The present Patent for Industrial Invention relates to an automatic unloading system at the outlet of machines for producing paper bags or paper and plastic film bags.

The present automatic unloading system is the missing element in the production lines of paper bags or also paper bags with a transparent strip; such a system performs the automatic unloading in "packages" of desired dimensions or number of bags, generally from 50 to 100 pieces each, automatically, i.e. without the presence of an operator. Indeed, currently one or also two operators are to be present in line on the bag making machine to remove the packages of bags produced and then bind them manually or with manual strapping tools or with simple elastic rings of the traditional type.

Indeed, starting from the simple general paper tape or with a strip of transparent plastic film, during the path that starts from the roll of paper to the formed bag, bag making machines perform a series of processing operations of pre-perforation, forming the tubular body, and both longitudinal and transverse gluing, up to the complete production of the finished paper bag, then at the end of the processing path, the finished bag is stacked according to a horizontal axis on an unloading plane in almost radial direction with respect to the forming drum of the machine. Proceeding in the unloading of the bags one after the other against a contrast abutment parallel to the plane of the bag, a continuous stack of bags arranged orthogonally to the support plane is formed with the opening of the bags upwards; to allow the successive taking at the outlet by an operator, at the wanted number of bags, for example, every fifty bags, the fifty-first, by means of a suitable preset counter, is released by the pliers of the drum slightly in advance and is unloaded into the stacker, protruding from the stack itself like a bookmark, the reason for which a characteristic horizontal stack is formed with said "bookmarks" clearly visible to the operators appointed to unloading, who remove them in packages equal to the distance between one bookmark and the next, and equal, like in the example mentioned, to the number of fifty bags each.

Since said machines are very fast, also up to productions equal to 800 bags per minute, it is understood how often a single operator is not capable of dealing with said productions by completing the binding or in any case a packaging, as required.

Another element of difficulty in packing the final production of these bags is the presence in many current productions of long and narrow bags, such as for example the ones intended for packaging bread such as traditional baguettes, which are difficult to keep stacked also for very short stacking paths.

The present system resolves both the noted problem of high production speeds and of the dimensions of said long bags with a single solution by operating both quickly and while not undergoing any conditioning due to the length.

In the current art, there is no machine or equipment on the market intended to grip packages outcoming from the production line of a bag making machine. The present automatic unloading system is combined with a traditional bag making machine and in particular, in the final area, immediately after the outlet drum of the bags, where normally a plate with wheels with abutment pins is arranged, where the bags just formed are collected. Applied on said outlet plate is a spreader equipped with two oscillating movements, a primary one for positioning the whole system and a secondary one for opening two shaped plates such as to separate the end of one package just produced from the beginning of the following one, all during the continuous production of the bags outcoming from the drum. The whole set carrying the spreader is also provided with a vertical movement for allowing the cycle start repositionings. During the opening of the spreader, pliers with shaped teeth are inserted into the spreader between two separate packages of bags, i.e. the flat teeth of the pliers find room between similar alternate teeth of the spreader so as to seize, from below, the stacked bags with glued bottom downwards. Once a pre-counted package of bags is seized, the pliers begin spacing themselves apart from the new package being formed by moving towards the outlet of the machine with the pliers upwards, i.e. in the same direction towards which they were detached. As soon as the pliers have travelled a few centimeters, they rotate by ninety degrees, thus causing the last bag of the package to rest on a sliding plane or slide and then said pliers pull the package towards the end of the machine, thus allowing to keep it taught and supported on an almost continuous plane, whatever the length of the model of the bag produced. From here, a transverse cylinder sends the package towards an automatic binding device. Due to reasons of practicality in the successive handling operations, said packages are made with a number of bags varying from 50 to 100 pieces, generally the bags are made of paper or of paper and transparent film so the contents may be viewed. During the movement towards the unloading of the pliers with their package of bags, the spreader, passing below the package being produced, is repositioned towards the drum where the bags produced continuously are formed and are outlet, waiting for the set quantity to be made and also for the pliers, which are arranged on a linear actuator, they also oscillating downwards, to return below the package being produced in open position to seize the new package formed at the proper count.

The device herein referred to as a spreader is fundamental to the present unloading system, which spreader divides two adjacent packages with certainty, the spreader being provided with two oscillations which are fundamental to the whole assembly, a primary one where the whole spreader is arranged towards the drum behind the first bag of the package being produced, and a secondary one where at the end of the package, moved forwards, it opens on itself like scissors to allow the gripping of the pliers.

As already mentioned, these machines have high productions which reach 800 pieces produced per minute, with variable dimensions of the different types of bags which, in a common machine, vary for example, from dimensions of 8cm x 18cm up to 30cm x 75cm. This apparatus formed by spreader and pliers may operate indifferently on all the sizes.

The different indexes, generally numerical, in the accompanying drawings have been attributed with the meanings hereinafter indicated for easier reading of said drawings.

100 Assembly of the outlet set and automatic unloading system of a machine called a bag making machine, said set is formed by the outlet drum of the finished bags, its load-bearing structure formed by a pair of lateral sheets, the unloading set, with wheeled plate and outlet plate, with following a spreader system 300, a gripping system 200 with sliding pliers for recovering and transporting the bags and the possible overturning of the package of bags at the unloading stop.

