EP3678940B1 - Working station with a lifting mechanism for a packaging machine - Google Patents

Description

The invention relates to a work station, in particular a deep-drawing station, forming station, sealing station, cutting station or punching station, for a packaging machine, with a frame supported on the floor, a work unit comprising an upper part and a lower part, and a lifting mechanism carried by the frame, with which the lower part the working unit can be raised and lowered relative to the frame to carry out a sub-stroke, the lifting mechanism having a drive which has at least one shaft extending in the transverse direction, a drive motor acting on the shaft for rotating the shaft and at least one coupled to the shaft on the input side Gear includes, on which the lower part is supported on the output side and which converts a rotation of the shaft into the lower stroke of the lower part.

Such workstations are generally known (e.g. from DE 103 51 567 A1 ) and are used in particular on packaging machines where the packaging is made from film webs. In this case, depressions are first made in a bottom film in a deep-drawing or molding process, then objects to be packaged, such as food products, are inserted into the depressions, then the depressions are closed by sealing with a top film, and then the individual packs are separated by cutting or punching out.

At least at some work stations of the packaging machine it is necessary to raise and lower the tools used for the respective work process. A deep-drawing station, for example, has a working chamber formed from an upper chamber part and a lower chamber part which in the open state the film web can be conveyed through and in which in the closed state the mentioned depressions are produced by applying negative pressure to the film web from the lower chamber and with compressed air via the upper chamber. To close the chamber, the two chamber parts must be pressed together. In addition, high additional forces act on the chamber parts during the deep-drawing process due to the pressurization on a relatively large area. Consequently, the lifting mechanism provided for opening and closing the chamber, the frame carrying the lifting mechanism and the devices for supporting the lifting mechanism on the frame are in practice exposed to considerable loads, which can correspond to a weight of several tons.

Known work stations for packaging machines are therefore designed to be massive and are provided with correspondingly powerful, large motor drives and lifting mechanisms to carry out the lifting movement. Such workstations are therefore large, heavy and expensive. Furthermore, some of these work stations are only designed specifically for an assigned tool or packing format, so that there is constant maintenance work depending on the structure and use of components.

In addition, in practice it is necessary at some work stations not only to raise and lower the lower part of the respective work unit, but also to carry out a so-called upper lift in addition to this lower lift, that is, to also raise and lower the upper part of the work unit. At a deep-drawing station, for example, it should be ensured that heating devices integrated into the upper chamber for heating the film web do not act on the film web too early before the actual deep-drawing process, but that the heat only begins when the chamber is closed or at the start of the closing process. The upper lift function leads to an even more complex structure of the known workstations. In particular, additional drives are used for this purpose used. But even without upper stroke functionality, some known work stations already have a large number of movable elements and a number of drives that have to be synchronized in a complex manner to carry out the lower stroke.

Well-known work stations for packaging machines are, for example, in EP 1 118 540 B1 , DE 103 51 567 B4 , DE 10 2004 006 118 A1 , DE 10 2008 019 626 A1 , DE 10 2015 211 622 A1 and EP 2 666 727 B1 described.

The object of the invention is to create a work station of the type mentioned at the beginning, which has a powerful and highly resilient lifting mechanism with a simple and space-saving structure.

This task is solved through the independent claims.

According to the invention it is provided that the shaft is supported on the frame and carries a base of the lifting mechanism, in which the shaft is rotatably mounted and on which the upper part is supported, the shaft of the lifting mechanism having several support members, in particular rollers or shafts, supported on the frame and the lifting mechanism is adjustable, in particular movable, in the longitudinal direction relative to the frame by means of the support members.

This concept advantageously makes it possible to absorb the forces that occur during the work process, for example when closing the chamber of a deep-drawing station, within the lifting mechanism without influencing the frame. The support of the lifting mechanism on the frame therefore only needs to introduce the weight of the lifting mechanism into the frame, but not the process forces acting within the lifting mechanism when executing the lower stroke and during the lifting of the lower part, in a deep-drawing station, i.e. with the working chamber closed.

In relation to a possible practical embodiment, this means, for example, that the support of the lifting mechanism on the frame only has to be designed for a weight force of a few 100 kg, whereas process forces that correspond to a weight force of more than 10 t are effective within the lifting mechanism.

According to the invention, the lifting mechanism therefore forms a mechanically independent and self-contained unit in terms of functionality and with regard to the process forces effective during operation, which only needs to be carried by the frame of the work station.

Advantageous embodiments of the invention are given below and also result from the claims and the figures as well as the associated description of the figures.

The base, which is supported by the shaft supported on the frame, may comprise a frame. Such a frame, which has, for example, a rectangular box structure with two longitudinal beams and two cross beams, can ensure a particularly high stability of the lifting mechanism. The interior of this stability frame is particularly available for moving parts of the lifting mechanism.

The gear provided between the shaft and the lower part is preferably designed as a coupling gear, in particular as a slider crank gear. It is preferably a centric slider crank mechanism.

The gear between the shaft and the lower part can include a toggle lever arrangement. In particular, the toggle lever arrangement is in a position with the lower part raised to the maximum, which in particular is a closed working unit corresponds, stretched. This can ensure that no torque is exerted on the shaft by the lower part under maximum load due to the process forces. This position of the transmission is also referred to below as the extended position or the neutral position.

The gear between the shaft and the lower part can comprise at least one pair of congruent and spaced-apart push rods, between which a shaft crank connected in a rotationally fixed manner to the shaft is articulated on the input side and the lower part or a carrier for the lower part is articulated on the output side.

Such a symmetrical structure prevents the creation of disruptive tilting moments. Measures to absorb or store or dissipate corresponding transverse forces can therefore be omitted.

