FORWARD FEED SUPPLY DEVICE FOR A BAND MATERIAL

Description

CROSS-REFERENCE TO RELATED APPLICATION

This patent application claims the priority benefits of German patent application No. 10 2024 119 652.1 filed Jul. 10, 2024. The said German patent application No. 10 2024 119 652.1 is incorporated herein by reference in its entirety as though fully set forth.

BACKGROUND OF THE INVENTION

The invention relates to a forward feed supply device configured to feed a band material in a feeding direction by supplying a thrust force. The band material is stiff in feeding direction and it particularly does not bend when applying a thrust force in feeding direction. It can be a metallic material, a plastic material or a composite material.

For example, a forward feed supply device is used to feed band material toward a processing machine, particularly a cyclically operating processing machine, for example a forming and/or stamping machine. In the processing machine, in each cycle, at least one workpiece can be manufactured from the supplied band material, wherein the production can be an arbitrary processing, for example separating and/or cutting and/or stamping and/or forming and/or embossing.

A forward feed supply device is described in DE 10 2010 060 461 A1, for example. The forward feed supply device has two drums between which the band material is passed through. One of the two drums can be driven by means of a drive unit, if the band material shall be fed in a feeding direction.

With very high widths of the band material in a transverse direction orthogonal to the feeding direction, the problem exists that respectively long drums can bend due to their own weight or due to an externally applied pressing force, for example in case of widths of more than 1.5 m. Such a bending of the drums can result in that they wear non-uniformly and along the drum width locally different wear effects occur. Particularly in case of drums having a plastic coating for smooth feeding of the fed band material, in turn, a non-uniform forward feeding of the band material can occur, for example if remarkably different slip between the drums and the band material occurs in transverse direction. Therefrom, in turn, disturbances in the subsequent processing operation of the band material may result.

Also, frequently, the pressing force varies remarkably in case of very long drums for feeding of wide band material. With view in transverse direction in the area of the bearing of the drum, the pressing force against the band material is higher than in a center area between the drum bearings.

In order to encounter the bending of drums, drums can be carried out in a cambered manner so that the drum diameter increases toward the drum center (compare for example DE 196 36 184 A1). The manufacturing of such drums is, however, complex and expensive.

As an alternative DE 196 36 184 A1 proposes to apply a counter-bending torque by means of the drum bearing, which however also requires increased efforts for the bearing of the drum.

Starting from the prior art it can be considered as object of the present invention to provide a forward feed supply device that guarantees a reliable and uniform feeding of a band material in feeding direction and allows a flexible use.

SUMMARY OF THE INVENTION

This object is solved by means of a forward feed supply device having the features of claim 1.

The forward feed supply device according to the present invention is configured to feed band material in a feeding direction by applying a thrust force in the feeding direction. The band material is stiff in the feeding direction and particularly does not bend under the thrust force applied in the feeding direction. For example, the forward feed supply device serves to feed band material to a processing machine, particularly a cyclically operating processing machine, such as a stamping machine and/or a forming machine. In the processing machine the band material can be processed in each cycle and thereby at least one workpiece can be produced, for example by means of stamping and/or cutting and/or forming and/or embossing. The produced workpieces can be an intermediate or a final product.

In general, the band material can consist of an arbitrary material, for example, of a metallic alloy, a plastic or a composite material. A width of the band material in a transverse direction, orientated orthogonal to the feeding direction, can be minimum 1.5 m, for example.

Preferably, the band material is at least substantially horizontally arranged in the forward feed supply device. The feeding direction and the transverse direction are then orientated horizontally.

The forward feed supply device comprises a forward feed drum, rotatingly supported around a drum axis. The drum axis extends in a transverse direction, orientated orthogonal to the feeding direction. Preferably, the drum axis is orientated horizontally. The forward feed drum can be rotatingly driven around the drum axis by means of a drive unit, for example, in a stepwise manner.

The forward feed drum comprises a drum contact surface extending in circumferential direction around the drum axis. The drum contact surface is particularly a cylinder jacket surface. The band material to be fed abuts against the drum contact surface. Particularly, the band material is arranged on top of the forward feed drum.

Adjacent to the forward feed drum, multiple pressing units are present. The number of pressing units can vary depending on the maximum width of the band material to be supplied, depending on the specific application. With view in transverse direction in an embodiment, one pressing unit can be present all 20 to 30 cm. In doing so, it is guaranteed that the distance between the pressing units in transverse direction is sufficiently small.

