Abstract:
An installation includes a machine ( 2 ) for packaging products ( 8 ) and of a robotic palleting station, both arranged in a same enclosure ( 1 ) that is provided with a door ( 7 ) that offers access to the palleting station. The installation includes a device which limits the range of movement of the robot ( 15 ) in the closed enclosure ( 1 ) in order to concentrate the displacements of its gripping head ( 17 ) in a restricted space which does not overlap with a safety space, which is defined according to a minimum distance measured from the immaterial barrier located in the enclosure in the vicinity of the door ( 7 ). The limiting device includes an electric cam that limits, under the control of the steering control of the robot, the amplitude of the movement of the robot ( 15 ) around its main axis and reduces its movement speed.

Description:
FIELD OF THE INVENTION 
     This invention relates to an installation which comprises, in a combined manner, a robotic station for palleting carton cases and a packaging machine which converts said cases and carries out their filling with products that have been conditioned beforehand. 
     DESCRIPTION OF THE PRIOR ART 
     Generally, robotic installations are very dangerous for the operators who need to get close to the robot. 
     As such, for this type of robotic palleting installation, the operations of removing full pallets and inserting empty pallets are generally carried out by using an automatic type of conveyor; however, this type of installation usually requires a large ground surface area. 
     For compact installations, such as that which is the object of the invention, wherein the robotic palletizer is combined directly with a machine that carries out the packaging of products, it is conventional to secure the installation, i.e. to stop the robot, when a manual intervention must be carried out by an operator, such as the removing of a full pallet of cases or such as the inserting of an empty pallet. The robot stoppage occurs during the entire time required for these operations; but the stopping of the palleting robot also implies a stopping of the packaging machine to which it is associated. 
     These stoppages of the packaging machine cause production losses and they can also disturb the production upstream, such as is carried out, for example, during labelling or placing products into the next container. 
     This invention improves this type of compact installation which combines a packaging machine and a palletizer; it makes it possible in particular to offer a high degree of safety for the operator who is responsible for intervening operations with the palleting station and, above all, it allows this intervention of the operator without requiring a stoppage of the function(s) which are immediately upstream, while also retaining the reduced ground surface area required for the installation. 
     SUMMARY OF THE INVENTION 
     The installation according to the invention is comprised of a packaging machine for products and of a robotic palleting station of which the robot takes the cases filled with said products at the output of said packaging machine in order to arrange them, according to an appropriate diagram, by means of a gripping head, on a pallet that is adjacent to said exit, said packaging machine and said palleting station being arranged in the same closed enclosure which is comprised of lateral walls, a rear wall wherein penetrates, in particular, the cartons used for the converting operation of said cases, and a front wall which is provided with a door offering the access to said palleting station, said installation comprising means which limit the range of movement of said robot in said closed enclosure in order to concentrate the displacements of its gripping head in a restricted space which does not overlap onto the safety space which is defined at least according to a minimum distance measured using a means for detecting intrusion which is located on the opening of the access door to the palleting station, said means for limiting the range of movement of the robot are comprised of:
         a cam, of the electric type, which ensures that the robot does not exit the authorised work zone and limits, in particular, the amplitude of its movement around its main axis no.  1 ,   a member, of the switching type, which takes into account a request for intervention of the operator for access to the palleting station in order to remove the pallet full of cases and to replace it with an empty pallet,   a steering control of said robot, of the automatic type, which manages said request from the operator in order to activate said electric cam and operate said robot in said restricted space contained inside the authorised volume of movement and programmed on said steering control.       

     Still according to the invention, the restricted space wherein the robot intervenes comprises at least one buffer zone which is arranged as a platform in order to allow for a temporary setting down of cases of products produced by the packaging machine, said platform can, in particular, be accessed by said robot, during the operation of extracting the pallet that is ready and during the setting into place of a new pallet to be filled. 
     According to another arrangement of the invention, the installation comprises, on the steering control of the robot, means for modifying the speeds of movement of the robot and in particular in order to reduce said speeds during its operating phase in the restricted space which is allocated to it. 
