EP1409351B1 - Method for the application of self-adhesive labels - Google Patents

Description

The invention relates to a method for applying self-adhesive labels on flat objects transported along a conveying path by means of a controlled driven pressure and applicator drum.

In the processing of flat mail, in particular letters, postcards, etc., by mail carriers, the task of securely and quickly applying labels to flat mailings occurs. An example of this is automatic forwarding of broadcasts. In this case, programs are sorted out for forwarding and addressed according to predetermined data stored in a database. These shipments are covered with a label covering both the old address and any bar code possibly applied to the mailing surface. Subsequently, the label is provided with a new barcode and the corresponding new address. The application of the label takes place in devices that are integrated in automatic letter distribution. The shipment volume for such distribution systems varies in format, weight and thickness. The shipments are sent in such facilities as e.g. with speeds of 3.6 m / sec, which places high demands on the speed with which the labels must be applied and on the exact positioning of the labels. Moreover, a general problem is the handling and in particular the transport of the labels to the mailing surface if the labels have a self-adhesive surface.

From US-A-5 200 007 a device for applying labels to flat mail items, which are occasionally transported on an edge with a conveying device along a conveying path, is described. She owns one A label conveying device for conveying the labels located on a substrate, which is controlled by a sensor device for determining the mailing leading edge, and a pressure or applicator device for applying / pressing the labels onto the mailing surface. In this device, the labels are printed with distribution information. Labeling at high transport speeds of the shipments is not possible hereby.

Also known was a labeling device in which mailing labels are applied to mail items by means of a round applicator drum which has openings with a controllable negative pressure for temporarily holding the labels in its surface. The supply and the cutting of the label webs takes place so that labels without addresses are not applied (US 4 421 587).

DE 36 22 502 A1 describes a labeling head machine in which the labels on the labeling head, which presses the labels onto the object, are held by means of openings in the head surface, which are connected to a vacuum source.

If the label can be pushed onto it only when the pressure and applicator drum is at rest, the drum must be accelerated from a standstill to a peripheral speed corresponding to the transport speed of the flat objects during each application process, at which point the label touches the one on the pressure applicator drum is transported past transported object. Subsequently, the pressure roller and applicator drum is braked so that it comes to a stop again in the starting position after one revolution.

Due to various influences, eg belt elongation of a shroud system for the transport of letters, changes constantly the transport speed with which letters are conveyed past the pressure and applicator drum.

However, if the respective label is always placed precisely at a predetermined position of the letter, despite the speed fluctuations, a high level of control and regulation effort is necessary for this.

The invention has for its object to provide a method for applying self-adhesive labels on along a conveying path transported flat objects by means of a controlled driven pressure and applicator, in which the drive of the pressure and applicator drum is controlled with little effort so that each label is applied to the respective object at a predetermined distance from the leading edge of the article.

According to the invention the object is achieved by the features of claim 1.

Due to the surprising fact that the labels are applied to the articles in high quality even when the transport speed and the peripheral speed of the pressure and applicator drum differ (up to 50%), the pressure and applicator drum with a fixed Applizier peripheral speed operated, which corresponds to a mean transport speed of the objects. So that the desired distance of the label from the front edge of the object is maintained even with fluctuating transport speeds, the acceleration start time only has to be varied accordingly, depending on the measured speed and position of the respective item.

Since the pressure and applicator drum always on a uniform, corresponding to the average transport speed Circumferential speed must be accelerated, the acceleration time for an acceleration course in advance is determined taking into account the available drive torque and the constructive yielding moment of inertia of the pressure and applicator drum and considered as a constant in determining the start time.

It is advantageous to adapt the acceleration profile to the circumference of the pressure and applicator drum and the average transport speed to the available acceleration time and the acceleration path. For this purpose, the pressure and applicator drum is accelerated beyond the peripheral speed corresponding to the average transport speed and then decelerated to the peripheral speed corresponding to the average transport speed.

It is also advantageous to adapt the braking phase to time conditions by briefly increasing the peripheral speed over the application speed.

