Abstract:
A system ( 1 ) and a method for assembling laminated structures utilising a robot ( 10 ) for collecting and placing sheet-shaped material, further utilising an adhesive applicator ( 13 ) which is collected from an adhesive applicator rest station ( 14 ) by the robot ( 10 ), is used to apply adhesive to the sheet-shaped material, and is then returned to the adhesive applicator rest station ( 14 ).

Description:
RELATED APPLICATIONS 
       [0001]    This application is a U.S. national phase application of International Application number PCT/EP2014/053597 filed Feb. 25, 2014 claiming priority of Switzerland application 00521/13 filed Feb. 28, 2013. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to a method and system for assembling laminated structures from sheet-shaped material. 
       BACKGROUND AND SUMMARY 
       [0003]    Sheet-shaped or plate-shaped materials in general are materials which have a thickness significantly less than their length and breadth, and may be of constant thickness, or have varying thickness such as a wedge-shape. Such materials may be of rectilinear or curved form, or a combination of both. 
         [0004]    In many automated industrial assembly situations for assembling laminated structures, it can be uneconomic to have a high degree of assembly robot specialisation due to the capital costs that procuring such highly specialised equipment entails. As such, it is often preferable to be able to utilise the same robot for multiple assembly steps,  either in a serial production line or in piece-by-piece assembly. 
         [0005]    In the present case of assembling laminated structures from sheet-shaped material, the same robot may be required to both position material, and to apply adhesive to the surface of the material, and then to position the next piece of material upon the first so as to form a laminated structure. However, merely integrating an adhesive applicator into the robot entails significant challenges. In the case of modern, highly adaptable assembly robots with multiple degrees of freedom, a significant length of adhesive conduit is required for non-self-contained adhesive applicators, which may impinge upon the movement of the robot, or may become entangled therein, becoming damaged. Furthermore, such a length of conduit contains a significant amount of adhesive, which leads to wastage. And finally, adhesive may drip from the adhesive applicator during movement of the robot, which may reduce the quality of the final product, or pollute the workplace. This latter can even be a problem with more simple robots with few degrees of freedom. 
         [0006]    An object of the present invention is thus to overcome at least one of the above-mentioned disadvantages. 
         [0007]    This object is achieved by a system for assembling laminated structures from sheet-shaped material according  to the invention. The system comprises at least one material input station for providing sheet-shaped material. Such a material input station may be simply a table or support upon which sheet-shaped material is placed either manually or automatically, may be a rack arrangement in which multiple pieces of sheet-shaped material are mounted, or may simply be a stack of sheet-shaped material. Alternatively, the material input station may be a previous station, such as a work station, in a production assembly line. A work station for processing said sheet-shaped material is provided, which may be merely a table or support, or a more complicated arrangement e.g. involving a conveyor. An adhesive applicator arrangement comprising at least one adhesive applicator which may be stand-alone or connected to an adhesive reservoir e.g. by a hose, is provided, for applying adhesive to the sheet-shaped material, and an adhesive applicator rest station is provided for receiving the adhesive applicator. A robot which is movable on or about at least one axis, i.e. is a Cartesian, polar, or combined Cartesian and polar robot, is provided. This robot is adapted to be able to collect sheet-shaped material from the material input station and to deposit the sheet-shaped material at the work station. The robot is furthermore adapted to collect the adhesive applicator from the adhesive applicator rest station, to apply adhesive from said adhesive applicator to the sheet-shaped material deposited at said work station, particularly to the upper surface of the sheet-shaped material, and to return the adhesive applicator to the adhesive applicator rest station. In consequence, the same  robot can be utilised for both collecting and positioning sheet-shape material, and for applying adhesive thereto, without requiring that an adhesive applicator be integrated into the robot, or to be permanently attached thereto. Thus, extensive and complicated hoses etc which may become tangled in the robot are no longer needed, and the risk of adhesive dripping from the adhesive applicator is limited to the area between the adhesive applicator rest station and the work station rather than to the entire area of movement of the robot. 
         [0008]    In an embodiment of the system, the robot comprises a manipulation head which comprises a first manipulator for releasably holding the sheet-shaped material and a second manipulator for releasably holding the adhesive applicator. Thus a single manipulation head on the robot can handle both the sheet-shaped material and the adhesive applicator. The first manipulator and the second manipulator may each comprise at least one of: at least one gripper (i.e. with at least two opposed fingers or similar), at least one pneumatic suction cup, at least one electromagnet. 
         [0009]    In an embodiment of the system, the adhesive applicator arrangement comprises an adhesive reservoir in operative connection with the adhesive applicator and comprises means for forcing adhesive towards the adhesive applicator. Thus continuous operation of the adhesive applicator can be assured. The aforementioned means for forcing adhesive towards the adhesive applicator may comprise at least one of: a pump, a piston arrangement, a pressurized gas arrangement, a gravity-feed arrangement.  
