EP2897866B1 - Strapping device having a pivotable rocker - Google Patents

Description

The invention is defined by the claims.

The invention relates to a strapping device for strapping packaged goods with a strapping tape, which has a tensioning device for applying a tape tension to a loop of a strapping tape, the tensioning device being provided with a motor-driven tensioning wheel that can be rotated around a tensioning axis and is provided for engaging the strapping tape , the tensioning device further comprises a tensioning plate, with provision being made during a tensioning process carried out by the tensioning device that a single or multi-layer section of the strap is located between the tensioning wheel and the tensioning plate and is in contact with both the tensioning wheel and the tensioning plate, furthermore the clamping plate is arranged on a rocker pivotable by motor about a rocker axis in order to either increase or decrease a distance between the clamping wheel and the clamping plate by a pivoting movement of the rocker, as well as a connecting device for generating a d extraordinary connection, in particular a welded connection, at two superimposed areas of the loop of the strapping band by means of a connecting element, such as a welding element, which is provided for local heating of the strapping band

Such strapping devices are used for strapping packaged goods with a plastic strap. For this purpose, a loop of the respective plastic strap is placed around the packaged goods. As a rule, the plastic tape is pulled off a supply roll. After the loop has been completely placed around the packaged goods, the end area of the tape overlaps with a section of the tape loop. The strapping device is now placed on this two-layer area of the strap, the strap is clamped in the strapping device, strap tension is applied to the strap loop by means of the tensioning device, a closure is created by friction welding on the loop between the loaded strap layers. In this case, a friction shoe moving in an oscillating manner is used to press the belt in the area of two ends of the belt loop. The pressure and the heat generated by the movement melts what is usually plastic Tape locally for a short time. This creates a permanent connection between the two layers of tape that can at most be released again with great force. Thereafter or approximately at the same time, the loop is separated from the supply roll. The respective packaged goods are strapped as a result.

Strapping devices of the generic type are intended for mobile use, in which the devices should be carried by a user to the respective place of use and there should not be dependent on the use of externally supplied supply energy. The energy required for the intended use of such strapping devices for tensioning a strapping band around any packaged goods and for creating a seal is usually provided by an electric accumulator or by compressed air in previously known strapping devices. This energy is used to generate the strap tension applied to the strap by means of the tensioning device and a closure on the strapping strap. Strapping devices of the generic type are also intended to connect exclusively weldable plastic straps to one another.

In the case of mobile devices, a low weight is of particular importance in order to put as little physical strain as possible on the users of the strapping device when using the device. Likewise, for ergonomic reasons, the weight should be distributed as evenly as possible over the entire strapping device, in particular in order to avoid concentration of the weight in the head area of the strapping device. Such a concentration leads to unfavorable handling properties of the device. In addition, the most ergonomic and user-friendly handling of the strapping device is always aimed for. In particular, the possibility of operating errors and malfunctions should be as low as possible.

In the case of strapping devices of the generic type, it should also be ensured, as a further aspect of functional reliability, that no or at most little slip occurs between the tensioning wheel and the strapping even after higher strap tensions have been reached. On the one hand, slippage can prevent the belt tension values to be achieved from being reached. However, slippage can also lead to the tensioning process and thus the entire strapping process extended in time. Furthermore, due to the longer period of use of the respective strapping device per strapping and thus also the required amount of energy per strapping, slippage also means that the number of straps that can be achieved with one charge of the accumulator is reduced. Ultimately, however, slip also means that the belt tension value to be achieved may not be achieved and the belt is therefore not sufficiently tensioned, which can represent a safety risk. In order to avoid slippage as much as possible, or at least to reduce it, the tensioning wheel is usually provided with teeth and is pressed onto the tensioning plate with a pressure force. For this purpose, in previously known solutions, the pressing force can result from a spring with which the rocker with the tensioning wheel arranged on it presses against the band and the tensioning plate arranged below. However, these solutions are not particularly satisfactory when higher belt tensions are to be generated, since - as has been shown - this does not allow slip during the tensioning process to be prevented with sufficient certainty.

DE 20 2011 050797 U1 discloses a rocker arm assembly of a strapping machine comprising: a rocker arm comprising: a fulcrum end, a swing end, and a seat formed on the rocker arm located adjacent to the swing end.

The invention is therefore based on the object of creating a generic, in particular a mobile, strapping device of the type mentioned at the beginning with high functional reliability, in which the intended strap tensions can be applied to the strap safely and with as little slip as possible.

This object is achieved in a strapping device of the type mentioned according to the invention in that during the transmission of the motor drive movement to the tensioning wheel, as long as the tensioning wheel is in engagement with the band, a drive movement is carried out by means of a transmission means of the strapping device during the duration of the tensioning process swiveling rocker is transmitted, the Drive movement is provided for exerting a torque on the rocker. According to the invention, the torque exerted on the rocker can be used to increase the pressing force of the tensioning device against the strapping band. In a structurally simple solution, the torque exerted on the rocker by transmission means can originate from a motor, the drive torque of which increases the pressing force of the rocker against the band in the course of the tensioning process. It is preferred here if the motor-related increase takes place in such a way that it occurs primarily during or after an increase in the belt tension. It is advantageous here if a motor is used to generate the motor torque for the rocker, which also performs other drive movements. It is particularly favorable here if the motor and its drive movement are used, with which the tensioning wheel is also driven. On the one hand, a further motor can thereby be avoided, but the function according to the invention can still be exercised. On the other hand, the motor torque, which usually rises when the belt tension increases, can also be used to increase the pressing force. In a structurally particularly simple manner, this allows the rocker to be pressed against the band in a variable, voltage-dependent manner. The latter can preferably take place proportionally to the respectively applied belt tension.

According to the invention, a torque is exerted and transmitted on the rocker that is based on a force exerted on the tensioning device by the band at an engagement point of the band with the tensioning device. This force, the reaction of the tensioning force applied to the belt by the driven tensioning wheel, is picked up at a suitable point and transmitted to the rocker with a transmission device. In order to use as little construction effort as possible, the belt tensioning force acting on the tensioning wheel is used on the tensioning wheel itself. This uses the momentary torque acting on the tensioning wheel, which is introduced from the tensioning wheel into the transmission means of the tensioning device and is transmitted by these to the rocker.

According to a preferred aspect, it can be provided that the motorized drive movement for the tensioning device is also used, at least indirectly as a reaction, to use the rotational movement of the tensioning wheel driven by the motor and a pivoting movement of the rocker during the tensioning process, one of the with the strapping engaged standing tensioning wheel derived torque by means of transmission means in the Rocker can be introduced in order to increase a pressing force of the tensioning device against the band.

In a preferred embodiment of the invention, a transmission of the tensioning device, with which a motorized drive movement for the tensioning wheel is reduced or translated, can be wholly or partially part of the transmission means with which the force acting on the tensioning wheel and resulting from the belt tension from the belt the rocker is transferred.