In a further advantageous embodiment, a different acceleration profile is defined for each transport speed range.

The invention will be explained in more detail with reference to the drawing in an embodiment.

FIG 1

eine schematische Seitenansicht einer Vorrichtung zum Aufbringen von selbstklebenden, trägerlosen Etiketten auf flache Gegenstände,

FIG 2

eine schematische Seitenansicht der Vorrichtung gegenüber der Darstellung in FIG 1 um 90° geschwenkt, mit bestimmten Zeitpunkten während des Transports eines Gegenstandes,

FIG 3

den Geschwindigkeits-Zeitablauf für die Antriebe der Vorrichtung zum Etikettieren.

Show

FIG. 1

a schematic side view of an apparatus for applying self-adhesive, strapless labels on flat objects,

FIG. 2

a schematic side view of the device relative to the illustration in FIG 1 pivoted by 90 °, with certain times during the transport of an object,

FIG. 3

the speed-timing for the drives of the device for labeling.

A self-adhesive label strip 1 is withdrawn from a supply roll 2 by a per se known Etikettenstreifenabrolleinrichtung 3 in strip form and fed to a Etikettenförder- and -schneidevorrichtung 4.

In the label conveying and cutting device 4, the label strip 1 is advanced onto a pressure and applicator drum 17 perpendicular to the transport plane of the flat objects 20 according to the required length and cut off when the pressure and applicator drum 17 is stationary. For this purpose, the label strip 1 is guided over a shaped guide 7 which merges in the label strip feed direction 5 of a slightly curved or non-curved guide surface at the entrance into one of the labels receiving surface of the pressure and applicator drum 17 adapted curvature having guide surface at the output.

In the surface of the guide 7 are openings which are connected to a vacuum source 6. In the guide 7, a motor-driven friction wheel, consisting of friction wheel 8 with drive 9 and pinch roller 10, integrated. Thus, the label strip 1 in the direction of the labeling device 11, consisting of the pressure and applicator drum 17, which also has connected to the female part to a vacuum source 19 openings, a drum drive 18 and a spring-mounted counter-roller 26, pushed and even in a cylindrical shape transferred.

After using the Reibradantriebs the label strip 1 was advanced to a certain extent within freely determinable height 12 above the knife means, the knife drive 13 moves the knife 14 on the label strip 1 on the counter blade 15 and shears a label 16. The label 16 is now supported only by the pressure and applicator drum 17.

On a suitable means of transport, not shown, e.g. a lid tape system are transported in the flat objects trapped, the labels to be labeled 20 along a path on the side facing away from the label conveying and cutting device 4 side of the labeling device 11 passed.

During the cutting of the label strip 1, the pressure and applicator drum 17 stops. Thereafter, it is accelerated with the label 16. By controlling, as will be described in more detail, the regulation of the movement sequence of the pressure and applicator drum so that upon arrival of the part of the pressure and applicator drum 17 with the label 16 on the article web a pinpoint acquisition of the self-adhesive label 16 by the object 20 is possible. The jacket of the pressure and applicator drum 17 is formed in a first region and a second region. The first cladding region has a circular curvature, wherein the center of the circle lies in the axis of rotation. In the second cladding region, the lateral surface is displaced inwardly to the extent that a disturbing contact of the objects 20, which are provided with labels, for example in a second, subsequent device, in the rest position is avoided. This lateral surface may also have the same circular curvature as in the first cladding region, only the center of the circle is displaced beyond the axis of rotation. Both jacket areas are connected by corresponding transition areas. This causes on the one hand the pressure and applicator drum 17 can not protrude into the article web during rest periods, eg when label cutting or Applizierpausen and thus the articles 20 or parts thereof can not be influenced. On the other hand, when applying a certain uniform pressure against the flat objects to be exercised around the self-adhesive label 16 to pass. To support the label transfer to the objects 20 can be generated by the follower pinch roller 26, a back pressure.