Preferably, the shaft is rotatably mounted in longitudinal supports of the base that are spaced apart from one another in the transverse direction. As a result, the shaft can support the base in a particularly simple structural manner and can also increase the stability of the base due to the cross connection between the longitudinal beams formed by the shaft.

The transmission preferably comprises at least two individual transmissions spaced apart along the shaft and synchronized by means of the shaft for joint execution of the lower stroke. Consequently, a shaft can engage the lower part via a gear at several points spaced apart in the transverse direction. This further increases stability and ensures that the process forces effective during operation are distributed.

The lifting mechanism preferably comprises a plurality of synchronized shafts spaced apart along the frame, each with a gear for carrying out the lower stroke together. Multiple waves in turn increase the stability of the Lifting mechanism, as it can be attacked at points on the lower part that are spaced apart in the longitudinal direction. The number of shafts can basically be chosen arbitrarily, in particular to adapt the lifting mechanism to the required overall length of the work station.

Multiple shafts are particularly advantageous in combination with the previously explained embodiment, according to which the gear in question is divided into at least two individual gears spaced apart along the shaft on each shaft.

Preferably, two synchronized individual gears are provided per shaft, which are arranged in the area of the outer sides of the lifting mechanism, i.e. each shaft engages on the lower part with a left-hand individual gear and a right-hand individual gear - seen, for example, in the conveying direction of a film web running through the work station. The space between the two individual gears can then be used for other purposes.

A particularly precise movement sequence of the lower part relative to the upper part can be achieved in particular in that, according to a further embodiment, the lower part is guided on the base, on the upper part or on a column supporting the upper part on the base during the lower stroke. To further increase the stability of the lifting mechanism, it can be provided that the column stands directly above the shaft, i.e. the column is supported on the base in such a way that a vertical central axis of the column intersects the axis of rotation of the shaft.

According to a preferred structure of the transmission explained above, a left and a right column can be provided for a respective shaft, so that the upper part in the area of this shaft is supported at two points spaced apart in the transverse direction on the base and thus on the shaft carrying the base.

The arrangement of columns directly above the shafts advantageously ensures that the weight of the upper part is transferred directly into the shaft and thus into the frame.

The upper part can be supported on the base in an adjustable height. As a result, the position of the upper part can be adjusted, for example, relative to a film plane, i.e. to the plane which is defined by a film web running through the work station and is therefore determined externally, i.e. not by the work station, but by the packaging machine into which the work station is located is integrated.

Several columns supporting the upper part on the base can simultaneously serve to adjust the position of the upper part if, according to a further exemplary embodiment of the invention, the columns or their supports on the base are designed to be height-adjustable.

According to a further exemplary embodiment, the drive motor engages the shaft via a coupling gear. This coupling gear is not to be understood as meaning the motor gear having the drive shaft of the motor as an input member, but rather a coupling gear that includes an output member, for example a motor crank, which can be set in rotation by means of the drive motor and interacts with the shaft via the coupling gear.

In a preferred embodiment of the invention it is provided that in a position with the lower part being maximally lowered, which corresponds in particular to an open working unit, the torque applied to a drive shaft of the drive motor via the coupling gear is zero or approximately zero. As a result, the drive motor does not need to apply any holding torque when the lower part is lowered to the maximum, so that, for example, the drive motor can be easily replaced in this situation.

In a preferred embodiment, the coupling gear is designed as a four-bar linkage, which comprises a drive shaft of the drive motor, a motor crank connected to the drive shaft, a drive coupling articulated to the motor crank and a shaft crank connected in a rotationally fixed manner to the shaft and articulated to the drive coupling. In particular, a motor gear is provided between the drive shaft of the motor and the motor crank, which will not be discussed in more detail here.

The arrangement of such a four-bar linkage between the drive motor and the shaft enables, in particular, an advantageous interaction with the gear between the shaft and the lower part if the two gears are coordinated accordingly. This will be discussed in more detail elsewhere.

In a preferred embodiment of the invention it is provided that in a position with the lower part being lowered to the maximum, which corresponds in particular to an open working unit, the axis of rotation of the drive shaft of the drive motor, the joint axis between the motor crank and the drive coupling and the joint axis between the drive coupling and the shaft crank are at least approximately in one plane lay. This position of the coupling gear is also referred to below as the extended position or the neutral position. An advantage of this position is that no torque acting in the sense of a further lowering of the lower part can be applied to the drive shaft of the motor via the shaft, which means the possibility of easy interchangeability of the motor, already mentioned above.

The drive motor is preferably an electric motor, in particular a servo motor. Alternatively, a pneumatic or hydraulic drive can also be provided.

According to a further exemplary embodiment of the invention, the base can be lowered and raised relative to the frame in order to carry out an upper stroke of the upper part. This allows the lifting mechanism to be provided with an integrated upper lift function. Possible configurations of the lifting mechanism to implement this upper lift function will be discussed in more detail elsewhere.

Preferably, the lower stroke and the upper stroke are positively coupled to one another. As a result, the lower stroke movement and the upper stroke movement can advantageously support each other. This forced coupling preferably takes place through the shaft.

It is preferably provided that the lower stroke and the upper stroke run in opposite directions to one another.

According to the invention, it is provided that the lifting mechanism is adjustable in the longitudinal direction relative to the frame. As a result, the work station can be adapted in a very simple manner to different applications in the operation of the packaging machine, in particular to different format sets, i.e. arrangements of a predetermined number of packages relative to one another, or to the timing of the packaging machine.

An adjustability of the lifting mechanism as a whole relative to the frame results in particular from the fact that the lifting mechanism represents a self-contained unit that is only supported on the frame via one or more shafts. This makes it possible, according to a preferred embodiment of the invention, to design the lifting mechanism in the manner of a carriage or carriage, which can be moved or moved as a whole on the frame to be brought into the desired position within the work station and consequently within the respective packaging machine.

