Pressure cylinder for a material conveying device

Abstract

The present invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, comprising: a piston rod configured to engage with a movable component of the material conveying device; a cylinder chamber configured to guide the piston rod at least partially; a piston arranged in the cylinder chamber and connected to the piston rod; wherein the piston rod comprises a first piston rod element and a second piston rod element configured such that a rotary movement of the first piston rod element causes a translational movement of the second piston rod element relative to the piston; wherein the first piston rod element is rotatably arranged relative to the piston.

Description

1. Technical area

[0001] The present invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, wherein the pressure cylinder comprises a piston rod, wherein the length of the piston rod is adjustable.

[0002] The present invention also relates to a material conveying device comprising at least one corresponding pressure cylinder, as well as a method for adjusting a length of a piston rod of a pressure cylinder. 2 . State of the art

[0003] Material conveying devices, especially roller feeds, are used, for example, for conveying and feeding workpieces, such as strip material or coil material, in a timed manner. Roller feeds are used, for example, in punching applications. The workpiece is fed in a timed manner, with the feed timing synchronized with a punching tool.

[0004] Roller feeds are also known from other applications. For example, a roller feed may have a profiled roller and, as the workpiece is advanced, emboss or punch the corresponding profile into the workpiece.

[0005] The principle of the roller feed is basically based on at least two rollers, of which at least a first roller is arranged on a first side (for example above) of the workpiece to be conveyed and a second roller is arranged on an opposite side (for example below) of the workpiece to be conveyed.

[0006] At least one of the rollers is a driven roller. For feeding / conveying, the workpiece is inserted into a gap formed between the rollers. The workpiece is then advanced / conveyed by synchronous rotation of the rollers. The rotational speed of the rollers determines the conveying or feed rate.

[0007] Material conveying devices usually have pressure cylinders that are intended to fulfill several functions.

[0008] Firstly, pressure cylinders are designed to apply pressure to a roller, for example, the upper roller. This pressure enables the strip material fed into the material conveyor to be transported with as little slippage as possible. Typically, the pressure from the pressure cylinder is applied to a movable rocker, which then transfers the pressure to the roller. The rocker can rotate via a pivot point.

[0009] Pressure cylinders should also be able to raise the roller to allow new strip material to be inserted. This lifting can be achieved, for example, by moving a piston in the cylinder upward, causing the rocker and the upper roller to move upward.

[0010] Pressure cylinders should also allow for intermediate lifting, which can also be referred to as "release." Intermediate lifting causes the roller to lift after each feed cycle of the strip material to release the strip material for a subsequent cutting tool. This allows the subsequent cutting tool, such as a punching tool, to be better centered and aligned with previously punched holes. For example, intermediate lifting allows strip materials to be aligned via pilot pins using pre-punched pilot holes.

[0011] To fulfill the functions described above, a pressure cylinder must meet at least the following requirements. For example, the number of cycles (also called feed cycles) per unit of time represents a significant parameter in material conveying devices. A cycle is the process of raising and lowering the piston in the pressure cylinder (one stroke). The number of cycles per unit of time is also referred to as the cycle rate and is usually expressed as strokes / min. Increased cycle rates can significantly increase the efficiency of material conveying devices. The cycle rates of the pressure cylinder should therefore be increased. Furthermore, a wide variety of different material thicknesses of strip material should be able to be processed. Furthermore, the design should be structurally simple and cost-effective.

[0012] Conventional configurations do not meet this requirement profile. Conventional configurations include, for example, standard pneumatic cylinders or servo motors. Standard pneumatic cylinders usually have a long stroke. This long stroke limits the cycle rates (for example, only 300 strokes / min can be achieved). Due to the long stroke and the associated larger friction surfaces, material wear also has a detrimental effect. This leads to more frequent malfunctions, which is why the configuration is overall cost-intensive. Furthermore, it is not possible to flexibly adapt the cylinder to different strip material thicknesses. Conventional configurations using servo motors allow the position of the rocker to be changed in order to adjust the distance between a roller and the strip material. However, for this purpose, the servo motors are usually attached to the rocker in addition to pressure cylinders.The servo motors thus exert a force opposite to the contact pressure of the contact cylinder. This configuration is therefore highly inefficient, costly, and, due to the additional components, challenging to construct and prone to failure.

[0013] An object of the present invention is therefore to overcome the disadvantages of the prior art. In particular, the present invention is dedicated to the object of providing a pressure cylinder for a material conveying device, wherein the pressure cylinder enables an increased cycle rate. Furthermore, a pressure cylinder is to be provided that is flexibly adjustable in order to be able to process different strip materials in a material conveying device. It is a general object of the invention to provide a pressure cylinder that is structurally simple, enables easier operation and automated adjustment to different strip materials, exhibits little material wear, and is cost-effective. 3. Summary of the invention

[0014] The above objects, as well as further objects that will become apparent from the following description, are achieved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims, and those skilled in the art will find references to other suitable embodiments of the present invention in the disclosure of the present application.

[0015] The aims and objectives of the present invention are achieved, among other things, with a pressure cylinder, a corresponding material conveying device, and a method for adjusting the piston rod length of a pressure cylinder. The technical properties presented below for the pressure cylinder, the advantages of the pressure cylinder, and the improvements over the prior art apply equally to the material conveying device and the method. Pressure cylinder - first piston rod element rotatable to the piston

[0016] A first embodiment of the invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, comprising: a piston rod configured to engage with a movable component of the material conveying device; a cylinder chamber configured to at least partially guide the piston rod; and a piston movably arranged in the cylinder chamber and connected to the piston rod; wherein the piston rod comprises a first piston rod element and a second piston rod element configured such that a rotational movement of the first piston rod element causes a translational movement of the second piston rod element relative to the piston; wherein the first piston rod element is configured to be rotatable relative to the piston.

[0017] The pressure cylinder according to the invention makes it possible to change, in particular adjust, the length of the piston rod. This means that the length of the piston rod is changed relative to the piston. Thus, the length of the piston rod can be adjusted largely independently of the piston's position. This advantageously allows the distance traveled by the piston in the cylinder chamber (stroke length) to be kept short.

[0018] Therefore, the cylinder chamber (also understood as cylinder volume) can be made small. For example, the axial length of the cylinder chamber can be small. This allows the cycle rate (expressed in strokes / min) to be significantly increased compared to the prior art. For example, cycle rates of at least 1000 strokes / min, preferably at least 1500 strokes / min, and most preferably at least 2000 strokes / min can be achieved. This contributes significantly to an increase in the throughput of strip material. Conventional pneumatic pressure cylinders require additional components to limit the stroke length, whereby the piston rod remains unchanged. The cylinder volume of these conventional pressure cylinders remains large, which is disadvantageous and inefficient.

[0019] The pressure cylinder according to the invention can also be flexibly adjusted for different thicknesses of strip material and also provides an increased cycle rate. This ensures overall more efficient processing of strip material in material conveying devices, especially in roller feeds with progressive cutting tools, such as punching tools.

[0020] The engagement of the piston rod with a moving component of the material conveying device can be understood as contact, and in particular, pressure is exerted by the piston rod on the moving component of the material conveying device during operation of the pressure cylinder in order to move the moving component. The "operation" of the pressure cylinder is understood to mean that the piston of the cylinder moves. Thus, intermediate release can be achieved. This "operation" does not necessarily involve the rotational movement of the first piston rod element and / or the translational movement of the second piston rod element relative to the piston. The latter serves to adjust the length of the piston rod. However, it is not excluded that the latter also occurs during operation.

[0021] The cylinder chamber guides the piston rod, at least in part. This can be understood as meaning that the piston rod is at least partially in contact with the cylinder chamber. For example, the piston rod can be guided centrally through the cylinder chamber.

[0022] The piston is typically moved within the cylinder chamber during operation of the pressure cylinder, preferably up and down. Operation can be pneumatic, for example, using compressed air. The piston is connected to the piston rod. This can be understood to mean that the piston rod can also move when the piston moves. The connection is advantageously not a fixed connection that prevents relative movement of the piston and piston rod in all directions (as further explained herein by a rotatable device).

