EP3696103A1 - Strapping device, in particular for steel strips - Google Patents

Abstract

The present invention relates to a strapping device for, in particular, steel straps (1). This is equipped with a clamping unit (3, 4) and a closer unit (5, 6, 7). In addition, a single motor, in particular an electric motor (8), acts on both the clamping unit (3, 4) and the closer unit (5, 6, 7). According to the invention, the tensioning unit (3, 4) and the closing unit (5, 6, 7) are each equipped with an alternating freewheel (10, 11).

Description

The invention relates to a strapping device for steel straps in particular, with a tensioning unit and a closer unit, and with a single motor, in particular an electric motor, which acts on both the tensioning unit and the closer unit.

Strapping devices for steel straps, in particular, are used, for example, to strap metal strap coils, steel girders, etc. For this purpose, the objects to be strapped are usually fed with a conveyor and strapped with the steel band. For this purpose, the steel belt is usually guided around the objects in question with the aid of a belt guide frame. The steel band in question is then tensioned with the aid of the tensioning unit and closed at the ends of the band to be connected using the closer unit. To do this, you can work with a closure sleeve pushed over the strap ends to be connected and pressed together with the strap ends to be connected. However, it is also possible to couple the relevant tape ends to one another via a sleeveless connection, as is the case with the prior art according to the generic type WO 2016/014167 A1 describes.

At this point, the possibility of designing a tensioning motor there and also a closer motor as a (single) motor is basically addressed. As a rule, however, two motors are used. The prior art, which is also generic, proceeds in a similar manner according to US 6,966,255 B1 in front.

The state of the art has basically proven itself. This is because a strapping device with a single motor and in particular an electric motor is initially and in principle characterized by its low weight. As a result, such a strapping device can in principle also be designed as a hand-held device. However, the previous solutions have a relatively complex mechanical structure and the change from the clamping function to the closer function is not easy to implement. This also applies when considering the further state of the art according to DE 10 2008 004 118 B4 .

The invention is based on the technical problem of developing such a strapping device, in particular for steel straps, in such a way that a structurally simple structure is realized and the change from the tensioning function to the closer function and vice versa can take place simply, precisely and intuitively.

To solve this technical problem, a generic strapping device within the scope of the invention is characterized in that the tensioning unit and the closer unit are each equipped with an alternately working freewheel.

In the context of the invention, both the tensioning unit and the closing unit are each equipped with a freewheel. The freewheel belonging to the clamping unit is called the clamping unit freewheel. In contrast, the freewheel of the closer unit is a closer unit freewheel. The two freewheels work alternately, i.e. either only the closer unit freewheel or only the clamping unit freewheel. In this context it is provided that the closer unit freewheel and the tensioning unit freewheel depending on the direction of rotation of the motor press either the clamping unit or the closer unit.

The invention is based on the knowledge that the single motor as the drive for the strapping device is typically designed as an electric motor. Of course, other motors are also conceivable in this context, such as a pneumatic motor, although not preferred. In fact, an electric motor typically used at this point is characterized in that in this way the strapping device can be operated entirely independently. Additional compressed air lines as with a pneumatic motor are not required. Because when using an electric motor, the design can be made in such a way that the electric motor is fed with the necessary electrical energy with the aid of one or more accumulators. Of course, wired solutions are in principle also covered by the invention. In this case, the electric motor is supplied with the required electrical energy via a power cable.

The accumulator in question or the plurality of accumulators can be detachably and exchangeably arranged and held in a housing of the strapping device. In this case, the battery in question can be recharged in an additional charging cradle, for example. But it is also possible to leave the accumulator firmly in the housing and charge it inductively. Either way, an electric motor is predestined as a motor for the strapping device for the applications described.

In general, the procedure is that the closer unit freewheel locks in a counterclockwise direction and the clamping unit freewheel locks in a clockwise direction, or vice versa. This means that the closer unit freewheel runs in Clockwise free, while the clamping unit freewheel freewheels counterclockwise, or vice versa. The invention is based on the knowledge that the electric motor typically used at this point rotates counterclockwise or clockwise and consequently transmits this respective rotary movement either to the clamping unit or the closer unit, specifically in the sense of an "either-or" link. The two freewheels ensure that. The electric motor can also work with the interposition of a gear on the clamping unit and the closer unit. With the help of the gear, the high-speed revolutions of the electric motor are usually reduced, that is, brought down to slow speed. This is done on the basis of the knowledge that both the tensioning process and the closing process of the mostly used steel belts do not require high speeds, but high torques.

