Unwinding unit

Abstract

The present invention relates to an unwinding unit comprising two or more unwinding stations (1) with respective shafts (11) for the rotation and fastening of the cores of the reels, characterised in that it comprises a central arm (14) between the two stations (1), said central arm ending in bidirectional motorised wheels (15) and being movable between the reels held by the stations (1).

Description

[0001] DESCRIPTION

[0002] Unwinding equipment

[0003] TECHNICAL SECTOR

[0004] This application relates to unwinding equipment for large rolls of cardboard or similar, and in particular to the unwinding mechanism and the splicers.

[0005] STATE OF THE ART

[0006] The state of the art is known for the existence of cardboard, paper, or similar reels that must be transported, unwound to perform continuous operations on the cardboard or similar, and then rewound onto reels. Generally, the sheets have a limited length that does not correspond to the desired length, and it is necessary to splice the reels (when one is finished, the next must continue) to continue the process as quickly as possible without stopping.

[0007] The applicant is not aware of any solution similar to the invention.

[0008] BRIEF EXPLANATION OF THE INVENTION

[0009] The invention relates to an unwinding device according to the claims. Its embodiments improve and solve problems in the art.

[0010] The equipment provides greater safety for production and maintenance personnel, with improved performance, which reduces overall manufacturing and operating costs. Among other reasons, it allows for the automation of operations that were previously performed manually.

[0011] The unwinding of each layer of laminated material is carried out in pairs of stations. Each station consists of two arms that hold a coil between them. At the lower end of each arm is the cone holder, which holds the coil cores or mandrels. Each station is suspended from a structure. Thus, each station is made up of two parts: the arms or cone holders, which move together and apart to grip or release the coils. The arms are suspended, pendulum-like, to absorb any vibration or movement. This unwinder is preferably suspended in the air, without contact with the ground, especially with the laminated material.

[0012] The invention is based primarily on the splicing system, which reduces the dimensions of the equipment, allowing it to be installed where other equipment does not fit.

[0013] The remainder of the report describes other particular realizations.

[0014] DESCRIPTION OF THE FIGURES

[0015] For a better understanding of the invention, a section of drawings is included containing the following:

[0016] Figure 1: General side view of a two-station unwinder and the corresponding sheet or strip splicing systems.

[0017] Figure 2: Detail of an unwinder and splicer with the adhesive applied to the band.

[0018] Figure 3: View of the different stages of splicing two sheets: A) the adhesive facing the first roller and the web ready for splicing, the splicing carriage lowering for contact; B) the paper pressing against the adhesive and cutting; C) the splicing unit raising with the already cut web; D) the splicing unit moving laterally and releasing the remainder.

[0019] MODES OF EMBODIMENT OF THE INVENTION

[0020] Below, a brief description is given of an embodiment of the invention, as an illustrative and non-limiting example thereof.

[0021] The embodiment shown in the figures comprises one or more unwinders with stations (1 ), generally two. Each station (1 ) is formed by a rotating shaft (11 ). The shaft (11 ) is formed in two parts (cone holders) that approach and separate, both being finished in a conical or truncated conical tip that helps to center and insert the shaft (11 ) into the core or mandrel of the coil from the side. The station (1 ) represented is arranged hanging to reduce contact with the ground.

[0022] The approach / retraction movement of the shafts (11 ) is carried out by electrical or pneumatic systems. Hydraulic systems are avoided to reduce the possibility of contamination or staining of the sheet with hydraulic oil. The shafts (11 ) can have an ejector that decouples the core or mandrel so it can fall or be collected. Each part of the shaft (11 ) is supported by a pendulum arm (13) so that it can absorb small shocks, vibrations, etc.

[0023] The unwinding unit shown has two parallel stations (1 ), each on a different structure. Between the unwinders (1 ) there is a central arm (14) that can move in one direction or the other to come into contact with the reels of each station (1 ). The central arm (14) is finished with wheels (15) motorized in both directions of rotation and has several functions:

[0024] The first function is an accelerator, where the central arm (14) accelerates the new coil when it is being changed. The second, once the change has been made, is to rewind the old coil so that the excess film returns to the tube. Once rewound, the old coil is released from the shaft (11) if it is to be replaced.

[0025] The central arm (14) can also move the corresponding reel so that a splice can be made between the end of the previous reel and the start of the new one. This retraction will be necessary to control how much adhesive is needed and what length of both sheets overlap. This allows overlapping splices to be made using double-sided adhesives, or in butt mode, using single-sided adhesives.