According to the invention it is provided that the lifting mechanism is supported on the frame via several support members, in particular rollers or shafts, and is adjustable, in particular movable, in the longitudinal direction relative to the frame by means of the support members.

The frame can have at least two support profiles running parallel and spaced apart in the longitudinal direction, on which the lifting mechanism is supported and along which the lifting mechanism is adjustable relative to the frame.

In particular, the lifting mechanism and frame can work together as a wheel/rail system with regard to adjustability in the longitudinal direction. For lateral guidance of the lifting mechanism on the frame, the support members, which are preferably designed as rollers, can each be provided with a recess or a step.

According to a further exemplary embodiment, a fixing device can be provided, by means of which the position of the lifting mechanism in the longitudinal direction on the frame can be fixed. The fixing device can include a spindle drive for adjusting the longitudinal position of the lifting mechanism. The spindle drive can comprise a spindle attached to the frame and a spindle nut, the spindle nut preventing movement of the lifting mechanism relative to the frame in the longitudinal direction and allowing it in the lifting direction.

The spindle nut can, for example, be connected in a longitudinally displaceable manner to a column supporting the upper part on the base in order to enable an upper stroke movement of the upper part.

According to one embodiment of the invention, the lifting mechanism comprises a plurality of synchronized shafts spaced apart along the frame, each with a gear for jointly carrying out the lower stroke.

By providing several shafts, the lifting mechanism can act on the lower part at points spaced apart in the longitudinal direction. This increases stability and ensures precise alignment of the lower part relative to the upper part.

Preferably, exactly one drive motor is provided for synchronous rotation of the shafts. This simplifies the construction of the lifting mechanism and reduces costs.

The drive motor is preferably arranged longitudinally outside each pair of shafts. This has the advantage that the drive motor does not get in the way of the moving parts of the lifting mechanism. The space between the waves can therefore be used for other purposes.

Preferably, the drive motor or an axis of rotation of a drive shaft of the drive motor lies at least approximately in a plane defined by the axes of rotation of the shafts. Installation space above or below this plane defined by the shafts is therefore not required for the drive motor.

According to one embodiment of the invention it is provided that the shafts are supported on the frame and together carry a base, preferably comprising a frame, on which the upper part is supported, the drive motor being arranged outside the base. By arranging the drive motor outside the base, the interior of the base is available for other purposes, for example for electrical, pneumatic or hydraulic lines in connection with the function of the tool used in the work station. In particular, when designing the moving parts of the Lifting mechanism and its kinematics of the drive motor itself are not taken into account.

The drive motor is preferably supported on a cross member of the base.

Furthermore, it is preferably provided that the drive motor is arranged such that a drive shaft of the drive motor runs parallel to the shafts. This facilitates the coupling between the drive motor and the shaft. In particular, an angular gear for the drive motor can be dispensed with.

Preferably the waves are mechanically synchronized.

The shafts are preferably rotatable in the same direction. This enables a particularly simple structure and a space-saving arrangement of the moving parts for synchronous rotation of the shafts.

According to one embodiment of the invention, the shafts are connected to one another by at least one synchronization coupling. In particular, it is provided that the drive motor acts on one of the shafts via a coupling gear and on the or any other shaft via the synchronization coupling coupled to the coupling gear. If more than two waves are provided, either a single synchronization coupling that connects all waves to one another can be provided. Alternatively, several synchronization couplings connected in series can be provided. This has the advantage that the synchronization couplings can act on the shafts at different transverse positions. This allows the structure of the lifting mechanism to be made more flexible.

According to one embodiment, it is provided that the synchronization coupling engages the shafts via a shaft crank connected to the shaft in a rotationally fixed manner.

According to one embodiment of the invention it is provided that the drive motor engages the shaft via a gear.

As already mentioned above, by providing a gear between the drive motor and the shaft, this gear can be coordinated with the gear between the shaft and the lower part with regard to the respective circumstances. This not only affects the situations explained in more detail below with the lower part raised to the maximum and the lower part lowered to the maximum, but also the sequence of movements and the course of the forces and torques when executing the lifting movement between the two extreme positions mentioned.

In particular, the structure of the gears and the arrangement of the moving parts within the lifting mechanism and thus within the work station on the one hand and the torque curve on the other hand can be coordinated with one another in such a way that a relatively small drive motor with comparatively low power is sufficient to carry out the required lifting movement, and the Moving parts of the lifting mechanism require little space.

With regard to possible configurations of the transmission provided between the drive motor and shaft, reference is made to the above statements.

In a preferred embodiment, it is provided that the gear between the lower part and the shaft and the gear between the drive motor and the shaft are designed and coordinated with one another in such a way that when raised to the maximum Lower part and when the lower part is maximally lowered, one of the gears assumes a neutral position.

In particular, when the lower part is raised to the maximum, the torque applied to the shaft by the lower part is zero or approximately zero. This can be achieved, for example, by a toggle lever arrangement of the transmission between the shaft and the lower part that is stretched in this position.

Furthermore, it can be provided in particular that when the lower part is lowered to the maximum, the torque applied by the lower part to a drive shaft of the drive motor is zero or approximately zero. As already mentioned elsewhere, this can be achieved, for example, by a stretched configuration of a four-bar linkage forming the transmission between the drive motor and the shaft.

A shaft crank connected to the shaft in a rotationally fixed manner can be provided as a common element and in particular as the only common element of the two transmissions.

