Technical Field

The present invention relates to an upgraded prehensile device for robotized systems, usable in particular for palletizing products or packs of products.

Background Art

In the field of industrial automation, the use has been known for some time of robotized systems able to make the manufacture, handling and storage of products or the like faster and more precise.

With special reference to the palletizing of products or packs of products, the use is known of robotized systems such as anthropomorphic robots, having suitable prehensile devices, suitably made for picking up and handling one or more products or packs of different sizes.

Conventionally, such anthropomorphic robots are used in a palletizing station located e.g. at the outfeed of a product boxing line.

Inside the palletizing station one or more empty-pallet feeding stations and one or more palletizing stations are, in general, arranged.

Using a prehensile device, the robot picks up an empty pallet from the relative station and arranges it inside the station dedicated to palletizing.

Subsequently, the robot picks up the single products or packs of products and arranges them along one or more rows on the pallet.

The pallets so arranged can be subsequently moved away in an automated way or picked up by an operator using a fork-lift truck or the like.

One type of prehensile device, usable in particular for palletizing products or packs of products, commonly comprises:

- a supporting structure;

- fastening means fixed integral with the supporting structure and which can be connected to a robotized system of the type of an anthropomorphic robot;

- one or more pickup grippers associated with said supporting structure and arranged aligned the one with the other. Each of the grippers has a pair of jaws, moving between an opening configuration, wherein these are aligned with one another, and a closing configuration, wherein they are substantially close to one another.

The grippers, furthermore, can be translated on the supporting structure moving closer to/away from one another, so as to allow picking up a large-size pack or the simultaneous picking up of several packs.

The prehensile devices of known type, furthermore, can have a pair of supplementary jaws which can be used to grip empty pallets, hinged to the supporting structure and which can be turned between a raised position and a lowered position.

These prehensile devices of known type, nevertheless, do have a number of drawbacks.

The opening and closing of the grippers and the approach/away movement of the grippers, as well as the rotation of the supplementary jaws, are movements at least one of which is controlled pneumatically or hydraulically .

This involves a number of drawbacks:

- movements that are not always precise and not always reliable grip control;

- movements which are sometimes too sudden that can damage the products or the product packs to be handled;

- limited handling operation speed;

- difficulty in reaching intermediate gripper positions (or of the supplementary jaws);

- a certain structural complexity of the prehensile device which, furthermore, gives it a not very nice appearance and calls for complicated maintenance jobs which are very time consuming.

Description of the Invention

The main aim of the present invention is to provide an upgraded prehensile device for robotized systems, in particular for palletizing products or packs of products, which allows more precise movements for a better grip control.

Another object of the present invention is to provide a prehensile device for robotized systems which permits more gradual movements, such as to restrict to the utmost the risks of damaging the products or product packs to be handled. Another object of the present invention is to provide a prehensile device for robotized systems which permits faster handling operations.

Another object of the present invention is to provide a prehensile device for robotized systems which permits a higher speed of the movement operations. Another object of the present invention is to provide a prehensile device for robotized systems which permits a precise positioning of the grippers in any intermediate position.

Another object of the present invention is to provide a prehensile device for robotized systems which is simpler and has a nicer appearance.

The above objects are achieved by the present upgraded prehensile device for robotized systems, in particular for palletizing products or packs of products, comprising:

a supporting structure;

- fastening means associated integral with said supporting structure and associable with a robotised system;

at least two grippers associated with said supporting structure;

wherein each of said grippers has at least a pair of jaws, moving between an opening configuration, wherein they are moved away from one another, and a closing configuration, wherein they are substantially close to one another;

wherein at least one of said grippers is moving on said supporting structure along a direction of moving closer and/or moving away from the other of said grippers;

- at least a pair of supplementary jaws associated with said supporting structure and rotating between a raised position and a lowered position; characterised by the fact that it comprises motor means of the electric type for moving said grippers between the opening configuration and the closing configuration, for moving at least one of said grippers along the direction of moving closer and/or moving away and for moving said supplementary jaws between the raised position and the lowered position.

