EP3383751B1 - System for feeding a label stack - Google Patents

Description

The present invention relates to a system for feeding a stack of labels comprising a guide and a slide guided on the guide, which carries a biasing element for a stack of labels. The carriage is biased against a removal position on the guide, which leads to the label stack being positioned at the removal position in such a way that the foremost label of the label stack is moved by means of a driver device, e.g. a glue segment can be removed. The carriage can be moved along the guide by means of a drive mechanism. The drive mechanism is driven by a drive motor. This moves the carriage from a working position to a retracted release or fill position for the label stack. In the prior art, the label stack is pressed into the removal position by means of a spring device, which on the one hand has the advantage that when a label is removed, the entire label stack can move somewhat backwards. This is important because when a label is removed the driver device e.g. presses with the glue segment into the stack of labels and thus pushes it backwards from the removal position by a play clearance Δs. The spring device can easily accommodate this game. A disadvantage of this device is, however, that the force acting on the label stack depends on the degree of filling, i.e. is of the thickness of the stack of labels and that on the other hand, the entire device is relatively complicated and expensive.

A system according to the preamble of claim 1 is here US 4,978,416 known.

It is therefore an object of the invention to provide a simple system for feeding a stack of labels, which enables a simple and constant feeding function regardless of the thickness of the stack of labels.
This object is achieved with a system according to claim 1. Furthermore, the object is achieved by a method according to claim 12. Advantageous developments of the invention are the subject of the associated subclaims.
According to the invention, the drive mechanism obtains the biasing force for the bias of the carriage in the removal position from the torque of the drive motor. In contrast to some prior art, where a spring device presses the stack of labels into the removal position, it is now the torque of the running driven drive motor that pushes the stack of labels into the removal position. This system has the advantage that the pre-tensioning force acting on the label stack is independent of the thickness of the label stack. It does not decrease as in the prior art when the stack of labels becomes smaller.
On the other hand, one saves the rather complicated spring mechanism that previously exerted the prestressing force on the prestressing element.
Any type of motor, ie an electric or pneumatic or hydraulic motor, can be used as the drive motor, the motor being stationary, ie the life of the motor is not impaired when driving energy is applied while the motor is stationary. This makes it possible for the motor to be continuously drivable so as to exert the required prestressing force on the prestressing element via its torque. The biasing element can be, for example, a slider if the stack of labels slides on a base, or a receiving element if the entire stack of labels is held by the biasing element. The removal position is preferably at one end of the guide, but can also be arranged somewhat beforehand.
The slide is mounted on the guide, in particular via sliding elements or on rollers, in such a way that it can be moved back and forth on the guide with as little resistance as possible. The propulsion or the movement of the carriage is realized by the drive mechanism. There are different known solutions here. In a first embodiment, the drive mechanism has a rotating flexible drive means which is driven by the drive motor and which is stretched between at least two deflection rollers. The carriage is connected to the drive means in particular via a driver. The drive means is preferably a drive belt, in particular an endless belt, which can either be smooth or toothed. The drive motor either drives the drive means directly, for example via a toothed roller or a friction roller, or drives one of the deflection rollers, which is currently the more common solution. The carriage is then connected at one point to the drive means via a driver and is moved along the guide via the drive means.
In another embodiment, the drive mechanism is designed as a spindle, more precisely as a threaded spindle, which, for example, simultaneously form the guide for the slide can. The spindle is rotated by the drive motor and a threaded nut-like threaded element that meshes with the spindle is provided on the slide. Rotation of the spindle thus moves the carriage on the spindle back and forth in accordance with the direction of rotation and speed of rotation of the spindle. As will be shown below, it is particularly advantageous if the thread pitch and also the other parameters of the thread of the spindle and the threaded element are selected such that the thread is not self-locking.

