Winding apparatus

Abstract

 An apparatus for rolling of a web of paper (4) on a bobbin (3) by winding it around a rigid core (5) which is supported by suspension means comprising two arms (6) with mandrels (7) at their ends which engage in the ends of the core (5). The arms (6) are connected in a rotatable manner to a support (8) with respect to which they can rotate to raise or lower the bobbin (3) with respect to the floor (18). At least one of the two arms (6) can translate horizontally in a direction transversal to the paper (4) in order to allow for the nearing or distancing of the spindles (7) and, thus, their disengagement or engagement with the core (5). Inside one or both of the arms (6), a motor (12) is provided which sets in rotation an axle (15) that is integral with the respective mandrel (7). The paper (4) is rolled on the bobbin (3) as the bobbin gradually is lifted from the floor (18).

Description

[0001] The present invention relates to the field of paper and more precisely to an apparatus for rolling a web of paper on a bobbin as it comes out of a machine for its processing and/or printing.

[0002] In machines for processing or printing on paper, the paper is often rolled on a bobbin at the output of the machine as an alternative to when it is cut into sheets.

[0003] In the existing machines, the rolling is carried out in one of two ways:

• with tangential dragging
• with axial dragging.

[0004] In the first case, the bobbin is mounted on a core which is held by two protruding tapered shafts mounted on idle rotatable supports. The rolling takes place by means of motorized dragging rollers which cause rotation by a tangential action on the paper. The bobbin, which is formed starting from a core large enough to make rolling possible in an initial step, gradually increases in diameter. Its growing size is controlled by a mechanical gauge formed by an arm which progressively varies its angulation and has a roller at one end in physical contact with the paper. The pulling of the paper is measured by means of load cells located on the supports of the bodies which pull the paper.

[0005] In axially dragged winding apparatus, widely used in the paper processing industry, the bobbin is suspended on a motorized expanding mandrel which puts it into rotation. The problem of this system lies in its dimensions and cost as well as in the fact that the mandrel must be of a significant weight, thus making it also necessary to use a core having a diameter large enough to be put on the mandrel and robust enough to withstand the internal forces of expansion. The core is usually formed in compressed cardboard that is sufficiently thick and not reusable.

[0006] In both cases, means, such as hoists or lift trucks, must be provided for which are able to remove the bobbin from the expanding mandrel or from the tapered shafts and deposit it on the floor or on a shelf. With the system of tangential dragging, sometimes the support tapered shafts are mounted at such a height that the bobbin, when the rolling is completed, almost touches the floor, so that it does not require discharge means. However, in many cases, the bobbin does not reach the diameter which allows for its direct unloading onto the floor and in such cases it is, therefore, equally as necessary to provide discharge means.

[0007] Sometimes, the paper to be rolled in a bobbin comes out of the machine operating upstream already taut. Often, however, it is not taut and a loop is provided that is controlled, for example, by signals coming from ultrasound sensors that command the acceleration or deceleration of the tangential draggers or of the mandrel. In this latter case, it is necessary to provide large stretching means which must exert a constant pull on the paper to make the rolling possible.

[0008] One object of the present invention is to provide an apparatus for rolling a web of paper on a bobbin which is extremely simple to construct and which makes it possible to drag the core axially at a controlled speed without requiring an expanding mandrel.

[0009] A second object of the present invention is to provide an apparatus for rolling a web of paper on a bobbin in which it is possible to determine the size of the bobbin without having to use diameter sensors.

[0010] A further object of the present invention is to provide an apparatus for rolling a web of paper on a bobbin which makes it possible to work with paper that is not taut without having to use large stretching systems or gauges of the stretch of the paper.

[0011] A final object of the present invention is to provide an apparatus for rolling a web of paper on a bobbin which can also advantageously work to unroll the paper from a bobbin.

[0012] These and other objects are accomplished by the apparatus according to the present invention for rolling a web of paper on a bobbin, whose novel feature is that the suspension means of the bobbin comprise a pair of arms connected in a rotatable manner to a support located at the output of the paper processing machine. A rigid core rotationally engages between the ends of the arms and with axial dragging mandrels.

