EP1600291A2 - Embossing machine - Google Patents

Abstract

The machine (11) has a first cylinder (13) driven by an electric drive (30) and essentially coaxial with a first cylinder and a controller for the drive that processes synchronous signals related to the revolution rate of a second cylinder (14) and data associated with desired deviations from the synchronous revolution rate and converts them into control signals for preferably periodic revolution rate variations of the first cylinder during a revolution of the first cylinder.

Description

Field of Application and Prior Art The invention relates to an embossing machine for transferring surface portions from a carrier web, such as a film, to a substrate, such as a sheet or traveling web of paper or other materials.

With such embossing machines flat structures, such as Holograms, areas of metallized foils or metal layers, impressed on a substrate, usually in heat-sealing process. For this purpose, the corresponding surface section on the carrier film applied and with the aid of a heat-sealing layer, the surface portion detached from the film and impressed on the substrate.

Such an embossing machine is shown in DE 196 25 064 C2 and described in detail. It also describes a mechanical non-uniformity gearbox, that between the tool and the impression cylinder is switched on and adjustable periodic changes the peripheral speed of one of the cylinders during each one turn allows. For the reasons described there It can thus be achieved that at the time at which Tool on the tool cylinder located on the carrier web Print image on the substrate transmits exactly the same peripheral speed Both cylinders are present, although there are slight differences in can give the effective diameters of the two cylinders. So will So for example when too small tool cylinder this approaching accelerated at the printing time and then delayed again, that at the next circulation the register validity is maintained again is.

Task and solution

The object of the invention is to provide an embossing machine, this Function with less mechanical effort allows and In addition, further possibilities and improved adjustability opens.

This object is achieved by claim 1.

The invention thus uses a mechanical of the second cylinder, usually the impression cylinder, decoupled electric drive for the first cylinder, which is usually the tool cylinder. The impression cylinder also has the task of bowing machines to take the bow and to transport through the nip and is also to a Series of follower units connected, so here's an accurate Positioning and tactness is necessary, what one to the rest Machine fixed bearing conditioned.

The tool cylinder, however, can in its axial distance from the impression cylinder be adjustable and movable in its effective Diameter passing through the surface of the tools attached to it is defined, depends on their thickness. Furthermore, the tool cylinder heated during heat seal transfer, so that thermal Extensions arise which are accurate to within a hundredth of a millimeter Adjustment of the pressure nip certainly play a role. therefore previously had the scope of the impression cylinder laborious by so-called lifts, i. not participating in the actual printing process Bow of different thickness, to be adjusted.

Regarding the function of the nonuniformity drive and the details the embossing machine is referred to the aforementioned DE 196 25 064 C2 also referred to for the purpose of disclosure. The electric drive according to the invention, the mechanical completely from the synchronous drive the rest of the machine is decoupled for example, by the impression cylinder or its drive corresponding encoders, for example frequency generators or the like, are arranged. In an electronic control unit, for example a computer, the data on the speed of the two cylinders compared with each other and the desired periodic deviations via a stored program, manually or on other Ways was entered, changed. Thus, a much greater flexibility the speed changes possible. It could be for example at several, each separated by an "empty route" Tools on the circumference of the tool cylinder, the speeds accordingly often per revolution to the synchronizing peripheral speed adjusted and in between for the appropriate delay be ensured so that the resulting speed exactly with the Counterpressure cylinder matches what is required for the registration accuracy is. Surprisingly, this is despite abandoning mechanical Coupling possible.

Preferably, a three-phase motor is used as the electric drive, the speed changes via a controllable frequency converter certainly.

At the high working speeds and accordingly high Speeds are the accelerations and decelerations that the electric drive transfers to the tool cylinder, very large. These moments usually also transfer to the storage of the corresponding driven cylinder, causing vibrations and considerable Impact loads on the adjusting members for the tool cylinder leads. According to a further feature of the invention is the electric drive an electric motor with a stator and a rotor, wherein the stator to stored another machine part than the first cylinder. If the first cylinder is mounted on an adjustable machine part, for example a rocker, then the stator, for example, over a support arm on a machine-fixed part, ie on the machine frame, be supported so that he can increase his reaction to the Acceleration and deceleration moments directly on the machine frame and does not transfer to the swingarm. This is also the Adjustment drive for the rocker, for example, a linear electric motor or a hydraulic cylinder, from these vibrations or shock loads kept free.

