WO2011153975A2

WO2011153975A2 - Thermoforming station, thermoforming system, method for forming or stamping and articles produced

Info

Publication number: WO2011153975A2
Application number: PCT/DE2011/000369
Authority: WO
Inventors: Wolfgang Frey
Original assignee: Kiefel Gmbh
Priority date: 2010-06-07
Filing date: 2011-04-07
Publication date: 2011-12-15
Also published as: US20130152660A1; DE112011101935A5; WO2011153975A3; EP2576186A2; DE102010054976A1

Abstract

The invention relates to a thermoforming station in which motors are oriented so as to rotate in the same sense on the drive of the upper table (33) and of the lower table (32) of the thermoforming station whilst actuating elements (31) are oriented in counterrotating manner. In addition, a wobbling table mounting (37) is proposed. Further disclosed is a table-guiding system which is separate from the upper yoke supports. Spring assemblies (46) for holding overload supports are also mentioned. The thermoforming station (26) operates as a whole more reliably and is very easily maintained.

Description

Thermoforming, thermoforming, molding or stamping

manufactured articles

The invention relates to a thermoforming station, a thermoforming plant with such a station, a method for molding or stamping and an article produced therewith.

[02] It has proven useful to carry out thermoforming processes on specially equipped systems using thermoforming tools. The actual core step is carried out at the thermoforming station. A heated base material is deformed there by means of a molding tool with an upper tool and a lower tool under the action of force of a press.

[03] Actuators act on the mold, more precisely on the upper tool and the lower tool. A lower drive acts on the lower tool and lifts this up to the thermoforming process against the upper tool. At the same time, an upper drive engages the upper tool and lowers it to form against the lower tool.

[04] Also conceivable are thermoforming stations in which one of the two tool parts stands and only the other part is moved.

[05] Part of every drive is a drive unit, usually a motor. Usually, each motor performs rotational work. Via a gearbox, usually an eccentric shaft and a toggle lever, the rotational motion output of the motor is translated into the linear motion on the tool.

CONFIRMATION COPY [06] Depending on the specific design of the thermoforming station, a driven tool part may be driven by one or more motors via one or more toggle levers and one or more eccentric shafts and one or more other actuators. [07] In the context of the present application, these variants are to be assumed to be known to the person skilled in the art. For easier readability of the present application is therefore not linguistically further differentiated. Rather, an indefinite article is used to describe "one or more" items unless it is contextually implied that "exactly one" item is meant.

[08] However, the rotating motors on a thermoforming station, usually two motors, namely one on the upper tool and one on the lower tool, can introduce unwanted vibrations into the tools or the station frame. This is especially true when the motors are arranged in the same direction. This is the case when two motors or when more than two motors exert torque about an axis imagined by the station, these torques adding together. In particular, at each startup or braking then adding rotary pulses are applied to a tool part or on the thermoforming station.

[09] This phenomenon is particularly noticeable when either one or all or at least more than the other direction continuously running motors are arranged on one tool part. This phenomenon can also occur if, with reference to the entire thermoforming station, there are a plurality of, in particular all, under certain circumstances also more than counter-rotating corotating motors.

[10] In simple words, the problems can occur when either on one of the two tools or on both tools in each case or above the entire thermoforming station experiences an imbalance of applied torques and angular momentum.

[11] EP 1 832 408 A2 proposes a thermoforming station in which the two motors rotate in opposite directions on the lower tool. The induced by the two motors angular momentum therefore cancel each other out.

The invention has for its object to provide an improved thermoforming system.

According to a first aspect of the invention, this object is achieved by a thermoforming station having a forming tool with an upper and a lower tool and with a drive for the forming tool for moving into an open and a closed position, wherein the drive has two drive units, which In operation, each having a drive direction of rotation and act to move the mold via an actuating element on the mold, wherein the actuators each have a Betätigungselementdrehsinn in operation, and wherein two drive units are arranged for the mold with gleichläufigem drive direction and at the same time via gear for driving the actuators are arranged with opposite actuator rotation direction.

[14] For this purpose, it is explained conceptually that the "actuating element rotation direction" is the counterpart to the drive direction of rotation, ie rotational movements on the actuating element are to be considered for this purpose.

[15] The invention has recognized that the quite complicated opposing orientation of the rotational sense of two motors proposed by EP 1 832 408 A2 is not necessary. Rather, the real key to a quiet and precise run on a thermoforming system is that the actuators work in the same direction and thus cancel their impulses at least largely. Whether the engines are Che have an opposite or a similar direction of rotation, is of little relevance to the product quality according to the findings of the inventor.