     Still according to the invention, the steering control of the robot also manages all of the movements of said robot while still ensuring that it does not exit the work zone which is programmed, i.e. this steering control of the robot comprises means for defining work spaces wherein the robot is authorised to operate as well as means for causing its immediate and total stoppage if it leaves these authorised operating spaces. 
     According to another arrangement of the invention, the installation comprises a sensor which is associated to the access door to the pallet, said sensor authorising, by the intermediary of the steering control of the robot, the continuation of the activity of the robot in its restricted space if the operator has requested access to the palleting station, or causes the immediate and total stoppage of said installation in the event of the absence of an access request or in the case where said access door is manoeuvred before the receiving of the authorisation for opening which is given by the intermediary of a lighted indicator associated to the switch. 
     Still according to the invention, the installation comprises, on the access door to the palleting station, a system for detecting an intrusion of the operator or other, in the safety space, said system for detecting, of the immaterial barrier type, is arranged in such a way as to allow the introduction of an empty pallet and in such a way as to cause the immediate and total stoppage of the installation in the event of intrusion of anyone in said safety space. 
     According to another arrangement of the invention, the installation comprises, associated to the immaterial barrier, means for inhibiting the latter, said means are comprised of photoelectric cells in order to allow for the extraction of the full pallet without causing the immediate and total stoppage of said installation. 
     Still according to the invention, the installation comprises means for signalling the end of the preparation cycle of a pallet with the cases of products that are exiting the machine for conditioning; said means are in the form of a lighted device. 
     According to another arrangement of the invention, the installation comprises, in the restricted space, one or several additional devices which can be accessed through the robot such as, for example, a case labelling station and/or a retrieval and transfer zone for cases intended for scrap, said retrieval zone being provided with a conveyor belt in order to evacuate said scrap towards the exterior of the installation. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       But the invention will also be detailed using the following description and the attached drawings, provided for the purposes of information, and wherein: 
         FIG. 1  is a general schematic view in perspective of an installation according to the invention which combines a machine for conditioning products and a palleting station; 
         FIG. 2  is a schematic view on the installation plane according to the invention; 
         FIG. 3  is a partial side view of the installation showing the palleting station and the means for anti-intrusion, in the form of immaterial barriers. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The installation shown in  FIGS. 1 and 2 , comprises, brought together in an enclosure  1  which is closed, a packaging machine  2  for products and a station for the pallet  3  where the automatic palleting operation takes place. 
     The enclosure  1  is closed by lateral walls  4 , a rear wall  5  and a front wall  6  which comprises a door  7  in order to provide access to the pallet  3  which is located at the palleting station. 
     The machine  2  for conditioning is, for example, a machine of the type of that described in FR 2 907 100. It is fed with products  8  regularly by means of a conveyor  9 , shown in  FIG. 2 , which introduces said products  8  by the rear wall  5  of the enclosure  1 . This machine  2  further comprises a bin  10 , also shown in  FIG. 2 , which makes it possible to supply it with carton blanks for the converting operation of the cases  11 . 
     The products  8  are positioned in the cases  11  by the machine  2  and these cases  11  exit from said machine  2  onto a conveyor  12  which extends longitudinally in the enclosure  1 . 
     The palleting station can comprise a frame  13 , shown in  FIG. 2 , which makes it possible to centre the pallets  3  in a zone which is located across from the door  7 , and on the side of the conveyor  12 . 
     A robot  15  is arranged behind the palleting station, on the side of the packaging machine  2 . This robot  15  is mounted on a base  16  which is placed on the ground or which is integral with the general chassis of the entire installation. This robot  15  comprises several arms and it pivots around its main axis no.  1  which is a vertical axis, said axis no.  1  corresponding to the first axis in relation to base  16 . 
     This robot  15  is provided with a gripping head  17  which is located at the end of its different arms. This gripping head  17 , provided with suction cups  18 , captures the cases  11  in order to arrange them according to an appropriate diagram on the pallet  3 . 
     The volume V in the enclosure  1 , wherein the robot  15  is authorised to move, is programmed in a steering control  20  of said robot  15  and this control, of the automatic type, is incorporated into said enclosure  1 . 