This effect achieved by the different shell regions of the pressure and applicator drum 17 with a spatially fixed axis of rotation can also be achieved if the pressure and applicator drum 17 is designed as a circular cylinder, and if it is movably mounted in the direction of the articles 20. For application, it is then moved towards the object so that the label can be pressed on, and when not applied, it is moved back so that contact with the objects 20 is avoided. This embodiment is not shown in the drawing, but can be readily realized by a person skilled in the art due to his skill.

A labeling device for letters is shown schematically in FIG.

• 1. Etikettvorschub;
• 2. Etikett schneiden;
• 3. aktuelle Geschwindigkeit messen, Startzeitpunkt für die Andruck- und Appliziertrommel 17 bestimmen und Trommel zum berechneten Zeitpunkt starten, dabei ist der Bewegungsablauf ein komplexer Vorgang, der sich aus wiederholten Beschleunigungs-, Brems- und Konstantgeschwindigkeitsphasen zusammensetzt;
• 4. Etikett applizieren;
• 5. Trommel abbremsen und in Ausgangsposition stoppen.

The labeling process always takes place in the following steps:

• 1. label feed;
• 2. cut the label;
• 3. measure the current speed, determine the starting time for the pressure and applicator drum 17, and start the drum at the calculated time, the motion being a complex process composed of repeated acceleration, braking and constant speed phases;
• 4. Apply the label;
• 5. Decelerate the drum and stop it in the starting position.

The following diagram describes the basic labeling process.

• 1. Zum Zeitpunkt t₀ (durch das Lettertracking der Maschinensteuerung bestimmt) sendet die übergeordnete Maschinensteuerung eine sendungsbezogene Botschaft an die Etikettiersteuerung mit folgenden Informationen:
  • Brief Id,
  • Etikett/kein Etikett,
  • Etiketthöhe.
• 2. Das Passieren der Sendungsvorderkante t₁ an Lichtschranke LB₁ startet den Etikettenvorschub. Erfolgt der Etikettenvorschub am Ende des vorherigen Appliziervorganges, dann muss sichergestellt werden, dass die Andruck- und Applizier-Trommel die Ausgangsposition vor dem Beginn des schneidens erreicht hat.
• 3. Start des Messerantriebes zum Zeitpunkt t₂. Die Bewegung des Messers wird so synchronisiert, dass der Schnitt erst nach Abschluss des Etikettenvorschubes beginnt. Der Messerantrieb vollführt bei jedem Schnitt einen 360° Umlauf, die Endlage wird durch einen Positionsgeber überwacht.
• 4. Messung der aktuellen Sendungsgeschwindigkeit mit den Lichtschranken LB2 und LB3. Aus der gemessenen Laufzeit t₄ - t₃, die ein Maß für die aktuelle Geschwindigkeit ist, wird der Startzeitpunkt t₅ für die Andruck- und Appliziertrommel 17 berechnet. Diese Messung gewährleistet eine höhere Genauigkeit gegenüber einer üblichen indirekten Messung der Geschwindigkeit über den Bandtakt, da das Band Schwingungen unterworfen ist.
  Es wurde überraschenderweise festgestellt, dass eine Differenzgeschwindigkeit zwischen Brieflauf und Andruck- und Appliziertrommel 17 in weiten Grenzen (<50%) unkritisch für den Etikettier-Applikations-Vorgang ist. Davon ausgehend wird für bestimmte Bandgeschwindigkeitsbereiche jeweils eine konstante Andruck- und Appliziertrommel-Geschwindigkeit in der Konzeption zugrunde gelegt. Die bandgeschwindigkeitsabhängige Korrektur der horizontalen Etikettenposition erfolgt über die Variation des Startzeitpunktes der Trommel in Bezug auf die Sendungsvorderkante.
• 5. Start der Appliziertrommel t₅. Der Beschleunigungsvorgang findet nach einer vorher (off-line) bestimmten Trajektorie statt und gewährleistet die entsprechende horizontale Positioniergenauigkeit. Dabei trifft die Etikettenvorderkante zum Zeitpunkt t₆ mit dem Brief zusammen (Merge Point).
• 6. Nach dem Ende der Applikation t₇ erfolgt zum Zeitpunkt t₈ der Beginn der Bremsphase, bis die Andruck- und Appliziertrommel 17 sich wieder in der Ausgangsposition befindet.
• 7. Nach dem Applizieren des Etiketts auf der Sendung wird die Andruck- und Appliziertrommel in die Ausgangsposition gefahren. Diese Position wird durch einen Positionsgeber überwacht.
• 8. Ein Etikettüberprüfer besteht aus einem Farbmarkensensor und einer Referenzlichtschranke für die Brief-Vorderkante. Die Brief-Vorderkante wird zum Zeitpunkt t₇ und die Etikettvorderkante zum Zeitpunkt t₈ bestimmt. Die Differenz repräsentiert bei der aktuellen gemessenen Geschwindigkeit v_i die Etikettposition auf der Sendung. Sendungen mit fehlenden Etiketten bzw. zu großen Positionierabweichungen des Labels werden rejektiert. Systematische Positionsabweichungen werden zur Langzeit-Nachregelung der Applikator-Steuerung genutzt.
• 9. Nach t₈ wird eine Ergebnis-Mitteilung an die übergeordnete Maschinensteuerung mit folgendem Inhalt geschickt:
  • Brief Id (0 representiert, Phantom Mailpiece'),
  • Etikett-Status (O.k., Failed),
  • Etikett-Position (bezogen auf die Sendungsvorderkante).

