Pressure cylinder for a material conveying device

Description

1. Technical field

[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, and a method for adjusting the length of a piston rod of a pressure cylinder. 2. State of the art

[0003] Material handling devices, especially roller feeders, are used, for example, for conveying and advancing, particularly for the timed advancing of workpieces such as strip or ribbon material. Roller feeders are used, for instance, in stamping applications. Here, the workpiece is advanced at a timed interval, with the feed rate synchronized with a stamping tool.

[0004] Roller feeders are also known from other fields of application. For example, a roller feeder can have a profiled roller and, as the workpiece is advanced, imprint or stamp the corresponding profile into the workpiece.

[0005] The principle of roller feeding is basically based on at least two rollers, of which at least one 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. To feed / convey the workpiece, it is inserted into a gap formed between the rollers. The workpiece is then advanced / conveyed by the synchronous rotation of the rollers. The rotational speed of the rollers determines the conveying / feed speed.

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

[0008] Firstly, pressure cylinders are intended to apply a contact pressure to a roller, for example, the upper roller. This contact pressure enables the conveyor belt material fed into the material handling device to be transported with minimal slippage. Typically, the pressure from the pressure cylinder is applied to a movable rocker arm, which then transmits the pressure to the roller. The rocker arm can rotate around a pivot point.

[0009] Furthermore, the pressure cylinders should be able to lift the roller to allow the insertion of new strip material. This lifting is achieved, for example, by moving a piston upwards within the cylinder, which in turn moves the rocker arm and the upper roller upwards.

[0010] Furthermore, the pressure cylinders should enable intermediate lifting, which can also be described as "releasing" the material. Intermediate lifting involves raising the roller after each feed cycle of the strip material to release it for a progressive cutting tool. This allows the progressive cutting tool, for example, a punching tool, to be better centered and aligned with pre-punched holes. For example, strip materials can be aligned via pilot pins and pre-punched pilot holes through this intermediate lifting.

[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 is a significant parameter in material handling 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 known as the cycle rate and is usually expressed as strokes / min. Increased cycle rates can significantly improve the efficiency of material handling devices. Therefore, the cycle rates of the pressure cylinder should be increased. Furthermore, it should be possible to process a wide variety of strip material thicknesses. In addition, the design should be simple and cost-effective.

[0012] Conventional configurations do not meet these requirements. Conventional configurations include, for example, standard pneumatic cylinders or servo motors. Standard pneumatic cylinders typically have a long stroke. This long stroke limits the cycle rates (for example, only 300 strokes / min can be achieved). The long stroke and the associated larger friction surfaces also lead to increased material wear. This results in more frequent malfunctions, making the configuration costly overall. Furthermore, it is not possible to flexibly adjust the cylinder to different strip material thicknesses. Conventional configurations using servo motors allow for changing the position of the rocker arm to adjust the distance between a roller and the strip material. However, for this purpose, the servo motors are usually mounted on the rocker arm in addition to pressure cylinders.The servo motors thus generate a force that opposes the contact pressure of the pressure cylinder. This configuration is therefore very inefficient, costly, and, due to the additional components, structurally challenging and prone to failure.

[0013] One object of the present invention is therefore to overcome the disadvantages of the prior art. In particular, the present invention addresses the problem 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 which is flexibly adjustable in order to be able to process different strip materials in a material conveying device. It is generally an object of the invention to provide a pressure cylinder that is structurally simple, allows for simplified operation and automated adjustment to different strip materials, exhibits low material wear, and is cost-effective. JP2852627 also discloses a pressure cylinder for a material conveying device, in particular for a roller feed. 3. Summary of the invention

[0014] The above problems, as well as further problems arising from the following description, are solved by the subject matter of the independent claims. Preferred embodiments are the subject matter of the dependent claims, and the person 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, by means of a pressure cylinder, a corresponding material conveying device, and a method for adjusting the piston rod length of a pressure cylinder. The technical characteristics, advantages, and improvements over the prior art of the pressure cylinder described below apply equally to the material conveying device and the method. Pressure cylinder - first piston rod element rotatable relative 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 guide the piston rod at least partially; 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 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.

[0017] The pressure cylinder according to the invention makes it possible to change, and in particular to 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. Advantageously, this allows the stroke length (the distance the piston travels in the cylinder) to be kept short.

[0018] Therefore, the cylinder chamber (also understood as cylinder volume) can be designed to be small. For example, the axial length of the cylinder chamber can be short. 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 increasing the throughput of strip material. Conventional pneumatic pressure cylinders require additional components to limit the stroke length without altering the piston rod. The cylinder volume in 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 can furthermore provide an increased cycle rate. This ensures an overall more efficient processing of strip material in material conveying devices, in particular in roller feeders with progressive cutting tools, for example, punching tools.