According to a further, preferred aspect of the invention, means are provided for the band tension-dependent variable pressing of the tensioning wheel onto the strapping band. Thus, during the tensioning phase, the tensioning device is pressed against the strapping in a variable manner depending on the tension of the tape. In particularly advantageous embodiments of the invention, the belt tension generated by the tensioning process is thus used to advantageously increase the pressure of the tensioning wheel on the belt with steadily increasing belt tension . Slippage of the tensioning wheel during the tensioning process can be counteracted. With increasing belt tension, the contact pressure of the tensioning wheel on the belt and the tensioning plate also increases. In such embodiments, the invention enables a high pressure to be exerted on the belt when the belt tension is already high and the risk of slippage between the tensioning wheel and the belt is also particularly high when attempting to further increase the belt tension. The pressure force, which preferably increases automatically, i.e. without manual intervention, can counteract the increasing risk of slippage and thus ensure functional reliability and a fast strapping process even with high strap tensions. Since the reaction of the strapping tape to the action, namely the applied tape tension, as well as transmission means are used which are derived from the tensioning device, in particular from the tensioning wheel, and transmitted to the rocker, no intervention by an operator is required to achieve the effect according to the invention, the effect according to the invention is advantageously achieved automatically in the strapping device.

In a preferred embodiment of the invention, the transmission means, which advantageously represent an operative connection from the tensioning wheel to the rocker, can comprise a pivotable mounting of the rocker at least during the tensioning process and a rotatably or rotatably mounted gear element which is operatively connected to the tensioning wheel during the tensioning process . The reaction force of the band is preferably used as torque and is introduced into the rotatable or rotatable gear element, for example a planet carrier of a planetary gear. The rotatable or rotatable gear element should be supported against the rotary or rotational movement on a support element. The reaction force of the tensioning wheel can then be introduced into the rocker via or due to the support, whereby an additional torque acts on the rocker, which can be used to increase the pressing force of the rocker against the strapping. The transmission means can advantageously be wholly or partially a component of the tensioning gear, with which a motorized drive movement or a drive movement originating from some other energy supply is directed to the tensioning wheel at a suitable speed.

In a particularly preferred embodiment of the invention, motorized drive movements with identical directions of rotation of only one motor can be used not only for driving the tensioning wheel when tensioning the strapping but also for lifting the rocker. In addition to this, the belt tension-dependent variable pressing of the tensioning wheel onto the belt to be tensioned can also be carried out with the same drive movement. The dependency is provided in such a way that as the belt tension increases, the contact pressure exerted on the belt by the tensioning wheel also increases. Since the risk of slippage between the tensioning wheel and the belt increases with increasing belt tension, the risk of slippage can be counteracted by increasing the contact pressure. The motor drive movement when tensioning the strap can preferably be used in such a way that, during the tensioning process of the strapping tape, one of the strapping bands is transferred to the tensioning wheel by means of the tensioning wheel engaging the strapping tape and rotating against a strap tension acting counterforce is used to increase the contact pressure of the tensioning wheel tensioning wheel in the direction of the clamping plate.

According to a further, preferred aspect of the invention, a force resulting from the belt tension and acting in a gear mechanism, with which a drive movement is transmitted to the tensioning wheel, is to be made possible with little structural effort and ease of use. A solution for this further aspect of the invention, which can be significant in combination with the subject matter of claim 1, is described in claim 8. This thus relates to a locking device for use in a strapping device, with which a rotatable wheel can be clamped which is provided for transmitting a drive movement, in particular a gear wheel of a tensioning device of the strapping device. The locking device should have at least one clamping body which can be pivoted about a pivot axis and is arranged at a distance from the wheel, which can be pivoted from a release position to a locking position in which it - preferably with part of an arcuate contact surface - abuts against a substantially flat, i.e. free of form-locking element , Circumferential clamping surface of the wheel arrives, wherein the clamping body has a pivot radius which is greater than a distance between the pivot axis of the clamping body and the peripheral clamping surface of the wheel, and the direction of rotation of the clamping body around the pivot axis when moving from the release position to a clamping position in opposite directions of rotation such as the wheel to be clamped runs.

With such a locking device, locking of rotating gear wheels can be achieved in a structurally simple manner and in a very functionally reliable manner. The locking in the direction of rotation of the wheel can be maintained with little effort. The clamping force of the clamping body even increases automatically if an attempt is made to turn the wheel further by increasing the torque.

The locking device can be used to advantage, in particular, for releasably locking a wheel of a gear that belongs to a gear with which a drive movement is to be transmitted to a tensioning wheel of the tensioning device of a strapping device. In this context, it can be provided in particular to clamp a wheel of a planetary gear, with which the drive movement is to be transmitted to the tensioning wheel. With or at least with the aid of a clamping of the wheel to be clamped, one of at least two output directions of the transmission can preferably be determined, in particular an output direction of the transmission on the tensioning wheel, so that the belt can be tensioned,

It can also be advantageously provided that when the clamping is released, the belt tension acting on the tensioning wheel and the gear is at least partially, preferably completely, relieved. Since with such locking devices comparatively low release forces are required to release the clamping even at high strap tension values, the invention results in particularly functionally reliable and easy-to-use strapping devices. The low operating or actuation forces also make it possible to dispense with a rocker lever, with which high torques were previously generated in previously known strapping devices for lifting the rocker from the tensioned strap. Instead of a long rocker lever, a button or button can now be used, with which the tension-releasing process takes place.

Fig. 1

eine beispielhafte Umreifungsvorrichtung in einer perspektivischen Darstellung;

Fig. 2

eine Explosionsdarstellung der Spanneinrichtung der Umreifungsvorrichtung aus Fig. 1 zusammen mit dem Motor;

Fig. 3

eine perspektivische Darstellung der Spann- und der Verschlusseinrichtung der Umreifungsvorrichtung aus Fig. 1;

Fig. 4

eine weitere perspektivische Darstellung der Spann- und der Verschlusseinrichtung der Umreifungsvorrichtung aus Fig. 1;

Fig. 5

eine Explosionsdarstellung eines Ausführungsbeispiels der Spanneinrichtung der Umreifungsvorrichtung aus Fig. 1 zusammen mit dem Motor;

Fig. 6

eine perspektivische Darstellung der Spann- und der Verschlusseinrichtung der Umreifungsvorrichtung aus Fig. 1;

Fig. 7

eine weitere perspektivische Darstellung der Spann- und der Verschlusseinrichtung der Umreifungsvorrichtung aus Fig. 1;

Fig. 8

eine Seitenansicht auf die Spanneinrichtung aus Fig. 5, in der sich eine Wippe in einer ersten Schwenkendposition befindet;

Fig. 9

eine Seitenansicht auf die Spanneinrichtung aus Fig. 5, in der sich die Wippe in einer zweiten Schwenkendposition befindet;

Fig. 10

eine Seitenansicht auf die Spanneinrichtung aus Fig. 2, in der sich die Wippe in einer Position mit hohem Andrückkraft gegen eine Spannplatte befindet;

Fig. 11

eine Seitenansicht auf die Spanneinrichtung aus Fig. 2, in der sich die Wippe in einer Position mit im Vergleich zur Fig. 10 geringerer Andrückkraft gegen eine Spannplatte befindet;

Fig. 12

eine perspektivische Teildarstellung der Spann- und der Sperreinrichtung;

Fig. 13

eine Schnittdarstellung der Spann- und Sperreinrichtung;

Fig. 14

eine Prinzipdarstellung der geometrischen Verhältnisse einer Sperreinrichtung.

