ES3004610B2 - Load wrapping machine with maintenance system - Google Patents

Description

DESCRIPTION

Load wrapping machine with maintenance system

Technical field

The present invention relates to a load wrapping machine that includes a plastic film feeding system, as well as a plastic film cutting and welding system, so that these elements can be placed at a relatively close distance from the ground from where access to the plastic film feeding system is facilitated, as well as access to the cutting and welding system, so that service, repair or maintenance tasks can be carried out in a convenient, fast and safe manner.

State of the art

The state of the art describes various sheathing systems, either cold or heat shrink, with a system for placing certain parts of the equipment in a more favorable position for carrying out maintenance tasks.

Document EP2767479 describes that an upper frame can be moved from a working position to a maintenance position, which is at least substantially, and preferably completely, outside the workspace. "At least substantially outside the workspace" means that the upper frame is moved to a position outside the workspace such that an operator can access the devices mounted on the upper frame from outside the workspace. The operator does not have to enter the workspace to maintain the devices mounted on the upper frame or to insert a new tubular plastic film. The upper frame is not fixed to the main frame, nor is it a fixed part of it. During operation of the apparatus, the upper frame is held in a working position above a workspace. For maintenance of the equipment located on the upper frame, and for applying a new tubular plastic film to the upper frame, the upper frame can be moved to its maintenance position, in which it is easily accessible to an operator.

Document EP2069206 describes a wrapping device for packaging goods, specifically goods stacked on pallets or similar, with a tube-type plastic film. The device includes a plastic film feeding device with melting and cutting systems for generating and feeding a dome-shaped plastic film cover within a device frame. The plastic film feeding device works in conjunction with a coating device that moves vertically up and down within the device frame. The coating device is designed to grasp the plastic film cover and position it to cover goods located in the lower segment of the device frame. The device is characterized by having a plastic film feeding device that moves vertically within the device frame. This arrangement simplifies installation, maintenance, and repairs, specifically for the plastic film feeding device.

Document EP3838771 describes a machine for wrapping pallets using a stretchable plastic film plug, comprising: a main frame defining a working area of the machine; a traction device arranged to lower the plastic film plug onto the pallet; a feeding device arranged to feed the plastic film to the traction device; and a plastic film cutting and sealing device arranged to cut and seal the plastic film to obtain a plug closed at one end. The feeding device is movable along the frame between an operating position, located above the main frame, and a service position, in which the feeding device is located at a predetermined height from the ground on one side of the main frame. The feeding device comprises two deflectors, each of which is structured to grip two adjacent corners on opposite sides of the plastic film and to move the corners away from each other. The diverters are movable in an area outside the main frame along guides, structured to keep the feeder device out of the main frame and the working area, during movement between the working position and the service position.

Document EP3459868 describes a stretch film wrapping machine for pallet packaging, comprising a frame with four uprights, a plastic film positioning carriage movable in a vertical direction parallel to the uprights, adapted to grasp a length of tubular plastic film at one end and to place said length of plastic film onto the pallet, a plastic film preparation carriage adapted to move in the vertical direction comprising a feeding head arranged to take a portion of the tubular plastic film from a magazine, characterized in that the plastic film preparation carriage further comprises a translation structure for moving the feeding head in a direction orthogonal to the uprights, from a working position inside the frame to a holding position outside the frame and facing the same side of the magazine.

Document EP2792599 describes a pallet packaging machine comprising: a frame; a feeding device designed to remove a length of tubular plastic film from a storage compartment; a cutting and welding device designed to cut and weld a predetermined length of the tubular plastic film; and a vertically movable positioning device designed to grip the length of tubular plastic film at one end and fit the film onto a stack of items. The cutting and welding device is vertically movable, while the feeding device is fixed in an upper section of the frame, above the cutting and welding device and the positioning device.

Document EP3144233 describes a machine for wrapping pallets using a stretchable plastic film plug, comprising: a main frame defining a working area of the machine; a traction device arranged to lower the plastic film plug and place it onto the pallet; a feeding device arranged to feed the plastic film to the traction device; and a plastic film cutting and sealing device arranged to cut and seal the plastic film to obtain a plug closed at one end. The feeding device is movable along the frame between an operating position, located above the main frame, and a service position, in which the feeding device is located at a predetermined height from the ground, on one side of the main frame. The feeding device is movable in an area outside the main frame and, when changing from the operating position to the service position, the feeding device remains outside the main frame, without obstructing the working area.