Furthermore, a preferred embodiment provides that when the maximum stroke of the lower part is carried out, a motor crank connected to the drive motor rotates through a larger angle than the shaft. In particular, the angle of rotation of the motor crank can be larger by approximately 20 to 70%, in particular by approximately 40 to 60%, than the angle of rotation of the shaft.

In a practical embodiment, the maximum stroke of the lower part corresponds to a rotation of the shaft by approximately 80° to 120°, in particular by approximately 100°.

Furthermore, it can be provided that the maximum stroke path of the lower part corresponds to a rotation of a motor crank connected to the drive motor by approximately 140° to 160°, in particular by approximately 150°.

According to one embodiment of the invention, it is provided that the upper part can be lowered and raised relative to the frame to carry out an upper stroke.

As already mentioned at the beginning, for some applications it is necessary that not only the lower part of the working unit can carry out a lower stroke, but also the upper part can be lowered and raised relative to the frame.

A particularly advantageous possibility for carrying out an upper stroke results from a structure of the lifting mechanism and a way of supporting the lifting mechanism on the frame, as explained above in connection with the invention. The possibility of executing an upper stroke is not mandatory with such a concept, but can be implemented in a simple manner in order to integrate an upper stroke function into the lifting mechanism.

Accordingly, the upper part is supported on the frame via the shaft.

A preferred way of integrating an upper lift function into the lifting mechanism provides that the shaft is mounted eccentrically on the frame with respect to its axis of rotation. A rotation of the shaft about its axis of rotation consequently results in a movement of the axis of rotation relative to the frame with a vertical component. This movement of the shaft can be used to carry out an upper stroke movement of the upper part.

Consequently, a lifting mechanism with a centrally mounted shaft and without an upper stroke function can easily be converted into a lifting mechanism with an upper stroke function by changing the central bearing of the shaft to an eccentric bearing. In addition, by changing the eccentricity of the eccentric bearing of the shaft, the relationship between the angle of rotation of the shaft and the resulting stroke of the upper stroke movement can be changed.

According to the invention, the upper part is supported on a base of the lifting mechanism, preferably comprising a frame, the shaft being rotatably mounted in the base.

If the shaft is stored and rotated eccentrically with respect to its axis of rotation, the resulting vertical movement of the shaft is transferred to the base and thus to the upper part.

To support the shaft on the frame, at least two support members spaced apart along the shaft can be provided, on which the shaft is each mounted eccentrically with respect to its longitudinal axis. When the shaft rotates, the shaft consequently moves in a vertical direction relative to the support members in order to thereby carry out the upper stroke function.

So that the shaft can be fixed relative to the frame during its rotation in the longitudinal direction, it can be provided according to a further preferred embodiment that the support members are capable of an evasive movement in the longitudinal direction. In this way, the horizontal component resulting from rotation of the eccentrically mounted shaft can be recorded.

Preferably, the support members each comprise a roller or a roller.

While in this way a rotation of the shaft not only causes the lower part to be raised and lowered, but at the same time results in a vertical movement of the shaft, which can be converted into an upward or downward movement of the upper part, this means that the lower stroke of the lower part and the upper stroke of the upper part is positively coupled to one another via a rotation of the shaft.

It is preferably provided that the lower stroke and the upper stroke run in opposite directions to one another. The two lifting movements can therefore support each other, whereby the maximum power to be applied by the drive motor can be significantly reduced.

In a possible practical embodiment, the effective working stroke of the working unit given by the difference between the lower stroke and upper stroke is approximately 75 to 85mm, preferably approximately 80mm.

Preferably, the maximum amount of the upper stroke is approximately 0.2 times to 0.3 times the maximum amount of the lower stroke.

The maximum amount of the upper stroke is preferably around 20 to 30mm, preferably around 25mm.

In particular, it can be provided that the maximum amount of the understroke is approximately 95 to 115mm, preferably approximately 105mm.

These configurations can each be used in combination with the above-mentioned practical configurations regarding the possible angles of rotation of the shaft (in particular approximately 100°) and the motor crank (in particular approximately 150°). the maximum stroke of the lower part, ie for the maximum lower stroke, must be provided.

The invention also relates to a packaging machine with at least one work station according to the invention.

Fig. 1

eine perspektivische Ansicht einer Arbeitsstation mit einem Hubmechanismus gemäß einer ersten Ausführungsform der Erfindung,

Fig. 2 und 3

unterschiedliche Seitenansichten des erfindungsgemäßen Hubmechanismus von Fig. 1, und

Fig. 4 bis 6

verschiedene Ansichten eines Hubmechanismus gemäß einer zweiten Ausführungsform der Erfindung.

The invention is described below by way of example with reference to the drawing. Show it:

Fig. 1

a perspective view of a work station with a lifting mechanism according to a first embodiment of the invention,

Figs. 2 and 3

different side views of the lifting mechanism according to the invention from Fig. 1 , and

Fig. 4 to 6

different views of a lifting mechanism according to a second embodiment of the invention.

At the in Fig. 1 The work station shown is a deep-drawing station of a packaging machine, which comprises a frame 11 standing on the floor with two upper support profiles 51 and two lower support profiles 37, which extend in a conveying direction, also referred to below as the longitudinal direction, in which a film web, not shown in a fundamentally known manner through the packaging machine and thus through the in Fig. 1 shown deep-drawing station is conveyed through. Chain guides (not shown) are attached to the inside of the support profiles 51 for guiding conveyor chains, also not shown, which hold the continuous film web laterally in a generally known manner.