Thus, it is the proposal to use the drive units with the same direction of rotation. The drive units can then be manufactured in the previous type and used in a conventional manner. So here no new designs are required, and it can be used for example with standard motors in a vertical orientation.

[17] At the same time, the differently designed gears ensure that the actually decisive impulses essentially cancel each other out. [18] Preferably, the starting and braking torques of the two co-rotating drive units add up with respect to the thermoforming station. If the moments cancel each other exactly, the system runs as far as possible free from interference pulses.

[19] It has already been mentioned at the beginning that the drive unit pair provided with the same orientation and provided with counter-rotating actuating elements can be arranged to move the lower tool in a moving manner via two lower actuating elements.

Alternatively and cumulatively, it is possible for the two drive units to move the upper tool via two upper actuators.

[21] In a particularly preferred embodiment, a total of exactly two drive units or more and exactly four or more actuators or more are available. In such a constellation, each drive unit preferably attacks exactly one actuating element. For example, two drive units can act on two lower ends of a lower yoke on the lower tool. Both lower drive units preferably access exactly one eccentric shaft and, in each case, precisely one or two toggle levers via the eccentric shaft. The eccentric shaft and the toggle joint thus form a gear together and become here referred to as "actuator", wherein each of these two components as well as their entirety represents an "actuator".

[22] The drive units preferably have vertical axes of rotation.

[23] A drive unit with a vertical axis of rotation can be integrated into the thermoforming station to save space. As a result, the entire thermoforming station builds very small, allowing for a compact thermoforming system.

[24] In addition, the vertical arrangement of the drive units, especially when connected either at the top or at the bottom, helps to maintain and understand the installation. This is especially true when all drive units are driven in the same direction.

In a simple and very compact embodiment, two drive units are arranged at the same height on the thermoforming station, in particular two at two yokes, of which one yoke is provided for the upper and one for the lower tool. The upper and the lower tool are screwed back directly to the yoke, so the upper tool below the Oberjochs, corresponding to the lower tool above the lower yoke.

[26] Preferably, all drive units for the lower tool are arranged at a height, and / or all drive units for the upper tool are arranged at a height. [27] Particularly preferably, the drive units for the upper and the lower tool are arranged one above the other.

It has already been mentioned that the actuating elements can at least partly consist of an eccentric shaft. In this case, but also in others rotatory components for driving the mold, it seems promising when actuators have horizontal axes of rotation.

[29] When two drive units are arranged diagonally with respect to a stroke axis of the mold, it is particularly easy to prevent disturbing pulses to the thermoforming station.

[30] Ideally, the axes of rotation of two actuators for the lower and for the upper tool parallel to each other, in particular all parallel to each other. This allows a particularly compact design.

[31] Regardless of the presence of eccentric shafts, but suggested in addition thereto, it is proposed that the actuators have toggle levers.

[32] The drive units introduce torques and angular momentum, ie rotational movements. However, the mold itself must be guided at least largely linear. A part of the transmission is therefore necessary to convert the rotational movement of the drive units in the linear movement of the mold. For this toggle levers are very suitable.

In view of the fact that toggle levers in operation of the thermoforming system can be subjected to high pressure forces, the toggle levers are quite massive and therefore difficult to carry out. The greater is their harmful influence in the swinging of unwanted angular momentum into the thermoforming system.

[34] Thus, it is particularly appropriate, in implementation of the first aspect of the invention, to make a rotational movement of the toggle lever on the lower tool, the toggle lever on the upper tool or the toggle on the lower and upper tool in pairs or total in opposite directions, so cancel the pulses of the toggle , [35] The same applies to the eccentric shafts.

[36] The inventor has provided that the drive units for the upper and / or lower tool can be coupled via an electric shaft.

[37] An "electric wave" is understood to mean a fine control of the drive units in relation to each other.

[38] A second aspect of the invention proposes that a drive unit, in particular a motor-gear unit, can be arranged at several points along the actuating element.

[39] In this context, it should be explained conceptually that the "actuator" should be understood to mean, in particular, the assembly of the eccentric shaft and the toggle lever, whereas the "motor-gearbox unit" should be understood as the connection between the motor and the actuating element. The "transmission" is thus attributed to the engine rather than the actuator unit.

The second aspect of the invention can be realized in particular when drive units are arranged such that they protrude perpendicular to the axis of the eccentric shaft, in particular in a vertical arrangement. Thus, a drive unit can be connected to each eccentric shaft. The eccentric shafts as such, even if they are four pieces, can each be designed identically in principle, as well as the toggle lever. This leads to a high degree of rationalization in the production of the thermoforming station.

