Film transfer unit and film transfer device having a film transfer unit

Abstract

The invention relates to a film transfer unit (28) for transferring a transfer layer from a carrier film to a printing material (17), wherein the transfer layer and the carrier film form a transfer film (2), having an unwinding roller (9) on an unwinding side of the film transfer unit (28) for providing the transfer film (2), a winding roller (13) on a winding side of the film transfer unit (28) for receiving used transfer film (2), and a synchronizing unit with adjustable guide elements (12, 15) for at least temporarily adapting the movement speed of the transfer film (2) to the speed of a printing material (17) in the transfer gap (3). According to the invention, multi-loop storage units are provided on the unwinding side and on the winding side for a synchronized storage of transfer film (2).

Description

[0001] Foil transfer unit and foil transfer device with a foil transfer unit

[0002] The present invention relates to a film transfer unit for transferring a transfer layer from a carrier film to a substrate, wherein the transfer layer and the carrier film form a transfer film, with an unwinder roll on an unwind side of the film transfer unit for providing the transfer film, with a rewinder roll on a rewind side of the film transfer unit for receiving used transfer film, and with a timing device with adjustable guide elements for adjusting the movement speed of the transfer film at least temporarily to the speed of a substrate in the transfer gap and / or for timing the storage of the transfer film.

[0003] Furthermore, the present invention relates to a foil transfer device, in particular a cold foil stamping machine, with a foil transfer unit of the type described above and with a printing machine.

[0004] Foil transfer machines are used to enhance printed products, for example, to create glossy effects. Foil transfer machines can be divided into hot foil stamping machines and cold foil stamping machines. In cold foil stamping machines, the transfer layer is applied to the substrate using only pressure, without the additional application of heat. Typically, cold foil stamping machines with a pre-printing unit apply adhesive to a sheet of substrate, leaving an adhesive image. This adhesive is then used in a foil transfer unit to peel a transfer layer from a transfer foil, allowing the transfer layer to adhere to the sheet in specific areas.

[0005] A problem with this foil transfer technique is that the transfer foil must move at the same speed as the substrate during the transfer process, and that typically only small areas of the substrate are intended to be covered with the transfer layer. In particular, a transfer cylinder involved in creating the transfer gap often has a so-called channel in which a printing blanket may be attached. No transfer of the transfer layer can occur in the area of ​​this channel. Therefore, a control system is implemented such that the substrate dips into the transfer gap between the transfer cylinder and an impression cylinder when the channel is not located within the substrate area. Other areas where transfer foil is transported unused through the transfer gap are those where no transfer layer is intended to be applied to the substrate.

[0006] To improve the utilization of the transfer foil and reduce consumables, it is known to move the transfer foil over a pair of dancer rollers that move cyclically in sync with the channel of the transfer cylinder. Once a substrate has been completely transported through the transfer gap and / or a channel of the transfer cylinder is located within the transfer gap, the transfer foil can be slowed down, stopped, and preferably retracted. This is achieved by moving an unwinding-side dancer and a rewinding-side dancer by motors in a braking direction, either uniformly or slightly asynchronously. This braking action is generally implemented when no transfer layer is to be applied to the substrate.

[0007] During the uniform or slightly asynchronous movement of the dancers, a dancer on the unwinding side stores transfer film unwound from the still-moving supply or unwinder roll, while a dancer on the rewinding side simultaneously releases transfer film onto the collecting or rewinder roll. This ensures a certain degree of web tension consistency in the area of ​​the supply and collecting rolls. After deceleration, the transfer film and substrate must then be rapidly accelerated and brought into synchronization so that the transfer layer can be applied. The timed stopping and, preferably, retraction, as well as the subsequent synchronization of the transfer film web and substrate movements, is characterized by high machine dynamics, which leads to considerable stress on the adjustable guide elements of the timing device.

[0008] Rapid movements, accelerations, and decelerations of the transfer foil during the alternating braking, retraction, and re-acceleration to synchronization with the substrate place high demands on the dynamics of the foil transfer unit and limit the possible cycle rates. Although cycle rates of up to 15,000 cycles per hour can already be achieved with known foil transfer units, a further increase in cycle rates is not possible with these machines due to their dynamics. This is primarily due to the strong accelerations of the dancers during the braking and retraction of the transfer foil, alternating with its subsequent acceleration to synchronization with the substrate.

