Strapping device

Abstract

A strapping device (100) for strapping one or more articles with a strap is described, comprising a tensioning apparatus (1) for tensioning the strap around the one or more articles, a joining apparatus (2) for joining two overlapping portions of the strap, a first actuating device (5.1) operatively connected to the tensioning apparatus (1), a second actuating device (5.2) operatively connected to the joining apparatus (2), an actuating drive (4), a first clutch (3.1) configured to couple the tensioning apparatus (1) with the actuating drive (4) and a second clutch (3.2) configured to couple the joining apparatus (2) with the actuating drive (4), wherein the first actuating device (5.1) is configured to execute on the tensioning apparatus (1) an actuating motion generated by a first drive motion of the actuating drive (4) via the coupling of the first clutch (3.1), and the second actuating device (5.2) is configured to execute on the joining apparatus (2) an actuating motion generated by a second drive motion of the actuating drive (4) via the coupling of the second clutch (3.2) .

Description

Field of the invention

[0001] The present invention relates to a strapping device for strapping one or more articles with a strap.Background of the invention

[0002] Strapping devices are used for packing various articles by placing a strap around the articles such that two portions of the strap overlap each other by forming a loop around the articles. The overlapping portions of the strap are connected to each other by a strapping device which is applied to tension the strap and to join the overlapping portions of the strap. For tensioning the strap, a tensioning apparatus with a tensioning wheel is used which can be lowered onto the strap in order to contact the strap for tensioning and raised from the strap in order to release or to introduce the strap. Various joining techniques can be used for joining the overlapping portion, such as for example welding, crimping, gluing etc., the specific technique depending on the articles to be strapped and / or the material of the strap. For joining the overlapping portions of the strap, a welding crimper can be lowered onto the strap in order to join the overlapping portions of the strap and raised from the strap in order to release or to introduce the strap.

[0003] For example, DE 10 2011 122 157 A1 describes a strapping apparatus for strapping a tensioning strap around a packaged item, said apparatus including a frictional wheel which works against a support for tightening the named tensioning strap, wherein the frictional wheel is operatively connected to a drive and is liftable from the support by means of a pivot lever. The pivot lever arm is provided with an interrupting element in order to interrupt the path of action between the frictional wheel and the drive. A gear unit is provided in the path of action between the frictional wheel and the drive and the interrupting element acts on an element of said gear unit. The gear unit is arranged in or on a bearing block, the bearing block being tiltable by means of the pivot lever. As a result of the tilting of the bearing block, the gear unit can be tilted simultaneously in this case and the frictional wheel which is connected thereto can also be lifted off at the same time. An elastic means, for example a spring or a helical spring, is arranged between the pivot lever and the bearing block. The elastic means has the effect of pivoting the pivot lever back automatically in the case of its non-actuation.Summary of the invention

[0004] While packing articles, it is desired to provide a strapping device where the tensioning apparatus and the joining apparatus can be operated in a precise and an efficient manner.

[0005] It is therefore an object of the invention to provide a strapping device which at least partially improves the prior art and avoids at least part of the disadvantages of the prior art.

[0006] According to the present invention, this object is achieved by the features of the independent claims. In addition, further advantageous embodiments follow from the dependent claims and the description as well as the figures.

[0007] According to an aspect of the invention, this object is particularly achieved by a strapping device for strapping one or more articles with a strap, comprising a tensioning apparatus for tensioning the strap around the one or more articles, a joining apparatus for joining two overlapping portions of the strap, a first actuating device operatively connected to the tensioning apparatus, a second actuating device operatively connected to the joining apparatus, an actuating drive, a first clutch configured to couple the tensioning apparatus with the actuating drive and a second clutch configured to couple the joining apparatus with the actuating drive, wherein the first actuating device is configured to execute on the tensioning apparatus an actuating motion generated by a first drive motion of the actuating drive via the coupling of the first clutch, and the second actuating device is configured to execute on the joining apparatus an actuating motion generated by a second drive motion of the actuating drive via the coupling of the second clutch.

[0008] By providing a first actuating device for the tensioning apparatus and a second actuating device for the joining apparatus, the strapping device can be optimized for the respective actuating motions required for the tensioning apparatus and the joining apparatus which may differ depending on the position of the tensioning apparatus and the joining apparatus within the strapping device and due to the different actions in the strapping process. Further, using the first clutch and the second clutch, the first actuating device and the tensioning apparatus, respectively, and the second actuating device and the joining apparatus, respectively, can selectively be coupled with a shared actuating drive. The strapping device therefore provides the advantage that separate actuation of the tensioning apparatus and the joining apparatus can be provided by dedicated first and second actuating devices, respectively, while maintaining one actuating drive by using the first and second clutches for selectively coupling the actuating drive to the tensioning apparatus and the joining apparatus, respectively, and / or to the first and second actuating device, respectively. Therefore, an optimized gear mechanism comprising the first and second clutches, and the first and second actuating devices can be provided for the strapping device.

[0009] Preferably, the actuating drive is an electric motor. The first drive motion may be a rotating motion of the actuating drive in a first direction, for example a clockwise direction, whereas the second drive motion may be a rotating motion of the actuating drive in a second direction, for example a counterclockwise direction.

[0010] The strapping device may be a portable strapping device or a strapping head of a strapping machine.

[0011] In some embodiments, the first clutch is configured to decouple the tensioning apparatus from the actuating drive when the joining apparatus is coupled with the actuating drive by the second clutch, and the second clutch is configured to decouple the joining apparatus from the actuating drive when the tensioning apparatus is coupled with the actuating drive by the first clutch.

[0012] The first clutch and the second clutch may therefore be used to alternatingly couple and decouple, respectively, the tensioning apparatus and the joining apparatus with the actuating drive. In some embodiments, the strapping device comprises a control unit configured to control the first clutch and the second clutch to alternatingly couple the tensioning apparatus and the joining apparatus with the actuating drive. Relating the first clutch and the second clutch with each other such that an alternating coupling of the tensioning apparatus and the joining apparatus with the actuating drive is achieved provides the advantage that the actuating motions of the tensioning apparatus and the joining apparatus can be better separated which may improve reliability of the strapping process.

[0013] In some embodiments, the first actuating device is configured to execute on the tensioning apparatus a raising motion where the tensioning apparatus is at least partially moved from an active position to an open position and an activating motion where the tensioning apparatus is at least partially moved from the open position to the active position.

[0014] In particular, the first actuating device may execute the raising motion on the tensioning apparatus when the actuating drive is coupled with the first actuating device and the tensioning apparatus, respectively, by the first clutch.

[0015] In particular, the tensioning apparatus may be configured that in the open position a tensioning wheel of the tensioning apparatus is spaced from the strap and in the active position the tensioning wheel of the tensioning apparatus is in contact with the strap.

[0016] Thus, a strap may be introduced into the strapping device while the tensioning apparatus is in the open position. In the active position of the tensioning apparatus, the strap may be tensioned by the tensioning wheel.

[0017] In particular, in the open position of the tensioning apparatus, the tensioning wheel may be spaced from a tensioning base of the tensioning apparatus by a distance such that a strap may freely be moved between the tensioning wheel and the tensioning base. Thus, the distance between the tensioning wheel and the tensioning base in the open position may be larger than the thickness of a typical strap used in packaging. In the active position of the tensioning apparatus, the tensioning wheel may be close to the tensioning base such that a strap may be clamped between the tensioning wheel and the tensioning base and tension be applied to the strap. Thus, the distance between the tensioning wheel and the tensioning base in the active position may be smaller than the thickness of a typical strap used in packaging.