[41] The drive units can be connected to any position along each eccentric shaft. [42] According to a third aspect of the invention, the stated object solves a thermoforming station in which the upper tool and the lower tool have identical tables and / or yokes, which are merely arranged the other way around.

[43] In realizing this aspect, identical parts can be used. Only the shell mold itself must be shaped differently if the molded part requires it. All mechanically driving parts, however, can be reversed as required. This not only increases the degree of safety in the production of the machine parts, but also facilitates the storage of spare parts.

[44] A fourth aspect of the invention solves this problem by means of a thermoforming station having a forming tool with an upper and a lower tool and with a drive for the forming tool for moving in an opening and closing direction, the drive having two drive units which each have a direction of rotation during operation and act on the molding tool via an actuating element for movement of the molding tool, the actuating elements each having an actuating element rotation direction during operation, the moving upper and / or lower tool being mounted in a tumbling manner, in particular with one Vertical guide, which allows axial rotation.

The tumbling storage of upper tool, upper yoke, upper table, lower tool, lower yoke and / or undertable has proven in prototype experiments of the inventor to be very advantageous for the product to be produced: it can not be ruled out, for example control that not follow when moving lag errors , However, if the table, yoke or tool is stored in such a way that damaging lateral forces can not occur in the event of an uneven procedure, the thermoforming station runs with significantly higher operational reliability and production accuracy. [46] Preferably, a linear rotary unit is provided, which is arranged perpendicular to the stroke direction and preferably perpendicular to the feed direction of the material through the thermoforming station.

[47] If a linear rotary unit is provided, the table can always move along the actual axis of symmetry and rotate on its center line on its own axis. The rotation angle required for this purpose depends on the drive geometry, for example on the toggle joint geometry.

[48] At the same time errors and tolerances in the drive, so in particular in the toggle lever compensated. [49] According to a fifth aspect of the invention, the stated object solves a thermoforming station having a forming tool with an upper and a lower tool and with a drive for the forming tool for moving into an opening and a closed position, wherein the drive comprises two drive units which in operation each have a drive direction of rotation and act to move the mold via an actuating element on the mold, wherein the actuating elements each have a Betätigungselementdrehsinn in operation, wherein an upper yoke for the upper tool and a lower yoke for the lower tool are connected to each other via Oberjochstützen wherein a Oberjochstütze has an overload device. [50] There are usually four Oberjochstützen between the Oberjoch and the Unterjoch. Often these are simply vertical, round supports with full or hollow cross-section,

The Öberjoch rests on the Oberjochstützen. Together with the lower yoke, it forms the two static elements which ultimately drive the upper and lower tools and provide the necessary counterforce for the thermoforming process. [52] When the mold is open, the upper yoke supports are subject to pressure. During the thermoforming process, ie with the mold closed and with pressure applied between the two parts of the mold, the compressive force in the Oberjochstützen can be coated. If the drives drive the upper and lower tools against each other with a greater force than the upper tool can apply to its own weight, the Oberjochstützen are neutral or even loaded on train.

[53] The upper yoke supports must be designed for large forces. However, sometimes larger forces can occur during operation which then lead to damage to the system. For this purpose, the overload device is provided. It is a deliberate weak point in the force system between Oberjoch, Oberjochstütze and Unterjoch. The overload device fails before the Oberjochstütze, Oberjoch or Unterjoch are damaged.

[54] The overload device is thus to some extent a deliberate weak point, or a desired deformation point in the force system.

[55] The overload device may for example comprise a spring assembly, a shear pin and / or a compression sleeve.

[56] A "spring package" is understood to mean a plurality of springs, for example, an equal number of identical springs on each upper yoke support.The particular advantage with springs is that they are reversible within a relatively large overforce range, if the design is suitable, and thus not once the overload device is damaged.

[57] A "shear pin" is sheared off when excessive force is applied, for which there is a force threshold below the force threshold, which acts as a lateral force on the shear pen acts, it remains stable. Above the force threshold, the pen shears and allows idle.

[58] A "compression sleeve" fails linearly, ie on pressure, above a force threshold.

[59] A spring assembly and a compression sleeve can be arranged in particular in the lifting direction.

[60] A shear pin is preferably arranged to the stroke direction, but in any case at an angle to the stroke direction.

[61] The overload device may comprise a shutdown means, a logging means and / or quirks. [62] A "shut-off means" means a means which shuts off a part of the thermoforming plant or the entire thermoforming plant, in particular, the intention is to switch off movements.