         [0010]    In an embodiment of the system, the adhesive applicator rest station comprises a liquid reservoir for holding a quantity of a liquid agent, such as an anti-curing, anti-oxidation, or anti-drying agent, in contact with at least part of the adhesive applicator (i.e. at least the adhesive outlet) when the adhesive applicator is positioned in the adhesive applicator rest station. In consequence, undesired hardening or thickening of the adhesive in the adhesive applicator exposed to the air is avoided when the adhesive applicator is positioned in the adhesive applicator rest station. 
         [0011]    In an embodiment of the system, the laminated structures referred to are building integrated photovoltaics, also known as Structurally Integrated Solar Building Elements, which comprise a photovoltaic panel and at least one structural element. 
         [0012]    In an embodiment of the system, the sheet-shaped material comprises a photovoltaic panel and at least one structural element. 
         [0013]    An object of the invention is likewise attained by a method for assembling laminated structures from sheet-shaped material, the method comprising the steps of:
       providing sheet-shaped material at at least one material input station. Such a material input station may be simply a table or support upon which sheet-shaped material is placed either manually or automatically, may be a rack arrangement in which multiple pieces of sheet-shaped material are mounted, or may simply be a stack of sheet-shaped material. Alternatively, the material input station may be a previous station, such as a work station, in a production line;   collecting said sheet-shaped material from the material input station, which may be merely a table or support, or a more complicated arrangement, and depositing the sheet-shaped material at a work station by means of a robot movable on or about at least one axis, i.e. is a Cartesian, polar, or combined Cartesian and polar robot;   collecting an adhesive applicator from an adhesive applicator rest station by means of the robot;   applying adhesive from said adhesive applicator to the sheet-shaped material deposited at said work station, particularly to the top side of the sheet-shaped material;   returning said adhesive applicator to the adhesive applicator rest station by means of the robot.       
 
         [0019]    In consequence, the same robot is utilised for both collecting and positioning the sheet-shaped material, and for applying adhesive thereto, without requiring that an adhesive applicator be integrated into the robot, or to be permanently attached thereto. Thus, extensive and complicated hoses etc which may become tangled in the robot are no longer needed, and the risk of adhesive dripping from the adhesive applicator is limited to the area between the adhesive applicator rest station and the work station rather than to the entire area of movement of the robot. 
         [0020]    In an embodiment of the method, a further piece of sheet-shaped material is collected by the robot from said at  least one material input station (i.e. the same material input station or a different material input station) and is deposited on top of the already deposited sheet-shaped material at said work station. 
         [0021]    In an embodiment of the method, the laminated structures are building integrated photovoltaics, also known as Structurally Integrated Solar Building Elements, comprising a photovoltaic panel and at least one structural element. 
         [0022]    In an embodiment of the method, the sheet-shaped material comprises a photovoltaic panel and at least one structural element. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    The invention will now be further explained in terms of specific, nonlimiting embodiments illustrated in the figures, which show: 
           [0024]      FIG. 1 : a schematic illustration of a system according to the invention in plan view; 
           [0025]      FIG. 2 : a schematic illustration of a system according to the invention in side view; 
           [0026]      FIG. 3 : a schematic perspective view of a manipulation head of a robot; 
           [0027]      FIG. 4 : a schematic cross-sectional view of an adhesive applicator and its rest station; and 
           [0028]      FIG. 5 : a flow diagram of a method according to the invention.  
       
    
    
     DETAILED DESCRIPTION 
       [0029]      FIG. 1  illustrates schematically in plan view, and  FIG. 2  illustrates in side view, a system  1  for assembling laminated structures according to the invention. The system  1  is based around a robot  10  which may be of any convenient type, i.e. polar, Cartesian, or any combination thereof, movable on or around at least one axis. The system may be easily adapted to various robot types other and may be easily adapted for integration into an inline production system. At least one material input station  11  is provided, here illustrated as one compulsory material input station  11  illustrated with unbroken lines and one optional material input station  11 ′ illustrated in dashed lines, arranged to provide sheet-shaped material. Incorporation of further material input stations is also foreseen as may be required by the particular laminated structure being produced. The material input station may comprise racks, conveyors, may be a previous station in a production line, or may be any other convenient arrangement, such as merely a table upon which material is manually provided. A work station  12  is likewise provided, at which the processing of the laminated structure will take place. This processing takes place by at least positioning sheet-shaped material, applying adhesive to the upper surface thereof, and positioning further sheet-shaped material thereupon. Further stations may also be provided, such as a material alignment station.  
         [0030]    An adhesive applicator  13  for applying adhesive to the sheet-shaped material is provided, which, when not in use, is situated in an adhesive applicator rest station  14 . The adhesive applicator  13  may be a stand-alone unit, or as illustrated in  FIGS. 1 and 2  may be connected via a hose  15  to an adhesive reservoir  16 , this reservoir being associated with means (not illustrated) for forcing adhesive to the adhesive applicator  13  itself, which may be a pump, a gravity feed, a piston situated in the reservoir, or a source of pressurised gas such as air or nitrogen arranged to provide overpressure in the reservoir above the level of adhesive. The adhesive may be a single-component adhesive or a multicomponent adhesive, as is convenient for the materials being laminated together. Such arrangements are known to the skilled person and need not be described further. In the illustrated case, adhesive applicator, hose  15 , and adhesive reservoir  16  constitute an adhesive applicator arrangement  19 . 