[0009] The object of the present invention is to provide a foil transfer unit and a foil transfer device that allow for an increase in cycle rates during the deceleration and, preferably, retraction of the transfer foil and the subsequent re-acceleration of the transfer foil to synchronize with the substrate, while simultaneously minimizing the maximum acceleration of the adjustable guide elements of the indexing device that move during indexing. In particular, it is an object of the invention to provide a foil transfer unit that, compared to foil transfer units known from the prior art, achieves higher cycle rates with the same or even lower maximum acceleration of the adjustable guide elements.

[0010] Another aspect of the task is to provide a foil transfer unit and a foil transfer device that enable high torque transmission to the adjustable guide elements of the timing device during the indexing of the transfer foil, with low component stress and load.

[0011] Another aspect of the task is to provide a foil transfer machine and a foil transfer device that are characterized by a simple and space-saving design.

[0012] The object of the invention is achieved by the subject matter of independent claims 1 and 14. The dependent claims relate to advantageous embodiments of the invention.

[0013] The foil transfer unit according to the invention has a multi-loop storage unit on the unwind side and a multi-loop storage unit on the rewind side for storing transfer foil during indexing. The indexed storage of transfer foil is achieved via several adjustable or movable guide elements of the indexing device on the unwind side and several adjustable or movable guide elements on the rewind side, which form dancers of the multi-loop storage units. Indexing shafts and / or dancer rollers are preferably provided as dancers. Compared to known foil transfer units with single-loop storage units, the use of multi-loop storage allows for higher cycle rates when stopping and, preferably, retracting the transfer foil and accelerating back to synchronous speed with the substrate, and preferably the same or even lower maximum accelerations of the guide elements or the dancers.

[0014] The use of multiple loop storage units on the unwind and rewind sides of the indexing device leads to an increase in the mass of the moving components and involves additional design complexity. According to the invention, however, the disadvantages of increased mass are deliberately accepted in order to achieve an acceleration advantage at high cycle rates compared to the single-loop dancers used in known foil transfer machines.

[0015] The term "cycle" as used in the invention refers to the complete movement cycle of the transfer film web during a work process, wherein a cycle typically comprises the following phases on the unwind side:

[0016] 1. Standstill and retraction: The transfer film is slowed down on the unwind side, briefly stopped, and preferably a certain length of the film is retracted to provide a new section for transfer onto the substrate.

[0017] 2. Storage and Synchronization: The retracted film is taken into the loop storage, where it is temporarily stored in a controlled loop shape. The storage enables a continuous supply of the film without abrupt stops or voltage fluctuations.

[0018] 3. Synchronization with the substrate: The foil is synchronized again with the speed of the substrate and released, so that the transfer layer is transferred exactly to the desired location on the substrate.

[0019] 4. New cycle start: After completion of the transfer, the next cycle begins with another stop and, preferably, retraction of the film. The term "acceleration" within the meaning of the invention refers to the acceleration of the adjustable guide elements or the dancers of the multi-loop storage on the unwind side and on the rewind side during their adjustment movement in the braking direction, i.e., when decelerating or stopping and, preferably, retracting the transfer film web, and in the acceleration direction, i.e., when accelerating the transfer film web back to synchronization with the substrate or when synchronizing the transfer film web and the substrate.

[0020] The adjustment movement of the guide elements or dancers of the multi-loop storage unit results in a material length change factor more than twice that of a single-loop storage unit. Preferably, a double-loop storage unit is provided on both the unwinding and winding sides. Each double-loop storage unit has two adjustable guide elements or dancers, which results in a material length change factor four times that of a single-loop storage unit with only one dancer, resulting in a material length change factor that is twice that of a single-loop storage unit with only one dancer.

[0021] In comparison with a foil transfer unit with a timing device that provides a single-loop buffer on both the unwind and rewind sides, significantly higher clocking rates can be achieved with a foil transfer unit according to the invention with double-loop buffers at lower maximum accelerations of the dancers, as shown in the following table:

[0022] Cycles 1 / h Max. a [m / s2] Cycles 1 / h Max. a [m / s2] finishing length

[0023] Single loops Single loops Double loops Double loops [mm]

[0024] dancer dancer dancer dancer

[0025] 650 15000 67 20000 60 700 15000 82 18000 62 720 15000 95 17000 62 750 12500 72 15000 56

[0026]

[0027] By using double-loop storage on the unwinding and winding sides, for example, high clock speeds of between 15,000 and 20,000 clock speeds per hour are possible, and at these clock speeds, comparatively low maximum accelerations of the dancers in the range of 40 to 70 m / s². 2 , especially between 50 and 65 m / s 2 This means that the invention does not exceed maximum accelerations of the dancers, which are even lower than the maximum accelerations of the dancers of single-loop storage units on the unwind and rewind sides of known film transfer machines.

