BRPI0510667B1 - ROLLER WITH INTERCHANGEABLE GLOVE FOR RELIEF RECORDING UNITS AND RELIEF RECORDING UNITS UNDERSTANDING SAID ROLL - Google Patents

Description

Report of the Invention Patent for "ROLLER WITH EXCHANGEABLE GLOVE FOR RELEVANT RECORDING UNITS AND RELEVANT RECORDING UNITS UNDERSTANDING THE ROLL". Technical Field The present invention relates to machines or devices for embossing fabric or laminated materials, in particular though not exclusively paper, especially tissue paper, of the type used to produce toilet paper rolls, kitchen towels, tissues and paper. napkins or the like. Prior Art In the processing of fabric or laminate materials, such as and in particular tissue paper, a so-called embossing process is often performed, wherein the material is fed through a step between two rollers provided with protrusions and / or protrusions, or one provided with protrusions and the other with a smooth, elastic surface, and yet again between a protruding roller and the other provided with corresponding cavities. Passing through the step between the two rollers (which may or may not be pressed together depending on the material used and the surface morphology of the rollers) the material is permanently deformed with partial rupture of the fibers of which it is composed. Embossing produces bulges in the material in a way that corresponds to the shape of the roll bumps or embossing rollers used. Embossing is used above all in the field of tissue paper conversion for particular technical-functional effects such as increased softness, increased thickness, increased absorbency and also for decorative effects. The purpose of embossing may also be to join two or more folds together, or to prepare one or more folds to receive a glue whereby the two or more folds are joined by laminating them between two embossing rollers, between an embossing roller and a lamination roller or in any suitable manner.

Examples of embossing units in various configurations are described in U.S. No. 6,578,617, in US Pat. 6,470,945, in European Patent No. 1,075,387, in European Patent No. 370,972 and many other patents belonging to the same technical field.

Recently, the need to customize the product has been increasingly felt, especially in the field of tissue paper conversion. Several manufacturers wish to customize their product using particular patterns produced by embossing, optionally combined with background embossing that provide the product with special technical-functional features. Frequently, manufacturers of tissue paper items want to offer their customers products characterized by different and varying patterns. Embossing the embossing rollers is an extremely expensive operation and therefore these rollers are very expensive. The need to achieve different, interchangeable patterns is therefore a major investment for the paper converter, which must have numerous embossing rolls. In order to reduce the incidence of these costs, embossing systems have been designed in which the embossing roller is composed of a central core and an interchangeable sleeve. In this way, different interchangeable gloves can be mounted on the same core to use various alternative patterns.

Embossing rollers composed of a central core and an interchangeable sleeve have some constructional problems, mainly deriving from the difficulty of properly securing the sleeve to the central core, also in view of the very high mechanical stresses to which the components are subjected during operation.

A further critical aspect is the need to produce the interchangeable sleeves and surface core that correspond to each other to ensure the concentricity between the axis of rotation and the outer cylindrical surface of the interchangeable sleeve.

Embossing roller embodiments comprising an interchangeable shaft and sleeve with different mechanisms for securing the sleeve to the shaft are described in EP-A-0.836.928, WO-A-03/045679 and WO-A-03/45680. .

OBJECTS AND SUMMARY OF THE INVENTION The object of the present invention is to provide a novel type of interchangeable glove embossing roll which is particularly safe with respect to reciprocal clamping between the glove and the central axis.

Essentially, the invention relates to an embossing roll for processing a fabric material comprising a central axis and a removable and interchangeable outer sleeve, the interchangeable sleeve having an essentially cylindrical outer surface provided with protuberances and / or cavity, characterized in that said shaft has radially expandable elements for securing the glove.

Expandable axles are known. They are used in the paper converting or converting other fabric materials industry to retain tubular cores, typically made of cardboard or similar materials around which the paper is wrapped, or from which the fabric material is unwound to forming bobbins, or for unwinding bobbins of fabric material. An example of such an expandable shaft is described in GB-A-2,388,886. These axles usually have a pneumatic drive system of the expandable elements disposed on the cylindrical surface thereof. The use of such expandable shafts to produce embossing rollers with an interchangeable sleeve is not known.