In contrast to the present invention, if a non-stationary motor is used, it is advantageous if the drive mechanism has a continuous slip clutch which is used when the pretensioning element of the carriage bears against the label stack and the motor continues to rotate nonetheless.
About this permanent slip clutch, which can be a friction clutch, for example, a certain torque is constantly transferred to the drive mechanism via the permanent slip clutch, and thus into a pressing force of the biasing element against the stack of labels.
The permanent slip clutch is preferably a permanent slip clutch which operates according to the magnetic hysteresis principle, which has the advantage that the permanent slip clutch is maintenance-free and largely unaffected by external influences, for example temperature. The transmitted torque is therefore solely dependent on the rotational speed of the drive motor. With such a continuous slip clutch, the pressure exerted on the stack of labels by means of the pretensioning element can thus be set very reliably reproducibly and precisely.
In principle, it is possible for the guide to have a curved course. For reasons of simple operational management, however, the guide is preferably designed as a linear guide.
In a very simple embodiment, the drive motor is an electric motor, in particular a permanent magnet motor. It is particularly advantageous to use a closed-loop motor as an electric motor which, at least in the pressing operation, ie when the pretensioning element presses against the stack of labels, is torque controlled. Such a closed-loop motor is safe from standstill and, when stationary, applies a defined torque in accordance with the control of the closed-loop motor, with which a defined pretensioning force can be exerted on the pretensioning element. The torque is set via the control signals for the closed-loop stepper motor.

As has already been expressed above, when a label is removed from the label stack at the removal position, the label stack is pressed back briefly by a small movement play ΔS from the removal position by the driver device. The drive mechanism should therefore be able to absorb this movement play. Advantageously, therefore, between the drive motor and the biasing element, an elastic element, e.g. a spiral spring, a rubber element or helical springs are provided which allow a movement play ΔS of the prestressing element in the direction of the guide facing away from the removal position. In this way, the slide or the pretensioning element can avoid this removal movement ΔS without the motor being deflected against its drive direction. In principle, if this is possible, the drive mechanism could be built without the elastic element.

Preferably, the elastic element is arranged between the driver of the slide and the biasing element, in which way the elastic element does not require a separate space in the drive mechanism, since the elastic element e.g. can be integrated into the sled. In the case of a spindle drive, the threaded element can thus be suspended as a driver on the slide between two coil springs, which are supported on the slide. In this way, the biasing element is movable relative to the threaded element in both directions by a certain amount of play, which should in any case be as large as the above-mentioned required movement play Δs. In principle, it is sufficient to provide only one helical spring, which enables the biasing element to deflect against the pressing direction of the stack of labels.

In the same way, the invention relates to a method for prestressing a slide that can be moved on a guide by means of a drive motor for prestressing a stack of labels into the removal position. According to the invention, the force for the pretensioning of the slide into the removal position from the torque of the Drive axis of the drive motor generated or derived. As has already been expressed above in the description of the system according to the invention, this has the advantage that no separate spring device is required to pretension the pretensioning element against the stack of labels. This has the advantage that the force is always the same regardless of the thickness of the label stack and that the entire mechanism is considerably simplified.
With regard to the further advantages and features, reference is made to the discussion of the system according to the invention.
A closed-loop stepper motor is preferably used as the drive motor, which is stationary and therefore does not require a device, such as a continuous slip clutch, in order to transmit the torque to the biasing element when the biasing element lies essentially immovably against the stack of labels.

Fig. 1

eine schematische Ansicht eines Zufuhrsystems mit einem Spindelantrieb;

Fig. 2

eine schematische Ansicht eines Zufuhrsystems mit einem Endlosband-Antrieb;

Fig. 3

eine Ansicht analog zu Figur 2, bei welcher der Schlitten mittels eines elastischen Elements an einem Mitnehmer des Endlosband-Antriebs gehalten ist;

Fig. 4

eine schematische Ansicht eines nicht erfindungsgemäßen Systems ähnlich zu Fig. 1 mit Spindelantrieb und Dauerschlupfkupplung;

Fig. 5

eine Vergrößerung eines nicht erfindungsgemäßen Systems ähnlich Fig. 2 unter Verwendung einer Dauerschlupfkupplung.