The processes of the label process are controlled by the letter run. The following times t _i vary with the dynamics of successive labeling operations.

• 1. At time t ₀ (determined by the machine controller's Lane Tracking), the higher-level machine controller sends a message-related message to the labeling controller with the following information:
  • Letter Id,
  • Label / no label,
  • Label height.
• 2. Passing the front end of the shipment t ₁ to the light barrier LB ₁ starts the label advance. If the label feed occurs at the end of the previous application, make sure that the pressure and applicator drum has reached the home position before cutting.
• 3. Start of the knife drive at time t ₂ . The movement of the knife is synchronized in such a way that the cut does not begin until the label feed has been completed. The knife drive performs a 360 ° rotation with each cut, the end position is monitored by a position encoder.
• 4. Measurement of the current shipment speed with the light barriers LB2 and LB3. From the measured transit time t ₄ -t ₃ , which is a measure of the current speed, the starting time t ₅ for the pressure and applicator drum 17 is calculated. This measurement ensures a higher accuracy compared to a conventional indirect measurement of the speed over the belt stroke, since the belt is subjected to vibrations.
  It has surprisingly been found that a differential speed between lettering run and pressure and applicator drum 17 within wide limits (<50%) uncritical for the labeling application process. Based on this, a constant pressure and applicator drum speed is used in the design for certain belt speed ranges. The tape speed-dependent correction of the horizontal label position is achieved by varying the start time of the drum with respect to the leading edge of the mailing.
• 5. Start of applicator drum t ₅ . The acceleration process takes place after a previously (off-line) certain trajectory and ensures the corresponding horizontal positioning accuracy. The label leading edge coincides with the letter at time t ₆ (merge point).
• 6. After the end of the application t ₇ takes place at the time t _8, the beginning of the braking phase until the pressure and applicator drum 17 is again in the starting position.
• 7. After applying the label on the shipment, the pressure and applicator drum is moved to the starting position. This position is monitored by a position encoder.
• 8. A label checker consists of a color mark sensor and a reference photocell for the letter leading edge. The letter leading edge is determined at time t ₇ and the label leading edge at time t ₈ . The difference represents the label position on the program at the current measured speed v _i . Shipments with missing labels or large positioning deviations of the label are rejected. Systematic position deviations are used for long-term readjustment of the applicator control.
• 9. After t ₈ , a result message is sent to the higher-level machine control with the following contents:
  • Letter Id (0 represents 'Phantom Mailpiece'),
  • Label Status (Ok, Failed),
  • Label position (relative to the front of the shipment).

