ES2561884T3 - Embossing on a flat metal starting piece (procedure and device) - Google Patents

Abstract

Embossing process of an artifact (11.11 ') on a wall of a can (10), in which (a) a flat sheet or part of the metal (s) is transported (vs) along of a transport bench (10) by several separate groups of rollers (20, 22, 24), each having an upper roller and a lower roller (20a, 20b;...); (b) a pair of rotary embossing rollers (30; 31a; 31b), arranged between two of the transport roller groups (22, 24), and driven by a servo transmission or motor (38), perform the embossing (32a, 32b) of the artifact (11.11 ') on the transported flat sheet or starting piece (s); (c) whereby the transport rollers on their surfaces, the embossing rollers on their surfaces, and the sheet or starting piece have the same speed (vs) during embossing of the artifact (11.11 ' ) in the starting piece or sheet, and a position of length (y11, y12) of the artifact in the sheet or starting piece is determined, adjusted or corrected by a speed and position control (40) of the servo transmission ( 38), which drives the pair of embossing rollers (30); (d) forming (26) a cylindrical shape of the base (s *) of the can wall (15).

Description

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DESCRIPTION

Embossing on a flat metal starting piece (procedure and device)

The invention relates to a method for embossing an artifact on a wall of a can. The metal can can be a three-piece can that has a wall that has a vertical weld line. This line

Welding 5 connects a cylindrical wall and this wall receives an upper end and a lower end joined by a seam thereto, to finish the can. Usually, these cans are aerosol cans, paint cans or containers for antiperspirants (Deos). These cans receive a nozzle on the top that when pressed releases the contents that are under internal pressure.

The invention further relates to an apparatus (claim 10) that allows embossing of this type.

10 in a three-piece can, preferably in the wall of the three-piece can, before being formed into a cylindrical element and, of course, before welding.

The cans are decorated using paint, printing or leaving the walls of the cans blank. Specifically the decorated walls are provided in an already printed or decorated version as starting pieces.

or flat sheets. They are stacked in a stack of decorated starting pieces that are released piece by

15 pieces, are placed on a bench and are processed by the transport rollers, to send them to the forming rollers that provide a cylindrical shape to each of the flat starting pieces. This cylindrical shape is open at both free vertical edges (both ends of the starting piece, converted into a cylinder) and will also be transported to a welding line, in which an axial weld is provided to close the cylinder and provide the wall of a three piece can.

20 A cold rolling process for printing patterns on a surface is publicly available from WO 2006/058424 (Novelis). This document discloses several examples of which the first two examples in those figures 2, 3 are microscopic characteristics of patterns that are provided by several pairs of consecutive rollers in that figure 1. Each pair of rollers adds additional additional pattern characteristics in a strip longitudinally transported from the sheet article (number 6 in that reference). Each roll

25 upper (number 2 in that reference) and each lower roller (number 4 in that reference) provide a gap 12 between them, which is slightly reduced in space, at least 5 µm, to provide a higher pressure to achieve the pattern on the surface of the strip of the longitudinally transported sheet article 6. Both rollers, each upper and lower roller, can be synchronized when using the second embodiment having characteristics of cooperating microscopic plateaus, number 10, either above only in

30 the first embodiment or above and below in the second embodiment, but still microscopic in nature. By having two microscopic patterns aligned (numbers 8 and 10 in Figure 3 of that reference) a synchronization of the two rollers occurs to align the pattern characteristics of one another, see page 7, lines 22 to 29. One macroscopic feature embossed is a third embodiment in that figure 4, which is explained on page 8, lines 23 to 31. The macroscopic embodiment has a recess and a projection (no.

35 ros 16 and 18 in Figure 4) which cooperate and provide a passage in space 12, which is very slightly thinner in the separation portion 14, in which the microscopic feature embossed is further printed on the transported sheet longitudinally. As can be seen in Figure 1, each pair of rollers has a distance from the other pair of rollers that adds additional patterns on the sheet to provide a more densely provided pattern at the end, when all free roller pairs have provided res patterns

40 pectives in pairs.