Each pressing unit is configured to press at least one pressing roller or at least one other pressing body with a defined pressing force against the band material. The band material is thereby arranged between the pressing roller or the pressing body and the drum contact surface of the forward feed drum. The pressing force is locally applied by means of each pressing unit at an assigned pressing position with view in transverse direction onto the band material to be fed. The direction of the pressing force is orthogonal and particularly radial relative to the drum axis of the forward feed drum. The pressing forces can be applied onto the band material in vertical direction.

Due to using multiple individual pressing units, the pressing force can be specifically adapted or adjusted in transverse direction over the entire width of the band material. The pressing bodies of the multiple pressing units are not immovably coupled with one another, so that the relative position and/or relative movement between the forward feed drum and each of the present pressing bodies can be individually set. In doing so, also the possibility is provided to control in open or closed loop manner and/or to correct and/or to predefine the pressing force of each provided pressing unit or pressing body individually. Thereby, a uniform wear of the forward feed drum over its entire width and a reliable uniform feeding of the band material in feeding direction can be achieved. In addition, the possibility is provided to consider influences during the operation, such as changes due to thermal influences, wear occurring over time, etc.

The forward feed supply device is particularly configured to operate in a clocked manner. During one single clock period or cycle, the forward feed drum is rotatingly driven around the drum axis during a feed phase and stands still during a rest phase. The feed phase and the rest phase can have equal or different durations, which depends on the following processing operation of the band material.

It is advantageous if the forward feed supply device comprises at least one sensor that produces a sensor value characterizing the orientation of the band material relative to the feeding direction, wherein the sensor value is provided to the control device of the forward feed supply device. In doing so, the band orientation can be monitored, so-to-speak, and can be considered during control of the pressing units.

The forward feed supply device comprises a control device. The control device is configured to control the pressing units and preferably, additionally, the drive unit for driving the forward feed drum.

The pressing force of each pressing unit can be controlled in open-loop manner or can be controlled in closed-loop manner. One, multiple or all pressing units can be open-loop or closed-loop controlled so that all pressing forces have equal amounts. In a preferred embodiment, it is also possible to individually control one, multiple or all pressing units individually in open-loop or closed-loop manner so that the pressing forces of at least two of the present pressing units that are currently used for feeding the band material can have different amounts. The pressing force of one, multiple or all pressing units can be also equal to zero at least during phases, for example during phases in which the forward feed drum is not rotatingly driven around the drum axis. As another example, during set-up of the forward feed supply device and/or the processing machine, the pressing units can be controlled so that the pressing bodies or pressing rollers are lifted, whereby a gap is created between the pressing bodies or pressing rollers on one side and the drum contact surface of the forward feed drum on the other side, which is preferably at least as large or larger than the thickness of the band material. In doing so, insertion of the band material into the gap between the pressing bodies or pressing rollers and the forward feed drum is simplified. During such a set-up, independent from whether the pressing bodies or rollers are displaced from the inserted band material or in contact with the inserted band material, particularly no pressing force is applied onto the band material by means of the pressing units.

In general, the pressing force of one single pressing unit, of multiple or all provided pressing units can vary over time (e.g. in subsequent phases, such as set-up phase, supply phase and rest phase or also for compensating external influences during one or more phases).

As explained, the pressing force of all pressing units can be equal or the pressing force of at least two of the present pressing units can be different at least temporarily and/or during phases. Depending on the determined operating condition, therefore, the pressing force in all pressing units can be at least temporarily and/or during phases equal or different. Thereby, it is in turn possible to set the pressing forces with view in transverse direction in a manner, so that they increase continuously or decrease continuously. It can also be advantageous to divide the provided pressing units in two or more groups and to set the pressing forces within one common group so that they are equal and to set the pressing forces of different groups so that they have different amounts.

For example, if it has been determined that the band material is obliquely orientated relative to the feeding direction between the pressing units and the forward feed drum, the pressing forces with view in transverse direction can be set to have different amounts at different pressing units in order to influence the forward feed movement in feeding direction and to counteract the oblique orientation of the band material. With view in transverse direction, the band material can thus be moved about different amounts in feeding direction during rotation of the forward feed drum so that the orientation of the band material is again coinciding with the feeding direction with sufficient accuracy.

In a preferred embodiment, the pressing units can be controlled in a manner so that multiple or all pressing units have a pressing force equal to zero at least during phases or temporarily during one cycle, or that they are lifted from the band material so that a gap is created between the at least one lifted pressing body or pressing roller and the band material. In such a situation or during such a phase, the band material can be moved with a comparable low force in transverse direction relative to the forward feed drum or the drum contact surface.

