EP2942304A1 - Label dispenser with a motorised coiling device - Google Patents

Abstract

The invention relates to a label dispenser (1) with a winding device (4) which comprises a dancer arm (6) and a take-up reel (5), wherein a sensor (17) is provided for detecting the position of the dancer arm (6). A controller (20) controls a motor drive (18) for the take-up reel (5) as a function of the position of the dancer arm (6) so that it is largely in a predetermined position to produce a continuous web tension of the label carrier tape (8) ,

Description

The invention relates to a label dispenser with a motor winding device according to the preamble of claim 1 or to a method with the features of claim 9.

It is from the WO 2007/124821 A1 a label dispenser is known which comprises a driven receptacle for the label carrier material. In this case, the web tension of the label carrier material is determined before winding by means of a sensor to drive the recording such that a predetermined web tension is present at the receptacle to flutter or hitting the label carrier material during transport within the label dispenser by a partially too low web tension prevent. The web tension measuring sensor detects a linear path, which is caused by the existing web tension on a roll on the sensor. Such a detection of the web tension is less sensitive and easily influenced by existing disturbances such as breakaway torque when starting the label dispenser and changing the diameter of the wound label carrier material negative.

It is still out of the EP 2 479 114 A1 a label dispenser with a drivable mandrel and a previously arranged deflection known. On the position of an adjustable role of the deflection, the tightness or belt tension of wound on the winding mandrel label carrier bands can be adjusted, as a function of the position of this role, the speed of the winding mandrel is adjustable. The disadvantage of this is the need to adjust the role.

From the DE 41 42 158 A1 Another labeling machine is known.

Object of the present invention is to improve a label dispenser to the effect that an improved and structurally simpler design for a constant web tension of a label carrier tape is achieved during winding.

This object is achieved by a label dispenser with the features of claim 1 or by a method for operating a label dispenser with the features of claim 9. Advantageous developments of the invention are specified in the dependent claims.

The label dispenser according to the invention comprises a controller, an unwinding device, a dispensing unit and a reeling device, wherein the reeling device has a motor drive for a take-up reel and a dancer arm with a deflection roller. The label dispenser is characterized in that a sensor for detecting an actual angle or a position of the dancer arm is provided, wherein the controller is configured to the motor drive in dependence of the actual angle of the dancer arm and a present in the control target To regulate angles. Thus, the position of the dancer arm can be maintained very accurately and a very constant web tension can be achieved, regardless of various disturbances such as changing the diameter of the wound label carrier tape or different transport speeds of the label carrier tape. For this regulation, only a single sensor for detecting the position or the angle of the dancer arm is necessary, which greatly simplifies the construction.

The motor drive preferably has a servomotor or a stepper motor in order to achieve a particularly sensitive control with a high resolution.

In a particularly advantageous embodiment, the sensor is a rotary encoder or a magnetic angle sensor. A magnetic angle sensor has the additional advantage that it can detect without contact a ring magnet mounted on the axis of rotation of the dancer arm and such angle sensors have a high resolution or repeatability of 0.1 °.

Preferably, the dancer arm can be prestressed by means of at least one tension spring in a transport direction of the label carrier tape by means of the deflection roller of the dancer arm. On the position of the dancer arm and thus on the deflection of the tension spring and the tensile force generated therewith, the bias voltage or the web tension on the label carrier tape is adjustable and always constant in this position.

Preferably, a motor-driven feed unit for the label carrier tape is provided between the dispensing unit and the take-up device, which determines the labeling speed and thus the transport speed of the label carrier tape. The feed unit is in a continuous and / or intermittent Mode operable to be prepared for all necessary labeling tasks and labeling services.

A method according to the invention for operating a label dispenser comprising a controller, an unwinding device, a dispensing unit and a reeling device, wherein the reeling device has a motor drive and a dancer arm with a deflection roller, is characterized in that a sensor has an actual angle of the dancer arm detected and the controller calculates an angular deviation by means of an existing in the control target angle, the controller controls the motor drive in dependence of the angular deviation of the dancer arm. Thus, the dancer arm can be kept as far as possible in the position in which an optimal and constant web tension of the label carrier tape is present. This control is independent of different and constantly changing disturbances such as changing the diameter of the wound label carrier tape or different transport speeds of the label carrier tape.