The invention is explained in more detail purely schematically with reference to the figures, which show:

Fig. 1

an exemplary strapping device in a perspective view;

Fig. 2

an exploded view of the tensioning device of the strapping device Fig. 1 together with the engine;

Fig. 3

a perspective view of the tensioning and locking device of the strapping device Fig. 1 ;

Fig. 4

a further perspective view of the tensioning and locking device of the strapping device Fig. 1 ;

Fig. 5

an exploded view of an embodiment of the tensioning device of the strapping device Fig. 1 together with the engine;

Fig. 6

a perspective view of the tensioning and locking device of the strapping device Fig. 1 ;

Fig. 7

a further perspective view of the tensioning and locking device of the strapping device Fig. 1 ;

Fig. 8

a side view of the clamping device Fig. 5 , in which a rocker is in a first pivot end position;

Fig. 9

a side view of the clamping device Fig. 5 in which the rocker is in a second pivot end position;

Fig. 10

a side view of the clamping device Fig. 2 in which the rocker is in a position with high pressure against a clamping plate;

Fig. 11

a side view of the clamping device Fig. 2 , in which the rocker is in a position with compared to Fig. 10 there is less pressing force against a clamping plate;

Fig. 12

a perspective partial view of the tensioning and locking device;

Fig. 13

a sectional view of the tensioning and locking device;

Fig. 14

a schematic representation of the geometric relationships of a locking device.

That in the Fig. 1 and 2 The exclusively hand-operated strapping device 1 shown has a housing 2 which surrounds the mechanism of the strapping device and on which a handle 3 for handling the device is formed. The strapping device is also provided with a base plate 4, the underside of which is provided for arrangement on an object to be packaged. All functional units of the strapping device 1 are fastened on the base plate 4 and on the carrier of the strapping device (not shown in detail) which is connected to the base plate.

With the strapping device 1 an in Fig. 1 Loop (not shown) of a plastic tape B, for example made of polypropylene (PP) or polyester (PET), which was previously placed around the object to be packaged, can be tensioned by means of a tensioning device 6 of the strapping device. For this purpose, the tensioning device has a tensioning wheel 7 with which the band B can be gripped for a tensioning process. The tensioning wheel 7 is arranged on a pivotable rocker 8 which can be pivoted about a rocker pivot axis 8a. The tensioning wheel 7, which is arranged with its axis of rotation at a distance from the rocker pivot axis 8a, can be transferred into a second end position by a pivoting movement of the rocker 8 about the rocker pivot axis 8a from an end position at a distance from a preferably curved clamping plate 9 attached to the base plate 4 the tensioning wheel 7 is pressed against the tensioning plate 9. By means of a corresponding motor-driven movement in the opposite direction of rotation about the rocker pivot axis 8a, the tensioning wheel 7 can be removed from the tensioning plate 9 and pivoted back into its starting position, whereby the tape located between the tensioning wheel 7 and the tensioning plate 9 is released for removal.

When the tensioning device shown is in use, there are two layers of the strap between the tensioning wheel 7 and the tensioning plate and are pressed against the tensioning plate by the tensioning wheel 7. By rotating the tensioning wheel 7, it is then possible to provide the tape loop with a tape tension that is sufficiently high for the packaging purpose. The tensioning process and the tensioning device and rocker 8, which are advantageously designed for this purpose, are explained in more detail below.

The two layers can then be welded in a manner known per se by means of the friction welding device 12 of the strapping device at a point on the tape loop at which two layers of the tape lie one above the other. This allows the tape loop to be closed permanently. In the example shown here, the friction welding and cutting device 12 is driven by the same only one motor M of the strapping device, with which all other motor-driven movements are also carried out. For this purpose, in a manner known per se, in the transmission direction from the motor M to the points at which the motorized drive movement is provided a freewheel, not shown in detail, which causes the drive movement in the respective drive direction of rotation to the corresponding functional unit of the Strapping device is transmitted and no transmission takes place in the respective other drive direction of rotation of the motor provided for this purpose.

For this purpose, the friction welding device 12 is provided with a welding shoe 13, shown only in a highly schematic manner, which is transferred by means of a transfer device 14 from a rest position at a distance from the band to a welding position in which the welding shoe is pressed against the band. The welding shoe that is pressed onto the strapping band by mechanical pressure and the simultaneous oscillating movement of the welding shoe at a predetermined frequency melts the two layers of the strapping band. The locally plasticized or melted areas of the band B flow into one another and after the band B has cooled down, a connection is created between the two band layers. If necessary, the band loop can then be separated from a supply roll of the band by means of a cutting device, not shown in detail, of the strapping device 1.

The infeed of the tensioning wheel 7 in the direction of the tensioning plate 9, the rotary drive of the tensioning wheel 7 around the tensioning axis 6a, the lifting of the tensioning wheel from the tensioning plate, the infeed of the friction welding device 12 by means of the transfer device 14 of the friction welding device 12 as well as the use of the friction welding device 12 per se and the actuation of the cutting device are carried out using only one common electric motor M, the provides a drive movement for each of these components of the strapping device. To power the motor M, an exchangeable and, in particular, removable accumulator 15, which is used to store electrical energy, is arranged on the strapping tool. The supply of other external auxiliary energy, such as compressed air or other electricity, can be provided, but is carried out in the strapping device according to FIGS Fig. 1 and 2 Not.

As in Fig. 4 is shown, it is provided in the strapping device to tap its drive movement either for the tensioning device 6 or for the friction welding device 12 at two points on the drive shaft of the motor M. For this purpose, the motor M can be operated in either of the two directions of rotation. The transfer of the drive movement to the clamping device 6 or to the friction welding device 12 is changed automatically by a freewheel arranged on the drive shaft of the motor M (and not shown in detail) depending on the direction of rotation of the drive shaft of the motor. The drive movement is transmitted to the clamping device 6 in one direction of rotation of the drive shaft. Because of the freewheeling mechanism, the friction welding device 12 does not experience any drive movement. In the other direction of rotation, the clamping device 6 is without drive movement and the friction welding device 12 is driven. Any manual switching operations are not required to change the direction of transmission of the motorized drive movement. Such freewheels are already known in connection with strapping devices, which is why they will not be discussed in more detail.

As in the Fig. 4 is shown, the motorized transmission of the drive movement to the friction welding device 12 and transfer device 14 takes place by suitable means. This can be, for example, a toothed belt drive with an annularly closed toothed belt that is guided over two toothed wheels. One of the two gears is arranged on the drive shaft of the electric motor M, the other belongs to a transmission of the friction welding device 12, with which the motorized drive movement of both the transfer device 14 and the welding shoe 13 of the Reibschwelsseinrichtung 12 moved. The welding shoe, which is pressed onto two superimposed layers of the strapping band, can thereby be set in an oscillating movement with a predetermined frequency and amplitude, with which the two band layers are locally melted in the area of the welding shoe and then welded to one another through the subsequent cooling.

On the drive shaft of the motor, seen from the motor M, behind the toothed belt drive to the welding device, there is a bevel gear 19, which also belongs to a bevel gear of the clamping device, as does a second bevel gear 20 with which it meshes. On the same shaft on which the second bevel gear 20 is arranged there is also a first gear 21 of a further toothed belt drive 22, which is also guided via a second gear 23. The first gear 21 of the toothed belt drive 22 is arranged on the shaft 24 in a rotationally fixed manner.

