Patent Application
20230416017
The present invention relates to a device and a process for handling cardboard reels, especially cardboard reels used to feed machines for the production of cardboard tubes, in particular for making paper rolls with an internal tubular core. It is known that the production of logs of paper material, from which for example toilet paper rolls or kitchen paper rolls are obtained, involves feeding a paper web, formed by one or more overlapping plies, along a predetermined path along which various operations are carried out before proceeding with the formation of the logs, including a transversal pre-incision of the web to form pre-cut lines which subdivide it into tear-separable sheets. The formation of the logs normally involves the use of cardboard tubes, commonly called “cores” on the surface of which a predetermined amount of glue is distributed to allow the gluing of the paper web on the cores gradually introduced into the machine that produces the logs, commonly known as “rewinder”. Upon reaching the predetermined number of sheets wound on the core, the last sheet of the log being completed is separated from the first sheet of the subsequent log, for example by means of a jet of compressed air directed towards a corresponding pre-incision line. At this point, the log is unloaded from the rewinder. Patent EP1700805 describes a rewinding machine which works according to the above indicated operating scheme. The logs thus produced are then conveyed to a buffer which supplies one or more cutting-off machines by means of which the logs are transversely cut to obtain the rolls in the desired length.
The tubular cores are produced by means of machines commonly known as “tube-forming” machines configured to wind one or more cardboard webs around a mandrel creating a helical winding. Examples of tube-forming machines configured in this way are provided in EP3099481 and EP3212391B.
The reels, from which the cardboard webs are unwound, are loaded, with the aid of lifting devices controlled by an operator, onto special unwinding units that support the reels themselves during the production of the tubes. For this purpose, these reels are arranged, stacked on a pallet, in a parking station from which they must be picked up one at a time to be conveyed to the tube unwinding units. A frequently occurring drawback resides in the fact that the stacked reels tend to adhere to each other at the interface of the respective bases, this in relation to the fact that, in the production phase, the individual reels may be not perfectly detached from each other. Therefore, frequently, the operator assigned to picking up the reels is forced to exert a mechanical action on the reels to facilitate their detachment and therefore the picking up. This involves wasting time and risks for the safety of the operators.
The main object of the present invention is to obviate the aforementioned drawbacks. This result has been achieved, in accordance with the present invention, by adopting the idea of making a device and a method having the characteristics indicated in the independent claims. Other characteristics of the present invention are the subject of the dependent claims.
Thanks to the present invention, it is always possible to ensure the most correct detachment of each reel from the underlying reel of the stack arranged in the reel parking station enslaved to one or more tube forming machines using the same reels. Furthermore, a device in accordance with the present invention is relatively simple, both from a structural and a functional point of view, and helps to increase the efficiency of the cardboard tubes manufacturing process. In addition to this, the physical activity of the assigned operators is greatly reduced, which facilitates the activity of the operators themselves and increases the safety of the process.
These and further advantages and characteristics of the present invention will be better understood by every person skilled in the art thanks to the following description and the attached drawings, provided by way of example but not to be considered in a limiting sense, in which:
Reduced to its essential structure and with reference to the figures of the attached drawings, a device (D) according to the present invention is configured to operate on the individual reels (1) from a stack (2) of reels arranged in a parking station (P) enslaved to one or more tube forming machines (3) which use reels (1) to produce cardboard tubes. The reels (1) are formed by a predetermined amount of cardboard web wrapped around a central tubular core (1C). The stack (2) is formed by a predetermined number of overlapping reels (1). The tube forming machines (3) are machines known per se, for example of the type described in the documents cited above.
In the block diagram of
A device according to the present invention is configured and structured to facilitate the detachment of each reel (1) of the stack (2) from the underlying reel.