[0023] The rotational movement of the first piston rod element is, for example, a rotational movement about the longitudinal axis of the first piston rod element, preferably about the longitudinal axis of the piston rod.

[0024] The translational movement of the second piston rod element can be understood in particular as a translational movement relative to the first piston rod element.

[0025] The first piston rod element is designed to rotate relative to the piston; this can be achieved, for example, by a bearing. Since the first piston rod element is designed to rotate relative to the piston, the rotational movement of the first piston rod element does not typically result in a rotational movement of the piston. This advantageously prevents the piston from causing frictional forces against a wall of the cylinder chamber (for example, if the piston were to rotate with it). Consequently, the arrangement contributes to low wear and facilitates the adjustment of the piston rod length. The length of the piston rod can therefore be changed without damaging the material, thereby increasing its longevity.

[0026] A second embodiment of the pressure cylinder relates to the previous embodiment, wherein the piston and the first piston rod element are two separate components.

[0027] This allows the piston rod length to be adjusted without affecting the piston, for example, without moving it. If one of the two components should wear, simply replacing the worn component is sufficient. The unworn component can continue to be used. This saves material and reduces costs.

[0028] In this embodiment, the second piston rod element could be moved translationally, in particular without significant effort. The inventors have succeeded in making this possible without significant effort, even when the cylinder chamber is pressurized (i.e., when pressure is exerted on the piston). For example, the pressure cylinder could be pressurized so that the piston is arranged in an upper or lower position within the cylinder chamber. In such a position, the contact area between the piston and a wall of the cylinder chamber can be increased (since, for example, an end face of the piston forms the contact surface in addition to a lateral surface). Consequently, if the piston were to rotate as an integral component with the first piston rod element during a rotational movement of the first piston rod element, the frictional forces would be significantly increased. Accordingly, a significantly increased effort of force would be required.This major disadvantage can be overcome through separation.

[0029] A third embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a threaded rod which is arranged at least partially within the piston rod and which is substantially fixedly connected to the second piston rod element.

[0030] The threaded rod can be understood as a rod, i.e., an elongated component, which has at least a partial thread. The threaded rod can help prevent an unintentional rotational movement of the first piston rod element, as described herein. Thus, an unintentional rotational movement could occur during operation of the pressure cylinder. The fixed connection between the threaded rod and the second piston rod element can be understood in such a way that the connection does not loosen during operation. However, both components can be released using additional means, if desired (e.g., when replacing the components).

[0031] Arranging the threaded rod at least partially within the piston rod saves space and can protect the thread from dirt.

[0032] A fourth embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a releasable locking device arranged substantially in the longitudinal direction of the piston rod at one end of the piston rod and configured to lock an adjustable length of the piston rod; wherein the locking device preferably comprises a screw connection that optionally engages the threaded rod.

[0033] The locking mechanism can, for example, comprise a nut, a lock nut, or a knurled nut. A locking mechanism is to be understood as the securing, locking, and / or blocking of movable components. The locking mechanism is arranged, in particular, at one end of the first piston rod element of the piston rod. This end is typically the end facing away from the movable component of the material conveying device when the pressure cylinder is used in the material conveying device. This arrangement has the advantage, compared to arrangements with lateral locking mechanisms, for example, that the components do not protrude unnecessarily beyond the lateral dimensions. Furthermore, this arrangement enables motorized and / or automated adjustment of the length of the piston rod.

[0034] The locking mechanism can reduce or essentially prevent (unintentional) changes to a set length of the piston rod. Through engagement with the threaded rod, the distance between the locking mechanism and the second piston rod element can be kept essentially constant. In this way, rotational movement of the first piston rod element during operation of the pressure cylinder is advantageously essentially prevented.

[0035] A washer can be arranged between the locking device and the piston rod. The threaded rod can protrude through the washer.

[0036] Preferably, a handwheel can be provided which, when rotated, exerts a correspondingly rectified rotary movement on the first piston rod element. This can facilitate the adjustment of the piston rod length. The connection between the handwheel and the first piston rod element can be made possible via a square connection. Typically, this connection is designed so that when the pressure cylinder is in operation, the handwheel moves translationally together with the piston rod and the piston (e.g. during intermediate release). For this purpose, an air gap can be provided between the handwheel and a wall of an upper cylinder component so that friction losses are largely avoided. The air gap is preferably chosen to be so small that essentially no dirt can get through the air gap. Pressure cylinder - with motor

[0037] A fifth embodiment of the invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, comprising: a piston rod configured to engage with a movable component of the material conveying device; a cylinder chamber configured to at least partially guide the piston rod; a piston arranged in the cylinder chamber and connected to the piston rod; and a motor; wherein the piston rod comprises a first piston rod element and a second piston rod element configured such that a rotational movement of the first piston rod element causes a translational movement of the second piston rod element relative to the piston; wherein the motor is configured to cause the rotational movement of the first piston rod element.

[0038] This embodiment advantageously includes a motor, which allows for optimized adjustment of the piston rod length. Conventional standard pneumatic cylinders do not allow for adjustment of the piston rod length and therefore also do not allow motorized adjustment. The motor enables the sensible integration of a control system. This allows for improved adjustment of the piston rod length when changing the strip material. This also reduces costs by eliminating the need for laborious manual adjustment. A strip material change can be automated. The motor can be an electric motor, for example. It is conceivable to use a servo motor, a stepper motor, or a direct current (DC) motor. The examples of motors listed here are by no means limiting but are intended merely to provide an understanding. A variety of other technically feasible motors can be used.

[0039] In particular, a combination of a motor for adjusting the piston rod length (as described herein) with a pneumatic operation of the pressure cylinder (as described herein) provides significant advantages (as described herein) that do not result from conventional purely pneumatic pressure cylinders or purely electric cylinders.

[0040] A 6th embodiment of the pressure cylinder relates to the previous embodiment, wherein the motor is designed not to cause any translational movement of the first piston rod element.

[0041] The motor need not be required for the operation of the pressure cylinder described herein, especially for intermediate release. Preferably, the pressure cylinder is operated pneumatically, as described herein, thereby achieving, for example, intermediate release. During operation of the pressure cylinder, a translational movement of the first piston rod element therefore occurs. This advantageously does not need to be provided by the motor.

[0042] A 7th embodiment of the pressure cylinder relates to one of the preceding 5th or 6th embodiments, wherein the motor is arranged substantially in the longitudinal direction of the piston rod at one end of the piston rod.

[0043] In one example, the motor could take on the function of a handwheel to adjust a piston rod length.

[0044] An 8th embodiment of the pressure cylinder relates to one of the preceding 5th to 7th embodiments, further comprising: a coupling which is substantially fixedly connected to a motor shaft of the motor, wherein the coupling engages the first piston rod element, preferably via a square connection; wherein the piston rod, in particular the first piston rod element, is configured to be axially movable relative to the coupling; wherein preferably the piston rod, in particular the first piston rod element, is configured to be non-rotatable relative to the coupling.

[0045] The motor can comprise a motor shaft. The motor can further transmit a torque to the coupling, which is then transmitted to the piston rod, in particular only to the first piston rod element and not the second piston rod element. During (pneumatic) operation of the pressure cylinder, the piston rod can move translationally, in particular axially, relative to the coupling and thus relative to the motor. For this purpose, a clearance, such as an air gap, can be provided. The air gap can be large enough to allow the relative translational movement.

[0046] The air gap may be small enough to transmit rotational movement (and torque) of the clutch to the first piston rod element.

[0047] The piston rod, in particular the first piston rod element, is designed to be non-rotatable relative to the coupling. This means that the first piston rod element essentially does not rotate relative to the coupling. Consequently, an (unintentional) change in a set length of the piston rod can be reduced or essentially prevented. In the motorized version, locking by means of a nut, lock nut, or knurled nut is therefore not absolutely necessary.