In addition, the closing unit is usually acted upon on the output side of the tensioning unit with the interposition of a transmission means. The design is also made such that the transmission means works with the implementation of a reduction gear on the closer unit. That is, during operation of the closer unit and consequently a closing process of the belt ends to be connected, in particular the steel belt, there is, as it were, a double reduction of the high-speed rotary movements of the electric motor. On the one hand, the gearbox following the electric motor provides an initial reduction. On the other hand, the transmission means is provided between the closer unit and the gear, realizing a second reduction gear.

This second reduction gear as part of the transmission means is implemented as a rule in such a way that the flexible transmission means has two Gears is performed, which provide the desired reduction, consequently act as a reduction gear. A toothed belt or a chain, for example, can be used as the transmission means as the flexible transmission means. In this way, the invention takes into account the fact that particularly high torques must be made available for the operation of the closer unit. This is made available by the invention through the two reduction gears.

The closer unit is generally arranged in the axial direction of the electric motor and, if applicable, of the transmission. In contrast, the clamping unit is generally located perpendicular to the axial direction of the electric motor and, if applicable, of the gearbox. In this way, an overall compact structure is made available. The invention is based on the knowledge that the strapping band or steel band generally has to be guided through the strapping device in the axial direction or transversely to the axial direction of the electric motor and consequently has to be tensioned in this axial direction or transversely thereto. This is ensured by the clamping unit, which is mostly oriented perpendicular to the axial direction of the electric motor. The tensioning unit may also be arranged perpendicular to the transmission. Since, furthermore, the two belt ends to be connected are arranged in the axial direction of the electric motor and, if applicable, of the gearbox, this explains why the closer unit is also provided and oriented in this axial direction. As a result, the closer unit, which is usually equipped with two closing tongs, can ensure the desired closing of the strap ends to be connected. The two locking pliers each work transversely to the longitudinal extension of the band. The closure can take place directly, for example, by crimping the ends of the strap to be connected or by a closure sleeve pushed and squeezed over the two strap ends to be connected.

In addition to the two locking tongs, the closer unit is also equipped with at least one cam for acting on the two locking tongs. In addition, the closer unit can be designed as a whole as an exchangeable closer module that can be decoupled from the drive and coupled to the drive, or it can constitute a component of such a closer module. This makes it possible to remove the closer module or the closer unit itself from the drive and, for example, to revise, retool or service it. For this purpose, the closer module can be detachably connected as a whole to an axial arm. In contrast, the motor including the optional gearbox runs parallel to the axial arm and is connected to the axial arm with a mounting flange.

In contrast, the clamping unit is usually equipped with a worm wheel. The worm wheel in turn meshes with an output worm on an output shaft of the motor or transmission. In this way, the worm wheel can be directly and automatically oriented perpendicularly in comparison to the output worm and thus the output shaft of the motor, as is the case for the clamping unit as a whole, which is oriented perpendicular to the axial direction of the electric motor and possibly the transmission.

The result is a strapping device for steel straps, in particular, which is characterized by a compact and structurally simple structure. This is because the use of the alternating freewheels ensures that, depending on the direction of rotation of the motor or electric motor, either only the clamping unit or the closer unit is acted upon by the electric motor in question. This allows you to change the direction of rotation of the electric motor between a clamping process and a Differentiate and switch over the closing process, without the need for complicated mechanics or kinematics. Since one of the two freewheels is automatically blocked during such a switchover process, it is ensured that either the steel belt in question is tensioned with the aid of the tensioning unit or that the belt ends to be connected are crimped or squeezed after the tensioning process has been completed using the closer unit.

The change in the direction of rotation of the electric motor can optionally be carried out by an operator. But it is also possible to have an automatic switchover. In this case, for example, the tension in the steel strip or generally in the strapping can be measured using a sensor or by measuring the current consumption of the electric motor during the tensioning process. In this regard, it is particularly advantageous if the power consumption of the advantageously used electric motor is evaluated. At this point, a certain threshold for the power consumption and thus the clamping force can be used to automatically switch from the clamping process to the closing process. This is where the main advantages can be seen.