In the Fig. 1 Film plane 55, indicated by dashed lines, in which the film conveyor device (not shown) and the film web lie during operation, represents the reference plane for the tool of the deep-drawing station shown. In practice, this reference plane is usually slightly below the upper edge of the support profiles 51. In this case The tool is a working chamber, also known as a deep-drawing chamber, which includes a lower part 15 and an upper part 13. The height of this reference plane above the floor on which the frame 11 of the deep-drawing station and the packaging machine stand is predetermined by the packaging machine, so that the movements of the lower part 15 and the upper part 13 of the working chamber of the deep-drawing station must be coordinated with the position of the film plane 55 .

The lower part 15 and the upper part 13 are supported by a lifting mechanism explained in more detail below, which is inserted as an independent functional unit into the work station between the two lower support profiles 37 and the two upper support profiles 51. The lifting mechanism is carried as a whole by the frame 11 and is supported exclusively on the support profiles 37 by means of support elements in the form of rollers 35.

The two upper support profiles 51 and the two lower support profiles 37, on which the lifting mechanism is supported via the rollers 35, are attached to the outer sides of two plate-like transverse elements 53 spaced apart in the longitudinal direction, which are supported on the floor with feet 57. The lifting mechanism is therefore located within a frame formed by the frame 11 as a supporting structure, which includes the two transverse elements 53, the two upper support profiles 51 and the two lower support profiles 37.

The following based on Fig. 1 The lifting mechanism explained in terms of its basic structure will then be discussed in conjunction with the Fig. 2 to 6 described in more detail.

The basic structure of the lifting mechanism comprises a box-shaped frame at the bottom made of two lateral, longitudinally extending longitudinal beams 20, which are connected to one another by two cross beams 22. This frame forms a stable base for the lifting mechanism.

Several - in the exemplary embodiment Fig. 1 three shafts 17 are rotatably mounted in the area of their ends in the longitudinal beams 20 of the frame. The already mentioned support rollers 35 are connected to the end faces of the shafts 17, so they are not directly connected to the longitudinal beams 20 of the frame.

The support of the lifting mechanism on the frame 11 is therefore characterized by the fact that the shafts 17 are supported on the one hand via the rollers 35 on the support profiles 37 of the frame 11, and on the other hand the shafts 17 support the longitudinal beams 20 and thus the frame and consequently the entire lifting mechanism carry.

The frame comprising the longitudinal beams 20 and the cross beams 22 forms a base of the lifting mechanism, on which the upper part 13 of the working chamber is directly supported. For this purpose, columns 27 are provided, which are each supported vertically above one of the shafts 17 on the longitudinal beams 20 and carry a respective longitudinal element 59 of the upper part 13.

Between the lower end of each column 27 and the respective longitudinal beam 20 of the frame, a manually operable height adjustment is provided, which enables the distance between the upper part 13 and the frame to be adjusted, so that the position of the upper part 13 in relation to the position of the lower part 15 when closed Condition can be set exactly and the film thickness in particular is taken into account.

Due to the support of the lifting mechanism on the frame 11 via the rollers 35, the lifting mechanism is a carriage that can be moved in the longitudinal direction relative to the frame 11 when setting up the packaging machine. The lifting mechanism is not completely freely movable, but is coupled to the frame 11 via a fixing device in the form of a spindle drive comprising a spindle 39 and a spindle nut 41. The spindle 39 extends in the longitudinal direction and is attached to the frame 11 in such a way that it can be rotated about its longitudinal axis by manual operation. By rotating the spindle 39, the spindle nut 41 connected to the column 27 is acted upon in the longitudinal direction and the lifting mechanism is thereby moved in the longitudinal direction. The longitudinal position of the lifting mechanism in the frame 11 can therefore be changed and adapted to a respective application, but during the deep-drawing operation the longitudinal position of the lifting mechanism is fixed by the fixing device formed by the spindle drive 39, 41.

To carry out an upper lift, which is explained in more detail below, the lifting mechanism as a whole can be raised and lowered. This means that the frame 20, 22 can be raised and lowered relative to the frame 11 together with the upper part 13 supported by the columns 27 and with the lower part 17 carried by the shafts 17. In order to make this upper stroke possible, the spindle nut 41 is mounted on the relevant column 27 so that it can be moved longitudinally.

The lower part 15 is supported on the shafts 17 via a gearbox described in more detail below, of which in Fig. 1 a pair of congruent and spaced-apart push rods 23 are shown, between which a carrier 16 of the lower part 15 is articulated.

The waves 17 are through an in Fig. 1 Common synchronization coupling 43, not shown, is connected to one another and thereby mechanically synchronized. The actuation of the synchronization coupling 43 for synchronous rotation of the shafts 17 is carried out by a drive motor 19 arranged outside the frame 20, 22 at the height of the shafts 17. The motor 19 is on the in Fig. 1 rear cross member 22 of the frame is supported and installed transversely to the extent that the in Fig. 1 Drive shaft, not shown, of the motor 19 extends parallel to the shafts 17.

On the outer sides of the two supports 16 of the lower part 15, an outwardly projecting tab 61 is attached, which is guided along one of the columns 27 supporting the upper part 13 on the longitudinal beam 20 of the frame. As a result, the lower part 15 is guided on the upper part 13 when a lower stroke is carried out. The lower part 15 and the upper part 13 are precisely aligned relative to one another in this way.

The Fig. 2 to 6 show a first exemplary embodiment ( Fig. 2 and 3 ) and a second exemplary embodiment ( Fig. 4 , 5 and 6 ) of a lifting mechanism according to the invention. The lifting mechanism according to Fig. 2 and 3 corresponds to the lifting mechanism of the in Fig. 1 workstation shown. The lifting mechanism according to the Fig. 4 , 5 and 6 is basically like the lifting mechanism Fig. 2 and 3 constructed, but has a smaller working length intended for smaller tools and is provided with only two shafts 17, whereas the lifting mechanism according to Fig. 2 and 3 has three shafts 17 arranged one behind the other in the longitudinal direction.