The rocker 8 of the strapping device is pushed onto the other end of the shaft 24 and is part of the tensioning device 6 and carries the tensioning wheel 7 as well as a gear upstream of the tensioning wheel 7, here a planetary gear 26, for which purpose suitable bearings can be provided on the rocker 8 . The rocker 8 is pushed onto the shaft 24 in such a way that it is arranged and supported so that it can pivot about the longitudinal axis of the shaft 8. The longitudinal axis of the shaft 24 is thus at the same time the rocker pivot axis 8a about which the rocker 8 can be pivoted.

The planetary gear 26 can be designed as a single or multi-stage planetary gear, in particular as a two- or three-stage planetary gear. An input-side externally toothed sun gear 30 belonging to the planetary gear 26 projects from an end face of the gear wheel 23 facing the tensioning wheel 7, the axis of rotation of which is identical to the axis of rotation 6a of the input-side gear wheel 23. On a shaft of the gear 23, on which the sun gear 30 is also formed, there is a freewheel 45 which allows only one direction of rotation of the sun gear 30, namely the direction of rotation that is provided for driving the tensioning wheel. The sun gear 30 is passed through a ring gear 27 and through a central recess of a planet carrier 25, which are also part of the planetary gear 26. Seen from the input side of the planetary gear, the planet carrier 25 is on the axis of the planetary gear 26, the corresponding to the clamping axis 6a, arranged behind the ring gear 27. The planet carrier could also be designed in such a way that it represents a clamping, coupling or spur gear.

The ring gear 27 has on its outer circumference a cam 27c which is in engagement with a support 46 fastened to the base plate 4 of the strapping device. The internally toothed ring gear 27 is supported here in such a way that the cam 27c can execute slight relative movements within its engagement in the support 46, for example in a recess 46a of the support. The ring gear 27 also has an annular shoulder 27a on which a roller bearing 28 for supporting the planetary gear 26 is arranged.

The planetary carrier 25, the axis of which is aligned with the clamping axis 6a, is in engagement with its three planetary gears 25b with an internal toothing of the input-side ring gear 27 of the planetary gear 26. The planetary gears 25b of the planetary carrier 25 are also in engagement with the sun gear 30, of which one Record drive movement and can transmit to the ring gear 27 and correspondingly reduced. With a rotationally fixed arrangement of the planetary carrier 25, a rotational movement of the sun gear 30 can thus be converted into a rotational movement of the ring gear 27. A first clamp 29 of a locking device is designed as a pivotable cam which can be brought into contact with a clamping surface 25a on the outer circumference of the planet carrier 25 or pivoted away from it at a distance. The cam is arranged in such a way that when the cam comes into contact with the clamping surface 25a, the clamping effect is further intensified by a rotation of the planetary carrier 25 on the input side in the direction of rotation provided for the planetary carrier 25. By moving the cam onto the clamping surface 25a on the basis of a corresponding switching process, the planet carrier 25 can be blocked against rotation. By likewise a switching process, the cam 29 can be removed from the clamping surface 25a and the planet carrier 25 can thus be released for rotational movements. The switching process can trigger a pivoting movement of the terminal 29 about a switching axis 143, which is triggered by pressing a button 44.

The sun gear 30 is also arranged in the area of the axis of rotation 31 of a ring gear 32, the non-toothed outer surface 32a of which is assigned to a second clamp 33. The axis of rotation 31 is identical to or is aligned with the clamping axis 6a. The clamp 33 interacting with the outer surface 32a can in principle be designed in the same way as the first clamp 29 as a switchable cam that can be moved between two end positions, the ring gear 32 being blocked against rotation in one position and for rotational movements in the other position is released. Furthermore, an internal toothing of the ring gear 32 is in engagement with three planet gears 34, which are mounted on the end face of the following planet carrier 35 facing the ring gear 32. The planet gears 34 of the planet carrier 35 are also in engagement with the sun gear 30 of the input-side gear 23, which protrudes into the ring gear 32.

The locking device is designed in such a way that one and only one of the wheels 25, 32 is always clamped against rotation and the other wheel 25, 32 is free for rotational movements of the gear 23 and the sun gear 30 either leads to a rotation of the planet carrier 35 about the clamping axis 6a and rotation axis 31 due to a movement of the planet gears 34 in the internal toothing of the ring gear 32. Or the rotation of the sun gear 30 leads, depending on the positions of the locking device, to a rotation of the ring gear 32. If the planet carrier 25 is not clamped by the locking device, the rotating sun gear takes the planet gears 25b with it in such a way that the planet carrier 25 rotates and the ring gear 27 remains stationary. If, on the other hand, the ring gear 32 is not clamped, a rotation of the sun gear 30 leads to an entrainment of the planet gears 34, which in turn set the ring gear 32 in a rotational movement. Since the resistance to rotation in the further course of the planetary gear 26 towards the tensioning wheel 7 is greater than the torque to be overcome in order to set the ring gear 32 in rotation, the ring gear 32 in particular rotates and the tensioning wheel 7 rotates at least substantially Not.

On the other end face of the planetary carrier 35 facing the tensioning wheel 7, a further sun wheel 36, which has planetary gears, is non-rotatably arranged on the latter 41 of another planet carrier 42 meshes. A further sun gear 43 directed towards the tensioning wheel 7 and connected in a rotationally fixed manner to the planet carrier 42 is passed through a recess in the further planet carrier 37, which is designed as a ring gear. The sun gear 43 is in meshing engagement with the planet gears 38 of the further planet carrier 37 facing the tensioning wheel 7. The planet gears 38 of the second planet carrier 37 again mesh with an internal toothing of the tensioning wheel 7 and drive the latter to rotate about the tensioning axis 6a. This rotational movement of the tensioning wheel 7, which is provided with fine teeth (not shown) on its outer circumferential surface, is used to grasp the tape B with the circumferential surface and to pull back the tape of the tape loop, whereby a tape tension in the tape loop is increased.

The third planet carrier 37 has on its outer surface a shoulder 37a which can be brought into contact against a stop element 39 by a rotational movement. The stop element 39 itself is not fixed on the rocker but on the base plate 4 or some other carrier which does not take part in the pivoting movement of the rocker 8. The stop element 39 is thus stationary with respect to the shoulder 37a.

In use when strapping packaged goods, the strapping device 1 behaves as follows: After a tape loop with a commercially available plastic strapping tape has been placed around the respective packaged goods, this is inserted into the strap strapping device in the area of the strap end, in which the strap loop is partially double-layered, and the The end of the strap is held in place in the strapping tool with a strap clamp (not shown). A section of the tape B directly adjoining the tape loop is placed in two layers over the tensioning plate 9 of the tensioning device 6. The rocker 8 with the tensioning wheel 7 and the upstream gear 26 is here in its upper end position, in which the tensioning wheel 7 is arranged at a distance (with its greatest intended distance) from the clamping plate 9, which results in the largest possible opening gap, which is a allows easy, comfortable and thus also quick insertion of the tape into the tensioning device. The rocker is then lowered onto a tensioning plate 9 opposite the tensioning wheel 7 and pressed against the band arranged between the tensioning plate 9 and the tensioning wheel 7. Both these

Transfer movement of the tensioning wheel as well as the level of the contact pressure exerted by the tensioning wheel on the belt at the beginning of the tensioning process can be generated by one or more pretensioned spring elements 44 (not shown). By pressing a button 10, the spring element can be released and the entire strapping process with its successively executed process sections "tensioning", "locking production", "cutting", releasing the tension from the strap in the area of the tensioning device, and "lifting the rocker" can be triggered, including no further intervention by the operator of the strapping tool has to be carried out.