[0020] The engagement of the piston rod with a moving component of the material conveying device can be understood as the existence of contact and, in particular, the exertion of pressure from the piston rod onto 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 the movement of the cylinder's piston. This can thus achieve intermediate ventilation. This "operation" is not necessarily to be understood as the rotary 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 partially. This can be understood to mean that the piston rod is at least partially in contact with the cylinder chamber. For example, the piston rod can be guided through the center of 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, i.e., using compressed air. The piston is connected to the piston rod. This means that the piston rod can move along with the piston. Advantageously, the connection is not a rigid one that prevents relative movement of the piston and piston rod in all directions (as further explained herein by means of a rotatable device).

[0023] The rotary motion of the first piston rod element is, for example, a rotary motion 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 rotatably mounted relative to the piston; this can be achieved, for example, by means of a bearing. Because the first piston rod element is rotatably mounted relative to the piston, its rotation does not typically result in a rotation of the piston itself. This advantageously prevents the piston from causing frictional forces against a wall of the cylinder (for example, if the piston were to rotate). Consequently, this arrangement contributes to reduced wear and facilitates adjustment of the piston rod length. Therefore, the piston rod length can be changed in a material-friendly manner, which can increase its service life.

[0026] A second embodiment of the pressure cylinder relates to the preceding 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 the piston. If either component should wear out, it is sufficient to replace the worn component. 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, particularly without significant force. The inventors have succeeded in making this possible without significant force, 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 positioned in an upper or lower position within the cylinder chamber. InIn such a position, the contact area between the piston and a wall of the cylinder can be increased (since, for example, an end face of the piston forms the contact area in addition to a cylindrical surface). Consequently, if the piston were to rotate with the first piston rod element as an integral component during a rotational movement of the first piston rod element, the frictional forces would be significantly increased. Therefore, a considerably greater force would be required. This significant disadvantage can be overcome by separating the components.

[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 inside the piston rod and which is substantially fixed to the second piston rod element.

[0030] The threaded rod can be considered a rod, i.e., an elongated component, which has at least a partial thread. The threaded rod helps to prevent unintentional rotation of the first piston rod element, as described herein. Thus, unintentional rotation could occur during operation of the pressure cylinder. The fixed connection between the threaded rod and the second piston rod element can be understood as meaning that the connection will not loosen during operation. However, both components can be detached using additional means if desired (for example, when replacing the components).

[0031] Positioning the threaded rod at least partially inside 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, which is arranged substantially in the longitudinal direction of the piston rod at one end of the piston rod, and which is configured to lock an adjustable length of the piston rod; wherein the locking device preferably comprises a screw connection which optionally engages with the threaded rod.

[0033] The locking mechanism can, for example, include a nut, a lock nut, or a knurled nut. A locking mechanism is understood as a means of securing, locking, and / or blocking moving components. The locking mechanism is typically located at one end of the first piston rod section of the piston rod. This end is usually the end facing away from the moving component of the material handling device when the pressure cylinder is inserted into the device. This arrangement offers the advantage, compared to arrangements with lateral locking mechanisms, that the components do not protrude unnecessarily beyond the lateral dimensions. Furthermore, this arrangement allows for motorized and / or automated adjustment of the piston rod length.

[0034] The locking mechanism reduces or essentially prevents any (unwanted) changes to the set piston rod length. The engagement of the threaded rod allows the distance between the locking mechanism and the second piston rod element to be kept essentially constant. This effectively prevents rotation of the first piston rod element during operation of the pressure cylinder.

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

[0036] Preferably, a handwheel can be provided which, when rotated, exerts a corresponding rotary motion 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 via a square drive. This connection is typically designed so that, during operation of the pressure cylinder, 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. Preferably, the width of the air gap is chosen to be so small that essentially no dirt can pass through it. 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 guide the piston rod at least partially; 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 rotary 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 effect the rotary movement of the first piston rod element.

[0038] In this embodiment, the inclusion of a motor is advantageous, allowing for optimized adjustment of the piston rod length. Conventional standard pneumatic cylinders do not allow for piston rod length adjustment and consequently, no motorized adjustment. The motor enables the efficient integration of a control system. Therefore, improved piston rod length adjustment can be achieved when changing the strip material. This eliminates the need for cumbersome manual adjustment, thus reducing costs. Strip material changes can be automated. The motor can be, for example, an electric motor. A servo motor, a stepper motor, or a direct current (DC) motor can all be used. The motor examples listed here are not intended to be limiting but merely serve to illustrate the concept. A wide variety of other technically suitable 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 sixth embodiment of the pressure cylinder relates to the preceding embodiment, wherein the motor is configured to cause no translational movement of the first piston rod element.

[0041] The motor is not required for the operation of the pressure cylinder described herein, particularly for intermediate ventilation. Preferably, the pressure cylinder is operated pneumatically, as described herein, thereby achieving, for example, intermediate ventilation. During operation of the pressure cylinder, a translational movement of the first piston rod element occurs. Advantageously, this movement 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 essentially in the longitudinal direction of the piston rod at one end of the piston rod.

[0043] In For example, the motor could take over the function of a handwheel for adjusting the 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 is engaged with the first piston rod element, preferably via a square connection; wherein the piston rod, in particular the first piston rod element, is arranged to be axially movable relative to the coupling; wherein preferably the piston rod, in particular the first piston rod element, is arranged to be non-rotatable relative to the coupling.

