NO144131B - DRIVE DEVICE FOR THERMOFORM MACHINES. - Google Patents

Description

The invention relates to a drive device for thermoforming machines with at least one lifting and lowering support beam for the molding tools and their auxiliary devices, such as tension aids, ejectors and the like, where the drive device by means of a cam drive with a cam follower designed as a swing arm converts the turning movement of one or more motors into another the support beam's lifting and lowering device by means of a link rod articulated to the swing arm transferable back and forth movement and to a forward movement for the strip or sheet material to be shaped and possibly has been shaped.

Drive devices for thermoforming machines are known, in which a central shaft carrying a chamber is arranged under the support beam for the forming tools and their auxiliary devices (US-PS 3172159, CH-PS 369893). Directly connected to the support beam or support beams, vertical cam grippers run on the cams and carry out movements back and forth, whereby the cams and cam grippers must be designed to be particularly stable due to the direct load absorption and are nevertheless subject to high wear and tear. Furthermore, these known drive devices also include transmissions

and devices to be able to provide forward movement for the band-shaped plastic material to be shaped, respectively is shaped.

A drive device for thermoforming machines is also known, in which a cam pair is placed on the side of the thermoforming device on the machine frame, which is sensed by means of cam grippers or cam sensors which are designed as swing arms. The movement thus provided by these swing arms is transferred by means of joint rods as forward and backward movement for operating the knee joint devices, which are arranged above and below the support beams for the parts of the thermoforming tool. The knee joint devices are thereby used to provide the necessary closing pressure for the parts of the molding tool.

Both with the first and also with the last drive device, however, it is a disadvantage that the stroke length for the raising and lowering movements provided either directly or via the knee joint devices on the support beam must be determined once and for all and can no longer be adapted to variable requirements. The stroke length must therefore be dimensioned so that it is sufficient for the production of workpieces with maximum depth. The support beams must therefore carry out raising and lowering movements with such a stroke length, even if this is not necessary in the production of shaped pieces or blanks with a smaller depth. The thermoforming machines equipped with the known drive devices therefore have an unnecessarily high power requirement. The drive cycle number cannot be increased when producing workpieces with a smaller depth. The lifting and lowering movements which in any case must be carried out by the support beams and which have a large stroke length also cause unnecessary shocks during operation of the thermoforming machine, especially its transport devices, for the material to be shaped, respectively is shaped. Such shocks are disadvantageous, especially when the thermoplastic material to be supplied to the device has been softened to a large extent.

The task that is therefore the basis of the present invention is to provide a drive device for thermoforming machines, which can be adapted to the necessary requirements for the forming process at all times, in particular the necessary stroke length for the forming tools at all times, thereby also the work rate and a most possible quiet working process for the thermoforming machine must be able to be set optimally.

This is achieved according to the invention by a drive device of the type mentioned at the outset, which is characterized by what appears in the claims.

With the device according to the invention, the size of the stroke length for the lifting and lowering movement provided by the support beam can be adapted to the optimum dimensions for the production of the desired shaped pieces, respectively their depth, by mutual adjustment of the gripper or follower, the joint rod's lifters and the lifting piston, respectively the lifting rod. The device according to the invention thereby provides the advantage that a setting of the stroke number in the working stroke of the thermoforming machine is also possible, e.g. when changing the speed of the drive motor or when changing a transmission. In particular, the working cycle rate for the thermoforming machine can be increased significantly if the lifting and lowering movements of the support beam only have to perform small stroke lengths. By changing the number of working strokes and the stroke length, the device according to the invention can also be set to optimally quiet walking. Setting the stroke length to the prevailing conditions at any given time also means significant savings in the required drive power.

Within the framework of the invention, the connecting rod can be articulated with the follower and/or the lifter by means of eccentric pins. Another favorable setting option appears if the connecting rod is articulated with the follower and/or the lifter by means of a sliding block. In this latter case, the slide block can be set in a circular arc-shaped slide path, the center of curvature of which in rest position is at the joint point at the other end of the joint rod.

