Abstract:
A conveyor for conveying good. According to one embodiment the conveyor includes a holding unit for holding or releasing the goods with respect to a conveyor belt. The holding unit includes vacuum holding means and magnetic holding means. The magnetic holding means includes at least one movable element that comprises at least one magnet or has a magnet attached thereto. The movable element is able to deactivate the magnetic holding means by distancing the magnet from the conveyor belt, and is also able to be arrange in a closed position in which the movable element blocks a vacuum conduit extending through the conveyor belt.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application relates to and claims the benefit and priority to European Application No. EP16382004, filed Jan. 7, 2016, which is incorporated by reference herein in its entirety. 
       FIELD 
       [0002]    The present invention relates to conveying devices and methods for conveying goods, particularly goods in the form of a sheet. 
       BACKGROUND 
       [0003]    Conveying devices and methods for conveying goods, particularly goods in the form of a sheet, are known. Devices comprising conveyor means in the form of one or more rotating conveyor belts rotating around driven wheels, the goods in the form of a sheet being conveyed hanging from the lower side of the belts, are known. The goods are held or released with respect to the conveyor belt by means of magnetic holding means for conveying ferromagnetic goods, or by vacuum holding means for conveying ferromagnetic and/or non-ferromagnetic goods. 
         [0004]    WO2010124767A1 discloses a conveying device for conveying goods, particularly goods in the form of a sheet, comprising conveyor means for conveying the goods and a holding unit for holding or releasing the goods with respect to the conveyor means, the holding unit comprising both vacuum holding means and magnetic holding means, the holding unit comprising a plurality of vacuum conduits that allows communicating the vacuum holding means with the conveyor means. 
       SUMMARY OF THE DISCLOSURE 
       [0005]    According to one embodiment a conveying device for conveying goods, particularly goods in the form of a sheet, is provided comprising conveyor means for conveying the goods and a holding unit for holding or releasing the goods with respect to the conveyor means, the holding unit comprising vacuum holding means and magnetic holding means, the holding unit comprising at least one vacuum conduit that allows communicating the vacuum holding means with the conveyor means. 
         [0006]    The magnetic holding means comprise at least one movable element comprising at least one magnet, being able to deactivate the magnetic holding means by distancing the movable element from the conveyor means, and being able to arrange the movable element in a closed position in which the movable element blocks the vacuum conduit. 
         [0007]    Another aspect relates to methods for conveying goods, particularly goods in the form of a sheet, implemented with a conveying device for conveying goods such as that defined above. 
         [0008]    The device allows, with a simple movement of a movable element, which in turn comprises a magnet, deactivating the magnetic holding means by distancing the movable element from the conveyor means, and therefore allows releasing the conveyed goods when the device works with the magnetic holding means, and furthermore allows arranging the movable element in a closed position in which the vacuum conduit is blocked, and thereby prevents holding of the goods by means of the vacuum holding means. 
         [0009]    Therefore, a simple conveying device is obtained which allows, with few elements and a displacement of a movable element, operation of the device with magnetic holding means and vacuum holding means, the movable element performing a dual function: a first function associated with the activation/deactivation of the magnetic holding means, and a second function associated with the activation/deactivation of the vacuum holding means. 
         [0010]    These and other advantages and features will become evident in view of the drawings and of the detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIG. 1  shows a schematic view of a conveying device for conveying goods according to one embodiment. 
           [0012]      FIG. 2  shows a cross-section view of the embodiment of  FIG. 1 , the movable element of the magnetic holding means being in a closed position, and a ferromagnetic part being held with respect to the conveyor means by means of the magnetic holding means. 
           [0013]      FIG. 3  shows a cross-section view of the embodiment of  FIG. 1 , the movable element of the magnetic holding means being distanced from the conveyor means, and a part being held with respect to the conveyor means by means of the activated vacuum holding means. 
           [0014]      FIG. 4  shows a cross-section view of the embodiment of  FIG. 1 , the movable element of the magnetic holding means being in a closed position, and the part being released from the conveyor means, the magnetic field of the magnet of the movable element not being depicted. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]      FIG. 1  shows a schematic view of a conveying device  100  for conveying goods according to one embodiment. The conveying device  100  for conveying goods, particularly goods  50  in the form of a sheet, conveys ferromagnetic or non-ferromagnetic goods  50 , such as for example sheets of aluminum or plastic, from a preceding manufacturing process or from a stacking area depicted by means of a discharge conveyor  70 , to a stacking area  90  for stacking the goods  50 , the conveying direction being depicted by means of the arrow  80 . 