US 2002/0090578 (Schaefera) discloses the transfer of holographic images onto metal surfaces, especially beverage cans mentioned in paragraphs [0011] and [0012]. These holograms are "printed" on sheets or strips of aluminum foil or aluminum sheet. In that figure 2 a flat carrier 12 supplies the image, for example the hologram image, and transfers it to a printing roller 10 having on its opposite side of the carrier 12 a support roller 14. The transfer of this image from the printing roller in addition to the can shown in a large mandrel in Figure 4 uses the printing roller 14, and this printing roller presses against the surface of the can 30 when the mandrel and the printing roller are rotating, see paragraph [0050] with respect to the mandrel and paragraph [0047] with respect to the transfer from the flat carrier to the support roller or to the printing roller 10. The pattern is therefore not transferred to a sheet

50 flat metal which is after embossing is transferred to its canned form which is cylindrical.

It is an object of the present invention to provide a decoration added to the can which receives an additional conformation in the can wall and, which eventually supports or enhances an impression. This could have a visual appearance or appearance and receives a three-dimensional shape and improves the attitude and appearance of a printed logo, a printed sign (Schriftzug) or an image that receives an additional three-dimensional conformation. This also allows the

55 Braille writing and allows the use of writing on the tin wall to blind people.

The invention achieves this through the use of embossing that is provided before shaping. Embossing is not done on the closed cylinder, but is done before the preparation of

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this sheet / piece of flat white to a cylindrical shape, so that it is positioned on the manufacturing line after (behind, downstream) of the placement of the starting piece or flat sheet, printed or unprinted before forming, on the transport bench and before (upstream) of the forming rollers that are behind in the transport bench. By placing the embossing rotary rollers here the artifact is provided, 5 which represents any type of in-depth shaping, such as a logo, writing, letters, image or any other form of decoration, will reduce the harmful effects on a line of manufacturing. Additional embossing rollers can be placed here without altering the entire transport and manufacturing line. Amendments or new configurations to this manufacturing line are minimized. Specifically, the embossing rollers are placed behind the transport rollers, of which there are several pairs arranged as groups (each group has an upper and a lower transport roller). After the transport rollers grip the flat starting piece, this can be measured in relation to its position on the bench by at least one encoder in at least one of the rollers and the sliding is minimized, even when there is no slip at all . It has a certain position and distance that is reduced towards the forming rollers. Before these forming rollers, the embossing rollers receive the transported flat starting piece (tam

Also known as "sheet", in what follows in the present specification it will be referred to as a starting piece, although the starting piece also has a decorated surface such as by printing). This starting piece has a certain relative position towards a "central embossing point" between an upper and a lower embossing roller, which is called "embossing position / line".

The leading edge of the transported starting piece decreases its distance from this stamping position

20 in relief that can be understood as a horizontal line, parallel to the two axes of the upper and lower embossing printing rollers. At the time of finding this transported flat starting piece, the embossing rollers have the same speed, at least substantially the same speed as the transported flat starting piece, to prevent slippage (claim 1). Therefore, the transport rollers, embossing rollers and the sheet / starting piece have the same speed on the surface of the

25 starting piece. This happens when the artifact is embossed on the starting piece (claim 1).

The surface speed refers to the circumferential speed of the transport rollers and embossing rollers. Both touch the surface of the starting piece. In this way, this surface has the same speed (longitudinal) as the circumferential speed of the mentioned rollers. Since the surface is not separated from the starting piece, the entire starting part has the surface speed.

30 Generally, embossing rollers will be made of metal, both the upper and lower rollers. The upper roller may have a protruding part and the lower roller may have a depression, in which the protruding portion is properly adjusted during rotation at any time when the upper projection and the lower depression meet. This is generally done by a gear transmission timing that keeps the relative positions of the two embossing rollers fixed.

35 Rotary embossing rollers that engage with each other are driven by a "servo" (transmission or motor) that has control. This control provides a control of the position of the embossing rollers to adapt to the position of the sheet of transported starting piece.

To understand the effect of this position control, the protruding part and the depression of the embossing rollers have to fit or be registered in a certain position on the trans blank

40 cover When there is already a printed portion that must be impacted by the depression and the protruding part, the axial position and a distance from the leading edge are determined. Both embossing portions of the embossing rollers have to conform to such an "artifact field" that is already printed on the sheet / starting piece. This is called a position of the artifact, field or a printed artifact, to which the embossed artifact that is provided to the starting piece has to be adjusted.

45 The embossed artifact will have a certain distance from the leading edge of the transported starting piece, and such that the printed artifact also has this certain distance from the leading edge.

