Technical field
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The present invention relates to an automatic wrapping machine and, more specifically, to an automatic wrapping machine comprising a cord tying system in accordance with the claims accompanying this descriptive report.
State of the art
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An automatic arm wrapper is a type of machine used to wrap products in plastic film or stretch film. Compared to manual wrapping, an automatic arm wrapper can wrap products quickly and uniformly, reducing the time and effort required to package loads for temporary movement or storage. Furthermore, automatic arm wrappers can provide more uniform and consistent wrapping, helping to ensure secure coverage of products. This reduces the risk of damage to the product during transport or storage and can help maintain the quality of the packaged product.
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For example, the prior art includes document
ES2055965 , which describes a system for sealing the tail end of a plastic sheet using high heat for sealing purposes. Document
US5802810 describes a system for securing the end of a roll of film once it has been placed around the load. The system is characterised by two arms actuated by pneumatic pistons that move away from and towards the load during the wrapping process. Documents
US20220002012A1 ,
ES2650408 ,
ES2191363T3 ,
US4418510A ,
US4432185A ,
US4619102A ,
US4845920A and
US4235062A also belong to the prior art.
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Part of the wrapping process with an automatic wrapper is the treatment of the end of the string or excess film that may remain at the end of the load wrapping. This excess must be adjusted in some way to the load to prevent the wrapping from coming undone during transit and the product from being compromised. There are many ways to handle this excess plastic, but compared to the prior art, the present invention describes a fast, effective and easy-to-install system that allows for continuous production without the need for heat or adhesives, in accordance with the attached claims.
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Document
US5802810A describes a method and apparatus for wrapping and securing a film around a load by placing a first arm that retains an end portion of the film towards the load, wrapping a layer of film around the first arm so that the first arm is between the wrapped film and the load, pulling the first arm to retain the film between the wrapped film and the load, and releasing the end portion of the film retained by the first arm to position and secure a first portion of the film between the wrapped film and the load. The load is wrapped further and subsequently a second arm is placed towards the load, and a layer of film is wrapped around the second arm so that the second arm is between the wrapped film and the load. A portion of film in the form of a rope is captured and retained by the first and second arms. The film is then cut into a rope shape, and the first arm retains one end of the cut film for subsequent wrapping of another load. The other end of the cut portion of the rope-shaped film is retained by the second arm, which is withdrawn from between the wrapped film and the load to place and secure a second portion of film between the wrapped film and the load. The arms are withdrawn along a relatively straight path, translating the arms laterally as they rotate, thereby reducing contact between at least the part of the arm retaining the tail of the film and the wrapped film.
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Document
ES2191363T3 describes a method of securing the rear end of a plastic film package for loads arranged on a platform, comprising the following steps: (a) forming a pocket in at least one of the end turns of the packaging, said pocket being formed by stretching a part of said turn in the longitudinal direction and causing said stretched part to be disposed at a suitable distance from the packaged load; (b) securing the film, in the area where the rear end of the packaging will be formed, by means of a clamp; characterised further by the steps of: (c) providing a secondary clamp that holds the film in the area where the rear end of the packaging will be formed; (d) cutting the film between said two clamps so that the main clamp supports the front end of the film for the packaging cycle of a subsequent load, while the secondary clamp holds the rear end of the packaged load; (e) inserting the secondary clamp holding the rear end of the packaging film into said pocket; (f) releasing the rear end of the film by means of said secondary clamp, inside said pocket, and removing said secondary clamp from the pocket; (g) contracting the bag containing the rear end of the film, shrinking it flat against the packaged load, gripping and firmly holding the aforementioned rear end of the packaging film.
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US2004045259A1 comprises an apparatus and method for wrapping a load under tension with a network of stretchable flexible wrapping material and then securing the wrapping material to the load by compressing the end of the flexible material into a rope-like configuration. The formed rope is wrapped around the load at least one turn. A second turn of the cord around the load is joined to the first cord with a mechanical twist tie around the two cords to prevent the load from unwrapping during transit and storage. A hot wire cutting mechanism cuts the cord and the two tied cords return to their position against the wrapped load by the force of the elastic wrap tension.