Preferably, the support arm can be vertical to the connection of the cylinder axis run with the axis of the adjustment rocker and over a Sliding seat to be connected to the machine frame. On such a Sliding seat can be omitted if the support arm in the direction this connecting line between the axes runs and the support for example, on an extension of the swingarm axis he follows. In this case, the support arm would run parallel to the rocker, however, support the stator independently of the rocker.

It can be seen that by the invention the adjustability and the Options for adaptation are greatly improved. It is through not only possible to compensate for minor differences in diameter, but actively intervene in the minting process. It can not only larger diameter differences are compensated, but it can also be achieved effects that previously not possible appeared, for example also the synchronization between tool cylinder, Impression cylinder and the two material webs involved be acted, for example, on the edges of a tool due to circumferential velocity deviations to an active "demolition" produce.

Preferably, therefore, an embossing machine for transmitting holograms etc. created by a carrier sheet on a web or a sheet, the one tool cylinder and a counter-pressure cylinder has, between which the pressure gap over a tool cylinder overlapping swingarm is adjustable. An electric drive of the tool cylinder makes it possible, by means of a controllable frequency converter fed three-phase motor the tool cylinder in deviation to move from the synchronous speed of the impression cylinder. Reaction forces caused by the acceleration and deceleration of the electric drive be directly from the stator of the electric drive via a Support arm derived on the machine frame.

The foregoing and other features are excluded from the claims also from the description and the drawings, wherein the individual features in each case alone or in the form of several sub-combinations in one embodiment of the invention and be realized in other areas and advantageous as well as for themselves represent protectable versions for which claims protection here becomes. The subdivision of the application into individual sections as well as subheadings restricts the made among these Statements not in their generality.

Brief description of the drawings

Fig. 1

einen schematischen Querschnitt durch die zusammenwirkenden Zylinder einer Prägemaschine und ihrer Lagerung ohne alle übrigen Aggregate, in Fig. 2 in Richtung des Pfeiles I gesehen,

Fig. 2

eine Seitenansicht des in Fig. 1 dargestellten Aggregats und

Fig. 3

ein Funktionsschema des Antriebs.

An embodiment of the invention is illustrated in the drawing and will be explained in more detail below. Show it.

Fig. 1

a schematic cross section through the cooperating cylinder of an embossing machine and its storage without all other aggregates, seen in Fig. 2 in the direction of arrow I,

Fig. 2

a side view of the unit shown in Fig. 1 and

Fig. 3

a functional diagram of the drive.

Detailed description of an embodiment

FIGS. 1 and 2 show, schematically and restricted to the main functions, the embossing unit of an embossing machine 11. On a machine frame 12, in particular seen in Fig. 2, two cooperating with each other Embossing cylinders 13, 14 are mounted, of which the tool cylinder 13 stamping tools 15 carries while the underlying impression cylinder in a sheetfed machine gripper for detecting and holding a bow 16 (double-dot-dashed), which forms the substrate, on the surface portions, Images, symbols or the like are imprinted on a carrier web 17 (dash-dotted) removably attached. The tools are appropriate adapted to the rounding of the tool cylinder and in their shape Metal platelets adapted to the area to be imprinted (in FIG. 2 simplified shown in a circle), by means of clamping devices on the Tool cylinder or a sleeve applied thereto according dee desired impact location be attached. The tool cylinder is heated, about the provided on the carrier web surface sections on the Substrate (sheet 16) to apply what they coated with a heat-sealing layer are. These can be holograms, foil images, metal layers etc. act. The carrier web will go along with the bow through the exact adjustable pressure gap 18 between the two cylinders 13, 14 passed, wherein the carrier web under certain circumstances to save carrier film gradually, possibly also with a braking and acceleration section, moves (see, for this, DE 37 13 666 C, EP 718 099 B and EP 1 155 831 B, to the also referred to for the purpose of disclosure).

The impression cylinder 14 is in bearings 19 in the machine frame about a horizontal Axis 20 rotatably mounted. He is about a drive gear 21 of a synchronous drive of the entire embossing machine is driven, so with the other units, such as sheet feeding, gripper operation, etc., synchronized.