Brief Description of the Drawings Other characteristics and advantages of the present invention will become more evident from the description of a preferred, but not sole, embodiment of an upgraded prehensile device for robotized systems, usable in particular for palletizing products or packs of products, illustrated purely as an example but not limited to the annexed drawings in which:

figure 1 is a plan view of an embodiment of a palletising station in which the prehensile device according to the invention is usable;

figure 2 is an axonometric view of the prehensile device according to the invention fitted on a robotized anthropomorphic arm;

figure 3 is a front view of the prehensile device according to the invention;

figure 4 is a side view of the prehensile device according to the invention;

figure 5 is a rear view of the prehensile device according to the invention, with the two grippers moved away from each other and the supplementary jaws in the raised position;

figure 6 is a rear view of the prehensile device according to the invention, with the two grippers moved close to each other and the supplementary jaws in the lowered position;

figure 7 is a plan view from above of the prehensile device according to the invention;

figure 8 is a section view of the prehensile device according to the invention along the VIII- VIII section plane of figure 7;

figure 9 is a section view of the prehensile device according to the invention along the IX-IX section plane of figure 7;

figure 10 is a section view of the prehensile device according to the invention along the X-X section plane of figure 7.

Embodiments of the Invention

With particular reference to such figures, globally indicated by 1 is an upgraded prehensile device which can be fitted on robotized systems and usable, in particular, for palletizing products or packs of products.

Preferably, as shown in the figures 1 and 2, the device 1 can be installed on a robotized system of the type of a robotized anthropomorphic arm and can be used to palletize packs P of products packed in boxes or the like. The installation of the device 1 on different robotised systems and its being used for other purposes cannot however be ruled out.

By way of example, the figure 1 shows a possible palletizing station for packs of products packed in boxes.

The device 1 is fitted on a robotized arm A, of the type of an anthropomorphic robot with four freedom axes.

Inside the palletising station are arranged:

- a motorised roller conveyor B, exiting from a boxing line and suitable for moving the packs P of products to be palletized;

- a first station C for supplying the empty pallets;

- a second station D for supplying interleaves;

- a third and a fourth palletizing station E and F.

The robotized arm A, by means of the device 1, picks up an empty pallet from the relative first station C and positions it inside the third or fourth palletising stations E or F.

Subsequently, the robotised arm A picks up an interleaf from the relative second station D and positions it on the pallet.

Afterwards, the robotised arm A picks up the packs P of products moved by the conveyor B and arranges them alongside one another on the pallet.

Once a layer of packs P has been completed, the robotized arm A picks up another interleaf and positions it on the packs P.

Once one or two pallets positioned in the third and fourth stations E and F have been loaded, they are conveyed away in an automated way by means of special conveyors or are picked up by an operator using a fork-lift truck or the like. Figure 2 schematically shows the robotised arm A, on which is fitted the device 1, during the picking up of a pair of packs P from the conveyor B.

The device 1 comprises a supporting structure 2 which, in the particular embodiment shown in the illustrations, consists of a metal frame with a substantially overturned T shape.

Different shapes of the supporting structure 2 cannot however be ruled out.

The device 1 also has fastening means 3 of the conventional type, made in correspondence to the upper portion of the supporting structure 2 and suitable for fastening and connecting, electrically and electronically, the device 1 to the free extremity of the robotized arm A.

Preferably, the fastening means 3 are composed of quick coupling and release means.

Usefully, the device 1 comprises two grippers 4 which are associated in correspondence to the lower portion of the supporting structure 2, aligned with one another and usable for picking up a large-size pack P or for the simultaneous pickup of two, three, four or more packs P of smaller dimensions. It is pointed out that, in this description, by "upper" or "lower" reference is made to the common arrangement of the device 1 when this is used to pick up packs P from above, with the grippers 4 suitable for tightening on the two opposite walls of the packs themselves.

Each of the grippers 4 has a pair of jaws 5, composed of vertical blades, which are moving along a first and a second axis Al and A2 respectively between:

- an opening configuration wherein the jaws 5 are moved away from each other and are in a first end-of-stroke position corresponding to the greatest possible distance between them, and

- a closing configuration, wherein the jaws 5 are moved close to one another and are in a second end-of-stroke position corresponding to the smallest possible distance between them.