For example, due to reducing the pressing forces (for example during a rest phase of the forward feed drum or during setup), wear in the processing machine or in a tool of the processing machine can be reduced to which the band material is supplied by means of the forward feed supply device. For example, if the band material is curved in its longitudinal extension (also denoted as “saber-shaped” band material) or is for other reasons not orientated in feeding direction, the guides in the processing machine or a tool of the processing machine can be highly stressed. This is because due to clamping of the band material in the forward feed supply device, a transverse force can be transmitted via the band material into a guide device for the band material of the processing machine. By means of reducing or eliminating the pressing forces of one or more pressing units temporarily or during at least one phase (e.g. lifting of the pressing bodies), the insertion of such transverse forces into the guide device for the band material within the processing machine can be at least reduced.

In a preferred embodiment, each pressing unit comprises at least one pressing roller, rotatingly supported around a roller axis, wherein the pressing roller serves as pressing body. The roller axis extends preferably in transverse direction and is thus parallel to the drum axis. Preferably, all of the roller axes can be arranged along one single common straight line. As an option, the roller axes can be offset in a circumferential direction around the drum axis relative to one another. Each pressing roller can have a roller contact surface particularly corresponding to the jacket surface of a cylinder.

The roller contact surface and/or the drum contact surface can consist of plastic. For example, the roller contact surface and/or the drum contact surface can be formed by means of a plastic layer or a coating layer. A core of the forward feed drum and/or the pressing roller can in this case consist of a metallic material or another arbitrary material. The roller contact surface and/or the drum contact surface consists of polyurethane in one embodiment.

In the preferred embodiments, the pressing units do not comprise a drive by means of which the pressing rollers could be driven. The pressing rollers of the pressing unit are not actively drivable, so-to-speak, but can be rotated only passively due to an external influence. A pressing roller rotates around its roller axis if the pressing roller abuts in a friction-fit manner against the band material and the band material is moved in feeding direction.

The direction in which one or more or all pressing units create a pressing force can be denoted as pressing direction. The pressing direction is preferably orientated vertically.

Preferably, all of the pressing rollers are movably supported and/or spring elastically supported in pressing direction. The movability in pressing direction is achieved in a preferred embodiment, in that the pressing unit comprises a controllable actuator device, for example a fluid cylinder. A spring elastic support can be achieved by means of a mechanical spring device and/or a gas spring device.

Each pressing unit can have an actuator device controllable by means of the control unit. The actuator device is particularly configured to set the relative movement and/or relative position of the respective pressing body (for example pressing roller) relative to the forward feed drum and/or to set the pressing force. In doing so, for example, a distance between the pressing body and the drum contact surface can be adjusted. This distance can be adapted to the material thickness of the band material and/or can be varied depending on the current operating phase or operating condition of the forward feed supply device (for example setup condition and/or feed phase and/or rest phase).

The actuator devices can also be controlled so that disturbing influences occurring during operation, such as deformations on a support device for the actuator devices due to applied forces and/or wear of the pressing bodies and/or wear of the forward feed drum can be compensated automatically, at least partly. For example, during a feed phase (rotation of the forward feed drum) the pressing forces of all pressing units occurring between the respective pressing body, the band material and the drum contact surface can be set or controlled to have equal absolute values in order to provide a uniform slippage and/or wear over the entire width of the forward feed drum. As another example, if during a feed phase an orientation of the band material relative to the feeding direction shall be corrected, the pressing forces of the pressing units can be set or controlled to have absolute values increasing from one side to the other side with view in transverse direction.

The actuator device can be configured as double-acting actuator device. This means an actuator device that can create a force and/or a movement in two opposite directions onto the at least one assigned pressing body. For example, in doing so, the at least one pressing body can be pressed with a defined pressing force against the band material or can also be lifted from the band material.

The actuator device of each pressing unit can comprise a fluid cylinder, for example, particularly a pneumatic cylinder. The fluid cylinder can be a single acting cylinder or a double acting cylinder. In the configuration as pneumatic cylinder, also a spring effect can be achieved if the at least one pressing body or the at least one pressing roller is pressed against the band material.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantageous configurations of the invention are derived from the dependent claims, the description and the drawings. In the following, preferred embodiments of the invention are explained in detail based on the attached drawings. The drawings show:

FIG. 1 a schematic block diagram-like illustration of an embodiment of the forward feed supply device in a view in feeding direction of band material,

FIG. 2 a schematic simplified illustration in part of the embodiment of the forward feed supply device of FIG. 1, as well as a processing machine to which the band material is supplied in feeding direction by means of the forward feed supply device,

FIG. 3 a schematic block diagram-like illustration of an embodiment of a pressing unit of the forward feed supply device according to FIGS. 1 and 2,

FIG. 4 a cross-section illustration of an embodiment of the pressing unit of FIG. 3 in a cross-sectional plane orthogonal to the feeding direction,

FIG. 5 a cross-section illustration of an embodiment of the pressing unit of FIG. 4 in a cross-sectional plane orthogonal to a transverse direction, and

FIG. 6 a schematic exemplary time-dependent progress of a clocked or cyclic supply of band material by means of the forward feed supply device.