The tool cylinder 13 is mounted about an axis 20 parallel to the axis 22, in a relative to the machine frame 12 movable machine part 23, which is referred to below as a rocker. The swingarm carries From Fig. 1 it can be seen that the Swingarm, which has one cheek on each side of the tool cylinder an axis 25 on the machine frame is mounted so that it is a linear drive 26, for example, a hydraulic cylinder or an electric Linear motor or a spindle drive or the like., For precision adjustment of Pressure gap 18 is pivotable. The connecting line between the Pivot axis 25 and the axis 22 of the tool cylinder is approximately horizontal and thus perpendicular to the connecting line between the axes 20, 22 of the two Cylinder.

It can also be seen that the rocker 23 by a rib 27 at a the swingarm receiving cutout of the machine frame in cooperation with a groove 28 in the outer contour of the rocker for axial guidance of the tool cylinder is received.

The tool cylinder 13 is driven by an electric drive 30 and is otherwise mechanically with respect to its drive with the synchronous drive coupled to the impression cylinder. The electric drive has an electric motor 31 on, namely a three-phase motor, possibly via a pre-gearbox 32 is directly connected to the shaft 33 of the tool cylinder 13.

The stator 34 of the electric motor, on the housing of the primary gear 32 is flanged, is not attached to the swingarm. The unit stator / gear housing 35 is provided with a support arm 36, which, as shown in FIG. 1 can be seen, essentially vertically to the swing extension or his Connecting line 37 between the axes 22 and 25 and thus approximately in the direction the connecting line 38 between the axes 20 and 22 extends. Of the Support arm is provided with a sliding seat in the form of a slot 39 on a stop pin 40, which is machine-mounted and of the machine frame 12 protrudes. Both cylinders 13, 14 are each provided with a transmitter 41, 42, the the respective rotational position, the rotational frequency, etc. of the cylinder in the form of electrical Give signals to a controller.

This control is shown schematically in FIG. The signals of the encoder 41 and 42 are fed to a controller 43, which is called an electronic Computer (computer) is shown. This contains an input keypad 44 and a memory for an operating program and for input values. Dependent on From this, output signals are generated which are sent via a data output 45 a speed control 46 are supplied, which is a controllable frequency converter contains. This generated from a network via a line 47th supplied current is a three-phase current, which in its frequency exactly the desired Speed of the electric drive 30 corresponds to which he over the three-phase connection 48 is supplied.

function

The embossing machine is the to be printed or with imprints substrate 16 to be provided, e.g. as a bow, fed by it detected by a gripper bar, not shown in the impression cylinder 14 and put it around the cylinder. The carrier web 17 for the surface areas to be impressed are passed through the pressure gap 18 guided and moved by a film drive, not shown, so that the areas of the surface to be imprinted, which effect this imprinting Tools 15 and those provided for the imprint Positions on the substrate 16 are simultaneously in the nip and the same Have speed or peripheral speed.

The nip became accurate using the linear actuator 26 adjusted so that the pressure required for the impression without damage of the substrate and the carrier web is exercised and the Heat from the heated tool cylinder 13, the sealing of the To be impressed surface portion on the substrate and the detachment effected by the carrier web. This setting is done under pivoting the rocker 23, wherein the support arm 36 due to its Sliding guide 39 this does not hinder.

The impression cylinder 14 is about the synchronous drive of the embossing machine driven at a predetermined, constant speed. In an ideal case, in which the effective diameters or perimeters Both cylinders 13 and 14 are the same, the control device 43 this speed, which tells you the encoder 42 as an input signal, too via the data output 45 of the speed control 46 perform the one Three-phase current generated, which corresponds in frequency to this speed, Of course, any possible slip, the gear ratio of the master gear, etc. are taken into account. Feedback receives the Control device via the encoder 41 to the tool cylinder, so that this exactly adjusts the speed.

If the effective diameter, for example, the tool cylinder as a circle of the tool surfaces under consideration an embossing depth, etc., are different, so is via the program stored in the controller a nonuniformity drive generated for the tool cylinder. Whose conditions are usually such that during the procedure the Tools 15 with carrier web, substrate and impression cylinder the Circumferential speed of the tool cylinder exactly the speed these components, i. the by speed and diameter certain peripheral speed of the Gegendurckzylinders correspond is, of course, as shown in Fig. 1 by the arrows 49, the cylinders 13, 14 rotate in opposite directions.

In the spaces and times free of embossing pressure can now the speed of the tool cylinder can be increased or decreased. This is by the frequency control of the electric motor even at higher Speeds in fractions of a revolution, i. within a revolution possibly also several times, possible. So that could be, after synchrony beyond that of a peripheral tool extension Angle 50 was made (for example, by acceleration opposite to the synchronous speed), in which to the next tool 15 remaining rotation angle range 51 a corresponding compensation (e.g., corresponding delay) to be already on this section of the circumference again the average of the synchronous speed to reach.

