FR2867452A1 - METHOD AND DEVICE FOR SHAPING AND REMOVING HIGH PURPOSE OF A PACKAGING COVER ON A PALLETIZED LOAD - Google Patents

Abstract

A device for shaping and depositing a packaging cover (HO) on a palletized load (CH) comprises at least one positioning member (13, 14) arranged between a reel (11, 12) for storing the sheath 17, and an accumulator element (20) for holding the sheath (17). The positioner member (13, 14) is movable in height in the preparation station (10) while being coupled to an actuator (13a, 14a) so as to move the sheath (17) between a standby position, and a high engagement position of the heat-sealed connection (19) in the accumulator element (20).

Description

Method and device for shaping and depositing at high speed a

  packaging cover on a palletized load.

  TECHNICAL FIELD OF THE INVENTION The invention relates to a method and a device for shaping and removing a packaging cover on a palletised load, said cover being prepared from a material sheath. flexible plastic wound on at least one storage spool, the method comprising: transversely welding the sheath at its free end to create a heat-sealed connection held in a down position by at least one positioner member; storing on a transfer device; accumulating a predetermined length of sheath to form said cover, - resume the lower free end, and down the cover around the charge to be packaged, keeping it spaced by its four corners.

  State of the art EP-A-1060988 discloses a device for overpacking a palletized load by means of a cover prepared from a bellows duct wound flat on a storage spool. A robotic gripper comprises a motorized accumulator roller on which is wound a portion of the sheath, a transfer arm of the roller towards the filling station, and a mechanism of separation of the cover during the downward movement around the load. The sheath previously welded in the transverse direction, is held in vertical position with the bellows solicited opening by a positioning member, which is fixed and disposed with the coil in the vicinity of the ground. The transfer arm of the robot is carried by a slide movable in vertical translation on the frame. The arm of the robot is thus animated with a first horizontal movement of translation during the transfer, and a second downward movement to prepare the cover by welding and cutting after its winding around the accumulator roller. This second vertical movement of the arm is essential, since the positioner member of the sheath is fixed. This combined movement of the robot lengthens the time of preparation and removal of the cover, and limits the packaging rates of the machine.

  EP-A-395919 relates to a machine for packaging a load palletized by means of a heat-shrinkable film, comprising four vertical bars 1 o equipped with gripping tongs of the film that can move up and down in the frame, a annular shrink oven, a pair of horizontal crosspieces and two trolleys that can move horizontally along the sleepers. The bars come closer when the carriage moves to the dispensing section, and move apart as the carriage moves over the load to be packaged. This mechanism also ensures the houssage. The kinematics of such a machine does not reduce packaging rates, and is limited to loads of low heights.

  OBJECT OF THE INVENTION A first object of the invention is to improve the method of preparing and removing a cover on a palletised load, to accelerate the packing cycles and to increase production rates.

  The packaging method according to the invention is characterized by the following intermediate steps: vertically driving the heat-sealed connection to a high position by the positioner member movable in height to an altitude situated above the upper face of the load, and horizontally moving the transfer and accumulation device in a single horizontal movement directed orthogonally with respect to the displacement of the positioner member to ensure the recovery of the lower end of the cover.

  During the return run of the transfer and accumulation device, the positioner member is moved to an intermediate waiting position located just before said upper film-engaging position in the accumulator element. This results in a time gain corresponding to the duration of the rise stroke of a positioner member between the low position and the intermediate waiting position.

  To make the cover, it is possible to use a tubular sheath with or without bellows, and made of heat-shrinkable plastic or stretchable plastic.

  1 o The vertical displacement of the sheath upwards by driving the positioner member, and the horizontal transfer of the wrapped cover on the accumulator member, cause two translational movements independent of one another, unlike the movement combined robot according to document E PA-1060988. This results in an acceleration of packaging cycles, and an increase in production rates.