[0018] In some embodiments, the strapping device comprises an operating drive configured to drive the tensioning apparatus for tensioning the strap in the active position of the tensioning apparatus.

[0019] In particular, the operating drive may be used to rotate a tensioning wheel in the active position of the tensioning apparatus in order to tension the strap. The operating drive may be an electric motor coupled to the tensioning apparatus.

[0020] In some embodiments, the second actuating device is configured to execute on the joining apparatus a raising motion where the joining apparatus is at least partially moved from an active position to an open position and an activating motion where the joining apparatus is at least partially moved from the open position to the active position.

[0021] In particular, the second actuating device may execute the raising motion on the joining apparatus when the actuating drive is coupled with the second actuating device and the joining apparatus, respectively, by the second clutch.

[0022] In some embodiments, the joining apparatus is configured that in the open position a joining jaw of the joining apparatus is spaced from the two overlapping portions of the strap and in the active position the joining jaw of the joining apparatus is in contact with the two overlapping portions of the strap.

[0023] Thus, a strap may be introduced into the strapping device while the joining apparatus is in the open position. In the active position of the joining apparatus, the overlapping portions of the strap may be joined by the joining apparatus.

[0024] In particular, in the open position of the joining apparatus, the joining jaw may be spaced from a joining base of the joining apparatus by a distance such that a strap may freely be moved between the joining jaw and the joining base. Thus, the distance between the joining jaw and the joining base in the open position may be larger than the twice the thickness of a typical strap used in packaging. In the active position of the joining apparatus, the joining jaw may be close to the joining base such that two overlapping portions of a strap may be clamped between the joining jaw and the joining base and be joined. Thus, the distance between the joining jaw and the joining base in the active position may be smaller than twice the thickness of a typical strap used in packaging.

[0025] The joining jaw may be a welding crimper.

[0026] The joining apparatus may be an ultrasonic friction welder.

[0027] For introducing a strap, the actuating drive may be coupled by the first clutch to the first actuating device and the tensioning apparatus, respectively, and drive the first actuating device to move the tensioning apparatus to the open position. Further, the actuating drive may be coupled by the second clutch to the second actuating device and the joining apparatus, respectively, and drive the second actuating device to move the joining apparatus to the open position.

[0028] In particular, the first actuating device may be configured to maintain the tensioning apparatus in a specific position, for example the open position, when the first clutch decouples the actuating drive from the tensioning apparatus. Similarly, the second actuating device may be configured to maintain the joining apparatus in a specific position, for example the open position, when the second clutch decouples the actuating drive from the joining apparatus.

[0029] In some embodiments, the strapping device comprises an operating drive configured to drive the joining apparatus for joining the two overlapping portions of the strap in the active position of the joining apparatus.

[0030] In particular, the operating drive may be used to impose a periodic motion onto the joining jaw in the active position of the joining apparatus in order to join the overlapping portions of the strap. The operating drive may be an electric motor coupled to the joining apparatus.

[0031] In some embodiments, the strapping device comprises a shared operating drive configured to operate as the operating drive for the tensioning apparatus and as the operating drive for the joining apparatus.

[0032] The shared operating drive may selectively be coupled the tensioning apparatus or the joining apparatus. The strapping device may comprise a control unit configured to control the shared operating drive for selective coupling to the tensioning apparatus or the joining apparatus, respectively.

[0033] In some embodiments, the first clutch comprises a first freewheel and the second clutch comprises a second freewheel.

[0034] The first and second freewheels can be used to effectively decouple and couple, respectively, the first and second actuating devices from the actuating drive.

[0035] In some embodiments, the first freewheel comprises a free rotating direction which is oppositely oriented to a free rotating direction of the second freewheel, and the first freewheel comprises an engaging rotating direction which is oppositely oriented to an engaging rotating direction of the second freewheel.

[0036] Thus, the second freewheel may comprise a free rotating direction which is oppositely oriented to the free rotating direction of the first freewheel, and the second freewheel may comprise an engaging rotating direction which is oppositely oriented to the engaging rotating direction of the first freewheel.

[0037] By rotating the first freewheel in its free rotating direction, the first actuating device can effectively be decoupled from the actuating drive, as the drive motion of the actuating drive may rotate the first freewheel without moving the first actuating device. Similarly, the second actuating device may effectively be decoupled from the actuating drive by rotating the second freewheel in its free rotating direction, as the drive motion of the actuating drive may rotate the second freewheel without moving the second actuating device. In each of its free rotating directions, the first and second freewheels may therefore interrupt the transmission of the drive motion of the actuating drive to the first and second actuating device, respectively.

[0038] Further, the first freewheel may be used to couple the first actuating device to the actuating drive by rotating in its engaging direction where the drive motion of the actuating drive can be transmitted to the first actuating device. Similarly, the second freewheel may be used to couple the second actuating device to the actuating drive by rotating in its engaging direction where the drive motion of the actuating drive can be transmitted to the second actuating device.

[0039] Using oppositely oriented free rotating directions and engaging rotating directions for the first and second freewheels provides the advantage that a respective rotating direction may be related to opposite rotating directions of the actuating drive, which may be an electric motor. For example, the engaging rotating direction of the first freewheel may correspond to a clockwise rotating direction of the actuating drive, whereas the engaging rotating direction of the second freewheel may correspond to a counterclockwise rotating direction of the actuating drive. Similarly, the free rotating direction of the first freewheel may then correspond to a counterclockwise rotating direction of the actuating drive, whereas the free rotating direction of the second freewheel may correspond to a clockwise rotating direction of the actuating drive. The roles of the clockwise and counterclockwise rotating directions may be reversed, as can be seen by the person skilled in the art.

[0040] Using first and second freewheels for the first and second clutches therefore provides the advantage that the rotating directions of the actuating drive can be utilized to couple and decouple the actuating drive with the first and second actuating device (and thus with the tensioning apparatus and the joining apparatus), respectively, in an efficient manner.

[0041] In some embodiments, the first actuating device comprises a first eccentric shaft operatively connected to the tensioning apparatus and rotatable with the first freewheel in its engaging rotating direction.

[0042] Using the first eccentric shaft, a rotating drive motion of the actuating drive can be translated into a linear actuating motion of the first actuating device when the first clutch couples the actuating drive with the first actuating device by rotation of the first freewheel in its engaging rotating direction.

[0043] In some embodiments, the first freewheel and the first eccentric shaft are configured that a raising motion and an activating motion of the tensioning apparatus are executed cyclically while rotating the first freewheel in its engaging rotating direction.

[0044] The first freewheel and the first eccentric shaft therefore provide the advantage that the tensioning apparatus can be raised, i.e. deactivated, and lowered, i.e. activated, in a simple fashion, as the actuating drive can continuously execute a drive motion in a direction corresponding to the engaging rotating direction of the first freewheel. Therefore, change or reversal of the drive motion of the actuating drive for the actuation of the tensioning apparatus which may introduce complexities in the gear mechanism and / or the control of the strapping device, can be avoided.

[0045] In some embodiments, the strapping device comprises a first position sensor, preferably a first Hall sensor, arranged at the first eccentric shaft and configured to detect the angular position of the first eccentric shaft.