Advantageously, according to a preferred embodiment of the invention, the radially expandable elements are controlled by mechanical elements, in turn operated by, for example, one or more hydraulic or preferably pneumatic piston-cylinder actuators, preferably arranged on the one or both ends of the expandable shaft.

In a particularly advantageous embodiment of the invention, the expandable elements comprise a plurality of expandable blocks arranged on the shaft. Preferably, the expandable blocks are of limited length substantially less than the axial length of the expandable shaft.

Advantageously, these expandable blocks are distributed according to annular arrangements aligned on said expandable axis. In practice, a plurality of annular rings are provided along the length of the expandable axis, for example expandable block annular rings 5-10, with a mechanism within the axis that causes essentially simultaneous retraction of all blocks when the interchangeable sleeve requires be inserted into or removed from the shaft.

For efficient and safe subjection, in a particular embodiment of the invention the expandable blocks are controlled by risers within the shaft. Uprights can be associated with spring mechanisms that tension the uprights in a radial position, corresponding to the maximum expansion position of the blocks, while one or more actuators are provided to compress the springs causing oscillation into the uprights, and consequently retraction of the uprights. expandable blocks to allow movement to insert and / or remove the glove.

Additional advantageous features and embodiments of the roll according to the invention are set forth in the appended claims and should be described in detail with reference to an exemplary embodiment. These features may also be implemented on an expandable shaft to which a different element is attached with respect to an interchangeable sleeve.

In a different aspect, the invention relates to an embossing unit comprising at least one embossing roll produced as described above.

According to yet another aspect, an expandable shaft is provided which can be used as the inner axis of an interchangeable sleeve embossing roller comprising a tube in which the radially expandable elements are arranged and controlled by elements. mechanics inside the tube. The expandable shaft elements may include a plurality of expandable blocks arranged, for example, in accordance with annular arrangements distributed more or less evenly along the longitudinal extent of the shaft. Advantageously, the expandable blocks can be controlled by mullions within the tube forming the main shaft body. In general, the expandable shaft according to the invention may have one or more of the features described hereinafter with reference to an example of applying said shaft to produce an embossing roll. These features can be combined in various ways with each other to produce an expandable shaft that can also be advantageously applied in other uses.

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be better understood by following the description and accompanying the drawing showing a non-limiting practical embodiment of said invention. In the drawing: Figures 1 and 2 schematically show two embodiments of embossing-laminating units in which the invention may be incorporated; Figures 3A and 3B show two parts of an expandable shaft in a longitudinal section; Figure 4 shows an expandable shaft portion in a longitudinal section and in expanded condition; and Figure 5 shows a cross section according to VV in Figure 3. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION Figures 1 and 2 schematically show two embossing-laminating units of different configuration in which the rollers produced with one shaft and Interchangeable glove according to the invention may be used. It should be understood that the embossing-laminating units in Figures 1 and 2 are only two examples of possible machinery in which the invention may be advantageously used.

Referring to Figure 1, the embossing-laminating unit, indicated as a whole with 1, comprises a first embossing roll 3 and a second embossing roll 5 with parallel axes forming a pitch therebetween. Embossing rollers 3 and 5, which are provided on the surfaces thereof with notch protuberances using any available technique, cooperate with a corresponding pressure roller 7 and 9. Pressure rollers 7 and 9 are They are coated with an elastic material, such as plastic or rubber, and have a smooth outer surface.

