Patent Publication Number: US-2011064553-A1

Title: Method and apparatus for picking up and carrying preforms from bulk transport

Description:
FIELD OF THE INVENTION 
     The present invention finds application in the field of systems for handling and conveying preforms for plastic containers, and namely relates to a method and an apparatus for picking up and carrying said preforms from bulk transport. 
     The applicant hereof has already developed an apparatus and a method for picking up and carrying preforms, but the basic condition to perform the method was having the preforms orderly arranged, e.g. picked up by the preform forming machine. 
     The object of the present invention is to indiscriminately pick up preforms in bulk arrangement on a conveyor belt. In prior art, preforms so arranged are required to be handled and picked up by an operator, who would introduce them into special cardboard containers; with the present method and apparatus, the pick-up process may be automated with the series of checks being performed on the preforms from the conveyor belt, and the acquired parameters may be communicated to a first handling robot, which transfers the object to a rack, whereupon a second anthropomorphic handling robot, having a suction gripping head, loads the objects so arranged and carries them to the appropriate container. 
     The rack comprises means with carriers for aligning the deposited objects and unscrambling the row of preforms to be introduced into the cardboard box, for further space optimization. 
     The advantages achieved by the present method and apparatus may be summarized in terms of operation savings, as the whole process is carried out autonomously by a robotized system which requires no assistance by the operator. 
     These objects and advantages are achieved by the method and apparatus for picking up and carrying said preforms from bulk transport, according to the present invention, which are characterized by the annexed claims. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       This and other features will be more apparent from the following description of a few embodiments, which are shown by way of example and without limitation in the accompanying drawings. 
         FIG. 1 : a general view of the system comprising two handling robots and an optical vision means 
         FIG. 2 : a detailed view of the preform pick-up area on the conveyor belt 
         FIG. 3 : a detailed view of the area on the racks on which the preforms picked up from the belt are laid 
         FIG. 4 : the gripping head of the second handling robot, adapted to pick up and orderly deposit the preforms into an appropriate container. 
     
    
    
     DESCRIPTION OF THE INVENTION 
     Particularly referring to the above figures, numeral  10  generally designates an apparatus for handling and unscrambling preforms  11  arranged in bulk on a conveyor belt  12  or an equivalent conveyor system. 
     The apparatus  10  allows bulk preforms to be picked up, aligned and deposited into the appropriate container, designated by numeral  13  in the Figure. 
     The operation method includes shooting a continuous series of images of the belt with the preforms thereon in bulk, i.e. in random arrangements; images are acquired by a vision system  14  located on a support structure, above the belt and adjacent to the pick-up area for a first handling means  15 ; the method includes taking a snapshot a few instants prior to pick-up and communicating the actual position of the preforms  11  on the belt  12  to said first handling means  15 , to allow unique definition of the proper pick-up position of the detected preform  11 . 
     After pick-up, the preform is intermediately stopped on a rack  16  that has a plurality of housings corresponding to the preform size; once the rack  16  has been loaded, a second handling means  17  having a suction gripping head picks up the preforms from the rack  16  and deposits them into an appropriate container. Each pick-up action by the first means is preceded by a snapshot of the actual situation on the belt, which allows preform mapping and provides correct spatial coordinates for pick-up to occur by means of a vacuum-operated preform gripping system or by grippers or equivalent means. 
     The vision means  14  may be a camera or multiple equivalent systems with lenses. 
     The rack  16  has a sliding compaction abutment  18  for moving all the preforms to the same line and prevent misalignment thereof. 
     The preforms so picked up are introduced into the cardboard box, deposited by the means  17  and laid therein to form two opposite adjacent rows. While reference has been made herein to a cardboard box, the method may be also implemented using instead containers of other materials and shapes.