[0013] At least one of said mandrels is set in rotation by motorized dragging means inside the arms. Each mandrel engages with the core only at its ends by reciprocal engagement means. Preferably, at least one encoder is provided to measure the linear development of the paper by means of the number of rotations made by the core.

[0014] In cases in which the paper is not taut when it reaches the rolling apparatus, stretching means are provided for it which preferably comprise two successive pairs of dragging rollers, the second having a slightly greater surface speed than the first.

[0015] The direction of rotation of the motorized dragging means of the or each mandrel can be reversible so that the apparatus is able to work also to unroll the paper.

[0016] Further characteristics and/or advantages of the apparatus according to the invention will become apparent in the following description of one of its possible embodiments, given as an example and not limitative, with reference to the attached drawings in which:

• figure 1 is a schematic view of the end portion of a processing and/or printing line of a web of paper rolled on a bobbin with the apparatus according to the present invention;
• figures 2, 3 and 4 are respectively a side elevated view, a top plan view and a perspective view of an apparatus for rolling a web of paper on a bobbin according to the invention;
• figure 5 is a scrap longitudinal sectional view of one of the arms of the apparatus according to the present invention.

[0017] With reference to figure 1, at the output of a processing and/or printing line, indicated with 1, an apparatus 2 according to the invention is provided for the rolling of a web 4 of paper on a bobbin 3.

[0018] Bobbin 3, as can be seen best in figures 2, 3 and 4, is rolled on a core 5 supported by suspension means comprising two arms 6 having mandrels 7 at their ends which engage on core 5 which, preferably, is a tubular core in rigid plastic which could advantageously be recycled plastic.

[0019] Arms 6 are rotationally connected to a support 8 with respect to which they can rotate in such a way as to raise or lower bobbin 3 from or toward the floor. Furthermore, at least one of the two arms 6 can translate horizontally in a direction transversal to the paper in order to make possible the nearing or distancing of mandrels 7 and thus their disengagement from or engagement with core 5.

[0020] One detail of the type of engagement on the mandrels can be seen in figure 5, wherein core 5 has grooves 10 at its ends, spaced at a circumferential distance of 90° from one another, in which teeth 11 provided on mandrel 7 engage.

[0021] With further reference to figure 5, inside one or both of arms 6, a motor 12 is provided with a reduction gear 13 which sets in rotation, by means of a taper fit 14, an axle 15 integral with mandrel 7.

[0022] Also integral with 15 is an encoder 16 which is electrically connected to a computer (not shown) which controls the speed of motor 12 and the angular position of arms 6 by means of motors 17 (partially visible in figures 1 to 4).

[0023] According to a preferred embodiment of the invention, web of paper 4 is rolled on bobbin 3 in such a way that the latter gradually lifts itself from floor 18 remaining close to it but never coming into contact with it. In fact, by means of encoder 16, it is possible to automatically calculate the diameter of bobbin 3 in an indirect manner by a simple mathematical correlation between the rotation of core 5 and the linear development of the paper being rolled on it.

[0024] At the completion of the rolling, or at any intentional or unintentional interruption of the rolling, bobbin 3 will always be at a minimum height off floor 18, so that the lowering time of arms 6 and spreading time of mandrels 7 is minimal, thus making it possible to remove said bobbin and immediately replace it with a new core on which to roll the following bobbin.