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However, none of the aforementioned documents indicates that the time required for the exterior box to come into contact with the load placed on the transport platform is controlled, the distance to be travelled to the load being controlled by: (i) predetermining the time required to travel the distance; (ii) the placement of one or more sensors that measure the distance between the load and the exterior box of the cord tying module; and (iii) the placement of one or more pressure sensors that are stimulated when the exterior box of the cord tying module comes into contact with the load that is being or has been wrapped.
Explanation of the invention
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It is an object of the present invention to provide an alternative for the final treatment of the cord after the load wrapping process that does not require the use of heat and, furthermore, is an element that moves towards the load and therefore does not compromise its integrity. The present invention is configured to be implemented in packaging machines in which it is the consumable, mounted on its feed structure, which rotates around the load, depositing itself on the product and covering it. All this is in accordance with the claims accompanying this descriptive report.
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More specifically, the automatic wrapping machine comprising a cord tying module, according to the present invention, comprises at least one wrapping carriage configured as a control structure for the consumable used to wrap a load placed on a transport platform, and where the wrapping carriage comprises the cord device configured to form a cord or cord from the consumable material, the free end of which is clamped and manipulated to form a tie in the wrapping of the load, and which is characterised in that the cord tying module comprises: a displacement base configured to bring a tying module closer to the load; and wherein once the tying module is in contact with the load, a cutting clamp and a holding clamp are deployed, wherein said holding clamp is configured to hold a free end of the cord of the consumable film before, during and after wrapping each load.
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Thanks to this structure, the cord tying module described advantageously does not need to use heat to perform its function, simplifying the nature of the system and reducing the amount of energy it requires.
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Throughout the description and claims, the word "comprising" and its variants are not intended to exclude other technical features, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be apparent in part from the invention and in part from the practice of the invention. The following examples and drawings are provided for illustration purposes and are not intended to limit the present invention. Furthermore, the invention covers all possible combinations of particular and preferred embodiments indicated herein.
Brief description of the drawings
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The following is a very brief description of a series of drawings that help to better understand the invention and that relate specifically to an embodiment of said invention, which is illustrated as a non-limiting example thereof.
- Figure 1
- shows a rotating arm and transport packaging machine.
- Figure 2
- is a front view showing the distribution of the subsystems of the invention.
- Figure 3
- shows the cord tying module of the invention assembled.
- Figure 4
- shows the tying moduleof the invention in Figure 3 deployed.
- Figure 5
- shows a first detailed view of the fastening module of Figure 4.
- Figure 6
- shows a second detailed view of the fastening module of Figure 4
- Figure 7
- shows a detailed view of the internal components of the cord tying module.
- Figure 8
- shows a second detailed view of the components of the cord tying module.
- Figure 9
- shows a detailed view of the components of the transport module.
- Figure 10
- shows a second detailed view of the components of the transport module.
- Figure 11
- shows another detailed view of the transport module components.
- Figure 12
- shows another detailed view of the transport module components.
- Figure 13
- shows a view of the assembly of the cord tying module on the transport module.
- Figure 14
- shows a view of the cord resting on the support.