In a particularly advantageous embodiment, the controller controls the motor drive permanently during operation of the label dispenser, the motor drive thereby permanently rotates the take-up reel in the winding and wound up the label carrier tape. Due to the permanent control and thus a continuous winding stop can be avoided. Thus, high start-up accelerations and breakaway torques can be avoided, which can lead to increased web tensions and can cause tearing of sensitive label media, resulting in increased machine downtime.

Preferably, with an increasing angular deviation in the transport direction of the label carrier tape from the setpoint angle, the motor drive is accelerated more strongly and / or the speed is increased in order to bring the dancer arm as quickly as possible back into the predetermined position. In this case, the acceleration can be limited so that excessive web tension can be avoided.

Preferably, with an increasing angular deviation against the transport direction of the label carrier tape, the motor drive is less accelerated by the setpoint angle and / or the speed is reduced in order to move the dancer arm as fast as possible to bring back to the predetermined position. Low accelerations allow a smooth movement without major changes in the web tension.

In the invention, the last deflection of the label carrier tape can be done before reaching the take-up reel on the deflection roller of the dancer arm. It is conceivable that the wrap angle of the label carrier tape on the deflection roller of the carrier arm is from 90 ° to 180 °. Consequently, this also includes a variant in which the direction of movement of the label carrier exactly reverses on the deflection roller of the carrier arm. Due to the comparatively large wrap angle of the label carrier tape on the deflection roller of the dancer arm, the influence of the change in the diameter of the wound label carrier tape is minimized as far as possible.

Fig. 1

eine perspektivische Ansicht eines erfindungsgemäßen Etikettenspenders von vorne,

Fig. 2

eine Frontansicht des Etikettenspenders mit Darstellung des Etikettenträgerbandverlaufs,

Fig. 3

eine perspektivische Ansicht der Aufwickelvorrichtung ohne Abdeckung von hinten und

Fig. 4

eine vergrößerte Rückansicht der Aufwickelvorrichtung ohne Darstellung von Antrieb und Sensor.

In the following, an advantageous embodiment of the invention is explained in detail with reference to a drawing. In detail show:

Fig. 1

a perspective view of a label dispenser according to the invention from the front,

Fig. 2

a front view of the label dispenser showing the label carrier strip course,

Fig. 3

a perspective view of the winder without cover from the back and

Fig. 4

an enlarged rear view of the winder without representation of drive and sensor.

The same components are provided throughout the figures with the same reference numerals.

Fig. 1 shows a front view of a label dispenser 1 according to the invention with an unwinding device 2, a dispensing unit 3 and a winding device 4. The reeling device 4 comprises a take-up reel 5 and a dancer arm 6 with a deflection roller 7.

In Fig. 2 the scheme of the course of the label carrier tape 8 on the label dispenser 1 is shown. The label carrier tape 8 with labels 9 is from the unwinding device. 2 deducted and thereby deflected by two stationary deflection rollers 10 and a prestressed dancer arm 11 with a deflection roller 12 of the unwinding device 2, thereby having a web tension. The responsible for the removal drive is a motor-driven feed unit 13 with a drive roller 14 and a pinch roller 15. The feed unit 13 is arranged after the dispensing unit 3, the labels 9 at a dispensing edge 16 from the label carrier tape 8 to be labeled, not shown in detail, Product dispenses. The label carrier tape 8 without labels 9 is pressed by the pinch roller 15 to the drive roller 14 to ensure the feed or transport of the label carrier tape 8. Depending on the power or dispensing cycle, the feed unit 13 is operated continuously or intermittently. The term "continuous" not only includes a constant speed, but also different accelerations with different speeds with permanent drive. "Intermittent" means that between the dispensing of individual labels 9 or a group of multiple labels 9, the feed unit 13 stops until the next label 9 is to be dispensed.

In the further course after the feed unit 13, the label carrier tape 8 is fed to the take-up device 4 in a transport direction T and deflected around the deflection roller 7 of the dancer arm 6 of the take-up device 4, before being wound up on the take-up reel 5. The dancer arm 6 is pretensioned and causes a web tension. The desired and optimal web tension for different label carrier belts 8 is ß by a target angular _SOLL of the dancer arm 6 about its rotational axis D, see Fig. 4 , given.