  A second object of the invention is to provide a machine for shaping and removing a packaging cover on a palletized load, allowing high production rates, and can use either a heat shrinkable or stretchable plastic sheath.

  The machine comprises a transfer and accumulation device comprising an accumulator element on which is wound a portion of the sheath, and a spacing mechanism of the open end of the sheath after transfer to the filling station. According to the invention, the positioner member is movable in height in the preparation station by being coupled to an actuator, so as to move the sheath between a low waiting position, and a high position of engagement of the heat-sealed bond in the accumulator element. The transfer and accumulation device is pivotally mounted on a vertical axis of an actuating arm to position the heat-sealed connection parallel or perpendicular to the largest face of the load. The positioner member is guided in vertical translation between the two low and high positions by a guide rod or slide secured to a support.

  Other characteristics may be used in combination: the support of the two positioner members is mounted on a bridge fixed to the frame above the ground; - The support is adjustable on a horizontal crosspiece integral with the frame, and is provided with two positioners may be alternately facing the accumulator member by a horizontal translational movement of the support; - The positioners maintain sheaths from two superimposed coils, whose axis extends parallel or perpendicular to the handling conveyor; the removal arm is provided with shaping and pinching fingers for the recovery at the four corners of the open portion of a cover of heat-shrinkable plastic film; - The removal arm is provided with pleating fingers and stretching for successively the accordion pleating of the stretch plastic film cover following the rotation of motorized rollers, followed by a transverse stretching at the four angles before the descent around the charge.

Brief description of the drawings

  Other advantages and features will emerge more clearly from the following description of an embodiment of the invention given by way of non-limiting example, and represented in the accompanying drawings, in which: FIGS. 1 and 2 are schematic views of the preparation station of the cover according to the invention, with two positioners respectively in the waiting position, and in the displacement position of one of the positioners to the accumulator element; FIGS. 3 to 9 show schematic views of the complete device with the preparation station and the filling station making use of a heat shrinkable jacket removal frame, the device being illustrated in different phases of preparation, transfer and removing the cover; - Figures 10 to 18 show the following phases of operation of the device with a setting frame adapted to a stretchable sheath; - Figure 19 is a side view of the preparation station of the cover; - Figures 20 to 22 show the steps. successive return of the accumulator roller and the balance arms for taking the film at high rate; - Figure 23 is an identical view of the station. preparation of Figure 1, with a variant of the accumulator member.

  Description of a Preferred Embodiment

  Referring to Figures 1 to 2, a preparation station 10 of a packaging cover, comprises a pair of coils 11, 12 for storing a plastic sleeve 17, a pair of positioners 13, 14 for opening and positioning the sheath 17 from each coil 11, 12, a transfer and accumulation device 15, and welding and cutting means 16 to form from each coil 11, 12, a cover HO of a predetermined length and wound on the transfer and accumulation device 15.

  The packaging sheath 17 is formed by a plastic film with double V-bellows, and folded flat after winding around each cylindrical coil 11, 12. This type of sheath is described in detail in EP-A-1060988. It is then unrolled, passes over guide rollers 18, 18a, and is held in a vertical position with the bellows urged to open by the positioner members 13, 14. Previously, the middle portion of each sheath 17 has been welded transversely to its free end to obtain a sealed bottom thanks to the formation of a heat-sealed connection 19.

  The casing 17 with bellows can also be replaced by a simple tubular sheath without bellows, and also folded flat on the reels 11, 12.

  The film of the sheath 17 may be of heat-shrinkable plastic or stretchable plastic. Figures 3 to 9 show an application with heat-shrinkable film, while Figures 10-18 illustrate another application with stretch film. The steps of the process of forming the HO cover at the preparation station 10 are identical, regardless of the heat-shrinkable or stretchable nature of the film used.

  The transfer and accumulation device 15 comprises an accumulator element 20 and a spacing mechanism 21 with four swinging arms 22. The accumulator element 20 is provided as an example of a motorized rotary roller 23 on which is wound a portion of the sheath 17, which is held by a retaining clip 24 integrated in the roller 23. The four rocking arms 22 of the spacer mechanism 21 are equipped with gripping tongs 25, arranged at each end to guide and grasp the sheath 17.