A setting of the guide stone thereby only affects the stroke length, but not the once set closing position for the thermoforming tool. Thereby, the alignment of the thermoforming tool is made significantly easier.

According to a further advantageous feature of the invention

in the case of a design that uses a lower and an upper support beam, it is proposed that both support beams are force-lockingly connected to the lifter, whereby the force-locking connection between the upper support beam and the lifter can optionally be set to counterclockwise operation with the lower support beam or to a stationary upper support beam.

For this purpose, the shaft that carries the lifter can include at least one crank pin which is assigned to a pin that is equal to the shaft, whereby at least one, preferably two lifting rods that carry the upper support beam with an eye arranged on each at its lower end can optionally be attached on the crank pin or on the axle pin.

Within the scope of the invention, the lifter can be formed by a first lifting arm attached to the lifting shaft above the connecting rod force-lockingly connected to the follower and two or more second lifting arms attached to the lifting shaft, above each lifting piston with the support beam force-lockingly connected.

With the aid of the invention, as mentioned, a particularly favorable and quiet operation is achieved for the drive device, which makes it possible to supply even relatively delicate material webs coming directly from an extrusion device in a continuous or stepwise manner.

An embodiment of the invention will be described in more detail below with reference to the drawing. Figure 1 shows a drive device according to the invention in a schematic side view and partly in section. Figure 2 shows a somewhat modified part of the device according to Figure 1, shown schematically in section. Figure 3 shows a part of the device according to Figure 1 with the devices that carry and move the upper tool carrier beams.

Figure 4 is an elevation following the line IV-IV in Figure 3.

Figure 5 is a partial section of the area V-V in Figure 4.

Figure 6 is a partial section along the line VI-VI in Figure 4.

Figure 7 is a section along the line VII-VII in Figure 6.

Figure 8 schematically reproduces a detail of the cam and transmission unit according to Figure 1, partially in section. Figure 9 shows a schematic drive device according to the invention for a thermoforming machine with a directly connected injection molding machine for producing the thermoplastic material strip to be shaped. Figure 10 shows another embodiment of the invention in a rendering like Figure 2.

As shown in Figure 1, the drive device according to the invention comprises a cam and transmission unit 1, which is driven by an electric motor not shown. The cam and transmission unit comprises a scanner 2 which is designed as a swing arm and is in contact with the cam which is arranged inside the unit, a sprocket 3 which establishes a connection with internal transmission devices for taking over an intermittent driving or forward movement and a sprocket 4 for taking over of a continuous feed or drive movement.

The actual thermoforming machine contains, according to the simplified rendering in the drawing, a lower, vertically up-and-down movable support beam 5 for molding tools and auxiliary devices and an upper, optionally also vertically up-and-down movable support beam 6 for molding tools and auxiliary devices. Both support beams 5 and 6 are vertically slidingly guided on columns 7 which are arranged on the machine stand 8. Between the cams for the cam and transmission unit 1 and the lower support beam 5 and possibly also the upper support beam 6, an adjustment device is connected which is designed for time setting and which in addition to the above-mentioned scanner 2, a lifter 9 which is arranged under the support beam 5 and designed as a two-arm swing arm, comprises a connecting rod 10 which establishes the connection between the scanner^2 and the lifter 9, and a lifting piston 11 which establishes the connection between the lifter 9 and the support beam 5 and possibly a lifting rod 12 (cf. Figure 3) arranged between the lifter 9 and upper support beam 6.

