EP4331843A1 - Pressing cylinder for a material conveying device - Google Patents

Abstract

The present invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, comprising: a piston rod which is designed to come into engagement with a movable component of the material conveying device; a cylinder space which is designed to at least partially guide the piston rod; a piston which is arranged in the cylinder space and which is in communication with the piston rod; and an engine; wherein the piston rod includes a first piston rod member and a second piston rod member configured such that rotational movement of the first piston rod member causes translational movement of the second piston rod member relative to the piston; wherein the motor is adapted to effect the rotational movement of the first piston rod element.

Description

1. Technical area

The present invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, the pressure cylinder comprising a piston rod, the length of the piston rod being adjustable.

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

Material conveying devices, in particular roller feeds, are used, for example, for conveying and advancing, in particular for the clocked advancing of workpieces, such as strip material or strip material. For example, roller feeds are used in punching applications. The workpiece is advanced in a clocked manner, with the timing of the feed being synchronized with a punching tool.

Roller feeds are also known from other areas of application. For example, a roller feeder can have a profiled roller and emboss or punch the corresponding profile into the workpiece when the workpiece is advanced.

The principle of 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.

At least one of the rollers is a powered roller. To advance/convey, the workpiece is introduced into a gap formed between the rollers. The workpiece is then advanced/conveyed by synchronous rotation of the rollers. The speed of rotation of the rollers determines the conveying or feed speed.

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

On the one hand, pressure cylinders are intended to apply contact pressure to a roller, for example to the upper roller. This contact pressure makes it possible to transport a strip material introduced into the material conveying device with as little slip as possible. Usually, the pressure from the pressure cylinder is applied to a movable rocker, which then passes on the pressure to the roller. The rocker can rotate via a pivot point.

Pressure cylinders should also be able to raise the roller in order to be able to introduce new strip material. This lifting occurs, for example, by moving a piston upwards in the cylinder, causing the rocker and the upper roller to move upwards.

Pressure cylinders should also enable intermediate ventilation, which can also be referred to as “letting go”. The intermediate ventilation causes the roller to be raised after each feed cycle of the strip material in order to release the strip material for a subsequent cutting tool. The subsequent cutting tool, for example a punching tool, can be centered better in this way and aligned with holes that have already been punched in advance. For example, band materials can be aligned via pilot pins using pre-punched pilot holes through intermediate ventilation.

In order to fulfill the functions described above, at least the following requirements are placed on a pressure cylinder. For example, the number of cycle cycles (also feed cycle cycles) per unit of time represents a significant parameter in material conveying devices. A cycle cycle is the process of raising and lowering the piston in the pressure cylinder (a stroke). The number of clock cycles per unit of time is also to be understood as the clock rate and is usually expressed as stroke/min. Increased Clock rates can significantly increase the efficiency of material conveying devices. The cycle rates of the pressure cylinder should therefore be increased. In addition, a variety of different material thicknesses of strip material should be able to be processed. In addition, the structure should be structurally simple and cost-effective.

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 is also noticeable. Malfunctions occur more frequently, which is why the overall configuration is cost-intensive. It is also 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 to adjust the distance between a roller and the strip material. However, the servo motors are usually attached to the rocker in addition to pressure cylinders. The servo motors thus exert a force that is opposite to the contact pressure of the pressure cylinder. This configuration is therefore very inefficient, cost-intensive and, due to the additional components, is structurally challenging and prone to failure.

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 task of providing a pressure cylinder for a material conveying device, the pressure cylinder enabling an increased cycle rate. In addition, a pressure cylinder should be provided, which can be flexibly adjusted 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 belt materials, has little material wear and is inexpensive.

3. Summary of the invention

The above tasks as well as further tasks arising from the following description are solved by the subject matter of the independent claims. Preferred embodiments are the subject 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.

The aims and tasks of the present invention are achieved, among other things, with a pressure cylinder, as well as a corresponding material conveying device, and a method for adjusting a piston rod length of a pressure cylinder. The technical properties shown below for the pressure cylinder, the advantages of the pressure cylinder and the improvements compared to the prior art also apply to the material conveying device and the method.

Pressure cylinder - first piston rod element rotatable to the piston

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 which is designed to come into engagement with a movable component of the material conveying device; a cylinder space which is designed to at least partially guide the piston rod; and a piston movably arranged in the cylinder space and in communication with the piston rod; wherein the piston rod includes a first piston rod member and a second piston rod member configured such that rotational movement of the first piston rod member causes translational movement of the second piston rod member relative to the piston; wherein the first piston rod element is rotatable relative to the piston.

The pressure cylinder according to the invention makes it possible to change, in particular to adjust, a length of the piston rod. This should therefore be understood to mean that the length of the piston rod is changed relative to the piston. The length of the piston rod can therefore be adjusted largely independently of the position of the piston. This advantageously allows the path length that the piston travels in the cylinder chamber (stroke length) to be made small.

The cylinder space (also to be understood as the cylinder volume) can therefore be made small. For example, an axial length of the cylinder space can be small. The clock rate (expressed in strokes/min) can therefore be significantly increased compared to the prior art. For example, cycle rates of at least 1000 strokes/min, preferably at least 1500 strokes/min, 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 a stroke length without changing the piston rod. The cylinder volume is still large with these conventional pressure cylinders, which is disadvantageous and inefficient.