[0046] By detecting the angular position of the first eccentric shaft using the first position sensor, the current position of the tensioning apparatus can be determined. In particular, it can be determined whether the tensioning apparatus is in the open position or in the active position. This may particularly be advantageous where the raising motion and the activating motion of the tensioning apparatus is executed cyclically, since the gear mechanism comprising the first freewheel and the first eccentric shaft may not exhibit a specifically defined intermediate position between execution of a raising motion and an activating motion. In particular, the angular position of the first eccentric shaft between executing a raising motion and an activating motion may differ from cycle to cycle.

[0047] The actuating drive and / or the gear mechanism comprising the first freewheel and the first eccentric shaft, respectively, may be halted as soon as the first position sensor detects that the first eccentric shaft is at the required position, for example an open position or an active position.

[0048] In particular, the strapping device may comprise a control unit connected to the first position sensor and configured to determine the open position and / or the active position of the tensioning apparatus using the angular position of the first eccentric shaft detected by the first position sensor.

[0049] The first position sensor may therefore transmit the detection signal to the control unit. The control unit may be configured to control the actuating drive and / or the gear mechanism, respectively, depending on the detection signal received.

[0050] In some embodiments, the second actuating device comprises a second eccentric shaft operatively connected to the joining apparatus and rotatable with the second freewheel in its engaging rotating direction.

[0051] Using the second eccentric shaft, a rotating drive motion of the actuating drive can be translated into a linear actuating motion of the second actuating device when the second clutch couples the actuating drive with the second actuating device by rotation of the second freewheel in its engaging rotating direction.

[0052] In some embodiments, the second freewheel and the second eccentric shaft are configured that a raising motion and an activating motion of the joining apparatus are executed cyclically while rotating the second freewheel in its engaging rotating direction.

[0053] Using the second freewheel and the second eccentric shaft, the joining apparatus can therefore be raised, i.e. deactivated, and lowered, i.e. activated, in a simple fashion, as the actuating drive can continuously execute a drive motion in a direction corresponding to the engaging rotating direction of the second freewheel. Change or reversal of the drive motion of the actuating drive for the actuation of the joining apparatus which may introduce complexities in the gear mechanism and / or the control of the strapping device, can therefore be avoided. In particular, change or reversal of the drive motion can instead be used for selectively driving the actuation of the tensioning apparatus and of the joining apparatus, respectively, by means of the first and second freewheels.

[0054] In some embodiments, the strapping device comprises a second position sensor, preferably a second Hall sensor, arranged at the second eccentric shaft and configured to detect the angular position of the second eccentric shaft.

[0055] By detecting the angular position of the second eccentric shaft using the second position sensor, the current position of the joining apparatus can be determined. In particular, it can be determined whether the joining apparatus is in the open position or in the active position. This may particularly be advantageous where the raising motion and the activating motion of the joining apparatus is executed cyclically, since the gear mechanism comprising the second freewheel and the second eccentric shaft may not exhibit a specifically defined intermediate position between execution of a raising motion and an activating motion. In particular, the angular position of the second eccentric shaft between executing a raising motion and an activating motion may differ from cycle to cycle.

[0056] The actuating drive and / or the gear mechanism comprising the second freewheel and the second eccentric shaft, respectively, may be halted as soon as the second position sensor detects that the second eccentric shaft is at the required position, for example an open position or an active position.

[0057] Using a first and second position sensor with the tensioning apparatus and the joining apparatus, respectively, provides the advantage that required positions of the first and second eccentric shafts can be detected, since the gear mechanism may not exhibit a specifically defined intermediate position between actuation of the tensioning apparatus and actuation of the joining apparatus. In particular, the angular position of the shafts of the gear mechanism, such as the first and second eccentric shaft or a drive shaft of the actuating drive, may differ between cycles of actuation of the tensioning apparatus and actuation of the joining apparatus.

[0058] In some embodiments, the strapping device comprises a control unit connected to the second position sensor and configured to determine the open position and / or the active position of the joining apparatus using the angular position of the second eccentric shaft detected by the second position sensor.

[0059] The second position sensor may therefore transmit the detection signal to the control unit. The control unit may be configured to control the actuating drive and / or the gear mechanism, respectively, depending on the detection signal received.

[0060] In some embodiments, the strapping device comprises a shared control unit configured to operate as the control unit connected to the first position sensor and as the control unit connected to the second position sensor.

[0061] Using a shared control unit, the complexity and dimensions of the strapping device can further be reduced.

[0062] In some embodiments, the actuating drive comprises an electric motor, preferably a brushless DC motor, with a drive shaft that is parallel with the axes of the first and second freewheels.

[0063] By arranging the drive shaft of the actuating drive in parallel with the axes of the first and second freewheels, the gear mechanism and transmission of drive motions can be simplified.

[0064] In some embodiments, the drive shaft may be coaxial with the axis of the first freewheel and / or with the axis of the second freewheel.

[0065] In some embodiments, the strapping device comprises a belt which runs around the first and second freewheels and the drive shaft of the electric motor.

[0066] The belt provides the advantage that the drive shaft and the first and second freewheels can be arranged in a more flexible fashion.

[0067] In some embodiments, the drive shaft and the first and / or second freewheels are coupled using gear wheels engaging with each other.

[0068] In some embodiments, the first and second freewheels and the drive shaft of the electric motor are arranged such that the axes of the first and second freewheels and the axis of the drive shaft of the electric motor form longitudinal edges of a prism with a triangular base.

[0069] With such an arrangement of the drive shaft of the electric motor and the axes of the first and second freewheels, the gear mechanism can be designed in a compact fashion.Brief description of the drawings

[0070] The present invention will be explained in more detail, by way of exemplary embodiments, with reference to the schematic drawings, in which: Fig.1ashows an illustration of an interior part of an embodiment of a strapping device in a side view, with the tensioning apparatus being in an active position and the joining apparatus being in an open position; Fig.1bshows an interior part of the strapping device of Fig.1a with the tensioning apparatus being in an open position; Fig.1cshows the interior part of the strapping device of Fig.1a with the joining apparatus being in an active position; Fig.2ashows an interior part of the strapping device of Fig.1a in a perspective view from the rear side with respect to Fig.1a; Fig.2bshows the interior part of Fig.2a with the first actuating device having executed a raising motion on the tensioning apparatus; Fig.3shows a close-up to an interior part of an embodiment of a strapping device in the region of the drive shaft and the first and second eccentric shafts. Detailed description of exemplary embodiments

[0071] Figure 1a shows an illustration of an interior part of an embodiment of a strapping device 100 in a side view. The strapping device 100 comprises a tensioning apparatus 1 which is shown in an active position and a joining apparatus 2 shown in an open position. The tensioning apparatus 1 comprises a tensioning wheel 11 which may be pivoted around a first pivot axis 111 by a rocker 13. In the shown active position, the tensioning wheel 11 is lowered towards a tensioning base 12 such that a strap (not shown in Figure 1a) may be clamped between the tensioning wheel 11 and the tensioning base 12, in order to tension the strap. In the shown open position of the joining apparatus 2, a joining jaw 21 is spaced from a joining base 22 such that a strap may be moved between the joining jaw 21 and the joining base 22. In particular, the joining jaw 21 is spaced from the joining base 22 such that a strap loop may be formed, and two overlapping portions of the strap be positioned between joining base 22 and the joining jaw 21. The strapping device 100 may be a portable strapping device or a strapping head of a strapping machine.

