Abstract:
The fetching device has an arm which captures die-cut blanks located in the magazine of an erecting machine for erecting these blanks to form boxes or the like. The extractor arm is provided with suckers and these suckers are supplied by circuits and. The circuits and are connected to each end of the arm and they are also provided with dispenser-type devive and, respectively, so that they can be active together or separately. The suckers are wholly or partly provided with multifunction three-way valves. These valves are able to allow as many suckers as possible to be selected and used for the operation of extracting each die-cut blank and to isolate the circuits from each other in order to deactivate any suckers which are to be shunted in order to erect said die-cut blanks, for example.

Description:
FIELD OF THE INVENTION 
     This invention relates to an improvement of the device for picking up cardboard cutouts that are stored in a storage location and in particular the storage location of a machine that forms said cutouts. 
     This pick-up device is in the form of an arm equipped with a plurality of suction cups that grip the cutout by means of a vacuum. 
     This invention in fact relates to an improvement of this extractor arm intended to improve its efficacy and make it universally applicable. 
     DESCRIPTION OF THE PRIOR ART 
     Depending on the type of forming machine and in particular depending on the size of the cutouts, the pick-up device can comprise one or more arms equipped with suction cups. In general, this extraction arm is adapted to a cutout model. 
     Due to advances in forming machines, which are increasingly versatile, it is becoming difficult to provide a pick-up device that is entirely effective for extracting all of the models of cutouts that might be formed on a single machine. 
     The operation of picking up the cutouts in the storage location can actually present problems due to the wide variety of formats. 
     The extraction arm cannot grasp the cutouts just anywhere; the suction cups must be positioned in precise locations on the cutout. 
     When the cutout is formed directly with the extraction arm, the suction cups may be operational only on a limited portion of said cutout. 
     Therefore, for certain cutout formats, the number of active suction cups may sometimes be inadequate for properly extracting the cutout that is held at the outlet of the storage location, thereby causing failures and incidents. 
     SUMMARY OF THE INVENTION 
     This invention proposes means that enable the extraction force available on the arm to be used optimally, and the disadvantages of the current pick-up devices to be overcome. 
     It enables devices capable of handling a very wide variety of cutout formats to be proposed with maximum cutout extraction efficacy, i.e. it enables said cutouts to be extracted without failure. 
     In general, the invention enables all situations based on user desires to be managed more easily, even if they involve a multitude of cutout and box formats or even of speeds, while offering a particularly effective extraction of all types of formats. 
     According to the invention, the device for picking up cutouts in the storage location includes—at least one extracting arm that is equipped with suction cups and—two circuits for activating said suction cups, which activation circuits are respectively connected to the ends of said arm, and are also equipped with means enabling them to act together or separately, and said suction cups are themselves equipped, entirely or partially, with multifunctional three-way valves, which valves are capable of enabling a maximum number of suction cups to be selected and implemented for the cutout extraction operation, and for isolating said circuits with respect to one another so as to enable the deactivation of the suction cup(s) to be bypassed for the forming of said cutout, for example. 
     Also according to the invention, the means for activating or inactivating the suction cup feed circuits consist of distributors that enable rapid venting of the circuit in the event of an interruption of the supply to the suction cups supplied by said circuit. 
     According to a preferred embodiment of the invention, the length of the cutout extraction arm corresponds substantially to the dimension of the largest of said cutouts in the case of cutouts for the “American box” construction, and slightly smaller in the case of cutouts for the “wrap-around”-type box construction. 
