Tool for gripping, orienting and releasing packages to be palletized, apparatus comprising said tool and palletization method

Abstract

A tool for gripping, orienting and releasing packages to be palletized, extending in a longitudinal lengthwise direction (X-X) and transverse widthwise direction (Y-Y) comprises: a support frame (10) on which there are mounted: a pair of jaws, arranged opposite each other in the transverse direction (Y-Y) and hinged so as to rotate about a respective horizontal pin, from a position for closing the tool into a position for opening the tool, and vice versa, upon operation of associated actuating means; each jaw comprising stop elements movable with respect thereto at the opposite longitudinal ends, each being configured to pass alternately from a position for closing / opening at least one end (PA) of the two opposite longitudinal ends of the tool and a position for opening / closing the longitudinal end of the tool (PP) opposite to the other end in the same longitudinal direction (X-X); an assembly (20) for rotating the tool about a vertical axis thereof (Z-Z).

Description

[0001] TOOL FOR GRIPPING, ORIENTING AND RELEASING PACKAGES TO BE PALLETIZED, APPARATUS COMPRISING SAID TOOL AND PALLETIZATION METHOD

[0002] DESCRIPTION

[0003] The present invention relates to a tool for gripping, orienting and releasing packages, an apparatus for moving packages, provided with said tool, and a method for palletizing packages.

[0004] It is known in the technical sector relating to the packaging of loose materials in packages, for example bags, boxes or bundles, filled and closed in corresponding plants, that there is the need, at the end of the packaging cycle, to stack closed packages on surfaces, such as pallets, for subsequent storage and / or transportation.

[0005] In the case of bags filled with products supplied in bulk to bagging machines, apparatus of the pick-and-place type are also known, these being designed to pick up the bags and arrange them on specially provided surfaces or pallets.

[0006] Said apparatus have a gantry-type structure inside which the package to be palletized is picked up from a supply line by a suitable gripping tool (also called “gripper” below) and deposited either directly on the pallet being formed or on a surface, formed by horizontally movable metal plates on which the layer is first formed, then squared off in the four lateral directions and then deposited on the pallet being formed by means of sliding opening of the metal-plate surface.

[0007] In the basic version, the packages are supplied into a gripping position by the gripping tool, which then moves along a longitudinal direction X-X and transverse direction Y-Y of a horizontal surface and rotates about its vertical axis Z-Z until the package is deposited in the desired position with the desired orientation. Once the package has been unloaded, the gripper returns into the pick-up position with a dead stroke where no packages are transported.

[0008] The known apparatus also includes apparatus which comprise a conveyor belt arranged aligned with the gripping tool along a longitudinal direction X-X of movement of the belt, with the tool deposited downstream of the belt itself; the gripping tool is able to perform a controlled movement in the longitudinal direction X-X and transverse direction Y-Y on a horizontal plane, until it reaches the programmed position for deposition of the package on the surface, and a rotation about its vertical axis Z-Z for correctly orienting the package with respect to the deposition arrangement of the packages to be obtained.

[0009] The conveyor belt is in turn movable on a carriage and pivotable about its vertical axis and mechanically connected to the gripping tool which it transports along with it during its movements in the X-X and Y-Y directions, This configuration ensures that the belt - and therefore the point for supplying and gripping the bags - always remains connected to the gripper, eliminating the need for the latter to perform displacements in order to pick up the package from a standby location where the package is waiting to be picked up. The conveyor belt travels at a high speed designed to “launch” the package inside the tool itself.

[0010] In order to obtain certain and repetitive positioning of the package with respect to the tool at the end of the launching step, one side of the tool is closed so as to form a stop surface for the incoming package.

[0011] Considering that at the point of entry and gripping inside the gripper the package is always oriented in the same direction - in the case of a bag, for example, with its selvedge always upstream in the feeding direction - it nevertheless happens that in the case of some layering configurations, determined by the stability requirements of the pallet, or in order to obtain a suitable orientation of the packages (for example so that specific graphic designs present on the packages are visible from the perimeter of the pallet) the package must be rotated through 180 degrees before being placed on the storage surface, essentially so as to ensure, for example, that the selvedges are arranged opposite each other on the support surface.

[0012] Since the tool has only one open side for entry of the package, this means that, once a first package with its orientation has been received and deposited, the gripper must rotate about its vertical axis in order to orient correctly a second package for correct positioning thereof on the surface and then perform again an idle rotation in order to reposition its inlet opening so that it is aligned with the conveyor belt and allow the launching of the next package inside it.