[0072] The strapping device 100 further comprises a shared actuating drive 4 with a drive shaft 41, a first clutch 3.1 configured to couple the first actuating device and the tensioning apparatus 1 with the actuating drive 4 and a second clutch 3.2 configured to couple the second actuating device and the joining apparatus 2 with the actuating drive 4. The first clutch 3.1 comprises a first freewheel 3.11 and the second clutch 3.2 comprises a second freewheel 3.21. The free rotating direction of the first freewheel 3.11 is oppositely oriented to the free rotating direction of the second freewheel 3.21. Accordingly, the engaging rotating direction of the first freewheel 3.11 is oppositely oriented to the engaging rotating direction of the second freewheel 3.21. For example, the engaging rotating direction of the first freewheel 3.11 corresponds to a clockwise rotating direction of the actuating drive 4, whereas the engaging rotating direction of the second freewheel 3.21 corresponds to a counterclockwise rotating direction of the actuating drive 4. Accordingly, the free rotating direction of the first freewheel 3.11 corresponds to a counterclockwise rotating direction of the actuating drive 4, whereas the free rotating direction of the second freewheel 3.21 corresponds to a clockwise rotating direction of the actuating drive 4.

[0073] The drive shaft 41 is arranged in parallel with the axis of the first freewheel 3.11 and the axis of the second freewheel 3.21. A toothed belt 42 runs around the first and second freewheels 3.11, 3.21 and the drive shaft 41 and therefore transmits the drive motion of the actuating drive 4 to the first and second freewheels 3.11, 3.21. The axes of the first and second freewheels 3.11, 3.21 and the axis of the drive shaft 41 form longitudinal edges of a prism with a triangular base or, in other words, the intersection points of the axes of the first and second freewheels 3.11, 3.21 and the axis of the drive shaft 41 with the plane of drawing of Figure 1 form the corners of a triangle, allowing a compact design of the gear mechanism of the strapping device 100.

[0074] Figure 1b shows the interior part of the strapping device 100 of Figure 1a with a part of the housing 10 as shown in Figure 1a being omitted for better visibility of further components of the strapping device 100. Compared to the configuration as shown in Figure 1a, the tensioning apparatus 1 is in an open position where the tensioning wheel 11 is raised away from the tensioning base 12, such that a strap can freely be moved between the tensioning wheel 11 and the tensioning base 12. The tensioning wheel 11 has been raised by a first actuating device 5.1 which is operatively connected to the tensioning apparatus 1 and to the freewheel 3.11 of the first clutch. By rotating the drive shaft 41 of the actuating drive 4 in the engaging direction of the first freewheel 3.11, the drive motion of the actuating drive 4 is transmitted to the first actuating device 5.1, such that the first actuating device 5.1 executes an actuating motion on the tensioning apparatus 1, pivoting the rocker 13 around the first pivoting axis 111, such that the tensioning wheel 11 is raised. Since the engaging direction of the first freewheel 3.11 corresponds to the free rotating direction of the second freewheel 3.21, the drive motion of the actuating drive 4 is not transmitted to the second actuating device 5.2 while the tensioning apparatus 1 is actuated by the first actuating device 5.1, and the joining apparatus 2 remains in the open position as shown in Figure 1a.

[0075] Figure 1c shows the interior part of the strapping device 100 of Figure 1a with the joining apparatus 2 being in the active position where the joining jaw 21 is lowered onto the joining base 22 such that two overlapping portions of a strap (not shown in Figure 1c) are clamped between the joining jaw 21 and the joining base 22 and can be joined. In the shown example, the joining apparatus 2 is a friction welder, and the overlapping portions of a strap may be joined by friction welding. The joining jaw 21 has been lowered towards the joining base 22 by the second actuating device 5.2 executing an actuating motion on the joining apparatus 2. Starting from the configuration as shown in Figure 1a, the drive shaft 41 has been rotated in the engaging direction of the second freewheel 3.21, such that the drive motion of the actuating drive 4 is transmitted to the second actuating device 5.2. Since the engaging direction of the second freewheel 3.21 corresponds to the free rotating direction of the first freewheel 3.11, the drive motion of the actuating drive 4 is not transmitted to the first actuating device while the joining apparatus 2 is actuated by the second actuating device 5.2, and the tensioning apparatus 1 remains in the active position as shown in Figure 1a. Thus, after tensioning the strap with the tensioning apparatus 1, the joining apparatus 2 can be moved to the active position where the overlapping portions of the strap can be joined. The tensioning operation and the joining operation are driven by a shared operating drive (not shown in Figure 1c). The shared operating drive is controlled by a control unit to selectively couple the shared operating drive to the tensioning apparatus or the joining apparatus, respectively.

[0076] Figure 2a an interior part of the strapping device 100 of Figure 1a in a perspective view from the rear side with respect to Figure 1a. The first eccentric shaft 5.11 of the first actuating device 5.1 is configured to actuate an actuation rod 5.12 to execute a linear motion when the first freewheel is rotated in its engaging direction due to the first drive motion of the actuating drive 4 which is transmitted via the belt 42 and the coupling of the first clutch. The actuation rod 5.12 actuates a lever 131 of the rocker 13 such that the tensioning wheel 11 can be lowered and raised, respectively. The first actuating device 5.1 further comprises a spring 5.12 limiting the force applied to the lever 131, such that different thicknesses of the straps used can be taken into account and tolerances can be balanced. In the shown configuration, the first eccentric shaft 5.11 of the first actuating device 5.1 has pushed the actuation rod 5.12 and the lever 131 downwards, thereby executing an activating motion on the tensioning apparatus 1 such that the tensioning wheel 11 is moved to the active position.

[0077] The tensioning apparatus 1 comprises a planetary gear set 14 of which the outer ring gear 141 can be seen in Figure 2a. In addition to the internal toothing meshing with the planet gears, the outer ring gear 141 comprises an outer toothing 142. A brake lever 5.14 arranged at a lower end region of the actuation rod 5.12 is configured to engage into the outer toothing 142 of the outer ring gear 141, depending on the linear position of the actuation rod 5.12. In the shown configuration where the tensioning apparatus 1 is in the active position, the brake lever 5.14 is engaged with the outer toothing 142 of the outer ring gear 141, thereby locking the outer ring gear 141.

[0078] Figure 2b shows the interior part of Figure 2a with the first actuating device 5.1 having executed a raising motion on the tensioning apparatus 1. Compared to the configuration shown in Figure 2a, the first eccentric shaft 5.11 has been rotated by the actuating drive 4 continuing the first drive motion such that the first actuating device 5.1 executes a raising motion on the tensioning apparatus 1 by raising the lever 131 of the rocker 13 such that the tensioning wheel is moved to the open position. The raising motion executed by the first actuating device 5.1 disengages the brake lever 5.14 from the outer toothing 142 of the outer ring gear 141 such that the outer ring gear 141 is unlocked. By continuing the first drive motion bay the drive 4, the configuration of Figure 2a is eventually reached again, since the first actuating device 5.1 starts to execute an activating motion on the tensioning apparatus 1 after completing the raising motion. Raising and activating motion on the tensioning apparatus 1 is therefore executed cyclically by the first actuating device 5.1. However, the angular position of the first eccentric shaft 5.11 may differ from cycle to cycle.