In Fig. 2 are shown with dashed lines two deflected in both directions positions of the dancer arm 6, which have a respective actual angle ß _IST . About one in Fig. 3 controller 20 is above the setpoint angle ß _target and the actual angle ß _IST an angular deviation .DELTA.ß (hereinafter: dß) is calculated, which is the input variable for the control of a motor drive 18 of the take-up reel 5 as a control deviation. Under the influence of the motor drive 18, the take-up reel 5 rotates in a winding direction W. In the view according to FIG FIG. 2 this rotation is counterclockwise.

At the deflection roller 7 of the dancer arm 6, the last deflection of the label carrier tape 8 takes place before reaching the take-up reel 5. The transport direction of the label carrier tape 8 between the deflection roller 7 and the take-up reel 5 is identical to the tangential direction of the wound already on the take-up reel 5 label carrier tape 8 at the point at which the label carrier tape 8 reaches the take-up reel 5 for the first time. The angle between the transport direction 5 of the label carrier tape 8 in front of the deflection roller 7 on the dancer arm 6 and the transport direction T of the label carrier tape 8 beyond the deflection roller 7 is identical to the wrap angle of the label carrier tape 8 on the deflection roller 7. In the situation in FIG. 2 this angle is about 147 °. It varies as a function of the respective actual angle β _{actual of} the dancer arm 6. Overall, the wrap angle may preferably be between 90 ° and 180 °, so that a complete reversal of direction of the label carrier tape 8 is possible. A large angle of wrap on the deflection roller 7 minimizes the influence of the change in the diameter of the already grown on the take-up reel 5 label carrier tape 8 on the tensile stress in the growing diameter.

In FIG. 2 It can be seen that the axis of rotation D, about which the dancer arm 6 pivots, is parallel both to an axial direction of the take-up reel 5 and to the axial direction of the guide roller 7. Regardless of the illustrated embodiment, this relationship may be present in any embodiments of the invention.

Fig. 3 shows in a rear view of the winding device 4, a sensor 17, which detects the actual angle ß _IST the dancer arm 6 about its axis of rotation D. The take-up reel 5 is driven by a motor 18, preferably a servomotor. The controller 20 is provided in a housing 19 of the label dispenser 1. A control unit, not shown, may be integrated in the housing 19 or via an externally provided operator terminal inputs can be made by an operator.

Fig. 4 shows a rear view of the winding device 4 without the motor 18 and the sensor 17. The dancer arm 6 is deflected about its axis of rotation D and is two tension springs 21 by means of two levers 22 on an axis 23 of the dancer arm 6 in the transport direction T of the label carrier tape 8, see Arrow on dancer arm, pretensioned. About the position of the dancer arm 6 and thus on the tensile force of the tension springs 21, the web tension of the label carrier tape 8 can be determined and adjusted. On the axis 23, a ring magnet 27 is arranged on the end remote from the dancer arm 6 end. The magnetic field generated by the ring magnet 27 is detected by the sensor 17 in the form of a magnetic angle sensor without contact and the sensor 17 determines the position and change of the magnetic field is the position and the actual angle β _{IS of} the dancer arm 6. The sensor 17 converts the information into an electrical voltage between 0 and 10 V. The controller 20 is connected to the sensor 17 and converts the applied voltage into an angle value β _IST . The motor 18 drives a first pulley 24. By means of a belt 25, preferably a toothed belt, the rotation is transmitted with a gear ratio of at least 4: 1 to a second pulley 26, wherein the second pulley 26 is connected to the take-up reel 5.

The axis of rotation A of the second pulley 26 in this embodiment is identical to the axis of rotation A of the take-up reel 5, ie with the axial direction of the take-up reel 5. In FIG. 4 It can be seen that the axis of rotation D of the dancer arm 6 is aligned parallel to the axis of rotation A of the second pulley 26 and the take-up reel 5, but there is an offset between the two axes of rotation D, A. In an alternative embodiment, it is conceivable that the two axes of rotation D, A coincide, ie that there is no lateral offset between the two axes of rotation D, A.