The pressure cylinder according to the invention can also be flexibly adjusted for different thicknesses of strip material and can also provide an increased cycle rate. This ensures an overall more efficient processing of strip material in material conveying devices, especially in roller feeds with follow-up cutting tools, for example punching tools.

The engagement of the piston rod with a movable component of the material conveying device can be understood to mean that there is contact and in particular a pressure is applied by the piston rod to the movable component of the material conveying device during operation of the pressure cylinder in order to move the movable component. The “operation” of the pressure cylinder is to be understood as meaning that the piston of the cylinder moves. Intermediate ventilation can therefore be achieved. This “operation” is not necessarily to be understood as referring to 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 cannot be ruled out that the latter also occurs during operation.

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 centrally through the cylinder chamber.

The piston is usually moved in the cylinder space during operation of the pressure cylinder, preferably it is moved up and down. The operation can be carried out pneumatically, 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 which prevents relative movement of the piston and the piston rod to one another in all directions (as further set out herein by a rotatable device).

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.

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.

The first piston rod element is rotatable relative to the piston; This can be made possible, for example, by storage. Since the first piston rod element is designed to be rotatable relative to the piston, the rotational movement of the first piston rod element usually does not lead to a rotational movement of the piston. This can advantageously prevent the piston from causing frictional forces on a wall of the cylinder space (for example if the piston were to rotate). Consequently, the arrangement contributes to low wear and facilitates adjustment of the piston rod length. The length of the piston rod can therefore be changed in a way that protects the material, which can increase longevity.

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.

This allows the piston rod length to be adjusted without affecting the piston, for example without moving the piston. If one of the two components becomes worn, simply replacing the worn component is sufficient. The component that is not worn can still be used. This saves material and reduces costs.

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 space. In such a position, the contact surface 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 amount of force would be necessary. This significant disadvantage can be overcome through separation.

A 3rd embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a threaded rod which is at least partially arranged within the piston rod and which is essentially firmly connected to the second piston rod element.

The threaded rod can be understood as a rod, i.e. an elongated component, which at least partially has a thread. The threaded rod may help prevent inadvertent rotational movement of the first piston rod member as described herein. An unintentional rotational movement could therefore occur during operation of the pressure cylinder. The firm connection between the threaded rod and the second piston rod element can be understood to mean that the connection does not come loose during operation. However, both components can be solved using additional means if this is desired (for example when replacing the components).

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

A 4th embodiment of the pressure cylinder relates to one of the previous embodiments, further comprising: A releasable lock, which is in Is arranged essentially in the longitudinal direction of the piston rod at one end of the piston rod, and is designed to lock an adjustable length of the piston rod; wherein the lock preferably comprises a screw connection, which optionally engages with the threaded rod.

The lock can include, for example, a nut, a lock nut or a knurled nut. A locking is to be understood as a locking, locking and/or blocking of moving components. The lock is arranged in particular at one end of the first piston rod element of the piston rod. This end is typically the end which faces away from the movable component of the material conveying device when the pressure cylinder is used in the material conveying device. This arrangement, for example, has the advantage over arrangements with lateral locks that the components do not protrude unnecessarily beyond the lateral dimensions. This arrangement also enables a motorized and/or automated adjustment of the length of the piston rod.

By locking, an (unintentional) change in a set length of the piston rod length can be reduced or essentially prevented. By engaging with the threaded rod, a distance between the lock and the second piston rod element can be kept essentially constant. In this way, a rotational movement of the first piston rod element during operation of the pressure cylinder is advantageously essentially prevented.

A washer can be arranged between the lock and the piston rod. The threaded rod can protrude through the washer.

Preferably, a handwheel can be provided which, during a rotary movement, exerts a correspondingly rectified rotary movement on the first piston rod element. This can make adjusting the piston rod length easier. The connection between the handwheel and the first piston rod element can be made possible via a square connection. This connection is usually designed in such a way that when the pressure cylinder is in operation, the handwheel moves translationally together with the piston rod and the piston (e.g. during intermediate ventilation). For this purpose one can 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 in its gap width that essentially no dirt gets through the air gap.

Pressure cylinder - with motor

A 5th embodiment of the invention relates to a pressure cylinder for a material conveying device, in particular for a roller feed, comprising: a piston rod which is designed to come into engagement with a movable component of the material conveying device; a cylinder space which is designed to at least partially guide the piston rod; a piston which is arranged in the cylinder space and which is in communication with the piston rod; and an engine; wherein the piston rod includes a first piston rod member and a second piston rod member configured such that rotational movement of the first piston rod member causes translational movement of the second piston rod member relative to the piston; wherein the motor is adapted to effect the rotational movement of the first piston rod element.

In this embodiment, a motor is advantageously included, with which the adjustment of the piston rod length can be optimized. Conventional standard pneumatic cylinders do not allow adjustment of the piston rod length and therefore no motorized adjustment. The motor enables sensible integration of a control system. This means that an improved adjustment of the piston rod length can be achieved when changing the band material. In this way, laborious manual adjustment can be dispensed with to reduce costs. 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 engines listed herein are in no way intended to be limiting, but are intended for understanding purposes only. A variety of other technically useful engines can be used.

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

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

The motor does not have to be required for the operation of the pressure cylinder described herein, in particular for intermediate ventilation. Preferably, the operation of the pressure cylinder is pneumatic, as described herein, whereby, for example, intermediate ventilation is achieved. During operation of the pressure cylinder, a translational movement of the first piston rod element takes place. This advantageously does not have to be provided by the engine.