[0048] A 9th embodiment of the pressure cylinder relates to the previous embodiment, wherein the coupling is designed not to perform any translational movement.

[0049] During (pneumatic) operation of the pressure cylinder, the clutch typically performs no movement (neither rotational nor translational movement). This reduces complexity and simplifies the movement mechanisms. For example, the clutch can be considered a component that is essentially stationary in the axial direction. The same can therefore apply to the motor. Thus, their positions are essentially fixed during operation of the pressure cylinder, which brings advantages for the arrangement. Pressure cylinders - General designs

[0050] A 10th embodiment of the pressure cylinder relates to one of the preceding 5th to 9th embodiments, wherein the pressure cylinder is a pressure cylinder according to one of the embodiments 1 to 4.

[0051] The person skilled in the art will understand that the features, technical properties, advantages and improvements of the pressure cylinder of embodiments 1 to 4 compared to the prior art also apply to the pressure cylinder of one of embodiments 5 to 9, insofar as this is technically reasonable.

[0052] An 11th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston rod is configured to have a stroke length of at most 5.0 mm, preferably at most 3.0 mm, further preferably at most 2.5 mm, even more preferably at most 2.0 mm, further preferably at most 1.5 mm, even more preferably at most 1.0 mm, further more preferably at most 0.7 mm, most preferably at most 0.5 mm; and / or wherein the piston rod is configured to have a stroke length of at least 0.005 mm, preferably at least 0.01 mm, further preferably at least 0.05 mm, most preferably at least 0.1 mm.

[0053] This stroke length (the distance traveled by the piston in the cylinder chamber during operation of the pressure cylinder) is significantly shorter than in the prior art. Consequently, a significant increase in the cycle rates (strokes / min or number of strokes per minute) of the pressure cylinder for material conveying devices can be achieved compared to conventional configurations. This allows the conveying speed of strip material to be increased, enabling more efficient processing of strip material. The stroke length can, for example, be defined by an axial length of the cylinder chamber and / or by an axial length of the piston in the cylinder chamber. Typically, a short axial length of the cylinder chamber can be selected, thus reducing the stroke length. This saves material.

[0054] It may be advantageous to provide a minimum stroke length and / or occasionally a longer stroke length. This can occur, for example, with wider roller feeds and / or when moving components of the roller feed (e.g., a rocker) are flexible and / or when flexible strip materials (e.g., plastics) are to be conveyed. Flexible can be understood as flexible and / or elastic. Consequently, a longer stroke length can compensate for system tolerances, which can be advantageous in some cases.

[0055] A 12th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the rotational movement of the first piston rod element changes a length of the piston rod, wherein preferably the rotational movement in a first direction increases the length, and the rotational movement in a second direction decreases the length.

[0056] The stroke length of the piston rod is short, yet strip materials of various thicknesses can be processed by increasing or decreasing the piston rod length. The pressure cylinder according to the invention can thus be used flexibly thanks to the adjustability of the piston rod length.

[0057] Therefore, there is no need to provide different pressure cylinders. A single pressure cylinder is sufficient, which can meet a wide range of requirements, as described herein.

[0058] For example, increasing the piston rod length results in a reduction in the distance between two rollers of a material conveyor. Reducing the piston rod length results in an increase in the distance between two rollers of a material conveyor.

[0059] Preferably, the ratio of the length of the piston rod set to a maximum length to the length of the piston rod set to a minimum length is approximately 110% to 150%, preferably 110% to 140%, more preferably 115% to 130%, most preferably 115% to 120% (or up to 125%). Thus, for example, an extension of the piston rod length of 10% to 50% can be achieved.

[0060] Preferably, the minimum length of the piston rod can be 86 mm to 106 mm, for example, 96 mm. Preferably, the maximum length of the piston rod can be 110 mm to 120 mm, for example, 115 mm. This can correspond to a ratio described herein of 115 mm / 96 mm = 119.8% (~120%). With these values ​​(ratios), the inventors enable the use of the pressure cylinder for a variety of roll feeds with different throughput ranges.

[0061] A 13th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the first piston rod element and the second piston rod element are engaged via a screw contact, in particular a thread.

[0062] The rotational movement of the first piston rod element causes a translational movement of the second piston rod element relative to the piston via a screw contact, e.g., a screw connection. Thus, the second piston rod element is driven via the thread of the screw contact. This represents a simplified and reliable movement mechanism.

[0063] A 14th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston is configured to cause a corresponding translational movement of the piston rod upon a translational movement of the piston.

[0064] When the piston performs a translational movement, the piston rod performs a corresponding translational movement of the same type and / or magnitude. The first and second piston rod elements also move.

[0065] A 15th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a sensor, preferably an eddy current sensor, configured to detect a current position of the piston, in particular in the cylinder chamber; wherein the sensor is preferably configured to detect a distance between the sensor and an underside of the piston.

[0066] The sensor is, for example, an analog sensor. Preferably, the sensor is a non-contact sensor. An eddy current sensor can reliably measure distance using a magnetic field. These measurements are advantageously very precise.

[0067] A current position can, in particular, include the distance between the sensor and the underside of the piston. Detection can also be understood as a measurement. Advantageously, the dimensions of components of the pressure cylinder are known, so that the sensor's measurement can be used to determine the extent to which the piston has moved. In this way, different thicknesses of a strip material can be advantageously detected. This can be useful, for example, for adjusting the piston rod length when changing strip material.

[0068] In addition, the measurement can be used for quality purposes, with evaluation via a control system. Furthermore, by detecting the current position, it can be determined whether intermediate release has occurred. This is particularly advantageous given the high cycle rates of the invention. Consequently, it can be monitored whether the pressure cylinder is still operating as intended.

[0069] The measurement can also be used to detect variations in the thickness of a strip material as it is advanced through a material conveyor. The measurement results could, for example, be used to indicate any (necessary) further adjustment of the piston rod length (e.g., readjustment).

[0070] A 16th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston rod is driven pneumatically, wherein the pressure cylinder is preferably configured such that translational movements of the piston and / or the first piston rod element occur exclusively pneumatically.

[0071] A pneumatic drive represents a reliable technology that allows the operation, especially the intermediate release, of the pressure cylinder to be carried out efficiently. As described herein, the second piston rod element can also perform a translational movement due to the rotational movement of the first piston rod element. This is possible in addition to the pneumatic drive and is advantageous for adjusting the piston rod length.

[0072] A 17th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: an upper air connection; and preferably a lower air connection; wherein the cylinder space is divided by the piston essentially into an upper cylinder space region, which communicates essentially exclusively with the upper air connection, and preferably into a lower cylinder space region, which communicates essentially exclusively with the lower air connection.

[0073] The air connection can be used to provide pressure in the cylinder chamber, which can cause the piston to move within the cylinder chamber. Two air connections are advantageously provided, each communicating with a cylinder chamber area. This communication is understood to mean enabling air exchange. Compressed air can thus be introduced specifically into the respective cylinder chamber area.

[0074] Two air connections offer the advantage of dual action compared to a single air connection. Therefore, no home position of the piston and / or piston rod is required. This can be achieved by adjusting the pressure.

[0075] The upper cylinder chamber area can be understood as such, when the pressure cylinder is operating properly, that the piston and piston rod increase the contact pressure when pressure is applied. The lower cylinder chamber area can be understood as such, when the pressure cylinder is operating properly, that the piston and piston rod decrease the contact pressure when pressure is applied. For example, the upper cylinder chamber area can be arranged vertically above the lower cylinder chamber area.

[0076] An 18th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a spacer disc arranged in the cylinder space; wherein the spacer disc optionally has a thickness of at most 4.0 mm, preferably at most 3.0 mm, further preferably at most 2.5 mm, most preferably at most 2.0 mm; and / or wherein the spacer disc optionally has a thickness of at least 0.5 mm, preferably at least 1.0 mm, further preferably at least 1.5 mm, most preferably at least 2.0 mm.