         [0031]    The at least one material input station  11 ,  11 ′, the workstation  12 , and the adhesive applicator rest station  14  are all at least partially within the area of reach of the robot  10 , such that the robot  10  can manipulate the sheet-shaped material and the adhesive applicator  13  by means of its manipulation head  20 , described in greater detail below. Control unit  18  controls the robot  10  and the adhesive applicator arrangement  19  so as to assemble the aforementioned laminated structures. Once the structures are assembled, they are removed from the work station  12   either by hand, by the robot  10 , or by other mechanical means (not illustrated). 
         [0032]      FIG. 3  illustrates schematically a nonlimiting example of a manipulation head  20  of the robot  10 . Manipulation head  20  comprises a body  30  provided with a first manipulator comprising a plurality of suction cups  31  arranged for handling sheet-shaped material by application of a negative pressure to the suction cups  31 , as is known. In the present example, six suction cups  31  are provided, however any convenient number is possible. Ancillary equipment such as vacuum hoses and vacuum pumps are known to the skilled person and are not illustrated. As an alternative, electromagnets, mechanical gripping means, or other convenient means may be utilised instead. At one end of body  30  is provided a second manipulator, in this example a pair of opposed grippers  32 , which may be actuated by solenoid, servo, pneumatically, hydraulically, or by any other convenient means, so as to grip and release adhesive applicator  13 . Again, alternatively, electromagnets, suction cups, or other convenient means may be utilised. Adhesive applicator  13  may be provided with features such as grooves, notches, or similar, (not illustrated) for interfacing more accurately and efficiently with the second manipulator. First manipulator and second manipulator, being part of the robot, are controlled by controller  18 . In consequence, by means of the manipulation head  20 , the robot  10  can manipulate both sheet material and adhesive applicator  13  so as to assemble a laminated structure.  
         [0033]      FIG. 4  illustrates a cross-section through adhesive applicator rest station  14  and adhesive applicator  13 . It should first be noted that adhesive applicator  13  may be of any convenient type. Adhesive applicator rest station  14  comprises an essentially box-like structure  42  with an open top, into which adhesive applicator  13  may be at least partially inserted when not in use. Essentially box-like structure  42  may be situated upon a stand  43 , or otherwise supported as convenient. It should be noted that stand  43  may be fixed or mobile, in which latter case the stand  43  may be moved out of the way of the robot  10  when not required. Depending on the type of adhesive used, it may be advantageous to partially fill the box-like structure  42  with an anti-curing, anti-drying or anti-oxidation liquid agent  41 , to prevent adhesive from curing, drying, or oxidising respectively, in which case the box-like structure  42  may be considered as being a liquid agent reservoir. 
         [0034]      FIG. 5  illustrates a flow diagram of a method of assembling laminated structures according to the invention. In a first step  51 , sheet-shaped material is provided at a material input station  11 . In step  52 , the robot collects the sheet-shaped material, and in step  53 , the robot deposits the sheet-shaped material at the workstation  12 . Then, in step  54 , the robot collects the adhesive applicator  13  from the adhesive applicator rest station  14 , and then applies adhesive to the upper surface of the  sheet-shaped material in step  55 . Subsequently, in step  56  the robot returns the adhesive applicator  13  to the adhesive applicator rest station  14 . At the end of these steps, the first layer of the laminated structure being assembled is ready to receive the second layer of sheet-shaped material. Thus, depending on whether more sheet-shaped material has already been provided at the input station or not, either steps  51 ,  52  and  53 , or just steps  52  and  53  are repeated, after which a two-layer laminated structure has been assembled, the deposition of the sheet-shaped material at the workstation in step  53  taking place in the desired alignment upon the previously-deposited sheet-shaped material. If further layers are required, the method continues again with steps  54 - 56  and is repeated until the final layer of sheet-shaped material is deposited in step  53  at the workstation on top of the already deposited layers. 
         [0035]    Once the desired laminated structure has been assembled, it is removed from the work station  12  either manually, by robot  10 , or by other means (not illustrated), for further processing. 
         [0036]    As a concrete example of a laminated structure for which this method is particularly suited, but to which the method is not limited, reference is made to the structurally integrated solar building elements described in the applications WO2011/073303 and PCT/EP2012/076109, herein incorporated by reference in their entirety. In broad  terms, these structurally integrated solar building elements comprise a photovoltaic panel (constituting a piece of sheet-shaped material) laminated with at least one rigid structural element such as an insulating element, for instance a thermal insulating element e.g. of foam (constituting one or more further pieces of sheet-shaped material). In specific embodiments, such structurally integrated solar building elements comprise a laminated structure of several structural and/or insulating and/or barrier elements mounted upon a photovoltaic module. 
         [0037]    Although the invention has been described in terms of specific embodiments, the invention is not to be construed as being limited thereto: the invention is defined solely by the appended claims.