illustrates several variations of the detail in  FIG. 5 , on an enlarged scale. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In  FIG. 1, 1  globally indicates an assembly for transferring glass items  2  onto an I.S. machine  3  for moulding the glass items  2 . The machine  3  itself is known and partially visible in  FIGS. 1 and 2  and comprises a plurality of moulding sections  4 , only one of which is partially visible in  FIGS. 1 and 2 . 
     In turn, each section  4  comprises a relative die assembly  5  for moulding the items  2  and a device  7  for moving the items  2  from the die assembly  5  to a relative horizontal supporting plate  10  commonly known as a “dead plate”. 
     The plate  10  constitutes part of an assembly  12  for transferring the items  2  resting on the plate  10 . Besides the plate  10 , the assembly  12  comprises a conveyor  13  for discharging items, in turn, comprising a horizontal delivery branch  14  alongside the plate  10  and coplanar with the plate  10  designed to move the items  2  in one direction  15 . 
     Again with reference to  FIGS. 1 and 2 , the assembly  12  also comprises a transfer device  16  for collecting the items  2 , in this particular case three, from the plate  10  and arranging them in an equioriented position on the delivery branch  14  ( FIG. 2 ). 
     The transfer device  16  comprises a motorised articulated arm, known and indicated by  19 , and an item grasping assembly  20  carried by the arm  19  itself. 
     In the particular illustrated example, the arm  19  comprises a crank  21  having a terminal portion mounted onto a motorised rotating shaft  22  with a revolving action around a fixed axis  23  orthogonal to the plate  10  and the branch  14 . The arm  19  also comprises a connecting rod  24  hinged to the crank  21  to rotate around a movable hinge axis  25  and holding, coupled to one of its free ends, the assembly  20 . 
     Again in the illustrated example, the grasping assembly  20  comprises an attachment bar  26  jointly connected to the connecting rod  24  and three grasping members  27 , one for each item  2 , coupled in spaced out positions, which can be adjusted along the bar  26 . 
     According to a non-illustrated variation, the assembly  20  comprises a motorised, or not, angular adjustment device inserted between the connecting rod  24  and the bar  26  to vary the position of the bar  26  in relation to the connecting rod  24  around a vertical axis. 
     Whereas, according to a further non-illustrated variation, the connecting rod  24  carries a single grasping member  27 . 
     Independently of the number, each grasping member  27  is a member realised in one single piece. Advantageously, each member  27  is realised from a flat metallic plate cut with a laser and bent in a U-shape ( FIG. 3 ). 
     Each member  27  delimits, in any case, a seat  28  that rounds up an end perimeter portion  2 A of the item  2  to allow the item  2  to go in and come out during the steps of collection from the supporting plate  10  and during the release onto the conveyor  13  respectively and, at the same time, to prevent the rotation of the relative item  2  inside the seat  28 , that is in relation to the member  27 , around vertical axes and parallel to the axes  23  and  25 , as we can see in  FIGS. 3 and 4 . 
     In particular, each member  27  comprises a vertical portion  30  with a plate fixed, for example with screws, to a K member for attaching to the bar  26  ( FIGS. 1 and 2 ), which can be positioned along the bar  26  or to the angular adjustment device, when present. 
     Moreover, each member  27  comprises two horizontal portions shaped in a C or a U, indicated in  FIG. 3  by  31  and  32 . The portions  31  and  32  are plate-shaped portions, or better cut plates, parallel to the supporting plate  10 , they each have a recess that defines the seat  28 , at least partially, and they extend in an overhanging manner from a lower terminal section and from an upper terminal section of the portion  30  and from opposite parts of the portion  30  in relation to the bar  26  respectively. 
     The portions  31  and  32 , in this particular case, having identical geometries and dimensions, each envelop or surround a relative part  31 A,  32 A of the portion  2 A. 
     The portions  31  and  32  comprise respective arms  33  and  34  which face each other and are coplanar with and parallel to the plate  10  and a relative crosspiece  35  for connecting the arms  33  and  34 . The arms  33  are stably connected to the portion  30  and have a length measured parallel to the bar  26  or to the greater direction  15  of that of the arms  34 . The arms  34  end with a section that is tapered towards the free end to facilitate the item  2  going in and coming out. 
     The recesses of the portions  31  and  32  are delimited by respective surfaces  37  and  38 , which follow the outer lateral surfaces of the respective parts  31 A and  32 A. In this case and with reference to  FIG. 4 , the inner surfaces  37  and  38  have a profile, in plan view, which is practically complementary to the profile of the projections in plan view of parts  31 A and  32 A. A minimum play is present between the two profiles to allow the insertion into, and the extraction of the item  2  from, the seat  28 . 
     Again with reference to  FIG. 3 , each of the inner surfaces  37  and  38  comprises two respective curved areas with identical or different concavities facing each other. The curved areas delimit the arms  33  and the arms  34  and converge towards each other and towards the relative crosspiece  35 . Again, in this case, each crosspiece  35  is delimited by a flat area of the relative surface  37 ,  38 . According to a non-illustrated variation, the crosspieces  35  are also delimited by curved surfaces. 