After the tensioning wheel 7 has automatically moved from the open position to its tensioning position (see tensioning position in Fig. 10 and open position in Fig. 11 ), in which it rests on the belt B and presses on the tensioning plate 9 via the belt, the motorized drive movement is transmitted to the tensioning wheel 7. The second clamp 33 is now moved into its position in which it presses against the ring gear 32. The ring gear 32 is hereby arrested and locked against rotational movements. The first terminal 29, however, is still positioned at a distance from the planet carrier 25 on the input side and releases the ring gear 27 for rotational movements. The motor drive movement, which, due to the intended specific direction of rotation of the motor M, is transmitted via the bevel gear 19, 20, 21 to the second toothed belt drive 22 and thus to the gear 23, arrives from here in the sequence of the gear members mentioned below via the input-side gear 23 , the sun gear 30, the planet gears 34, the sun gear 36, the planet gears 41, the sun gear 43 and via the planet gears 38 on the tensioning wheel 7 Required with a correspondingly high torque - be driven in the predetermined direction of rotation.

In the "tensioning" operating state of the strapping device just described above, the driven tensioning wheel 7, which is in engagement with the band, results in a corresponding in the opposite direction on the tensioning wheel 7, depending on the resistance force that results from the band tension and acts as a reaction to the tensioning wheel 7 acting counterforce. This counterforce acts in the opposite direction of transmission as the motorized drive movement, on all of the Transmission of the drive movement involved gear members of the multi-stage planetary gear. If another type of gear than a single or multi-stage planetary gear is used, the counterforce resulting from the already applied belt tension and introduced into the respective gear via the contact with the tensioning wheel is available for use. This counterforce can be used to improve the process conditions, in particular the functional reliability, even when the belt tensions to be applied are high. In order to use this counterforce for the purpose described below, it would in principle be possible to use each of these gear members for this purpose, in particular to pick up and use the said counterforce on each of these gear members.

The planet carrier 37 is used for this. The planet carrier 37 is supported on the base plate 4 via the stop element 39, whereby the entire tensioning device 6 is pressed onto the belt around the rocker axis 8a in proportion to the resistance force (belt tension). The tensioning wheel 7 is thus pressed onto the belt B in proportion to the belt tension. The belt tension generated by the tensioning process is used to advantageously increase the pressing force of the tensioning wheel 7 on the belt B as the belt tension increases, which increases the risk of the tensioning wheel "slipping through" or slipping as the belt tension increases 7 can be counteracted during the tensioning process.

For this purpose, the planet carrier is formed with the engagement element 37a, which interacts with the stationary stop element 39. The engagement element, which is designed as a cam and is arranged on the outer circumference of the planet carrier and protruding essentially radially from the latter, is supported on the stop element 39. How, among other things Fig. 3 is apparent, the stationary stop element 39 is for this purpose in the area of the head end of the strapping device. The stop element 39 is located on one side, namely the head end, the clamping axis 6a and the rocker pivot axis 8a running essentially parallel to it on the other side of the clamping axis 6a. The rocker 8, on which the planet carrier 37 is arranged to be rotatable about the clamping axis 6a via a roller bearing, is also at least during the clamping process pivotable, ie not blocked against pivoting movements but released for this. In addition, the planet carrier 37 can be rotated about the clamping axis 6a during the clamping process. The belt tension generated in response to the tensioning process in belt B causes a force on the tensioning wheel 7 that is opposite to the direction of rotation of the tensioning wheel provided during the tensioning process that the planet carrier 37 is pressed with increased force against the belt in the direction of the clamping plate 9. The higher the belt tension already introduced into the belt, the higher the torque resulting therefrom and from the motor drive movement that continues to act on the tensioning wheel 7. This resulting torque is in turn proportional to the resulting pressing force acting on the belt B by the tensioning wheel 7, with which the belt B is pressed by the tensioning wheel 7 against the tensioning plate 9. A belt tension increasing from the motorized drive movement on the tensioning wheel 7 is therefore accompanied by an increasing pressing force of the tensioning device on the belt.

After the end of the tensioning process and the subsequent welding process to form a seal, as well as after a motor-driven cutting process by a cutting device (not shown) integrated into the strapping device, the tape should be able to be removed quickly and without complications from the strapping device. To achieve this, a motorized lifting movement of the tensioning wheel 7 out of the tensioning position is provided. For this purpose, the button is actuated and as long as the button 10 is actuated, the rocker also remains in the open position, in which a sufficient distance between the clamping plate 9 and the tensioning wheel 7 is created. Releasing button 10 closes the rocker, for example by spring force.

For this purpose, the operative connection between the electric motor M and the cutting wheel 7 is first released and an operative connection between the electric motor M and the rocker 8 is created. This is achieved by switching terminals 29, 33. The previously existing clamping of the ring gear 32 is canceled in that the second clamp 33 is removed from the outer surface 32a of the ring gear 32 is removed and this thereby releases the ring gear 32 for rotational movements. Essentially at the same time or immediately thereafter, the first clamp 29 is lowered onto the clamping surface 25a of the planet carrier 25 and brought into clamping contact therewith. As a result, the planetary carrier 25 on the input side is fixed and locked against a rotational movement about the clamping axis 6a, along which the entire planetary gear is located.

As a result, the tensioning wheel 7 can rotate freely in a drive-free manner and no longer has an operative connection to the electric motor M and to the sun wheel 30, which could transmit a drive movement. A drive movement of the electric motor M with the same direction of rotation as during the tensioning process is now used due to the blocking of the input-side planetary carrier 25 of the planetary gear so that the planetary gears 25b of the spur gear 25 drive the input-side ring gear 27 with them during their rotational movement. The input-side ring gear 27 thus executes a rotational movement due to the rotating planet gears 25b. The contact and support of the ring gear 27 on the support element 46 leads to a pivoting movement of the ring gear 27 about the rocker axis 8a. The input-side ring gear 27, which is also non-rotatably connected to the rocker 8 due to the clamping, takes the rocker 8 with it during this movement. This leads to a lifting of the rocker 8 and the tensioning device 6 including the tensioning wheel 7 attached to it stops and the rocker locks. As a result of the motorized lifting movement of the rocker 8 counter to the effective direction of the spring element 44, the spring element 44 is again provided with an increased prestressing force. The strapping band B can now be removed from the strapping device 1.

The strapping device is now ready for a subsequent new strapping, which can be done in the same way as the strapping described above. For the subsequent lowering of the rocker 8 after the introduction of a new section of the strapping band B into the strapping device 1, the spring element 44 must be released again, which can be done, for example, via an operable button on the strapping device. It will do this the one before pressed button 10 released. The spring force then pivots the rocker 8 in the reverse pivoting direction towards the tensioning plate and clamps the band with an initial pressure force between the tensioning wheel 7 and the tensioning plate 9 for the subsequent tensioning process. The pressure force, which is variable in the further course of the clamping process, increases as described.