With reference to the example shown in
In the exemplary drawings of
The lower base (60) of the distributor (6) is integral with the upper base (80) of a box-shaped body (8) which is crossed by the tubular ducts (4, 5) and has a lower base shaped as a flange (81). The box-like body (8) is integral with a maneuvering portion (800) which can be moved to and from the stack (2) by means of a movement arm (200) as further described below. In the example shown in
On the lower side of the rod (45) formed by the coaxial ducts (4, 5) two plates (91, 92) are mounted, placed at a predetermined distance from each other, forming an upper plate (91) and a lower plate (92). The upper plate (91) includes a fixed upper flange (911) keyed on the rod (45), a movable lower flange (912) adapted to slide on the rod itself (45), and an elastic gasket (913) positioned between the flange fixed upper flange (911) and the lower movable flange (912) coaxially with the rod (45). Similarly, the lower plate (92) comprises a fixed lower flange (921) integral with the lower end of the rod (45), a movable upper flange (922) adapted to slide on the rod (45), and an elastic gasket (923) positioned between the fixed lower flange (921) and the movable upper flange (922) coaxially to the rod (45). For example, the fixed lower flange (921) is locked on the lower end of the rod (45) by means of a bolt (95). The outlet (42) of the internal duct (4) is between the movable flanges (912, 922) of the plates (91, 92). The drawings also show two ducts (420) that pneumatically connect the movable flanges (912, 922) with the outlet (42) of the duct (4). In practice, by introducing compressed air through the inlet (40), the movable flanges (912, 922) move in the direction of the respective fixed flanges (911, 921), each compressing the corresponding elastic gasket (913, 923) which, consequently, is forced to expand radially outwards.
The device by way of example represented in
In
The core surface engagement mechanism (1C) can be omitted.
The device described above, if it also includes the core engagement mechanism (1C), can be used as follows.
By means of the arm (200) the box-like body (8) with its lower base (81) is placed in contact with the upper base of the reel (1) higher than the stack (2). The contact is detected by means of a mechanical probe (not visible in the drawings). In this condition, the upper plate (91) is inside the core (1C) of the reel (1) with which said base (81) is in contact, while the plate (92) is inside the core (1C) of the underlying reel. In fact, the distance (k) between the plates (91, 92) is such that, once the base (81) is placed against the upper face of the reel (1) higher than the stack (2), the plates (91, 92) are one inside this reel and the other inside the underlying reel. In this phase, compressed air is introduced through the inlet (83), so the levers (100) are set back, that is, close to the bushing (104). At this point, compressed air is blown through the internal duct (4). This determines the movement of the movable lower flange (912) of the plate (91) towards the respective fixed flange (911) and, at the same time, the movement of the upper movable flange (922) of the plate (92) towards the respective fixed flange (921). Consequently, the gaskets (913, 923) are compressed and expand by adhering to the internal surface of the cores (1C) of the highest reel of the stack (2) and of the reel below it. In this way, a space (S) substantially impermeable to air is formed between the plates (91, 92). Then, compressed air is introduced through the external duct (5) which flows into the aforementioned space (S) and is released at the interface between the lower base of the reel in which the plate (91) is inserted and the upper base of the reel in which the plate (92) is inserted. Therefore, a pressure is produced in the space (S) between the plates (91) and (92) which determines the detachment of the upper reel from the lower reel.
Subsequently, the injection of compressed air into the internal duct (4), into the external duct (5) and through the inlet (83) is interrupted. With the interruption of the compressed air in the duct (4) the movable flanges of the plates (91, 92) return to their initial positions and the gaskets (913, 923) also return to their initial condition of non-contact with the cores (1C). In this phase, the supply of compressed air to the duct (5) is no longer necessary because the reels have already been detached due to the pressurization of the space (S) previously operated. The interruption of the compressed air supply through the inlet (83) arranged on the box-like body (8) causes the bushing (104) to lift, pushed upwards by the elastic member (106), and therefore the rotation of the levers (100) on the pins (103), whereby the toothed sectors (101) of the same levers (100) move away from the bushing (104) and engage the inner surface of the core (1C) of the upper reel of the stack (2). In this condition, the upper reel (1) of the stack, (2) is engaged by the arm (800) through the engagement mechanism which, in the example described above, is the mechanism comprising the levers (100). The arm (200) can then be led to an unwinder (30) with the reel (1) hooked to it. The release of the reel will be determined by a new introduction of compressed air through the inlet (83) which will cause the levers (100) to approach the bushing (104) and therefore the disengagement of the toothed sector of the same levers from the internal surface of the respective core (1C).