Document EP3119680 describes an apparatus for wrapping goods stacked on a pallet, drawing a deformed cover of a reformable sheet material over the goods and allowing the deformed cover to reform to or towards its original shape, and securing the goods to the pallet and to each other. The apparatus comprises a frame defining sets of vertical legs and a top portion, a supply of the reformable sheet material in the form of a folded hose, and a plastic film feeding, welding, and cutting assembly for receiving the folded hose. The apparatus further comprises a vertically movable plastic film stretching frame that can be moved vertically relative to the plastic film feeding, welding, and cutting assembly from an upper position adjacent to the assembly to a lower position, in which the plastic film stretching frame draws the cover in its slightly deformed shape around the goods or packages and finally allows the cover to reform to or towards its original shape. The plastic film feeding, plastic film welding, and plastic film cutting assembly is fixed to one side of the frame to allow the plastic film feeding, plastic film welding, and plastic film cutting assembly to be moved from a horizontal working position on top of the frame to a vertical maintenance position outside the frame by rotating the plastic film feeding, plastic film welding, and plastic film cutting assembly from the horizontal working position to the vertical service position.

Document EP2336034 describes, in a first preferred embodiment, the device according to the invention, which can be designed as a shrink-wrapping device for shrink-wrapping a plastic film over a stack of products. In this case, the device conveniently features a shrink-wrapping frame which, as the coating device and as the plastic film feed head, is preferably movable in the direction of coating the plastic film and against the direction of coating the plastic film. The shrink-wrapping frame is electrically heated for shrink-wrapping a plastic film, for example. In a second preferred embodiment, the device according to the invention can also be a cap-stretching device. In this case, it is within the scope of the invention for the device to have a transverse stretching device and, preferably, a gathering device for gathering the plastic film. In such a device, the coating device can be used simultaneously as a transverse stretching device. It is within the scope of the invention that the plastic film source be a plastic film wound on a plastic film reel or a plastic film tube wound on a plastic film reel. The plastic film or the plastic film tube is conveyed from the plastic film source through the plastic film reservoir to the plastic film wrapping head. It is also within the scope of the invention that the plastic film be guided or held in the corresponding plastic film reel head. The at least one plastic film reservoir or the at least one plastic film reel is conveniently arranged in the lower portion of the device according to the invention.

Preferably, at least one plastic film tank or at least one roll of plastic film is arranged in the lower half of this height with respect to the height of the vertical masts.

Finally, document EP2588376 describes an Apparatus for packaging articles, in particular a stack of articles using a tubular plastic film, said apparatus comprising a plastic film feed device with a welding and cutting arrangement for producing and feeding a sleeve-shaped plastic film cover, and an adjustment device that interacts with the plastic film feed device, can be moved vertically up and down and is designed to grip the plastic film cover and adjust it over the articles, characterized in that the plastic film feed device is arranged so that it can be moved horizontally between an operating position and a holding position.

Explanation of the invention

An object of the present invention is a load wrapping machine that has the capability of positioning the plastic film feeding, cutting, and welding systems closer to the ground, so that operators can access the components of these systems more quickly and safely from ground level, whether for repair or maintenance. This object is achieved by the machine of the claims accompanying this specification.

The machine's structure comprises at least four pillars joined horizontally by metal profiles, which serve as supports and hold the rest of the machine's blocks, with the exception of the unwinder. The upper carriage is the block that includes the plastic film feeding and channeling systems, allowing the film to be transferred to the other blocks, which are positioned directly beneath it. It also includes the cutting and sealing system, positioned vertically aligned with the plastic film channeling system. The machine of the invention also includes the buffer system, which serves to store the already sealed and cut bags, as well as the bag opening or preparation system.

The plastic film is conveyed by the film feeding system to the cutting and sealing system. This system comprises a heating element, which heats the plastic until it melts and bonds the sheets of film together; and a cutting element, usually a blade, which is electrically or pneumatically activated to separate a specific length of plastic film from the rest of the roll. Located directly below the cutting and sealing system is a bag preparation element, which holds the bag ends and separates them, allowing the next element in the sleeve-making machine to access the plastic.