The link rod 10 is articulated with the scanner 2 and the lifter 9 via eccentric pins 13 and 14. As will be particularly clear from figure 2, the scanner 2's weight arm a, which is effective for the joint rod 10, can be varied by adjusting the eccentric pin 13 and the weight arm b which is effective for the lifter 9 can be varied by adjusting the eccentric pin 14. If the weight arm a on the scanner 2 is set to a maximum value and the weight arm b is set to a minimum value, a maximum stroke length is achieved on the support beam 5 or 6. In contrast, a minimum stroke length is obtained on the support beam 5 or 6, if The external pin 13 on the detector is set for minimum stroke arm a and the eccentric pin 14 on the lifter 9 is set to maximum stroke length b. Between the maximum and minimum stroke length, the stroke length can be set continuously. By choosing the eccentric size in relation to the minimum size of the weight arms a and b, the size of the impact possibilities can be selected. In the present case, a stroke change must be made possible in a ratio of 1:1.5 between minimum and maximum stroke length.

As shown in Figure 2, the cam 15 is formed which induces the impact movement of two cam discs 16 and 17. On each of these cam discs a scanner roller 18 and 19 for the scanner 2 respectively roll, while the scanner is pivotally stored by means of two pins 20 on its sides in the frame for the cam and transmission unit 1. The arrangement of the scanner rollers 18 and 19 on the scanner 2 and the shape of the cam discs 16 and 17 are adapted so that both scanner rollers are in constant contact with the circumferential surface of each cam disc 16 and 17. As soon as one scanner roller 18 runs into a radially narrowed part 16a on its cam disk 16, the other scanner roller 19 goes over a radially protruding part 17a on its cam disk 17. Conversely, the scanner roller 19 goes over a radially narrowed part on its cam disk, when the scanner roller 18 goes onto a radially projecting part 17b on its cam disc 17. With this device, the scanner 2 performs a forced swing movement about its pins 20, in any phase controlled by both cam discs

16 and 17. The movement of the scanner 2 is transmitted by eccentric pins 13

to the connecting rod 10, which in turn converts its movement via eccentric pins 14 into a swinging movement of the lifter 9. The swinging movement of the lifter 9 is in turn transmitted via the lifter piston 11 to the lower support beam 5 and possibly to the upper support beam 6 via a pair of lift rods 12. The cam 15 performs a continuous turning movement caused by the electric motor, while the lifting and lowering movement of the support beams 5 and 6 is exclusively determined by the circumferential shape of the cam discs 16 and 17. The working rate of the support beams 5 and 6 can be varied by means of a continuously adjustable reduction gear arranged between the drive motor and the cam 15 or by changing the speed of the drive motor. In order to achieve a self-locking effect of the closed form tools, it is appropriate to arrange the lifting shaft 21 and the lifting piston 11 joint connection points 22 and 23, as well as the lifting shaft 21 and the lifting rods 12 joint connection points 24 and 25 in one plane at the closed position of the forming tools. To achieve this, the length of the connecting rod 10 is adjustable, so that the desired self-locking position of the parts in closed form can be set at any position of the eccentric pins 13 and 14. In order for the position of the support beam 5 to be adjustable in closed form, the lifting piston 11 is also length adjustable . If desired, the lifting rods 12 can also be length-adjustable.

In order that the up and down movement of the support beam 5 and the molded parts or auxiliary devices arranged thereon do not cause shocks that are transferred back to the cam and transmission unit and disturb the quiet operation of the entire machine and its drive device, a weight compensation device is provided with at least one force storage device under the lower support beam 5. In the example according to figure 1, this weight equalization device comprises four compressed air cylinders 26 which grip under the four corner parts of the lower support beam 5 and with their connections on the pressure side are mutually connected in parallel to a compressed air container 27, which by means of a device 28 for regulated supply or outlet and measurement of the pressure in the pressure container can be brought to the desired bias. Together with the compressed air cylinder which is held under pretension, the compressed air cylinders 26 form a power bearing which, to a degree determined by the selected pretension in the compressed air container 27, slows the downward movement of the support beam "5" and supports the upward movement of the support beam 5, so that harmful impacts are avoided. As shown in figure 2, the weight equalization device can also be equipped with hydraulic cylinders 29 which are connected to a hydraulic container 30 which works with air cushions. The hydraulic container 30 again includes devices 28 for optional setting of the pretension in the air cushion. In the embodiment shown in figure 4 , there are only two hydraulic cylinders 29 arranged diagonally under the lower support beam 5. Analogous to the example in Figure 1, however, four such hydraulic cylinders 29 can be arranged. However, it is also possible to use only one hydraulic or pneumatic cylinder, which can then optionally be arranged in the middle area under the lower support beam.As will be seen of Figures 1 and 2, the piston rods for the pneumatic or hydraulic cylinders 26 and 29 respectively are only in contact with the underside of the lower support beam