DETAILED DESCRIPTION OF THE INVENTION

In FIG. 1 an embodiment of a forward feed supply device 10 is illustrated highly schematically, in the type of a block diagram. The forward feed supply device 10 is configured to feed band material 11 in a feeding direction R by means of applying a thrust force S onto the band material 11 (FIG. 2). For example, the band material 11 can be taken from and particularly wound from a supply, for example a band supply roll, as continuous material.

For example, the forward feed supply device 10 is configured to supply the band material 11 in feeding direction R to a processing machine, for which the band material 11 serves as initial material. In the present embodiment the processing machine 12 is a cyclically operating machine, for example a stamping and/or forming machine. In the processing machine 12 band material 11 can be processed by means of cutting, stamping, separating, forming, embossing, or an arbitrary combination thereof, so that in each cycle one or more workpieces 13 can be produced from the band material 11. The workpiece 13 can be an end product or intermediate product.

If the processing machine 12 operates cyclically, the forward feed supply device 10 is preferably configured to feed the band material 11 in a cyclic or clocked manner. For this purpose, the band material 11 can be moved during a feed phase PF in feeding direction R and can remain immovably in feeding direction R during a following rest phase PS. One single feed phase PF and one single rest phase PS are comprised in one single cycle or clock period respectively, wherein the cycle or clock period has a cycle or clock time T (compare FIG. 6).

The forward feed supply device 10 comprises a forward feed drum 16 that is rotatingly supported around a drum axis W. The drum axis W extends in a transverse direction Q. The transverse direction Q is in turn orientated orthogonal to the feeding direction R of the band material 11, which is particularly apparent from FIG. 2.

A drive unit 17 is coupled with forward feed drum 16 (FIG. 1). The drive unit 17 is configured to rotatingly drive the forward feed drum 16 during a feed phase PF around drum axis W. The drive unit 17 can comprise an electric motor, for example.

The forward feed drum 16 comprises a drum contact surface 18 at its circumference. In the embodiment the drum contact surface 18 has the shape of a cylinder jacket surface. The band material 11 abuts against drum contact surface 18 in friction-fit manner. During a rotation of the forward feed drum 16 around the rotation axis W, band material 11 is moved in feeding direction due to the friction-fit contact with the drum contact surface 18 and is supplied toward the processing machine 12, according to the example.

In order to maintain the friction-fit contact between the drum contact surface 18 and the band material 11, the forward feed supply device 10 comprises multiple pressing units 19. In transverse direction Q, pressing units 19 are arranged next to one another and preferably with distance to one another. Each pressing unit 19 is configured to create a pressing force F in a pressing direction Z, wherein the pressing force F is orientated radially relative to the drum axis W in the embodiment. The pressing direction Z is preferably orientated vertically. The pressing force F acts between the pressing unit 19 and the band material 11 in order to press the band material 11 against the drum contact surface 18 of the forward feed drum 16. The pressing force F of each pressing unit 19 acts locally onto the band material 11 at one assigned position in transverse direction Q, as schematically apparent from FIG. 1.

In order to create the pressing force F onto the band material 11, each pressing unit 19 comprises a pressing body that is preferably configured as pressing roller 20. The at least one pressing roller 20 is rotatingly supported around a roller axis A of pressing unit 19 (FIG. 3). The at least one pressing roller 20 is not actively driven by means of a drive of the pressing unit 19. Rather, the pressing units 19 are realized without roller drive. The at least one pressing roller 20 only rotates passively, so-to-speak, if it is subject to a rotation torque, for example, if it contacts band material 11 in friction-fit manner and band material is moved in feeding direction R.

For example, each pressing unit 19 can have one single pressing roller (FIGS. 1 to 3) or two pressing rollers 20 (FIGS. 4 and 5). The roller axis A of each pressing unit 19 extends in transverse direction Q. All of the roller axes A of the pressing units 19 can be arranged along a common straight line and/or arranged in a common plane, but could alternatively to this also be offset in circumferential direction around drum axis W relative to one another.