[0077] The spacer disc allows for individual and flexible adjustment of the stroke length. In one example, the piston stroke length can be reduced from 2.7 mm to 0.7 mm using a 2.0 mm thick spacer disc. In another example, the piston stroke length can be reduced from 2.5 mm to 0.5 mm using a 2.0 mm thick spacer disc. This advantageously allows for increased cycle rates. This offers significant advantages over the prior art, which depicts pressure cylinders with stroke lengths of 10 mm.

[0078] Preferably, the spacer disc is arranged on an upper wall of the cylinder chamber, for example on an upper wall of the upper cylinder chamber region.

[0079] The thickness can be understood as the axial dimension of the spacer. In one example, the spacer can have a shape that corresponds to a shape of the cylinder chamber. The spacer can typically be cylindrical. Typically, the radius of the spacer is significantly larger than the thickness of the spacer, for example by a factor of at least 3, 5, or 8. If arranged in the cylinder chamber, the spacer can also at least partially contact a lateral surface of the cylinder chamber. For assembly purposes, it can be advantageous if the spacer has a smaller radius than the cylinder chamber.

[0080] A 19th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: one, preferably two, plain bearings, which is / are configured to receive the piston rod; and an upper cylinder component and a lower cylinder component, which are firmly connected to one another and comprise the cylinder space, preferably enclosing the cylinder space in a substantially airtight manner; wherein the piston rod, the upper cylinder component, and preferably the lower cylinder component are arranged coaxially, wherein preferably the piston rod protrudes at least partially beyond the lower cylinder component.

[0081] The arrangement of the upper / lower cylinder components can be understood similarly to the arrangement of the upper / lower cylinder chamber area. For example, the upper cylinder component can be arranged vertically above the lower cylinder component.

[0082] The airtight seal can be understood as meaning that there is essentially no pressure loss during operation of the pressure cylinder. It goes without saying that a (planned) air exchange still occurs via the air connection(s). Air exchange between the lower and upper cylinder chamber areas is essentially prevented.

[0083] A coaxial arrangement means that the components essentially share a common axis. For example, this could be a longitudinal axis. This allows for a simplified design of the pressure cylinder.

[0084] A 20th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the first piston rod element has a cavity, wherein the second piston rod element is arranged at least partially within the cavity, wherein preferably the first piston rod element and the second piston rod element are arranged coaxially.

[0085] The cavity enables a space-saving arrangement, which saves material and resources. In particular, this prevents damage to the second piston rod element. If a threaded rod is included, this can also be arranged in the cavity of the first piston rod element.

[0086] As the piston rod length increases, the portion of the second piston rod element located in the cavity is reduced. As the piston rod length decreases, the portion of the second piston rod element located in the cavity is increased.

[0087] In one example, when the piston rod length is set to a maximum length, the part of the second piston rod element arranged in the cavity can comprise at least 5%, preferably at least 10%, further preferably at least 20%, more preferably at least 25%, even more preferably at least 30%, most preferably at least 35% of a length of the second piston rod element; and / or comprise at most 80%, preferably at most 70%, further preferably at most 60%, more preferably at most 50%, even more preferably at most 45%, most preferably at most 40% of a length of the second piston rod element.

[0088] In a further example, when the piston rod length is set to a minimum length, the part of the second piston rod element arranged in the cavity can comprise at least 20%, preferably at least 30%, further preferably at least 40%, more preferably at least 50%, even more preferably at least 60%, most preferably at least 65% of a length of the second piston rod element; and / or comprise at most 95%, preferably at most 90%, further preferably at most 85%, more preferably at most 80%, even more preferably at most 75%, most preferably at most 70% of a length of the second piston rod element.

[0089] The inventors have succeeded in determining an optimal value for the portion of the second piston rod element located within the cavity. This arises from the fact that the possible variation in the piston rod length should be large enough to accommodate a wide range of strip material thicknesses. At the same time, sufficient piston rod stability should be ensured. These conflicting requirements result in the values ​​described herein for the portion of the second piston rod element enclosed by the cavity.

[0090] It is conceivable that the cavity extends over the entire length of the first piston rod element.

[0091] Advantageously, the screw contact comprises an internal thread of the first piston rod element and an external thread of the second piston rod element.

[0092] A 21st embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the second piston rod element engages with the movable component of the material conveying device, but not the first piston rod element; wherein the movable component of the material conveying device is preferably a rocker configured to cause a translational movement of a roller of the material conveying device during movement.

[0093] Thus, only the engagement with the second piston rod element is achieved. Consequently, the second piston rod element can be mechanically designed for this engagement. The first piston rod element can therefore be mechanically designed differently. This increases flexibility.

[0094] In one example, the first piston rod element can also be considered an upper piston rod element and the second piston rod element a lower piston rod element. This serves to illustrate the arrangement (during normal operation of the pressure cylinder) and is in no way intended to be limiting. The two piston rod elements have an adjustable overlap area, preferably in their respective axial dimensions (as described herein).

[0095] During operation of the pressure cylinder, the pressure can be transferred from the pressure cylinder to a rocker. The rocker is preferably a movable rocker, which then transfers the pressure to the roller.

[0096] A 22nd embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston rod is configured such that the rotational movement of the first piston rod element causes substantially no translational movement of the first piston rod element relative to the cylinder space.

[0097] This arrangement ensures that the first piston rod element does not shift axially when it performs a rotational movement. This is useful because otherwise the rotational movement described herein might be difficult. Furthermore, the rotational movement of the first piston rod element only serves to translate, or shift, the second piston rod element.

[0098] A 23rd embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston and the second piston rod element are two separate components, wherein preferably the first piston rod element and the second piston rod element are two separate components.

[0099] Separate components offer the advantage that if one of the components wears out, only the worn component needs to be replaced. This reduces costs. Furthermore, the separate design allows for simplified adjustment of the piston rod length.

[0100] A 24th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the translational movements run parallel to each other, wherein the translational movements preferably run substantially at right angles to a material which is to be conveyed by the material conveying device.

[0101] The translational movements may include the translational displacement / movement and / or axial displacement / movement described herein. Preferably, the translational movements are vertical, with proper operation of the pressure cylinder.

[0102] A 25th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the pressure cylinder is configured such that the piston performs a translational movement over the entire axial length of the cylinder chamber.

[0103] This offers the advantage that the pressure cylinder can, for example, be operated over the entire stroke length. Preferably, the piston thus performs no movement during the stroke, with a reversal of movement taking place in a central axial region of the cylinder chamber. The axial length can be understood as parallel to the translational direction of movement (as described herein). It is therefore not necessary to provide a separate component that would impair or even reduce the translational movement of the piston during operation. Advantageously, the pressure cylinder can always be operated in the same way, regardless of the thickness of the strip material to be conveyed.

[0104] A 26th embodiment of the invention relates to a material conveying device, in particular a roller feed, comprising a pressure cylinder according to one of the preceding embodiments.

[0105] The person skilled in the art will understand that the technical characteristics shown herein for the pressure cylinder, the advantages of the pressure cylinder and the improvements over the prior art apply equally to the material conveying device.

[0106] The material conveying device can therefore be operated at a significantly increased cycle rate. Due to the flexible adjustability of the pressure cylinder according to the invention, different strip materials can be processed in one material conveying device. This contributes to an efficient and cost-effective material conveying device.

[0107] According to a 27th embodiment, the material conveying device of the preceding embodiment further comprises a rocker and a roller; wherein the piston rod of the pressure cylinder is configured to increase pressure on the rocker in order to effect a translational movement of the roller directed towards a material to be conveyed by the material conveying device; wherein the piston rod of the pressure cylinder is further configured to reduce pressure on the rocker in order to effect a translational movement of the roller directed away from the material to be conveyed by the material conveying device.

[0108] The material conveying device according to the invention combines all the above-described advantages of the pressure cylinder with a roller and, if appropriate, with a rocker.