With one and the same embossing roller, the axial position (viewed horizontally) will not change, and in this way the control will record the circumferential position of the embossing portions of both rollers and the artifact field (or position of the artifact) in the flat starting piece. After the embossing rollers with the rear edge of the starting piece have left 50, this starting piece is still flat and will then be transported either by an additional pair of transport rollers (upper and lower rollers) or either by configuration rollers, which can also be functionally treated as transport rollers, which have the additional function of preparing the cylindrical conformation of the sheet still flat and transported. Accordingly, the control causes the embossing rollers to have the same speed as the starting piece transported on the surface of the starting piece when embossing is performed and may be somewhat earlier, when it is already being gripped. the leading edge of the sheet transported with embossing rollers. There may be an additional circumferential space corresponding to a lateral space from the welding edge (the leading edge) of the sheet until the stamping field is reached

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in relief, in which the embossing portions of both embossing rollers are acting on the sheet.

This position length of the artifact in the sheet is determined by means of calculation and can be adjusted by controlling the circumferential position of the embossing portions of the rollers. Your rotations also

They can also be corrected, when a control is designed as a forward feed control by providing the rollers with a speed approximately identical to the transport speed of the starting piece and additionally providing a position control that corrects the remaining differences. An inverter unit will provide power to the engine and will affect the control to record both embossing portions so that they correspond to the given position of the embossed stamping field on the starting piece.

10 The best option to provide this control is an established value of a sensor that detects the leading edge of the transported sheet. This leading edge detector will be at a certain distance from the embossing line (the line between the two embossing rollers) and the calculation can be made with respect to the time required at a given part speed, until the leading edge reaches the embossing line or an embossing position (claim 3).

15 Operated in the best way, the embossing rollers already have a speed that is a circumferential speed in the circumference that is equal to the speed of the transported sheet, and the distance of the embossing portions (male part and female part) are in circumferential terms the same from the embossing line as from the leading edge of the starting piece (measured by the sensor probe) of the same objective, the embossing line between the rollers. The transport of the starting piece and the

20 rotation of the rollers, therefore, are already synchronous and will reach the best record. The further the embossing field is separated from the leading edge, the farther the male and female embossing parts have to be from the previous position that was intended to emboss on the leading edge of the piece. of departure. Generally, the leading edge is free and no embossing or embossing field will be additionally upstream of the transported sheet and

25 therefore, the registration of the embossing portions of the rollers are also separated from the "meeting position for the first time".

The control provides a correction, when this is not adequate at the time of detection of the leading edge of the starting piece. By having an encoder in the servo transmission, this encoder allows the exact measurement of the position of the embossing portions (male and female) of the rollers, such that

All control variables are measurable and can be adjusted in a system that offers ease of correction of each transported sheet that is to be embossed in its own embossing field.

It is assumed that each starting piece meets its leading edge separated from the previous starting piece to have a certain proper circumferential position properly adjusted, therefore, each leading edge triggers a new control action to the servo motor that drives the rollers Embossing Every

35 foil will be provided along with an accurate embossing record and field of artifact eventually printed.

As mentioned, the forming takes place after embossing the feature of the artifact on the transported starting piece (claims 1, 10).

It is best to have rubber rollers that are above and metal rollers that are below

40 of the transported sheet, to minimize slippage. These rollers are kept synchronous by axially spaced geared wheels outside the transport bench. The best option is to provide the leading edge sensor between two pairs of separate rollers (each upper and lower roller) to have a fixed position of the transported flat sheet relative to the circumference of the roller, before the detection of its leading edge ( claim 2).

45 The edge control signal or the reference signal having an leading edge will be sent to the control section that can eventually adjust or correct the speed of the servo motor or transmission to momentarily accelerate or slow the embossing rollers to allow the position to register to the position of the target, which is the field of the printed artifact. Even so, the speed has to be the same again when the leading edge of the flat starting piece reaches the position / embossing line between

50 the two embossing rollers.

The leading edge of the sensor signal can be used to calculate the time interval that is still available before the leading edge reaches this embossing position (claim 3).

Since the transport rollers, at least one of them, could also have an encoder, the speed (and position) of the starting piece is known by the control system and the activation of the sensor or the detection of the leading edge. of the transported sheet will allow, using the same speed, calculate the time interval

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which is still available for the control to adopt the position of the embossing parts (male and female) on the embossing rollers. The edge detector could have a detection nose that is directed upwards and can operate with magnetic field influence or it could operate optically.