In the Figures 5 to 9 An exemplary embodiment of a strapping device according to the invention is shown. In terms of its external appearance, this can also be the representation of Fig. 1 are equivalent to. The basic structure of this embodiment of the strapping device can also correspond to that of the example discussed above. Accordingly, only one motor M is used in this embodiment as well, which has the in Fig. 5 Not shown welding device 12 and separating device is provided on the one hand in one of the two directions of engine rotation and the clamping device 6 on the other hand in the other direction of engine rotation. The optional drive of either the welding device and cutting device on the one hand or the clamping device 6 on the other hand takes place via a freewheel and different directions of rotation of the motor M.

The embodiment also has a pivotable rocker 80 of the clamping device 86 that is motor-driven about a rocker pivot axis 80a. In contrast to the example discussed above, it is not the tensioning wheel 87 but the tensioning plate 89 that is arranged on the pivotable rocker 80, the rocker pivot axis 80a of which runs parallel to the tensioning axis 86a. The motorized drive movement with the direction of rotation, which is used for rotational movements about the clamping axis 86a, is also used in this exemplary embodiment for the pivoting movement of the rocker 80. In this embodiment too, the rocker pivot axis 80a runs essentially parallel to the tensioning axis 86a, about which the tensioning wheel is rotatably mounted. Behind a point at which the motorized drive movement is used for the welding device, the rotational movement of the motor is transmitted via a bevel gear pair 99, 100 to a planetary gear 106 and passed on from there to the tensioning wheel 87. With a freewheel 125 arranged on the shaft of an input-side sun gear 110, it is ensured that the input side of the Planetary gear 106 can only rotate in one direction of rotation. The planetary gear 106 is provided with gear elements which, as in the example described above, can be optionally locked by means of a locking device comprising two clamps 29, 33, whereby the drive movement can be transmitted either to the tensioning wheel 87 or to the rocker 80.

To open the tensioning device 86, the ring gear 107 is released via the locking device, ie the clamp 33 is not in clamping engagement with the ring gear 107. The tensioning wheel 87 can thereby rotate freely without an operative connection with the motor M. Any tape tension retroactive from the just preceding tensioning operation from the strapping B onto the tensioning wheel 87 is thereby released by the tensioning wheel 87 and the gear unit 106 connected upstream of the tensioning wheel. The spur gear, which is designed as a planetary carrier 105 and whose axis of rotation is aligned with the clamping axis 86a, that is to say the axis of rotation of the tensioning wheel 87, is blocked with the clamp 29. The motor drive movement transmitted from the bevel gear 100 to the input-side sun gear 110 cannot lead to a rotation of the planet carrier 105 but to rotational movements of the planet gears 105b of the planet carrier 105 due to the releasable rotational locking of the planet carrier 105 made by means of the clamp 29. The internal toothing of the ring gear 109, which meshes with these planetary gears 105b, sets the latter in rotation. As in particular in Fig. 7 As can be seen, an external toothing 109c of the ring gear 109 is in engagement with an external toothing 150c of a circular arc segment 150 which is arranged in a stationary manner on one end of a connecting shaft 151. The connecting axis 151a of the connecting shaft 151 runs parallel to the stationary clamping axis 86a of this exemplary embodiment. Instead of the two external gears 109c, 150c, the ring gear 109 could also be supported on a support element via a cam, in which case either the cam or the support element should neither be attached to the ring gear 109 nor designed to be movable and the other of the two elements should be arranged on the ring gear 109.

The rotational movement of the ring gear 109 and the engagement of the ring gear 109 in the circular arc segment 150 lead to a rotational movement of the connecting shaft 151 about the connecting axis 151a. A spur gear 152 arranged at the other end of the connecting shaft 151 engages an external toothing 117c of the planet carrier 117 and thereby transmits the rotational movement about the connecting axis 151a to the planet carrier 117. With respect to the clamping axis 86a, the connecting axis 151a is on one and the rocker pivot axis 80a on the other side of the tensioning axis 86a, the rocker pivot axis 80a being on the side of the head-side end of the strapping device.

The planet carrier 117 belongs to the drive train which is provided for the drive movement of the tensioning wheel 87. The operative connection of this drive train to the motor M is momentarily interrupted due to the switching position of the locking device described above. Thus, at the time of the method described above, there is no operative connection between the motor M and the tensioning wheel 87 in order to drive the latter. As a result of the rotational movement transmitted to the planet carrier 117, the planet carrier 117 rotates about the clamping axis 86a and takes along a driver 80c of the rocker 80 with a cam 117a arranged on its outer circumferential surface. The rocker 80, which is arcuate in relation to a plan view, rotates as a result and is opened.

The rocker 80, which is rotatably mounted about the rocker axis 80a and has approximately the shape of a curved section, is arranged with its lower free end below the tensioning wheel 87, so that the tensioning plate 89 arranged in the area of the free end of the rocker 80 are also arranged directly below the tensioning wheel 87 can. In order to arrange the clamping plate 89 at a distance from the tensioning wheel 87, the previously described motor-driven movement of the rocker 80 in the direction of rotation according to arrow 112 ( Fig. 6 ), by means of which the rocker 80 is opened as described and a distance between the tensioning wheel 87 and the tensioning plate 89 is increased. The opening movement can be limited by a stop. The motor-driven rocker 80 now allows the tensioned and closed strapping loop to be removed from the strapping device. After the finished strapping has been removed, the end of a new strapping loop can be inserted between the tensioning plate and the tensioning wheel for a subsequent tensioning process. Due to the restoring force of the spring element 124 which was previously tensioned during the opening movement, the rocker 80 can be attached to the The tensioning wheel is brought up and the belt is pressed against the tensioning wheel with the initial pressure required for the tensioning process. In order to use the spring force and thereby move the rocker 80 in the direction of rotation according to arrow 113 in the direction of the tensioning wheel 87, actuation of a button or other actuating element can be provided, by which the spring force is released to act on the rocker. It can also be a question of releasing the button 10.

To tension the strapping band B arranged between the tensioning wheel 87 and the tensioning plate 89, the ring gear 107 is clamped on its outer circumferential surface by means of the clamp 33 to prevent rotational movements. The planet carrier 105 is not clamped and can therefore rotate just like the connecting shaft 8. The motorized drive movement from the sun gear 30 to the planetary gear 106 arranged on the clamping axle 86a is transmitted through the planet carrier 105 and the ring gear 107 to the planet gears 114 of the second planet carrier 115 and the latter is set in rotation. One in the representation of Fig. 5 The sun gear, which cannot be seen, drives the planetary gears 121 of a further downstream stage of the planetary gear 106. The planet carrier 122 of this stage also rotates. The sun gear 123 of the last-mentioned stage is passed through the further planet carrier 117 and drives the planet gears 118 of this further stage, which in turn mesh with an internal toothing of the tensioning wheel 87. The tensioning wheel 87 is thus driven in the tensioning direction via the single or multi-stage planetary gear 106 and the inserted tape B is tensioned.