[0109] During operation of the pressure cylinder, intermediate release can occur (in this embodiment, this is to be understood as an increase / decrease in pressure). The intermediate release serves, for example, to raise a roller after each feed cycle of the strip material in order to release the strip material for a subsequent cutting tool. The rocker can be configured such that when the pressure on the rocker is reduced (for example, when the pressure on a surface of the piston is reversed, thus when the piston moves upwards), the rocker is moved upwards. Extending the length of the piston rod does not necessarily lead to an increase in the pressure described herein. Preferably, extending the length of the piston rod does not lead to an increase in the pressure described herein. The pressure described herein is preferably applied pneumatically by means of the piston.

[0110] The direction of movement toward the material can be understood, in one example, as vertically downward. The direction of movement away from the material can be understood, in one example, as vertically upward.

[0111] A 28th embodiment relates to the material conveying device according to one of the preceding 26th or 27th embodiments, wherein the rotational movement of the first piston rod element changes a distance, preferably an axial distance, of the piston rod and / or the roller to a material to be conveyed by the material conveying device, wherein preferably the rotational movement in a first direction reduces the distance, and the rotational movement in a second direction increases the distance.

[0112] The piston rod length can be changed, for example, to change a home position of the rocker and / or the roller. As described herein, the rotational movement in the first direction causes a length of the piston rod to be increased. Consequently, a distance of the piston rod, the rocker, and / or the roller from a strip material can be reduced. As described herein, the rotational movement in the second direction causes a length of the piston rod to be reduced. Consequently, a distance of the piston rod, the rocker, and / or the roller from a strip material can be increased.

[0113] A 29th embodiment relates to the material conveying device according to one of the preceding 26th to 28th embodiments, wherein the pressure increase and / or the pressure reduction is pneumatic; wherein the rotational movement is non-pneumatic.

[0114] A 30th embodiment of the invention relates to a method for adjusting a piston rod length of a pneumatic pressure cylinder in a material conveying device, in particular a pressure cylinder according to one of embodiments 1 to 25, comprising: optionally depressurizing the pressure cylinder; introducing material, in particular strip material, into the material conveying device; rotating a first piston rod element of a piston rod of the pressure cylinder in a first direction to effect a translational movement of a second piston rod element of the piston rod of the pressure cylinder; terminating the rotation in the first direction when contact or a predefined distance between a movable component of the material conveying device and the material is reached;optionally rotating, preferably when contact has been achieved, the first piston rod member in a second direction to cause an opposite translational movement of the second piston rod member;

[0115] Depressurization can be used to allow the piston to move in one direction, for example, upwards, preferably all the way up. This places the piston at the upper end of the cylinder chamber. This facilitates adjusting the length of the piston rod, for example, for thick strip material.

[0116] Rotation in the first direction can also be stopped once a predefined distance has been reached. This distance can, for example, be an axial, preferably vertical, distance between the rocker and / or roller (preferably roller) and the strip material (material).

[0117] In particular, if a motor is included, the process can be automated. The rotation in the first direction is advantageously carried out with the aid of the motor. The rotation in the first direction can be automated until contact is made between the roller and the strip material. This contact can be detected, for example, by an increased current consumption of the motor. It is also possible to detect the contact using a sensor, preferably arranged in the cylinder chamber. This sensor can be an eddy current sensor.

[0118] Rotation in the second direction can then take place. This rotation in the second direction should preferably only occur to the extent that the strip material is released. Advantageously, the distance between the roller and the strip material should be so small that sufficient pressure can be built up between the roller and the strip material during a translational movement of the piston over the stroke length (during operation of the pressure cylinder). This pressure should be sufficient to provide sufficient traction for an advancing movement of the strip material. The pressure can vary depending on the strip material and can be adjusted using a pressure regulator. A pressure in the range of 1.5 bar to 8 bar, preferably in the range of 2 bar to 6 bar, is conceivable.

[0119] Preferably, the piston is pressurized so that the material conveying device is ready for operation to convey strip material.

[0120] A 31st embodiment relates to the method according to the preceding embodiment, further comprising: rotating the first piston rod member in the second direction prior to introducing material.

[0121] This offers the advantage that the piston rod can be adjusted to a reduced length, preferably the smallest possible length. Consequently, this provides the possibility of conveying thicker strip material. 4. Short description of the characters

[0122] Preferred embodiments are described below by way of example only. Reference is made to the accompanying figures: Fig. 1 shows a pressure cylinder in a material conveying device according to an embodiment of the present invention; Fig. 2 shows a pressure cylinder according to a first aspect of the present invention in a perspective view; Fig. 2a shows the pressure cylinder according to Fig. 2in a side cross-sectional view; Fig. 2b shows the pressure cylinder according to Fig. 2a , with the piston rod extended; Fig. 2c shows the pressure cylinder similar to Fig. 2a , where the piston is moved translationally downwards (the length of the piston rod is Fig. 2a reduced to a minimum); Fig. 3 shows a pressure cylinder according to a second aspect of the present invention in a perspective view; Fig. 3a shows the pressure cylinder according to Fig. 3 in a further perspective view; Fig. 3b shows the pressure cylinder according to Fig. 3 in a side cross-sectional view; Fig. 3c shows the pressure cylinder according to Fig. 3b , with the piston rod extended; Fig. 3d shows the pressure cylinder according to Fig. 3b, wherein the piston is moved translationally downwards; Fig. 4 shows a pressure cylinder according to an embodiment of the present invention; Fig. 5 shows a pressure cylinder according to a further embodiment of the present invention; and Fig. 6 shows a schematic flow diagram of a method for adjusting a piston rod length according to an embodiment of the present invention. 5. Detailed description of the characters Definitions

[0123] One rotational movement, Rotation and turning can be considered synonymous here.

[0124] One stroke length can also be understood as a path length, in particular as a total path length, which the piston travels in the cylinder chamber during operation of the pressure cylinder. This can also be understood as Piston strokeFor example, this can be an axial length between the piston and the wall of the cylinder chamber. In some cases, as preferred herein, the stroke length can correspond to the entire axial length of the cylinder chamber (minus a portion occupied by the piston).

[0125] The Pressure cylinder The present invention can also be understood as an intermediate release cylinder. The pressure cylinder should not be understood in any way as restrictive in the sense that the pressure cylinder necessarily causes pressure. However, the pressure cylinder is intended to be suitable for a material conveying device and therefore differs, for example, from cylinders commonly used in the operation of motor vehicles and / or piston engines. Character description

[0126] In the following, only a few possible embodiments of the invention are described in detail. However, the present invention is not limited to these, and a variety of other embodiments are applicable without departing from the scope of the invention. The presented embodiments can be modified and combined with each other in many ways whenever they are compatible, and certain features can be omitted where they appear unnecessary. In particular, the disclosed embodiments can be modified by combining certain features of one embodiment with one or more features of another embodiment.

[0127] Throughout these figures and the description, the same reference numerals refer to the same elements. It should be understood that the reference numerals (100-199) of the figures of the first aspect also apply to the figures of the second aspect (with reference numerals 200-299) and are not shown separately for convenience only. The figures may not be to scale, and the relative size, proportions, and representation of elements in the figures may be exaggerated for clarity, illustration, and convenience.

[0128] Fig. 1 shows a pressure cylinder 100, 200 (from now on the reference number 200 will not be listed separately, but should also be used) in a material conveying device (in particular in a roller feed) 1 according to an embodiment of the present invention.

[0129] The material conveying device 1 comprises a rocker 2 and a roller 5. In particular, the material conveying device 1 further comprises a lower roller 6. The rollers 5, 6 of the material conveying device 1 can convey strip material 10 (in Fig. 1 not shown and merely indicated by a reference symbol) in the conveying direction F.

[0130] The pressure cylinder 100 comprises a piston rod 110 configured to engage with a movable component 2 of the material conveying device 1. Furthermore, the pressure cylinder 100 comprises a cylinder chamber 120 configured to at least partially guide the piston rod 110. This means, for example, that the piston rod 110 extends through the cylinder chamber 120. Furthermore, a piston 130 is included, which is movably arranged in the cylinder chamber 120 and which is connected to the piston rod 110 (for example, at least partially by a positive connection).