Both configurations are shown in the figure 4, the closing configuration being shown by the broken line.

Furthermore, both the grippers 4 are moving on the supporting structure 2 along a direction of moving closer and/or moving away, shown in the illustrations with the third axis A3.

In point of fact, the relative position between the two grippers 4 can be changed by translating the grippers themselves along the direction of moving closer and/or moving away A3, so as to allow picking up packs P of different dimensions or also the simultaneous pickup of two, three, four or more packs. The maximum and minimum distance positions between the two grippers 4 are shown in the figures 5 and 6 respectively.

Usefully, the device 1 comprises a pair of supplementary jaws 6, associated with the supporting structure 2, rotating between a raised position and a lowered position and usable to grip the empty pallets.

Each of the supplementary jaws 6 is composed, in particular, of a small frame which has an extremity hinged to the supporting structure 2, in correspondence to a fourth hinging axis A4, and an opposite extremity having a hook 7 suitable for inserting itself below the pallets to be handled.

Usefully, the supplementary jaws 6 are provided, in correspondence to the free extremities, with respective pairs of suction cups 8, connected to a suitable extraction circuit 9 and usable to pick up the interleaves to be positioned between one layer of packs P and the next.

Advantageously, the device 1 according to the invention comprises motor means of the electric type which are suitable for:

- translating the jaws 5 of the grippers 4 along the first and the second axis Al and A2, between the above opening and closing configurations;

- translating the grippers 4 along the above direction of moving closer and/or moving away A3;

- rotating the supplementary jaws 6 around the fourth axes A4, between the above raised and lowered positions.

Preferably, such motor means of the electric type are made up of one or more electric servomotors or the like.

The use of electric motors and of electric servomotors, with respect to handling systems of known type, allows obtaining the following advantages:

- more precise movements for greater grip control;

- more gentle movements which allow reducing to the utmost the chance of damaging the packs P to be handled;

- higher handling operation speed;

- the chance of precisely positioning the grippers 4 and the supplementary jaws 6 in any intermediate position;

- a more simple device 1 which makes maintenance jobs more simple and faster and which, at the same time, gives the device 1 a more pleasant and cleaner look.

Advantageously, the motor means comprise a pair of first electric motors 10 which are suitable for moving each of the grippers 4, respectively, between the opening configuration and the closing configuration.

In particular, the device 1 comprises first transformation means 1 1 , suitable for transforming the rotary movement produced by the first electric motors 10 into the translational movement of the jaws 5 of each of the grippers 4.

Preferably, for each of the grippers 4, the first transformation means 1 1 comprise transmission means of the screw-nut screw type which use, e.g., a system with re-circulating ball screw.

Different embodiments of the first transformation means 1 1 cannot however be ruled out.

In particular, each of the grippers 4 comprises a carrying element 12 with a substantially elongated shape, associated with the supporting structure 2, moving along the direction of moving closer and/or moving away A3 and arranged with the longitudinal axis substantially at right angles with respect to such direction A3.

Each of the grippers 4 also comprises a pair of slides 13 for supporting the jaws 5, supported sliding by first rectilinear guide means 14, of the type of a suitably profiled bar or the like, which extend longitudinally along the lower portion of the carrying element 12, along the first axis Al or the second axis A2.

For each of the grippers 4, the first electric motor 10 is fastened to an extremity of the carrying element 12 and the first transformation means 1 1 comprise:

- a first driving shaft 15, housed axially rotating inside the carrying element 12 and having a first portion 15a and a second portion 15b substantially opposite one another, both threaded and with opposite threading direction the one with respect to the other;

- a first pulley 16 associated integral with the shaft of the first electric motor 10, a second pulley 17 associated integral with an extremity of the first driving shaft 15 and a first belt 18 for connecting the first and the second pulley 16 and 17;

- a pair of first nut screws 19, engaged on the first portion 15a and on the second portion 15b of the first driving shaft 15 respectively and associated integral with the respective slides 13. Advantageously, the first electric motor 10 thus controls the rotation of the first driving shaft 15, moving horizontally the first nut screws 19 relatively close to or away from one another (along the first axis Al or the second axis A2) and thereby regulating the position of the two jaws 5.