[63] Thus, it is well conceivable that in the case of failure of the overload device, the switch-off is activated, so that, for example, the stroke in the mold is not carried out further, the feed to film is not carried out and / or all transport rollers are stopped.

[64] The cut-off means can be electronic or mechanical. An electronic function is, for example, when a sensor detects that the overload device has failed and has thus been activated. The electronics can then access the plant control and stop all movements.

[65] A logging means is designed in particular electronically. The logging means can in any case state that the overload device has been activated. Surprisingly, this is particularly advantageous when it comes to a versible activation of the overload device is, so for example, an activation of spring packs.

[66] If the system regularly or at least occasionally goes into an overload range, the mechanical stability of the system as a result of the spring assembly would have been maintained unimpaired.

[67] Also a sequential stop is conceivable. Thus, for example, an advantageous embodiment that the movement is stopped immediately on the mold, but the stations are braked in the machine direction before the thermoforming station only within a short time and then stopped to an immediate standstill and the associated pressure in the rest of the system avoid.

[68] A mechanical effect of the shut-off means can be imagined, for example, in that a fuse is pulled by mechanical force or that a necessary power transmission part is pulled out of the force flow in case of failure of the overload device. [69] However, if quality control proves that the products made using the thermoforming process do not meet the requirements, a log can be used to understand that an overload situation has occurred.

[70] On the basis of a log of the total forces or, for example, the forces only in the event of overload situations can also easily identify the troubleshooting of qualitatively insufficient products, for example, a quality variation in the processed film or in the processed sheet for the Over force is responsible.

[71] A "means of acknowledgment" may consist, in particular, of an operator manually pressing a button, inserting a key and turning a key Card or otherwise must identify and connect the control of the system must actively set in motion before the system continues to run. In particular, it can be provided that only operators of a higher hierarchical level can actuate the acknowledgment means. [72] In the event of a shutdown, this would ensure that a qualified technician can inspect the condition of the installation while it is resting. Only if it detects no errors, which may also include an immediate display or inspection of a log, the system is released for further movement.

[73] According to a sixth aspect of the present invention, the stated object solves a thermoforming station having a forming tool with an upper and an outer tool and a drive for the molding tool for moving in an opening and a closing direction, the drive having two drive units which in operation in each case have a drive direction of rotation and act on the molding tool via an actuating element in each case, the actuating elements each having an actuating element rotation direction, wherein an upper yoke for the upper tool and a lower yoke for the lower tool are connected to each other via Oberjochstützen, wherein - as throughout the present application - the term "via one actuator" does not preclude two drive units from acting together on an actuator, with a table guide being formed separately from the upper yoke supports t.

[74] According to this aspect of the invention, the upper yoke supports preferably do not assume any guiding function for the linear movement of the table stroke. Rather, the linear guide is left to the "table guide." As a result, the upper yoke supports are free of transverse forces, with the exception of those very small transverse forces which can be introduced into the upper yoke supports at the top and bottom. [75] Experiments by the inventor have shown that excellent product qualities can be achieved with such a task-based separation between supporting forces in upper yoke columns and executives in the table guide.

[76] The table guide may preferably be a linear guide, in particular on both sides of the molding tool.

[77] In a preferred embodiment, disk-shaped or rod-shaped elements for the table guide can be provided on the upper yoke and on the lower yoke. The table guides for the upper table and for the lower table can preferably be designed identically, either integrally connected to the upper yoke or lower yoke or releasably secured there. This also increases the ease of maintenance and reduces the necessary inventory for maintenance.

[78] Motors can be used as drive units. In particular, it is intended to electric motors with a vertical axis in the installed state.

[79] One or more drive units can be designed as a motor. For example, all drive units are designed as a motor.

[80] A very advantageous constellation also results when a drive unit is made passive and is connected via a drive means to a motor arranged otherwise for driving the drive unit. In such an embodiment, not all drive units are provided as independent motors; Rather, at least one drive unit is passively formed. A "passive drive unit" is understood as meaning such a drive unit which has to be driven rearwardly via a drive means in order to act with its output on the actuating element.

[81] The drive means are in particular belts or chains into consideration. [82] In a very simple embodiment, a motor is connected via a belt or chain drive with one or more passive drive units, wherein the. passive drive units are arranged directly on the machine frame, specifically at the thermoforming station, so that the passive drive units act on their output to the actuators.

[83] Within the belt or chain drive, several deflections are preferably provided.