The next element placed vertically in the system is the plastic wrapping or sleeving carriage. This carriage consists of four limbs that hold the ends of the bag and extend them in opposite directions, increasing the distance between the faces of the plastic film segment and thus increasing its perimeter. This allows the film to be placed around the load, which is positioned on a base, preferably a pallet conveyor. This base is located within the structure of the wrapping machine of the present invention, which is referred to interchangeably as the wrapping zone or work zone.

Advantageously, the machine of the invention includes a maintenance maneuver and position, where some of the blocks that make up the machine are placed in a position close to the ground, so that they are more accessible to the machine operators and allow them to more comfortably perform tasks such as, but not limited to: (a) performing maintenance tasks on the various elements arranged in the block close to the ground; (b) removing or inserting the plastic film that serves as a consumable for the machine; (c) replacing blades; and (d) replacing or cleaning the welding bar.

In the present invention, it is proposed that the upper carriage, which includes the plastic film feeding system and the cutting and welding system, be able to descend until the systems are approximately 1000 mm above the ground. This lowers the system to a comfortable working height for the operator, who is standing on the ground. This maneuver is performed outside the frame of the sleeve-wrapping machine. This movement is activated and controlled by motors and executed via a system of chains or belts.

The operating and maintenance positions are located at the top and bottom of the machine, respectively. Once the upper carriage reaches the desired position, the motor brake engages, holding the block in that position. The carriage brake is not only engaged in the working and/or maintenance positions, but also allows for adjusting the sleeve travel distance. This gives the end user the ability to optimize the travel distance for loads at different heights, resulting in time savings for high-speed production runs.

The machine of the invention incorporates fall-prevention safety measures. This safety system consists of two basic elements: a perforated guide located on each leg of the structure, specifically on the inner face of the legs; and a pneumatic cylinder, positioned at each corner of the upper carriage, so that they maintain a direct relationship with the perforated guide located on the legs of the sleeve-wrapping machine. This cylinder is activated manually via the machine's control panel, or automatically due to the interruption of services associated with the equipment's operation, such as the power supply or compressed air flow.

The machine of the invention has the distinctive feature that the upper carriage comprises two main working positions: the operating position and the maintenance position. In the operating position, the upper carriage is located at the top of the machine. In this position, the machine is capable of continuously wrapping loads, fed from the consumable placed in the unwinders. Cutting, sealing, and opening the bag are also possible before the piercing operation on the loads located in the wrapping area.

In the maintenance position, the sleeve carriage descends until it reaches the lower part of the machine. This movement is achieved by a motor and a system of chains and belts located on the machine's legs. Then (or simultaneously), some of the devices mounted on the upper carriage advance from a fixed position within the machine frame to a temporary position outside the frame. Once the devices are outside the frame, the carriage lowers to a position close to the ground (approximately 1000 mm), allowing access to them from ground level. The sleeve carriage and the upper carriage move independently of each other, and although both blocks are synchronized to prevent collisions, their vertical movement within the machine structure is completely independent.

Throughout the description and claims, the word "comprises" 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 become apparent partly from the invention and partly from the practice of the invention. The following examples and drawings are provided for illustrative purposes and are not intended to restrict the present invention. Furthermore, the invention covers all possible combinations of the particular and preferred embodiments indicated herein.

Brief description of the drawings

Next, a series of drawings are briefly described that help to better understand the invention and that are expressly related to an embodiment of said invention, which is illustrated as a non-limiting example thereof.

FIG.1 shows an isometric view of the machine that is the subject of the invention.

FIG.2 shows a side view of the machine in figure 1.

FIG. 3 shows a side view of the upper carriage in the operating position.

Figure 4 shows two detailed views of the upper carriage in the operating position. Figure 5 shows a detailed view of the upper carriage.

Figure 6 shows a side view of the machine of the invention in its rest position. Figure 7 shows an isometric view of the machine of Figure 6.

FIG. 8 shows a detailed view of the upper carriage of the machine in Figures 6 and 7. FIG. 9 shows a side view of the upper carriage in Figure 8.

FIG.10 shows detailed isometric views of the cart in its resting position.

FIG.11 shows a detail of the upper carriage attachment.

FIG.12 shows a detailed view of the welding system.