Preferably, the first electric motor 10 is composed of an electric servomotor. The use of the first electric motor 10, together with the first driving shaft 15 and with the pair of first nut screws 19, allows the fine adjustment of the position of the two jaws 5 and the gentler movements of the jaws themselves.

The motor means also comprise a second electric motor 20 which is suitable for moving the grippers 4 along the direction of moving closer and/or moving away A3.

In particular, the device 1 comprises second transformation means, indicated altogether by the reference 21, which are suitable for transforming the rotary movement produced by the second electric motor into the translational movement of both the grippers 4 along the direction A3.

Preferably, the second transformation means 21 comprise driving means of the screw-nut screw type which use, e.g., a system with re-circulating ball screw. Different embodiments of the second transformation means 21 cannot however be ruled out.

The device 1 comprises a pair of trolleys 22 for supporting the grippers 4, supported sliding along the direction of moving closer and/or moving away A3 on second rectilinear guide means 23, of the type of a suitably profiled bar or the like, which extend longitudinally along the lower portion of the supporting structure 2.

The second electric motor 20 is fastened to a protruding lateral portion of the supporting structure 2 and the second transformation means 21 comprise:

- a second driving shaft 24, associated axially rotating along the lower portion of the supporting structure 2 and having a first portion 24a and a second portion 24b substantially opposite one another, both threaded and with opposite threading direction the one with respect to the other;

- a third pulley 25 associated integral with the shaft of the second electric motor 20, a fourth pulley 26 associated integral with an extremity of the second driving shaft 24 and a second belt 27 for connecting the third and the fourth pulley 25 and 26;

- a pair of second nut screws 28, engaged on the first portion 24a and on the second portion 24b of the second driving shaft 24 respectively and associated integral with the respective trolleys 22.

Usefully, the second electric motor 20 thus controls the rotation of the second driving shaft 24, moving the second nut screws 28 horizontally relatively close to or away from one another (along the third axis A3) and therefore regulating the position of the two grippers 4.

Preferably, the second electric motor 20 is made up of an electric servomotor. Advantageously, the use of the second electric motor 20, together with the second driving shaft 24 and the pair of second nut screws 28, allows the fine adjustment of the position of the two grippers 4 and the gentler movements of the grippers themselves.

The motor means of the device 1 furthermore comprise a third electric motor 29 which is suitable for moving the supplementary jaws 6 between the raised position and the lowered position.

The device 1 comprises third transformation means of the movement, indicated altogether by the reference 30, suitable for transforming the rotary movement produced by the third electric motor 29 into the rotary movement of the supplementary jaws 6.

Preferably, the third transformation means 30 comprise belt drive means or the like. Different embodiments cannot however be ruled out.

The third transformation means 30 comprise:

- a drive pulley 31, which is associated integral with the shaft of the third electric motor 29;

- a first and a second driven pulley 32 and 33, arranged below the drive pulley;

- a third driven pulley 34, associated integral with one of the two supplementary jaws 6 in correspondence to the fourth hinging axis A4;

- a fourth driven pulley 35, associated integral with a first gear wheel 36;

- a third driving belt 37 connecting the drive pulley 31 and the driven pulleys 32, 33, 34 and 35;

- a second gear wheel 38, associated integral with the other supplementary jaw 6, in correspondence to the fourth hinging axis A4, and engaged with the first gear wheel 36.

Usefully, the third electric motor 29 thus controls the rotation of the third driven pulley 34 and of the second gear wheel 38, rotating the supplementary jaws 6 between the raised position and the lowered position.

Preferably, the third electric motor 29 is made up of an electric servomotor. Advantageously, the use of the third electric motor 29, together with the belt driving means, allows the fine adjustment of the position of the two supplementary jaws 6 and gentler movements of the supplementary jaws themselves.

The device 1 also has a pair of pads 39, of the conventional type, which can be translated horizontally along the supporting structure 2 and moving vertically, usable to favour the detachment of the packs P from the device itself after the opening of the grippers 4.

It has in fact been ascertained how the described invention achieves the proposed objects.