• Der Zyklus wird durch eine Start-Mitteilung ausgelöst und beginnt mit dem Etikettvorschub (t₁₁). Während des Vorschubes wird die Sendungsgeschwindigkeit gemessen und der Messerantrieb gestartet (t₁₂),
• Schnitt nach Abschluss des Vorschubes (t_12a, t_12b),
• Trommelstart (t₁₅) nach dem Schnittende (t_12b),
• Das Etikett trifft zum Zeitpunkt t₁₆ mit der Sendung zusammen und wird danach auf die Sendung abgerollt,
• Der folgende Etikettzyklus beginnt schon vor dem Erreichen Ausgangsposition der Etikett-Trommel (t₂₀),
• Erreichen der Trommel-Ausgangsposition (t₁₉),
• Um die Abbremszeit der Andruck- und Appliziertrommel zu verkürzen, wird diese noch einmal kurz über die Appliziergeschwindigkeit beschleunigt und dann abgebremst.

FIG. 3 shows the speed-time sequence for the drives directly responsible for the labeling process.

• The cycle is triggered by a start message and begins with the label feed (t ₁₁ ). During the feed, the mailing speed is measured and the knife drive is started (t ₁₂ ),
• Cut after completion of the feed (t _12a , t _12b ),
• Drum start (t ₁₅ ) after the cut end (t _12b ),
• The label meets at the time t ₁₆ with the consignment and is then unrolled on the program,
• The following label cycle begins even before the initial position of the label drum (t ₂₀ ) is reached,
• Reaching the drum starting position (t ₁₉ ),
• To shorten the deceleration time of the pressure and applicator drum, it is again accelerated briefly over the Appliziergeschwindigkeit and then braked.

t₁₀

Sendungs-Id-Message von der übergeordneten Steuerung

t₁₁

Start Etikettenvorschub

t₁₂

Start Messerantrieb

T_12a, t_12b

Beginn, Ende Etiketten-Schnitt

T₁₅

Start Andruck- und Appliziertrommel

T₁₆

Beginn der Etikett-Applikation (Mergepoint)

T₁₇

Ende der Applikation

T₁₈

Beginn der Bremsphase

T₂₀

Start Etikettenvorschub des nächsten Etikettenzyklus

T₁₉

Erreichen der Trommel-Ausgangsposition

Where:

t ₁₀

Shipment ID message from the higher-level controller

t ₁₁

Start label feed

t ₁₂

Start knife drive

T _12a , t _12b

Beginning, end label cut

T ₁₅

Start pressure and applicator drum

T ₁₆

Start of the label application (Mergepoint)

T ₁₇

End of the application

T ₁₈

Beginning of the braking phase

T ₂₀

Start label feed of the next label cycle

T ₁₉

Reaching the drum home position

In normal operation, the drive belts run at a constant speed. The current shipment speed is determined by a transit time measurement between the measuring light barriers LB2 and LB3.

The current shipment speed is determined by measuring the shipment runtime t ₉ between the measuring light barriers LB 2 at the position x ₃ and LB ₃ at the position x ₄ . In this case, a constant transmission speed between the light barrier LB2 and the pressure and applicator drum 17 is required for a short time. $$\begin{array}{c}\text{(I) t}{}_{\text{9}}\text{= t}{}_{\text{4}}\text{- <figure-callout id="3" label="t" filenames="imgf0001.png" state="{{state}}">t</figure-callout>}{}_{\text{3}}\end{array}$$

After the shipment has passed the second measuring photocell at x ₄ , the runtime (t ₆₄ ) can be extrapolated to the merge point (x ₆ ). $$\begin{array}{c}\text{(II) t}{}_{\text{64}}\text{= t}{}_{\text{6}}\text{- <figure-callout id="4" label="t" filenames="imgf0001.png" state="{{state}}">t</figure-callout>}{}_{\text{4}}\text{= t}{}_{\text{9}}\text{*}\frac{\text{x}{}_{\text{6}}\text{- x}{}_{\text{4}}}{\text{x}{}_{\text{4}}\text{- <figure-callout id="3" label="x" filenames="imgf0001.png" state="{{state}}">x</figure-callout>}{}_{\text{3}}}\end{array}$$