5. It is therefore immediately possible to let the forming machine work

without the weight equalization device by removing the bias in the compressed air container 27 and the hydraulic container 30. The bias in the compressed air container 27 or the hydraulic container 30 can also be chosen as low as it is admittedly in the downward

movement of the support beam 5 occurs a certain braking and damping effect, but that the upward movement of the support beam 5 caused by the cam 15 occurs faster than the upward movement of the piston rods of the cylinders 26 and 29 respectively, i.e. that the upward movement of the support beam 5 for closing of the shape is not affected by the compressed air cylinder 26 or the hydraulic cylinder 29. With the help of a pressure medium valve, it is achieved that the transmission works practically weightless, i.e. with constant pressure on the pistons of the compensating cylinder 26, the same force is produced at all times with the same weight.

In the example shown in the drawing, the thermoforming machine is equipped with a lower up-and-down movable support beam 5 bg an upper up-and-down movable support beam 6. In principle, the invention "also has significance for machines which only comprise a up-and-down moving support beam, possibly with a stationary opposite support yoke.

In the example shown, however, a universally applicable thermoforming machine is arranged which comprises a lower up-and-down movable support beam 5 and an upper support beam 6 which can optionally stand still or be driven up and down in counter-stroke to the lower support beam 5. For this purpose the lifting shaft 21 for the power-transmitting connection between the lifter 9 and upper support beam 6 is provided with a crank pin 31 with an assigned concentric pin 32 that can be lowered axially into the shaft 21. The lifting rod 12 with its lower eye 33 can optionally be placed on the crank pin 31 or the concentric pin 32. When the lifting rod 12 is placed on the crank pin 31, the concentric pin 32 must be recessed on the short side of the shaft 21. As shown in Figure 3, the upper support beam 6 will, as a result of the connection points 22 and 24 on the shaft 21, then perform an up and down movement_in countermeasure to the lower support beam. The stroke length of the upper support beam 6 movement is then determined in comparison with the stroke length of the lower support beam 5 by choosing the distance of the connection points 22 and 24 respectively from the axle 21. The stroke length of the upper support beam 6 is also varied in the manner mentioned above together with the setting of the lower support beam stroke length.

If the lifting rod 12 with its lower eye 33 is placed on the concentric pin 32 which is pulled forward by the shaft 21, only the pin 32 will be turned within the eye 33 when turning the shaft 21, and the upper support beam 6 is stationary.

When the upper support beam 6 is moved in counter-stroke to the lower support beam 5, the weight to be balanced is significantly less, so that a significantly lower preload is set on the hydraulic container 30 (or a compressed air container 27 according to Figure 1) than in a case where the upper support beam is stationary .

Figures 4-7 show details of the lifter 9. This thus comprises a lifter shaft 21, on which the individual lifter parts are attached. The lifting shaft 21 is stored in two bearing parts 34 in the bearings 35, whereby the bearing parts 34 are attached to stable cross members 36

on the machine frame 8. The lifting shaft 21 carries a first lifting arm 37

in the middle area. The lifting arm 37 is in power-transmitting connection with the scanner 2 via the connecting rod 10. In the vicinity of the first lifting arm 37, a pair of other lifting arms 38 are attached to the shaft 21. Between the two lifting arms 38, the lifting piston 11 is stored with a lower eye. If desired, two or more pairs of other lifting arms 38 can be arranged. At each end of the shaft 21, a crank 39 is arranged, each with its own crank pin 31 and a concentric pin 32. In the left part of figure 4, the lifting rod 12 with its lower eye 33 placed on the crank pin 31, while the rod 12 in the right part of Figure 4 with its lower eye 33

is placed on the concentric pin 32 and the crank pin 31 rotates freely.