[0079] As the actuating drive 4 rotates the drive shaft in the engaging direction of the first freewheel for reaching the configuration of Figure 2b, the second actuating device 5.2 does not execute any actuating motion on the joining jaw 21, which is pivotably mounted on a second pivot axis 211, since the second freewheel is rotated in its free rotating direction. However, by rotating the drive shaft of the actuating drive 4 in the engaging direction of the second freewheel, opposite to the engaging direction of the first freewheel (or corresponding to the free rotating direction of the first freewheel, respectively), the second eccentric shaft 5.21 can be rotated such that the second actuating device can cyclically execute an activating and raising motion on the joining jaw 21. However, the angular position of the second eccentric shaft 5.21 may differ from cycle to cycle. In Figure 2b, the eccentric element of the eccentric shaft 5.21 is hidden behind a part of the housing 10.

[0080] Figure 3 shows a close-up to an interior part of an embodiment of a strapping device 100 in the region of the actuating drive 4 and the first and second eccentric shafts 5.11, 5.21. A first position sensor, realized by a first Hall sensor 5.15, is arranged at the first eccentric shaft 5.11. The first Hall sensor 5.15 is configured to detect the angular position of the first eccentric shaft 5.11 such that the current position of the tensioning apparatus and the tensioning wheel, respectively, can be determined. Similarly, a second position sensor, realized by a second Hall sensor 5.25, is arranged at the second eccentric shaft 5.21. The second Hall sensor 5.25 is configured to detect the angular position of the second eccentric shaft 5.21 such that the current position of the joining apparatus and the joining jaw, respectively, can be determined. The strapping device 100 comprises a control unit (not shown in Figure 3) connected to the first Hall sensor 5.15 and the second Hall sensor 5.25. The control unit is configured to determine the open position and / or the active position of the tensioning apparatus using the angular position of the first eccentric shaft 5.11 detected by the first Hall sensor 5.15. Similarly, the control unit is configured to determine the open position and / or the active position of the joining apparatus using the angular position of the second eccentric shaft 5.21 detected by the second Hall sensor 5.25.

[0081] The actuating drive 4 and the gear mechanism of the strapping device 100 comprising the first and second eccentric shafts 5.11, 5.21 may be halted as soon as the first or second Hall sensor 5.15, 5.25 detects that the first or second eccentric shaft 5.11, 5.21 is at a required position, for example an open position or an active position of the tensioning apparatus or joining apparatus.

Examples

Embodiment Construction

[0071]Figure 1a shows an illustration of an interior part of an embodiment of a strapping device 100 in a side view. The strapping device 100 comprises a tensioning apparatus 1 which is shown in an active position and a joining apparatus 2 shown in an open position. The tensioning apparatus 1 comprises a tensioning wheel 11 which may be pivoted around a first pivot axis 111 by a rocker 13. In the shown active position, the tensioning wheel 11 is lowered towards a tensioning base 12 such that a strap (not shown in Figure 1a) may be clamped between the tensioning wheel 11 and the tensioning base 12, in order to tension the strap. In the shown open position of the joining apparatus 2, a joining jaw 21 is spaced from a joining base 22 such that a strap may be moved between the joining jaw 21 and the joining base 22. In particular, the joining jaw 21 is spaced from the joining base 22 such that a strap loop may be formed, and two overlapping portions of the strap be positioned between jo...

Field of the invention

[0001] The present invention relates to a strapping device for strapping one or more articles with a strap.Background of the invention

[0002] Strapping devices are used for packing various articles by placing a strap around the articles such that two portions of the strap overlap each other by forming a loop around the articles. The overlapping portions of the strap are connected to each other by a strapping device which is applied to tension the strap and to join the overlapping portions of the strap. For tensioning the strap, a tensioning apparatus with a tensioning wheel is used which can be lowered onto the strap in order to contact the strap for tensioning and raised from the strap in order to release or to introduce the strap. Various joining techniques can be used for joining the overlapping portion, such as for example welding, crimping, gluing etc., the specific technique depending on the articles to be strapped and / or the material of the strap. For joining the overlapping portions of the strap, a welding crimper can be lowered onto the strap in order to join the overlapping portions of the strap and raised from the strap in order to release or to introduce the strap.

[0003] For example, DE 10 2011 122 157 A1 describes a strapping apparatus for strapping a tensioning strap around a packaged item, said apparatus including a frictional wheel which works against a support for tightening the named tensioning strap, wherein the frictional wheel is operatively connected to a drive and is liftable from the support by means of a pivot lever. The pivot lever arm is provided with an interrupting element in order to interrupt the path of action between the frictional wheel and the drive. A gear unit is provided in the path of action between the frictional wheel and the drive and the interrupting element acts on an element of said gear unit. The gear unit is arranged in or on a bearing block, the bearing block being tiltable by means of the pivot lever. As a result of the tilting of the bearing block, the gear unit can be tilted simultaneously in this case and the frictional wheel which is connected thereto can also be lifted off at the same time. An elastic means, for example a spring or a helical spring, is arranged between the pivot lever and the bearing block. The elastic means has the effect of pivoting the pivot lever back automatically in the case of its non-actuation.Summary of the invention

[0004] While packing articles, it is desired to provide a strapping device where the tensioning apparatus and the joining apparatus can be operated in a precise and an efficient manner.

[0005] It is therefore an object of the invention to provide a strapping device which at least partially improves the prior art and avoids at least part of the disadvantages of the prior art.

[0006] According to the present invention, this object is achieved by the features of the independent claims. In addition, further advantageous embodiments follow from the dependent claims and the description as well as the figures.

[0007] According to an aspect of the invention, this object is particularly achieved by a strapping device for strapping one or more articles with a strap, comprising a tensioning apparatus for tensioning the strap around the one or more articles, a joining apparatus for joining two overlapping portions of the strap, a first actuating device operatively connected to the tensioning apparatus, a second actuating device operatively connected to the joining apparatus, an actuating drive, a first clutch configured to couple the tensioning apparatus with the actuating drive and a second clutch configured to couple the joining apparatus with the actuating drive, wherein the first actuating device is configured to execute on the tensioning apparatus an actuating motion generated by a first drive motion of the actuating drive via the coupling of the first clutch, and the second actuating device is configured to execute on the joining apparatus an actuating motion generated by a second drive motion of the actuating drive via the coupling of the second clutch.

[0008] By providing a first actuating device for the tensioning apparatus and a second actuating device for the joining apparatus, the strapping device can be optimized for the respective actuating motions required for the tensioning apparatus and the joining apparatus which may differ depending on the position of the tensioning apparatus and the joining apparatus within the strapping device and due to the different actions in the strapping process. Further, using the first clutch and the second clutch, the first actuating device and the tensioning apparatus, respectively, and the second actuating device and the joining apparatus, respectively, can selectively be coupled with a shared actuating drive. The strapping device therefore provides the advantage that separate actuation of the tensioning apparatus and the joining apparatus can be provided by dedicated first and second actuating devices, respectively, while maintaining one actuating drive by using the first and second clutches for selectively coupling the actuating drive to the tensioning apparatus and the joining apparatus, respectively, and / or to the first and second actuating device, respectively. Therefore, an optimized gear mechanism comprising the first and second clutches, and the first and second actuating devices can be provided for the strapping device.