[0026] By being able to rotate the coil in one direction or another, the central arm (14) allows the operator to rotate and place the coil, without physical effort, in the correct position for applying the adhesive.

[0027] The central arm (14) may be counterweighted to facilitate the placement of the central arm (14) in the correct support position on the coil, generally by means of a motor.

[0028] For splicing the sheets of two consecutive reels, a support (16) is used near the station (1) where the free end of the sheet or band can be temporarily fixed. On this support (16) a cut is made in the sheet to ensure the cleanliness and shape of the edge and a layer of adhesive is placed. At the same time, a tamper (4) is used to press this free end against a support roller (5) of the band, immobilizing it. The support (16) and the support roller (5) are very close, in a preparation area. A second, mobile tensioning roller (6) makes it possible to ensure that the arrival of the band at the splicing unit is carried out at the optimal angle to avoid unwanted friction of the paper band on fixed parts of the machine.

[0029] For its part, a splicing carriage (3) moves above the support (16) comprising two rollers (31, 32), and is movable along a guide line (33). This guide line (33) is composed of three pieces on the stations (1 ): a central piece is fixed and some ends are movable vertically. The direction of the guide line (33) corresponds to the direction of movement of the unwound sheet or strip towards its use area. The first roller (31 ) is closest to the exit direction of the sheet and is always in contact with it. The second roller (32) only works with the sheet when the reel being unwound is further away from the point of use of the sheet. In figure 1 , only the first roller (31 ) is working. The splicing carriage (3) carries the clamp (4) and places it on the support or the support roller (5) when it is necessary to retain the sheet or strip.

[0030] Once the clamp (4) has pinched the sheet against the support roller (5) and the adhesive has been applied to the piece of sheet on the support (16), either manually or automatically (Figure 2), the central arm (14) moves the sheet backward, winding the corresponding station (1) until the adhesive is directed towards the splicing carriage (3) above the support roller (5). The splicing carriage (3) is positioned over the support roller (5) and presses one of the rollers (31,32) carrying the sheet from the other station (1) against it, so that the sheet is pressed against the adhesive. The roller (31,32) of the splicing carriage (3) that is pressed depends on which reel is to be unwound.

[0031] It can be seen by comparing Figures 2 and 3 that the preferred clamp (4) is made up of two parts. The first is a movable body (41 ), pulled by the splicing carriage (3) between two end positions corresponding to the support rollers (5), but which can move slightly with respect to the splicing carriage (3) to position themselves near its ends. The second are two actuators (42), one at each end of the splicing carriage (3), which actuate the movable body (41 ) to exert pressure on the corresponding support roller (5). This allows it to fulfill two functions. The actuator (42) that is not actuating the movable body can press the sheet or strip against the structure of the unwinder, to retain it. This can be especially clearly seen in Figure 2.In the realization of the figures, the splicing carriage (3) lowers the corresponding mobile end of the guide line (33), which has a cut and is connected to one or more pneumatic cylinders (figures 3A and 3B).

[0032] When the sheets have been properly adhered by the pressure of the support roller (5) and the first roller (31) or second roller (32), then the old strip is cut next to the tamper (4). For this purpose, it has a blade fixed to the body of the splicing unit. The old reel is then free to be rewound by the central arm (14) in contact with the reel. The splicing carriage (3) can return to its starting position, generally central, and the strip passes between the rollers (31, 32) on its way to the point of use.

[0033] All rollers, wheels, etc. have their rotation axes parallel to each other so that they can perform their function of moving the sheet or strip or making contact with each other.

Claims

CLAIMS 1. Unwinding equipment, comprising two or more unwinding stations (1 ) with respective axes (11 ) for rotating and holding the cores of the coils, characterized in that it comprises a central arm (14) between both stations (1 ), finished in wheels (15) motorized in both directions, and mobile between the coils carried by the stations (1 ).

2. Unwinding equipment, according to claim 1, characterized in that it comprises: a preparation area close to each station (1 ), with a support roller (5) and a support (16) for gripping the sheet of the coil and applying adhesive; at least one tamper (4) for pressing the sheet against the support roller (5); a splicing carriage (3), with two rollers (31, 32) for diverting the sheet towards the exit point of the equipment, mobile along a guide line (33), so that at least the roller (31, 32) closest to the exit point is mobile against the support roller (5).

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