         [0016]    The device  100  comprises conveyor means  20  for conveying the goods  50 , the conveyor means  20  in this embodiment comprising an upper side  22  and a lower side  21  rotating around two mechanically- and/or electrically-driven wheels  25 ,  26 . The lower side  21  of the conveyor means  20  is oriented at one end towards the discharge conveyor  70 , and at the other end towards the stacking area  90  for stacking the goods  50 . The goods  50  are held by and hang from the lower side  21 , being released when the goods  50  reach the stacking area  90 . 
         [0017]    The device  100  also comprises a holding unit  10  for holding or releasing the goods  50  with respect to the conveyor means  20 , specifically with respect to the lower side  21 . The holding unit  10  comprises vacuum holding means  30  and magnetic holding means  40  configuring what is referred to as a hybrid conveying device for conveying goods. In this embodiment, the holding unit  10  comprises a plurality of vacuum conduits  33  that allows communicating the vacuum holding means  30  with the lower side  21  of the conveyor means  20 , the vacuum conduits  33  being close to the conveyor means  20 . 
         [0018]    In this embodiment of the device  100 , the magnetic holding means  40  comprise a plurality of movable elements  41 , each of them comprising a magnet  42 . Specifically, in this embodiment of the device  100 , the movable element  41  is the magnet  42  itself, the magnet  42  therefore being the displaced element. In other embodiments of the device  100 , not shown in the drawings, the magnet forms part of the movable element. According to one embodiment the device  100  comprises as many movable elements  41  as there are vacuum conduits  33 , each movable element  41  being associated with a vacuum conduit  33 . These movable elements  41  are operated by means of actuators  60 , these actuators preferably being pneumatic or hydraulic piston and cylinder units, but they could also be rack and pinion units, cams or actuators of another type. 
         [0019]    In this embodiment, the magnet  42  is a permanent magnet that does not require maintenance and does not require energy for activation or deactivation. This permanent magnet can be a basic magnet formed by ferrites, or it can be a neodymium magnet conferring greater attractive force with a lower weight. 
         [0020]    The magnet  42  also can be an electromagnet (not depicted in the drawings). However, magnets of this type are more expensive due to both their structure and their maintenance, requiring external energy for activation and deactivation thereof, and thereby being able to hold or release the conveyed goods. 
         [0021]      FIGS. 2, 3 and 4  show cross-section views of the embodiment of the device  100  of  FIG. 1 . 
         [0022]    The plurality of movable elements  41  are housed inside a vacuum chamber  32  comprising the vacuum holding means  30 . The actuator elements  60  move the movable elements  41  inside the vacuum chamber  32  in a linear path that is perpendicular to the conveyor means  20 . Other paths are also possible, displacing the movable element  41  in a circular path, or in a linear path but one that is not perpendicular to the conveyor means  20 . 
         [0023]    The vacuum chamber  32  may be an elongated chamber that is projected in the longitudinal direction of the device  100 , the device  100  being able to comprise more than one vacuum chamber  32 . In addition, in this embodiment the vacuum holding means  30  comprise a vacuum source  31 , for example a suction or vacuum pump, which generates a vacuum in the vacuum chamber  32  through a vacuum duct  34 . The vacuum conduits  33  are arranged in the vacuum chamber  32 , in the lower part thereof, the side  21  of the conveyor means  20  being arranged adjacent to the lower part of the vacuum chamber  32  on the outer part thereof. Therefore, each vacuum conduit  32  allows the fluidic connection between the inside of the vacuum chamber  32  and the lower side  21  of the conveyor means  20 . 
         [0024]    In this embodiment of the device  100 , the conveyor means  20  comprise two conveyor belts  23 ,  24  arranged parallel and adjacent to the lower part of the vacuum chamber  32 . These conveyor belts  23 ,  24  provide an opening therebetween, in which the vacuum conduits  33  are arranged, such that the vacuum conduits  33  are arranged laterally adjacent to the conveyor belts  23 ,  24 . Therefore, the conveyor belts  23 ,  24  allow the passage of air between the vacuum chamber  32  and the goods  50  arranged adjacent to the conveyor belts  23 ,  24  on the outer part thereof, through the vacuum conduits  33 . In other embodiments of the device  100 , not shown in the drawings, the conveyor means  20  comprise a single conveyor belt adjacent to the lower part of the vacuum chamber  32  and allow the passage of the air therethrough, for example due to their own structure, or due to the conveyor belt comprising a plurality of openings going through it and coinciding with the vacuum conduits  33 . 