The regulation will be explained in more detail below. When starting the label dispenser 1 and starting donating labels 9, the feed unit 13 transports the label carrier tape 8 in the direction of the take-up device 4. The motor 18 starts at the same time to rotate the take-up reel 5 and wind the label carrier tape 8. The dancer arm 6 is deflected and the controller 20 recognizes via the sensor 17 that there is an angular deviation dβ compared with the parameter for the desired angle β _SOLL stored in the controller 20. Depending on the direction of the deflection in or against the transport direction T, the motor 18 is accelerated or braked or adapted to the speed. Depending on the rate of change of the angular deviation d itself, the controller 20 also increases or decreases the acceleration of the motor driver 18 while changing the rotational speed of the take-up reel 5. Consequently, there are two manipulated variables in this embodiment. The amount of angular deviation dβ influenced by the controller 20, the set speed of the motor 18 and thus the take-up reel 5. The derivative of the change in the angular deviation dß over time, ie the rate of change of the angular deviation, represents a second control variable, which is measured separately and the amount of acceleration of the motor 18 between two speed values is influenced by the controller 20. The faster the angular deviation dß changes, the higher the acceleration is chosen at which the motor 18 is brought from a first speed to a second speed, and vice versa. However, in a simpler embodiment, only the angular deviation δs itself is measured as the only manipulated variable, but not the rate of change of the angular deviation.

There are also alternative designs conceivable. As sensor 17 is also an incremental or absolute rotary encoder can be used. The motor 18 may also be arranged directly on the take-up reel 5 without a belt drive.

The label dispenser according to the invention is particularly well suited for the labeling of packages, in particular made of plastic, as they are produced in packaging machines, for example in tray sealing machines or thermoforming packaging machines.

Claims (13)

A label dispenser (1), comprising a controller (20), an unwrapping device (2) for a label carrier tape (8), a dispensing unit (3) and a take-up device (4) for the label carrier tape (8), wherein the take-up device (4) comprises a motor Drive (18) for a take-up reel (5) characterized in that the take-up device (4) has a dancer arm (6) with a deflection roller (7), and that a sensor (17) for detecting an actual angle (ß _IST ) of the Dancer arm (6) is provided, wherein the controller (20) is configured to the motor drive (18) of the winding device (4) in dependence of the actual angle (ß _IST ) of the dancer arm (6) and one in the controller (20 ) existing target angle (ß _SOLL ) to regulate. Label dispenser according to claim 1, characterized in that the motor drive (18) has a servo motor or a stepping motor. Label dispenser according to one of the preceding claims, characterized in that the sensor (17) is a rotary encoder or a magnetic angle sensor. Label dispenser according to one of the preceding claims, characterized in that the dancer arm (6) can be prestressed by means of at least one tension spring (21). Label dispenser according to one of the preceding claims, characterized in that a motor-driven feed unit (13) for the label carrier tape (8) is provided between the dispensing unit (3) and the take-up device (4). Label dispenser according to claim 5, characterized in that the feed unit (13) is operable in a continuous and / or in an intermittent mode. Label dispenser according to one of the preceding claims, characterized in that the deflection roller (7), an axial direction of the take-up reel (5) and / or a rotation axis (D) of the dancer arm (6) are parallel to each other. Label dispenser according to one of the preceding claims, characterized in that the wrap angle of the label carrier tape (8) on the deflection roller (7) of the dancer arm (6) is 90 ° to 180 °. A method for operating a label dispenser (1) comprising a controller (20), an unwrapping device (2) for a label carrier tape (8), a dispensing unit (3) and a take-up device (4) for the label carrier tape (8), wherein the reeling device (4) has a motor drive (18), characterized in that the winding device (4) has a dancer arm (6) with a deflection roller (7) that a sensor (17) an actual angle (ß _IST ) of the dancer arm ( 6) and the controller (20) calculates an angular deviation (dβ) by means of a desired angle (β _desired ) present in the controller (20), the controller (20) controlling the motor drive (18) of the take-up device (4) in FIG Dependence of the angle deviation (Δß) of the dancer arm (6) regulates. A method according to claim 9, characterized in that during operation of the label dispenser (1), the controller (20) permanently controls the motor drive (18), wherein the motor drive (18) permanently the take-up reel (5) in the winding direction (4). rotates. A method according to claim 9 or 10, characterized in that at an increasing angular deviation (.DELTA.ß) in the transport direction (T) of the label carrier strip (8) from the desired angle (ß _SOLL ), the speed of the motor drive (18) is increased. Method according to one of claims 9 to 11, characterized in that at an increasing angular deviation (.DELTA.ß) against the transport direction (T) of the label carrier strip (8) of the desired angle (ß _SOLL ), the speed of the motor drive (18) is reduced. Method according to one of claims 9 to 12, characterized in that the label carrier tape (8) on the deflection roller (7) of the dancer arm (6) is deflected by 90 ° to 180 °.

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