[0028] Preferably, a mechanically synchronized or coupled adjustment of the unwind-side guide elements and the rewind-side guide elements is provided. This coupled adjustment ensures that the unwind-side and rewind-side dancers always move together and synchronously. This guarantees that the unwind-side and rewind-side dancers are precisely adjustable and movable in relation to each other. This automatically balances the web tension on both sides, resulting in consistent web tension. According to the invention, the adjustable guide elements on both the unwind and rewind sides exhibit the same movement characteristics. The coupling refers to the adjustment movement of the guide elements or dancers in both the braking and acceleration directions.

[0029] In the context of the invention, a mechanically synchronized adjustment of the unwinding-side guide elements and the winding-side guide elements is understood to mean, in particular, a movement coupling of the guide elements on the unwinding side with the guide elements on the winding-side, which only allows a common linear adjustment of the guide elements in one direction towards the winding-side and in one direction towards the unwinding side, but no linear relative movement between the unwinding-side guide elements and the winding-side guide elements in the direction towards the winding-side or towards the unwinding side.

[0030] The kinematic coupling of the unwinding-side guide elements and the winding-side guide elements, and the resulting mechanically synchronized adjustment of the guide elements, results in a mutual cancellation of the web tension acting on the unwinding-side guide elements on the one hand and on the winding-side guide elements on the other, which would have to be maintained on both the unwinding and winding sides if the unwinding-side guide elements were decoupled from the winding-side guide elements.A preferred embodiment of the invention provides that the adjustable guide elements on the unwind side and the adjustable guide elements on the wind-up side are received and / or held in a common movable guide unit, in particular designed as a indexing guide carriage, and that the guide unit together with the adjustable guide elements is adjustable or movable at a defined rate along a guide rail or a linear system. By being received in the movable guide unit, the unwind-side guide elements and the wind-up-side guide elements are mechanically coupled, so that synchronized adjustment of the guide elements is possible.The guide unit allows for simple, dynamic adjustment of the loop length of the unwinding-side multi-loop storage unit and the rewinding-side multi-loop dancer by adjusting the guide unit along a guide rail or linear system. Furthermore, integrating the adjustable guide elements into a single guide unit results in a simple and space-saving design.

[0031] Preferably, the unwinding-side guide elements and the winding-side guide elements can be adjustable together with the guide unit. Preferably, a drive system is provided for driving the guide unit and thus for the synchronized, coupled adjustment of the adjustable unwinding-side guide elements and the adjustable winding-side guide elements. Particularly preferably, the drive is effected via the traction elements of several traction element drives, especially via the toothed belts of several belt drives.

[0032] The adjustable unwinding-side guide elements and the adjustable rewinding-side guide elements can be provided in a frame designed in the manner of an interchangeable cassette, wherein the frame can be inserted into and removed from an opening of the film transfer unit having receiving elements for receiving the frame.

[0033] In a printing unit converted into a foil transfer unit, for example, a foil transfer module can be mounted on the printing unit. If the foil transfer module is mounted on a conventional printing unit and essentially consists of guide elements, a feed roller, and a collection roller, and if a timing device is also provided, then by housing this timing device within a cassette frame, the entire timing device can be easily removed from the foil transfer unit, thus freeing up an area above the printing unit for access to an ink box of the printing unit.

[0034] The drive for the adjustable guide elements can be housed within the frame of a cassette. Alternatively, the drive can be located outside the frame and connected via a coupling to a drive mechanism for the adjustable guide elements, such as a toothed belt of a belt drive. The drive can be designed to be detachable for inserting and removing the cassette. The drive can then be fixed to a frame within the foil transfer unit and connected via at least one coupling element to an inserted cassette frame.

[0035] Particularly preferably, several unwind-side indexing shafts and / or dancer shafts can be provided as unwind-side guide elements, and several rewind-side indexing shafts and / or dancer shafts as rewind-side guide elements, which are then, more preferably, received or mounted in a movable guide unit of the type described above and can be adjusted or moved together with the guide unit. Precise, simultaneous adjustment of the indexing shafts, which are mechanically coupled to each other via the movable guide unit, is possible by adjusting the guide unit, preferably via traction elements from two traction element drives, in particular toothed belts from two belt drives.