As shown in figure 5, the crank pin 31 is inserted into the crank 39 which is slotted at the end and pulled to it by contraction of the slotted parts of the crank 39. The crank is crimped onto the end of the lifting shaft 21, optionally wedged as indicated at 40. At each end of the shaft 21 there is a bore 41, where the concentric pin 32 is inserted. The concentric pin 32 is held and locked in the "extracted" and "inserted" positions by turned slots 42a and 42b and the clamping screw 43.

On the other hand, the concentric pin 32 is provided with a concentric threaded bore 44 in the short side, where a tool is screwed in to extract the concentric pin 32 from the bore 41

and possibly for pushing the pin 32 into the bore 41. The threaded bore 44 can also be used to screw a securing washer over the pin 32, when the lower eye 33 of the rod 12 is placed on the pin 32.

Figures 6 and 7 show the design of the first lifting arm 37, which

is crimped onto the shaft 21 and can be wedged as indicated at 43. The first arm 37 is slotted at its free end and receives an eccentric bolt 46 there. An eccentric pin 14 is eccentrically designed on the eccentric bolt 46 which is stored in the first arm 37. The eccentric bolt 46 is at the end facing away from the eccentric pin designed with two or three through bores 47 for cooperation with a tool and has a radially projecting stop pin 48a. On the first lifting arm 37 there are counter-stop pins, a counter-stop pin 48b which cooperates with the stop pin 48a for the maximum position (smallest weight arm) and a counter-stop pin 48c for the minimum position (largest weight arm), or stop pins for setting the maximum respectively minimum position. To set the eccentric pin 14, the clamping connection 49 at the end of the first weight arm 37 must be loosened and the eccentric bolt 46 can then be turned into the desired position with a tool.

As shown in Figure 8, the cam and transmission assembly comprises 1

a feed cam 50 which is driven synchronously with the lifting cam 15 (figure 2) and which in steps drives the sprocket 3 which carries the drive chain 51 for the material path's transport device 52, see figure 9.

the cam 50 is formed by a pair of feed cams 50a and 50b. Each cam disc 50a and 50b has a protrusion, whereby the protrusions 53

are similarly designed, but face each other. On the cam discs 50a and 50b runs a scanner 55, which is provided with two pairs of scanner members, preferably scanner rollers 54, and which sits on the same axle as the sprocket 3. The scanner rollers 54 are arranged so that each scanner roller 54 for each pair always runs on the surface of a of the feed cams. As soon as the feed cam discs move with the projection 53 towards the appropriate assigned scanning roller 54, the feed scanner 55 is turned until the projections 53 of the two cam discs 50a and 50b have passed the scanning roller 54 which until then has run on the feeding cam discs 50a and 50b and has lifted this scanner roller pair and has placed the scanner rollers 54 for the second pair on the peripheral surface of the cam discs 50a and 50b. This induces a rotation of the feed scanner by 180°. The scanner rollers 54 for the second pair then run over the circumferential surface of the feed cams 50a and 50b, until the protrusions again come within their area.

Until then, no further turning movement of the feed scanner 53 takes place. Only when the protrusions 53 pass the scan rollers 54, a rotation of the feed scanner again by 180° takes place. Due to the synchronous operation of the feed cam 50

and the lifting cam 15 in this way induces a feed movement for the material path to be formed, each time the mold is opened,

i.e. the support beams 5 and 6 (see figure 2) are moved apart so that the molding tool is in the opening phase and the molding pieces can pass.