Alternatively, but not according to the invention, a continuous slip clutch can be used for connecting the drive axis of this drive motor to a drive mechanism for the slide, so that the torque of the drive motor is transmitted to the drive mechanism via the permanent slip clutch. In this case, the motor can continue to rotate when the biasing element is against the stack of labels. The motor therefore does not have to be standstill-resistant, which allows the use of a wide range of motors, not just electric motors.
For the derivation of the torque, it is irrelevant whether the drive axis of the motor rotates or not. In the latter case, the motor only has to be stable at a standstill, ie actuating the motor when its rotation is blocked must not significantly impair the life of the motor.
The drive motor is constantly driven in a removal operation, in which labels are removed from the stack of labels by means of a driver device not belonging to the invention, which means that the torque generated by the constant drive of the drive motor is continuously converted into a biasing force of the biasing element on the label stack becomes. Any type of linear is suitable for converting this rotational torque into a preload force Drive mechanism, for example a spindle drive or an endless belt drive, as already stated above.
The prestressing element is preferably held elastically on the carriage in such a way that the prestressing element can be moved away from the removal position by a play Δs without this movement being transmitted to the drive mechanism or even the drive motor. The required play, which is necessary so that a driver device can remove a single label from the stack of labels, is thus achieved solely by the elastic mounting of the slide by means of an elastic element.
In another embodiment, an elastic mounting of the prestressing element on the slide is dispensed with, as a result of which the movement play Δs cannot be absorbed or compensated for by elastic deformations or play. If, as already mentioned above, the thread pitch and also the other parameters of the thread of the spindle and the threaded element are selected so that the thread is not self-locking, the distance Δs through the slide can be carried out by the spindle through the Backward movement of the carriage by the distance Δs is rotated backwards by a corresponding angle of rotation against the permanent torque of the motor.
If the label was then removed from the label stack, the carriage is moved back to the starting position by the permanent torque of the motor.
It is understood by the person skilled in the art that the above-mentioned exemplary embodiments can be combined with one another. It is further understood that individual elements of the claims can be provided one or more times. The biasing element can be a simple slider, which rests on the back of the label stack and advances the label stack into the removal position, or the biasing element can have a complete receptacle for the label stack. A stop for the position of the label stack is preferably provided at the removal position, at which position a driver device then engages and pulls a label off the label stack, for example by means of a glue segment. A system according to the invention could also be used to pretension several stacks of labels at the same time in a removal position.
The invention is described below, for example, using the schematic drawing. In this show:

Fig. 1

a schematic view of a feed system with a spindle drive;

Fig. 2

a schematic view of a feed system with an endless belt drive;

Fig. 3

a view similar to Figure 2 , in which the carriage is held by means of an elastic element on a driver of the endless belt drive;

Fig. 4

a schematic view of a system not according to the invention similar to Fig. 1 with spindle drive and permanent slip clutch;

Fig. 5

an enlargement of a system not according to the invention is similar Fig. 2 using a continuous slip clutch.

Fig. 1 shows a feed system 10 for pretensioning a stack of labels 12 in a removal position 14. For this purpose, the stack of labels 12 slides on a smooth surface 16 (for example a metal feed surface) and is pushed into the removal position 14 by a slide 18 on its rear side facing away from the removal position 14. The slide forms the biasing element of the feed system according to the invention. The system also has a drive motor 20 and a drive mechanism 22, which has a spindle 24 rotated by the drive motor 20 and a carriage 26 guided on the spindle 24. The carriage 26 is movably guided as a driver on the spindle by means of a non-rotatable threaded element 28. The threaded element 28 is supported, for example, via two helical springs 30, 32 against two support walls 34, 36 of the slide 26. The slider 18 is fixed to the carriage 26. Due to the resilient mounting of the slide 26 on the threaded element 28, the slide 26 and thus the slide 18 can be moved somewhat in the direction of the guide, in both directions according to the double arrow shown around the threaded element 28. This plays a role, as will be explained below. When the label is removed by means of a driver device, for example a glue segment, the glue segment presses against the label stack 12 with the force F, the entire label stack being pressed away from the removal position 14 in the direction of the slide 18 by the play clearance Δs. This movement play Δs is absorbed by the coil springs 30, 32, which hold the slide 26 resiliently on the threaded element 28.

The biasing force VF of the slider 18 against the label stack 12 is derived from the torque of the drive motor 20 which is constantly driven during the removal of labels. In contrast to the prior art, where the motor is switched off in the removal position of the label stack and the pretensioning force is exerted solely via a spring device, in the present invention this pretensioning force VF is generated by the torque which is generated by the current actuation of the drive motor 20 during the removal generated from labels from the label stack. This torque is converted via the threaded element 28 into the biasing force VF, which presses the slider 18 against the label stack 12 in the direction of the removal position 14.