[84] A motor and passive drive units driven by it may be made to rotate in the same direction with respect to their engine or drive unit rotational sense. In particular, it should be remembered that all motors and all passive drive units of the same thermoforming station have a same direction of rotation.

[85] It is understood that the above features and their advantages can be found either individually or cumulatively on a thermoforming station.

[86] Moreover, it is clear that the benefits of the improved thermoforming station have an immediate effect on the entire multi-station thermoforming system for processing transparencies or sheets.

[87] In terms of the method, it is proposed that a thermoforming station be used as described above for producing intermediates or finished articles from films or sheets on a thermoforming machine. [88] Finally, it is understood that the advantageous properties of the thermoforming system itself extend to an article made therewith. In the long term, this can be produced more precisely than with conventional systems.

[89] The invention will be explained below with reference to some embodiments with reference to the drawing. Show there Figure 1 shows a schematic view of two vertically arranged motors with

Gear, eccentric shaft and two toggle levers,

2 shows the arrangement of Figure 1 in a plan view,

FIG. 3 shows an alternative arrangement to FIG. 1 in a view,

FIG. 4 shows the alternative arrangement from FIG. 3 in plan view,

FIG. 5 shows a schematic top view of a first motor arrangement,

FIG. 5a shows the first motor arrangement from FIG. 5 in a view,

FIG. 6 is a schematic plan view of a second motor arrangement;

6a, the second motor assembly of Figure 6 in view,

FIG. 7 is a schematic plan view of a third motor arrangement;

7a, the third motor assembly of Figure 7 in view, wherein the motor assemblies of Figures 5, 6 and 7 may also be mirror-inverted in view, so with vertically upstanding motors,

8 is a schematic view of a thermoforming station with a staggered lifting table, FIG.

9 shows the thermoforming station from FIG. 8 with deflected upper table and undeflected lower table, FIG.

FIG. 10 shows, in a schematic partial view, an upper yoke supported on a top yoke with an upper table arranged thereon, driven into a closed position, and with a spring assembly,

Figure 11 is a schematic plan view of a fourth engine assembly and

FIG. 12 shows the fourth motor arrangement from FIG. 11 in a view.

[90] A drive 1 for a lower table of a thermoforming station consists essentially of a first motor 2, a second motor 3, associated transmission housings 4 (identified by way of example), a lower yoke 5 and a first toggle lever 6 and a second toggle lever 7 , With reference to a machine direction 8 (cf. FIG. 2), the two motors 2, 3 are arranged point-symmetrically about a center of the thermoforming station.

In operation, the first motor 2 drives a first eccentric shaft 9. At the same time, the second motor 3 drives a second eccentric shaft 10. As a result, the total of four toggle levers 6, 7 (identified by way of example) are moved up and down with respect to a stroke direction 11, that is to say along the vertical.

[93] In the upper position, the press is closed at the thermoforming station. In the lower position, the press is open at the thermoforming station.

[94] The two motors 2, 3 run with a first drive rotation 12 or with a second drive rotation 13.

Both drive rotational direction 12, 13 are the same orientation, ie in the plan view of Hubrichrung 11 in the clockwise direction.

[96] The driven eccentric shafts 9, 10 run simultaneously with a first actuating element rotational direction 14 and a second actuating element rotational direction 15. In the horizontal direction according to FIG. 1, these two actuating element rotational channels 14, 15 are oriented oppositely. The first actuator rotation direction 14 runs counterclockwise. By contrast, the second Betätigungselementdrehsinn 15 runs in a clockwise direction.

[97] The situation is analogous with the two toggle levers 6, 7. [98] In operation, the torques and angular momentum of the two motors 2, 3 are therefore added to the total drive 1 and thus to the entire thermoforming system. However, these influences are negligible.

On the other hand, cancel the torques and angular momenta of the actuators, ie the two eccentric shafts 9, 10 and the total of four toggle lever 6, 7 on. Since these elements rotate at high mass and speed, these are the critical influences on the system.

[100] The two motors 2, 3 are arranged vertically. Conventional motors can be used. The direction of rotation is identical. This allows a very light construction of the system.

[101] The alternative drive 16 in FIGS. 3 and 4 differs from the drive I described first only in that two motors 17, 18 both run counterclockwise in plan view, ie exactly the opposite to the two motors 2, 3 on the first drive 1. However, the eccentric shafts and toggle arms run exactly as in the first drive from FIGS. 1 and 2 via correspondingly redesigned transmissions.

The first motor arrangement 19 in FIGS. 5 and 5 a shows, just like the second motor arrangement 20 and the third motor arrangement 21, by way of example a top yoke 22 for driving an upper table 23.