Two folds V1 and V3 of fabric material, such as tissue paper, are fed within the steps between rollers 3 and 7 and between rollers 5 and 9, respectively. In this way the two folds V1 and V3 are embossed as a result of the pressure exerted by the embossing rollers 3 and 5 against the elastic surfaces of the rollers 7 and 9. In the pro-tuberances produced on the bend V1 by the embossing roll protrusions in relief 3, a glue is applied by means of a gluing unit 11 of the known type shown schematically in the figure. In the step between embossing rollers 3 and 5 the two folds are laminated together by pressing them at the level of the corresponding protrusions or protrusions of rollers 3 and 5. Alternatively, the two rollers 3 and 5 may be arranged with their compressed protuberances, that is, with the roll protuberances 5 placed opposite the cavities between the roll protuberances 3, or at a distance from each other and in any case without reciprocal contact between the protuberances. In this case, the two folds V1 and V3 are not laminated between rollers 3 and 5, but between roll 3 and a second laminating roll 13.

Despite the embossing and lamination technique used, a multi-ply N material composed of two ply V1 and V3, embossed and glued together, is obtained at the exit of the embossing unit. Each fold can in turn be composed of more than one layer.

In the embodiment of FIG. 2, the embossing-laminating unit indicated here with 21 comprises a main relay embossing roller 23 cooperating with a pressure roller 25 coated with an elastic material such as rubber and having an essentially smooth surface. A laminating roll 27 with a smooth, rigid or elastic surface, although advantageously with a stiffness greater than the cylindrical surface of the pressure roll, also cooperates with the embossing roll 23 provided with protrusions 23P.

A first fold of fabric material V1 is fed around the pressure roller 25 through the step formed by this roller and embossing roller 23. Before passing through this fabric fabric material V1 passes through a secondary embossing unit, indicated as a whole with 29, and composed of a embossing cylinder or roller 31, provided with protrusions or protrusions 31P, and cooperating with a pressure roller 33 coated with rubber or other elastic material.

A second fold of fabric material V3 is fed in the step between the embossing roll 23 and the laminating roll 27. In this step, the fold V3 is glued against the embossed fold V1 on the protrusions or protrusions of which produced by the protrusions 23P of the embossing roll 23, a glue has been applied by means of a gluing unit 30. The fold V3 may also advantageously be pre-embossed by means of an embossing roll 41 provided with protrusions 41P and cooperating with each other. a pressure roller 43 coated with an elastic material such as rubber or plastic.

The embodiments of these embossing-lamination units illustrated by way of examples are described in greater detail in WO-A-99/41064 and WO-A-99/44814. which should be referred to for further details.

Embossing rollers 3, 5, 23, and optionally also embossing rollers 31 and 41 can be produced according to the invention, with an expandable shaft on which interchangeable sleeves with different embossing patterns on relief, that is, varying protrusions or protrusions, may be alternatively placed and secured. The shape of the expandable shaft is shown in particular in Figures 3A, 3B, 4 and 5, where the shaft and interchangeable sleeve assembly (forming the embossing roll) is indicated with 3, while 51 indicates the interchangeable sleeve provided with protrusions, indicated here with 51P, and forming the protrusions of the embossing roll. The expandable shaft is indicated as a whole with 53. The expandable shaft 53 comprises a tube 55 as the main element, fixed at the ends of which are rods or ends 57 and 59. The expandable elements or blocks 61 are arranged on the surface of the tube 55. according to annular groupings. Arranged along the axial extension of the expandable shaft 53 is a plurality of annular arrangements of these blocks 61, the various arrangements being essentially equivalent to one another and being configured as shown in particular in the cross section in Figure 5.

In substance, each annular block arrangement 61 forms a cylindrical ring, and each block has an outer surface 61A and an inner surface 61B, both cylindrical, surface 61B having a radius essentially identical to the radius of tube 55, while surface 61A has a radius of curvature essentially identical to the radius of the inner surface of the interchangeable sleeve to be secured to the axis 53.

Each block 61 is axially held by stop members 63 which prevent axial movement of said blocks. Furthermore, the retaining element 65 is provided to limit possible radial movement of said blocks. The blocks 61 of each annular block arrangement are resiliently subjected to the outer surface of tube 55 by a pair of coil springs 67 wound around the axis of tube 55.