A 7th embodiment of the pressure cylinder relates to one of the previous 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.

In one example, the motor could take on the function of a handwheel for adjusting a piston rod length.

An 8th embodiment of the pressure cylinder relates to one of the previous 5th to 7th embodiments, further comprising: a coupling which is essentially firmly connected to a motor shaft of the engine, the coupling being in engagement with the first piston rod element, preferably via a square connection ; wherein the piston rod, in particular the first piston rod element, is designed to be axially movable in relation to the coupling; wherein preferably the piston rod, in particular the first piston rod element, is designed to be non-rotatable for the coupling.

The motor may include a motor shaft. The motor can also transmit a torque to the clutch, which is then transmitted to the piston rod, in particular only to the first piston rod element and not to the second piston rod element. During (pneumatic) operation of the pressure cylinder, the piston rod can move translationally, in particular axially, relative to the clutch and thus relative to the motor. For this purpose, a clearance, for example an air gap, can be provided. The air gap can be large enough to allow relative translational movement.

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

The piston rod, in particular the first piston rod element, is not designed to be rotatable for the coupling. This is to be understood as meaning that the first piston rod element essentially does not rotate relative to the clutch. Consequently, an (unintentional) change in a set length of the piston rod can be reduced or essentially prevented. In the embodiment with a motor, locking using a nut, a lock nut or a knurled nut is therefore not absolutely necessary.

A 9th embodiment of the pressure cylinder relates to the previous embodiment, wherein the clutch is designed not to carry out a translational movement.

During (pneumatic) operation of the pressure cylinder, the coupling usually does not carry out any movement (both no rotary movement and no translational movement). This reduces complexity and simplifies the movement mechanisms. For example, the coupling can be viewed as a component that is essentially fixed in the axial direction. The same can therefore apply to the engine. Thus, their positions during operation of the pressure cylinder are essentially firmly determined, which brings advantages for the arrangement.

Pressure cylinder - general embodiments

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

The person skilled in the art understands that the features, the technical properties, the advantages and the 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 this makes technical sense.

An 11th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston rod is designed 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 preferred a maximum of 1.5 mm, more preferably a maximum of 1.0 mm, more preferably a maximum of 0.7 mm, most preferably a maximum of 0.5 mm; and/or wherein the piston rod is designed 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.

This stroke length (distance length that the piston performs in the cylinder chamber when the pressure cylinder is operating) is significantly smaller than the prior art. Consequently, a significant increase in the cycle rates (stroke/min or number of strokes per minute) of the pressure cylinder for material conveying devices can be achieved compared to conventional configurations. This means that the conveying speed of strip material can be increased, enabling more efficient processing of strip material. The stroke length can be defined, for example, by an axial length of the cylinder space and/or by an axial length of the piston in the cylinder space. Typically, a small axial length of the cylinder chamber can be selected so that the stroke length is reduced. This saves material.

It can be advantageous to provide a minimum stroke length and/or sometimes a larger stroke length. This can occur, for example, with wider roller feeds and/or when movable components of the roller feed (e.g. a rocker) are flexible and/or when flexible strip materials (e.g. plastics) are to be conveyed. Yield 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.

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 reduces the length.

The stroke length of the piston rod is short, but strip materials with different thicknesses can be processed by increasing and decreasing the piston rod length. The pressure cylinder according to the invention can therefore be used flexibly due to the adjustability of the piston rod length.

It is therefore not necessary to provide different pressure cylinders. A pressure cylinder that can meet a wide range of requirements, as described herein, is sufficient.

Increasing the piston rod length, for example, results in a distance between two rollers of a material conveying device being reduced. Reducing the piston rod length, for example, results in a distance between two rollers of a material conveying device being increased.

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%). This makes it possible, for example, to increase the length of the piston rod by 10% to 50%.

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

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 in engagement via a screw contact, in particular a thread.

The rotational movement of the first piston rod element causes a translational movement of the second piston rod element relative to the piston using a screw contact, for example a screw connection. The second piston rod element is thus driven via the thread of the screw contact. This represents a simplified and reliable movement mechanism.

A 14th embodiment of the pressure cylinder relates to one of the previous embodiments, wherein the piston is set up in such a way Translational movement of the piston to cause a corresponding translational movement of the piston rod.

When the piston performs a translational movement, the piston rod carries out a corresponding, i.e. similar and/or equal translational movement. The first and second piston rod elements also move.

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 set up to detect a current position of the piston, in particular in the cylinder space; wherein the sensor is preferably set up to detect a distance between the sensor and an underside of the piston.

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. These measurements are advantageously very precise.

A current position can in particular include the distance between the sensor and an underside of the piston. The recording can also be understood as a measurement. Advantageously, dimensions of components of the pressure cylinder are known, so that the extent to which the piston has moved can be determined using the measurement by the sensor. In this way, different thicknesses of a strip material can advantageously be determined. This can be helpful, for example, for adjusting the piston rod length when changing strip material.

In addition, the measurement can serve quality purposes, whereby an evaluation can be carried out via a control system. Furthermore, by detecting the current position, it can be determined whether intermediate ventilation has taken place. This is particularly advantageous at the high clock rates according to the invention. It can therefore be checked whether the pressure cylinder is still in the desired operation.