     All of the installation operates with this steering control  20  of the robot  15  which is responsible, with the appropriate programmes, for operating the robot  15  and, in particular, for allowing for the operation of palleting of the cases  11  according to a diagram that is adapted to said cases and to the pallet  3 . 
     This robot  15  can also interact with additional equipment such as, for example, a conveyor  22  arranged at the downstream end of the conveyor  12 , said conveyor  22  retrieving any scrap and transferring it towards the exterior of the installation. 
     The robot  15  can also interact with a device  23  that carries out the labelling of the cases  11  before arranging them on the pallet  3 . 
     The packaging machine  2  operates continuously; it operates at the speed at which it is supplied with products  8 . The robot  15  provides for the palleting of the cases  11  as they exit from the machine  2 ; its gripping head  17  of the cases  11  circulates in a volume which is programmed in the steering control  20  of the robot  15  and this volume V is included within the enclosure  1  in order to place said cases  11  according to the distribution diagram provided for the pallet  3 . 
     When the pallet  3  is full, the robot  15  is programmed to continue to operate and to handle the cases  11  that continue to exit from the packaging machine  2 . 
     The installation comprises a buffer zone which includes a platform  25  arranged, for example, above the packaging machine  2 . The buffer zone makes it possible for the robot  15  to temporarily set down the cases  11 , while the operator intervenes to remove the pallet  3 , which is full, and to install a new pallet at the palleting station. 
     In order to allow the operator to intervene in complete safety, the robot  15  comprises means which make it possible to limit the maximum amplitude of its movements in the volume V. The means for limiting the amplitude includes an electric cam, and makes it possible to define, authorise and/or prohibit sectors for the moving of the robot  15  around its main axis no.  1 . 
     The steering control  20  of the robot  15  manages, by the intermediary of this electric cam, all of the movements of said robot  15  while ensuring that it does not exit from the work zone which is programmed, i.e. this steering control  20  comprises means for defining the work spaces wherein said robot is authorised to operate as well as means for causing its immediate and total stoppage if it leaves these authorised operating spaces. 
     In  FIG. 2 , note that the robot  15  has a major sector S of intervention which corresponds to the horizontal projection of the volume V. This major sector S is the sum of two sectors Sr and Si:—the sector Si which corresponds to a space wherein the presence of the robot  15  can be prohibited momentarily and—the sector Sr which corresponds to a restricted space wherein said robot  15  can operate according to a programme that is adapted to the situation, as explained hereinafter. 
     The prohibited space for the robot  15 , which corresponds to the sector Si, extends inside sector S starting from the frame of the door  7 . This prohibited space corresponds to a minimum volume which is defined by a distance measured at least using means, detailed further on, which make it possible to detect an intrusion in the enclosure  1 ; these means of detection are located beyond the door  7 , inside of said enclosure  1  and this minimum distance is of a magnitude of 50 cm in the installation such as is shown in the figures; this distance can vary according to the type of robot and in particular according to the stopping distance of said robot during an emergency stop. 
     During normal operation, when the door  7  is closed, the robot  15  has full latitude to operate within the space that corresponds to the sector S. 
     When the pallet  3  is full, and when the operator intervenes in order to, on the one hand, evacuate this full pallet and, on the other hand, position a new pallet  3 , the intervention space of the robot  15  is limited to the sector Sr which is the restricted sector, i.e. a sector which allows the robot  15  to grasp the cases  11  at the output of the machine  2  and to place them in the temporary storage zone, on the platform  25  which doubles as a buffer. 
     In this sector Sr, the steering control  20  of the robot  15  can be programmed so that the latter operates at speeds which are less than those that it uses in the sector S, i.e. in the sector which corresponds to its normal operating cycle. 
     The sector Si corresponds, for the robot  15 , to the space which is secured and wherein there is a danger for the operator, in particular when his intervention to remove the pallet which is full and to introduce a new pallet  3 . 
     In order to carry out this operation of removing a full pallet and introducing a new pallet  3 , the operator is first of all informed. Means, comprised of a warning indicator  27 , of the lighted or other type, installed on the enclosure  1 , informs him that the pallet is full. 