Each pressing roller 20 has a roller contact surface 21. The roller contact surface 21 is provided on a circumferential surface extending around the roller axis A of the pressing roller 20. The roller contact surface 21 corresponds to the jacket surface of a cylinder analog to the drum contact surface 18. The pressing roller 20 can be cylindrically shaped, at least substantially.

In the embodiment the drum contact surface 18 and/or the roller contact surfaces 21 are made of plastic, for example polyurethane. For example, it is possible to provide a drum core 16a or roller core 20a with a hollow cylindrical jacket of plastic (for example polyurethane) that in this manner forms a drum jacket 16b or roller jacket 20b (FIG. 4). The cores 16a, 20a can be made of an arbitrary other material, particularly consist of a material having higher hardness than the respective jacket 16b, 20b.

The pressing force F can be individually set or adjusted for all present pressing units 19. Alternatively, the pressing units 19 can be divided in multiple groups, wherein the pressing forces F of different groups can have different amounts, however the pressing forces of the pressing units 19 of each common group have equal amounts. It is, however, preferred if the pressing forces for each pressing unit 19 can be individually set, for example by means of a control device 25. In the embodiment control device 25 is also configured to control the drive unit 17. The control of the pressing units 19 and the drive unit 17 using control device 25 is highly schematically illustrated in FIG. 1 by means of dashed arrows. The control can be respectively realized as direct control, preferably by means of an electrical control signal or indirect control via intermediate devices, such as converters.

The pressing forces F of pressing units 19 can be set to have equal amounts, so that the band material 11 is pressed with the same pressing force F against the drum contact surface 18 at each position with view in transverse direction Q at which one of the pressing rollers 20 abuts against the band material 11. Additionally or alternatively, it is also possible to adjust the pressing forces F for different pressing units 19, so as to have different amounts. In doing so, a slip between the forward feed drum 16 and the band material 11 in transverse direction Q can be varied, for example. In such a case, the thrust force S acting in feeding direction R applied onto the band material 11 by means of the forward feed supply device 10 can be different at different positions with view in transverse direction Q, as schematically illustrated in FIG. 2. This can be used, for example, to additionally create a force onto the band material 11 acting in transverse direction Q, if advantageous in specific operating conditions. For example, if it is determined that the longitudinal edges of band material 11 are orientated obliquely relative to the feeding direction R (schematically illustrated in FIG. 2 by dashed lines), this oblique orientation can be reduced or counteracted by means of thrust forces S having different amounts. Such thrust forces S with different absolute values at different positions with view in transverse direction Q can be realized due to different pressing forces F, which result in different slip between the band material 11 and the forward feed drum.

For monitoring the orientation of the band material 11 in feeding direction R, the forward feed supply device 10 can comprise at least one monitoring sensor 24. In the embodiment schematically illustrated in FIG. 1, two monitoring sensors 24 are provided. Each monitoring sensor 24 can be assigned to a longitudinal edge of band material 11 extending parallel to feeding direction R if orientated correctly. Each monitoring sensor 24 creates a monitoring sensor value U1, U2, that is provided to control device 25, for example.

The control device 25 can control the pressing units 19 depending on the at least one monitoring sensor value U1, U2, for example in order to set the pressing forces F of one, multiple or all present pressing units 19 used for feeding the band material 11 based on the at least one monitoring sensor value U1, U2. For example, by means of the at least one monitoring sensor value U1, U2 the correct orientation of band material 11 relative to feeding direction R can be monitored and in case of an oblique orientation, the oblique orientation of band material 11 can be counteracted or reduced, as explained above based on FIG. 2, by means of adapting one or more pressing forces F and the resulting modified thrust force distribution in transverse direction Q.

FIG. 3 is a block diagram of an embodiment of a pressing unit 19. Preferably, all of the present pressing units 19 are configured identically. It is thus sufficient to explain the function of one single pressing unit 19, exemplarily for all provided pressing units 19.

For setting the pressing force F and/or the relative position of pressing roller 20 relative to the forward feed drum 16, pressing unit 19 has an actuator device 26. The actuator device 26 comprises a fluid cylinder 27 and preferably a double-acting fluid cylinder according to the embodiment. The fluid cylinder 27 is preferably configured as pneumatic cylinder 28. The fluid cylinder 27 or pneumatic cylinder 28 comprises a first cylinder chamber 29 and a second cylinder chamber 30 in the preferred embodiment. The two cylinder chambers 29, 30 are fluidically separated from one another by means of a piston 31 that is displaceably supported inside fluid cylinder 27. The piston 31 is connected to a piston rod 32 extending from a housing of the fluid cylinder 27 or pneumatic cylinder 28. On the outer free end of piston rod 32 a roller holder for the at least one pressing roller 20 is attached. For example, the roller holder comprises an axle pin 33 on which the at least one pressing roller 20 is rotatingly supported around roller axis A.