FIG.13 shows views of the welding system coupling.

FIG.14 shows a side view of the machine in a service position.

FIG.15 shows a view of the machine with the plastic film advancing in a position outside the frame.

FIG.16 shows a detailed view of the machine in the service position.

FIG.17 shows a side view of the upper carriage with plastic film advancing out of the frame.

FIG.18 shows detailed views of the advance of the plastic film in the external position.

Figure 19 shows a detailed view of the advancing plastic film in the external position. Figure 20 shows a side view of the upper carriage in the operating position.

FIG.21 shows an isometric view of the upper carriage in service position.

The numerical references used in the figures are as follows:

1. Sleeve wrapping machine

2. Frame

3. Upper cart

4. Plastic film feeding system

5. Cutting and welding system

6. Bag opening system

7. Drafting or sheathing carriage

8. Unwinder

9. Coil

10. Conveyor in the sleeving area

11. Plastic film guide

12. Unwinder roller assembly

13. Plastic film feed rollers

14. Coil changing gearmotor

15. First coupling of the cutting and welding system

16. Wedge displacement pulley

17. Wedge displacement belt

18. Wedge movement motor

19. Wedge Guide

20. Axis of wedge displacement

21. Pneumatic cylinder

22. Clamping shaft

23. Sliding support

24. Lung

25. Lifting belt

26. Second coupling of the cutting and welding system

27. Welding bar

28. Lifting motor

Explanation of a detailed method of carrying out the invention

The accompanying figures show a practical embodiment of the machine (1) of the invention. This machine (1) is designed to cover a stack of articles, which in a preferred embodiment have been palletized on a platform, with plastic film from an unwinder (8). The machine (1) consists of pillars or legs joined together to form a frame (2) that serves as the main support for the other systems and devices that make up the machine and allow it to perform its functions.

This frame (2) includes an upper carriage (3) which in turn includes the plastic film feeding and advance system (4). At the bottom of the feeding system (4) is the cutting and sealing system (5) and placed directly below the latter, a bag opening system (6); it can also, optionally, include the air chamber device (24).

The plastic film feeding device (4) included in the upper carriage (3) of the machine of the invention (1) is capable of moving from an operating position (Fig. 2) within the sleeve area to a maintenance position (Fig. 20) outside the sleeve or work area. Similarly, the cutting and welding system (5) included in the upper carriage (3) of the machine (1) is capable of moving from an operating position (Fig. 2) within the sleeve area to a maintenance position (Fig. 20) outside the sleeve area.

It is worth noting that during the maneuvers of moving towards the outer part of the frame (2) and descending to a height reachable by a person from the ground, the plastic film feeding system (4) and the cutting and welding system (5) form a unit, causing these maneuvers to be executed synchronously by both systems, without being separated from each other. The plastic film feeding system has a guide system (19) and belt drive (17) that allows its horizontal movement relative to the machine frame (1), either towards the unwinder (8) or in the opposite direction. However, the welding and cutting system (5) does not have its own means of movement and must be attached to the plastic film feeding system (4) to perform the necessary movements and maneuvers to reach its operating position.

During normal operation of the machine (1) the upper carriage (3) is in a higher position of the frame (2), in this position, the plastic film is fed from the unwinder (8) which includes one or more reels (9), this plastic film passes through a set of rollers (12) included in the unwinder (8), it also passes through a plastic film guide (11) which is associated with the upper carriage (3) and from there it is redirected to the plastic film feeding system (4) where it is fed through a plurality of rollers (13) with a special surface finish so that it exerts the appropriate friction on the plastic film making it advance through the feeding system (4), these rollers are driven by a geared motor (14) following a clutch system.

Directly below the plastic film feeding system (4) is the cutting and sealing system (5), which seals the plastic film, forming a bag, and separates the bag section from the rest of the film. This system is fixed in this position, resting on bolts (15) that serve as the first coupling point (15) of the cutting and sealing system (5) to the upper carriage (3). Directly below, and also part of the upper carriage (3), is the bag opening system (6), which receives the section of plastic film, holds it at each corner, and separates the corners to provide enough space for the punching carriage (7) to access the bag, hold it, extend it, and then punch it over the load in the bagging area.