In another embodiment, there is no elastic mounting of the prestressing element on the slide 18, as a result of which the movement play Δs cannot be absorbed or compensated for by elastic deformations or play.
If, as already mentioned above, the thread pitch and also the other parameters of the thread of the spindle and the threaded element are selected so that the thread is not self-locking, the distance Δs through the slide can be carried out by the spindle through the Backward movement of the carriage by the distance Δs is rotated backwards by a corresponding angle of rotation against the permanent torque of the motor.
If the label was then removed from the label stack, the carriage is moved back to the starting position by the permanent torque of the motor.

In the figures, identical or functionally identical elements are provided with the same reference symbols.

The feed system 14 according to the invention Fig. 2 has one of Fig. 1 deviating drive mechanism 42, which consists of a flexible drive means 44, preferably in the form of an endless belt, which is stretched between two deflection rollers 46, 48. Between the two deflection rollers 46, 48, a linear guide 50 for the carriage 26 is also formed, which, as in FIG Fig. 1 can be built. The difference between the carriage 26 from the embodiment of FIG Fig. 2 and the carriage 26 from the embodiment of FIG Fig. 1 is that in this Embodiment of the Fig. 2 the driver is not a threaded element, but simply an element which is fastened to the endless belt 44, so that the two coil springs 30, 32 act on this element. Thus, in this case as well, the carriage 26 is suspended elastically on the drive belt 44 in the direction of the linear guide 50, which makes it possible for the slider 18 to remove the label 18 from the label stack 12 by the movement clearance Δs required by the driver device to the rear, ie from the Removal position 14 away, can dodge.
Fig. 3 shows one too Fig. 2 largely analog system 60, which is based on system 40 Fig. 2 the only difference is that here the carriage 62 is connected to the endless belt 44 via a driver 64, the driver 64 being connected to the carriage 62 via an elastic element, for example a rubber element 66. In contrast to Fig. 2 So there are no coil springs, but an elastic rubber element for connecting the slide to the driver. Thus, in this embodiment too, the slider 18 can move backwards by the movement play ΔS when a label is removed from the label stack 12.
Fig. 4 again shows a to Fig. 1 largely identical system 70 with a drive mechanism containing a spindle drive 24, 26, 28. In contrast to the drive mechanism 22 Fig. 1 here, the drive mechanism 72 identifies the components of the drive mechanism 22 Fig. 1 Another slip clutch 74, which connects the spindle 24 to the shaft of the drive motor 20. This alternative thus allows the use of a non-stationary electric or hydraulic motor to apply the biasing force VF to the stack of labels 12 by means of the slider 18. Here too, the components of the drive mechanism 22 are preferably not designed to be self-locking in order to reverse the movement of the slider 18 in a reverse rotation of the spindle to be able to convert.
Alternatively, a permanent slip clutch 74 could also be provided between the slide 18 and the threaded element 28 arranged on the spindle, as a result of which, when the slide is moved backwards, the threaded element 28 is rotated about its longitudinal axis relative to the slide 26, but the spindle is not rotated backwards.

Finally shows Fig. 5 an alternative form of system 60 Fig. 3 . In this alternative form is between the shaft of the drive motor 20 and the idler pulley 46 of the endless belt drive mechanism 42, a continuous slip clutch 68 is provided, which can either be a friction clutch or a permanent slip clutch operating according to the magnetic hysteresis principle. In this way, the torque of the motor can be continuously transmitted to the drive mechanism, whereby the drive motor 20 can continue to rotate. Thus, the constant biasing force VF is transmitted to the label stack by means of the continuous slip clutch, the drive motor 22 not having to be stationary. This torque transmitted to the endless belt 44 is then converted via the driver of the carriage 26 into a biasing force VF of the slider 18 on the label stack 12.

The above-mentioned embodiments do not limit the subject matter of the application, but this can be varied within the scope of the following claims.