Each block 61 is associated with an upright 69, a sphere 71 being interposed between the distal (i.e. radially outermost) end of the upright 69 and the corresponding block 61. The uprights 69 can take two end positions: the first inclined position is 3A, 3B is a retracted arrangement of blocks 61; the second position, wherein the blocks 61 are in the extracted position, is shown in figure 4 and, in this arrangement, the mullions 69 are arranged in an essentially radial position.

As will be explained hereinafter, the position shown in figure 4 is one in which the mullions 69 and blocks 61 are normally held, in the absence of the interchangeable outer sleeve 51, by elastic elements housed within the axis 53. The retracted position in figures 3A 3B is taken to insert the sleeve 51 by means of a pneumatic actuator, or preferably, as in the illustrated example, a pair of pneumatic actuators disposed at the ends of the shaft and illustrated subsequently. When the interchangeable sleeve is mounted on shaft 53, the blocks 61 are arranged in a slightly more retracted position with respect to one in Figure 4, when the inside diameter of the sleeve 51 is smaller than the outside diameter of the surface defined by the blocks 61 in its maximum expansion condition in order to ensure proper glove attachment.

Within the tube 55, at the level of each annular group or annular block arrangement 61, are two flanges 73, 75 secured against the inner cylindrical surface of the tube 55 by tapered rings 77, 79 and counterbones 81 which are held in pairs by each other. threaded rods 83. The arrangement is such that after mounting the flanges 73, 75 of each pair are rigidly secured within the pipe 55. Rigidly constrained to each pair of flanges 73, 75 is a bushing 85 rigidly connected to said flanges. flanges. Each bushing 85 has an inner annular shoulder or projection 87, against which an elastic element, in the form of a coil compression spring 89, reacts, said spring being maintained in a condition at least partially compressed between the shoulder 87 and a projection. ring 91 produced in a corresponding hollow rod or pin 93. Pin 93 is threadedly secured to a flange 95 which moves axially integral with pin 93.

Produced on the outer surface of bushing 85 are rails, in the same number as the number of expandable blocks 61, indicated with 85A, for corresponding groups of rollers 97 or other swivel bodies of suitable shape. The rollers 97 associated with each rail 85A act as swivel bodies for sliding respective shoes 99, each of which is secured by means of an element 101 on the common flange 95. In this way, the sliding of pin 93 into bushing 85 and thus sliding flange 95 causes corresponding and simultaneous movement in an axial direction of the shoes 99.

In each shoe 99 is hinged the end of a relative mullion 69, opposite the end of the mullion secured by the ball 71 in block 61. In this way, the simultaneous sliding of the shoes 99 causes the mullions 69 to oscillate and translate and thus to expand. or simultaneously retracting the expandable blocks 61 when pin 93 moves in accordance with or in contrast to the action of the compression spring 89.

Arranged within the tube 55 forming the main body of the expandable shaft 53 is a plurality of mechanical elements of the type described above to cause expansion or retraction of a corresponding plurality of annular arrangements of blocks 61. In the manner described hereinbelow, in the absence of As a force applied by the end actuators, the various springs 89 tend to carry the rods 93 and therefore the shoes 99, with respective mounts 69 to the position in figure 4, with the corresponding expandable blocks 61 positioned in the radially expanded position.

To control the retraction of blocks 61, in the illustrated example, shaft 53 has actuators at both ends, i.e., associated with both rods or ends 57, 59 to cause compression of springs 89 and thus the retraction of blocks 61 when a sleeve 51 is to be inserted into or removed from shaft 53. Thereafter, the actuator associated with rod 57 will be described initially in detail, the actuator associated with rod 59 being essentially symmetrical with the exception of some differences to be illustrated subsequently. It should be understood that alternatively a single end actuator could be used, especially for axes of limited axial length.

Associated with the rod 57 is a toroidal or annular piston 121 which slides in a chamber, either toroidal or annular, indicated with 123. Toroidal chamber 123 extending around the axis of the expandable axis 53 , can be filled with pressurized air through a plurality of passages 125 provided in rod 57. Toroidal or annular piston 121 is rigidly coupled to a second piston 127 by means of a connection formed by two connected and coaxial spacers 129 and 131. the other, produced therein, and within respective screws for reciprocal attachment and for securing to pistons 121 and 127, is a passageway that fluidly connects chamber 123 with chamber 133, into which piston 127 slides. With this arrangement, pressurized air fed through the ducts 125 pressurizes chamber 123 and chamber 133 by pushing pistons 121 and 127 which move rigidly from left to right (in the drawing).