In some illustrations, some components are not shown in order to clarify special features of the structure. For example, in Fig. 2a In the left gearbox, the roller 35 and the front push rod 23 in this side view are not shown. In Fig. 2b for example, the rollers 35 and the front push rods 23 are not shown in any of the three transmissions. On the other hand, in Fig. 2b the motor shaft 29 can be seen. This applies accordingly to the 3a and 3b . In addition, they show Fig. 2a and 3a each has a front support profile 37, whereas in the Fig. 2b and 3b in each case a rear support profile 37 of the frame is shown. In the Fig. 4 , 5 and 6 the lifting mechanism is shown without components belonging to the frame.

Due to the basically the same structure, the following statements apply to the exemplary embodiment Fig. 2 and 3 also for the exemplary embodiment Fig. 4 , 5 and 6 .

In the Figs. 2a and 2b the lower part 15, of which a longitudinal beam 16 is shown, is in the maximum lowered position, ie the working chamber comprising the lower part 15 and the upper part 13 is open. On the other hand, they show 3a and 3b the state of the work station with the working chamber closed, in which the lower part 15 is in the maximum raised position.

The lifting mechanism here is also provided with an upper lift function for the upper part 13: With the chamber open according to Figs. 2a and 2b the upper part 13 is in the maximum raised position, whereas the maximum lowered position of the upper part 13 with the working chamber closed is in the 3a and 3b is shown.

The lower stroke movement of the lower part 15 and the upper stroke movement of the upper part 13 are positively coupled to one another via the shafts 17 and run in opposite directions to one another, that is, a raising of the lower part 15 is connected to a lowering of the upper part 13, and vice versa. The shafts 17 are synchronized with one another via a synchronization coupling 43, which acts on the shafts 17 via a shaft crank 25 which is connected in a rotationally fixed manner to the respective shaft 17. The synchronization coupling 43 is pivotally connected to the shaft cranks 25 about a joint axis 81.

The rotation of the shafts 17, which are synchronized with one another, takes place by means of a single electric motor 19, which acts on the shaft 17 on the left in the figures, namely via a motor crank 31 connected to a drive shaft 29 of the motor 19, which is articulated to the shaft crank 25 via a drive coupling 33 this shaft 17 is connected.

Starting from the open position according to the Figs. 2a and 2b the motor 19 rotates the motor crank 31 by approximately 150° counterclockwise, whereby all shaft cranks 25 together with the shafts 17 also rotate synchronously counterclockwise, namely by a rotation angle of approximately 100°. There is therefore a reduction between the motor crank 31 and the shafts 17.

The rotation of the motor cranks 25 is converted into a movement of the two push rods 23, whereby the relevant longitudinal beam 16 of the lower part 15 is moved upwards.

As already mentioned elsewhere, the structure of the two individual gears at the left end and at the right end of each shaft 17 is identical, i.e. each shaft 17 engages at two points spaced apart in the transverse direction with an arrangement of motor crank 25 and push rods 23 on the relevant longitudinal beam 16 of the lower part 15. The motor 19, on the other hand, is only connected to the rear shaft crank 25 in the side view selected here via the motor crank 31 and the drive coupling 33.

The design of the lifting mechanism chosen in the two exemplary embodiments described here is advantageous in several respects:
With the working chamber closed in accordance with 3a and 3b the toggle lever arrangements formed by a shaft crank 25 and the associated push rods 23 are each in a vertically extended position. The bottom part 15 therefore exerts no torque on the shafts 17 in this neutral position of the transmission. The entire effective weight is diverted directly via the shafts 17 and the support rollers 35 connected to the shafts 17 into the longitudinal beams 37 and thus into the frame of the work station.

In the open position of the working chamber according to Figs. 2a and 2b the four-bar mechanism formed by the drive shaft 29 of the motor 19, the motor crank 31, the drive coupling 33 and the shaft crank 25 is also in a neutral position in the sense of an extended state in which the relevant axes lie in a common plane. The relevant axes are the axis of rotation 65 of the drive shaft 29 of the motor 19, the joint axis 63 between the motor crank 31 and the drive coupling 33, and the joint axis 67 between the drive coupling 33 and the shaft crank 25. This stretched state results in that the shaft crank 25 can no longer rotate clockwise, and the overall effective weight of the lower part 15 and the gearbox cannot therefore exert any torque on the drive shaft 29 of the motor 19. When the working chamber is open, ie when the lower part 15 is lowered to the maximum, the motor 19 is therefore free from external forces. The motor 19 therefore does not need to be subjected to a holding current to generate a torque that counteracts a weight force. In particular, when the working chamber is open, it is possible to easily replace the force-free motor 19 if necessary or to separate it from the motor crank 31 for other reasons.

In addition, the movable parts and their connections are optimized and arranged relative to one another in such a way that, taking into account an upper stroke movement of the upper part 13, which is explained in more detail below, an optimal force or torque curve is achieved without disadvantageous force or torque peaks over the entire opening or .Closing movement of the working chamber, i.e. over the entire angle of rotation of the motor crank 31 or the shafts 17.

Relative to the shafts 17 and thus to a reference system of only the lifting mechanism, the movement sequence of the lower stroke of the lower part 15 described above is independent of the way in which the lifting mechanism is supported on the frame 11 (cf. Fig. 1 ) or on the support profiles 37 of the frame. In relation to the frame 11 supported on the floor and thus to the film level 55, which assumes a fixed height relative to the frame 11, on the other hand, the maximum stroke of the lower part 15 relative to the shafts 17 (as mentioned in the introductory part, for example 105mm) does not correspond to the effective working stroke of the working chamber ( e.g. 80mm). The reason for this is that the rotation of the shafts 17 caused to carry out the lower stroke of the lower part 15 simultaneously results in the shafts 17 lowering. The lowering of the shafts 17 results in a downward movement of the entire lifting mechanism, including the upper part 13, which is supported on the shafts 17 via the columns 27, relative to the frame and thus relative to the film plane 55. The upper stroke is, for example, 25mm, so that the mentioned maximum effective working stroke from 105mm - 25mm = 80mm, which is designed to be sufficiently large for applications with a required effective working stroke of the working chamber of around 75mm.