200 Assembly of the complete gripping system, provided with trolley sliding linearly with pliers, rotating by 90°, for gripping bags produced in preset number and horizontally transported, after said rotation of 90 degrees, up to unloading onto an unloading plane with possible movement and lateral binding.

300 Assembly of the mechanical set forming the spreader, i.e. the mechanism selected for separating the packages of bags, which one-by-one are picked by the pliers to be moved away from the unloading system, packages with a predetermined number of bags, the present spreader depicts the operating fulcrum of the present automatic unloading system because it decides on the order and operating frequency between the production drum and the packages of bags outcoming from the machine.

210 Mechanical pliers provided with two flat gripping teeth, a fixed one and a movable one by means of a pneumatic actuator, mounted with a hinge on the sliding trolley and provided also with rotation, always by means of a second pneumatic cylinder.

211 Pneumatic cylinder with sliding axis parallel to the closing direction of the pliers themselves.

215 Linear sliding trolley anchored to the movable slide of actuator 221.

215/A, 215/B and 215/C Three positions of the pliers holder trolley are indicated during the movement thereby from the gripping area A, in motion B, and rotated at stop for unloading in C.

216 Cylinder for the rotation of the pliers in order to spread the package taken over the sliding plane.

220 Transport assembly, actuator with trolley.

221 Electric linear actuator, system with speed, acceleration and stop that can be adjusted by the user.

222 Pneumatic actuator, raises and lowers actuator 221 with complete trolley and pliers.

230 Sliding plane of the package of bags transported to the unloading system by the pliers 210.

232 U-shaped tracks on plane 230 to facilitate the lateral right-hand or left-hand unloading of the package of bags towards a possible external binding device such as e.g. a strapping tool.

305 Vertical cylinders or actuators for completely lifting and lowering the spreader set 300.

310 Shaped plates or in any case opening planes of the spreader or in any case spacers of two adjacent packages of bags outcoming from the plate of the forming drum.

312 Cylinders or actuators for the oscillation of the spreader plates 310, oscillation with respect to the axis of the hinges 316 arranged at the lower end of 310.

315 Cylinders or actuators for opening/closing the two shaped plates 310 in the manner of scissors.

316 Oscillating and opening hinge of the spreader, i.e. of the plates 310.

325 Cylinder or actuator for positioning the whole spreader set for the start and end loading cycle of the bags in the package of desired measurement.

326 Hinge with spreader supports, thereon oscillating the whole set 300, moved by cylinder 325, which positions, as mentioned, the set at packing cycle start.

400 Indication of the general package of bags completed.

410 Package of bags during the formation of 400 not yet completed.

500 Machine or set for producing bags, in particular the outlet drum of the finished bags, said bag making machine with guides and supports of the bags.

510 Outlet drum.

511 General puller of the bags produced.

520 Structure of machine 500.

550 Outlet and unloading set with wheels, plate, belts and guides for vertically stacking the bags.

600 Mechanical feeler that contains the package of bags towards the outlet rack.

650 Lateral extraction cylinder of the package of bags towards the strapping or binding device.

Passing now to a first examination summary of the accompanying drawings, and in particular to the meaning of the different figures therein which depict the following.

• Fig. 1 - From a comprehensive view of machine 500 which produces bags of various measures, with drum 510 and the unloading system 550 to which spreader 300 was applied, which separates package 400 of bags outcoming from that under production 410 and allows the pliers 210 to accompany it with the transport to the unloading system and to a possible packing.
• Fig. 2 - View of device 300 as a whole.
• Fig. 3 - Views, in the orthogonal projections, again of 300 with the detail of the various functional components operating the operating movements of the spreader.
• Fig. 4 - Side view of the transport system of the package of bags 400 pulled by the pliers 210 applied on the trolley of actuator 211 and perspective view of 220.
• Fig. 5 and Fig. 6 - Describe the operating steps in sequence of the automatic unloading system of the package of bags 400 operated by spreader 300 and pliers 200.

Starting again in detail with Fig. 1, from this first assembly, the operating principle and concept of the subject of the present Patent may be traced back to, which, arranged in line with machine 500 that produces the bags (herein depicted only in the final area, i.e. at the end of the production of the bags themselves) on the unloading drum 510 where there are arranged the pliers of the drum itself which squeeze, transversely to the tubular body, the glued and closed bottom of the bag, up to the collection guides and table. As already mentioned, said machines may work with productions which reach even 800 bags per minute, unloading them continuously with a bag serving as a bookmark protruding at the end of each package, a package formed usually by a number varying between 50 and 100 pieces.

The present automatic unloading system replaces the operators who manually take the packages while binding them in different manners to tie them with elastics or strapping or automatic binding while always manually supporting the bundle.