     In the variation illustrated in  FIG. 6 , the portions  31  and  32  envelop parts  31 A and  32 A, which are opposite terminal parts of the item  2 , in this particular case a bottom portion and a neck portion. In this case, the surfaces  37  and  38  have different geometries and dimensions and consequently corresponding areas with a different curvature and this in itself is enough to create an anti-rotating action of the item  2  in the seat  28 . 
     The variation illustrated in  FIG. 5 , relates to a member  40 , which differs from the member  27  in that it only comprises portion  32 . In this case, the portion  32  is set at a height from the supporting plate  10  that is chosen according to the varying dimensional and geometric characteristics and the mass of the item  2  to be transferred and, in particular, to avoid the formation of torques tending to overturn the item during transfer. Advantageously, but not necessarily, the portion  32  acts on the centre of gravity of the item or around the centre of gravity. 
     In the variation illustrated in  FIG. 7 , the portion  30  is coupled to the attachment member K by means of a quick coupling device  42 . The device  42  is designed to allow the member  40  to be replaced rapidly, without requiring any special equipment or simple keys, but above all to allow the member  40  to be extracted from above. 
     In this particular case, the device  42  comprises a vertical guide defined, in this case, by a vertical opening  43  made on the K body, and an attachment portion defined, again in this case, by a vertical plate  44  made up of a terminal section of the portion  30  and engaging the opening  43  in a sliding manner. A projection  45  of the portion  30  rests on the K member to stop the member  40  vertically and allow the free vertical extraction of the member  40  itself. 
     Of course, a similar quick change device of the type previously described can be used for coupling the members  27 . Advantageously, in this case, the plate  44  is defined by an intermediate portion of the portion  30  and it is obtained, advantageously, by cutting and plastic deformation of the portion  30 . In this way, the portion  30  and the plate  44  constitute part of a body made in one single piece. 
     Independently of how the attachment plate  42  is made, the possibility of extracting the grasping members from above significantly reduces the intervention time and has proven to be extremely advantageous as the free spaces in the area where the transfer assembly  12  of the items works  2  are reduced. 
     Again with reference to  FIG. 7 , the arms  33  and  34  and the crosspiece  35  are no longer delimited by practically smooth surfaces but by respective rough surfaces. The arms  33  and  34  and the crosspiece  35  preferably end with respective serrations having rounded teeth  46  or flat ends to avoid damaging the item  2  being transferred and create an effective anti-rotation action of the item  2  at the same time and a minimum heat exchange, resulting from a minimum contact surface. According to non-illustrated variations, serration is only foreseen on the arms  33  and  34 , or on only one of the arms  33 ,  34 . 
     In use, considering only one item  2  to be transferred for simplicity, arranged on the plate  10 , the grasping member  27 , 40  is moved by the arm  19  and the item  2  gradually inserted into the seat  28 . During insertion, the item  2  is gradually taken by portions  31 , 32  and arranged in a reference position imposed by the gradual support against the inner surfaces  37 , 38 , consequently, when insertion is complete, the item  2  is arranged in a predefined and desired reference position in relation to the grasping member. At this point, the member  27 ,  40  gradually moves the item  2  towards the conveyor  13  along a predefined curved path. During said movement, the item  2  is always enveloped and held by the portions  31 , 32 , which prevent it not only from leaving the seat  28  as a result of a centrifugal effect, but also from rotating on itself inside the seat  28 , thus maintaining its initial reference position. 
     From the above, it is clear how, on the one hand, the presence and conformation of the portions  31 , 32  or of just portion  32  without portion  31 , makes it possible to position the items  2  on the conveyor  13  in predefined and equioriented positions, eliminating all problems at the root related to the subsequent robotic handling of the items  2 . 
     Compared to the known retaining methods, the fact of retaining each item  2 , distributing the retaining action on one or more extended outer surfaces for supporting the item  2  on portions  31 , 32  allows us to obtain items without dents, scratches and localised deformations in general, caused during the known solutions, also in part by rotation inside the seat, preserving both the aesthetic quality of the item produced and the structural consistency of the item itself. 
     Lastly, the advantages, which can be gained in terms of quality and positioning constancy of the previously described transferred product by using a grasping member that is extremely simple to make, cheap and with a low weight, are evident. The described member  27  can, in fact, be obtained extremely quickly, starting from a simple plate with a thickness of between 1 and 5 millimetres or a flat sheet, that is a common surface with a thickness of 2 or 3 millimetres, which is cut using a common laser beam to make the surfaces  37  and  38 , simply bent in the shape of a U and deformed plastically to make the quick change device  42  when foreseen. Besides being simple, cheap and geometrically stable, such a procedure means that the seat  28  can be conformed according to the aesthetic and/or geometric characteristics of the product to be transferred and that the configuration of the transfer assembly can be modified quickly with every production change. In other words, the described procedure makes it possible to obtain cheap transfer members for transferring a specific item regardless of the geometric characteristics of the item in question. 
     From the above, it is clear that modifications and changes can be made to the described transfer member  27 , 40  without going beyond the protective scope defined by the independent claims. 
     In particular, portions  31  and  32  may present a different structure or different dimensions and geometries from those specified by way of example to adapt to the dimensions/geometries, shape and weight of the items to be transferred. 
     Similarly, the attachment portion  30  may present a different shape and/or geometries to those specified for the use of quick change or attachment devices different to those described above.