The lowering of the shafts 17 is achieved by eccentrically mounting the shafts 17 on the support rollers 35. This concept can be illustrated particularly well using the Fig. 2a and 3a can be understood, in which the support roller 35 is not shown on the left gearbox. Instead, it can be seen there that the axes of rotation 18 of the shafts 17 do not coincide with the axes of rotation of the support rollers 35, which are also referred to below as eccentric axes 36. The eccentricity, ie the radial distance between the axis of rotation 18 of the shaft 17 and the eccentric axis 36 determines - for a given maximum angle of rotation of the shaft 17 - the maximum stroke path of the upper stroke.

With the working chamber closed according to Fig. 3a , i.e. in the extended state of the toggle lever arrangement consisting of shaft crank 25 and push rods 23, the eccentric axes 36 also lie in the common vertical plane of the joint axis 71, joint axis 73 and shaft rotation axis 18. The eccentric axes 36 each lie vertically above the rotation axis 18 of the shaft in question 17, ie the shafts 17 and thus the entire lifting mechanism, in particular including the upper part 13, are lowered to the maximum with respect to the frame.

With the chamber open according to Fig. 2a On the other hand, the shafts 17 and thus the upper part 13 are raised to the maximum with respect to the frame, starting from an angle of 0 ° with the chamber closed Fig. 3a a common plane of shaft rotation axis 18 and eccentric axis 36 includes the above-mentioned angle of approximately 100 ° to the vertical. This angle is the maximum angle of rotation of the shafts 17.

Since the entire lifting mechanism is firmly connected in the longitudinal direction to the spindle 39 and thus to the frame via the spindle nut 41 which interacts with the right column 27, the evasive movement in the longitudinal direction required due to the eccentric movements of the shafts 17 around the support rollers 35 is not caused by the lifting mechanism, but rather carried out by the support rollers 35, which roll on the support profiles 37 of the frame. This can be done, for example, in the Fig. 2a and 3a can be particularly well understood based on the positions of the rollers 35 in the longitudinal direction relative to the columns 27 which are fixed in the longitudinal direction.

At the same time, the support rollers 35 enable the lifting mechanism to be positioned in the longitudinal direction by manually rotating the spindle 39, as already described above.

In this respect, the lifting mechanism is a carriage which can be moved in the longitudinal direction on the support profiles 37 of the frame, with wheels formed by the support rollers 35 arranged eccentrically with respect to the axes of rotation 18 of the shafts 17 and with a stable base formed by the frame comprising the longitudinal beams 20 and the cross beams 22. The shafts 17 are rotatably mounted in this base, which thus carry the upper part 13 via the columns 27 and the longitudinal beams 20 and the lower part 15 via the gears formed by the shaft crank 25 and the push rods 23.

The above statements also apply in principle to the exemplary embodiment Fig. 4 , 5 and 6 , which show a lifting mechanism according to the invention with only two shafts 17. In principle, the inventive concept of the lifting mechanism and its arrangement and support in a frame of a respective work station, as described here, can be applied to any number of shafts 17 arranged one behind the other in the longitudinal direction.

While in the Fig. 4a , 5a and 6a In each case the open state is shown with the lower part 15 lowered to the maximum and the upper part 13 raised to the maximum Fig. 4b , 5b and 6b the status of the lifting mechanism when the chamber is closed.

Furthermore, in Fig. 4 and 6 in each case a plate-shaped cross strut 45 for the lower part 15 connecting the two supports 16 of the lower part 15 is shown.

The supports 16 and the cross strut 45 of the lower part 15 as well as the longitudinal elements 59 of the upper part 13 represent functional blocks for the lower chamber and the upper chamber (not shown) and are provided with the electrical and pneumatic connections and connections required for the operation of the working chamber.

Furthermore, the illustrations in Fig. 6a and Fig. 6b in particular the symmetrical structure of the individual gears, in which the carrier 16 of the lower part 15 and the shaft crank 25 are arranged between the pair of push rods 23. This simplifies the design of the rotary bearings between the push rods 23 and the carrier 16 on the one hand and the push rods 23 and the shaft crank 25 on the other hand, since tilting moments and the resulting transverse forces are avoided or at least minimized. The guide tabs 61 for vertically guiding the lower part 15 on the columns 27 can therefore be made comparatively simple. This also underlines the extremely robust and low-maintenance overall structure of the lifting mechanism.

Furthermore, the representations in the Fig. 4 and 6 It can be seen that the movable parts for raising and lowering the lower part 15 as well as the rollers 35 mounted eccentrically on the shafts 17 for supporting the entire lifting mechanism on the frame and for carrying out the upper stroke are arranged relatively far out laterally and are therefore easily accessible. In addition, this means that the interior of the lifting mechanism is available for other purposes, in particular for tool-specific components and connecting cables.

A further advantage of the lifting mechanism according to the invention is that the integration of the upper stroke movement does not involve any significant additional effort, but only requires the explained eccentric connection between the shafts 17 and the support rollers 35 instead of a centric connection that is also possible in principle.