[0036] A double-sided or bi-ended drive for the indexing shafts is particularly preferred. A double-sided shaft drive offers significant advantages in applications with high demands on web guidance and material protection. A synchronized double-sided drive allows for consistent web tension control, which is especially beneficial for sensitive substrates. With a double-sided drive control, the indexing shafts can react more quickly and precisely to changes in web tension. Particularly at high speeds or under varying loads, the double-sided drive ensures stable web guidance.

[0037] A double-sided shaft coupling of the indexing shafts via traction drives enables precise parallel adjustment of the unwinding-side indexing shafts and the winding-side indexing shafts. A structurally preferred embodiment of the invention provides that a first traction drive with at least one traction element is provided, which connects the indexing shafts at a first shaft end to a first drive motor, and that a second traction drive with at least one second traction element is provided, which connects the indexing shafts at a second shaft end to a second drive motor.

[0038] Particularly preferably, the indexing shafts are mounted or supported in a common movable guide unit, especially designed as an indexing guide carriage, wherein the guide unit is driven on both sides, in particular wherein a first traction drive with at least one traction element is provided that connects the guide unit on the side of the first shaft end of the indexing shafts to a first drive motor for power transmission, and wherein a second traction drive with at least one second traction element is provided that connects the guide unit on the side of the second shaft end of the indexing shafts to a second drive motor. This ensures that the guide unit can be adjusted on both sides at the same speed, i.e., synchronously in the braking or acceleration direction of the indexing or dancer shafts. Synchronous power transmission is ensured via the guide unit.

[0039] For the combined drive of the unwinding-side guide elements and the winding-side guide elements, several drive motors, in particular two drive motors, are preferably provided. The drive motors can generate a sufficiently high drive torque for the combined adjustment movement of the guide elements.

[0040] To transmit drive torque to a toothed belt in a belt drive, each drive motor can be connected to a drive pulley via a motor shaft and, if necessary, a coupling with a coupling shaft. The drive motor rotates the drive pulley, which is coupled to the toothed belt. This allows the rotary motion of the motor shaft to be converted into a linear motion of the drive belt with high precision. A linear movement of the toothed belt towards the winding side (braking direction) or towards the unwinding side (acceleration direction) then results in a corresponding adjustment movement of the indexing shafts or an adjustable guide unit that accommodates the indexing shafts. Such a setup with drive motor, pulleys, and toothed belt can be provided on both sides of the indexing shafts or on both sides of a guide unit in which the indexing shafts are accommodated or supported.

[0041] To synchronize the two traction drives, several synchronization shafts can be provided, with each drive motor driving one synchronization shaft. The synchronization shaft synchronizes the movement of the traction elements of the two traction drives should there be an unequal torque transmission from the two drive motors to the traction elements.

[0042] To avoid the transmission of differential torques via the traction elements, a particularly preferred embodiment of the invention provides that both drive motors drive the same synchronous shaft. In this context, a design feature may provide that each drive motor is connected to a drive pulley via a motor shaft and, optionally, a coupling with a coupling shaft for torque transmission. Each drive pulley drives a drive belt of a belt drive, and the drive motors are arranged on opposite drive sides of the indexing shafts or on opposite drive sides of a guide unit provided for the common, coupled adjustment of the indexing shafts. The drive pulleys are then connected to each other via a common synchronous shaft, so that both drive motors drive the synchronous shaft.As a result, both drive motors are coupled and synchronized via a common synchronous shaft, ensuring that both sides of the timing shafts rotate in unison, even if different torque values ​​are transmitted from the drive motors to the respective belt drives. The common synchronous shaft serves to synchronize the rotational movement of both drive motors and guarantee an even load distribution.

[0043] The drive motors can preferably be assigned to different shaft ends of the indexing shafts and located on the same winding side, particularly on the unwinding side of the film transfer unit. This preferred embodiment provides that the drive motors drive a common synchronous shaft, allowing for a space-saving, rigid, and highly dynamic design.

[0044] Alternatively, the drive motors can be assigned to different shaft ends of the timing shafts, but located on different winding sides, with one drive motor on the unwinding side and one on the winding side. In this embodiment, two synchronous shafts are driven by the drive motors, with the driven synchronous shafts located on different winding sides of the timing device. This embodiment is characterized by less complex control technology.