Match the target position (claim 4), thereby adjusting the circumferential position of the

5 features of embossing takes place during rotation. The embossing rollers will not stop and will not accelerate in each transported starting piece, on the contrary the embossing rollers will be driven with an assumed speed that is calculated, or generally assumed or measured from the speed of the transport rollers, which already have a speed and minimize control actions to the embossing rollers. However, there may be necessary positional adjustments since each

The starting piece has an instability with respect to the instant of time in which the nose of the leading edge sends the reference signal to the control.

Control actions are used to stabilize the system to avoid possible stamping failures. Each embossing that is slightly offset from the embossing field will destroy this sheet for later use as a cylindrical wall or can and, therefore, these stamping faults have to be reduced.

15 to the minimum.

A minimum cut is a requirement, supplemented with the high speed that is required to minimize process delays. Therefore, embossing rollers have to rotate at high speed as well as the transport speed of the starting pieces and still of each starting piece (sheet) that has to be embossed at a certain time and position , which are given by the position of the artifact that is already there over

The starting piece (claim 5).

The tool that is capable of producing this high speed and minimized cuts and improves the design of the artifact has this pair of embossing rollers mentioned (claim 10, feature c). The pair of embossing rollers is driven by a motor / transmission servo and the embossing roller is placed behind either the last transport roller or between the last and the penultimate group of transport rollers25 (each with an upper roller and a lower roller) to act on a flat starting piece or still flat sheet. The pair of embossing rollers is rotatable and each one, the upper and the lower one, has an embossing function (one has a male characteristic, the other a female characteristic) to register in the position, in which both rollers become as close to each other and have a distance that corresponds to the thickness of the sheet that is transported through this embossing line or stamping position

30 in relief (claim 3).

To make this registration safe and secure, the upper and lower embossing roller are mechanically coupled, preferably by means of sprockets axially provided outside at one end of each axis thereof (claim 15).

Before embossing rollers, there are one or more groups of transport rollers, the upper one having

35 a rubber circumference and the lower one having a metal circumference. They are driven with a transport speed that is synchronous with the speed (circumferential speed) of the embossing rollers, the servo transmission still controls the embossing rollers regardless of the speed of the rollers. transport. All transport rollers can thus be coupled to each other by means of a belt drive or gear wheels. Still, the stamping rollers

The relief features are decoupled and electrically synchronized with the same speed by the servo transmission that provides this same speed per control.

The "same speed" could be altered by the control that is activated by the reference signal indicative of the leading edge of a through sheet and provided by a sheet detector. This feed rate of the starting piece is provided to the starting pieces by the transport rollers. Speed controller

45 provides the same speed by means of the servo transmission to the embossing rollers and, therefore, the coupling of the speed is performed electronically and not by transmission by belt or sprockets.

Both embossing rollers are permanently mechanically synchronized by gears (claim 15). They never lose their synchronization with respect to each other, to adopt cooperates

50 tion of the complementary features of embossing.

A metal can has a cylindrical body that has a height that is greater than a diameter thereof and is produced by the embossing process (claim 1) as a product that is obtained directly. It has the embossing artifact on the wall and this before having a weld or seam in the axial direction that connects the axially extending free edges of the body wall in a cylindrical shape. This could be, when it has a top end with seam and a bottom end with seam, it could be a

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aerosol can, having a weld or seam that extends axially. This joins the free edges of the cylindrically preformed wall.

Usually, these cans are called three-piece cans and protection must be conferred on the wall before welding, after welding and when it is implemented in a finished metal can, which has a cylindrical wall and a cover. upper and a lower end with seam by a double seam to the cylindrical wall.

The examples will improve the understanding of the invention as claimed. The following examples are true examples that are not intended to limit the invention and are not intended to disclose "essential features that are lacking in the claims", but rather the examples are provided to improve the understanding of the claimed invention and serve for disclosure to a skilled in the art.

Figure 1 is a side view on a bench and a stack S of many flat starting pieces s, two groups of transport rollers 20, 22 are present and a pair of embossing rollers 30 shown below are shown. It is not shown, but because of the indicated position it is a place of the forming rollers 26 that are rotating the flat shape of the starting pieces s after having been provided with the embossing feature in cylindrical preforms, subsequently welded

15 each other at their free edges.

Figure 2 is a more schematic representation of the detection of the position of the leading edge s1 of the transported sheet s having a distance and from the embossing position 33 between the embossing rollers 30.