Fig. 1

Die erfindungsgemäße Umreifungsvorrichtung in einer ersten perspektivischen Ansicht,

Fig. 2

den Gegenstand nach Fig. 1 aus einer anderen Blickrichtung und

Fig. 3

den Gegenstand nach den Figuren 1 und 2 mit Verschließermodul sowie entfernter Verließereinheit und

Fig. 4

eine alternative Ausführungsform nach Fig. 1.

The invention is explained in more detail below with the aid of a drawing showing only one exemplary embodiment; show it:

Fig. 1

The strapping device according to the invention in a first perspective view,

Fig. 2

the subject Fig. 1 from a different perspective and

Fig. 3

the subject after the Figures 1 and 2 with closer module and removed closer unit and

Fig. 4

an alternative embodiment according to Fig. 1 .

The figures show a strapping device which is particularly suitable and provided for strapping objects with the aid of one or more steel straps 1. For this purpose, the relevant and primarily in the Fig. 2 The steel band 1 shown is looped around the objects to be strapped, tensioned with the aid of the strapping device shown and the ends of the steel band 1 are subsequently closed. This can be done using an in the Fig. 2 shown closure sleeve 2 happen, which is pushed over the band ends to be connected of the steel band 1 and pressed or crimped with them. In principle, the band ends of the steel band 1 can also be pressed together without a sleeve, but this is not shown.

According to the exemplary embodiment, the strapping device has a tensioning unit 3, 4 and a closer unit 5, 6, 7. In addition, a single motor 8 is implemented which, according to the exemplary embodiment, is an electric motor 8. The electric motor 8 is used with the interposition of a gear 9 on the one hand to act on the clamping unit 3, 4 and on the other hand the closing unit 5, 6, 7, alternately and alternately, as will be described in more detail below.

According to the invention, the tensioning unit 3, 4 and the closer unit 5, 6, 7 are each equipped with an alternately working freewheel 10, 11. In fact, a tensioning unit freewheel 10 on the one hand and a closer unit freewheel 11 on the other hand are implemented. Depending on the direction of rotation of the electric motor 8, both freewheels 10, 11 act on either the clamping unit 3, 4 or the closer unit 5, 6, 7. According to the exemplary embodiment, the design is so affected that the closer unit freewheel 11 in the Fig. 2 Closing process shown or the closing unit 5, 6, 7 locks counterclockwise. In contrast, a clockwise lock is provided for the tensioning unit freewheel 10. Consequently, the closer unit freewheel 11 runs free in clockwise direction, while the tension unit freewheel 10 has a freewheel in the counterclockwise direction.

The closing unit 5, 6, 7 is acted upon on the output side of the clamping unit 3, 4 with the interposition of a transmission means 12. The transmission means 12 actually works with the implementation of a reduction gear 13, 14 on the closer unit 5, 6, 7. According to the exemplary embodiment, the reduction gear 13, 14 is two gears 13, 14 over which the flexible transmission means 12 designed as a toothed belt is guided becomes. The reduction of the reduction gear 13, 14 implemented at this point results from the fact that a first gear 13 connected to the electric motor 8 and the interposed gear 9 on the drive side is equipped with a smaller number of teeth than a second gear 14, which is equipped with the aid of the transmission means or the toothed belt 12 is set up to act on the closer unit 5, 6, 7. In fact, a reduction i = 1 or less is usually used at this point.

On the basis of a comparative consideration of the figures, it can be seen that the closer unit 5, 6, 7 is arranged in the axial direction of the electric motor 8 and, if applicable, of the transmission 9. In fact, a total of an axial arm 15 is implemented in this axial direction. In comparison to this, the clamping unit 3, 4 is oriented perpendicular to the axial direction of the electric motor 8 including the gear 9 or the axial boom 15. For this purpose, a mounting flange 16 is provided according to the embodiment, with the Help the motor 8 including the downstream gear 9 is connected parallel to the axial arm 15 with this. In principle, the axial arm 15 and the fastening flange 16 can also form a structural unit or a single component.