Reference symbol list

11

frame

13

Top

15

Bottom part

16

Carrier of the bottom part

17

Wave

18

Axis of rotation of the shaft

19

drive motor

20

Longitudinal beam

21

Base, frame

22

Cross beam

23

push rod

25

Shaft crank

27

pillar

29

drive shaft

31

Engine crank

33

drive coupling

35

supporting organ, role

36

Eccentric axis

37

Support profile

39

spindle

41

spindle nut

43

Synchronization coupling

45

Cross brace

51

Support profile

53

Cross element

55

Foil layer

57

Stand

59

Longitudinal element

61

tab

63

Joint axis

65

Axis of rotation

67

Joint axis

71

Joint axis

73

Joint axis

81

Joint axis

Claims (14)

1. A working station, in particular a deep-drawing station, a molding station, a sealing station, a cutting station or a punching station, for a packaging machine, comprising

   - a rack (11) supported on the ground;

   - a work unit comprising an upper part (13) and a lower part (15); and

   - a lifting mechanism which is carried by the rack (11) and by which the lower part (15) of the work unit can be raised and lowered relative to the rack (11) to perform a lower stroke,

   wherein the lifting mechanism has a drive which comprises at least one shaft (17) extending in a transverse direction; a drive motor (19) engaging at the shaft (17) for rotating the shaft (17); and at least one gear (23, 25, 61, 71) which is coupled at an input side to the shaft (17), at which the lower part (15) is supported at an output side and which converts a rotation of the shaft (17) into the lower stroke of the lower part (15),

   wherein the shaft (17) is supported at the rack (11) and carries a base (21) of the lifting mechanism in which the shaft (17) is rotatably supported and at which the upper part (13) is supported,

   wherein the shaft (17) of the lifting mechanism is supported via a plurality of support members (35), in particular rollers or shafts, at the rack (11),

   characterized in that

   the lifting mechanism is adjustable, in particular movable, relative to the rack (11) in the longitudinal direction by means of the support members (35).
2. A working station according to claim 1,
   wherein the base (21) comprises a frame.
3. A working station according to claim 1 or 2,
   wherein the gear (23, 25, 61, 71) is configured as a coupling gear, preferably as a slider crank gear which is in particular central.
4. A working station according to any one of the preceding claims,
   wherein the gear (23, 25, 61, 71) comprises a toggle lever arrangement, in particular wherein the toggle lever arrangement is stretched in a position with the lower part (15) raised to the maximum, said position in particular corresponding to a closed work unit.
5. A working station according to any one of the preceding claims,
   wherein the gear (23, 25, 61, 71) comprises at least one pair of congruent and mutually spaced apart connecting rods (23) between which a shaft crank (25) rotationally fixedly connected to the shaft (17) is connected in an articulated manner at the input side and the lower part (15) or a support for the lower part (15) is connected in an articulated manner at the output side, and/or wherein the shaft (17) is rotatably supported in longitudinal supports (20) of the base (21) which are spaced apart from one another in the transverse direction.
6. A working station according to any one of the preceding claims,
   wherein the gear (23, 25, 61, 71) comprises at least two individual gears which are spaced apart along the shaft (17) and which are synchronized by means of the shaft (17) for a joint performance of the lower stroke, and/or wherein the lifting mechanism comprises a plurality of synchronized shafts (17) which are spaced apart along the rack (11) and which each have a gear (23, 25, 61, 71) for the joint performance of the lower stroke.
7. A working station according to any one of the preceding claims,
   wherein, during the lower stroke, the lower part (15) is guided at the base (21), at the upper part (13) or at a column (27) supporting the upper part (13) at the base (21).
8. A working station according to any one of the preceding claims,
   wherein the upper part (13) is vertically adjustably supported at the base (21), and/or wherein the upper part (13) is supported at the base (21) via a plurality of columns (27), in particular vertically adjustable columns (27).
9. A working station according to any one of the preceding claims,
   wherein the drive motor (19) engages at the shaft (17) via a coupling gear (29, 31, 33, 25), in particular wherein, in a position with the lower part (15) lowered to the maximum, the torque applied to a drive shaft (29) of the drive motor (19) via the coupling gear is zero or approximately zero.
10. A working station according to claim 9,
    wherein the coupling gear is configured as a four-bar linkage which comprises a drive shaft (29) of the drive motor (19); a motor crank (31) connected to the drive shaft (29); a drive coupling (33) connected in an articulated manner to the motor crank (31); and a shaft crank (25) rotationally fixedly connected to the shaft (17) and connected in an articulated manner to the drive coupling (33), in particular wherein, in a position with the lower part (15) lowered to the maximum, the axis of rotation (65) of the drive shaft (29) of the drive motor (19), the articulated axis (63) between the motor crank (31) and the drive coupling (33), and the articulated axis (67) between the drive coupling (33) and the shaft crank (25) lie at least approximately in one plane.
11. A working station according to any one of the preceding claims,
    wherein the base (21) can be lowered and raised relative to the rack (11) to perform an upper stroke of the upper part (13), and/or wherein the lower stroke and the upper stroke are positively coupled to one another, in particular via a rotation of the shaft (17), and/or wherein the upper stroke and the lower stroke extend in opposite senses to one another.
12. A working station according to any one of the preceding claims,
    wherein the rack (11) has at least two support sections (37) which extend spaced apart in parallel in the longitudinal direction, at which the lifting mechanism is supported and along which the lifting mechanism is adjustable relative to the rack (11).
13. A working station according to any one of the preceding claims,
    wherein a fixing device (39, 41) is provided by means of which the position of the lifting mechanism in the longitudinal direction can be fixed at the rack (11), in particular wherein the fixing device comprises a spindle drive (39, 41) for setting the longitudinal position of the lifting mechanism.
14. A packaging machine comprising at least one working station according to any one of the preceding claims.

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