Figure 3 shows the object that is provided as an aerosol can (left) and as a piece of torque

20 flat unrolled tida, (right) in which four positions of embossing artifacts are shown. Not every one of these four has to be present, one of them could be there and is shown in the left portion of the image as a "print" logo that has both writing and logo. Without writing or letters, the initial logo "1" could also be present as a unique artifact that needs improvement by a three-dimensional conformation. In the flat starting piece (figure 3, to the

25 right) The complete embossing area indicates that it can be used throughout the entire piece. A certain portion such as an edge portion of the flange is surrounding the entire rectangular field in which the reliefs could be placed. Four of these certain fields are shown, one of which is 11a, which receives the three-dimensional embossing 11 at a distance and 11 from the leading edge s1 of the starting piece s. The length of the starting piece d substantially determines

30 the diameter d of the finished can 15. The height h of the starting piece substantially determines the height h of the can (as shown on the left).

Figure 4 is a control section 40 that is used in Figure 1 to control the servo motor 38 (servo transmission).

Figure 5 is a schematic representation of the approximation of a starting piece s to the line of

35 embossing 33 and schematically the upper (or lower) embossing roller 31a, which incorporates the female embossing feature 32a, to impact the embossing field 11a at the same speed vs and in the line Embossing 33.

Figure 1 transports the planar parts s from left to right. There is a feeder or hopper 18 that holds a stack S of many stacked sheets s, which are lowered by a lifting device 18a at the bank level

40 10. In the side view, a starting piece s is placed by a mechanically controlled rotation device 18b which further lowers the starting part s with the lifting device 18a and places it on the bench 10. It is synchronized to the left joining it to a bar 18c with the direction of the upper side and part. The starting piece "s" has a leading edge s1.

After this starting piece has been positioned on the bench 10, it will be advanced towards the first pair of

45 transport rollers 20. They rotate in opposite directions (upper and lower) and grab the leading edge s1 and the entire flat starting piece. It will be sent at the transport speed, applied to the starting piece s by the first transport rollers 20. This speed is above 150 m / min and up to 190 m / min. Next, the transported part s is also held by the second transport rollers 22, which have an upper roller as well as a lower one.

50 To synchronize the speed of the rollers and the speed vs of the starting piece s, there is almost no slippage and this is supported by an upper rubber roller and a lower metal roller. They grip each sheet s transported (sent for feeding) and the speed on the outer surface of the metal roller is the same as the speed of the sheet transported (metal starting piece). Tinplate sheets (the starting pieces) can have a thickness of 0.18 mm to 0.20 mm. Substantial tin plate plates have been examined

Thicker mind, up to 0.5 mm and 0.7 mm, even at reduced speed vs transport.

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To ensure a measurement of this speed, an optical detection is not required, only a detection of the rotation of a lower transport roller is measured by means of an encoder 17. This encoder is directly coupled to the axis of the lower transport roller 22a or it is coupled to it by means of a transmission belt 16 that is not shown separately in detail, only as a schematic linkage or connection.

All transport rollers 20, 22, 24 are coupled by gears or belts or toothed belts to provide a laterally extending transport unit, which has the same speed on all transport rollers along the transport bench 10.

When the first sheet s transported is gripped by both transport rollers 20, 22, the next sheet is lowered from the stack S and is also placed in the initial position of the bench 10, as shown in the drawing. The synchronization of the sensor 18d and the mechanical rotating motor provides an up and down movement of the collection device 18a '(shown in dashed lines) and picks up the lower sheet s of the stack S and is shown in continuous lines 18a when it is in the lowest position at the top of the bench 10. When the starting piece has left this place and is sent to the initial transport rollers 20, the pickup device 18a will be lifted again and will pick up the next lower part of the S stack.

Further on, towards the embossing rollers 30 having an upper roller 31a and a lower roller 31b, they are provided with a sensor 50 shown in more detail in Figure 2. This can also be placed directly behind the group of initial rollers 20. Said distance may be less than 10 cm, 5 cm or 2.5 cm and between rollers 20, 22.

This sensor 50 touches with its nose portion 51 the leading edge s1 of the incoming sheet s having the velocity vs. This detection signal when the leading edge 55a as shown in the time chart is at the beginning of the control cycle. It is sent to control system 40 as signal 55. The rising edge (which could also be a falling edge) is called the leading edge 55a. A duration of this pulse detected by the nose 51 is the length of the sheet divided by the speed of the sheet.