[0025] Paper 4 comes from a loop, indicated with 19 in figure 2, which is controlled by photoelectric cell sensors along lines 20 and is located directly upstream from apparatus 2. Paper 4 is then made taut in order to allow for its rolling on bobbin 5 thanks to the presence of a known stretching apparatus. This is preferably a paper feeding apparatus comprising two pairs of dragging rollers located inside support 8 and having slightly different speeds from one another, as described in European patent application 0695714 in the name of the present applicant and for this reason not shown and described in detail. More precisely, the first pair is placed upstream and has a rotational speed slightly slower than the second pair which, having a slightly faster rotational speed, pulls the paper taut independently of whether upstream from the first pair of rollers the paper is taut or not. The presence of these two pairs of dragging rollers also makes it possible to control the pulling of the paper without having to use load cells as is necessary in the known technology. In fact, as described in the cited patent application, the two pairs of dragging rollers are operated by torque controlled motors, which respond as a function of the pull of the paper, automatically bringing the tension to normal values without the risk of tearing the paper.

[0026] The main advantages of the apparatus described above are, therefore, the following:

• bobbin 3 always stays close to floor 18, with the consequence that, at the completion of rolling, the discharge time is minimized, whatever the final diameter of bobbin 3 is, without need for other discharge means;
• gauges are not necessary for measuring the size of the bobbin, since its diameter is calculated automatically;
• load cells are not necessary to control the stretch of the paper;
• tangential dragging rollers are not necessary and, consequently, the costs of the apparatus are reduced;
• the axial dragging is accomplished in a much simpler manner than in the case of expanding mandrels.

[0027] The apparatus described above, finally, has the advantage that it can also be used to unroll paper from a bobbin with the simple inversion of the direction of rotation of motor 12. Such unrolling can be needed when, for instance, during rolling, the inversion of movement is required for the processing or printing of the paper. The use of the apparatus for unrolling can also be systematic, with the advantage that the same apparatus used for a certain period of time for rolling at the output of a machine can be moved to the input for unrolling.

[0028] The above-described advantages are also obtained when the apparatus is used for unrolling because the bobbin does not require lifting means to be loaded and unloaded since it is always very near to the floor, ready to be rapidly removed for any urgent change of the type of paper which may be necessary.

Claims

1. Apparatus for rolling a web of paper (4) on a bobbin (3) at the output of a machine (1) for processing and/or printing the paper, comprising a core (5) for sustaining said bobbin (3), means for the suspension and axial dragging of said core (5) for sustaining the bobbin (3), characterized in that said means for suspension and axial dragging of said core (5) comprise a support (8) provided for at the output of said machine (1), a pair of arms (6) connected in a rotatable manner to said support (8), gripping mandrels (7) of which at least one is motorized provided for at the ends of said arms (6), said core (5) extending between said arms (6) and engaging at its ends with said gripping mandrels (7).

2. Apparatus according to claim 1, wherein one or each of said arms (6) comprises inside motorized dragging means (12, 13, 14, 15) connected with the or each motorized mandrel (7).

3. Apparatus according to claim 2, wherein said motorized dragging means comprise an encoder (16) integral with the or each mandrel (7).

4. Apparatus according to claim 1, wherein said support comprises a control unit and motors (17) operated by said control unit, said arms (6) being connected in a rotatable manner to said support (8) and put in rotation by said motors (17).

5. Apparatus according to claim 4, wherein one or each of said arms (6) comprises inside motorized dragging means (12, 13, 14, 15) connected with the or each motorized mandrel (7), said motorized dragging means comprising an encoder (16) integral with the or each mandrel (7) and said motors (17) putting in rotation said arms (6) by the signal coming from said encoder (16).

6. Apparatus according to claim 1, wherein said core (5) comprises a rigid tube having ends engaging in said mandrels (7), said ends and said mandrels comprising reciprocally fitting toothed couplings (10,11).

7. Apparatus according to claim 1, wherein feeding and stretching means for the paper are provided in said support.

8. Apparatus according to claim 7, wherein said feeding and stretching means comprise a first and second pair of successive dragging rollers, the first pair having a slower rotating speed and being placed upstream from the second pair.

9. Apparatus according to claim 8, wherein said pairs of dragging rollers are set in rotation by torque controlled motors.

10. Apparatus according claim 1, wherein the or each motorized mandrel is connected with motorized dragging means having a reversible direction of rotation, whereby said web (4) can be also unrolled from said bobbin (3).

Drawing