[0045] By using multiple loop accumulators on the unwind and rewind sides of the film transfer unit according to the invention, in particular by using double loop accumulators, and by coupling or synchronizing the dancer movements on the unwind and rewind sides, in particular by accommodating the dancers in a common adjustable guide unit, lower drive power per drive motor and for the overall system can be achieved with the drive concepts described above compared to using single loop accumulators and decoupling the dancer movements on the unwind and rewind sides. This has been shown by comparative calculations carried out in connection with the invention.

[0046] The invention is described below with reference to the drawing. The drawing shows:

[0047] Fig. 1 shows a web feed scheme of a known film transfer machine with a single-roll buffer on the unwind side and a single-loop buffer on the rewind side at T indexing in a view of an operator side of the film transfer machine;

[0048] Fig. 2 shows a web feed scheme of a film transfer machine according to the invention with a double loop storage unit on the unwind side and with a double loop storage unit on the rewind side during indexing in a view of an operating side of the film transfer machine;

[0049] Fig. 3 shows a schematic representation of a drive system of a timing device of a film transfer machine according to a first embodiment of the invention, and Fig. 4 shows a schematic representation of a drive system of a timing device of a film transfer machine according to a second embodiment of the invention.

[0050] Fig. 1 shows a web feed scheme of a known foil transfer unit 1 during indexing in a view of the operator side of the foil transfer unit 1. The foil transfer unit 1 can be part of a foil transfer device, which can essentially consist of a conventional printing press and a printing unit converted into a foil transfer unit 1.

[0051] In the foil transfer unit 1, a transfer foil 2 is guided through a transfer gap 3. The transfer gap 3 is the original printing gap of the repurposed printing unit and is formed by a transfer cylinder 4 and an impression cylinder 5. The transfer cylinder 4 can be a conventional blanket cylinder. Like a conventional printing unit, the foil transfer unit 1 can include a plate cylinder 6 and an inking unit 7 with an ink fountain 8, which can be used to ink a printing plate, if present, on the plate cylinder 6.

[0052] For use with the foil transfer unit 1, the printing unit can be modified so that a foil transfer module is mounted on it. The foil transfer module includes a foil supply or unwinder roll 9, which holds at least one web of transfer foil 2. Alternatively, different partial rolls of transfer foil 2, for example with different colors, can be provided. For this purpose, the unwinder roll 9 can be mounted on a friction shaft, which is not shown.

[0053] To advance the transfer foil 2 from the unwinder roll 9, an unwind-side advance 10 is provided, which pulls the transfer foil 2 away from the unwinder roll 9 by driving it away.

[0054] To guide the transfer film 2 to the transfer gap 3, guide elements 11, 12 are provided on the unwind side, and guide elements 14, 15 are provided on the winder side to guide the transfer film 2 from the transfer gap 3 to a collecting or rewinding roller 13. To reduce film consumption and improve the utilization of the transfer film 2, the guide elements 11, 14 are fixed to the frame, while the guide elements 12, 15 are designed or provided as movable dancers. By means of a further winder-side projection 16, the transfer film 2 is driven towards the rewinding roller 13. The rewinding roller 13 can also be mounted on a friction shaft (not shown).

[0055] The unwinder roller 9 can be located on a friction shaft (not shown) and is driven at a speed lower than the speed of a sheet of substrate 17. The transfer foil 2 is unwound from the unwinder roller 9 by the front feed 10, the roller of the front feed 10 being driven at a higher speed than the friction shaft of the unwinder roller 9. However, the front feed 10 is driven at a lower speed than the substrate 17.

[0056] The unwound transfer film 2 is then guided through the transfer gap 3 via a movable guide element 12 (or front dancer) on the winding side and further deflection rollers 19. Behind the transfer gap 3, the transfer film 2 is fed via further deflection rollers 20 to the movable guide element 15 (or rear dancer) on the winding side, which deflects the transfer film 2 and feeds it to the winding-side feeder 16.

[0057] A sheet of substrate 17, together with the transfer foil 2, is guided over the impression cylinder 5 and through the transfer gap 3. During the transfer of a transfer layer (not shown) from the transfer foil 2, the transfer foil 2 and the substrate 17 are moving in sync or at the same speed.