The sensor 50 provides this signal 55 to the control system 40 which controls a servo transmission (AC motor) 38 that drives either the upper embossing roller 31a or lower 31b. Both embossing rollers are mechanically connected by a linkage that can be a cogwheel linkage, which allows continuous mechanical synchronization of the upper and lower roller and a fixed coordination of the male boss 32b and the female notch 32a provided as features for embossing at a certain place on the circumference of both upper and lower embossing rolls 31a, 31b, see Figure 1 for this detail.

After the initial edge s1 (the leading edge) of the starting piece s has passed through the nose 51 of the sensor 50, which can be operated magnetically, there is a remaining distance Y1 from the embossing position 33. This position is the minimum distance between the upper and lower embossing rollers and the place where embossing should take place, when the printed artifact or the target position, when no print is present on the sheet s, has This position of the bank 10 has been reached. The portion of this path is already shown in Figure 1, after in Figure 2 it has sent the leading edge 55a at the instant of time t1 to the control system 40 as signal 55.

Taking the velocity vs as substantially constant during the travel of the starting piece s from the position shown in Figure 2 to the position reached slightly after that shown in Figure 1, when the leading edge s1 reaches the stamping point in relief 33, and the distance Y1 is fixed, the time T1 can be calculated. Moving 50 to the left increases the time T1 allowed for the control register of embossing rollers 30.

The calculation is performed by the control system 40, which determines the angular position of both embossing features 32a, 32b from the embossing position 33. The angle α2, as shown in Figure 5, multiplied along the radius r31 of the upper roller 31a (and of course, the lower roller 31b) gives the distance along the circumference that the embossing feature 32a (and the corresponding embossing feature 32b for the lower roller 31b ) has from the point, position or embossing line, 33. This circumferential distance is α · r31 / 360 ° = x2

This is the calculation for the leading edge that impacts the embossing point or line 33.

In general, the embossing field 11a shown in Fig. 5 is not provided on the leading edge s1 but the distance y11 is delayed or separated backwards. This field 11a is the place where the embossing 32a / 32b has to impact against a transported sheet s with the same speed at which the starting piece s moves to provide a clean three-dimensional conformation in this field 11a. Control system 40 is provided and determines such exact preconfiguration in the flat device s that travels at speed vs.

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In a first approximation, the velocity v31 in the circumference of the upper roller 31a and the velocity vs are the same. The distance of both 11a and 32a from the embossing line 33 is also the same, when the control system 40 has corrected or adjusted the speed and position of the upper (and lower) embossing rollers 31a, 31b .

5 Embossing rollers 30 have a larger diameter than transport rollers. Experiments have shown that larger rollers that are designed below 75 mm in diameter are a good option.

The larger y2 in Figure 5, the more separated (in terms of circumference) the notch 32a from line 33 has to be arranged, assuming the same velocity v31 and vs. When this distance is not the same in 10 angular terms and in linear terms, the control needs to either briefly accelerate the upper and lower roller 31a, 31b, or delay them for a moment, to adjust the distance and in addition to this provide control of distance as mentioned by making y2 the same as x2. This is the ideal condition that allows both devices to approach the embossing line 33 at the same speed. When the embossing rollers 31a and 31b grip the leading edge s1, the embossing groove 32a (and,

15 correspondingly, the embossing projection 32b, which is not shown in Figure 5, but shown in Figure 1) has a distance from this embossing line 33 corresponding to y11, but on the circumferential surface outside of embossing rollers 30.

The embossing action - after grabbing the starting piece s - is delayed as much as the distance y11 reaches from the leading edge s1 and after embossing, the starting piece moves

20 additionally through a groove between the two embossing rollers to be sent to another group of transport rollers 24 (not shown in Figure 1) and other forming rollers 26 that are further downstream, which are not shown in figure 1, but shown in position.

The servo drive 38 is driving the upper embossing roller 31a of Fig. 1. The embossing rollers are linked or connected by a sprocket system 39, shown

25 schematically only.

The buttons 48 provide basic functions in the control section 40. A display 49 shows the machine and system data on a screen, to visualize the operation and function of the control system 40 of the embossing rollers.

To make time T1 available for registration (or synchronization) action, as long as it is possible

30 ble, the leading edge detector 50 should be placed as close as possible behind the first group of transport rollers 20. In this way, the starting part has already been registered with the rotation speed of the transport rollers, and A rotation encoder can provide reliable position data of the advance of each of the starting pieces s. The rotation encoder is coupled to any one of its axes or to a belt drive that connects the axes of those transport rollers.