To transition from an operating position to a service position, the upper carriage (3) advances part of its systems out of the machine frame (2) (1). First, the plastic film feeding system (4) is retracted to a standby position, moving away from the plastic film guide (11) and the unwinder (8). This movement is accomplished by a pulley (16) and belt (17) driven by a motor (18). A shaft (20) connects both sides of the drive system to maintain uniform movement of the device along the linear guides (19) attached to the frame.

Also in a rest position, the cutting and welding system (5) rests on a first coupling (15) which holds it in place during normal operation of the sleeve-making machine. The first coupling (15) is inside the second coupling (26) of the cutting and welding system (5).

Once the plastic film feeding system (4) is in its rest position (Figs. 6-10), the pneumatic cylinders (21) associated with the cutting and welding system structure (5) are activated, releasing the clamping shaft (22) and causing it to rise above the plane on which the displacement support (23) is located. The plastic film feeding system (4) then moves back to its initial position so that the clamping shaft (22) is embedded in the displacement support (23). At this point, the pneumatic cylinders (21) are activated again, causing them to retract and lift the cutting and welding system (5) sufficiently to release the second coupling (26) from its rest position relative to the first coupling (15). Consequently, this results in the formation of a set of the plastic film feeding system (4) and the cutting and welding system (5), also making it so that from this moment on, the other maneuvers carried out by the plastic film feeding system (4) are also carried out by the cutting and welding system (5).

The feeding system (4), which, unlike the cutting and welding system (5), has an associated traction system, is set in motion again, but this time in the direction of the plastic film guide (11), which is located in the outer area of the frame (2) of the machine (1). This movement towards the outer area of the machine (1) is carried out by means of a traction system consisting of pulleys (16) and belts (17) driven by a motor (18) and following linear guides (19) fitted to the upper carriage (3).

Once secured to the outside of the frame (2) of the machine (1), the assembly consisting of the plastic film feeding system (4) and the cutting and welding system (5) can be moved vertically from a higher position to a lower position closer to the ground. This allows access to the components included in the plastic film feeding system (4) and the cutting and welding system (5) from the ground, making repair or maintenance tasks much easier and safer, as well as facilitating the process of changing the plastic film reel, which in state-of-the-art machines must be done from the top.

Vertical displacement is achieved through a lifting system with belts (25) located at each corner of the upper frame and driven by a geared motor (28) on the X and Z axes.

During the maneuvers required for the plastic film feeding system (4) and the cutting and sealing system (5) to maintain the same orientation, parallel to each other and horizontal to the frame (2) of the sleeve-wrapping machine (1). Once the upper carriage (3) descends to the service position, the orientation of the feeding (4) and cutting (5) systems is maintained.

The unwinder (8), which stores the plastic film reel(s) (9), is equipped with a means to collect or rewind the excess plastic film generated as the plastic film feeding system (4) descends to the ground. This keeps the excess plastic organized and prevents it from obstructing the various operations required to reach the operating position or from damaging other machine components. This means of rewinding the plastic during the movement of the plastic film feeding system (4) and the cutting and welding system (5) to the operating position can be a motor or an equivalent system.

In another preferred embodiment, the plastic film guide rollers (11) are located on opposite sides of the sleeve-wrapping machine (1), so that the plastic film feeding system (4) and the cutting and sealing system (5) can be moved outside the frame (2) of the machine (1) to either side, regardless of the position of the unwinder (8). In another preferred embodiment, the plastic film guide rollers (11) are not located on opposite sides of the sleeve-wrapping machine (1), but the guide (19) is extended sufficiently to allow the plastic film feeding system (4) and the cutting and sealing system (5) to be moved outside the frame (2) of the machine (1) to either side, regardless of the position of the unwinder (8).

An advantage of the invention is that the upper carriage (3) can be placed in a service position (Fig. 20), along with the plastic film feeding system (4) and the cutting and sealing system (5), without removing the load from the work area on the sleeve conveyor (10). To achieve this, the sleeve carriage (7) and the buffer (24) can be moved to the ends of the work area at least far enough to avoid colliding with a load within the area or with the sleeve conveyor (10).