[103] It is understood that the same representation can likewise show the drive of a substation on a lower yoke in an analogous manner.

[104] In the first motor arrangement 19, two motors 24, 25 are arranged between two toggle lever arrangements on an eccentric shaft.

[105] In the second motor assembly 20, both motors 24, 25 are located on one side adjacent to the two toggle lever drives. [106] Finally, in the third motor arrangement, the two motors 24, 25 are diagonally opposite each other, each on one side of the two toggle lever drives.

[107] The motor gear unit can be moved arbitrarily along the eccentric axes. This allows a high degree of design freedom in the drives. The motors are driven, for example, via an electric shaft, in which the motors are coupled via a common master.

[109] The thermoforming station is symmetrical between top and bottom. In particular, mirror-inverted or rotated by 180 ° arrangements crowd. [110] The thermoforming station 26 in FIGS. 8 and 9 initially has a lower yoke 28 on a floor 27. On this four Oberjochstützen 29 (identified by way of example) are arranged, which extend vertically upwards and at its upper end a Oberjoch 30 support.

On the lower yoke 28 there are a total of four toggle lever drives 31 (identified by way of example). If these are set in rotation, for example by a motor, gear and eccentric shaft arrangement as shown in FIGS. 1 to 7a, then a lower table 32 rises and falls.

[112] The same applies analogously to an upper table 33.

The lower table 32 and the upper table 33 are mounted on a lower table guide 34 and an upper table guide 35 vertically longitudinally displaceable. Both the lower table guide 34 and the upper table guide 35 each have guide elements, "for example, rails which are fastened or supported or guided on the lower yoke 22 and on the upper yoke 33.

[114] The lower table guide 34 and the upper table guide 35 serve as a linear guide for the two tables.

At the same time, the undertable 32 and the top table 33 are staggering. At each table, a linear rotary unit 36 (indicated by way of example) is provided. Around a bearing shaft 37 (identified by way of example), the two tables are movable along a wobble play degree of freedom 38 (identified by way of example), so that the tables can assume an angle 40 relative to a perpendicular to the stroke direction 39, that is to say the vertical.

[1 16] On the control side, following errors can not be excluded. Due to the mounting of the two tables, no destructive transverse forces can occur even with an uneven process of the toggle lever drives 31.

[117] As a result, both the lower table 32 and the upper table 33 always move along their axes of symmetry and can rotate about their own axis on this center line. At the same time errors and tolerances in the toggle lever drives 31 are compensated. [118] During operation of the thermoforming station, high vertical forces are exerted on the top table 41 by the press. These are transmitted via a knee lever 42 on the upper yoke 43. This is connected via the Oberjochstütze 44 with an anchorage 45, which may for example be a lower yoke.

[119] At the junction between the Oberjochstütze 44 and the Oberjoch 43 a biased spring assembly 46 is provided.

[120] As long as a small vertical force 47 acts on the upper table 41, the prestressing of the spring assembly 46 overruns the vertical force arriving at the upper yoke 43 from the toggle lever 42. Because the Oberjochstütze 44 is fixedly mounted on the anchor 45, the bias in the spring assembly 46 acts on the Oberjoch 42 down. The small vertical force 47 counteracts upward, but is suppressed by the bias in the spring assembly 46.

[121] When the biasing force in the spring pack 46 is set to have a critical or allowable load, the spring pack 46 becomes a compressed spring pack 46 precisely when an excessive force 49 acts vertically upward on the upper stage 41. Because this force is also on the toggle 42 on the Oberjoch 43 transferred. The upward force is thus greater than the biasing force from the spring assembly 46. The spring assembly 46 then upsets, with increasing spring travel 50, the vertically downwardly acting spring force of the compressed spring assembly 48 increases linearly. As a result, the spring assembly 46 so only to a sprained spring assembly 48, but it will not penetrate out of the elastic range addition.

[122] The upper support 44 preferably does not assume any guiding function of the table support, but leaves this to a separately provided table guide.

In this way, it is ensured that at the upper yoke actually only vertical forces arrive, which correspond exactly to the press forces.

[124] If an undesired force peak occurs here, this is absorbed in the compensating elements, specifically in the spring assembly 46.

In the Oberjochstütze 44 and / or on the toggle lever 42 and / or on the connection of toggle 42 and / or Oberjochstütze 44 to the upper yoke 43 and / or in the spring assembly 46 force transducer may be provided which record the flow of forces.

[126] In case of overload, the drive is switched off. Only after entering a release code, the system can be put back into operation.