  In the rest position (Figure 1) and during the winding phase of a sheath 17 around the roller 23 (Figures 2 to 4), the four rocker arms 22 are in the retracted position. The rocking arms 22 are actuated to the remote position (FIGS. 5 and 6) by pivoting by means of pneumatic cylinders acting during the transfer to the stuffing station 26.

  The welding and cutting means 16 comprise a welder with two movable jaws 27 capable of moving in a horizontal plane symmetrically with respect to the positioner members 13, 14. The upper part of the welder comprises a linear cutting device 28 equipped with a straight cutting blade actuated by a jack.

  The transfer and accumulation device 15 is pivotally mounted about a vertical axis 29 for positioning the heat-sealed connection 19 of the cover HO parallel to or perpendicular to the largest face of the load CH, which generally has a parallelepiped shape. The displacement of the cover HO between the preparation station 10, and the stuffing station 26 operates exclusively in a horizontal plane via a transfer carriage 30 carried by an actuating arm 31, which is arranged at the top of a 32 vertical frame.

  The positioners 13, 14 are movable in the height direction, so as to move the heat-sealed connection 19 of the cover from a low position (Figure 1) to a high position (Figure 2) for the introduce in the retaining clip 24 of the accumulator roller 23. The high position corresponds to an altitude substantially equal to or greater than the level of the upper face of the load C H being on the side of the filling station 26.

  The actuators 13a, 14a of the positioners 13, 14 are guided in translation by vertical rods 13b, 14b integral with a support 33, which is on a horizontal bridge 34 fixed to the frame 22. The support 33 can slide along a horizontal crossbar arranged slightly above the bridge 34, so as to alternately position one of the positioners 13, 14 facing the retaining clip 24.

  The welding and cutting means 16 are interposed at an intermediate level between the gripping tongs 25 of the rocking arms 22 and the upper ends of the rods 13b, 14b of guide.

  The palletised CH load is carried in the filling station 26 by a table 36 chain or roller. A removal arm 37 of the HO cover can slide vertically along the frame 32, and is provided with shaping and pinching fingers 38 for the recovery of the open portion of the HO cover at the four corners when removing the load. CH (Figures 3 to 9). These fingers 38 are arranged to receive a HO cover of heat-shrinkable plastic film.

  The charge CH coated with its HO cover is then moved to a downstream station, which is equipped with a hot air heating frame for heat shrinking of the cover HO on the load CH.

  The operation of the overwrapping device with a heat-shrinkable sheath 17 is illustrated in FIGS. 1 to 9: In FIG. 1, the two positioner members 13, 14 are waiting in the low position, ensuring the horizontal holding of the heat-sealed connection 19 two sleeves 17 from the two coils 11, 12. The jaws 27 for welding 2867452 above the rods 13b, 14b are spaced from each other, and the retaining clamp 24 of the accumulator roller 23 is open to release the gripping zone of the heat-sealed connection 19 of the sheath 17 selected. The support 33 is moved to the right so as to place the positioning member 13 opposite the retaining clip 24. The rocking arms 22 are in the retracted position, and the actuating arm 31 is on the right above the preparation station 10 of the packaging cover. In this production standby position, the internal volume of the two sleeves 17 is protected by the associated heat-sealed connection 19, avoiding any penetration of ambient dust.

  In Figure 2, the positioner member 13 associated with the first coil 11 is moved to the upper position above the upper level of the load to be packaged. In its displacement in translation upwards, the positioner member 13 causes the unwinding of the coil 11, and causes the heat-sealed connection 19 in the retaining clamp 24. The gripping tongs 25 of the four arms 22 are spaced, as well as the welding jaws 27. The other positioner member 14 remains stationary in the low position, without unwinding the coil 12.