In the "tensioning" operating state described above, in which the tensioning wheel 87 is in engagement with the belt B, the belt tension creates a drag force acting from the belt B on the rotating tensioning wheel 87 in the form of a restoring torque. Their size is variable and proportional to the size of the applied belt tension. This resistance force acts in opposition to the motor drive torque that is present in the transmission elements involved in the transmission of the drive movement. In the exemplary embodiment, the planet carrier 117 is supported on the rocker 80 with a cam 117b, which has the function of a stop. The planet carrier 117, which rotates in a suitable direction of rotation due to the motorized drive movement, lies opposite with its cam 117b a driver 80b of the rocker and thereby rotates it in a movement according to arrow 113 ( Fig. 6 ) around the rocker axis 80a against the tensioning wheel. If necessary, a noticeable rotational movement about the rocker axis 80a is not actually carried out, but essentially only increases the torque about the rocker axis 80a. In both cases, however, the pressing force with which the rocker 80 presses the tensioning plate 89 or the belt against the tensioning wheel 87 is increased. This increase is usually not done in a single step. The increase in the pressing force of the rocker against the belt, which is ultimately due to the motorized drive movement and the already existing belt tension and which occurs through intervention in the tensioning gear 106, is proportional to the force present in the belt and as a resistance against maintaining and against a further increase in belt tension on the belt Point of engagement in the belt, from the belt on the tensioning plate 89 and on the tensioning wheel 87, a resistance or restoring force takes place. As long as the tensioning process increases the belt tension, the resistance force and thus the resulting pressure force also increase.

In the Figures 8 and 9 the end positions of the rocker 80 which are possible due to the pivotability of the rocker for opening and closing on the one hand and to increase the pressing force on the band on the other hand are shown. As in Fig. 8 is shown, the clamping plate 89 is in one of the two end positions due to a contact of the cam 117b of the planet carrier 117 with a contour of the driver 80b and a direction of rotation of the planet carrier clockwise (with reference to the illustration of Fig. 8 ) the rocker is rotated counterclockwise around its rocker pivot axis. The driver 80b and the cam 117b act like a lever which causes a counterclockwise torque about the rocker pivot axis 80a.

Fig. 9 shows the end position of the open rocker. Here the planet carrier 117 rotates in comparison to Fig. 8 in the opposite direction of rotation and thereby comes into abutment against the driver 80c of the rocker 80. The driver 80c is located in relation to the rocker pivot axis 80a and the other driver 80b on the other side of the rocker pivot axis 80a. In the position of use of the strapping device with a horizontal orientation of the base plate, the driver 80b is located above and the driver 80c below the rocker pivot axis 80a. As a result, the rocker swivels in the illustration of Fig. 9 clockwise and thereby creates a distance from the tensioning wheel 87.

Fig. 12 shows a perspective partial view of the clamping device of the embodiment, in which only one of the two clamps is shown. Here the clamp 33 is brought into contact with the flat and in cross-section essentially exactly circular circumferential surface 107b of the ring gear 107. In Fig. 13 a sectional view through the ring gear 107 and the clamp 33 is shown. By means of the clamp 33 of the locking device, the ring gear can either be clamped against rotational movements or released again. Each of the in the strapping devices according to Fig. 5-9 provided clamps can preferably be designed according to the locking device described here, but conventional locking devices are also possible. In the preferred clamping according to the invention, an at least approximately flat circular or arcuate circumferential surface of the wheel interacts with a pivotable clamping element or clamping body. The peripheral surface 107b of the preferred exemplary embodiment shown, which functions as a clamping surface, does not have any latching elements with which a clamping based on a positive engagement of a clamping element in a latching element or a latching recess is provided.

The clamping element 33 is mounted pivotably about the switching and pivot axis 143, the switching axis 143 of the clamping element 33 running parallel to the axis of rotation of the wheel 107 to be clamped. The switching axis 143 runs in the area of one end of the cam-shaped clamping element 33. In the area of the other end of the clamping element, an arcuate contact surface 33a is provided, which is provided for contact with the clamping surface 107b of the wheel to be clamped. Due to the circular shape of the clamping surface 109b and the curved shape of the contact surface 33a in the side view, when the clamping element 33 comes into contact with the circumferential surface 107b, an essentially linear contact occurs, this contact line being perpendicular to the plane of the drawing Fig. 13 runs.

How out Fig. 13 As can be seen, the clamping element 33 is arranged in relation to the wheel 107 to be clamped in such a way that the contact line of the contact surface 33a is at a distance 155 from its pivot axis 143 which is greater than the distance between the pivot axis 143 and the clamping surface 107b. As a result, when the clamping element 33 pivots from its release position into a clamping position, it already comes into contact with the clamping surface 107b at a point that is in front of a straight line 156 connecting the axis of rotation of the wheel 107 with the pivot axis 143 of the clamping element. With respect to the intended direction of rotation 157 of the wheel 107 to be clamped, the contact line is located in front of the (imaginary) connecting line 156. The rotation of the wheel 107 is braked and can only move slightly further. Due to a further rotation against the increasing clamping effect, the clamping effect further intensifies and thereby increasing wedging of the clamping element 33 against the wheel 107 Connection line 156 and presses against the clamping surface 107b. In an end position, which essentially already corresponds to the position of the first contact with the clamping element 33, the wheel 107 is clamped against the cam-shaped clamping element 33. Further movement is no longer possible even with an arbitrarily high torque.

In Fig. 14 the geometric relationships during clamping are shown. Here, too, the connecting line between the axis of rotation 86a of the wheel 107 and the pivot axis 143 is denoted by 156. The contact surface (circumference) of the wheel could be smooth or slightly structured. The radius of the wheel at the point of contact with the cam is designated as 158 and the pivot radius of the clamping element 33 at the point of contact is designated 155. The pivot radius 155 at the contact point forms an angle α with the connecting line 156, and the radius 158 of the wheel 107 forms an angle γ with the pivot radius 155 (in each case at the contact point). In the exemplary embodiment, the geometric relationships are designed such that in the clamping position in which the wheel 107 is blocked against rotational movements in the intended direction of rotation, the angle γ is at least approximately 155 °. In tests, it was also possible to achieve good results when an angle from a range from 130 ° to 170 °, in particular from 148 ° to 163 ° adjusts. The angle α should advantageously be greater than or equal to 7 °. In the exemplary embodiment it is 9 °. In other embodiments, it can also be selected from a range from 7 ° to 40 °.

In the preferred embodiments of the invention discussed here, if the wedge effect is strong enough, it is not absolutely necessary for the position of the cam to be held in its clamping position by an external measure. This arises from the fact that the wheel 107 can only be rotated in one direction of rotation and it is precisely this direction that is releasably blocked by the clamp 33. In preferred embodiments of the invention, the cam-shaped clamping element is held in position by the spring force of a spring element 159. For this purpose, the spring element 159 rests against the clamping element above the switching axis 143 and rotates or holds the clamping element 29 in its clamping position. In order to remove the clamping element from its clamping position, the spring force must be overcome with a switch 160. With the switch 160, both terminals 29 and 33 can be operated at the same time. Depending on the arrangement of the switch / button, the spring force can be overcome by pulling or pressing the switch and the ring gear 107 released from the terminal 33 and the planet carrier 105 locked. With the respective other movement of the switch / button, the spring force releases the clamp 29 and the planet carrier 105, while the clamp 33 locks the ring gear 107.