[0009] Preferably, the actuating drive is an electric motor. The first drive motion may be a rotating motion of the actuating drive in a first direction, for example a clockwise direction, whereas the second drive motion may be a rotating motion of the actuating drive in a second direction, for example a counterclockwise direction.

[0010] The strapping device may be a portable strapping device or a strapping head of a strapping machine.

[0011] In some embodiments, the first clutch is configured to decouple the tensioning apparatus from the actuating drive when the joining apparatus is coupled with the actuating drive by the second clutch, and the second clutch is configured to decouple the joining apparatus from the actuating drive when the tensioning apparatus is coupled with the actuating drive by the first clutch.

[0012] The first clutch and the second clutch may therefore be used to alternatingly couple and decouple, respectively, the tensioning apparatus and the joining apparatus with the actuating drive. In some embodiments, the strapping device comprises a control unit configured to control the first clutch and the second clutch to alternatingly couple the tensioning apparatus and the joining apparatus with the actuating drive. Relating the first clutch and the second clutch with each other such that an alternating coupling of the tensioning apparatus and the joining apparatus with the actuating drive is achieved provides the advantage that the actuating motions of the tensioning apparatus and the joining apparatus can be better separated which may improve reliability of the strapping process.

[0013] In some embodiments, the first actuating device is configured to execute on the tensioning apparatus a raising motion where the tensioning apparatus is at least partially moved from an active position to an open position and an activating motion where the tensioning apparatus is at least partially moved from the open position to the active position.

[0014] In particular, the first actuating device may execute the raising motion on the tensioning apparatus when the actuating drive is coupled with the first actuating device and the tensioning apparatus, respectively, by the first clutch.

[0015] In particular, the tensioning apparatus may be configured that in the open position a tensioning wheel of the tensioning apparatus is spaced from the strap and in the active position the tensioning wheel of the tensioning apparatus is in contact with the strap.

[0016] Thus, a strap may be introduced into the strapping device while the tensioning apparatus is in the open position. In the active position of the tensioning apparatus, the strap may be tensioned by the tensioning wheel.

[0017] In particular, in the open position of the tensioning apparatus, the tensioning wheel may be spaced from a tensioning base of the tensioning apparatus by a distance such that a strap may freely be moved between the tensioning wheel and the tensioning base. Thus, the distance between the tensioning wheel and the tensioning base in the open position may be larger than the thickness of a typical strap used in packaging. In the active position of the tensioning apparatus, the tensioning wheel may be close to the tensioning base such that a strap may be clamped between the tensioning wheel and the tensioning base and tension be applied to the strap. Thus, the distance between the tensioning wheel and the tensioning base in the active position may be smaller than the thickness of a typical strap used in packaging.

[0018] In some embodiments, the strapping device comprises an operating drive configured to drive the tensioning apparatus for tensioning the strap in the active position of the tensioning apparatus.

[0019] In particular, the operating drive may be used to rotate a tensioning wheel in the active position of the tensioning apparatus in order to tension the strap. The operating drive may be an electric motor coupled to the tensioning apparatus.

[0020] In some embodiments, the second actuating device is configured to execute on the joining apparatus a raising motion where the joining apparatus is at least partially moved from an active position to an open position and an activating motion where the joining apparatus is at least partially moved from the open position to the active position.

[0021] In particular, the second actuating device may execute the raising motion on the joining apparatus when the actuating drive is coupled with the second actuating device and the joining apparatus, respectively, by the second clutch.

[0022] In some embodiments, the joining apparatus is configured that in the open position a joining jaw of the joining apparatus is spaced from the two overlapping portions of the strap and in the active position the joining jaw of the joining apparatus is in contact with the two overlapping portions of the strap.

[0023] Thus, a strap may be introduced into the strapping device while the joining apparatus is in the open position. In the active position of the joining apparatus, the overlapping portions of the strap may be joined by the joining apparatus.

[0024] In particular, in the open position of the joining apparatus, the joining jaw may be spaced from a joining base of the joining apparatus by a distance such that a strap may freely be moved between the joining jaw and the joining base. Thus, the distance between the joining jaw and the joining base in the open position may be larger than the twice the thickness of a typical strap used in packaging. In the active position of the joining apparatus, the joining jaw may be close to the joining base such that two overlapping portions of a strap may be clamped between the joining jaw and the joining base and be joined. Thus, the distance between the joining jaw and the joining base in the active position may be smaller than twice the thickness of a typical strap used in packaging.

[0025] The joining jaw may be a welding crimper.

[0026] The joining apparatus may be an ultrasonic friction welder.

[0027] For introducing a strap, the actuating drive may be coupled by the first clutch to the first actuating device and the tensioning apparatus, respectively, and drive the first actuating device to move the tensioning apparatus to the open position. Further, the actuating drive may be coupled by the second clutch to the second actuating device and the joining apparatus, respectively, and drive the second actuating device to move the joining apparatus to the open position.

[0028] In particular, the first actuating device may be configured to maintain the tensioning apparatus in a specific position, for example the open position, when the first clutch decouples the actuating drive from the tensioning apparatus. Similarly, the second actuating device may be configured to maintain the joining apparatus in a specific position, for example the open position, when the second clutch decouples the actuating drive from the joining apparatus.

[0029] In some embodiments, the strapping device comprises an operating drive configured to drive the joining apparatus for joining the two overlapping portions of the strap in the active position of the joining apparatus.

[0030] In particular, the operating drive may be used to impose a periodic motion onto the joining jaw in the active position of the joining apparatus in order to join the overlapping portions of the strap. The operating drive may be an electric motor coupled to the joining apparatus.

[0031] In some embodiments, the strapping device comprises a shared operating drive configured to operate as the operating drive for the tensioning apparatus and as the operating drive for the joining apparatus.

[0032] The shared operating drive may selectively be coupled the tensioning apparatus or the joining apparatus. The strapping device may comprise a control unit configured to control the shared operating drive for selective coupling to the tensioning apparatus or the joining apparatus, respectively.

[0033] In some embodiments, the first clutch comprises a first freewheel and the second clutch comprises a second freewheel.

[0034] The first and second freewheels can be used to effectively decouple and couple, respectively, the first and second actuating devices from the actuating drive.

[0035] In some embodiments, the first freewheel comprises a free rotating direction which is oppositely oriented to a free rotating direction of the second freewheel, and the first freewheel comprises an engaging rotating direction which is oppositely oriented to an engaging rotating direction of the second freewheel.

[0036] Thus, the second freewheel may comprise a free rotating direction which is oppositely oriented to the free rotating direction of the first freewheel, and the second freewheel may comprise an engaging rotating direction which is oppositely oriented to the engaging rotating direction of the first freewheel.

[0037] By rotating the first freewheel in its free rotating direction, the first actuating device can effectively be decoupled from the actuating drive, as the drive motion of the actuating drive may rotate the first freewheel without moving the first actuating device. Similarly, the second actuating device may effectively be decoupled from the actuating drive by rotating the second freewheel in its free rotating direction, as the drive motion of the actuating drive may rotate the second freewheel without moving the second actuating device. In each of its free rotating directions, the first and second freewheels may therefore interrupt the transmission of the drive motion of the actuating drive to the first and second actuating device, respectively.