  In the step of Figure 3 is involved the winding and storage of a predetermined length of sheath 17 around the motorized roller 23 which rotates in the direction of clockwise. The positioner member 13 descends towards the lower position, and the gripping tongs 25 of the four arms 22 engage between the bellows of the sheath 17. At the filling station 26, a previous load CH is completely enveloped by a cover HO, which has been previously prepared and transferred by the transfer and accumulation device 15. This packaged charge CH is then discharged on the table 36 to a downstream station where the heat-shrinking operation is carried out. It is also possible to provide a hot-air shrink frame around the load for heat-shrinking in the foaming station as described in EP-A-1060988.

  In FIG. 4, a new load CH is brought onto the table 36 to be wrapped by the cover in preparation on the roll 23 of the station 10. The depositing arm 37 has been raised in translation above the load CH to be packaged , with transverse refocusing of the recovery fingers 38. The welding jaws 27 approach each other to make a new heat-sealed connection 19 which will be used to make a new cover.

  In Figure 5, the cutting device 28 has been actuated to cut the cover HO to the desired length, while the jaws 27 remain in close position. The actuating arm 31 is moved horizontally to the left above the stuffing station 26, and the translation of the transfer carriage 30 ensures the exact positioning of the roll 23 above the deposition arm 37. The four 1 o arms rockers 22 are actuated to the spread position to cause. the opening of the lower free end of the HO cover. This end of the HO cover is then taken by the fingers 38 of the removal arm 37, which are spaced to be placed under the clamps 25 of the arms 22. In this step, the roller 23 is motorized in the direction of unwinding.

  In Figure 6, the retaining clip 24 of the roller 23 is opened to release the heat-sealed connection 19 of the cover HO. The disengagement arm 37 begins its descent movement to gradually wrap the load CH with the cover HO, while the arms 22 remain in the spread position maintaining the cover spread by its four corners. The welding jaws 27 and the cutting device 28 return to the rest position.

  In FIG. 7, the cover HO has left the gripping tongs 25 of the arms 22, and the removal arm 37 is coming down from the load CH in the stuffing station 26. The actuating arm 31 and the carriage 30 return to the right above the preparation station 10, and the arms 22 are actuated to the retracted position. The support 33 is moved in translation to the left along the crosspiece 35, so as to select the positioner member 14 associated with the second coil 12. The positioner member 14 can thus be actuated upward without waiting for the final return. of the transfer and accumulation device 15.

  In FIG. 8, the load CH is completely packed by the cover HO, and the positioning member 14 is in the raised position, causing the insertion of the heat-sealed connection 19 in the retaining clip 24 of the accumulator roll 23. The other positioner member 13 is waiting in the low position.

  In FIG. 9, the removal arm 37 is being raised, and the device 15 coils and stores a predetermined length of sheath 17 around the rotary roller 23. The positioner member 14 descends during this winding phase of the sheath.

  The following sequence of operation illustrated in FIGS. 10 to 18 is carried out with a stretch film sheath. In this case, the members of the preparation station 10 of the HO cover are identical to those of FIGS. 1 to 9. The structure of the deposition arm 37 in the filling station is different, and instead comprises shaping fingers and nip 38, pleating and drawing fingers 39 associated with motorized rollers 40. In contrast to the heat-shrinkable film, the introduction of a stretchable sheath does not require a source of heat to heat-shrink, because it is sufficient to mechanically stretch beforehand the material of the plastic film in the horizontal transverse direction before enveloping the palletized load to be packaged. After removal of the stretched cover from the load, the tightening of the stretch film material naturally takes place by elasticity, which firmly holds the cover around the load. Each finger 39 is mounted on a control member 41 driven by an actuator of the cylinder or geared motor type in a direction substantially coincident with the diagonal of the load CH.