The measurement can also be used to determine material thickness fluctuations of a strip material when the strip material is advanced through a To detect material conveying device. The measurement results could, for example, be used to indicate any (required) further adjustment of the piston rod length (for example readjustment).

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

A pneumatic drive represents a reliable technology with which the operation, especially the intermediate ventilation, of the pressure cylinder can be carried out efficiently. As described herein, the second piston rod element may also perform translational movement due to the rotational movement of the first piston rod element. In addition to the pneumatic drive, this is possible and advantageous for adjusting the piston rod length.

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 area, which communicates essentially exclusively with the upper air connection, and preferably into a lower cylinder space area, which communicates essentially exclusively with the lower air connection.

The air connection can serve to provide a pressure in the cylinder space, which can cause the piston to move in the cylinder space. Two air connections are advantageously provided, each of which communicates with a cylinder space area. Communicating is to be understood in such a way that an exchange of air is made possible. Compressed air can thus be introduced specifically into the respective cylinder chamber area.

Two air connections offer the advantage of a double effect compared to one air connection. Therefore, no basic position of the piston and/or the piston rod is required. This can be done by adjusting the pressure.

If the pressure cylinder is operating properly, the upper cylinder space area can be understood as such that when pressure is applied to the piston and the piston rod, the contact pressure increases. If the pressure cylinder is operating properly, the lower cylinder space area can be understood as such that when pressure is applied to the piston and the piston rod, a contact pressure is reduced. For example, the upper cylinder space area can be arranged vertically above the lower cylinder space area.

An 18th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: a spacer disk which is arranged in the cylinder space; wherein the spacer disc optionally has a thickness of a maximum of 4.0 mm, preferably a maximum of 3.0 mm, further 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, further preferably at least 1.5 mm, most preferably at least 2.0 mm.

The stroke length can be adjusted individually and flexibly using the spacer. In an example, the stroke length of the piston can be reduced from 2.7 mm to 0.7 mm using a spacer with a thickness of 2.0 mm. In another example, the stroke length of the piston can be reduced from 2.5 mm to 0.5 mm using a spacer with a thickness of 2.0 mm. Increased clock speeds can thus advantageously be achieved. Compared to the prior art, in which pressure cylinders with stroke lengths of 10 mm are shown, there are therefore significant advantages.

Preferably, the spacer is arranged on an upper wall of the cylinder space, for example on an upper wall of the upper cylinder space area.

The thickness can be understood as the axial dimension of the spacer. The spacer may, in one example, have a shape that corresponds to a shape of the cylinder space. The spacer can typically be cylindrical. Usually, 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. The spacer, if it is arranged in the cylinder space, can also at least partially cover a lateral surface of the cylinder space to contact. For assembly purposes, it can be advantageous if the spacer has a smaller radius than the cylinder space.

A 19th embodiment of the pressure cylinder relates to one of the preceding embodiments, further comprising: one, preferably two, plain bearings which are designed 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, the piston rod preferably protruding at least partially beyond the lower cylinder component.

The arrangement of the upper/lower cylinder component can be understood similarly to the arrangement of the upper/lower cylinder space area. For example, the upper cylinder component can be arranged vertically above the lower cylinder component.

The airtight sealing can be understood to mean that there is essentially no pressure loss during operation of the pressure cylinder. It goes without saying that a (planned) air exchange still takes place via the air connection(s). An exchange of air between the lower and upper cylinder chamber areas is essentially prevented.

A coaxial arrangement means that the components essentially have a common axis. For example, this is a longitudinal axis. This enables a simplified structure of the pressure cylinder.

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 at least partially arranged within the cavity, wherein preferably the first piston rod element and the second piston rod element are arranged coaxially.

The cavity allows for a space-saving arrangement, which saves material and resources. In particular, there is no damage to the second piston rod element. Unless one Threaded rod is included, this can also be arranged in the cavity of the first piston rod element.

When the piston rod length is increased, the part of the second piston rod element arranged in the cavity is reduced. When the piston rod length is reduced, the part of the second piston rod element arranged in the cavity is enlarged.

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 may be 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 a maximum of 80%, preferably a maximum of 70%, further 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 a length of the second piston rod element.

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 be 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 a maximum of 95%, preferably a maximum of 90%, further 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 a length of the second piston rod element.

The inventors have succeeded in determining an optimal value of the part of the second piston rod element arranged within the cavity. This results from the fact that the possible change in the piston rod length should be large enough to be able to serve a wide range of strip material thicknesses. At the same time, sufficient stability of the piston rod should be ensured. These conflicting requirements result in the values described herein for the part of the second piston rod element enclosed by the cavity.

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

The screw contact advantageously includes an internal thread of the first piston rod element and an external thread of the second piston rod element.

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 which is designed to cause a translational movement of a roller of the material conveying device during a movement.

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

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

When the pressure cylinder is in operation, the pressure from the pressure cylinder can be transferred to a rocker. The rocker is preferably a movable rocker, which then passes on the pressure to the roller.

A 22nd embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the piston rod is set up such that the rotational movement of the first piston rod element essentially does not cause any translational movement of the first piston rod element relative to the cylinder space.

With this arrangement it can be ensured that the first piston rod element does not shift axially when it performs a rotary movement. This is expedient because otherwise the rotational movement described herein would possibly be more difficult. In addition, the rotational movement of the first piston rod element only serves to translationally move or displace the second piston rod element.

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.

Separate components offer the advantage that if one of the components wears out, only the worn component needs to be replaced. This reduces costs. In addition, the separate design enables simplified adjustment of the piston rod length.