With reference to the embodiment example shown in
As previously stated, a device according to the present invention may not be provided with the core engagement mechanism (1C). In this case, the steps previously described in relation to the engagement of the cores (1C) do not take place and the device is used only to cause the detachment of the reels from the underlying reels of the stack by pressurizing the space (S) between the plates (91, 92). The transport of the reel thus detached, from the parking point (P) where the stack (2) is located to the unwinder (30) to which the reel is destined, can be carried out with already known methods, for example making use of the so-called “weightless” manipulators.
More generally, a device (D) for handling cardboard reels in accordance with the present invention is a device configured to engage stacked cardboard reels (1) and comprises a rod (45) on which are arranged:
In accordance with the present invention, the device (D) can also comprise a mechanism for engaging the reels with:
In accordance with a further embodiment of the invention, the device (D) may also comprise a mechanism for engaging the reels with:
The activation of said first and second units is controlled by the control unit (7) by activating the solenoid valves (41, 51, 830) in the desired sequence. In the diagram of
Preferably, said plates (91, 92) are enslaved to a first duct (4) which supplies compressed air through which the respective gaskets (913, 923) expand. Furthermore, preferably, the pressurization of the space (S) between the plates (91, 92) is achieved by means of a second conduit (5) coaxial and external to the first (4).
Preferably, in accordance with the present invention, the aforementioned rod (45) is constituted by the coaxial ducts (4) and (5).
Preferably, in accordance with the present invention, the actuation of the jaws (100) involves the use of an elastic member (106) cooperating with a pneumatic piston (107) by means of a guide (which in the previous example is made by the bushing 104) on which both the elastic body (106) and the pneumatic piston (107) act.
In accordance with the example described above, the axial direction (A9) coincides with the common axis of the ducts (4) and (5), while the opposite surfaces of the plates that delimit the pressurizable space (S) below and above are defined by movable flanges (912, 922).
Furthermore, in the example described with reference to the embodiment shown in
A possible way of pressurizing the space (S) between the plates (91, 92) consists in providing the duct (5) whose outlet is precisely in correspondence with the space (S). In the example described with reference to the embodiment shown in
A device according to the present invention can be used to implement an operating method comprising the following operating steps:
The aforementioned operating method may also include the following further operating phases;
Alternatively, the highest reel of the stack can be engaged on an external surface thereof, for example its upper face as previously described.
Preferably, in accordance with the above operating method, the radially expandable parts (913, 923) of the plates (91, 92) are elastic gaskets which expand radially when they are compressed and return to an initial unexpanded configuration when they are not compressed.
Furthermore, preferably, the compression of the said elastic gaskets is due to a crushing of the gaskets themselves between two opposite surfaces (911, 912; 921, 922) of the plates (91, 92), the said opposite surfaces being a fixed surface (911; 921) and a movable surface (912; 922) of each plate (91, 92) between which the gaskets (913, 923) are positioned. Preferably, said crushing is determined by the movement of said movable surfaces by means of compressed air which pushes each movable surface towards the respective fixed surface.
Preferably, in accordance with this operating method, the pressurization of said space (S) is performed by means of a duct (5) fed with compressed air and having an outlet in correspondence with the same space (S).
Furthermore, preferably, in accordance with the present operating method, the central tubular core (1C) is engaged from the inside by means of jaws (100) inserted in the same tubular core (1C) and adapted to exert a radial pressure on the internal surface of this last.
It is also advantageously provided that the highest reel of the stack is engaged on its upper face by means of a suction cup (300).
In practice, the details of execution can in any case vary in an equivalent manner as regards the individual elements described and illustrated, without thereby departing from the idea of the solution adopted and therefore remaining within the limits of the protection granted by this patent in accordance with the following claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102020000030644 | Dec 2020 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/IT2021/050400 | 12/9/2021 | WO |