[0013] For the desired positioning of the packages on the storage surface, there is therefore an idle return rotation of the gripper which must reposition its open side in front of the conveyor belt in order to receive another package, said idle rotation inevitably increasing the cycle dead time and reducing the productivity of the plant.

[0014] The technical problem which is posed, therefore, is that of providing a tool for picking up, positioning and orienting packages to be deposited on a storage surface, such as a pallet, which tool is able to reduce the cycle dead time.

[0015] In connection with this problem it is also required that this tool should have small dimensions, be easy and inexpensive to produce and assemble and be able to be easily installed also in already existing packaging plants.

[0016] The present invention relates furthermore to an apparatus designed to move packages at a high speed for palletization thereof.

[0017] These results are obtained according to the present invention by a tool according to the characteristic features of Claim 1 , by an apparatus according to Claim 8 and by a method according to Claim 12.

[0018] According to the invention, the tool for gripping, orienting and releasing packages to be palletized, extending in a longitudinal lengthwise direction and transverse widthwise direction comprises: a support frame on which there are mounted: a pair of jaws, arranged opposite each other in the transverse direction and hinged so as to rotate about a respective horizontal pin, from a position for closing the tool into a position for opening the tool, and vice versa, upon operation of associated actuating means; each jaw comprising stop elements movable with respect thereto at the opposite longitudinal ends, each being configured to pass alternately from a position for closing / opening at least one end of the two opposite longitudinal ends of the tool and a position for opening / closing the longitudinal end of the tool opposite to the other end in the same longitudinal direction; an assembly for rotating the tool about a vertical axis thereof.

[0019] Said means for actuating rotation of the jaws comprise a cylinder fastened to a first transmission member rotating about the same pin of the first jaw and a piston of the cylinder pivotably mounted on a second transmission member rotationally connected to the second jaw.

[0020] The assembly for rotating the tool about a vertical axis thereof comprises a support integral with the frame and a gearwheel connected by means of a belt to an external drive. Each jaw has an L-shaped form with its short side directed inwards. The short sides are formed by a respective flat piece at the opposite ends of each of which there is hingeably mounted a stop element rotating about a respective hinge upon actuation of a respective cylinder joined together with the respective flat piece.

[0021] The apparatus for transporting, gripping, orienting and releasing packages to be palletized comprises a conveyor belt displaceable in the longitudinal direction on a frame pivoting about its vertical axis and a gantry structure which supports a carriage displaceable in both senses of the longitudinal and transverse direction by means of respective drives and transmissions, wherein the carriage supports a gripper according to the invention.

[0022] According to a preferred embodiment, the conveyor belt and the gripper are connected together so that the belt is driven by the gripper during its movements in the longitudinal and transverse directions, and the relative position of the gripper and the front end of the belt in the longitudinal direction remains fixed.

[0023] The method for gripping, orienting and releasing a package by means of an apparatus as described above comprises the following steps: arrangement of the gripper with the Front Part facing the conveyor belt; movement of the first stop elements of the Front Part into the open position and the second stop elements of the Rear Part into the closed position; introduction into the gripper of a first package transported by the belt; precise stopping of the package against the second stop elements in the closed position of the Rear Part of the gripper; displacement of the gripper into the correct position on the palletization surface; opening of the jaws of the gripper with unloading of the package and immediate closing again of the jaws in order to pick up a next package arriving from the belt; introduction of a next package into the gripper; rotation through 180 degrees of the gripper about its vertical axis with consequent corresponding rotation of the package through 180 degrees; displacement of the gripper into the correct position on the palletization surface; opening of the jaws of the gripper with unloading of the current package and immediate closing again of the jaws in order to pick up a next package arriving from the belt; closing of the stop elements of the Front Part and simultaneous opening of the stop elements of the Rear Part facing the belt; launching of the next package inside the gripper, resumption of the gripper positioning cycle so as to open the gripper and release the package with the correct orientation thereof according to the predefined palletization arrangement; starting of a new cycle for pick-up, positioning and release of a new package to be palletized.

[0024] According to preferred embodiments it is envisaged that:

[0025] - the opening / closing movement of the stop elements is a rotation;

[0026] - the package is a bag with its selvedge always oriented in the same direction on the conveyor belt;

[0027] - the bags are released onto the pallet with oppositely arranged selvedges.