However, it is also possible by deliberate deviations from it Adjust tools for register accuracy. If, for example the circumferential distance between two tools 15 is slightly larger than the corresponding distance provided for the impressions on the Substrate, then by increasing the speed over the angle section 51 this be compensated.

The important thing is that in the sum of one revolution Average speed is generated, that of the synchronous speed of the impression cylinder corresponds so that the tools e.g. at a sheetfed machine always at the same location of the substrate used come. But here too, deliberate deviations are possible.

The corresponding settings for the respective size of the synchronous acceleration or delay sectors, the size of the deviations, the necessary acceleration and deceleration values etc. can be entered via the keypad 44, are in one Input memory stored and together with the basic program from the program memory under consideration and adjustment the encoder signals processed for speed control. Also one graphical representation of the speed curves or a setting by changing a velocity diagram, the Make setting clear.

In particular, if at higher speeds greater speed deviations, e.g. due to larger diameter deviations occur, are the acceleration and deceleration moments of the electric drive be generated, not insignificant. Energetically that is not Problem, because the braking energy can be fed back again. The But moments could be on the movable for setting storage the rocker 23 negative impact when the torques over the unit of gear housing and electric motor stator 32, 34, in the The following simplified referred to as the stator is transmitted to the rocker and expose them to constantly changing forces.

To avoid this, the stator is not flanged to the swingarm, but to record the reaction moments on the engine rotations supported via the support arm 36 directly on the machine housing. The reaction moments thus do not affect the rocker and keep them free in this respect.

Claims (8)

An embossing machine for transferring surface portions from a carrier web (17), such as a film, to a substrate (16), such as a sheet, where the substrate (16) and carrier web (17) are interposed between a first cylinder (19), e.g. Tool cylinder, on which a trained for transmitting the surface portions tool (15) is arranged, and a second cylinder (14), for example, a counter-pressure cylinder, run through and both cylinders (13, 14) at least during the transmission of the surface portions driven at substantially the same peripheral speed characterized in that the first cylinder (13) is driven by an electric drive (30) which is arranged substantially coaxially with the first cylinder (13) and in that a control device (43) is provided for the electric drive (30), on the one hand sync signals on the speed of the second cylinder (14) and on the other hand, data on desired deviations from de Synchronous speed is processed and converts them into control signals for preferably periodic speed changes of the first cylinder (13) during one revolution of the first cylinder (13). Embossing machine according to claim 1, characterized in that the electric drive (30) includes an electric motor, preferably a variable speed controllable via a frequency converter three-phase motor (31). Embossing machine according to claim 1 or 2, characterized in that the control of the electric drive (30) takes place such that diameter differences of the effective diameter of the two cylinders (13, 14) by adjustable, periodic changes in the peripheral speed of the first cylinder (13) during each one their turns are corrected, wherein the peripheral speed over the working peripheral area of a tool (15) to the first cylinder (13) changed by a substantially constant value and within a not occupied by the tool (15) peripheral area in the opposite direction of change by the during the previous change is returned. Embossing machine according to the preamble of claim 1, characterized in that an electric drive (30) driving the first cylinder (13) comprises an electric motor (31) with a stator (34, 35) and a rotor, the stator being mounted on another machine part ( 12) is stored as the first cylinder (13). Embossing machine according to Claim 4, characterized in that the first cylinder (13) is mounted on a machine part (23), in particular a rocker, which is adjustable in its distance from the second cylinder (14) and is mounted on the machine frame, and in that the stator rotatably mounted relative to the rotor (34, 35) of the electric drive (30) by means of a support arm (36) on the machine frame (12) is supported. Embossing machine according to claim 5, characterized in that the support arm (36) extends substantially vertically to the adjustable machine part (23) and between it and the machine frame 12) a substantially in the longitudinal direction of the support arm (36) movable connection (39) is provided is. Embossing machine according to claim 5, characterized in that the support arm (36) approximately in the extension of the pivot axis of the adjustable machine part has its support bearing. Embossing machine according to one of claims 4 to 7, characterized in that the adjustable machine part (23) by means of a linear drive (26), such as a Zydraulikzylinders, is held adjustable.

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