The control concept assumes that for a defined range of belt speed, the pressure and applicator drum 17 is always accelerated with the same speed trajectory and therefore always requires the same time from the start to the merge time. Thus, the drum acceleration time T _{Tr is} a constant parameter of the tape speed range. The t ₄ related start time t _{5 of} the drum then results from (III). $$\begin{array}{c}\text{(III) <figure-callout id="5" label="t" filenames="imgf0001.png" state="{{state}}">t</figure-callout>}{}_{\text{5}}\text{= <figure-callout id="4" label="t" filenames="imgf0001.png" state="{{state}}">t</figure-callout>}{}_{\text{4}}\text{+ t}{}_{\text{64}}\text{- T}{}_{\text{Tr}}\end{array}$$

Claims (4)

1. Method for the application of self-adhesive labels to flat objects transported along a conveying path, by means of a pressure and applicator drum (17) driven under control, the respective label (16) being pushed onto the pressure and applicator drum (17) when the latter is at rest and held on it by means of vacuum, the pressure and applicator drum (17) then being accelerated in such a way that the peripheral speed of the label (16) on the pressure and applicator drum (17) during application for specific transport speed ranges always corresponds to a defined, average transport speed of the flat objects (20) and, following the application of the label (26), the pressure and applicator drum (17) being braked in such a way that it comes to a standstill again in the initial position after one revolution, the method comprising the steps:

   - off-line, before the application procedures, determining the acceleration times of the acceleration profiles, respectively the same in the specific transport speed ranges, from the starting time of the pressure and applicator drum (17) as far as the peripheral speed, corresponding to the defined, average transport speed of the objects (20), of the circumferential region accommodating the labels (16),

   - measuring the times at which the front edge of the respective object (20) passes two sensor devices (LB2, LB3) located one after another in the transport path before the pressure and applicator drum (17) and determining the starting time of the pressure and applicator drum (17) in accordance with the relationship $$\begin{array}{c}\mathit{\text{t}}{\text{}}_{\mathit{\text{5}}}\text{=}\mathit{\text{t}}{\text{}}_{\text{4}}\text{+(}\mathit{\text{t}}{\text{}}_{\text{4}}\text{-}\mathit{\text{t}}{\text{}}_{\text{3}}\text{)*}\frac{\mathit{\text{x}}{\text{}}_{\text{6}}\text{-}\mathit{\text{x}}{\text{}}_{\text{4}}}{\mathit{\text{x}}{\text{}}_{\text{4}}\text{-}\mathit{\text{x}}{\text{}}_{\text{3}}}\text{-}\mathit{\text{T}}{\text{}}_{\mathit{\text{Tr}}}\end{array}$$

   

   where

   x₃ is the position of the first sensor device (LB2) in the transport direction,

   x₄ is the position of the second sensor device (LB3) in the transport direction,

   x₆ is the position at which the front edge of the label and object are led together,

   t₃ is the time: front edge of the object at x₃,

   t₄ is the time: front edge of the object at x₄,

   t₅ is the starting time of the pressure and applicator drum,

   T_Tr is the acceleration time of the pressure and applicator drum to a peripheral speed, corresponding to the respective average transport speed of the objects, of the circumferential region accommodating the labels.
2. Method according to Claim 1, the pressure and applicator drum (17) being accelerated in the acceleration profile to an appropriate peripheral speed above the average transport speed and then being braked to the peripheral speed corresponding to the average transport speed.
3. Method according to Claim 1, following the application of the label, the pressure and applicator drum being accelerated briefly above the application speed and only then being braked.
4. Method according to Claim 1, a different acceleration profile being defined for each selected transport speed range.

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