[0058] The transfer cylinder 4 has a printing blanket, which is not shown. The printing blanket is clamped over a channel 21 of the transfer cylinder 4.

[0059] When a leading edge of the channel 21 enters the transfer gap 3, the web tension between the unwinding-side dancer 12 and the transfer gap 3 collapses. During the transfer of a transfer layer onto the substrate 21, the sum of the speeds of the leading feeder 10 and the unwinding-side dancer 12 equals the speed of the substrate 21. For this purpose, the dancer 12 is moved linearly in an acceleration direction 23 according to the double arrow 22. Contact between the leading edge of the channel 21 and the counter-pressure cylinder 5 decouples the unwinding-side dancer 12 and the rewinding-side dancer 15. To compensate for the collapsing web tension, the unwinding-side dancer 12 is then driven by a motor 24 so that it is initially accelerated sharply in the braking direction 26. This achieves a constant web tension in this area.A control device 25 is provided for controlling the motor 24.

[0060] If the channel 20 lies completely within the area of ​​the transfer gap 3, the unwinding-side dancer 12 is moved with a lower acceleration in the braking direction 26, whereby the transfer film 2 comes to a standstill and is finally retracted.

[0061] To compensate for a drop in web tension due to channel 21 on the take-up side, the take-up-side dancer 15 can initially be moved with a lower acceleration in the braking direction 26. Subsequently, the dancer 15 can then be moved with a higher acceleration so that the transfer film 2 can come to a standstill. For this purpose, the control unit 25 is connected to another motor 27, which drives the take-up-side dancer 15.

[0062] Fig. 2 shows a web feed diagram of a foil transfer unit 28 for transferring a transfer layer from a carrier film 2 onto a substrate 17. Functionally identical and / or structurally identical components and features of the foil transfer units 1, 28 shown in Figs. 1 and 2 are marked with the same reference numerals.

[0063] The film transfer unit 28 from Fig. 2 has a plurality of adjustable guide elements 12 on the unwind side of the film transfer unit 28 and a plurality of adjustable guide elements 15 on the rewind side of the film transfer unit 28. The movable guide elements 12, 15 are designed as indexing and / or dancer shafts. The guide elements 12, 15 form dancers of an unwind-side double loop storage unit and a rewind-side double loop storage unit.

[0064] By incorporating double-loop accumulators on the unwind and rewind sides of the film transfer unit 28, significantly higher cycle rates are achieved with lower maximum acceleration of the adjustable guide elements 12, 15 compared to the film transfer unit 1 shown in Fig. 1, which has single-loop accumulators on both the unwind and rewind sides. Not shown in detail, the film transfer unit 28 from Fig. 2, like the film transfer unit 1 from Fig. 1, can have an inking unit 7 with ink box 8 and plate cylinder 6, with the plate cylinder 6 acting against the transfer cylinder 4 as shown in Fig. 1.

[0065] As described in Fig. 1, the foil transfer unit 28 can be obtained by modifying a printing unit, for which purpose a foil transfer module is mounted onto a printing unit. The outline 29 in Fig. 2 schematically shows the foil transfer module, which can include the unwinder roll 9 and the rewinder roll 13, the unwind-side extension 10, the rewind-side extension 16, the guide elements 11, 14 provided for guiding the carrier foil 2, and the movable guide elements 12, 15 or dancers, which guide the transfer foil 2 to the transfer slot 3 of the printing unit and away from the transfer slot 3.

[0066] The printing unit, together with at least one application unit and / or one coloring unit, can be part of a foil transfer device, which is schematically indicated in Fig. 2 by the outline line 30.

[0067] The adjustable unwinding-side guide elements 12 and the adjustable winding-side guide elements 15 are received in a movable guide unit 31, which is shown only schematically in Fig. 2 and can in particular be designed as a indexing guide carriage, which is adjustable in a defined indexing sequence along a frame-fixed linear guide, in particular at least one guide rail.

[0068] The movable guide elements 12, 15, which are received in or mounted on the guide unit 31, can then be adjusted together or coupled by linear movement of the guide unit 31 to index the transfer film 2 as described above with reference to Fig. 1, in order to decelerate and, preferably, stop or retract the transfer film 2 as described above with reference to Fig. 1. For this purpose, the movable guide elements 12, 15 are driven and adjusted by a drive system 32, 33 (Figs. 3 and 4). The drive system 32, 33 with two drive motors 35, 36 and a control device for controlling the drive motors 35, 36 is not shown in Fig. 2. Figs. 3 and 4 each show a schematic top view of a drive system 32, 33 of the film transfer unit 28 shown in Fig. 2.