Reference list

10th

Feed system (first embodiment)

12th

Stack of labels

14

Removal position

16

Underlay (smooth metal underlay)

18th

Slider (preload element)

20

Drive motor

22

Drive mechanism (first embodiment)

24th

Spindle (rotating rod with external thread)

26

Carriage (first embodiment)

28

Threaded element (driver)

30th

first coil spring

32

second coil spring

34

first support wall of the slide

36

second support wall of the slide

40

Feed system (second embodiment)

42

Drive mechanism (second embodiment)

44

flexible drive means (endless belt)

46

first pulley

48

second pulley

50

Linear guide

60

Feed system (third embodiment)

62

Carriage (second embodiment)

64

Carrier

66

Rubber element (flexible element)

68

Permanent slip clutch

70

Feed system (fourth embodiment)

72

Drive mechanism (third embodiment)

74

Permanent slip clutch

Claims (15)

1. System for feeding a stack of labels (12), comprising a guide (24; 50), a carriage which is guided on the guide (26; 62), and has at least one urging element (18) for the stack of labels, said carriage being urged on the guide against a removal position (14) of the stack of labels, wherein the carriage (26; 62) can be moved along the guide by means of a drive mechanism (22; 42: 72) driven by a drive motor (20), wherein the drive mechanism (22; 42; 72) receives the urging force for the urging of the carriage (26; 62) into the removal position from the torque of the drive motor (20), characterised in that the drive motor is a static drive (20), with which the torque is generated by way of its drive axle, and the drive motor (20) is configured such that, in a removal operation, the torque is consistently generated by the constantly driven drive motor (20), wherein it is not of relevance for the derivation of the torque whether the drive axle of the drive motor (20) is rotating or not.
2. System according to claim 1, characterised in that the drive mechanism (22; 42; 72) comprises circulating flexible driving means (44), driven by the drive motor, which are tensioned between at least two deflection rollers (46, 48), wherein the carriage (26; 62) is connected to the drive means (44).
3. System according to claim 2, characterised in that the drive means (44) is a drive band.
4. System according to one of claims 2 to 3, characterised in that the drive motor (20) drives at least one of the deflections (46, 48).
5. System according to claim 1, wherein the drive mechanism (22; 72) comprises a (threaded) spindle (24) extending in the direction of the guide, and a threaded element (28), arranged at the carriage (26) and meshing with the (threaded) spindle (24), and wherein the (threaded) spindle (24) and the threaded element (28) are preferably configured as not self-locking.
6. System according to any one of the preceding claims, characterised in that the guide (50) is a linear guide.
7. System according to any one of the preceding claims, characterised in that the drive motor (20) is an electric motor.
8. System according to claim 7, characterised in that the electric motor (20) is a permanent magnet motor.
9. System according to 7 or 8, characterised in that the electric motor (20) is a closed-loop stepping motor, which, at least in press-on operation is torque-controlled.
10. System according to any one of the preceding claims, characterised in that at least one elastic element (30, 32; 66) is arranged between the drive motor (20) and the urging element (18), which allows for a movement play Δs of the urging element (18) in the direction of the guide (50) facing away from the removal position (14).
11. System according to claim 10, characterised in that the elastic element (30, 32; 66) is arranged between a driver pin (28) of the carriage (26; 62) and the urging element (18).
12. Method for feeding labels, making use of a carriage (26; 62) which can be moved by a drive mechanism (22; 42; 72) on a guide (50), and which comprises at least one urging element (18) for the stack of labels, said drive mechanism being driven by a drive motor (20), wherein the carriage is urged into a removal position (14), wherein the urging force (VF) for the urging of the carriage is generated by the torque of the drive motor (20), characterised in that the drive motor is a static drive motor (20), wherein the torque is generated by the drive axle of the motor, and that, in removal operation, the torque is consistently generated by the constantly driven drive motor (20), wherein it is not of relevance for the derivation of the torque whether the drive axle of the drive motor (20) is rotating or not.
13. Method according to claim 12, characterised in that, as the drive motor (20), use is made of a closed-loop-stepping motor.
14. Method according to any one of claims 12 to 13, characterised in that the urging element is held elastically or under spring action, in such a way that the urging element can be moved by a movement play Δs away from the removal position.
15. Method according to any one of claims 12 to 14, characterised in that a movement of the carriage (26) causes a movement of a spindle (24) and/or of a threaded element (28).

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