Attached between each spacer 129 and the corresponding spacer 131, rigidly connected to one another, is a flange 135, subjected to which in turn are shoes 137 similar to shoes 99, sliding in rollers 139 housed in seats produced on the outer surface of a bushing. 140, rigidly connected to the rod 57. Sliding inside the bushing 140 is a rod or pin 141 with head 141A against which a compression spring 143 reacts, said spring being held between said head 141A and an inner annular shoulder or projection. 145 from bushing 140. Rod or pin 141 is rigidly connected to piston 127.

As a result of the described arrangement, a left-to-right movement (in the drawing) of the pistons 121, 127, caused by the intake of compressed air through the passages 125, causes a corresponding axial movement of the shaft or rod 141 and a corresponding compression of the spring 143. The movement of the pistons 121, 127 also causes an analogous movement of the shoes 137. Hinged to them are radially inner ends of the mullions 149 equivalent to the mullions 69 already described, the radially outer ends of which are subjected by means of spheres 151, to expandable blocks 153 equivalent to blocks 61.

In the arrangement illustrated in FIG. 3A, compression spring 143 is compressed in the same manner as springs 89 and pistons 121 and 127 are in their right-handed position with chambers 123 and 133 fully expanded. The shoes 137 are fully shifted to the right corresponding to a maximum inclination position (with respect to the radial position) of the mullions 149 and thus a fully retracted position of the expandable blocks 153. Like the blocks 61, these are held by coil springs. annularly wound about said blocks indicated with 155, which, like the springs 67 retain the blocks against the balls 71, 151 and against the distal ends of the risers 69,149 when said risers are in the maximum inclined position.

When pressure in chambers 123 and 133 is discharged, compression spring 143 returns to pistons 121 and 127 to the leftmost moved position.

As can be seen from Figure 3A, at the maximum spring compression position 143, the piston 127 is seated against a rod 92 coaxially housed within the pin 93 associated with the first group of expandable blocks 61. The rod 92 has a head that rests against the head 91 of the pin 93 into which it is housed, and an opposite end resting against the corresponding head of the rod 92 associated with the hollow pin 93 of the adjacent mechanism (i.e. associated with the subsequent annular group of blocks 61) and so on.

In this way with a single actuator composed of a pair of pistons 121,127 rigidly connected together and respective chambers 123 and 133 it is possible to compress the spring 143 and all springs 89 arranged in the various mechanisms positioned in succession within the tube 55. This causes the simultaneous retraction of all expandable blocks 61 and 153 with movement of the risers 149 and 69 to the inclined position shown in figure 3A.

In fact, within axis 53 about half of the expansion and retraction mechanisms of the blocks 61 are arranged in series to be operated by the actuator associated with the rod 57. In fact, associated with the opposite rod 59 the expandable rod or Axis 53 is an actuator, specular with one described above, for the purpose of which is to cause the blocks 153 associated with rod 59 to retract and the blocks 61 of a certain serial number of blocks 61 located at half of the nearest expandable shaft 53. of the rod 59.

In this manner, a balanced mechanism is obtained where the two actuators associated with the two ends of the shaft are used to cause retraction or expansion of respective expandable blocks 61 distributed in the two shaft halves. It should be understood that the block distribution may not be exactly symmetrical, and therefore the actuator associated with rod 57 can control a larger or smaller number of block series 61 with respect to those operated by the actuator associated with rod 59.