  In FIG. 10 corresponding to the following sequence of FIG. 9, the positioning member 14 continues its downward movement towards the low position, and a new load CH to be packaged is brought onto the table 36 of the stuffing station. The removal arm 37 is raised in translation above the load CH, with transverse refocusing of the pleating fingers 39. The rollers 40 are spaced from the fingers 39, and the sheath 17 from the coil 12 is wound around the roller 23 accumulator.

  In FIG. 11, the welding jaws 27 approach one another to make a new heat-sealed connection 19, and the roller assembly 23 and rocker arms 22 remain immobilized above the jaws 27 until they are closed. the intervention of the cutting device 28.

  In FIGS. 12 and 13, the actuating arm 31 is moved horizontally to the left above the stuffing station 26. The transfer carriage 30 also moves in the same direction to ensure the exact positioning of the roller 23 over 37. The four rocking arms 22 are actuated towards the spaced position to cause the opening of the lower free end of the cover HO. The fingers 39 of the deposition arm 37 are spaced 1 o to be placed under the clamps 25 of the rocking arms 22.

  FIGS. 14 and 15 show the pleating and accumulation phase of the cover HO on the lower part of the fingers 39. The accordion pleating of the cover HO takes place following the rotation of the motorized rollers 40 which are in contact with the four fingers 39.

  FIG. 16 shows the transverse stretching of the creased HO cover as a result of the maximum spacing of the control members 41 of the fingers 39. The rollers 40 do not rotate during this transverse stretching phase of the cover HO, which is stretched with an elongation rate greater than 30%.

  In Figures 17 to 22, the descent movement of the deposition arm 37 causes the progressive unfolding of the HO cover around the load CH. The actuating arm 31 and the carriage 30 return to the preparation station 10, and the arms 22 are actuated to the retracted position. At the beginning of the return stroke (FIG. 17), the two positioner members 13, 14 are both in the low position. The continued return travel of the accumulator element 20 is effected by a transverse sliding movement (FIG. 18), and the rocking arms 22 pass on either side of the positioner members 13, 14 (FIG. 19). The positioner member 14 can thus be moved upwards to a waiting position (FIG. 20), located just before the end position. When the accumulator roller 23 and the retaining clip 24 come opposite the film held by the positioning member 14 in the intermediate waiting position (FIG. 31), it is sufficient to mount the positioner member 14 towards the up position (FIG. 22) 12 2867452 introduction of the heat-sealed connection 19 of the film in the retaining clip 24. This overtravel between the intermediate position of waiting and the high position is very short, and allows to improve the rate of the machine of packaging.

  The time saved is the duration of the rise stroke of a positioner member 13 or 14 between the low position and the waiting intermediate position.

  Fig. 23 shows a variant of the accumulator element 20 of the device 15, 1 o wherein the rotary roller 23 is replaced by a movable roller system.

  Instead of using a single transfer and accumulation device 15 as shown in FIGS. 1 to 22, the packing rate of the machine can be further increased by making use of two alternating movement accumulator systems.

Claims (18)