A 24th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the translational movements run parallel to one another, the translational movements preferably running essentially at right angles to a material which is to be conveyed by the material conveying device.

The translational movements may include translational displacement/movement and/or axial displacement/movement described herein. Preferably, the translational movements are vertical, provided the pressure cylinder is operating properly.

A 25th embodiment of the pressure cylinder relates to one of the preceding embodiments, wherein the pressure cylinder is set up in such a way that the piston carries out a translational movement over the entire axial length of the cylinder space.

This offers the advantage that the pressure cylinder can be operated over the entire stroke length, for example. Preferably, the piston therefore does not carry out any movements during the stroke, with a reversal of movement being carried out in a central axial region of the cylinder space. The axial length can be as parallel to the translational direction of movement (as described herein). A separate component therefore does not necessarily have to be provided, whereby a translational movement of the piston during operation is impaired or even reduced. In this way, the pressure cylinder can advantageously always be operated in the same way, regardless of the thickness of the strip material that is to be conveyed.

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.

One 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.

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 a material conveying device. This contributes to an efficient and cost-effective material conveying device.

According to a 27th embodiment, the material conveying device of the previous embodiment further comprises a rocker and a roller; wherein the piston rod of the pressure cylinder is adapted to increase pressure on the rocker to effect 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 adapted to reduce pressure on the rocker in order to cause a translational movement of the roller away from the material that is to be conveyed by the material conveying device.

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

During operation of the pressure cylinder, intermediate ventilation can take place (in this embodiment this is seen as an increase/decrease in pressure understand). The intermediate ventilation 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 set up in such a way that when the pressure on the rocker is reduced (for example when the pressure on a surface of the piston is reversed, i.e. when the piston moves upwards), the rocker is moved upwards. Increasing 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 carried out pneumatically by means of the piston.

The direction of movement towards the material can, in one example, be understood as directed vertically downwards. The direction of movement away from the material can, in one example, be understood as being directed vertically upwards.

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 creates a distance, preferably an axial distance, of the piston rod and / or the roller to a material that is to be conveyed by the material conveying device , changed, wherein preferably the rotational movement in a first direction reduces the distance, and the rotational movement in a second direction increases the distance.

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

A 29th embodiment relates to the material conveying device according to one of the previous 26th to 28th embodiments, wherein the pressure increase and/or the pressure reduction takes place pneumatically; whereby the rotational movement is not pneumatic.

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 member of a piston rod of the pressure cylinder in a first direction to cause a translational movement of a second piston rod element of the piston rod of the pressure cylinder; terminating 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, preferably when contact has been achieved, the first piston rod member in a second direction to effect opposite translational movement of the second piston rod member.

The depressurization can serve to enable the piston to be moved in one direction, for example upwards, preferably completely upwards. The piston has thus reached an upper end of the cylinder chamber. This makes it easier to adjust the length of the piston rod, for example for thick strip material.

Turning in the first direction can also be stopped if 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).

In particular, if a motor is included, the method can be automated. Turning in the first direction is advantageously done with the help of the motor. The rotation in the first direction can be carried out automatically until contact between the roller and the strip material is achieved. This contact can be determined, for example, by an increased current consumption of the motor. It is also possible to determine the contact using a sensor, which is preferably arranged in the cylinder space. This sensor can be an eddy current sensor.

You can then rotate in the second direction. This turning in the second direction should preferably only occur to the extent that the strip material is released. A distance between should be advantageous The roller and strip material must be so small that sufficient pressure can be built up between the roller and strip material during a translational movement of the piston over the stroke length (when the pressure cylinder is in operation). This pressure should be sufficient to provide enough traction to advance the strip material. The pressure can vary depending on the belt material and can be adjusted using a pressure regulator. A pressure in the range from 1.5 bar to 8 bar, preferably in the range from 2 bar to 6 bar, is conceivable.

Preferably, the piston is pressurized so that the material conveying device is set up ready for operation to convey strip material.

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

This offers the advantage that the piston rod can be adjusted to a reduced length, preferably to the smallest length. Consequently, this provides the ability to convey large thickness strip material.

4. Brief description of the characters

Fig. 1

zeigt einen Anpresszylinder in einer Materialfördervorrichtung gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 2

zeigt einen Anpresszylinder gemäß einem ersten Aspekt der vorliegenden Erfindung in einer Perspektivansicht;

Fig. 2a

zeigt den Anpresszylinder gemäß Fig. 2 in einer seitlichen Querschnittsansicht;

Fig. 2b

zeigt den Anpresszylinder gemäß Fig. 2a, wobei die Kolbenstange verlängert ist;

Fig. 2c

zeigt den Anpresszylinder ähnlich gemäß Fig. 2a, wobei der Kolben translatorisch nach unten bewegt ist (die Länge der Kolbenstange ist gegenüber Fig. 2a auf ein Minimum verkleinert);

Fig. 3

zeigt einen Anpresszylinder gemäß einem zweiten Aspekt der vorliegenden Erfindung in einer Perspektivansicht;

Fig. 3a

zeigt den Anpresszylinder gemäß Fig. 3 in einer weiteren Perspektivansicht;

Fig. 3b

zeigt den Anpresszylinder gemäß Fig. 3 in einer seitlichen Querschnittsansicht;

Fig. 3c

zeigt den Anpresszylinder gemäß Fig. 3b, wobei die Kolbenstange verlängert ist;

Fig. 3d

zeigt den Anpresszylinder gemäß Fig. 3b, wobei der Kolben translatorisch nach unten bewegt ist;

Fig. 4

zeigt einen Anpresszylinder gemäß einer Ausführungsform der vorliegenden Erfindung;

Fig. 5

zeigt einen Anpresszylinder gemäß einer weiteren Ausführungsform der vorliegenden Erfindung; und

Fig. 6

zeigt ein schematisches Ablaufdiagramm eines Verfahrens zur Verstellung einer Kolbenstangenlänge gemäß einer Ausführungsform der vorliegenden Erfindung.