[0045] The motor can include a motor shaft. The motor can also transmit torque to the clutch, which is then transmitted to the piston rod, specifically only to the first piston rod section and not the second. During (pneumatic) operation of the pressure cylinder, the piston rod can move translationally, particularly axially, relative to the clutch and thus relative to the motor. A clearance, such as an air gap, can be provided for this purpose. The air gap can be large enough to allow for this relative translational movement.

[0046] The air gap can be small enough to transmit a rotary motion (and the torque) of the clutch to the first piston rod element.

[0047] The piston rod, in particular the first piston rod element, is not rotatable relative to the coupling. This means that the first piston rod element essentially does not rotate relative to the coupling. Consequently, any (unintentional) change in the set length of the piston rod can be reduced or essentially prevented. Therefore, in the embodiment with a motor, a locking mechanism using a nut, a lock nut, or a knurled nut is not strictly necessary.

[0048] A 9th embodiment of the pressure cylinder relates to the preceding embodiment, wherein the clutch is configured not to perform any translational movement.

[0049] During (pneumatic) operation of the pressure cylinder, the coupling typically performs no movement (neither rotary nor translational). This reduces complexity and simplifies the movement mechanisms. For example, the coupling can be considered a component that is essentially fixed in the axial direction. The same can consequently apply to the motor. Therefore, their positions during operation of the pressure cylinder are advantageously fixed, which offers benefits for the overall design. Pressure cylinder - 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 understands that the features, technical characteristics, 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, provided that 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 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, further preferably a maximum of 1.5 mm, even more preferably a maximum of 1.0 mm, further preferably a maximum of 0.7 mm, most preferably a maximum of 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, more preferably at least 0.05 mm, most preferably at least 0.1 mm.

[0053] This stroke length (the distance the piston travels within the cylinder during operation of the pressure cylinder) is significantly shorter compared to 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 handling devices can be achieved compared to conventional configurations. This allows for an increased conveying speed of strip material, enabling more efficient processing. The stroke length can be defined, for example, by the axial length of the cylinder and / or the axial length of the piston within the cylinder. Typically, a shorter axial length of the cylinder can be selected, thus reducing the stroke length and saving material.

[0054] It can be advantageous to provide a minimum stroke length and / or sometimes 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 arm) 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 rotary movement of the first piston rod element changes the length of the piston rod, preferably the rotary movement in a first direction increasing the length, and the rotary movement in a second direction decreasing the length.

[0056] The stroke length of the piston rod is short; nevertheless, strip materials of varying thicknesses can be processed by increasing or decreasing the piston rod length. The pressure cylinder according to the invention can therefore be used flexibly due to the adjustable piston rod length.

[0057] Therefore, it is not necessary to provide different pressure cylinders. One pressure cylinder is sufficient, which can meet a wide range of requirements, as described herein.

[0058] For example, increasing the piston rod length reduces the distance between two rollers in a material conveying device. Conversely, decreasing the piston rod length increases the distance between two rollers in a material conveying device.

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

[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 of 115 mm / 96 mm = 119.8% (~120%) as described herein. With these values ​​(ratios), the inventors enable the use of the pressure cylinder for a variety of roller feeds with different bore sizes.

[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 rotary motion of the first piston rod element causes a translational motion 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 arranged to cause a corresponding translational movement of the piston rod when the piston undergoes a translational movement.

[0064] When the piston performs a translational movement, the piston rod executes a corresponding, i.e., similar and / or equal, translational movement. The first and second piston rod sections 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, which is configured to detect a current position of the piston, particularly 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 a distance using a magnetic field. Advantageously, these measurements are very precise.

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

[0068] Furthermore, the measurement can serve quality assurance purposes, with evaluation possible via a control system. Additionally, by recording the current position, it can be determined whether intermediate ventilation has occurred. This is particularly advantageous at the high cycle rates of the invention. Consequently, it can be verified 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 conveying device. The measurement results could, for example, be used to indicate a potentially 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 pneumatically driven, and wherein the pressure cylinder is preferably configured such that translational movements of the piston and / or the first piston rod element are carried out exclusively pneumatically.

[0071] A pneumatic drive is a reliable technology that allows for the efficient operation, particularly of the intermediate air release, of the pressure cylinder. As described herein, the second piston rod element can also perform a translational movement due to the rotary motion of the first piston rod element. This is possible and advantageous in addition to the pneumatic drive 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 chamber is divided by the piston essentially into an upper cylinder chamber area, which communicates essentially exclusively with the upper air connection, and preferably into a lower cylinder chamber area, which communicates essentially exclusively with the lower air connection.

[0073] The air connection can be used to provide pressure in the cylinder chamber, which causes the piston to move. It is advantageous to have two air connections, each communicating with a specific area of ​​the cylinder chamber. This communication allows for air exchange, enabling compressed air to be introduced precisely into each area.