It is understood that in the above embodiments, the motors may also be replaced by other drive elements. In particular, it is intended to passive drive elements, which are driven by one or more otherwise arranged motors together or individually and abort in turn to transmissions or directly to actuators.

[128] The fourth motor arrangement 51 in FIGS. 11 and 12 differs from the previous motor arrangements in particular in that two passive drive elements 52, 53 and an active motor 54 are provided at the thermoforming station.

The two passive drive elements 52, 53 are each formed with a vertical axis of rotation as a rotatable round body and each arranged on an eccentric shaft 55 (exemplified) and connected to this via a gear 56 (exemplified) connected.

The motor has a round drive body 57 in the form of a disc with a vertical axis of rotation. The two passive drive elements 52, 53 each have a round rotary body 58, 59. The two Rotati onskörper 58, 59 also have a vertical axis of rotation. They are connected to the drive body 57 via a drive belt 60. The drive belt 60 also runs between the motor 54 and the two passive drive elements 52, 53 via two deflection rollers 61 (identified by way of example), which likewise have a vertical axis.

[131] The rotation of motor 54, passive drive elements 52, 53, drive body 57 and rotation bodies 58, 59 are fixedly coupled to each other via the single-circulation drive belt 60. When the motor 54 forces a rotation on the drive body 57 during operation, this rotation is transferred to the two passive drive elements 52, 53. The diameter ratio between the drive body 57 and the two rotation bodies 58, 59 can be used to convert the rotatio onsgeschwindigkeit starting from the motor 54 cause. The two Rotati onskörper 58, 59 preferably have the same diameter.

[132] In this way, the rotating motor 54 ensures that the two passive drive elements 52, 53 exert rectified acceleration and braking torques on the thermoforming station. These even add up to the drive and braking torques of the motor 54, if such is connected to the same machine frame of the thermoforming station. [133] Via the two gears 56, the synchronous driving directions of rotation of the passive drive elements 52, 53 are translated into opposite rotations of the eccentric shafts 55. The moments of the eccentric shafts 55 cancel each other out.

[134] The motor 54 is arranged on the central axis of the thermoforming station in the example shown. It is understood, however, that the engine can be arranged completely freely. In particular, it is even possible to drive with an engine, the passive drive elements of several stations on the thermoforming system, especially when clutches are provided, the acceleration and braking torques when coupling and decoupling and are problematic for the product quality, because the moments of the actuators cancel.

LIST OF REFERENCE NUMBERS

Drive 32 under table

first motor 33 upper table

second motor 34 lower table guide

Gear housing 35 upper table guide

Unterjoch 36 linear rotary unit first toggle lever 37 bearing shaft

second toggle lever 38 wobble clearance degree

Machine direction 39 Lift direction

first eccentric shaft 40 angle

0 second eccentric shaft 41 upper table

1 stroke direction 42 toggle lever

2 first drive direction of rotation 43 Oberjoch

3 second drive rotation 44 upper yoke support

4 first actuator rotation 45 anchoring

5 second actuator rotation 46 spring pack

6 alternative drive 47 small vertical force7 motor 48 compressed spring package8 motor 49 excessive force

9 first motor assembly 50 spring travel

0 second motor arrangement 51 fourth motor arrangement 1 third motor arrangement 52 passive drive element 2 upper yoke 53 passive drive element 3 upper table 54 motor

4 engine 55 eccentric shaft

5 engine 56 gearbox

6 Thermoforming station 57 Drive body

7 floor 58 rotation body

8 lower yoke 59 rotation body

9 Oberjoch support 60 drive belts

0 Oberjoch 61 pulleys

1 toggle lever drive

Claims

claims:

1. thermoforming station with a mold with an upper and a lower tool and with a drive for the mold for moving in an opening and in a closing direction, wherein the drive has two drive units which each have a drive rotation in operation and for moving the mold act in each case via an actuating element on the mold, wherein the actuating elements in each case during operation have a Betätigungselementdrehsinn, characterized in that two drive units for the mold

• with corotating drive direction of rotation

• are arranged via transmission for driving the actuators with opposite Betätigungselementdrehsinn.

2. thermoforming station according to claim 1, characterized in that add start-up and braking torques of the two co-rotating drive units with respect to the thermoforming station.

3. thermoforming station according to claim 1 or 2, characterized in that the two drive units via two lower actuating elements move the lower tool.

4. thermoforming station according to one of the preceding claims, characterized marked characterized in that the two drive units via two upper actuating elements move the upper tool.