35 The control system is shown in more detail in Figure 4.

Two PI controllers are connected in series. One is position control 41 and the other is speed control. The speed control 42 controls a thyristor, IGBT, or transistor inverter 43 that drives an AC servo motor 38, linked either by gears or by direct transmission to the upper roller 31a.

At an initial or established value y2 is provided to the PI 41 controller which is the position control. The position controller 40 could also be a proportional controller.

The setting value is provided as a value of y. and is y2 as shown in Figure 5 as the distance of the embossing field 11a, to which the embossed embossing artifact has to be placed, from the embossing line 33. The control of the servo transmission 38 makes that x2 has the same value. The control also makes the speed of the outer surface of the roller 31a and the speed of the starting part s the same.

45 The leading edge s1 has a distance y1 and the distance y11 of the embossing field 11a from the leading edge s1 is added thereto, both composing the distance y2 which is the adjustment value for the control of position 41 in the system control 40.

Since the speed will naturally be given by the position controller 41, when it is a controller that has an integral component, such as the output of the controller 41, it can be assumed that this velocity vs will be

50 the same as v31, and therefore a pilot signal (forward control of the power supply) can be implemented, supplying the position control output with an added value of vs. Therefore, the control component or the compensation component from the controller 41 needs to be small and can be reduced to zero, when the relative position of the roller and the sheet is correct and the speed is the same for the roller 31a and the starting piece s.

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Other controllers can be used, the PI controllers are shown for ease of reference and an example of providing error-free control for speed (used for zero slip production when touching the starting part s with the embossing roller 31a / 31b) and to reduce any deviation from the embossing field 11a as a zero position error of a moving starting piece. The controller 42 may be of the PID type, the controller 41 may be of the P type.

The result is shown in Figure 3. Figure 3 has an unrolled wall of the three-piece can 15, which has the feature of embossing 11 arranged on the wall. This feature of embossing is mainly an I logo with an oval inclined shape and a writing that continues in the axial direction is added thereto. In this example, embossing has to be a flat notch like the additional artifact on the can, which can be read by touching a writing similar to the Braille writing. Blind people can read the outer surface of the can.

When printing on the flat starting piece s has been provided before as shown on the right side of Figure 3, the printed area may contain the same shape in the printed color, as they will receive embossing. Therefore, embossing has to be registered completely and precisely with the printed artifact. This is the target position when a printed artifact is already provided in a flat sheet printed decoration. However, it should be mentioned that color decoration is not a requirement to provide precise positioning of the embossed artifact. This can also be provided on a metal surface, not decorated by writing or can be provided on a surface already printed in color, which does not have a specific writing on it, on which the embossing should be placed.

The distance y11 as seen in figure 3 is as shown and explained in figure 5. This embossing field 11a is initially a print-logo-central writing on the left end of field 12. This field 12 marks the places where the tool and with it the procedure that is disclosed, can provide embossing features. It can be separated up and down and it can be separated back and forth, leaving a small edge edge, completing the complete starting piece s which is a flat sheet or can be tinplate.

As seen in Figure 3, other distances y12 can be provided and other axial positions can also be provided, when viewed along the height h of the can on the left side of Figure 3. To do this, the rollers 31a, 31b have to be replaced with other rollers that carry their embossing function 32a, 32b in a different axial position (along the width of the bench 10). By control, the position from left to right in Figure 3 can be corrected, changed, adapted or modified according to customer orders. This is done by changing the adjustment value of the control and changing the value of y2 in Figure 5 giving an adjustment value and the control system 40.

Another field 11a "for embossing is provided at the right end of the embossing area 12 and is open for placement of a feature 11" embossing. The distance y11 is substantially greater to reach the embossing field 11a.

The other modified axial embossing fields 11a 'and 11a "' can be seen in Figure 3, the embossing field 11a 'has the distance y12.

After the formation of the flat starting piece s embossed with forming rollers 26, the cylindrical wall s * is used which is used to constitute the three-piece can, as shown in Figure 3, left part. The diameter d is substantially the length of the starting piece and the height h of the can 15 is substantially the width of the starting piece s.

A bulging outer upper end (cover) is sewn together to the upper edge of the cylindrical wall and a lower end (closure piece) is sewn together to the lower edge of the cylindrical wall s *. A pressure operated valve can be placed in a central opening of the bulging upper cover.