A first fluid line 34 is connected to first cylinder chamber 29 and a second fluid line 35 is connected to second cylinder chamber 30. The two fluid lines 34, 35, are connected with a valve unit 36, which is part of the actuator device 26 in the embodiment. The fluid (for example pressurized air) can be supplied to first cylinder chamber 29 or second cylinder chamber 30 by means of valve unit 36. From the respectively other cylinder chamber 29, 30, fluid can be discharged. For example, one of the two cylinder chambers 29, 30 can be connected to a fluid pressure source 37, while the respectively other cylinder chamber 30 or 29 can be connected to a fluid pressure sink 38. A pressure medium reservoir or tank can serve as fluid pressure sink 38, particularly if the fluid is a liquid or is a gas that cannot be discharged into the environment. If air is used as a fluid, the fluid pressure sink 38 can be realized as a discharge into the environment. The fluid pressure source 37 can provide fluid under a predefined pressure. The pressure within cylinder chambers 29, 30 can be controlled by means of valve unit 36, for example up to the pressure provided by the fluid pressure source 37.

The configuration of the valve unit 36 can be arbitrary. Only by way of example, FIG. 3 shows a directional control valve that can be switched between at least two switching conditions.

If in the embodiment, first cylinder chamber 29 is pressurized, an outward movement of piston 31 and piston rod 32 can be carried out, at least until pressing roller 20 abuts against band material 11. Upon this point in time, the pressure control inside fluid cylinder 27 or pneumatic cylinder 28 and particularly the pressure setting in first cylinder chamber 29, can be used to control the pressing force F of the at least one pressing roller 20 against band material 11. The pressing force F can be open-loop or closed-loop controlled.

For example, it is possible to assign a pressure sensor 39 at least to the first cylinder chamber 29 or alternatively to both cylinder chambers 29, 30 in order to measure the pressure in the respective cylinder chamber 29 or 30 and to provide a respective measurement value M to control unit 25. Control unit 25 can control valve unit 36 by means of a respective valve control signal V, depending on measurement value M, so that indirectly by means of the pressure inside pressure chamber 29, 30 the desired pressing force F is created.

The measurement value M is characterizing pressing force F. It is clear that pressing force F could also be directly sensored or indirectly determined in another manner, for example by means of a force sensor at a suitable position within the force path, for example, on the piston rod 32, the roller holder, the axle pin 33, etc.

In FIGS. 4 and 5 an embodiment of the pressing unit 19 is illustrated in cross-section respectively, wherein FIG. 4 shows a cross-section orthogonal to the feeding direction R and FIG. 5 shows a cross-section orthogonal to transverse direction Q. In this embodiment pressing unit 19 has two pressing rollers 20 different to the embodiment according to FIGS. 1, 2, 3 described so far, wherein the two pressing rollers 20 are arranged on a common roller holder. Here, one axle pin 33 serves as roller holder for the two pressing rollers 20, wherein axle pin 33 is attached to the free outer end of piston rod 32. The two pressing rollers 20 are thereby rotatingly supported on axle pin 33, for example by means of a roller bearing arrangement 40.

The actuator device 26 can be realized according to the embodiment of FIG. 3, so that reference can be made to the description above.

In the embodiment fluid cylinders 27 or pneumatic cylinders 28 are attached to a common support device comprising an upper flange 45 and a bridge 46 (FIGS. 4 and 5). The cylinder housings of fluid cylinders 27 or pneumatic cylinders 28 are held between upper flange 45 and bridge 46 according to the example. With the piston rod 32 being extended, piston 31 is positioned so that second cylinder chamber 30 has a minimum size G in direction parallel to piston rod 32, wherein the minimum size G is always larger than zero (G>0). Thereby advantages with regard to the creation of the pressing forces F of individual pressing units 19 result. For example, bending of bridge 46 can be at least partly compensated, particularly automatically. Additionally or alternatively, also wear of the pressing rollers 20 and/or the forward feed drum 16 (for example, wear of the roller jackets 20b and/or the drum jackets 16b) can be compensated at least partly, particularly automatically.

As apparent from FIG. 5, the at least one pressing roller 20 of each pressing unit 19 can be guided by means of a guide device 47 orthogonal to transverse direction Q or radial to drum axis W in addition to the guidance provided by piston rod 32, which is supported inside fluid cylinder 27 or pneumatic cylinder 28 in guided manner. Forces acting in feeding direction R and/or in transverse direction Q onto the pressing rollers 20 can be supported additionally in order to relieve piston rod 32 and/or piston 31.