[0028] Further details may be obtained from the following description of a nonlimiting example of embodiment of the subject of the present invention provided with reference to the attached drawings in which:

[0029] Figure 1 : shows a side view of a gripper according to the invention, in the closed condition, for gripping, orienting and depositing packages;

[0030] Figure 2: shows a perspective view of the gripper according to Fig. 1 in the open condition;

[0031] Figure 3: shows a perspective view of the gripper according to Fig. 1 in the closed condition with the device for rotation thereof;

[0032] Figure 4: shows a view, from below, of the gripper according to Fig.

[0033] 1 in the closed configuration;

[0034] Figure 5: shows a side view of the gripper according to the invention with opposite stop elements open on both sides;

[0035] Figure 6: shows a side view of the gripper according to the invention with opposite stop elements open on a first side and closed on the other side;

[0036] Figure 7: shows a side view of the gripper according to the invention with opposite stop elements open on a second side and closed on the first side;

[0037] Figure 8: shows a schematic perspective view of an apparatus for moving packages with a gripper according to the present invention;

[0038] Figs. 9A-9I: show a perspective view of the sequences for movement of the packages by means of the apparatus according to Fig.8; Figs. 10A-10B: show side views of the apparatus which illustrate the reduction in the empty space between the belt and gripper when the stop elements are in the open condition.

[0039] As shown in Fig. 1 and assuming solely for easier description and without a limiting meaning a set of reference axes respectively in a longitudinal direction X-X, corresponding to a lengthwise dimension of the gripper and, during use, the direction of movement of a feeder belt and entry of a package inside a gripper; transverse direction Y-Y, corresponding to a widthwise dimension of the gripper; and vertical direction Z-Z, orthogonal to the other two directions and corresponding to an axis of rotation of the tool; as well as a first Part, conventionally assumed to be a Front Part PA, and a second Rear Part PP, opposite to the preceding part, a tool according to the invention - below a gripper for gripping, orienting and depositing a package, in the example described generically by way of example as a bag S comprising a bottom F and a selvedge C - comprises essentially:

[0040] - a square frame 10 which supports:

[0041] - a pair of jaws 11 , preferably with an L-shaped form with the short side facing inwards, arranged opposite each other in the transverse direction Y-Y and rotationally movable about a respective horizontal pin from a closed position (Fig. 1) into an open position (Fig. 2); the rotation in the two senses for opening / closing respectively the jaws 11 Is provided by a cylinder 12 which is fastened to a first transmission member 13a rotating about a pin 15a of the first jaw 11 and by the piston 12a of the cylinder 12 pivotably mounted on a second pin 15b of a second transmission member 13b rotationally connected to the second jaw 11 ; preferably, and in order to obtain a rotation of the two jaws which is synchronized in both senses, means for synchronizing the opening / closing rotation of the jaws are provided; in the example shown said means comprise a connecting bar 14 which is arranged between the first transmission member and the second transmission member 13;

[0042] - an assembly 20 for rotating the gripper abut the vertical axis Z-Z (Fig. 3). comprising a support 21 integral with the frame 10 and a gearwheel 22 connected by means of a belt 22a to a drive (not shown).

[0043] According to the invention it is envisaged that the short sides of the L of the jaws are formed by a respective flat piece 11 b (Fig. 4) at the opposite ends of each of which there is movable a stop element 30 which, for the sake of greater clarity of the description, is indicated by 31 A if located on the front side PA of the gripper and 31 P if located on the rear side PP of the gripper. According to a preferred embodiment, the stop elements are rotatable about a respective hinge 32 upon operation of a respective cylinder 33, joined together with the respective flat piece 11 b and designed to move the stop elements from a rotated open position on both the opposite longitudinal sides of the gripper (Fig. 5) into a position where the gripper is closed on one side (Fig. 6) or on the other side (Fig. 7) of the opposite longitudinal sides of the gripper.

[0044] It is also possible, even though as will become clearer below the condition is not practical for the purposes, to arrange all the stop elements in the closed position on both sides of the gripper.