As mentioned, said automatic unloading system consists of two sets which are complementary to each other, i.e. the first, spreader 300 dimensionally prepares the package of bags produced outcoming from the machine, generally it separates from 50 to 100 pieces thereof, holds them vertically, even if they have an increased length like the bags intended for fresh French bread, or baguette, also up to 70-75 cm, then once the number of pieces is reached, it "detaches" the completed package from the one being formed and therefore allows the gripping of the first by the pliers set 200 provided with the transport movement, thus causing the package to slide on a specific table 230 up to a final area where an actuator or a general transverse pusher moves it towards a binding system, as used in these processing operations.

The successive table no. 2 in Fig. 2 notes the assembly mounted in perspective view with all the actuators applied in 300 itself to provide a complete comprehensive depiction of the present set 300, while the successive Fig. 3 shows the three fundamental graphic views, where there are noted all the actuators selected for the movements, for example of 310, opening/closing with 315, oscillating on 316 by means of 312 of 310, oscillating the whole set by means of 325 and finally, raining/lowering always the whole set by means of 305.

The shape of 310, spreader plates or planes, which are hollowed out in the lower area, towards 316, may also be noted, in order to allow the passage of the gripping teeth of the pliers 210 when they grip the bottom of the complete package 400 of the bags outlet from the forming machine.

The successive Fig. 4 is dedicated to the gripping pliers 210 with the different devices and actuators which characterize it both in the gripping, 211, and in the transport 221, indeed, starting from the right, where the spreader can be recognized, the pliers 210 may be recognized facing upwards, 215/A, in the specific function of gripping and seizing of 400 just formed. Then it moves towards plane 230 in position 215/B, taking gripped with it package 400 to rotate it, spreading it out, over plane 230 itself and pulling it up to releasing it in position 215/C of the trolley itself. It is worth noting that by pulling and dragging package 400 to rotate it, the present transport system allows also working on very long packages of bags which, as disclosed below, are carried vertically by a containment feeler, therefore by releasing them therefrom, they rest on plane 230 to be easily unloaded onto a side of the plane for either a manual but also automatic binding into bundles, as used and required in this field.

All the present description relates to the technical and mechanical structure of the two groups 300 and 200, components and movements related to the pliers and the spreader selected for the automatic unloading system; indeed to better clarify the continuous operation, hereinafter and in Figures 5 and 6, the sequence of the operations is indicated while noting the positions taken both by the spreader with its components and the pliers with their trolley.

All steps have been indicated with the aid of Roman numerals from I to XVIII.

Step I shows spreader 300 towards the drum waiting for the load of bags outcoming from the bag making machine, II shows the pliers 210 open at the bottom and the plates 310 closed in top position, then in III the formation of package 400 and the plates 310 stopped up high up to the completion of 400.

In IV, the plates are rotated by the cylinders 312 and rotate to contain the end of the formation of 400 and allow the start of a new package 410 continuously but separately from the preceding one, like in V, then the cylinders 315 spread the plates 310 as much as required to separate the bottom of the bags, position VI. Then in VII and VIII, while more bags continue reaching the rack of the drum, cylinder 222 is raised with the pliers 210 while 325 executes the primary rotation of spreader 300.

In step IX, there is the seizing by the gripping pliers of package 400 with feeler 600 which ensures the support towards the outlet of 400 itself, therefore in X, 210 retracts and with the aid of 600, the bags are sent to rotate to the right, towards the drum, as shown in X. Then in XI, the gripped pliers 210 rotate by 90° towards the drum, actuator 216, while supporting package 400 on plane 230, and then 310 they are closed by means of the cylinders 315 and are lowered through the movement of the cylinders 305.

From position V, a new bundle 410 is being formed which increments up to the end of step XII, indeed at positions XII and XIII, while the pliers move away with 400, the lowered spreader rotates by means of 325 towards the drum and is raised again, repositioning itself behind the new package 410 in formation to begin a new cycle of separating the packages, while in XIV the pliers 210 continue their operation, releasing their gripping of package 400 which in XV is unloaded transversely by a pusher 650 to be bound or strapped here or also simply packaged outside the line for forming the various packages 400.

At this point, 210 rotates by means of cylinder 216 (position XVI) and travelling plane 230 (in XVII), is repositioned in the "low" gripping position (in XVIII) with cylinder 222 and the electromechanical actuator 221, which are arranged like in position II, waiting for the unloading of the bags from the bag making machine to be completed to form a package 400 and therefore resume the taking and transport cycle of this package 400.

As said many times, these packages of bags have highly variable parameters, from the width to the length of the bag and the number in which they are packaged from 50 to 100. Therefore, this packaging system apparently resolves the problem of the long and narrow bags contained here, at the time of unloading they are pulled by feeler 600 in the high and open area of the bag and by the pliers 210 from below, by individual package 400, towards the unloading system, while folding themselves naturally during the rotation and pulling as is clearly noted in positions X and XI of Fig. 5, moreover, said rotation of 210 occurs at 250 mm from the start of the pulling of the bags which are supported on plane 230.

It is apparent that what is depicted and described herein notes only one possible practical, preferable but non-limiting embodiment of the present invention, which may be different for arrangements of equipment and actuators, however without departing from the conceptual scope underlying the invention.

Any reference numerals in the claims serve the sole and unique purpose of facilitating the reading in light of the description and depictions in the accompanying drawings.