     Also according to the invention, the suction cup supply circuits are, upstream of the arm, in the form of a double pipe, which pipe cooperates with a clamp system that ensures the attachment and positioning of said pipe on a line that corresponds to the neutral axis of the pivot shaft between the support of said arm and the part, secured to the structure of the machine, to which said support is pivotably connected. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       However, the invention will be further detailed in the following description with the appended drawings, provided for indicative purposes, in which: 
         FIG. 1  diagrammatically shows a pick-up device associated with the storage location of a machine for forming cutouts, and a cutout model also appears in this figure, and in particular a wrap-around-type cutout; 
         FIG. 2  shows the box produced from the cutout shown in  FIG. 1 ; 
         FIG. 3  diagrammatically shows the arm of the pick-up device and the two suction cup supply circuits, which circuits are each equipped with a distributor; 
         FIG. 4  is a partial section of the extractor arm at the level of one of the suction cups in order to show the three-way valve; 
         FIG. 5  is an external view of the extractor arm, at the level of one of the valves; 
         FIG. 6  is a sectional view of the part that supports the extractor arm, showing the suction cup supply circuit installation system. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As shown in  FIG. 1 , the pick-up device  1  is arranged at the outlet of the storage location  2  of a machine for forming cutouts  3 , which cutouts are stored in said storage location. 
     The pick-up device  1  consists of an extraction arm  4  in the form of an elongate bar, and said bar  4  is equipped with a plurality of suction cups  5  that grip, by means of a vacuum, the cutout  3  at the outlet of the storage location  2 . 
     The arm  4  can be moved by suitable means, which are not shown, in order to transfer the cutout  3  at the level of a forming station, for example. 
     The cutout  3  shown in  FIG. 1  is a “wrap-around”-type box cutout. This cutout comprises sides  7 , flaps  8  and an assembly tongue  9 . It can also comprise, as shown in the figure, handles  10  arranged in the small sides, for example, and/or windows  11  on the other sides, which results, after forming, in a box  6  as shown in  FIG. 2 . 
     In addition to the cutouts of which the formats can change, the arm  4  of the pick-up device can therefore be made to handle cutouts  3  that comprise orifices such as handles  10  and/or windows  11 . 
     Opposite these orifices, the suction cups  5  of the arm(s)  4  are ineffective, and, moreover, cause the other suction cups to become less effective due to the leakage that they generate. 
     This problem exists regardless of the number of arms  4 ; with a single arm  4 , certain suction cups  5  may be located opposite windows  11 ; with two arms  4 , certain suction cups  5  may be located opposite handles  10 . 
     To grip and move the cutouts  3 , without failure, the arm  4  has a length that is, for example, approximately the dimensions of the largest format of cutout  3 , and it comprises a large number of suction cups  5 . 
     The length of the arm  4  may correspond to the dimension of the “American box”-type cutouts  3  and it can be slightly smaller if it is a “wrap-around”-type cutout  3 . 
     This arm  4  is also arranged so as to be capable of being easily adjusted to the various possible cases, such as the box shown in  FIG. 2 , i.e. to be capable of gripping cutouts  3  equipped with diverse and varied orifices placed just about anywhere on said cutout. 
     This arm  4 , shown in  FIG. 3 , is connected to a vacuum source  12 , at the level of each of its ends by circuits  13 ,  14 . 
     The circuits  13  and  14  are separated and they each comprise, as also shown in  FIG. 3 , distributors  15  and  16 , respectively, which are supplied by the common vacuum source  12 . 
     These distributors  15  and  16  open or close the circuits  13  and  14 , respectively, and they also enable the suction cups  5  of the circuit that has been closed to be vented so that the suction cup(s)  5  do not remain stuck to the cutout  3 . 
     Preferably, each suction cup  5  comprises its own three-way valve  17 . These valves  17  have a plurality of functions; they enable the suction cups  5  that are operational to be selected, and, in addition, they enable the circuits  13 ,  14  to be separated in a chosen location on the arm  4 , according to the type and format of the cutouts  3 . 
     These valves  17  are arranged at the level of each suction cup  5 . They consist, as shown in  FIGS. 4 and 5 , of a body  18  that comprises three ports. This body  18  is traversed by a conduit  19  and comprises a transverse conduit  20  that is located in the axis of the suction cup  5  and supplies the latter. 
     The supply to each suction cup  5  is provided by means of a ball  21  that is housed in the body  18 . This ball  21  is arranged so as to enable three possibilities:
         supplying the suction cup  5 ,   bypassing said suction cup  5 , i.e. cutting its supply without closing the conduit  19 ,   closing the conduit  19  while supplying said suction cup  5 , i.e. isolating circuits  13  and  14  from one another.       