It will be understood from the above description that the block operating mechanism 61 allows the interchangeable sleeve 51 to be secured and released in a safe manner to allow easy removal and replacement while ensuring efficient and safe bonding even at high stresses. wherein the embossing rollers operate normally. The spring and upstream mechanism actually allows for radial force to be exerted on sleeve 51 and thus extremely high frictional force that prevents axial slippage and reciprocal rolling of sleeve 51 on expandable shaft 53. Symmetrical arrangement of mullions around shaft of the expandable shaft 53 and the arrangement of the axial compression springs prevents negative effects due to the fact that a radial tension is exerted on the sleeve, distributed along a generatrix representing the contact line of the embossing roller with the roller. corresponding pressure or with the opposite embossing roller with which it cooperates in the case of end-to-end embossing. It is understood that the drawing merely shows an example provided purely as a practical embodiment of the invention, which may vary in shapes and arrangements without, however, departing from the scope of the concept on which the invention is based.

Claims (22)

1. Embossing roller for processing a fabric material comprising a central shaft (53) and an interchangeable removable outer sleeve (51), said interchangeable sleeve having an essentially cylindrical outer surface provided with protuberances and / or cavities; characterized in that said shaft has radially expandable elements (61) for securing the glove. Roller according to Claim 1, characterized in that said radially expandable elements are controlled by mechanical elements. Roller according to claim 2, characterized in that said expandable elements comprise a plurality of expandable blocks (61,153) disposed on said axis. Roller according to Claim 3, characterized in that said expandable blocks are distributed according to annular arrangements aligned on said expandable axis. Roller according to Claim 3 or 4, characterized in that said expandable blocks are controlled by mullions (69; 149) within the axis. Roll according to claim 5, characterized in that said mullions are arranged in accordance with approximately radial arrangements. Roller according to Claim 5 or 6, characterized in that each of said mounts is subjected to an expansion and retraction mechanism. Roller according to Claim 7, characterized in that said expansion and retraction mechanism comprises the shoes (99; 137) sliding in an axial direction, in which said mullions are articulated, said sliding ones. shoes causing variation in the inclination of said mullions and consequent extension or retraction of the expandable blocks. Roller according to Claim 8, characterized in that said mechanism comprises a shoe for each mullion. Roller according to Claim 8 or 9, characterized in that said shoes are slidably guided in bushings (85; 140) coaxial to said axis (53). Roll according to claim 10, characterized in that for each annular distribution of said expandable blocks a distribution of corresponding mullions is provided, each of which is subjected to a respective shoe, sliding on a seat produced in a common bushing. Roller according to one or more of Claims 8 to 11, characterized in that it comprises elastic elements (89, 143) which tension said expandable blocks in an expanded position. Roller according to at least one of Claims 10 and 12, characterized in that said elastic elements comprise for each annular arrangement of expandable blocks a spring (89,143) housed in the respective bushing (85; 140). Roller according to claim 13, characterized in that a rod or pin (93; 141) is associated with each of said springs, the spring being held between the head (91; 141 A) of said rod. or pin and the corresponding bushing (85,140). Roller according to Claim 14, characterized in that said rods are arranged coaxially within said axis. Roller according to claim 14 or 15, characterized in that said rods or pins are aligned with each other and arranged resting against each other at least one actuator at one end of said roller being provided. to axially push said rods against the action of the respective springs, the compression of the springs caused by the sliding of said rods determining the retraction of the expandable blocks. Roll according to claim 16, characterized in that it comprises two actuators, each associated with a respective end of said axis, for each controlling a portion of the expandable blocks. Roller according to claim 16 or 17, characterized in that said actuator or actuators are piston-cylinder actuators. Roller according to claims 17 and 18, characterized in that said actuators are provided by an operating fluid not only one end of said shaft, an internal conduit (161) being supplied to supply the actuator associated with the actuator. the opposite end. Roller according to one or more of Claims 16 to 19, characterized in that said actuator or actuators each comprise a dual piston-cylinder system. Roller according to one or more of Claims 16 to 20, characterized in that the piston or pistons (121; 133) of each of said actuators are rigidly subjected to a series of shoes (137) in turn. subjected to the risers (149) to control a respective series of expandable end blocks (153). Embossing unit comprising at least one embossing roll produced as claimed in one or more of the preceding claims.