[0045] As illustrated schematically in Fig. 8, the gripper according to the invention is mounted on an apparatus 100 for transporting, picking up, orienting and releasing a bag; for the purposes of the present invention only the operationally fundamental parts of the apparatus will be described and illustrated, these comprising:

[0046] - a conveyor belt 110 displaceable in the longitudinal direction X-X on a frame 110a;

[0047] - the frame 110a is in turn pivotable in the direction Z-Z about its axis Z1 -Z1 located substantially at the opposite end of the said frame to the gripper in order to assist the movement of the said gripper in the direction Y-Y;

[0048] - a gantry structure 120 which supports a carriage 121 on which there is mounted the gripper according to the invention which is displaceable in both senses of the longitudinal direction X-X and transverse direction Y-Y by means of drives 123 and transmissions 123a conventional per se and only schematically shown in Fig.8; according to the prior art the conveyor belt and the gripper are connected together so that the belt is driven by the gripper during its movements in the directions X-X and Y-Y.

[0049] With this configuration, the relative position of the gripper and the front end of the belt in the longitudinal direction is fixed, eliminating the need for dead travel of the grippers in order to locate the position for gripping the bags.

[0050] With the gripper structure according to the invention, the sequences for gripping, orienting and releasing a bag comprise:

[0051] - arrangement of the gripper (Fig. 9A) with the Front Part PA facing the conveyor belt 110, first stop elements 31 A of the Front Part PA open and second stop elements 31 P of the Rear Part PP closed;

[0052] - arrival of a first bag S1 (Fig. 9B) carried by the belt 110 which, running at high speed, launches the bag S1 inside the gripper;

[0053] - during this step, the rear stop elements 31 P are closed and ensure the stoppage of the bag in the correct position, necessary for the following palletization operations;

[0054] - with the bag correctly oriented for positioning with its selvedge directed upstream, the gripper is brought into the correct position in the plane X-Y where it is opened (Fig. 9C), unloading the bag S1 , and immediately closed again in order to pick up a second bag S2 arriving from the belt 110;

[0055] - the bag S2 arrives with the selvedge C2 always on the rear side and must be rotated through 180 degrees in order to be arranged opposite the bag S1 already unloaded onto the pallet;

[0056] - during this step (Fig. 9D) the gripper is still in a favourable position with the Front Part PA facing the bag S2 so as to receive the launching thereof in a manner similar to that which occurred for the bag S1 ;

[0057] - once the bag has been gripped, the gripper is rotated about its vertical axis Z-Z (Fig. 9F) so as to bring the selvedge C2 opposite the selvedge C1 of the bag S1 and displaced into the correct position for release of the bag S2 onto the pallet (Fig. 9G);

[0058] - the gripper is opened (Fig. 9H) for release of the bag S2;

[0059] - at this point it is required to arrange the gripper in order to receive the bag S3 arriving from the conveyor belt;

[0060] - for this purpose (Fig. 9I) it will be sufficient to close the jaws 11 and the stop elements 31 A of the Front Part PA, rotating simultaneously into the open position the stop elements 31 P of the Rear Part PP which is now facing the belt 110, so as to allow the belt to launch the bag S3 inside the gripper and resume the gripper positioning cycle for opening thereof and release of the bag with the correct orientation thereof according to the predefined palletization arrangement.

[0061] It is therefore clear how the gripper according to the invention is able to be positioned with respect to the conveyor belt always with one side open for receiving the bag and one side closed for correctly stopping the incoming bag, without the need to perform rotations through 180 degrees when there is no bag, this being dead time which significantly reduces the palletization speed.

[0062] Advantageously, the open position of the stop elements also helps reduce the gap present between the ends of the belt and the gripper (Figs. 10A, 10B), favouring better guiding of the bag during launching inside the gripper and therefore a greater repeatability thereof. Considering that the step of gripping, orienting and releasing the bag for palletization according to the prior art is the slowest, the apparatus according to the invention, which avoids the dead time of an idle rotation, also allows the speed and therefore the productivity of the entire line to be increased.

[0063] Although described in connection with a number of embodiments and a number of preferred examples of implementation of the invention, it is understood that the scope of protection of the present patent is determined solely by the claims below.

Claims

CLAIMS1. Tool for gripping, orienting and releasing packages to be palletized, extending in a longitudinal lengthwise direction (X-X) and transverse widthwise direction (Y-Y), characterized in that it comprises:- a support frame (10) on which there are mounted:- a pair of jaws, arranged opposite each other in the transverse direction (Y- Y) and hinged so as to rotate about a respective horizontal pin, from a position for closing the tool into a position for opening the tool, and vice versa, upon operation of associated actuating means;- each jaw comprising stop elements movable with respect thereto at the opposite longitudinal ends, each being configured to pass alternately from a position for closing / opening at least one end (PA) of the two opposite longitudinal ends of the tool and a position for opening / closing the longitudinal end (PP) of the tool opposite to the other end in the same longitudinal direction (X-X);- an assembly (20) for rotating the tool about a vertical axis (Z-Z) thereof.