In the embodiment guide device 47 comprises at least one guide column 48 connected with a housing of fluid cylinder 27 or pneumatic cylinder 28, wherein the guide column extends parallel to piston rod 32 in pressing direction Z. The at least one guide column 48 is arranged with distance to piston rod 32. In the embodiment, two guiding columns 48 are provided, which are arranged in feeding direction R with distance to one another, wherein piston rod 32 is arranged between the two guiding columns 48 in feeding direction R.

A guide part 49 is moveably supported in extension direction of the guiding columns 48 on the guiding columns 48. For this purpose, a guide bushing 50 can be provided in the guide part 49 for each guide column 48. The guide bushing 50 can be a sliding guide bushing or a roller body guide bushing having roller bodies (for example, ball guide bushing with balls). The roller holder or axle pin 33 is attached to guide part 49 so that forces acting in feeding direction R and/or in transverse direction Q on the at least one pressing roller 20 are at least partly supported by or introduced into the housing of fluid cylinder 27 or pneumatic cylinder 28 via guide part 49 and via the at least one guide column 48. In doing so, guidance of the piston rod 32 and piston 31 inside fluid cylinder 27 or pneumatic cylinder 28 is relieved from stress. In addition, band material 11 is positioned precisely and with low play or without play in feeding direction R.

Based on FIGS. 1 and 5 another optional configuration of forward feed supply device 10 is apparent. The forward feed drum 16 can be supported at one or more positions with view in transverse direction Q by means of at least one support roller arrangement 55. The support roller arrangement 55 can have multiple support rollers 56 abutting against drum contact surface 18. Each support roller 56 is rotatably supported around a rotation axis extending parallel to drum axis W in transverse direction Q. As apparent from FIG. 5, on both sides of roller axis W in feeding direction R, one support roller 56 can be arranged respectively and can together form a support roller pair 57. The support roller arrangement 55 can have more than one support roller pair 57 arranged in transverse direction Q next to one another. At each support position of forward feed drum 16 at least one support roller pair 57 can be present.

The support roller arrangement 55 is configured to avoid bending of forward feed drum 16 or to counteract such bending or slacking. In doing so, drum axis W shall be maintained in a straight orientation in transverse direction Q.

For optimization of the support of forward feed drum 16 and/or for adoption to changes due to external influences (for example thermal influences, wear, etc.), the distance of support rollers 56 in feeding direction R of a common support roller pair 57 can be adjusted manually and/or automatically. For example, for this purpose, a spindle unit 58 can be used that can be operated automatically or manually by using a tool. The spindle unit 58 can move the two support rollers 56 of the common support roller pair 57 toward one another or away from one another, similar to a bench vice, wherein each support roller 56 preferably moves about the same length in feeding direction R relative to a central plane extending between the two support rollers 56 and comprising the drum axis W.

Based on the time diagrams in FIG. 6, a clocked feeding of band material 11 in feeding direction R is explained by way of example. The illustrations in FIG. 6 are only schematical for the purpose of explanation. By way of example, FIG. 6 shows the pressing force F depending on the time t as well as a rotation movement D of forward feed drum 16 around drum axis W depending on time t. The time-dependent signals are illustrated only qualitatively, but not quantitatively. The absolute value of the pressing forces F of different pressing units 19 can be equal or can be different independent from the time-dependent progress explained based on FIG. 6 in the following:

At a first point in time t1, a cycle or operating clock period having a cycle or clock time T begins. First, a pressing force F is created onto the band material 11 by means of pressing units 19. When pressing force F is sufficiently large and thus a friction force connection of band material 11 to forward feed drum 16 is established, forward feed drum 16 is rotatingly driven around drum axis W by means of drive unit 17 (second point in time t2).

At a third point in time t3, band material 11 has been sufficiently moved in feeding direction R and the rotating movement D of forward feed drum 16 is stopped. The phase from the second point in time t2 to the third point in time t3 is the feed phase PF during this operation clock period or cycle.

A rest phase PS follows the feed phase PF at the third point in time t3, whereby the forward feed drum 16 stands still during the rest phase PF and does not carry out a rotation movement D around drum axis W.

After stopping the rotation movement D at the third point in time t3, pressing force F can be reduced if necessary or desired, for example can be completely cancelled (pressing force F=0). At a fourth point in time t4, pressing force F reaches the reduced (minimum) value and can be equal to zero. In this condition the roller contact surfaces 21 can still be in contact with band material 11 or can be lifted from band material 11 by means of actuator device 26 of the respective pressing unit 19.