[0038] Further, the first freewheel may be used to couple the first actuating device to the actuating drive by rotating in its engaging direction where the drive motion of the actuating drive can be transmitted to the first actuating device. Similarly, the second freewheel may be used to couple the second actuating device to the actuating drive by rotating in its engaging direction where the drive motion of the actuating drive can be transmitted to the second actuating device.

[0039] Using oppositely oriented free rotating directions and engaging rotating directions for the first and second freewheels provides the advantage that a respective rotating direction may be related to opposite rotating directions of the actuating drive, which may be an electric motor. For example, the engaging rotating direction of the first freewheel may correspond to a clockwise rotating direction of the actuating drive, whereas the engaging rotating direction of the second freewheel may correspond to a counterclockwise rotating direction of the actuating drive. Similarly, the free rotating direction of the first freewheel may then correspond to a counterclockwise rotating direction of the actuating drive, whereas the free rotating direction of the second freewheel may correspond to a clockwise rotating direction of the actuating drive. The roles of the clockwise and counterclockwise rotating directions may be reversed, as can be seen by the person skilled in the art.

[0040] Using first and second freewheels for the first and second clutches therefore provides the advantage that the rotating directions of the actuating drive can be utilized to couple and decouple the actuating drive with the first and second actuating device (and thus with the tensioning apparatus and the joining apparatus), respectively, in an efficient manner.

[0041] In some embodiments, the first actuating device comprises a first eccentric shaft operatively connected to the tensioning apparatus and rotatable with the first freewheel in its engaging rotating direction.

[0042] Using the first eccentric shaft, a rotating drive motion of the actuating drive can be translated into a linear actuating motion of the first actuating device when the first clutch couples the actuating drive with the first actuating device by rotation of the first freewheel in its engaging rotating direction.

[0043] In some embodiments, the first freewheel and the first eccentric shaft are configured that a raising motion and an activating motion of the tensioning apparatus are executed cyclically while rotating the first freewheel in its engaging rotating direction.

[0044] The first freewheel and the first eccentric shaft therefore provide the advantage that the tensioning apparatus can be raised, i.e. deactivated, and lowered, i.e. activated, in a simple fashion, as the actuating drive can continuously execute a drive motion in a direction corresponding to the engaging rotating direction of the first freewheel. Therefore, change or reversal of the drive motion of the actuating drive for the actuation of the tensioning apparatus which may introduce complexities in the gear mechanism and / or the control of the strapping device, can be avoided.

[0045] In some embodiments, the strapping device comprises a first position sensor, preferably a first Hall sensor, arranged at the first eccentric shaft and configured to detect the angular position of the first eccentric shaft.

[0046] By detecting the angular position of the first eccentric shaft using the first position sensor, the current position of the tensioning apparatus can be determined. In particular, it can be determined whether the tensioning apparatus is in the open position or in the active position. This may particularly be advantageous where the raising motion and the activating motion of the tensioning apparatus is executed cyclically, since the gear mechanism comprising the first freewheel and the first eccentric shaft may not exhibit a specifically defined intermediate position between execution of a raising motion and an activating motion. In particular, the angular position of the first eccentric shaft between executing a raising motion and an activating motion may differ from cycle to cycle.

[0047] The actuating drive and / or the gear mechanism comprising the first freewheel and the first eccentric shaft, respectively, may be halted as soon as the first position sensor detects that the first eccentric shaft is at the required position, for example an open position or an active position.

[0048] In particular, the strapping device may comprise a control unit connected to the first position sensor and configured to determine the open position and / or the active position of the tensioning apparatus using the angular position of the first eccentric shaft detected by the first position sensor.

[0049] The first position sensor may therefore transmit the detection signal to the control unit. The control unit may be configured to control the actuating drive and / or the gear mechanism, respectively, depending on the detection signal received.

[0050] In some embodiments, the second actuating device comprises a second eccentric shaft operatively connected to the joining apparatus and rotatable with the second freewheel in its engaging rotating direction.

[0051] Using the second eccentric shaft, a rotating drive motion of the actuating drive can be translated into a linear actuating motion of the second actuating device when the second clutch couples the actuating drive with the second actuating device by rotation of the second freewheel in its engaging rotating direction.

[0052] In some embodiments, the second freewheel and the second eccentric shaft are configured that a raising motion and an activating motion of the joining apparatus are executed cyclically while rotating the second freewheel in its engaging rotating direction.

[0053] Using the second freewheel and the second eccentric shaft, the joining apparatus can therefore be raised, i.e. deactivated, and lowered, i.e. activated, in a simple fashion, as the actuating drive can continuously execute a drive motion in a direction corresponding to the engaging rotating direction of the second freewheel. Change or reversal of the drive motion of the actuating drive for the actuation of the joining apparatus which may introduce complexities in the gear mechanism and / or the control of the strapping device, can therefore be avoided. In particular, change or reversal of the drive motion can instead be used for selectively driving the actuation of the tensioning apparatus and of the joining apparatus, respectively, by means of the first and second freewheels.

[0054] In some embodiments, the strapping device comprises a second position sensor, preferably a second Hall sensor, arranged at the second eccentric shaft and configured to detect the angular position of the second eccentric shaft.

[0055] By detecting the angular position of the second eccentric shaft using the second position sensor, the current position of the joining apparatus can be determined. In particular, it can be determined whether the joining apparatus is in the open position or in the active position. This may particularly be advantageous where the raising motion and the activating motion of the joining apparatus is executed cyclically, since the gear mechanism comprising the second freewheel and the second eccentric shaft may not exhibit a specifically defined intermediate position between execution of a raising motion and an activating motion. In particular, the angular position of the second eccentric shaft between executing a raising motion and an activating motion may differ from cycle to cycle.

[0056] The actuating drive and / or the gear mechanism comprising the second freewheel and the second eccentric shaft, respectively, may be halted as soon as the second position sensor detects that the second eccentric shaft is at the required position, for example an open position or an active position.

[0057] Using a first and second position sensor with the tensioning apparatus and the joining apparatus, respectively, provides the advantage that required positions of the first and second eccentric shafts can be detected, since the gear mechanism may not exhibit a specifically defined intermediate position between actuation of the tensioning apparatus and actuation of the joining apparatus. In particular, the angular position of the shafts of the gear mechanism, such as the first and second eccentric shaft or a drive shaft of the actuating drive, may differ between cycles of actuation of the tensioning apparatus and actuation of the joining apparatus.

[0058] In some embodiments, the strapping device comprises a control unit connected to the second position sensor and configured to determine the open position and / or the active position of the joining apparatus using the angular position of the second eccentric shaft detected by the second position sensor.

[0059] The second position sensor may therefore transmit the detection signal to the control unit. The control unit may be configured to control the actuating drive and / or the gear mechanism, respectively, depending on the detection signal received.

[0060] In some embodiments, the strapping device comprises a shared control unit configured to operate as the control unit connected to the first position sensor and as the control unit connected to the second position sensor.

[0061] Using a shared control unit, the complexity and dimensions of the strapping device can further be reduced.

[0062] In some embodiments, the actuating drive comprises an electric motor, preferably a brushless DC motor, with a drive shaft that is parallel with the axes of the first and second freewheels.

[0063] By arranging the drive shaft of the actuating drive in parallel with the axes of the first and second freewheels, the gear mechanism and transmission of drive motions can be simplified.