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 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. 2 in 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 in a similar way 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 , where the piston rod is extended;

Fig. 3d

shows the pressure cylinder according to Fig. 3b , with the piston 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

A rotary movement , rotation and rotation can be understood as synonymous here.

A stroke length can also be understood as a path length, in particular as a total path length, that the piston performs in the cylinder space during operation of the pressure cylinder. This can also be viewed as a piston stroke . For example, this can be an axial length between the piston and the wall of the Be cylinder space. In some cases, as preferred herein, the stroke length may correspond to a total axial length of the cylinder space (minus a portion occupied by the piston).

The pressure cylinder of the present invention can also be viewed as an intermediate ventilation cylinder. The pressure cylinder should in no way be understood as limiting in the sense that the pressure cylinder inevitably causes pressing. However, the pressure cylinder should be suitable for a material conveying device and therefore differs, for example, from cylinders that are usually used in the operation of motor vehicles and/or piston engines.

Character description

Only a few possible embodiments of the invention are described in detail below. 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 if they appear unnecessary. In particular, the disclosed embodiments may be modified by combining certain features of one embodiment with one or more features of another embodiment.

Throughout the present figures and description, the same reference numerals refer to the same elements. It is understood that the reference numbers (100-199) of the figures of the first aspect also apply to the figures of the second aspect (with reference numbers 200-299) and are not listed separately for the sake of clarity. 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.

Fig. 1 shows a pressure cylinder 100, 200 (henceforth the reference number 200 is not 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.

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 with a reference number) in the conveying direction F.

The pressure cylinder 100 includes a piston rod 110, which is designed to come into engagement with a movable component 2 of the material conveying device 1. Furthermore, the pressure cylinder 100 includes a cylinder space 120, which is designed to at least partially guide the piston rod 110. This means, for example, that the piston rod 110 extends through the cylinder space 120. Furthermore, a piston 130 is included, which is movably arranged in the cylinder space 120 and which is in connection with the piston rod 110 (for example at least partially through a positive connection).

The piston rod 110 includes a first piston rod element 111 and a second piston rod element 112, which are set up 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.

The piston rod 110 of the pressure cylinder 100 is designed to increase pressure on the rocker 2 in order to cause 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 2 can rotate via the pivot point 3. The piston rod 110 of the pressure cylinder 100 is also designed to reduce pressure on the rocker 2 in order to cause 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 pressure is increased or reduced by means of a pneumatic operation of the drive cylinder 100 and can take place during intermediate ventilation, for example with at least 1500 stroke/min or at least 2000 stroke/min or at least 2500 stroke/min.

In this exemplary arrangement, the direction towards the material 10 can be understood as directed vertically downwards. The direction away from the material 10 can be understood as directed vertically upwards.

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.

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

The pressure cylinder 100 includes 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 space (not shown) in a substantially airtight manner.

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 space (or into an upper and a lower cylinder space area) (pressure build-up) or let out (pressure reduction).

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

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

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 marked separately).

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

The pressure cylinder 100 includes two plain bearings 150, which are designed to accommodate the piston rod 110. In particular, the first piston rod element 111 is received by the two plain bearings 150.

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

A washer 172 is arranged between the lock 170 and the piston rod 110 (represented by 111 and 112). The threaded rod 160 protrudes through the washer 172. The threaded rod 160 is thus 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 thread levels 160 and then lock the rotational position of the handwheel 180. For example, a set length of the piston rod 110 can advantageously not change during operation of the pressure cylinder 100.

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

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

Fig. 2b shows the pressure cylinder 100 according to Fig. 2a , whereby the piston rod 110 is extended. For reasons of clarity, not all reference symbols in the previous figure are shown. The corresponding reference numbers in the preceding figures apply to components that are not explicitly marked.

This figure shows an arrangement in which the length Lo of the piston rod 110 is extended. A comparison with the previous figure makes it clear that the second piston rod element 112 is displaced translationally (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 reduces the length Lo. The first and second directions are opposite. The rotational 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 in engagement 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.

A handwheel 180 is shown which, during a rotary movement, exerts a correspondingly rectified rotary movement on the first piston rod element 111. This makes it easier to adjust the length of the piston rod 110, since it has a larger radius than the first piston rod element 111 and therefore requires less effort 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.

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.

When the length Lo of the piston rod 110 is set to a minimum length (similar to in Fig. 2c ), the part arranged 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 maximum 90%, for example 63% of the length L1 (the marking is in Fig. 2c visible) of the second piston rod element 112.

When the length Lo of the piston rod 110 is set to a maximum length Lo (similar to in Fig. 2b ), the part arranged 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.

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 in the range of 110% to 150%. In this example, the result is a value of 120%, so that the piston rod 110 can advantageously be extended by 20% of its shortest length. Expressed in absolute values, the maximum length Lo can be 115 mm and the minimum length Lo can be 95 mm.