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The following numerical references have been used in these figures:
- 1. Exterior box
- 2. Assembly lid
- 3. Cylinder 1
- 4. Cylinder 2
- 5. Cylinder 3
- 6. Cylinder 4
- 7. Assembly support. Cut
- 8. Polyurethane spiral tube
- 9. Guided ramp gauge
- 10. Cord cutting wheel guide
- 11. Cord clamp support
- 12. Oscillating mount
- 13. Blade
- 14. Cylinder rod
- 15. Articulated ball joint
- 16. Cord retention clamp base
- 17. Cord clamp reinforcement
- 18. Stop
- 19. Cutting clamp
- 20. Cutting-clamp support
- 21. Pressure plat
- 22. Sufridera support
- 23. Skid
- 24. Stop block
- 25. Blade clamp
- 26. Position bearing
- 27. Right displacement support
- 28. Displacement piston
- 29. Displacement rod fastening
- 30. Transport joint
- 31. Base guide displacement
- 32. Displacement rail
- 33. Wiring support
- 34. Piston rod displacement
- 35. Left displacement support
- 36. Clamped guide base
- 37. Wrapping carriage
- 38. Load/pallet
- 39. Film cord/rope
- 40. Load transport platform
Detailed explanation of an embodiment of the invention
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As can be seen in the accompanying figures, the present invention consists of an automatic wrapping machine comprising at least one wrapping carriage (37) configured as a consumable feed control structure, which houses the consumable used to wrap the load (38). This consumable is usually in the form of a reel or roll from which the plastic sheet (or other film-like wrapping material) is fed and placed around the load (38). The wrapping carriage (37) also contains the mechanical device responsible for forming a cord (39) or cord from the consumable material, which provides stability to the load and is the free piece of material (39) that is then clamped and manipulated by the tying module assembly. In an automatic wrapping system, the load (38) is placed on a platform (40) that transports it along the packaging line and on which the wrapping process is carried out.
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The cord tying module consists of four main subsystems:
- A. Displacement base
- B. Tying module
- C. Holding clamp
- D. Cutting clamp
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The cord tying module (subsystem B) is positioned away from the load at the start of the cycle. Once the cycle has started, the exterior box (1) is moved closer to the load by means of skids (31) in contact with a displacement rail (32), which in turn are supported on displacement bases (25) and (37). This movement towards the load is carried out by means of a piston that activates a rod (34), which is responsible for bringing the cord tying module closer to the load to be wrapped. This movement continues until contact is made with the load (38) or until the exterior box (1) makes contact with the transport joint (30).
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The displacement base (subassembly A) is responsible for bringing the cord tying module (subsystem B) closer to the load (38). Figures 9 to 13 show how the displacement base is coupled to the transport platform (40) so that part of the cord tying module is at least partially inserted into the platform (40) during operation. In a preferred embodiment, the displacement base (subassembly A) is bolted to the transport platform (40) so that its components cannot be separated unless the transport platform is dismantled. In another preferred embodiment, the displacement base (subassembly A) is located below the transport platform (40) with supports independent of it and its structures, although associated, are not fully integrated. In another preferred embodiment, the cord tying module is located on an independent platform placed in front of the transport platform. This platform, in its initial or rest position, is at a lower level than the load or the upper plane of the transport included in the line. This platform is equipped with motorised or pneumatic mechanisms that allow it to move upwards, placing it at the same level as the load or above the upper plane of the transport, allowing it to perform manoeuvres without being integrated into the transport.
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This system is controlled by monitoring the time required for the exterior box (1) to come into contact with the load (38) placed on the transport platform (40) of the line. This system can be implemented in various practical ways: (a) the base is moved by means of skids placed on the underside of the exterior box (1) of the cord tying module, and the distance to be travelled to the load is controlled by predetermining the time required to cover the distance; (b) the base is moved by means of skids placed on the underside of the exterior box (1) of the cord tying module, and the distance to be travelled to the load is controlled by placing one or more sensors that measure the distance between the load and the exterior box (1) of the cord tying module; and (c) the base is moved by means of skids placed on the bottom of the exterior box (1) of the cord tying module, and the distance to be travelled to the load is controlled by placing one or more pressure sensors that are stimulated when the exterior box (1) of the cord tying module comes into contact with the load that is being or is about to be wrapped.
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The cord tying module (subassembly B) is installed on or in front of end-of-line transport system (40). In a preferred embodiment, this transport platform (40) is composed of metal rollers connected to a traction system that causes them to rotate and consequently advances the load through the packaging line. In another preferred embodiment, the transport platform (40) does not contain rollers, but rather belts that are also driven by one or more mechanical systems to achieve a cyclical movement and advance the load through the packaging line.
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The system can be installed on both sides of the conveyor, with up to two modules operating simultaneously on machinery that has more than one wrapping carriage, in order to shorten cycles and increase production. As many ties as the user wishes can be made during the wrapping process.