Thermoforming station according to one of the preceding claims, characterized in that there are four drive units and four actuating elements, in particular exactly four,

Thermoforming station according to one of the preceding claims, characterized in that the drive units have vertical axes of rotation.

Thermoforming station according to one of the preceding claims, characterized in that two drive units are arranged at the same height at the thermoforming station, in particular in each case two at two yokes for the lower and for the upper tool.

Thermoforming station according to one of the preceding claims, characterized in that two drive units with respect to a lifting axis of the mold are arranged diagonally to each other.

Thermoforming station according to one of the preceding claims, characterized in that the actuating elements have horizontal axes of rotation.

Thermoforming station according to one of the preceding claims, characterized in that the actuating elements have eccentric shafts.

Thermoforming station according to one of the preceding claims, characterized in that the actuating elements have toggle levers.

Thermoforming station according to one of the preceding claims, characterized in that the drive units for the upper and / or lower tool are coupled via an electric shaft.

Thermoforming station comprising a forming tool with an upper and a lower tool and with a drive for the forming tool for moving in an opening and in a closing direction, wherein the drive has two drive units having units which in operation each have a drive direction of rotation and act to move the mold via an actuating element on the mold, wherein the actuating elements each have an operating element rotation in operation, in particular according to one of the preceding claims, characterized in that a drive unit at several points can be arranged along the actuating element.

Thermoforming station with a molding tool with an upper and a lower tool and with a drive for the molding tool for moving in an opening and closing direction, wherein the drive has two drive units which each have a drive rotational direction during operation and for moving the mold over each an actuating element acting on the mold, wherein the actuating elements in operation each have a Betätigungselementdrehsinn, in particular according to one or more of the preceding claims, characterized in that the upper and the lower tool have identical tables and / or yokes, which are arranged the other way around.

Thermoforming station with a molding tool with an upper and a lower tool and with a drive for the molding tool for moving in an opening and closing direction, wherein the drive has two drive units which each have a drive rotational direction during operation and for moving the mold over each an actuating element acting on the mold, wherein the actuating elements in operation each have a Betätigungselementdrehsinn, in particular according to one or more of the preceding claims, characterized in that the moving upper and / or lower tool is mounted wobbling, in particular with an axial rotation permitting storage on a vertical guide.

Thermoforming station with a molding tool with an upper and a lower tool and with a drive for the molding tool for moving in an opening and closing direction, wherein the drive has two drive units which each have a drive rotational direction during operation and for moving the mold over each an actuating element acting on the mold, wherein the actuating elements in operation each having a Betätigungselementdrehsinn, wherein an upper yoke for the upper tool and a lower yoke for the lower tool are connected to each other via Oberjochstützen, in particular according to one or more of the preceding claims, characterized in that a yoke support having an overload device.

Thermoforming station according to claim 16, characterized in that the overload device comprises a spring assembly, a shear pin and / or a compression sleeve.

Thermoforming station according to claim 16 or 17, characterized in that the overload device has a shutdown, a logging and / or a Quittiermitte], wherein in particular after a shutdown a reclosure can only be done after an authentication.

19. thermoforming station with a mold with an upper and a lower tool and with a drive for the molding tool for moving in an opening and in a closing direction, wherein the drive has two drive units, which each have a drive rotation in operation and for moving the mold via an actuating element in each case acting on the mold, wherein the actuating elements in operation each have a Betätigungselementdrehsinn, wherein an upper yoke for the upper tool and a lower yoke for the lower tool are connected to each other via Jochstützen, in particular according to one or more of the above Claims, characterized in that a table guide is formed separately from the Jochstützen.

Thermoforming station according to one of the preceding claims, characterized in that a drive unit is designed as a motor, in particular all drive units are designed as motors.

Thermoforming station according to one of the preceding claims, characterized in that a drive unit is configured passively and is connected via a drive means with a motor arranged otherwise for driving the drive unit.

Thermoforming station according to claim 21, characterized in that the drive means comprises a belt or chain drive.

Thermoforming station according to one of claims 21 or 22, characterized in that a motor with a plurality of passive drive units by means of one or more drive means is drivingly connected.

Thermoforming station according to claim 23, characterized in that the motor and driven by him passive drive units with respect to their Motorbzw. Drive unit rotation direction are arranged in the same direction rotating.

A multi-station thermoforming machine for processing sheets or plates, comprising a thermoforming station according to one or more of the preceding claims.

A method of forming and / or stamping articles from sheets or plates, using a thermoforming machine according to claim 25 and or a thermoforming station according to one or more of claims 1 to 24.

Article produced by a method according to claim 26.