     The ball  21  is maneuvered very simply, with a screwdriver, for example, that is engaged in the slot  22 , shown in  FIG. 5 . A reference, in the form of an arrow, shows the operator the direction of the ball  21 . 
     The suction cups  5  are connected to one another by pipes  23  and are secured to the arm  4 , which can have a U-shaped cross-section. The arm  4  can also have a plurality of drilled blocks, not shown, which in turn comprise a plurality of suction cups  5 ; it can even consist of a simple, single bar that is drilled over its entire length and on which the various suction cups are implanted directly. 
     The arm  4  enables the cutouts  3  to be picked up in the storage location  2 , and, in particular, as shown in  FIG. 1 , “wrap-around”-type cutouts; this extraction is performed with maximum efficacy because said arm grips said cutout over a large portion of its height. 
     This type of cutout  3 , as shown at the inlet of the storage location  2 , therefore comprises a plurality of sides  7  that are marked l′, l″, L′ and L″, as well as flaps  8  on each side and the adhesive tongue  9  mentioned earlier. 
     As shown in  FIG. 1 , the arm  4  can have suction cups  5  in contact with a plurality of sides of the cutout  3  in order to perform the extraction. Not all of the suction cups  5  are operational; they are operational according to the position of the ball  21 , as shown in  FIG. 1 . 
     In this  FIG. 1 , the suction cup  5 - 1 , which is placed on the l′ side, is bypassed; it is deactivated in order to extract cutout  3  so as not to interfere with the folding of this l′ side during the erecting of said cutout. 
     Also in this example, the suction cups  5 - 2  and  4  are active, as are suction cups  5 - 5  to  7  and suction cup  5 - 9 . 
     Suction cups  5 - 3  and  5 - 8  are inactive and not supplied; but they leave the corresponding circuits open. 
     It is at suction cups  5 - 4  or  5 - 5  that the separation of the two supply circuits  13  and  14  takes place in order to enable, after extraction of the cutout  3 , the deactivation of the suction cups  5 - 5  to  9 ; this deactivation of the suction cups  5 - 5  to  9  is essential for the erecting of said cutout  3 . 
     In  FIG. 1 , the separation of circuits  13  and  14  is performed at the valve  5 - 4 . This valve  5 - 4  enables the corresponding suction cup to be supplied, but it closes circuit  13  and, consequently, circuit  14 . 
     The operator intervenes, when changing the cutout  3  formats, on the various valves  17 , and in particular the balls  21 , in order to active and/or deactivate the suction cups  5  and in order to form two sectors: a sector P, which can be qualified as the main sector, corresponding to the L′ side of said cutouts and which is assigned both to the extraction and the erecting thereof, and a sector S, which is assigned only to the extraction of the cutouts  3 . 
     The activation of each sector P and S is performed automatically by acting on the distributors  15  and  16 ; the two distributors  15  and  16  simultaneously supply all of the suction cups  5  previously selected for the cutout  3  extraction operation, and then the distributor  16  closes the supply of the circuit  14  and opens said circuit  14  to deactivate the suction cups  5 - 5  to  9 , freeing sides l″ and             of the cutout  3 , which are intended to be folded.
     The two circuits  13  and  14  that supply the suction cups  5  consist of pipes that accompany the arm  4  in its pivoting movement, for example. 
       FIG. 6  is a sectional view of the part  31  that is secured to the structure of the cutout  3  forming machine, and it is on this part  31  that the arm  4  is pivotably connected by means of its support  32 . 
     The circuits  13  and  14  are combined in one pipe  34 , which is a double pipe. This pipe  34  is snapped into a clamp system  35 , and these clamps are arranged on the part  31  and on the support  32  of the arm  4 . 
     This assembly has the advantage of being simple; it also enables the pipe  34  to be installed by the pivot shaft located between the support  32  of the arm  4  and the part  31 , which is secured to the structure of the machine. 
     The deformation of this pipe  34  is thus better controlled; it is more regular and the risks associated with friction with other parts are eliminated.