[0069] The drive system 32, 33 moves the movable guide elements 12, 15 to transport the carrier film 2 to the transfer gap 3 in the direction of the acceleration arrow 23 (Fig. 2). The unwinding-side feed 10 unwinds the transfer film 2 from the unwinder roll 9 and drives it at a first speed. The feed speed, together with the speed of the movable guide elements 12, determines the resulting overall speed of the transfer film 2 within the transfer gap 3, which is matched to the movement speed of the substrate 17.

[0070] By arranging the adjustable guide elements 12, 15 in the guide unit 31, the guide elements 12, 15 can be moved together, so that a mechanically synchronized adjustment of the guide elements 12, 15 is possible by an adjustment movement of the guide unit 31.

[0071] The indexing elements of the film transfer unit 1 can be provided in the form of a modular indexing device 34, which comprises the adjustable guide elements 12, 15 and, preferably, fixed guide elements 11, 14, as well as optionally parts of the drive system 32, 33. The indexing device 34 can have a frame designed in the form of an interchangeable cassette 34, which can be inserted into and removed from an opening of the film transfer unit 28 (not shown in Fig. 2).

[0072] In the drive system 32 shown in Fig. 3, two drive motors 35, 36 are provided, which are connected to two drive pulleys 43, 44 of two belt drives 45, 46 via motor shafts 37, 38 and couplings 39, 40 and coupling shafts 41, 42 for torque transmission. Each drive motor 35, 36 drives one drive pulley 43, 44. The drive pulleys 43, 44 are connected to output pulleys 49, 50 via toothed belts 47, 48.

[0073] The toothed belts 47, 48 are connected to, or kinematically coupled to, the guide unit 31 shown in Fig. 2, so that the guide unit 31 can be linearly adjusted or moved by a movement of the toothed belts 47, 48. A torque transmission from the drive motors 35, 36 to the drive belt pulleys 43, 44 results in a coupled, linear adjustment movement of the toothed belts 47, 48 and thus of the guide unit 31. Together with the guide unit 31, the unwinding-side guide elements 12 and the winding-side guide elements 15, which are mounted in the guide unit 31 and designed as indexing shafts or dancer shafts, are adjusted or moved synchronously. For this purpose, the indexing shafts can be connected to, or supported on, the guide unit 31 at both ends via attachments 51, 52.

[0074] In the embodiment shown in Fig. 3, the two drive motors 35, 36 are arranged on the same winding side of the film transfer unit 28, in this case on the unwinding side. Both drive motors 35, 36 drive the unwinding-side synchronous shaft 53, which connects the two drive belt pulleys 43, 44. A winding-side synchronous shaft 54 ​​is not directly driven and connects the two output belt pulleys 49, 50. This ensures that any differential torque that may occur is compensated for via the unwinding-side synchronous shaft 53. Furthermore, the drive system 32 shown in Fig. 3 is characterized by high rigidity and dynamics.

[0075] In contrast, in the embodiment of the drive system 33 shown in Fig. 4, the drive motors 35 and 36 are arranged on different winding sides, with the unwinding-side drive motor 35 driving the unwinding-side synchronous shaft 53 via the drive belt pulley 43, while the winding-side drive motor 36 drives a winding-side drive belt pulley 44. This embodiment is characterized by simple control technology.

[0076] As described above, the indexing elements of the film transfer unit 1 can be provided in the form of a modular indexing device 34, which comprises the adjustable guide elements 12, 15 and, preferably, fixed guide elements 11, 14, as well as optionally parts of the drive system 32, 33. The indexing device 34 can have a frame designed in the form of an interchangeable cassette 34, which can be inserted into and removed from an opening of the film transfer unit 28 (not shown in Fig. 2).