Based on Fig. 3 it can be seen that the closer unit 5, 6, 7 including reduction gears 13, 14 and flexible transmission means or toothed belt 12 as a whole as closer module 5, 6, 7; 12; 13, 14 is formed. For this purpose, the closer module 5, 6, 7; 12; 13, 14 equipped with the axial arm 15. The axial boom 15 can be designed to be detachable and coupled and uncoupled from a link 17. As a result, the closer unit 5, 6, 7, including the link 17 that supports and supports it, can be removed from the axial arm 15, the motor 8 including the gear 9 and the reduction gear 13, 14 as well as the transmission means 12 and can be coupled to it again if necessary.

In the Fig. 4 a variant is shown in which the reduction gear 13, 14 is designed as a worm gear or contains one. In this case, a gear 13 connected to the transmission 9 may still be implemented, which works with the aid of the transmission means or toothed belt 12 on the further gear 14, both gears 13, 14 in this case transversely to the axial direction of the electric motor 8 and the downstream gear 9 are arranged. The reduction gear 13, 14 implemented in this way then in turn works via a worm shaft on a further gear, with the aid of which the closer unit 5, 6, 7 is then acted as a whole. In this case, too, the closer unit 5, 6, 7, including the link 17 that supports and supports it, can be removed from the axial arm 15 and coupled with it again if necessary. As a result, the closer unit 5, 6, 7 are removed from the motor 8, including the gear 9 and the reduction gear 13, 14 connected to the axial boom 15, and coupled with it again if necessary.

The way it works is as follows. Based on the Fig. 1 the clamping drive or the clamping function is shown here. Corresponding to this is a rotational movement of an output shaft of the electric motor 8 and consequently also of the downstream gear 9 in the clockwise direction indicated here. The clockwise rotation of the electric motor 8 and of the downstream gear 9 is transmitted to a worm wheel 4 via an output worm 3 fastened on the output shaft. For this purpose, the output worm 3 rotates on the output shaft oriented in the axial direction. In contrast, the worm wheel 4 is oriented vertically and thereby executes a rotary movement likewise in a clockwise direction. Since the associated tensioning unit freewheel 10 locks in a clockwise direction, the rotational movement of the worm wheel 4 is transmitted to one or more drive rollers, so that the tensioning unit 3, 4 as a whole ensures that the steel band 1 around the objects to be strapped is tensioned. This corresponds to one in the Fig. 2 indicated movement of the steel strip 1 in the axial direction.

This clamping process is continued until a sensor determines the required and achieved clamping force. According to the embodiment and the illustration in FIG Fig. 1 In the following, the design is made such that the power consumption of the electric motor 8 is measured with the aid of a control unit 18 indicated there. If the power consumption of the electric motor 8 exceeds a specific threshold preset in the control unit 18, this is interpreted as a sufficient clamping force. As a result, the control unit 18 ensures that of the previously described and in the Fig. 1 shown clamping function on the closer function after Fig. 2 is switched.

In contrast to the tensioning unit freewheel 10, which is locked in the indicated clockwise direction and consequently ensures the described tensioning process of the steel strip 1, the closer unit freewheel 11 runs free during this process. Because the clockwise rotation of the output shaft of the electric motor 8 including the downstream gear 9 is transmitted via the first gear 13 to the second gear 14 with the interposition of the toothed belt 12. The second gear wheel 14, which is equipped with the closer unit freewheel 11, also rotates clockwise. Since the closer unit freewheel 11 freewheels clockwise, two are in the Fig. 2 The locking pliers 7 shown and providing for the locking process of the steel strip 1 as part of the locking unit 5, 6, 7 are not acted upon.

If the desired clamping force is reached and the value for the current consumption of the electric motor 8 exceeds the threshold mentioned above, the control unit 18 ensures that the electric motor 8 is switched over in terms of its direction of rotation. As a result of this, the electric motor 8 accordingly performs a counterclockwise rotation, as in the associated one Fig. 2 is shown. Now the electric motor 8 including the gear 9 ensures that the closer unit 5, 6, 7 is controlled. Because the one in the Fig. 2 The counterclockwise rotation of the electric motor 8 shown on the output side of the transmission 9 also causes the output worm 3 arranged on the output shaft to rotate counterclockwise. This has the consequence that the tensioning unit freewheel 10 rotates counterclockwise and is thus free-running. The one or more rollers or tensioning wheels are consequently no longer acted upon.