Fig. 2c shows the pressure cylinder 100 according to Fig. 2a , with the piston 130 moved downward. 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).

During (pneumatic) operation of the pressure cylinder 100, the air connections serve to provide a pressure in the cylinder space 120, which causes the piston 130 to move in the cylinder space 120. The position of the piston 130 is shown at a lower end of the cylinder space 120. In this figure, the lower cylinder space region 147 is therefore not shown and the cylinder space 120 not filled by the piston 130 is essentially defined by the upper cylinder space region 142.

During (pneumatic) operation of the pressure cylinder 100, the handwheel 180 is moved translationally together with the piston rod 110 and the piston 130 (eg during intermediate ventilation). 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. 2c indicates the arrangement of the handwheel 180 in the two different positions of the piston 130 of the pressure cylinder 100.

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

Advantageously, there is a small axial length of the cylinder space 120 (or visible here through the upper cylinder space region 142), so that the stroke length L3 is made small. Consequently, an increased clock speed can be achieved.

The piston 130 advantageously carries out a translational movement over the entire axial length L3 of the cylinder space 120 (except for the axial length of the cylinder space 120, which is occupied by the piston 130). The entire axial length is shown using the stroke length L3.

Fig. 3 shows a pressure cylinder 200, 100 (hereinafter referred to as 200) according to a second aspect of the present invention in a perspective view. The person skilled in the art will understand that the same reference numbers designate the same components of the first aspect. For example, 112 stands for the second piston rod element 112. The same components of the first aspect can therefore also be used for the second aspect. Advantageously, in the second aspect, a threaded rod, a handwheel and/or a separate lock are not absolutely necessary. In the second aspect, the first piston rod element 111 can advantageously be set up to be rotatable relative to the piston 130 (or the piston 130 is rotatable to the first piston rod element 111).

The second piston rod element 112 includes a fixing component, which can be a cross pin, whereby rotation of the second piston rod element 112 when the first piston rod element 111 rotates can be essentially prevented. The fixing component projects laterally at least partially beyond a side surface of the piston rod. The fixing component can be in engagement 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 in addition, an installation position of the second piston rod element 112 in a movable component 2 of the material conveying device 1 can essentially prevent rotation of the second piston rod element 112 when the first piston rod element 111 rotates.

The pressure cylinder further comprises a motor 280, which is designed to cause the rotational movement of the first piston rod element 111.

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

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.

Fig. 3b shows the pressure cylinder 200 according to Fig. 3 in a side cross-sectional view. This figure shows the components, the names of which will be clear to the person skilled in the art, among other things Fig. 2-2c and are not listed again for reasons of clarity.

The motor 280 further comprises a clutch 281, which is essentially fixedly connected to a motor shaft 282 of the motor 280, the clutch 281 being in engagement with the first piston rod element 111. The piston rod 110, in particular the first piston rod element 111, is set up to be axially movable relative to the coupling 281. The piston rod 110, in particular the first piston rod element 111, is not designed to be rotatable relative to the clutch 281. The two components are therefore essentially connected in a rotationally fixed manner (via the square connection described here). The coupling 281 can thus 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 (unintentional) change in a set length Lo of the piston rod 110 can be substantially prevented.

Fig. 3c shows the pressure cylinder 200 according to Fig. 3b , whereby the piston rod 110 is extended. To understand the reference numbers in this figure, the corresponding description points apply 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 with the help of changing the length Lo of the piston rod 110 between Fig. 2b and Fig. 2c (and between Fig. 2b and Fig. 2a ).

It is advantageous to refer to Fig. 3b and Fig. 3c However, the rotational movement of the first piston rod element 111 is caused by the motor 280.

When the length Lo 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 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.

If 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% the length L1 of the second piston rod element 112.

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 of 110% to 150%. In this example, the result is a value of 120%, so that the piston rod 110 can advantageously be extended by 20% of its shortest length.

Fig. 3d shows the pressure cylinder 200 according to Fig. 3b , with the piston moved downwards. The length Lo of the piston rod 110 is as in Fig. 3b reduced to a minimum. The ratio of the length L2 to L1 is therefore the largest.

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

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

The pressure cylinder 100, 200 includes a spacer 121 which is arranged in the cylinder space 120. The spacer 121 has a thickness of a maximum 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 spacer 121). The stroke length L3 can thus be advantageously reduced. This enables higher clock speeds. For example, the stroke length L3 of 0.7 mm can also mean an intermediate ventilation opening of 0.7 mm, which the pressure cylinder 100, 200 provides.

The spacer 121 is arranged on an upper wall of the upper cylinder space region 141 (not separately marked), this wall coinciding with a lower wall of the upper cylinder component 140.

The (axial) end positions of the piston 130 in the cylinder space 120 are provided via 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.

For example, the pressure cylinder 100, 200 can enable at least 1500 strokes/min or at least 2000 strokes/min. This advantageously provides high clock speeds. In an example, it could also be relevant how much time is available to execute the hub. This can be influenced by an intermediate ventilation angle and/or a required (air) pressure:
The intermediate lift angle can affect the time available to perform an intermediate lift stroke (i.e. moving the piston up and moving the piston down). For example, an intermediate ventilation angle of 60° (assuming 500 stroke/min, which means 0.12 seconds/stroke) means that only 360°/60° = 1/6 of the time is available to carry out intermediate ventilation (0.12 seconds/stroke /6 = 0.02 seconds/stroke). Consequently, in one example, higher cycle rates (higher stroke/min) can be carried out at higher intermediate ventilation angles (da more time is available). The example is for comprehension purposes only and is not intended to be limiting.