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

[0075] The upper cylinder chamber, when the pressure cylinder is operating correctly, can be considered such that, when pressurized, the piston and piston rod increase the contact pressure. Conversely, the lower cylinder chamber, when the pressure cylinder is operating correctly, can be considered such that, when pressurized, the piston and piston rod decrease the contact pressure. For example, the upper cylinder chamber can be arranged vertically above the lower cylinder chamber.

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

[0077] The stroke length can be individually and flexibly adjusted using the spacer disc. In For example, the stroke length of the piston can be reduced from 2.7 mm to 0.7 mm using a spacer washer with a thickness of 2.0 mm. InIn another example, the piston stroke length of 2.5 mm can be reduced to 0.5 mm using a 2.0 mm thick spacer. This allows for advantageously higher cycle rates. Compared to the prior art, which uses pressure cylinders with stroke lengths of 10 mm, this offers significant advantages.

[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 area.

[0079] The thickness can be understood as the axial dimension of the spacer. The spacer can, for example, have a shape corresponding to the shape of the cylinder chamber. The spacer is typically cylindrical. Usually, the radius of the spacer is significantly larger than its thickness, for example, by a factor of at least 3, 5, or 8. When positioned within the cylinder chamber, the spacer can also make at least partial contact with a lateral surface of the cylinder chamber. For assembly purposes, it can be advantageous for the spacer to have 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, sliding bearings which are / are configured to receive the piston rod; and an upper cylinder component and a lower cylinder component which are rigidly connected to each other and which comprise the cylinder chamber, preferably enclosing the cylinder chamber 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 projects 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 areas. For example, the upper cylinder component can be arranged vertically above the lower cylinder component.

[0082] The airtight seal means that there is essentially no pressure loss during operation of the pressure cylinder. It is understood that some (planned) air exchange still occurs via the air inlets. Air exchange between the lower and upper cylinder chambers 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, and wherein preferably the first piston rod element and the second piston rod element are arranged coaxially.

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

[0086] When the piston rod length is increased, the portion of the second piston rod element located in the cavity is reduced. Conversely, when the piston rod length is reduced, the portion of the second piston rod element located in the cavity is increased.

[0087] In one example, if 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%, more preferably at least 20%, further preferably at least 25%, even more preferably at least 30%, most preferably at least 35% of the length of the second piston rod element; and / or a maximum of 80%, preferably a maximum of 70%, more preferably a maximum of 60%, more preferably a maximum of 50%, even more preferably a maximum of 45%, most preferably a maximum of 40% of the length of the second piston rod element.

[0088] In another example, if 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%, more preferably at least 40%, more preferably at least 50%, even more preferably at least 60%, most preferably at least 65% of the length of the second piston rod element; and / or a maximum of 95%, preferably a maximum of 90%, more preferably a maximum of 85%, more preferably a maximum of 80%, even more preferably a maximum of 75%, most preferably a maximum of 70% of the 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 is because the possible variation in piston rod length must be large enough to accommodate a wide range of strip material thicknesses. At the same time, sufficient stability of the piston rod must 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 includes 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 arm, which is configured to cause a translational movement of a roller of the material conveying device when moved.

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

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

[0095] In the During operation of the pressure cylinder, the pressure can be transferred from the pressure cylinder to a rocker arm. The rocker arm is preferably a movable rocker arm, which then transmits 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 arranged such that the rotary movement of the first piston rod element does not cause essentially any 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 advantageous because otherwise the rotational movement described herein might be more difficult. Furthermore, the rotational movement of the first piston rod element serves only to move, or shift, the second piston rod element translationally.

[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 component wears out, only the worn part 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, and wherein the translational movements preferably run substantially perpendicular to a material which is to be conveyed by the material conveying device.

[0101] The translational movements can include the translational displacement / movement and / or axial displacement / movement described herein. Preferably, the translational movements are vertical, assuming the pressure cylinder is functioning correctly.

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

[0103] This offers the advantage that the pressure cylinder can be operated, for example, over its entire stroke length. Preferably, the piston does not move during the stroke, with a reversal of movement occurring in a central axial region of the cylinder chamber. The axial length can be considered parallel to the translational direction of movement (as described herein). Therefore, a separate component is not necessarily required, which 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 being 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 understands that the technical characteristics, advantages, and improvements shown herein for the pressure cylinder also apply 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 cause a translational movement of the roller towards a material to be conveyed by the material conveying device; wherein the piston rod of the pressure cylinder is further configured to decrease pressure on the rocker in order to cause a translational movement of the roller away from the material to be conveyed by the material conveying device.

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

[0109] During operation of the pressure cylinder, intermediate ventilation can occur (in this embodiment, this is understood as an increase / decrease in pressure). Intermediate ventilation serves, for example, to lift a roller after each feed cycle of the strip material in order to release the strip material for a progressive cutting tool. The rocker arm can be configured so that when the pressure on the rocker arm decreases (for example, when the pressure on a surface of the piston is reversed, i.e., when the piston moves upwards), the rocker arm moves 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 towards the material can be understood, for example, as vertically downwards. The direction of movement away from the material can be understood, for example, as vertically upwards.