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The operation of the cord tying system is independent of the size of the load (38) and the space it occupies on the packaging line conveyor, as the distance to be travelled by the exterior box (1), the size of the skids (23) and the travel rails (32) can be adjusted. This movement can be activated via a remote control, from the machine screen or automatically by taking commands from a recipe previously programmed into the equipment.
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Once in contact with the load, the cutting clamp (subassembly D) and holding clamp (subassembly C) are deployed, which are responsible for holding the free end of the film cord before, during and after wrapping each pallet. Either of these two sub-assemblies can be deployed at any time while the exterior box (1) is moving towards or away from the load in order to optimise production times. The holding clamp (sub-assembly C) holds the cord and moves towards the load. The wrapper with its wrapping carriage (37) then starts the packaging cycle, placing at least one turn of material over the load so that the cord overlaps with the film and the cord (39) dispensed by the wrapping carriage is kept between a film of material and the load itself.
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After this first revolution, the holding clamp opens when a pneumatic cylinder (4) is activated, releases the end of the cord and retracts into the exterior box (1), moving away from the load so that the module does not interfere with the wrapping process. The packaging process then continues according to the specifications or production requirements. Towards the end of the cycle, the wrapping carriage assembly forms a new cord that wraps around the load at least once.
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The wrapping carriage with the cord continues the wrapping cycle by depositing at least one strand of film or cord in front of the pressure plate (21), so that it is between a cord (39) and the load (38) being wrapped. Subassembly C, or the clamping device, is deployed so that it is next to subassembly D and in front of the cord (39) placed in the previous revolution of the machine. Advantageously, subassembly C does not press or deform the cord (39), allowing it to maintain its integrity and giving the tying process greater stability and repeatability.
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The wrapping carriage (37) with the cord (39) continues the wrapping cycle by depositing at least one cord (39) in front of the pressure plate(21), so that it is between the cutting clamp (19) and the upper part of the pressure plate(21), and in front of subassembly C so that it is between the cutting clamp (19) and the cord retention clamp base (16).
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The cutting clamp (19) proceeds to cut the cord by activating a pneumatic piston (6) that moves the pressure plate(21) upwards so that the cord (39) is trapped between the pressure plate(21) and the cutting clamp (19), causing the cord (39) to make contact with the cutting element (13) and cut the cord (39). Next, the pneumatic piston (5) is activated, which initiates the "folding" of subassembly D, i.e. the cutting clamp (19). Subassembly D also has a position bearing (26) located on at least one of its sides, which makes contact with the cord cutting wheel guide (10) containing the guide ramp gauge (9), allowing subassembly D to be retracted with a specific forward motion along the guiding ramp (9) (9). This movement pulls the cut end of the cord down and behind the cord (39) previously positioned in front of the pressure plate (21). In this way, the end of the cord (39) is placed in a secure position, locked by friction with the load (37) and prevented from escaping. Immediately afterwards, the pneumatic piston (6) is activated, releasing the cut end of the cord.
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In another embodiment, the pneumatic pistons (5) and (6) are activated simultaneously, achieving better coordination of the mechanical parts and a reduction in the tying process time.
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The holding clamp (subassembly C) is also activated by activating the pneumatic piston (4), which pushes the cord retention jaw base (16). Advantageously, the cord retention clamp base (16) contains two cord clamp reinforcements (17) that are also moved upwards until they make contact with and pass through two gaps in the cord clamp support (11), achieving a completely secure hold on the cord (39).
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The clamp (subassembly C) is then retracted into the exterior box (1) by activating the pneumatic cylinder (4), with the free end of the cord (39) secured between the cord retention clamp base (16) and the cord clamp support (11).
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The tying module (subassembly B) then moves away from the load (37) to its rest position so that it does not interfere with the movement of the wrapping carriage. The cord tying module described advantageously does not need to use heat to perform its function, simplifying the nature of the system and reducing the amount of energy it requires.
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In a non-limiting practical embodiment, the body (1) will incorporate a battery that powers the connection terminals (6), circulating the minimum current required to activate the cartridges (2).
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In a practical embodiment, the compartmentalised base (3) will be capable of moving to facilitate the exchange of cartridges (2).