The influence of pressure can be understood as follows: the less air pressure is required, the faster the cylinder space can be filled. If the required air pressure is higher, more air volume must be introduced into the cylinder chamber because, under simplifying assumptions, the air can be compressed in accordance with the ideal gas law.

Fig. 5 shows the pressure cylinder 100, 200 according to a further embodiment of the present invention.

The pressure cylinder 100, 200 includes a sensor 155, preferably an eddy current sensor 155, which is set up to detect a current position of the piston 130 in the cylinder space 120. The sensor 155 is set up to detect a distance between the sensor 155 and an underside of the piston 130.

The principle of a measurement using an eddy current sensor 155 can be understood as follows: If 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. Dimensions, distances and/or positions, in particular of electrically conductive components, can thus be determined.

Fig. 6 shows 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 includes: 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 cause a translational movement of a second piston rod element 112 of the piston rod 110 of the pressure cylinder 100, 200; Termination of rotation 1500 when there is 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 effect opposite translational movement of the second piston rod member 112.

In the above embodiments, 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.

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

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

1

Material conveying device, especially roller feed

2

Seesaw

3

Pivot point of the rocker

5.6

roller

10

Band material

F

Conveying direction of the strip material

Lo

Length of the piston rod

L1

Length of the second piston rod element

L2

Part of the second piston rod element, which 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 space

121

spacer

130

Pistons

140

Upper cylinder component

141

Top air connection

142

Upper cylinder chamber area

145

Lower cylinder component

146

Lower air connection

147

Lower cylinder chamber area

150

bearings

155

sensor

160

Threaded rod

161

upper thread of the threaded rod

162

lower thread of the threaded rod

170

Locking

171

Knurled nut

180

Handwheel

280

engine

281

coupling

282

Motor shaft

1000

Proceedings

1100

Process step: optional depressurization

1200

Process step: optionally turning in a second direction

1300

Process step: introducing material

1400

Process step: Rotate in a first direction

1500

Process step: Stop turning

1600

Process step: optionally turning in a second direction

Claims (15)

Pressure cylinder (100, 200) for a material conveying device (1), in particular for a roller feed, comprising: a piston rod (110) adapted to come into engagement with a movable component (2, 5) of the material conveying device (1); a cylinder chamber (120) which is designed to at least partially guide the piston rod (110); a piston (130) which is arranged in the cylinder space (120) and which is in connection with the piston rod (110); and a motor (280); wherein the piston rod (110) comprises a first piston rod element (111) and a second piston rod element (112), which are set up 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 motor (280) is designed to cause the rotational movement of the first piston rod element (111). The pressure cylinder (100, 200) according to the preceding claim, wherein the first piston rod element (111) is rotatable relative to the piston (130). The pressure cylinder (100, 200) according to one of the preceding claims, wherein the motor (280) is arranged not to cause any translational movement of the first piston rod element (111). The pressure cylinder (100, 200) according to one of the preceding claims, further comprising:
a clutch (281) substantially fixedly connected to a motor shaft (281) of the motor (280), the clutch (281) engaging the first piston rod member (111); wherein the piston rod (110), in particular the first piston rod element, is designed to be axially movable relative to the coupling (281); wherein preferably the piston rod (110), in particular the first piston rod element, is not rotatable relative to the coupling (281). The pressure cylinder (100, 200) according to one of the preceding claims, wherein the piston rod (110) is designed 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 , 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 (110) is designed 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. 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 reduces the length (Lo). 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 in engagement via a screw contact (115), in particular a thread. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the piston (130) is set up to cause a corresponding translational movement of the piston rod (110) when the piston (130) moves in translation. The pressure cylinder (100, 200) according to one of the preceding claims, further comprising: a sensor (155), preferably an eddy current sensor, which is set up to detect a current position of the piston (130), in particular in the cylinder space (120); wherein the sensor (155) is preferably set up to detect a distance between the sensor (155) and an underside of the piston (130). 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) occur exclusively pneumatically. The pressure cylinder (100, 200) according to one of the preceding claims, further comprising: a spacer (121) arranged in the cylinder space (120); wherein the spacer (121) optionally has a maximum thickness of 4.0 mm, preferably has a maximum of 3.0 mm, further preferably a maximum of 2.5 mm, most preferably a maximum of 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. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the first piston rod element (111) has a cavity (113), the second piston rod element (112) being at least partially arranged within the cavity (113),
wherein preferably the first piston rod element (111) and the second piston rod element (112) are arranged coaxially. The pressure cylinder (100, 200) according to one of the preceding claims, wherein the pressure cylinder (100, 200) is set up such that the piston (130) carries out a translational movement over the entire axial length of the cylinder space (120). Material conveying device (1), in particular roller feed, comprising a pressure cylinder (100, 200) according to one of the preceding claims. 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 13, comprising: optional depressurization (1100) of 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 in order to cause 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 is reached between a movable component (2, 5) of the material conveying device (1) and the material (10); optionally rotating (1600), preferably when contact has been achieved, the first piston rod member (111) in a second direction to effect opposite translational movement of the second piston rod member (112).

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