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

[0112] The piston rod length can be adjusted, for example, to change the basic position of the rocker arm and / or the roller. As described herein, the rotary movement in the first direction increases the length of the piston rod. Consequently, the distance between the piston rod, rocker arm, and / or roller and the strip material can be reduced. As described herein, the rotary movement in the second direction decreases the length of the piston rod. Consequently, the distance between the piston rod, rocker arm, and / or roller and the 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 decrease is pneumatically carried out; wherein the rotary movement is not pneumatically carried out.

[0114] A 30th embodiment of the invention relates to a method for adjusting the 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; stopping the rotation in the first direction when contact or a predefined distance is reached between a movable component of the material conveying device and the material;Optionally, rotating the first piston rod element in a second direction, preferably once contact has been achieved, to effect an opposite translational movement of the second piston rod element.

[0115] Depressurization allows the piston to move in one direction, for example upwards, preferably all the way upwards. This places the piston at the top of the cylinder chamber. This facilitates adjusting the piston rod length, for example, when working with thick strip material.

[0116] Rotation in the first direction can also be stopped once a predefined distance is reached. This distance can be, for example, an axial, preferably a 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. Rotation in the first direction is advantageously performed with the aid of the motor. This rotation can be automated until contact is achieved between the roller and the strip material. This contact can be detected, for example, by an increased current draw of the motor. It is also possible to detect the contact using a sensor, preferably located in the cylinder chamber. This sensor can be an eddy current sensor.

[0118] A rotation in the second direction can then be performed. This rotation in the second direction should preferably only occur to the extent necessary to release the strip material. Advantageously, the distance between the roller and the strip material should be small enough that sufficient pressure can be built up between the roller and the strip material during a translational movement of the piston over its stroke (during operation of the pressure cylinder). This pressure should be sufficient to provide enough traction for a feed movement of the strip material. The pressure can vary depending on the strip material and can be adjusted via a pressure regulator. A pressure in the range of 1.5 bar to 8 bar is conceivable, preferably in the range of 2 bar to 6 bar.

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

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

[0121] This offers the advantage that the piston rod can be adjusted to a reduced length, preferably to the shortest possible length. Consequently, this makes it possible to convey strip material of considerable thickness. 4. Brief description of the characters

[0122] Preferred embodiments are described below only by way of example. Reference is made to the following accompanying figures: Fig. 1 shows a pressure cylinder in a material conveying device according to one 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 , wherein the piston rod is extended; Fig. 2c shows the pressure cylinder similarly according to Fig. 2a , whereby the piston is moved translationally downwards (the length of the piston rod is opposite 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 another 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 , wherein the piston rod is 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 one 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 one embodiment of the present invention. 5. Detailed description of the figures Definitions

[0123] One Rotational movement, Rotation and twisting can be considered synonymous in this context.

[0124] One Stroke length can also be understood as a path length, in particular as a total path length, that the piston travels in the cylinder chamber during operation of the pressure cylinder. This can also be understood as piston stroke This can be interpreted in various ways. For example, it could be the axial length between the piston and the wall of the cylinder chamber. InIn some cases, the stroke length, as is preferred herein, may correspond to the total axial length of the cylinder space (less a portion occupied by the piston).

[0125] The pressure cylinder The present invention can also be understood as an intermediate air cylinder. The pressure cylinder should by no means be understood restrictively in the sense that the pressure cylinder necessarily causes a pressing action. However, the pressure cylinder is intended to be suitable for a material conveying device and therefore differs, for example, from cylinders that are typically used in the operation of motor vehicles and / or piston engines. Character description

[0126] In theOnly a few possible embodiments of the invention are described in detail below. However, the present invention is not limited to these, and a multitude of other embodiments are applicable without deviating from the scope of the invention. The presented embodiments can be modified and combined with one another in numerous ways, provided 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] InThe same reference symbols refer to the same elements in all the figures and descriptions presented here. It is understood that the reference symbols (100-199) of the figures of the first aspect also apply to the figures of the second aspect (with reference symbols 200-299) and are omitted 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 Figure 1 shows a pressure cylinder 100, 200 (hereafter the reference numeral 200 is not listed separately, but is also intended to 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 only indicated by a reference symbol) convey in the conveying direction F.

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

[0131] The piston rod 110 comprises a first piston rod element 111 and a second piston rod element 112, which are arranged 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 arm 2, causing a translational movement of the roller 5 towards a strip material 10 that is to be conveyed by the material conveying device 1. The rocker arm 2 can rotate about the pivot point 3. The piston rod 110 of the pressure cylinder 100 is also configured to decrease pressure on the rocker arm 2, causing 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 of the pressure is achieved by means of pneumatic operation of the drive cylinder 100 and can occur during intermediate ventilation, for example at a minimum of 1500 strokes / min, 2000 strokes / min, or 2500 strokes / min.

[0133] In this example arrangement, the direction towards material 10 can be understood as vertically downwards. The direction away from material 10 can be understood as vertically upwards.

[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, and most preferably from 0.1 mm to 5 mm can be processed.