Preferably after the fourth point in time t4, band material 11 is processed in the processing machine 12. Because band material 11 is in this phase not clamped or clamped with reduced clamping force in transverse direction Q by means of forward feed device 10, but is only held in transverse direction Q with comparable small friction forces, a movement or orientation of band material 11 in transverse direction Q is allowed inside the processing machine 12. Wear occurring in the processing machine 12 is reduced thereby, for example on guide devices of the processing machine 12 and/or a tool used in the processing machine 12.

At a fifth point in time t5, processing of band material 11 is finished in this cycle and a new clock period a new cycle starts that progresses analog to the clock period or cycle described above (points in time t1 to t5).

In modification to the illustration in FIG. 6, pressing force F can also be maintained continuously by means of the pressing units 19 used for supply of band material 11 and can be constant for all used pressing units 19.

As already explained, pressing force F of each pressing unit 19 can also be individually set and can be different from a pressing force F in one other, multiple other or all other pressing units 19.

In all embodiments actuator device 26 can also be realized by a motor-spindle-device or a pinion rod drive or another known motor device different to the illustrated preferred embodiment.

If actuator device 26 comprises a pneumatic cylinder 28, a spring support of piston 31 and thus piston rod 32 and thereby in turn the at least one pressing roller 20 can be achieved due to the compressible gas inside cylinder chambers 29, 30. For example, in this manner corrugations or other deviations of band material 11 can be balanced. Such a spring support can optionally also be achieved by means of a spring arrangement having at least one helical spring and/or at least one disc spring at which the at least one pressing roller 20 is supported, for example by means of a rod that is movably supported in pressing direction Z of the pressing force F instead of piston rod 32. By means of an adjustment drive (for example motor-spindle-unit) the compression of the spring arrangement can be varied and thus the pressing force F can be adjusted or set.

The invention refers to a forward feed supply device 10 for feeding band material 11 in a feeding direction R. For this purpose, band material 11 is in contact with a drum contact surface 18 of a forward feed drum 16. The drum contact surface 18 corresponds particularly to the circumferential jacket of a cylinder and can be a plastic surface, consisting for example of polyurethane. The forward feed drum 16 can be rotatingly driven around a drum axis W by means of a drive unit 17. The drum axis W extends thereby in a transverse direction Q orientated orthogonal to feeding direction R. Multiple pressing units 19 are arranged next to one another in transverse direction Q and press the band material 11 with a defined pressing force F against drum contact surface 18. For this purpose, each pressing unit 19 can comprise a pressing roller 20, for example. The pressing roller 20 has a roller contact surface 21 that can be a plastic surface analog to the drum contact surface 18, for example made from polyurethane. For control of the pressing units 19 and/or the drive unit 17 the forward feed supply device 10 can comprise a control device 25.

LIST OF REFERENCE SIGNS

• • 10 forward feed supply device
  • 11 band material
  • 12 processing machine
  • 13 workpiece
  • 16 forward feed drum
  • 16a drum core
  • 16b drum jacket
  • 17 drive unit
  • 18 drum contact surface
  • 19 pressing unit
  • 20 pressing roller
  • 20a roller core
  • 20b roller jacket
  • 21 roller contact surface
  • 24 monitoring sensor
  • 25 control device
  • 26 actuator device
  • 27 fluid cylinder
  • 28 pneumatic cylinder
  • 29 first cylinder chamber
  • 30 second cylinder chamber
  • 31 piston
  • 32 piston rod
  • 33 axle pin
  • 34 first fluid line
  • 35 second fluid line
  • 36 valve unit
  • 37 fluid pressure source
  • 38 fluid pressure sink
  • 39 pressure sensor
  • 40 roller bearing arrangement
  • 45 top flange
  • 46 bridge
  • 47 guide device
  • 48 guide column
  • 49 guide part
  • 50 guide bushing
  • 55 support roller arrangement
  • 56 support roller
  • 57 support roller pair
  • 58 spindle unit
  • A roller axis
  • D rotation movement of forward feed drum
  • F pressing force
  • G minimum size of second cylinder chamber
  • M measurement value
  • Q transverse direction
  • PF feed phase
  • PS rest phase
  • R feeding direction
  • S thrust force
  • t time
  • t1 first point in time
  • t2 second point in time
  • t3 third point in time
  • t4 fourth point in time
  • T cycle or clock time
  • U monitoring sensor value
  • V valve control signal
  • W drum axis
  • Z pressing direction