     In order to carry out this operation of extracting the full pallet and in order to install a new pallet  3  in the frame  13 , the operator has a member of the switch type  28 . This switch  28  allows him to transmit to the steering control  20  of the robot  15 , his intention to access the palleting station. 
     In this case, the robot  15  completes its task in progress and will position itself in the sector Sr. From this point, through the steering control  20 , the robot  15  is confined to this sector Sr, i.e. to the restricted sector which allows it, in particular, to take the cases  11  at the output of the machine  2  and to set them down temporarily on the platform  25 . 
     The working speed of the robot  15 , during the normal palleting cycle, is sufficiently high in order to allow it to resume later the cases  11  stored on the platform  25  and to arrange them on the pallet with the other cases which are exiting from the packaging machine  2 . 
     On the other hand, as soon as the robot  15  is located in the sector Sr, a lighted signal of the lighted indicator type, associated to the switch  28 , informs the operator that all of the safety conditions have been satisfied and that he is authorised to open the door  7 . 
     Still for the safety of the operator, the installation comprises a sensor  29  which interacts with the door  7  in order to inform, the steering control  20  of robot  15 , that said door is in closed position or in open position. 
     This sensor  2  makes it possible to secure the installation if the door  7  is manipulated by any person, without having been authorised beforehand, i.e. before the lighted indicator of the switch  28  is lit. 
     In light of the fact that the robot  15  operates in its restricted space Sr when the door  7  is open, an immaterial barrier  30 , shown in  FIGS. 2 and 3 , makes it possible to secure the installation, i.e. to stop it, if the operator or another person penetrates into the enclosure  1  via the door  7 . 
     This barrier  30  is comprised of ramps  31  and  32  which are vertical. These ramps comprise photoelectric cells and they are arranged in the enclosure  1 , at a distance from the door  7 , behind the frame of the latter. More preferably, the distance that defines the prohibited space for the robot  15 , when the door  7  is open, is measured from the immaterial barrier  30 ; this distance is, for example, of a magnitude of 50 cm as indicated hereinabove. 
       FIG. 3  shows the location of the immaterial barrier  30 , on the height of the opening of the enclosure  1 . The ramps  31  and  32  of this barrier  30  are arranged at a certain distance from the ground, of a magnitude of 30 cm, for example; said barrier  30  is located in fact at a level which is above the upper level of the pallet  3 , when it is empty of course, in such a way as to allow for the introduction of this pallet  3  into the frame  13 , at the palleting station, without the risk of cutting the beams of the cells of said immaterial barrier  30 . 
     In order to improve the safety, this barrier  30  can also comprise a first active zone  33  which extends to the height corresponding to that of the full pallet and a second zone  34 , also active, but permanently. 
     The zone  33  of the immaterial barrier  30  can be placed into an inactive situation, the time needed to remove the full pallet. Means make it possible to inhibit this zone  33  of the barrier  30 ; they are comprised, for example, of a pair of cells  35 ,  36 , which are located inside the enclosure  1 . 
     At the time of its exit, the full pallet cuts the beams of the cells  35  and  36  for inhibition before those of the barrier  30 , which results, by the intermediary of the steering control  20 , in the deactivating of said barrier during the exiting phase of said full pallet. 
     The inhibition of the immaterial barrier  30  is cancelled as soon as the full pallet is longer across from the beams of the cells of said barrier  30 . 
     Introducing a new pallet  3  at the palleting station is carried out without cutting the various beams as said empty pallet passes under the level of the various beams. 
     Still in reference to  FIG. 3 , note the presence of a sensor  37  which makes it possible to inform the steering control  20  of the robot  15  of the presence or of the absence of a pallet at the palleting station. 
     After the extraction of the full pallet and the setting in place of an empty pallet, the operator closes the door  7  and resumes the normal cycle of the robot  15  with another intervention on the switch  28 . After validation of the closing of the door  7  by the sensor  29 , the robot  15  resumes, under the control of the steering control  20 , its activity throughout all of the sector S, i.e.: gripping cases  11  on the conveyor  12  at the output of the packaging machine  2  and/or gripping cases stored on the platform  25  in light of their palleting.