[0135] Fig. 2 Figure 1 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 each other, for example by a screw connection. The two cylinder components 140 and 145 essentially enclose the cylinder chamber (not shown) in an airtight manner.

[0137] The pressure cylinder 100 also includes 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 includes a releasable locking device 170, which is arranged essentially longitudinally along the piston rod (only the second piston rod element 112 of the piston rod is shown) at one end of the piston rod. The locking device 170 is designed to lock an adjustable length of the piston rod. The locking device 170 includes a knurled nut 171, which engages with the threaded rod (not shown). The pressure cylinder 100 includes a handwheel 180, which, when rotated, exerts a corresponding rotary motion on the first piston rod element (not shown).

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

[0140] The first piston rod element 111 and the second piston rod element 112 are shown. 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 port 141, and a lower cylinder chamber region 147, which communicates essentially exclusively with the lower air port 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 comprises two sliding bearings 150, which are designed to receive the piston rod 110. In particular, the first piston rod element 111 is received by the two sliding bearings 150.

[0143] The pressure cylinder 100 comprises a threaded rod 160, which is arranged at least partially inside the piston rod 110, in particular inside the first piston rod element 111. The threaded rod 160 is essentially rigidly 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 projects through the washer 172. Thus, the threaded rod 160 is located within the first piston rod element 111 and the knurled nut 171. The knurled nut 171 can be screwed onto the upper thread 161 of the threaded rod 160 and then lock the rotational position of the handwheel 180. This advantageously prevents, for example, the set length of the piston rod 110 from changing during operation of the pressure cylinder 100.

[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, projects at least partially beyond the lower cylinder component 145.

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

[0148] This figure shows an arrangement in which the length Lo of the piston rod 110 is extended. A comparison with the previous figure clarifies that the second piston rod element 112 is translationally displaced (axially downwards in the figure). A rotational movement of the first piston rod element 111 causes a change in the length of the piston rod 110. The rotational movement in a first direction increases the length Lo, and the rotational movement in a second direction decreases the length Lo. The first and second directions are opposite. The rotational movement is achieved 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 rotational 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 corresponding rotational movement on the first piston rod element 111. This facilitates the adjustment of the piston rod length 111, as it has a larger radius than the first piston rod element 111 and thus requires less force for a constant torque. The connection between the handwheel 180 and the first piston rod element 111 can be provided via a square drive.

[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] If the length L0 of the piston rod 110 is set to a minimum length (similar to in Fig. 2c), the part L2 arranged in cavity 113 (the marking is in Fig. 2c (as can be seen) 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] If the length L0 of the piston rod 110 is set to a maximum length L0 (similar to in Fig. 2b ), the part L2 arranged in cavity 113 (the marking is in Fig. 2c (as can be seen) 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 L0 of the piston rod 110, which is set to a maximum length ( Fig. 2b) to the length L0 of the piston rod 110, which is set to a minimum length ( Fig. 2c The graph shows values ​​in the range of 110% to 150%. In this example, the value is 120%, meaning the piston rod 110 can be advantageously extended by 20% of its minimum length. Expressed in absolute terms, the maximum length L0 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 , whereby the piston 130 is moved downwards. Furthermore, the length L0 of the piston rod 110 is reduced to a minimum (in Fig. 2a (the length L0 of the piston rod 110 is not yet completely reduced to a minimum).

[0155] In the (pneumatic) operation of the pressure cylinder 100, the air connections serve to provide pressure in the cylinder chamber 120, which causes the piston 130 to move within the cylinder chamber 120. The figure shows the position of the piston 130 at a lower end of the cylinder chamber 120. Therefore, the lower cylinder chamber region 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 region 142.

[0156] In the (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 venting). 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 the axial length of the cylinder chamber 120. In particular, the stroke length L3 can be described, as shown, by means of the (axial) distance between the piston 130 and the upper end of the cylinder chamber 120. Thus, according to this figure, the stroke length L3 is defined by the axial length of the upper cylinder chamber region 142.

[0158] Advantageously, the cylinder chamber 120 has a short axial length (or, as can be seen here, the upper cylinder chamber area 142), so that the stroke length L3 can be kept short. Consequently, a higher 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 total axial length is represented by the stroke length L3.

[0160] Fig. 3Figure 1 shows a pressure cylinder 200, 100 (hereinafter referred to simply as 200) according to a second aspect of the present invention in a perspective view. Those skilled in the art will understand that, accordingly, 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 strictly necessary. In the second aspect, the first piston rod element 111 can advantageously be rotatably arranged relative to the piston 130 (or the piston 130 can be rotatably arranged 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, thereby substantially preventing rotation of the second piston rod element 112 when the first piston rod element 111 rotates. The fixing component projects laterally, at least partially, beyond a side surface of the piston rod. The fixing component can engage 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, the installation position of the second piston rod element 112 within a movable component 2 of the material conveying device 1 can also substantially prevent rotation of the second piston rod element 112 when the first piston rod element 111 rotates.