Claims (11)

image 1 1. Embossing procedure of an artifact (11.11 ') on a wall of a can (10), in which (a) a flat sheet or starting piece of the metal (s) is transported (vs) along a trans bank bearing (10) by several separate groups of rollers (20, 22, 24), each having an upper roller and 5 a lower roller (20a, 20b;...); (b) a pair of rotary embossing rollers (30; 31a; 31b), arranged between two of the transport roller groups (22, 24), and driven by a servo transmission or motor (38), perform the embossing (32a, 32b) of the artifact (11.11 ') on the transported flat sheet or starting piece (s); 10 (c) with which the transport rollers on their surfaces, the embossing rollers on their surfaces, and the sheet or starting piece have the same speed (vs) during embossing of the artifact (11,11 ') in the starting piece or sheet, and a position of length (y11, y12) of the artifact in the sheet or starting piece is determined, adjusted or corrected by a speed and position control (40) of the servo transmission (38), which drives the pair of embossing rollers  15 (30); (d) forming (26) a cylindrical shape of the base (s *) of the can wall (15). 2. The method of claim 1, wherein a leading edge detector (50, 51), positioned along a path of travel of the sheet or starting piece (s), provides speed control and position (40) with a reference signal (55, 55a), which represents a step of the leading edge (s1) and an in 20 remaining time interval (T1), until a line of embossing or position (33) between the embossing rollers (30) is reached by the leading edge (s1) of the sheet / starting piece.

3.

The method of claim 2, wherein the time interval (T1) is calculated using a distance (Y1) between a leading edge detecting nose (51) and the embossing position (33).

Four.

Method of one of the preceding claims, wherein the speed and position control (40)

25 adjusts a circumferential position (x2) of a pair of embossing features (32a, 32b) on the pair of embossing rollers (30) during rotation, to match a target position (11a, 11a ') on the sheet / starting piece (s), in which in (y2; y11, y12) embossing is carried out and the artifact (11.11') is embossed. 5. Method of one of the preceding claims, the sheet or starting piece having a surface 30 printed and a target position, in which a printed artifact (11a, 11a ') is provided, which must be received by the embossed artifact (11.11'), the can (10) being preferably a can of three pieces (10) of spray, paint or other product. 6. The method of claim 4, the target position being the embossing field at a distance (y11) from the leading edge (s1). The method of claim 4, the control system (40) having at least one PI controller (41, 42) as the speed and position control.

8.

Method of one of the preceding claims, the servo transmission (38) being an AC motor.

9.

Method of one of the preceding claims, the upper and lower embossing rollers (31a, 31b) being rotatably linked by a gearwheel coupling (39).

40 10. Apparatus for embossing an artifact (11.11 ') on a wall of a three-piece can (15), the apparatus comprising

(to)

several groups of transport rollers (20, 22, 24), each having an upper and a lower roller;

(b)

a pair rotary embossing rollers (30), which have stamping characteristics in

Relief (32a, 32b) in a certain position on its outer surface, and being mechanically coupled to a servo motor or transmission (38);

(C)

the pair of embossing rollers (30), and the servo (38) are placed between the last group of transport rollers (24) and the previous one to the last (22), to act on the flat starting pieces

or sheets (s);

(d)

a controller (40) for controlling the servo (38) and receiving a reference signal (55, 55a) indicative of a leading edge (s1), each of the starting pieces / sheets passing through a reed detector (50) at a feed rate (vs) applied to the starting piece / sheet by the transport rollers (20, 22, 24)

10 image2 The apparatus of claim 10, which has a speed coupling when the rotation speed of the transport rollers (20, 22, 24) by a mechanical linkage, such as sprockets, belt, timing belt, and a coupling The speed corresponding to the embossing rollers (30) is done by means of the control (40) and is applied by the servo transmission or motor (38). 12. Apparatus of claim 11, wherein a speed of embossing rollers is allowed 10 (30) or is even forced to change compared to the transport rollers (20, 22, 24), to adjust the position deviations (y2, x2), preferably comprising the controller (40; 41, 42) at least a speed controller (41). 13. An apparatus of one of the preceding claims 10 to 12, a diameter of each embossing roller (30) being greater than a diameter of each transport roller (20, 22, 24). 14. An apparatus of claim 10, a distance of the sheet detector (50, 51) being less than 10 cm from the first group of transport rollers (20), preferably less than 5 cm or less than about 2.5 cm . 15. Apparatus of claim 10, the pair of embossing rollers (30) being linked or connected by a sprocket system (39). eleven