List of reference symbols

1 To ripening device 2 casing 3 Handle 4th Base plate 6th Clamping device 6a Clamping axis 7th Tensioning wheel 8th Seesaw 8a Rocker pivot axis 9 Clamping plate 10 button 12th Friction welding device 13th Welding shoe 14th Transfer facility 15th accumulator 19th Bevel gear 20th Bevel gear 21 gear 22nd Toothed belt drive 23 gear 24 wave 25th Planet carrier 25a Clamping surface 25b Planetary gears 26th transmission 27 Ring gear 27a paragraph 27c cam 28 roller bearing 29 first clamp 29a arcuate contact surface 30th Sun gear 31 Axis of rotation gear and tensioning wheel 32 Ring gear 32a Outside area 33 second clamp 34 Planetary gear 35 Planet carrier 36 Sun gear 37 Planet carrier 37a paragraph 38 Planetary gear 39 Stop element 40 arrow 41 Panetenrad 42 Planet carrier 43 Sun gear 44 Spring element (return spring) 45 Freewheel 46 Support 46a Recess 80 swiveling rocker 80a Rocker pivot axis 80b Carrier 80c Carrier 86 Clamping device 86a Clamping axis 87 Tensioning wheel 89 Clamping plate 99 Bevel gear 100 Bevel gear 105 Spur gear (planet carrier) 105b Planetary gear 106 transmission 107 Ring gear 107b Circumferential surface 109 Ring gear 109b Circumferential surface 109c External gearing 110 Sun gear 112 arrow 113 arrow 114 Planetary gears 115 Planet carrier 117 Planet carrier 117b Interlocking 117a cam 117b cam 117c Interlocking 118 Planetary gear 121 Planet wheel 122 Planet carrier 123 Sun gear 124 Spring element 125 Freewheel 143 Switching axis 150 Circular arc segment 150c Interlocking 151 Connecting shaft 151a Connection axis 155 Distance / swing radius 156 Connecting line 157 Direction of rotation 158 radius 159 Spring element 160 counter B. tape M. engine

Claims (15)

1. Strapping device for strapping packaged goods with a strap,
   said strapping device having a tensioning apparatus (86) for applying a strap tension to a loop of a strap, wherein the tensioning apparatus (86) is provided with a tensioning wheel (87) which is able to be driven in a motorized manner so as to rotate about a tensioning axis (86a) and is provided for engaging in the strap, the tensioning apparatus furthermore has a tensioning plate (89), wherein it is provided during a tensioning procedure carried out by the tensioning apparatus (86) that a single-ply or multi-ply portion of the strap is situated between the tensioning wheel (87) and the tensioning plate (89) and contacts the tensioning wheel (87) as well as the tensioning plate (89),
   the tensioning plate (89) is furthermore disposed on a rocker (80) which in a motorized manner is pivotable about a rocker axis so as to by way of a pivoting movement of the rocker (80) either increase or decrease a spacing between the tensioning wheel (87) and the tensioning plate (89), as well as having a connecting apparatus for, by means of a connecting element, such as a welding element, which is provided for locally heating the strap, generating a permanent connection, in particular a welded connection, on two regions of the loop of the strap that lie on top of one another, characterized in that
   while the motorized driving movement is being transmitted to the tensioning wheel (87), for as long as the tensioning wheel (87) engages with the strap, a driving movement by means of a transmission means (117) of the strapping device is transmitted to the rocker (80) which is pivotable during the duration of the tensioning procedure, wherein the driving movement is provided for exerting a torque on the rocker (80).
2. Strapping device according to Claim 1, characterized in that, during the tensioning procedure of the strap by means of the tensioning wheel (87) that engages in the strap and rotates counter to a strap tension, a counterforce which acts from the strap on the tensioning wheel (87) or on the tensioning plate (89) is utilized for increasing the contact pressure of the tensioning plate (89) in relation to the strap.
3. Strapping device according to Claim 2, characterized by an increase in the contact pressure, said increase taking place so as to be at least substantially proportional to the respective momentary strap tension.
4. Strapping device according to one of the preceding claims, characterized by only one motor (M), by way of the driving movements of which in identical rotating directions, both the tensioning wheel (87) for tensioning the strap is able to be set in rotation and the rocker (80) having the tensioning plate (89) disposed thereon is pivotable about the rocker axis, in particular so as to enlarge a spacing between the tensioning wheel (87) and the tensioning plate (89) by way of this pivoting movement.
5. Strapping device according to Claim 1, characterized by means for variably pressing the tensioning wheel (87) onto the strap independently of the strap tension.
6. Strapping device according to Claim 5, characterized in that the variable pressing of the tensioning wheel (87) against the strap independently of the strap tension takes place by virtue of a motorized driving movement.
7. Strapping device according to Claim 6, characterized in that the variable pressing independently of the strap tension takes place by way of the same motorized driving movement by way of which the tensioning wheel (87) is also driven for rotation.
8. Strapping device according to one of the preceding claims, said strapping device having a gearbox (106) for transmitting a driving movement in particular to the tensioning apparatus (86), the gearbox (106) to this end having at least one rotatable wheel (107) which is able to be locked by means of a blocking apparatus,
   characterized in that
   the blocking apparatus has at least one clamp (29, 33) which is pivotable about a pivot axis and is disposed so as to be spaced apart from the wheel (107) and which from a releasing position is pivotable to a blocking position in which said blocking apparatus comes to bear against a substantially flat circumferential clamping face (107b) of the wheel (107), wherein the clamp (29,33) has a pivoting radius (155) which is larger than a spacing of the pivot axis of the clamp (29, 33) from the circumferential clamping face (107b) of the wheel (107), and the rotating direction of the clamp (29, 33) about the pivot axis when transitioning from the releasing position to a clamping position runs in a sense of rotation which is counter to that of the wheel (107) to be clamped.
9. Strapping device according to Claim 8, characterized in that in the clamping position a pivoting radius of the clamp (29, 33) at a contact point of the clamp (29, 33) on the circumferential clamping face (107b) of the wheel (107) in relation to a connecting line between the pivot axis (143) and a rotation axis of the wheel (107) encloses an angle γ which is chosen from a range from 120° to 170°, preferably from a range from 140° to 165°, particularly preferably from a range from 149° to 162°, and most particularly preferably from a range from 152° to 158°.
10. Strapping device according to Claim 8 or 9, characterized in that in the clamping position the pivoting radius (155) of the clamp (29, 33) at the contact point of the clamp (29, 33) and the circumferential clamping face in relation to a connecting line (156) between the rotation axis of the wheel (107) and the pivot axis (143) of the clamp (29, 33) encloses an angle α which is chosen from a range from 5° to 25°, preferably from a range from 7° to 15°, and particularly preferably from 7° to 10°.
11. Strapping device according to one of preceding Claims 8 to 10, characterized in that the blocking apparatus is provided for clamping a wheel (107) of the tensioning apparatus (86).
12. Strapping device according to Claim 11, characterized in that the blocking apparatus for clamping a wheel (107) is brought to bear during the tensioning phase, and on which wheel the strap tension applied to the strap acts completely or partially.
13. Strapping device according to Claim 12, characterized in that the blocking apparatus is provided for releasing the clamping action previously performed, while the strap tension acts completely or partially on the clamped wheel (107).
14. Strapping device according to one of preceding Claims 1 to 7, characterized by a gearbox (106) of the tensioning apparatus (86) by way of which a motorized driving movement for the tensioning wheel (87) is negatively or positively geared, and which completely or partially is a component part of the transmission means (117) by way of which the force acting on the tensioning wheel (87) and resulting from the strap tension is transmitted from the strap to the rocker (80).
15. Strapping device according to one of preceding Claims 1 to 7, characterized in that the transmission means (117) constitute an operative connection between the tensioning wheel (87) and the rocker (80) and comprise a rotatably mounted gearbox element which during the tensioning procedure is operatively connected to the tensioning wheel (87).

Images