[0162] The pressure cylinder also includes a motor 280, which is designed to effect the rotary 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-locking 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, whose designations are known to those skilled in the art from, among other things, Fig. 2-2c They are not listed again for clarity and are not included in the overview.

[0166] The motor 280 further comprises a coupling 281, which is essentially rigidly connected to a motor shaft 282 of the motor 280, the coupling 281 being engaged with the first piston rod element 111. The piston rod 110, in particular the first piston rod element 111, is arranged to be axially movable relative to the coupling 281. The piston rod 110, in particular the first piston rod element 111, is arranged to be non-rotatable relative to the coupling 281. Thus, the two components are essentially non-rotatably connected (via the square connection described herein). The coupling 281 can therefore prevent an (unwanted) rotational movement of the first piston rod element 111 and / or cause a (wanted) rotational movement of the first piston rod element 111. Consequently, an (unwanted) change in a set length L0 of the piston rod 110 can be essentially prevented.

[0167] Fig. 3c shows the pressure cylinder 200 according to Fig. 3b, wherein the piston rod 110 is extended. For an understanding of the reference numerals in this figure, the corresponding descriptive passages of the Fig. 2b In particular, the person skilled in the art understands the change in the length L0 of the piston rod 110 between Fig. 3b and Fig. 3c using the change in the length L0 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 rotary movement of the first piston rod element 111 is caused by the motor 280.

[0169] If the length L0 of the piston rod 110 is set to a minimum length (similar to in Fig. 3b or Fig. 3d), the part L2 of the second piston rod element 112 arranged in the cavity 113 shall be at least 20% and / or at most 95%, preferably at least 30% and / or at most 90%, for example 66% of the length L1 of the second piston rod element 112.

[0170] When the length L0 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 shall be at least 5% and / or at most 80%, preferably at least 10% and / or at most 70%, for example 36% of the length L1 of the second piston rod element 112.

[0171] A comparison of the length L0 of the piston rod 110, which is set to a maximum length ( Fig. 3c ) to the length L0 of the piston rod 110, which is set to a minimum length ( Fig. 3b and Fig 3d), shows values ​​in the range of 110% to 150%. In this example, the value is 120%, so the piston rod 110 can be advantageously extended by 20% of its minimum length.

[0172] Fig. 3d shows the pressure cylinder 200 according to Fig. 3b , whereby the piston is moved downwards. The length L0 of the piston rod 110 is as in Fig. 3b reduced to a minimum. The ratio of length L2 to L1 is therefore at its greatest.

[0173] Similar to in Fig. 2c described, is in Fig. 3d The piston 130 is shown in a lower position. This is achieved by the pneumatic operation of the pressure cylinder 200, which moves the piston 130 downwards (by pressurizing a lower air port, the piston 130 can be moved upwards accordingly). The relevant descriptions apply. Fig. 2c likewise for Fig. 3d .

[0174] Fig. 4 Figure 1 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 121, which is arranged in the cylinder chamber 120. The spacer 121 has a thickness of at most 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 is 0.7 mm in this example (2.7 mm without the spacer 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 represent an intermediate air gap of 0.7 mm provided by the pressure cylinder 100, 200.

[0176] The spacer 121 is arranged on an upper wall of the upper cylinder chamber area 141 (not separately marked), this wall coinciding 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 by a lower wall of the upper cylinder component 140 (or a spacer 121, as described herein) and an upper wall of the lower cylinder component 145.

[0178] For example, the pressure cylinder can enable 100, 200, at least 1500 strokes / min, or at least 2000 strokes / min. This advantageously provides high cycle rates. In one example, the amount of time available to execute the stroke could also be relevant. This can be influenced by an intermediate air gap angle and / or a required (air) pressure: The intermediate air gap angle can affect the time available to execute an intermediate air gap stroke (i.e., moving the piston upwards and downwards). For example, an intermediate air gap angle of 60° (assuming 500 strokes / min, which equates to 0.12 seconds / stroke) means that only 360° / 60° = 1 / 6 of the time is available to execute an intermediate air gap stroke (0.12 seconds / stroke / 6 = 0.02 seconds / stroke). Consequently, in one example, higher clock rates (higher stroke / min) can be executed at higher intermediate air angles (since more time is available).This example is for illustrative purposes only and should not be interpreted as restrictive.

[0179] The effect of pressure can be understood as follows: The lower the required air pressure, the faster the cylinder can be filled. If a higher air pressure is required, a larger volume of air must be introduced into the cylinder, since, under simplifying assumptions, air can be compressed according to the ideal gas law.

[0180] Fig. 5 shows the pressure cylinder 100, 200 according to a further 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 the current position of the piston 130 in the cylinder chamber 120. The sensor 155 is configured to detect the distance between the sensor 155 and the underside of the piston 130.

[0182] The principle of 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, especially of electrically conductive components, can be determined.