         [0025]    The magnetic holding means  40  are activated and deactivated by means of the displacement of the movable elements  41 . The magnetic holding means  40  are activated, as shown in  FIG. 2 , by the movable elements  41  moving and getting closer inside the vacuum chamber  32  to the conveyor belts  23 ,  24  of the conveyor means  20 , the goods  50 , which in this case are ferromagnetic goods, hanging and being held in the outer part of the conveyor belts  23 ,  24 . The magnets  42  of the movable elements  41  each form a magnetic field  43  comprising field lines  44 . As the movable element  41  gets closer to the goods  50 , the field lines  44  in the goods  50  close, the goods  50  being held with respect to the conveyor belts  23 ,  24 . In this activation position of the magnetic holding means  40 , the movable elements  41  are arranged in a closed position, the movable elements  41  blocking each of the corresponding vacuum conduits  33 . Therefore, in this embodiment of the device  100  it is the magnet  42  itself that blocks each of the vacuum conduits  33  in the closed position of the movable elements  41 . To block the vacuum conduits  33 , the movable elements  41 , which in this embodiment of the device  100  coincide with the magnets  42 , comprise a respective gasket  45 , such that in the closed position of the movable elements  41  the magnets  42  are fitted to the vacuum conduits  33  in the inner part of the vacuum chamber  32 , and with the help of the gaskets  45  they make the closure leak-tight. 
         [0026]    To deactivate the magnetic holding means  40 , the movable elements  41  move and, inside the vacuum chamber  32 , are distanced from the conveyor belts  23 ,  24  of the conveyor means  20 . Therefore, the field lines  44  do not close in the goods  50 , such that the goods  50  are released from the conveyor belts  23 ,  24 . The movable elements  41  must be sufficiently distanced from the goods  50  so that the field lines  44  of the magnetic fields  43  of each of the magnets  42  do not close in the goods  50 . In this distancing position of the movable elements  41  with respect to the vacuum conduits  33 , the movable elements  41  do not block the vacuum conduits  33 , and therefore there is fluidic communication between the vacuum chamber  32  and the goods  50 . 
         [0027]    In one embodiment of the device  100 , the device  100  comprises a vacuum source  31 , which is a suction or vacuum pump, and also a fan. When the magnetic holding means  40  are deactivated by means of the displacement and distancing of the movable elements  41  with respect to the conveyor belts  23 ,  24 , the vacuum source  31  optionally works as a fan and air is expelled through the vacuum conduits  33 , which are now open, thereby helping to release the ferromagnetic goods  50  from the conveyor belts  23 ,  24 . 
         [0028]    The vacuum holding means  30  is activated, as shown in  FIG. 3 , by activating the vacuum source  31 , such that a vacuum is generated in the vacuum chamber  32  through the vacuum duct  34 . By displacing and distancing the movable elements  41 , inside the vacuum chamber  32 , from the conveyor belts  23 ,  24  of the conveyor means  20 , the field lines  44  of the magnetic field  43  of each of the magnets  42  are not closed in the goods  50 , which can be ferromagnetic or non-ferromagnetic. The movable elements  41  do not block the vacuum conduits  33 , and therefore there is fluidic communication between the vacuum chamber  32  and the goods  50 . The goods  50  are therefore held against the conveyor belts  23 ,  24  on the outer part thereof. 
         [0029]    The vacuum holding means  30  is deactivated, as shown in  FIG. 4 , by the movable elements  41  displacing and getting closer to the conveyor belts  23 ,  24  of the conveyor means  20 , taking the movable elements  41  to their closed position. The movable elements  41  thereby block the vacuum conduits  33 , and therefore there is no fluidic communication between the vacuum chamber  32  and the goods  50 , even though the vacuum source  31  is activated. Therefore, the goods  50  are released from the conveyor belts  23 ,  24 . 
         [0030]    The invention also relates to methods implemented by means of the device  100  of the invention. A first method comprises:
       a step of supplying the device  100  with ferromagnetic or non-ferromagnetic goods  50  from a previous stacking area or process,   a step of holding by means of the vacuum holding means  30 , wherein the movable elements  41  are not in the closed position, and therefore the vacuum holding means  30  hold the goods  50 , and   a step of releasing the goods  50 , preferably into a stacking area  90 , wherein the movable elements  41  are arranged in the closed position, and therefore the vacuum holding means  30  release the goods  50 .       
 
         [0034]    A second method that may be used when the conveying process is for conveying goods made of ferromagnetic material, comprises:
       a step of supplying the device  100  with ferromagnetic goods  50 ,   a step of holding by means of the magnetic holding means  40 , wherein the movable elements  41  are in the closed position, and the magnetic holding means  40  therefore hold the goods  50 , and   a step of releasing the ferromagnetic goods  50 , preferably into a stacking area  90 , wherein the movable elements  41  are distanced from the conveyor means  20 , and the magnetic holding means  40  therefore release the goods  50 .       
 
         [0038]    In an embodiment of this second method, in this step of releasing the ferromagnetic goods  50 , the vacuum holding means  30  expel air through the vacuum conduits  33 , contributing to the release of the goods  50 .