[0131] The piston rod 110 comprises a first piston rod element 111 and a second piston rod element 112, which are configured such that a rotational movement of the first piston rod element 111 causes a translational movement of the second piston rod element 112 relative to the piston 130. In this way, the length of the piston rod 110 can be changed.

[0132] The piston rod 110 of the pressure cylinder 100 is configured to increase pressure on the rocker 2 in order to effect a translational movement of the roller 5 toward a strip material 10 that is to be conveyed by the material conveying device 1. The rocker 2 can rotate about the pivot point 3. The piston rod 110 of the pressure cylinder 100 is further configured to reduce pressure on the rocker 2 in order to effect a translational movement of the roller 5 away from the strip material 10 that is to be conveyed by the material conveying device 1. The increase or decrease in pressure occurs by means of a pneumatic operation of the drive cylinder 100 and can take place during intermediate release, for example at least 1500 strokes / min or at least 2000 strokes / min or at least 2500 strokes / min.

[0133] In this exemplary arrangement, the direction toward the material 10 can be understood as vertically downward. The direction away from the material 10 can be understood as vertically upward.

[0134] Strip materials with a thickness of 0.05 mm to 15 mm, preferably from 0.05 mm to 10 mm, more preferably from 0.05 mm to 8 mm, most preferably from 0.1 mm to 5 mm can be processed.

[0135] Fig. 2 shows a pressure cylinder 100 according to a first aspect of the present invention in a perspective view.

[0136] The pressure cylinder 100 comprises an upper cylinder component 140 and a lower cylinder component 145, which are firmly connected to one another, for example, via a screw connection. The two cylinder components 140, 145 enclose the cylinder chamber (not shown) in a substantially airtight manner.

[0137] The pressure cylinder 100 also comprises an upper air connection 141 and a lower air connection 146. Through these air connections 141, 146, compressed air can be introduced into the cylinder chamber (or into an upper and a lower cylinder chamber area) (pressure build-up) or released (pressure reduction).

[0138] The pressure cylinder 100 comprises a releasable locking device 170, which is arranged at one end of the piston rod, essentially in the longitudinal direction of the piston rod (only the second piston rod element 112 of the piston rod is identified). The locking device 170 is designed to lock an adjustable length of the piston rod. The locking device 170 comprises a knurled nut 171, which engages the threaded rod (not shown). The pressure cylinder 100 comprises a handwheel 180, which, upon rotation, exerts a correspondingly parallel rotational movement on the first piston rod element (not shown).

[0139] Fig. 2a shows the pressure cylinder 100 according to Fig. 2 in a lateral cross-sectional view.

[0140] Shown are the first piston rod element 111 and the second piston rod element 112. Both piston rod elements together form the piston rod 110 (not separately marked).

[0141] The cylinder chamber 120 is essentially divided by the piston 130 into an upper cylinder chamber region 142, which communicates essentially exclusively with the upper air connection 141, and a lower cylinder chamber region 147, which communicates essentially exclusively with the lower air connection 146. In this figure, the upper cylinder chamber region 142 is not shown, and the space of the cylinder chamber 120 not filled by the piston 130 is essentially defined by the lower cylinder chamber region 147, since the piston 130 is shown in an upper end position.

[0142] The pressure cylinder 100 includes two plain bearings 150 configured to support the piston rod 110. In particular, the first piston rod element 111 is supported by the two plain bearings 150.

[0143] The pressure cylinder 100 comprises a threaded rod 160, which is arranged at least partially within the piston rod 110, in particular within the first piston rod element 111. The threaded rod 160 is substantially fixedly connected to the second piston rod element 112.

[0144] A washer 172 is arranged between the locking device 170 and the piston rod 110 (represented by 111 and 112). The threaded rod 160 extends through the washer 172. Thus, the threaded rod 160 is arranged within the first piston rod element 111 and the knurled nut 171. The knurled nut 171 can be screwed over the upper thread 161 of the threaded rod 160 and then locks the rotational position of the handwheel 180. For example, during operation of the pressure cylinder 100, a set length of the piston rod 110 can advantageously not change.

[0145] The fixed connection between the threaded rod 160 and the second piston rod element 112 can be made via a screw connection, in particular via a lower thread 162 of the threaded rod 160. Preferably, the connection can be made with the aid of an adhesive, for example, Loctite.

[0146] The piston rod 110 (represented by 111 and 112), the upper cylinder component 140, and the lower cylinder component 145 are arranged coaxially. Furthermore, the piston rod 110, in particular the second piston rod element 112, protrudes at least partially beyond the lower cylinder component 145.

[0147] Fig. 2b shows the pressure cylinder 100 according to Fig. 2a , with the piston rod 110 extended. For clarity, not all reference symbols from the previous figure are shown. The corresponding reference symbols from the preceding figures apply to components not explicitly identified.

[0148] This figure shows an arrangement in which the length L0 of the piston rod 110 is extended. A comparison with the previous figure shows that the second piston rod element 112 is translationally displaced (axially downward in the figure). A rotary movement of the first piston rod element 111 causes a change in the length of the piston rod 110. The rotary movement in a first direction increases the length L0, and the rotary movement in a second direction decreases the length L0. The first and second directions are opposite. The rotary movement occurs by rotation about the longitudinal axis of the first piston rod element 111. The first piston rod element 111 and the second piston rod element 112 are engaged via a thread 115. The rotary movement is transmitted from the first piston rod element 111 to the second piston rod element 112 via this thread 115.

[0149] A handwheel 180 is shown, which, when rotated, exerts a correspondingly unidirectional rotational movement on the first piston rod element 111. This facilitates the adjustment of the length of the piston rod 110, as it has a larger radius than the first piston rod element 111 and thus requires less force while maintaining the same torque. The connection between the handwheel 180 and the first piston rod element 111 can be provided via a square connection.

[0150] The first piston rod element 111 has a cavity 113, with the second piston rod element 112 being arranged at least partially within the cavity 113. The first piston rod element 111 and the second piston rod element 112 are arranged coaxially.

[0151] When the length Lo of the piston rod 110 is set to a minimum length (similar to Fig. 2c), the part located in the cavity 113 is L2 (the marking is in Fig. 2c visible) of the second piston rod element 112 at least 20% and / or a maximum of 95%, preferably at least 30% and / or a maximum of 90%, for example 63% of the length L1 (the marking is in Fig. 2c visible) of the second piston rod element 112.

[0152] When the length Lo of the piston rod 110 is set to a maximum length Lo (similar to Fig. 2b ), the part located in the cavity 113 is L2 (the marking is in Fig. 2c visible) of the second piston rod element 112 at least 5% and / or a maximum of 80%, preferably at least 10% and / or a maximum of 70%, for example 38% of the length L1 (the marking is in Fig. 2c visible) of the second piston rod element 112.

[0153] A comparison of the length Lo of the piston rod 110, which is set to a maximum length ( Fig. 2b) to the length Lo of the piston rod 110, which is set to a minimum length ( Fig.2c ), shows values ​​ranging from 110% to 150%. In this example, a value of 120% results, so the piston rod 110 can advantageously be extended by 20% of its smallest length. Expressed in absolute terms, the maximum length Lo can be 115 mm and the minimum length L0 can be 95 mm.

[0154] Fig. 2c shows the pressure cylinder 100 according to Fig. 2a , with the piston 130 being moved downwards. In addition, the length Lo of the piston rod 110 is reduced to a minimum (in Fig. 2a the length Lo of the piston rod 110 has not yet been completely reduced to a minimum).

[0155] During (pneumatic) operation of the pressure cylinder 100, the air connections serve to provide a pressure in the cylinder chamber 120, which causes the piston 130 to move within the cylinder chamber 120. The position of the piston 130 is shown at a lower end of the cylinder chamber 120. Therefore, the lower cylinder chamber area 147 is not shown in this figure, and the cylinder chamber 120 not filled by the piston 130 is essentially defined by the upper cylinder chamber area 142.