2. Tool according to Claim 1 , characterized in that said means for actuating the rotation of the jaws comprise a cylinder (12) fastened to a first transmission member (13a) rotating about the same pin (15a) of the first jaw (11 ) and a piston (12a) of the cylinder (12) pivotably mounted on a second transmission member (13b) rotationally connected to the second jaw (11).

3. Tool according to the preceding claims, characterized in that it comprises means for synchronizing the opening / closing rotation of the jaws.

4. Tool according to any one of Claims 1-3. characterized in that the assembly (20) for rotating the tool about a vertical axis (Z-Z) thereof comprises a support (21) integral with the frame (10) and a gearwheel (22) connected by means of a belt (22a) to an external drive.

5. Tool according to any one of Claims 1-4, characterized in that each jaw (11) has an L-shaped form with its short side directed inwards.

6. Tool according to the preceding claim, characterized in that the short sides of the “L” are formed by a respective flat piece (11b) at the opposite ends of each of which there is hingeably mounted a stop element (30) rotating about a respective hinge (32) upon actuation of a respective cylinder (33) joined together with the respective flat piece (11b).

7. Tool according to any one of Claims 1 -4, characterized in that itcomprises means for synchronizing the opposite rotations of the stop elements from the respective closed position into the open position, and vice versa.

8. Apparatus for transporting, gripping, orienting and releasing packages to be palletized, comprising:- a conveyor belt (110) displaceable in the longitudinal direction (X-X) on a frame (110a) pivoting about its vertical axis (Z1-Z1);- a gantry structure (120) which supports a carriage (121) displaceable in both senses of the longitudinal direction (X-X) and transverse direction (Y-Y) by means of respective drives (123) and transmissions (123a); characterized in that the carriage (121) supports a gripper according to Claims 1 to 7.

9. Apparatus according to any one of the preceding claims, characterized in that the axis of rotation (Z1-Z1) of the conveyor belt is located at the end of the frame itself, opposite to the gripper.

10. Apparatus according to either one of Claim 8 or 9, characterized in that the conveyor belt and the gripper are connected together so that the belt is driven by the gripper during its movements in the longitudinal direction (X-X) and transverse direction (Y-Y).

11. Apparatus according to any one of Claims 8-10, characterized in that the relative position of the gripper and the front end of the belt in the longitudinal direction is fixed.

12. Method for gripping, orienting and releasing a package by means of an apparatus according to Claims 8-11 , characterized in that it comprises the following steps: arrangement of the gripper with the Front Part (PA) facing the conveyor belt (110); movement of the first stop elements (31 ) of the Front Part (PA) into the open position and the second stop elements (31 P) of the Rear Part (PP) into the closed position; introduction into the gripper of a first package (S1) transported by the belt (110); precise stopping of the package against the second stop elements (31 P) in the closed position of the Rear Part (PP) of the gripper; displacement of the gripper into the correct position on the palletizationsurface; opening of the jaws of the gripper with unloading of the package (S1 ) and immediate closing again of the jaws in order to pick up a next package (S2) arriving from the belt (110); introduction of a next package (S2) into the gripper; rotation through 180 degrees of the gripper about its vertical axis (Z-Z) with consequent corresponding rotation of the package through 180 degrees; displacement of the gripper into the correct position on the palletization surface; opening of the jaws of the gripper with unloading of the current package (S2) and immediate closing again of the jaws in order to pick up a next package (S3) arriving from the belt (110); closing of the stop elements (31 A) of the Front Part (PA) and simultaneous opening of the stop elements (31 P) of the Rear Part (PP) facing the belt (110); launching of the next package (S3) inside the gripper, resumption of the gripper positioning cycle so as to open the gripper and release the package with the correct orientation thereof according to a predefined palletization arrangement; starting of a new cycle for pick-up, positioning and release of a new package to be palletized.13 Method according to the preceding claim, characterized in that the opening / closing movement of the stop elements is a rotation.

14. Method according to Claims 12 and 13, characterized in that the package is a bag (S1 ;S2;S3) with its selvedge (C1 ;C2;C3) always oriented in the same direction on the conveyor belt.

15. Method according to one of the preceding claims, characterized in that the bags are released onto the pallet with oppositely arranged selvedges.

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