claims   1. A method of shaping and removing a cover (HO) packaging on a palletized load (CH), said cover being prepared from a flexible plastic sheath wound on at least one spool (11). 12), the method comprising: transversely welding the sheath (17) at its free end to create a heat-sealed connection (19) held in a low position by at least one positioner member (13, 14); storing on a transfer and accumulation device (15) a predetermined length of sheath to constitute said cover (HO), take up the lower free end, and lower the cover (HO) around the load (CH) to be wrapped in the now separated by its four corners, and characterized by the following intermediate steps of: - vertically drive the heat-sealed connection (19) to a high position by the positioner member (13, 14) movable height to an altitude locatedabove the upper face of the load (CH), - horizontally moving the transfer and accumulation device (15) in a single horizontal movement directed orthogonally with respect to the displacement of the positioner member (13, 14) for ensure the recovery of the lower end of the cover (HO).   Method for forming and removing a packaging cover (HO) on a palletised load (CH) according to claim 1, characterized in that during the return stroke of the transfer and accumulation device ( 15), the organ. positioner (13, 14) is moved to a waiting intermediate position just before said upper film-engaging position in the accumulator element (21).   14 2867452 3. A method of forming and removing a cover (HO) packaging on a palletized load (CH) according to claim 1, characterized in that a sheath of heat-shrinkable plastic material is used to make a cover ( HO).   4. A method of forming and removing a cover (HO) packaging on a palletized load (CH) according to claim 1, characterized in that a stretched plastic sheath is used to make the cover ( HO).   5. A method of forming and removing a cover (HO) packaging on a palletized load (CH) according to claim 3 or 4, characterized in that a double-V bellows sleeve wound to flat on at least one spool (11, 12).   6. A method of shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 3 or 4, characterized in that a tubular sheath without bellows wound flat on at least one coil (11, 12).   7. Apparatus for shaping and removing a cover (HO) packaging on a palletized load (CH), said cover being prepared from a flexible plastic sheath wound flat on at least one reel (11, 12), and comprising: - means for welding and cutting (16) of the sheath, - a device (15) for transfer and accumulation comprising an accumulator element (20) on which is wound a part of the sheath (17), and a spacing mechanism (21) of the open end of the sheath after transfer to the filling station (26), - at least one positioner member (13, 14) arranged between the coil (11, 12) and the accumulator element (20) for holding the sleeve (17), characterized in that the positioner member (13, 14) is movable in height in the preparation station (10). being coupled to an actuator (13a, 14a) so as to move the sheath (17) between a low position, and a high engagement position of the heat-sealed connection (19) in the storage cell (20).   8. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 7, characterized in that the device (15) for transfer and accumulation is mounted to pivoting on a vertical axis (29) of an actuating arm (31) to position the heat-sealed connection (19) parallel or perpendicular to the largest face of the load (CH).   9. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 7, characterized in that the positioner member (13, 14) is guided in vertical translation between a low position, an intermediate waiting position and a high position by a guide rod (13b, 14b) integral with a support (33).   10. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 9, characterized in that the support (33) is adjustable on a cross (35) horizontal secured to the frame (32), and is provided with two positioners (13, 14) that can be alternately facing the accumulator member (20) by a horizontal translational movement of the support (33).   11. Apparatus for shaping and removing a cover (HO) packaging on a palletized load (CH) according to claim 10, characterized in that the support (33) of the two positioners (13, 14) is mounted on a bridge (34) fixed to the frame (32) below the crossbar (35).   12. Apparatus for shaping and removing a packaging cover (HO) on a palletised load (CH) according to claim 10 or 11, characterized in that the positioning members (13, 14) hold sheaths ( 17) from two coils (11, 12) superimposed.   16 2867452 13. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 12, characterized in that the axis of the coils (11, 12) extends parallel to the handling carrier.   14. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 12, characterized in that the axis of the coils (11, 12) extends perpendicularly to the handling carrier.   15. Device for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 7, characterized in that the device (15) for transfer and accumulation is carried by a transfer trolley (30) associated with an actuating arm (31) to ensure the horizontal movement of the cover (HO) between the preparation station (10) and the filling station (26) before taking up by an arm deposition (37).   16. Apparatus for shaping and removing a cover (HO) packaging on a palletized load (CH) according to claim 15, characterized in that the removal arm (37) is provided with fingers (38) of conformation and pinching for the recovery at the four corners of the open part of a cover (HO) of heat-shrinkable plastic film.   17. Apparatus for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 15, characterized in that the removal arm (37) is provided with pleating fingers and for stretching (39) for successively accordion pleating of the plastic stretch film cover (HO) following the rotation of motorized rollers (40), followed by a transverse stretching at the four angles before the descent around the charge (CH).   18. Device for shaping and removing a cover (HO) packaging on a load (CH) palletized according to claim 11, characterized in that the two positioner members (13, 14) are associated with a pair of transfer and accumulation devices (15) with alternate movements to increase the packing rate of the machine.