[0156] During (pneumatic) operation of the pressure cylinder 100, the handwheel 180 is moved translationally together with the piston rod 110 and the piston 130 (e.g., during intermediate release). For this purpose, an air gap can be provided between the handwheel 180 and a wall of an upper cylinder component 140, so that friction losses are largely avoided. A comparison of Fig. 2a and Fig. 2cindicates the arrangement of the handwheel 180 in the two different positions of the piston 130 of the pressure cylinder 100.

[0157] The stroke length L3 is defined by an axial length of the cylinder chamber 120. In particular, the stroke length L3, as shown, can be described by the (axial) distance between the piston 130 and the upper end of the cylinder chamber 120. Thus, the stroke length L3 according to this figure is defined by the axial length of the upper cylinder chamber region 142.

[0158] Advantageously, the axial length of the cylinder chamber 120 (or, as seen here, the upper cylinder chamber area 142) is short, so that the stroke length L3 is kept short. Consequently, an increased cycle rate can be achieved.

[0159] The piston 130 advantageously performs a translational movement over the entire axial length L3 of the cylinder chamber 120 (excluding the axial length of the cylinder chamber 120 occupied by the piston 130). The entire axial length is represented by the stroke length L3.

[0160] Fig. 3shows a pressure cylinder 200, 100 (hereinafter referred to only as 200) according to a second aspect of the present invention in a perspective view. Those skilled in the art will understand that the same reference numerals designate the same components of the first aspect. For example, 112 stands for the second piston rod element 112. Consequently, the same components of the first aspect can also be used for the second aspect. Advantageously, in the second aspect, a threaded rod, a handwheel, and / or a separate locking mechanism are not absolutely necessary. In the second aspect, the first piston rod element 111 can advantageously be configured to be rotatable relative to the piston 130 (or the piston 130 can be rotatable relative to the first piston rod element 111).

[0161] The second piston rod element 112 comprises a fixing component, which can be a transverse pin, whereby rotation of the second piston rod element 112 upon rotation of the first piston rod element 111 can be substantially prevented. The fixing component protrudes laterally at least partially beyond a side surface of the piston rod. The fixing component can be engaged with a movable component 2 of the material conveying device 1. The fixing component can be provided in all second piston rod elements 112 described herein. Alternatively or additionally, an installation position of the second piston rod element 112 in a movable component 2 of the material conveying device 1 can substantially prevent rotation of the second piston rod element 112 upon rotation of the first piston rod element 111.

[0162] The pressure cylinder further comprises a motor 280 which is configured to cause the rotational movement of the first piston rod element 111.

[0163] Fig. 3a shows the pressure cylinder 200 according to Fig. 3 in another perspective view.

[0164] In this figure, the pressure cylinder 200 is shown without the motor 280 for illustrative purposes. It can be seen that the first piston rod element 111 has a square shape, which enables a positive square connection to a coupling 281 of the motor 280.

[0165] Fig. 3b shows the pressure cylinder 200 according to Fig. 3 in a side cross-sectional view. This figure shows the components, the designations of which are familiar to the expert, among other things, Fig. 2-2c and are not listed again for reasons of clarity.

[0166] The motor 280 further comprises a coupling 281, which is substantially fixedly connected to a motor shaft 282 of the motor 280, wherein the coupling 281 engages the first piston rod element 111. The piston rod 110, in particular the first piston rod element 111, is configured to be axially movable relative to the coupling 281. The piston rod 110, in particular the first piston rod element 111, is not configured to be rotatable relative to the coupling 281. Thus, the two components are substantially rotationally fixedly connected (via the square connection described herein). The coupling 281 can thus prevent an (unintentional) rotational movement of the first piston rod element 111 and / or effect an (intentional) rotational movement of the first piston rod element 111. Consequently, an (unintentional) change in a set length Lo of the piston rod 110 can be substantially prevented.

[0167] Fig. 3c shows the pressure cylinder 200 according to Fig. 3b, the piston rod 110 being extended. To understand the reference symbols in this figure, the corresponding description points of the Fig. 2b . In particular, the person skilled in the art understands the change in the length Lo of the piston rod 110 between Fig. 3b and Fig. 3c by changing the length Lo of the piston rod 110 between Fig. 2b and Fig. 2c (and between Fig. 2b and Fig. 2a ).

[0168] Advantageously, with reference to Fig. 3b and Fig. 3c However, the rotational movement of the first piston rod element 111 is caused by the motor 280.

[0169] When the length Lo of the piston rod 110 is set to a minimum length (similar to Fig. 3b or Fig. 3d), the part L2 of the second piston rod element 112 arranged in the cavity 113 is at least 20% and / or a maximum of 95%, preferably at least 30% and / or a maximum of 90%, for example 66% of the length L1 of the second piston rod element 112.

[0170] When the length Lo of the piston rod 110 is set to a maximum length, the part L2 of the second piston rod element 112 arranged in the cavity 113 is at least 5% and / or a maximum of 80%, preferably at least 10% and / or a maximum of 70%, for example 36% of the length L1 of the second piston rod element 112.

[0171] A comparison of the length Lo of the piston rod 110, which is set to a maximum length ( Fig. 3c ) to the length Lo of the piston rod 110, which is set to a minimum length ( Fig. 3b and Fig. 3d), shows values ​​in the range from 110% to 150%. In this example, the value is 120%, so the piston rod 110 can advantageously be extended by 20% of its smallest length.

[0172] Fig. 3d shows the pressure cylinder 200 according to Fig. 3b , with the piston moving downwards. The length Lo of the piston rod 110 is as in Fig. 3b reduced to a minimum. The ratio of length L2 to L1 is thus at its largest.

[0173] Similar to Fig. 2c described, is in Fig. 3d The piston 130 is shown in a lower position. This is achieved due to the pneumatic operation of the pressure cylinder 200, whereby the piston 130 is moved downwards in a translational manner (by applying pressure to a lower air connection, the piston 130 can be moved upwards accordingly). The corresponding descriptions apply to Fig. 2c also for Fig. 3d .

[0174] Fig. 4 shows the pressure cylinder 100, 200 according to an embodiment of the present invention. This embodiment applies equally to both aspects.

[0175] The pressure cylinder 100, 200 includes a spacer disk 121 arranged in the cylinder chamber 120. The spacer disk 121 has a maximum thickness of 4.0 mm and / or at least 0.5 mm. In this example, it has a thickness of 2.0 mm. The stroke length L3 in this example is 0.7 mm (2.7 mm without the spacer disk 121). Thus, the stroke length L3 can be advantageously reduced. This enables higher cycle rates. For example, the stroke length L3 of 0.7 mm can also mean an intermediate air opening of 0.7 mm, which the pressure cylinder 100, 200 provides.

[0176] The spacer disc 121 is arranged on an upper wall of the upper cylinder chamber area 141 (not separately marked), which wall coincides with a lower wall of the upper cylinder component 140.

[0177] The (axial) end positions of the piston 130 in the cylinder chamber 120 are provided via a lower wall of the upper cylinder component 140 (or a spacer disc 121, as described herein) and an upper wall of the lower cylinder component 145.

[0178] For example, the pressure cylinder 100, 200 can enable at least 1500 strokes / min, or at least 2000 strokes / min. This advantageously provides high cycle rates. In one example, it could also be relevant how much time is available to execute the stroke. This can be influenced by an intermediate release angle and / or a required (air) pressure: The intermediate release angle can influence the time available to execute an intermediate release stroke (hence moving the piston upwards and then downwards). For example, an intermediate release angle of 60° (assuming 500 strokes / min, which means 0.12 seconds / stroke) means that only 360° / 60° = 1 / 6 of the time is available to execute an intermediate release (0.12 seconds / stroke / 6 = 0.02 seconds / stroke). Consequently, in one example, higher cycle rates (higher stroke / min) can be achieved at higher intermediate air angles (since more time is available).The example is for clarification purposes only and should not be construed as limiting.

[0179] The influence of pressure can be understood as follows: The lower the air pressure required, the faster the cylinder chamber can be filled. At higher required air pressures, more air volume must be introduced into the cylinder chamber, since, under simplified assumptions, the air can be compressed according to the ideal gas law.