Claims (10)

1. - Load wrapping machine (1) with maintenance system, configured to cover a stack of palletized items with a plastic film from at least one reel (9), comprises: a frame (2) on which an upper carriage (3) is located comprises, in turn: a plastic film feeding system (4); a cutting and welding system (5) located in the area immediately below the plastic film feeding system (4) and configured to seal the plastic sheet or film, turning it into a bag, as well as separating the formed bag from the rest of the plastic film; a bag opening system (6) located in the area immediately below the cutting and welding system (5) and configured to hold the bag formed in the cutting and welding system (5) by each of its corners and separate them from each other in such a way that there is sufficient space for a wrapping trolley (7) to access inside the bag, hold it, extend it and wrap it over the palletized load located in the wrapping area; wherein the plastic film feeding system (4), as well as the cutting and welding system (5) located on the upper carriage (3) are configured to move together from an operating position within a load wrapping area to a maintenance position outside the load wrapping area, in an area external to the frame (2); and wherein during the maneuvers required for the assembly of the plastic film feeding system (4) and the cutting and welding system (5) to move between the maintenance and service positions, both systems maintain the same orientation, parallel to each other, and horizontal with respect to the frame (2) of the wrapping machine (1); where the plastic film feeding system (4) comprises horizontal displacement means (16,17,18,19,20) relative to the frame (2) to move from the operating position to the maintenance position outside the load wrapping area; and which is characterized by the fact that The cutting and welding system (5) is coupled to the plastic film feeding system to move horizontally relative to the frame (2) to move from the operating position to the maintenance position outside the load wrapping area. 2. - The machine (1) according to claim 1, wherein in the operating position, the upper carriage (3) is located in a higher position of the frame (2); in this position, the plastic film is fed from the unwinder (8) which includes one or more reels (9), and wherein this plastic film passes through a set of rollers (12) included in the unwinder (8), also passes through a plastic film guide (11) which is associated with the upper carriage (3) and from there is redirected to the plastic film feeding system (4). 3. - The machine (1) according to claim 2 wherein the plastic film feeding system (4) is fed with plastic film through a plurality of rollers (13) having a surface finish configured to exert friction on the plastic film such that the film advances through the feeding system (4); and wherein the rollers (13) are driven by a geared motor (14). 4. - The machine (1) according to any one of the preceding claims, wherein the cutting and welding system (5) is fixed in the area immediately below the plastic film feeding system (4), resting on bolts configured as a coupling of the cutting and welding system (5) to the upper carriage (3). 5. - The machine (1) according to any one of the preceding claims, wherein, in order to move from the operating position to the holding position, the plastic film feeding system (4) comprises a traction system formed by a pair of pulleys (16) driven by a belt (17) and joined by a shaft (20) connected to a motor (18), such that the plastic film feeding system (4) is withdrawn to a waiting position in a direction opposite to that of the plastic film guide (11) and the unwinder (8) by means of linear guides (19) fixed to the frame (2) or of rollers of the plastic film guide (11) located on both opposite sides of the machine (1). 6. - The machine (1) of claim 5, wherein the cutting and welding system (5) is associated with pneumatic cylinders (21) configured to release a clamping shaft (22) movable with respect to a displacement support (23), such that the clamping shaft (22) is embedded in the displacement support (23) and allows the cutting and welding system (5) to be lifted until a second coupling (26) is released from its rest position relative to the first coupling (15), the cutting and welding system (5) being structurally coupled to the plastic film feeding system (4). 7. - The machine (1) of claim 6, wherein the assembly formed by the plastic film feeding system (4) and the cutting and welding system (5) is configured to move, by means of the traction system of the plastic film feeding system (4), towards the plastic film guide (11) located in the outer area of the frame (2) of the machine (1), the assembly formed by the plastic film feeding system (4) and the cutting and welding system (5) being arranged to perform a vertical movement from an upper position to a lower position close to the ground. 8. - The machine (1) according to claim 7, wherein the vertical displacement is carried out by means of a lifting system with belts (25) located at each corner of the upper frame and driven by a geared motor (28) on the X and Z axes. 9. - The machine (1) according to any one of the preceding claims, wherein once the upper carriage (3) descends to the service position the orientation of the feeding (4) and cutting (5) systems is maintained. 10. - The machine (1) according to any one of the preceding claims, wherein the unwinder (8) which is responsible for storing the plastic film reel(s) (9) is equipped with means to collect or "rewind" the excess plastic film generated when the plastic film feeding system (4) descends and brings it closer to the ground.