Figure 9 shows the drive device according to the invention in a thermoforming machine 57 with a pre-connected plastic extruder 56 for the material web A to be formed in the thermoforming machine 57. In connection with the plastic extruder 56 follows a cooling and stabilizing device 58, which comprises a first cooling roller 59, a second cooling roller 60

and a counter pressure roller 61 which cooperates with the first cooling roller 59 and is not driven. Second cooling roller 60 is, as indicated by the double arrow 62, adjustable approx. 90° around the first cooling roller 59 so that the wrapping angle of the material web around the two cooling rollers 59 and 60 can be varied. The two cooling rollers 59 and 60 are driven in accordance with the continuous feeding of the material web A by the continuously running sprocket 4 for the cam and transmission unit 1, as ahgyed at the chain connection 63 and 64.

In connection with the cooling and stabilization device 58 follows a device 65 for movement conversion, which in the example shown comprises an upwardly moving tumbling roller. The tumbling roller 66 is held on the side facing the injection molding device 56 in a continuous chain device 65, the operation of which is connected to the continuously running chain connection 63. On the side facing the thermoforming machine, the tumbling roller 66 runs in an intermittent chain device 68, the operation of which 69 is connected to the intermittent chain 51 for the feed device 52. As a result of the continuous operation of the chain device 67, the tumbler is constantly lifted in accordance with the fed amount of manufactured, strip-shaped material A, as long as the intermittent feed device 52 is stationary. As soon as the feed device 52 is driven via the sprocket 3 and the chain 51 in the working stroke of the thermoforming machine 57,

the second chain device 63 of the tumbling roller also starts and causes the tumbling roller to be lowered in accordance with the material path length supplied to the thermoforming machine 57. The total feed amount must be the same for both types of movement. This is ensured by the cam and transmission unit's drive devices which are connected to sprockets 3 and 4.

Figure 9 shows an upwardly arranged tumbling roller 66. The movement conversion device 65 will, with the upward movement of the tumbling roller 66, take up the continuously delivered material path A at a constant, medium speed while overcoming the material path A's own weight. During the intermittent withdrawal, the more or less jerky downward movement takes place, i.e. in the direction of action of the material web A's own weight.

As shown in Figure 9, the intermittently driven transport device 52 for the material path A can extend over such a large length in front of the thermoforming machine 57 that an equalizing resting station 70 is possibly formed between the device 65 for movement conversion and the thermoforming machine 57. This equalizing and resting station 70 can have a length corresponding to an integer value of a feed step or a multiple of the integer value.

Figure 10 shows a somewhat modified embodiment of a thermoforming machine, based on the machine shown in Figure 2.

The parts that have been discussed in connection with Figure 2 and have remained unchanged, are denoted by the same reference number as in Figure

2. Compared to Figure 2, the following changes are proposed:

1. As will be seen from figure 10, the stroke height regulation in this embodiment is not by means of eccentric pins as shown in figure 2, but by means of a slide block 13a which is placed on the scanner 2, while the eccentric pin is replaced by a normal pin bearing 14a. The stroke-height adjustment of the guide stone 13a which is connected to the joint rod 10, takes place with the help of the spindle 13b. The arrangement of the guide stone 13a on the scanner 2 has the advantage that the adjustment range is greater and that the stroke length can be adjusted quickly and steplessly. In the rest position shown in Figure 10, the slide path 13c extends along a circular arc about the axis of the journal bearing 14a, whereby the rest position of the lifter 9 remains unaffected by any adjustment of the slide stone 13a in the slide path 13b. 2. In the example according to Figure 10, the upper tool carrier 6a is provided with several, e.g. three holes 25a arranged one above the other so that the connection point 25 for the lifting rod 12 can be adapted to upper tools 90 of different heights. (I.; Figure 10 is a clamping frame suggested as an example of an upper tool 90). 3. The embodiment of a thermoforming machine which is shown in Figure 10 comprises on the lower tool carrier or support beam 5 two double-acting, preferably pneumatic pressure medium cylinders 80

instead of those or normal ejection springs that are not shown in figure 2. Such ejection springs have disadvantages in that they require a lot of space in the tool, the torque is difficult to determine and they entail a constant, non-adjustable pressure and must also be replaced when the tool type is changed . The pressure medium cylinders 80, on the other hand, when used as an ejector or a wiping cylinder, have the advantage that they require little space, are arranged outside the tool and the moment of force required at all times can be regulated. Moreover, the cylinders only have to be mounted once and for all in the machine, and when double-acting cylinders are used, the piston rod 81 can also be used as a forced ejector. All functional parts that, when using springs, were previously located in the tool, are available on the machine side when mounting pressure medium cylinders, so that a simplification of the tools is achieved.