[0077] If the interchangeable cassette includes the two drive motors 35, 36, the drive motors 35, 36 can be connected to a control device (not shown) when the interchangeable cassette is inserted into the opening to pulse a sheet of the substrate 17 through the transfer gap 3. Alternatively, the drive motors 35, 36 can be fixed to the frame and remain in the foil transfer module 1 when the interchangeable cassette is removed from the opening. In this case, the drive motors 35, 36 are located outside the interchangeable cassette and can be coupled to the belt drives 45, 46 via the couplings 43, 44 for torque transmission. Reference numeral list:

[0078] 1 foil transfer unit 30 29 outline

[0079] 2 Transfer foil 30 outline line

[0080] 3 Transfer gap 31 Guide unit 4 Transfer cylinder 32 Drive system 5 Counter pressure cylinder 33 Drive system 6 Plate cylinder 35 34 Indexing device 7 Inking unit 35 Motor

[0081] 8 paint boxes, 36 motors

[0082] 9 Unwinder roller 37 Motor shaft

[0083] 10 Preferred 38 Motor shaft

[0084] 11 Guide element 40 39 Coupling

[0085] 12 Guide element 40 Coupling

[0086] 13 Winder roller 41 Clutch shaft 14 Guide element 42 Clutch shaft 15 Guide element 43 Pulley

[0087] 16 Preferred 45 44 Pulley

[0088] 17 Printing material 45 Belt drive 19 Deflection pulley 46 Belt drive 20 Deflection pulley 47 Timing belt 21 Channel 48 Timing belt 22 Double arrow 50 49 Pulley

[0089] 23 Acceleration direction 50 Pulley

[0090] 24 Engine 51 Attachment

[0091] 25 Control unit 52 Attachment

[0092] 26 Braking direction 53 Synchronous shaft 27 Motor 55 54 Synchronous shaft 28 Foil transfer unit

Claims

Patent claims:

1. Film transfer unit (28) for transferring a transfer layer from a carrier film to a substrate (17), wherein the transfer layer and the carrier film form a transfer film (2), with an unwinder roll (9) on an unwind side of the film transfer unit (28) for supplying the transfer film (2), with a rewinder roll (13) on a rewind side of the film transfer unit (28) for receiving used transfer film (2), and with a timing device (36) with adjustable guide elements (12, 15) for adjusting the movement speed of the transfer film (2) at least temporarily to the speed of a substrate (17) in the transfer gap (3), characterized in that a plurality of adjustable unwind-side guide elements (12) and a plurality of adjustable rewind-side guide elements (15) are provided.wherein the unwinding-side guide elements (12) form dancers of an unwinding-side multi-loop storage unit and the winding-side guide elements (15) form dancers of a winding-side multi-loop storage unit, in particular wherein a double-loop storage unit is provided on the unwinding side and on the winding-up side respectively.

2. Foil transfer unit (28) according to claim 1, characterized in that a mechanically synchronized, coupled adjustment of the adjustable unwinding-side guide elements (12) and the adjustable winding-side guide elements (15) is provided.

3. Foil transfer unit (28) according to one of the preceding claims 1 or 2, characterized in that the adjustable unwind-side guide elements (12) and the adjustable rewind-side guide elements (15) are received and / or held in a movable guide unit (31), in particular designed as a indexing guide carriage, and that the guide unit (31) is adjustable in a defined indexing sequence along a frame-fixed guide, in particular at least one guide rail.

4. Film transfer unit (28) according to one of the preceding claims, characterized in that a drive system (32, 33) is provided for driving the guide unit (31) and for synchronously, coupled adjustment of the adjustable unwind-side guide elements (12) and the adjustable rewind-side guide elements (15).

5. Film transfer unit (28) according to one of the preceding claims, characterized in that the adjustable unwind-side guide elements (12) and the adjustable rewind-side guide elements (15) are formed by indexing shafts or dancer shafts and that the indexing shafts or dancer shafts are driven on both sides.

6. Foil transfer unit (28) according to one of the preceding claims, characterized in that several belt drives (45, 46) are provided for driving the indexing shafts or dancer shafts on both sides and / or that two drive motors (35, 36) are provided for driving the belt drives (45, 46).

7. Foil transfer unit (28) according to claim 6, characterized in that synchronization of the two belt drives (45, 46) is provided via several synchronization shafts (53, 54), wherein each drive motor (35, 36) drives a synchronization shaft (53, 54).

8. Foil transfer unit (28) according to one of the preceding claims, characterized in that both drive motors (35, 36) drive a common synchronous shaft (53).

9. Foil transfer unit (28) according to one of the preceding claims, characterized in that both drive motors (35, 36) are provided on the same winding side, in particular on the unwinding side.

10. Foil transfer device comprising a printing machine and a foil transfer unit (28) according to one of the preceding claims.

Images