At the same time, the counterclockwise rotation of the electric motor 8 including the downstream gear 9 ensures that the closer unit freewheel 11 rotates counterclockwise and is consequently blocked. As a result, rotations of the second gear 14 are transmitted to a cam 5 as part of the closer unit 5, 6, 7. The cam 5 for its part works on an interposed lever chain 6, which overall ensures that the previously mentioned locking tongs 7 are moved towards one another and are closed transversely to the longitudinal extension of the steel strip 1. As a result, the Fig. 2 indicated closure sleeve 2 is pressed onto the band ends of the steel band 1 to be connected. As a result, the tape ends are permanently plastically deformed and coupled to one another. During this process, on the one hand, the rotary movements of the high-speed electric motor 8 are reduced with the aid of the gear 9 and, on the other hand, there is a further reduction in the second reduction gear 13, 14. In this way, the electric motor 8 can apply considerable torques to the locking sleeve 2 are exercised for pressing.

The electric motor 8 is coupled as a whole to an accumulator, not shown, which serves to supply it with electrical energy. The accumulator may be arranged in a detachable or fixed manner in a housing. The strapping device shown can work as a handheld device or as a stationary device.

In the Fig. 3 Finally, the possibility of being able to remove the closer unit 5, 6, 7 including the link 17 from the axial boom 15 is illustrated. As a result, the link 17 with the cam 5 mounted thereon, the lifting chain 6 and the two locking tongs 7 can be exchanged and revised if necessary. The closer unit 5, 6, 7 as part of the closer module 5, 6, 7; 12; 13, 14 is thus designed overall as a module that can be decoupled from the motor 8 and coupled to the motor 8 as well as being exchangeable.

Claims (15)

Strapping device for steel straps (1) in particular, with a tensioning unit (3, 4) and a closer unit (5, 6, 7), and with a single motor, in particular an electric motor (8), which controls both the tensioning unit (3, 4) and the applied to the closer unit (5, 6, 7), characterized in that the clamping unit (3, 4) and the closer unit (5, 6, 7) are each equipped with an alternating free wheel (10, 11). Device according to claim 1, characterized in that a closer unit freewheel (11) and a clamping unit freewheel (10) are provided which, depending on the direction of rotation of the motor, either the clamping unit (3, 4) or the closer unit (5, 6, 7 ) apply. Device according to Claim 1 or 2, characterized in that the closer unit freewheel (11) locks in the counterclockwise direction and the clamping unit freewheel (10) locks in the clockwise direction, or vice versa. Device according to one of Claims 1 to 3, characterized in that the motor works with the interposition of a gear (9) on the clamping unit (3, 4) and the closer unit (5, 6, 7). Device according to one of Claims 1 to 4, characterized in that the closing unit (5, 6, 7) is acted upon on the output side of the tensioning unit (3, 4) with the interposition of a transmission means (12). Device according to Claim 5, characterized in that the transmission means (12) is designed as a flexible transmission means, for example as a toothed belt or chain. Device according to Claim 5 or 6, characterized in that the transmission means (12) works on the closer unit (5, 6, 7) by implementing a reduction gear (13, 14). Device according to one of Claims 1 to 7, characterized in that the closer unit (5, 6, 7) is arranged in the axial direction of the electric motor (8) and, if appropriate, of the gearbox (9). Device according to one of Claims 1 to 8, characterized in that the tensioning unit (3, 4) is oriented perpendicular to the axial direction of the electric motor (8) and, if appropriate, of the gear unit (9). Device according to one of Claims 1 to 9, characterized in that the tensioning unit (3, 4) is equipped with a worm wheel (4) which meshes with an output worm (3) on an output shaft of the motor or transmission (9). Device according to one of Claims 1 to 10, characterized in that the closer unit (5, 6, 7) is equipped with two closing tongs (7). Device according to claim 11, characterized in that the closer unit (5, 6, 7) has at least one cam (5) for acting on the two closing tongs (7). Device according to one of Claims 1 to 12, characterized in that at least the closing unit (5, 6, 7) is designed as a module which can be decoupled from the motor (8) and coupled to the motor (8) and is exchangeable. Device according to Claim 13, characterized in that the motor (8) including the reduction gear (13, 14) and transmission means (12) is connected to an axial arm (15). Device according to Claim 14, characterized in that the motor, including the optional gear (9), runs parallel to the axial boom (15) and is connected to the latter with a fastening flange (16).

Images