[0180] Fig. 5 shows the pressure cylinder 100, 200 according to another embodiment of the present invention.

[0181] The pressure cylinder 100, 200 comprises a sensor 155, preferably an eddy current sensor 155, which is configured to detect a current position of the piston 130 in the cylinder chamber 120. The sensor 155 is configured to detect a distance between the sensor 155 and an underside of the piston 130.

[0182] The principle of a measurement using an eddy current sensor 155 can be understood as follows: When an electrically conductive body is moved in a magnetic field, eddy currents occur in this field because a voltage is induced in the electrically conductive body. Thus, dimensions, distances, and / or positions, particularly of electrically conductive components, can be determined.

[0183] Fig. 6shows a schematic flow diagram of a method 1000 for adjusting a length Lo of a piston rod 110 of a pneumatic pressure cylinder 100, 200 in a material conveying device 1 according to an embodiment of the present invention.The method 1000 comprises: optionally depressurizing 1100 the pressure cylinder 100, 200; optionally rotating 1200 the first piston rod element 111 in the second direction; introducing 1300 material 10, in particular strip material, into the material conveying device 1; rotating 1400 a first piston rod element 111 of a piston rod 110 of the pressure cylinder 100, 200 in a first direction to effect a translational movement of a second piston rod element 112 of the piston rod 110 of the pressure cylinder 100, 200; terminating the rotation 1500 when contact or a predefined distance between a movable component 2, 5 of the material conveying device 1 and the material 10 is reached; optionally rotating 1600, preferably when contact has been achieved, the first piston rod member 111 in a second direction to cause an opposite translational movement of the second piston rod member 112.

[0184] In the above embodiments, it may be particularly advantageous that, for thick strip material 10, the piston rod length 110 is typically reduced. For thin strip material 10, the piston rod length 110 is typically increased.

[0185] The pressure (contact pressure) provided during operation of the contact cylinder (for intermediate release) may sometimes depend on the strip material, in particular a surface of the strip material, an acceleration of the material conveying device onto the strip material and a multitude of other parameters.

[0186] The scope of protection is determined by the patent claims and is not limited by the embodiments and / or figures. 6. List of reference symbols

[0187] 1Material conveying device, in particular roller feed 2Rocker 3Pivot point of the rocker 5, 6Roller 10Strip material FConveying direction of the strip material LoLength of the piston rod L1Length of the second piston rod element L2Part of the second piston rod element that is arranged in the cavity of the first piston rod element L3Stroke length 100,200Pressure cylinder 110Piston rod 111First piston rod element 112Second piston rod element 113Cavity of the first piston rod element 115Thread 120Cylinder chamber 121Spacer disc 130Piston 140Upper cylinder component 141Upper air connection 142Upper cylinder chamber area 145Lower cylinder component 146Lower air connection 147Lower cylinder chamber area 150Sliding bearing 155Sensor 160Threaded rod 161Upper thread of the threaded rod 162Lower thread of the threaded rod 170Locking device 171Knurled nut 180Handwheel 280Motor 281Coupling 282Motor shaft 1000Process 1100Process step: optional depressurization 1200Process step: optional turning in a second direction 1300Process step: Inserting material 1400Process step: Turning in a first direction 1500Process step: Completing the turning 1600Process step: Optionally turning in a second direction,

Claims

1. A pressure cylinder (100, 200) for a material conveying device (1), in particular for a roller feed, comprising: a piston rod (110) configured to engage with a movable component (2, 5) of the material conveying device (1); a cylinder chamber (120) configured to at least partially guide the piston rod (110); and a piston (130) movably arranged in the cylinder chamber (120) and connected to the piston rod (110); wherein the piston rod (110) comprises a first piston rod element (111) and a second piston rod element (112) configured such that a rotational movement of the first piston rod element (111) causes a translational movement of the second piston rod element (112) relative to the piston (130); wherein the first piston rod element (111) is configured to be rotatable relative to the piston (130).

2. The pressure cylinder (100, 200) according to the preceding claim, wherein the piston (130) and the first piston rod element (111) are two separate components.

3. The pressure cylinder (100, 200) according to any one of the preceding claims, further comprising: a threaded rod (160) which is arranged at least partially within the piston rod (110) and which is substantially fixedly connected to the second piston rod element (112).

4. The pressure cylinder (100, 200) according to any one of the preceding claims, further comprising: a releasable locking device (170) arranged at one end of the piston rod (110) substantially in the longitudinal direction of the piston rod (110), and configured to lock an adjustable length of the piston rod (110); wherein the locking device (170) preferably comprises a screw connection (171) optionally engaged with the threaded rod (160).

5. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the piston rod (110) is configured to have a stroke length (L3) of a maximum of 5.0 mm, preferably a maximum of 3.0 mm, more preferably a maximum of 2.5 mm, even more preferably a maximum of 2.0 mm, more preferably a maximum of 1.5 mm, even more preferably a maximum of 1.0 mm, even more preferably a maximum of 0.7 mm, most preferably a maximum of 0.5 mm; and / or wherein the piston rod (110) is configured to have a stroke length (L3) of at least 0.005 mm, preferably at least 0.01 mm, more preferably at least 0.05 mm, most preferably at least 0.1 mm.

6. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the rotational movement of the first piston rod element (111) changes a length (Lo) of the piston rod (110), wherein preferably the rotational movement in a first direction increases the length (Lo), and the rotational movement in a second direction decreases the length (Lo).

7. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the first piston rod element (111) and the second piston rod element (112) are engaged via a screw contact (115), in particular a thread.

8. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the piston (130) is configured to cause a corresponding translational movement of the piston rod (110) upon a translational movement of the piston (130).

9. The pressure cylinder (100, 200) according to one of the preceding claims, further comprising: a sensor (155), preferably an eddy current sensor, which is configured to detect a current position of the piston (130), in particular in the cylinder chamber (120); wherein the sensor (155) is preferably configured to detect a distance between the sensor (155) and an underside of the piston (130).

10. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the piston rod (110) is driven pneumatically, wherein the pressure cylinder (100, 200) is preferably configured such that translational movements of the piston (130) and / or the first piston rod element (111) take place exclusively pneumatically.

11. The pressure cylinder (100, 200) according to one of the preceding claims, further comprising: a spacer disk (121) arranged in the cylinder space (120); wherein the spacer disk (121) optionally has a thickness of at most 4.0 mm, preferably at most 3.0 mm, further preferably at most 2.5 mm, most preferably at most 2.0 mm; and / or wherein the spacer disk (121) optionally has a thickness of at least 0.5 mm, preferably at least 1.0 mm, further preferably at least 1.5 mm, most preferably at least 2.0 mm.

12. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the first piston rod element (111) has a cavity (113), wherein the second piston rod element (112) is arranged at least partially within the cavity (113), wherein preferably the first piston rod element (111) and the second piston rod element (112) are arranged coaxially.

13. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the pressure cylinder (100, 200) is configured such that the piston (130) performs a translational movement over the entire axial length of the cylinder chamber (120).

14. Material conveying device (1), in particular roller feed, comprising a pressure cylinder (100, 200) according to one of the preceding claims.

15. A method (1000) for adjusting a piston rod length of a pneumatic pressure cylinder (100, 200) in a material conveying device (1), in particular a pressure cylinder (100, 200) according to one of claims 1 to 14, comprising: optionally depressurizing (1100) the pressure cylinder (100, 200); introducing (1300) material (10), in particular strip material, into the material conveying device (1); rotating (1400) a first piston rod element (111) of a piston rod (110) of the pressure cylinder (100, 200) in a first direction to effect a translational movement of a second piston rod element (112) of the piston rod (110) of the pressure cylinder (100, 200); Stopping the rotation (1500) when contact or a predefined distance between a movable component (2, 5) of the material conveying device (1) and the material (10) is reached;optionally rotating (1600), preferably when contact has been achieved, the first piston rod element (111) in a second direction to cause an opposite translational movement of the second piston rod element (112);

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