Moreover, the cylinder or cylinders may be intended for different tasks. It can e.g. two cylinders are used in connection with adjustable stops 84 for operating the scraper plate 82 via operating rods 83 for forced ejection, while a further one or two cylinders are used for shaping hollow bottoms or for a two-stage ejection, as indicated by the operating plate 85 in the lower part of the shape tool 86.

The three modifications shown in Figure 10 are not dependent on each other. They can be arranged individually or in combination in any embodiment of the invention.

All features of the subject matter of the application which are reproduced in the description, the drawing and the claims may be of significant importance for the invention individually or in any conceivable combination.

Claims (8)

1. Drive device for thermoforming machines with at least one lifting and lowering support beam for the mold tools and their auxiliary devices, such as tension aids, ejectors and the like, where the drive output by means of a cam drive with a cam follower designed as a swing arm converts one or more motors' turning movement into one for the support beam's lifting and lowering device by means of a link rod articulated to the swing arm transferable back and forth movement and to a forward movement for the strip or sheet material to be shaped and possibly shaped, characterized in that between the swing arm designed, on the cam (15) acting follower (2), respectively its connecting rod (10), and the support beam (5, respectively 6) are arranged a located below the support beam (5, 6), as a two-arm swing arm designed lifter (9) and a lifting piston (11), respectively a lifting rod (12), which connects the lifter (9) and the support beam (5, 6), the distance between the connecting rod (10) joint point on the follower (2) and the follower's wing axis (20) and/or the distance between the connecting rod (10) joint point on the lifter (9) and the lifter's swing axis (21) is adjustable, whereby the stroke of the support beam(s) (5, 6) can be adjusted. 2. Drive device according to claim 1, characterized in that the connecting rod (10) is articulated with the follower (2) and/or the lifter (9) by means of eccentric pins (13, 14). 3. Drive device according to claim 1, characterized in that the connecting rod (10) is articulated with the follower (2) and/or the lifter (9) by means of a slide block (13a). 4. Drive device according to claim 3, characterized in that the slide block (13a) is adjustable in a circular arc-shaped slide track (13c), whose center of curvature at the device's rest position is at the joint point at the other end of the joint rod (10). 5. Drive device according to claim 4, characterized in that the slide stone (13a) sits on a screw spindle (13b) which extends essentially along the slide path (13c) and is pivotably supported at one end of the slide path (13c). 6. Drive device according to one of claims 1-5, with a lower and an upper support beam, characterized by that both support beams (5, 6) are force-lockingly connected to the lifter (9), whereby the force-locking connection between the upper support beam (6) and the lifter (9) can optionally be switched to counter-stroke operation with the lower support beam (5) or to stationary upper support beam (6) . 7. Drive device according to claim 6, characterized in that the shaft (21) which carries the lifter (9) comprises at least one crank pin (31) which is assigned to a pin (32) which is axially similar to the shaft (21), whereby at least one, preferably two lifting rods (12) which carry the upper support beam (6) each with an eye (33) arranged at its lower end can optionally be attached to the crank pin (31) or to the axle pin (32). 8. Drive device according to one of claims 1-7, characterized in that the lifter (9) is formed by a first lifting arm (37) attached to the lifting shaft (21), over the connecting rod (10) force-locking with the follower (2) and two or more on the lifting shaft (21) fixed, above each lifting piston (11) with the support beam (5) other lifting arms (38) connected forcefully.