[0183] Fig. 6Figure 1 shows a schematic flowchart of a method 1000 for adjusting the length L0 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 of the pressure cylinder 100, 200; optionally rotating 1200 of the first piston rod element 111 in the second direction; introducing 1300 of material 10, in particular strip material, into the material conveying device 1; rotating 1400 of 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; The rotation stops at 1500 when contact or a predefined distance is reached between a moving component 2, 5 of the material conveying device 1 and the

[0184] Material 10 is reached; optionally, rotate 1600°, preferably when contact has been reached, of the first piston rod element 111 in a second direction to effect an opposite translational movement of the second piston rod element 112.

[0185] In the above explanations, it can be particularly advantageous that, with thick strip material 10, the piston rod length 110 is usually reduced. With thin strip material 10, the piston rod length 110 is usually increased.

[0186] The pressure (contact pressure) provided during operation of the pressure cylinder (for intermediate ventilation) can sometimes depend on the belt material, in particular the surface of the belt material, the acceleration of the material conveying device on the belt material and a variety of other parameters.

[0187] The scope of protection is determined by the patent claims and is not limited by the exemplary embodiments and / or figures. 6. List of reference symbols

[0188] 1 Material conveying device, in particular roller feed 2 Rocker 3 Pivot point of the rocker 5, 6 Roller 10 Strip material F Conveying direction of the strip material L0 Length of the piston rod L1 Length of the second piston rod element L2 Part of the second piston rod element that is arranged in the cavity of the first piston rod element L3 Stroke length 100,200 Pressure cylinder 110 Piston rod 111 First piston rod element 112 Second piston rod element 113 Cavity of the first piston rod element 115 Thread 120 Cylinder chamber 121 Spacer 130 Piston 140 Upper cylinder component 141 Upper air connection 142 Upper cylinder chamber area 145 Lower cylinder component 146 Lower air connection 147 Lower cylinder chamber area 150 Plain bearing 155 Sensor 160 Threaded rod 161 Upper thread of the threaded rod 162 Lower thread of the threaded rod 170 Locking device 171 Knurled nut 180 Handwheel 280 Motor 281 Clutch 282 Motor shaft 1000 Procedure 1100 Procedure step: optional pressure release 1200 Procedure step: optional rotation in a second direction 1300 Process step: Introducing material 1400 Process step: Rotating in a first direction 1500 Process step: Ending the rotation 1600 Process step: Optionally rotating in a second direction

Claims

1. Pressing cylinder (100, 200) for a material conveying device (1), in particular for a roller feed, comprising: a piston rod (110) which is configured to come into engagement with a movable component (2, 5) of the material conveying device (1); a cylinder chamber (120) which is configured to guide the piston rod (110) at least in part; and a piston (130) which is arranged movably in the cylinder chamber (120) and which is connected to the piston rod (110); characterized in that 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) brings about 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 with respect to the piston (130).

2. The pressing 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 pressing cylinder (100, 200) according to either of the preceding claims, further comprising: a threaded rod (160) which is arranged at least in part within the piston rod (110) and which is connected substantially fixedly to the second piston rod element (112).

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

5. The pressing cylinder (100, 200) according to one of the preceding claims, wherein the piston rod (110) is configured to execute a stroke length (L3) of at most 5.0 mm, preferably at most 3.0 mm, further preferably at most 2.5 mm, even further preferably at most 2.0 mm, further preferably at most 1.5 mm, even further preferably at most 1.0 mm, further preferably at most 0.7 mm, most preferably at most 0.5 mm; and / or wherein the piston rod (110) is configured to execute a stroke length (L3) 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.

6. The pressing cylinder (100, 200) according to one of the preceding claims, wherein the rotational movement of the first piston rod element (111) changes a length (L0) of the piston rod (110), wherein preferably the rotational movement increases the length (L0) in a first direction, and the rotational movement decreases the length (L0) in a second direction.

7. The pressing 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 in engagement via a screw contact (115), in particular a thread.

8. The pressing cylinder (100, 200) according to one of the preceding claims, wherein the piston (130) is configured to bring about a corresponding translational movement of the piston rod (110) during a translational movement of the piston (130).

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

11. The pressing cylinder (100, 200) according to one of the preceding claims, further comprising: a spacer disk (121) which is arranged in the cylinder chamber (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 pressing 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 in part within the cavity (113), wherein preferably the first piston rod element (111) and the second piston rod element (112) are arranged coaxially.

13. The pressing cylinder (100, 200) according to one of the preceding claims, wherein the pressing 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 pressing cylinder (100, 200) according to one of the preceding claims.

15. Method (1000) for adjusting a piston rod length of a pneumatic pressing cylinder (100, 200) in a material conveying device (1), in particular of a pressing cylinder (100, 200) according to one of Claims 1 to 14, comprising: optionally depressurizing (1100) the pressing 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 pressing cylinder (100, 200) in a first direction in order to bring about a translational movement of a second piston rod element (112) of the piston rod (110) of the pressing cylinder (100, 200); ending the rotation (1500) when a contact or a predefined distance between a movable component (2, 5) of the material conveying device (1) and the material (10) has been reached; optionally rotating (1600), preferably when a contact has been reached, the first piston rod element (111) in a second direction in order to bring about an opposite translational movement of the second piston rod element (112).