[0064] In some embodiments, the drive shaft may be coaxial with the axis of the first freewheel and / or with the axis of the second freewheel.

[0065] In some embodiments, the strapping device comprises a belt which runs around the first and second freewheels and the drive shaft of the electric motor.

[0066] The belt provides the advantage that the drive shaft and the first and second freewheels can be arranged in a more flexible fashion.

[0067] In some embodiments, the drive shaft and the first and / or second freewheels are coupled using gear wheels engaging with each other.

[0068] In some embodiments, the first and second freewheels and the drive shaft of the electric motor are arranged such that the axes of the first and second freewheels and the axis of the drive shaft of the electric motor form longitudinal edges of a prism with a triangular base.

[0069] With such an arrangement of the drive shaft of the electric motor and the axes of the first and second freewheels, the gear mechanism can be designed in a compact fashion.Brief description of the drawings

[0070] The present invention will be explained in more detail, by way of exemplary embodiments, with reference to the schematic drawings, in which: Fig.1ashows an illustration of an interior part of an embodiment of a strapping device in a side view, with the tensioning apparatus being in an active position and the joining apparatus being in an open position; Fig.1bshows an interior part of the strapping device of Fig.1a with the tensioning apparatus being in an open position; Fig.1cshows the interior part of the strapping device of Fig.1a with the joining apparatus being in an active position; Fig.2ashows an interior part of the strapping device of Fig.1a in a perspective view from the rear side with respect to Fig.1a; Fig.2bshows the interior part of Fig.2a with the first actuating device having executed a raising motion on the tensioning apparatus; Fig.3shows a close-up to an interior part of an embodiment of a strapping device in the region of the drive shaft and the first and second eccentric shafts. Detailed description of exemplary embodiments

[0071] Figure 1a shows an illustration of an interior part of an embodiment of a strapping device 100 in a side view. The strapping device 100 comprises a tensioning apparatus 1 which is shown in an active position and a joining apparatus 2 shown in an open position. The tensioning apparatus 1 comprises a tensioning wheel 11 which may be pivoted around a first pivot axis 111 by a rocker 13. In the shown active position, the tensioning wheel 11 is lowered towards a tensioning base 12 such that a strap (not shown in Figure 1a) may be clamped between the tensioning wheel 11 and the tensioning base 12, in order to tension the strap. In the shown open position of the joining apparatus 2, a joining jaw 21 is spaced from a joining base 22 such that a strap may be moved between the joining jaw 21 and the joining base 22. In particular, the joining jaw 21 is spaced from the joining base 22 such that a strap loop may be formed, and two overlapping portions of the strap be positioned between joining base 22 and the joining jaw 21. The strapping device 100 may be a portable strapping device or a strapping head of a strapping machine.

[0072] The strapping device 100 further comprises a shared actuating drive 4 with a drive shaft 41, a first clutch 3.1 configured to couple the first actuating device and the tensioning apparatus 1 with the actuating drive 4 and a second clutch 3.2 configured to couple the second actuating device and the joining apparatus 2 with the actuating drive 4. The first clutch 3.1 comprises a first freewheel 3.11 and the second clutch 3.2 comprises a second freewheel 3.21. The free rotating direction of the first freewheel 3.11 is oppositely oriented to the free rotating direction of the second freewheel 3.21. Accordingly, the engaging rotating direction of the first freewheel 3.11 is oppositely oriented to the engaging rotating direction of the second freewheel 3.21. For example, the engaging rotating direction of the first freewheel 3.11 corresponds to a clockwise rotating direction of the actuating drive 4, whereas the engaging rotating direction of the second freewheel 3.21 corresponds to a counterclockwise rotating direction of the actuating drive 4. Accordingly, the free rotating direction of the first freewheel 3.11 corresponds to a counterclockwise rotating direction of the actuating drive 4, whereas the free rotating direction of the second freewheel 3.21 corresponds to a clockwise rotating direction of the actuating drive 4.

[0073] The drive shaft 41 is arranged in parallel with the axis of the first freewheel 3.11 and the axis of the second freewheel 3.21. A toothed belt 42 runs around the first and second freewheels 3.11, 3.21 and the drive shaft 41 and therefore transmits the drive motion of the actuating drive 4 to the first and second freewheels 3.11, 3.21. The axes of the first and second freewheels 3.11, 3.21 and the axis of the drive shaft 41 form longitudinal edges of a prism with a triangular base or, in other words, the intersection points of the axes of the first and second freewheels 3.11, 3.21 and the axis of the drive shaft 41 with the plane of drawing of Figure 1 form the corners of a triangle, allowing a compact design of the gear mechanism of the strapping device 100.

[0074] Figure 1b shows the interior part of the strapping device 100 of Figure 1a with a part of the housing 10 as shown in Figure 1a being omitted for better visibility of further components of the strapping device 100. Compared to the configuration as shown in Figure 1a, the tensioning apparatus 1 is in an open position where the tensioning wheel 11 is raised away from the tensioning base 12, such that a strap can freely be moved between the tensioning wheel 11 and the tensioning base 12. The tensioning wheel 11 has been raised by a first actuating device 5.1 which is operatively connected to the tensioning apparatus 1 and to the freewheel 3.11 of the first clutch. By rotating the drive shaft 41 of the actuating drive 4 in the engaging direction of the first freewheel 3.11, the drive motion of the actuating drive 4 is transmitted to the first actuating device 5.1, such that the first actuating device 5.1 executes an actuating motion on the tensioning apparatus 1, pivoting the rocker 13 around the first pivoting axis 111, such that the tensioning wheel 11 is raised. Since the engaging direction of the first freewheel 3.11 corresponds to the free rotating direction of the second freewheel 3.21, the drive motion of the actuating drive 4 is not transmitted to the second actuating device 5.2 while the tensioning apparatus 1 is actuated by the first actuating device 5.1, and the joining apparatus 2 remains in the open position as shown in Figure 1a.

[0075] Figure 1c shows the interior part of the strapping device 100 of Figure 1a with the joining apparatus 2 being in the active position where the joining jaw 21 is lowered onto the joining base 22 such that two overlapping portions of a strap (not shown in Figure 1c) are clamped between the joining jaw 21 and the joining base 22 and can be joined. In the shown example, the joining apparatus 2 is a friction welder, and the overlapping portions of a strap may be joined by friction welding. The joining jaw 21 has been lowered towards the joining base 22 by the second actuating device 5.2 executing an actuating motion on the joining apparatus 2. Starting from the configuration as shown in Figure 1a, the drive shaft 41 has been rotated in the engaging direction of the second freewheel 3.21, such that the drive motion of the actuating drive 4 is transmitted to the second actuating device 5.2. Since the engaging direction of the second freewheel 3.21 corresponds to the free rotating direction of the first freewheel 3.11, the drive motion of the actuating drive 4 is not transmitted to the first actuating device while the joining apparatus 2 is actuated by the second actuating device 5.2, and the tensioning apparatus 1 remains in the active position as shown in Figure 1a. Thus, after tensioning the strap with the tensioning apparatus 1, the joining apparatus 2 can be moved to the active position where the overlapping portions of the strap can be joined. The tensioning operation and the joining operation are driven by a shared operating drive (not shown in Figure 1c). The shared operating drive is controlled by a control unit to selectively couple the shared operating drive to the tensioning apparatus or the joining apparatus, respectively.

[0076] Figure 2a an interior part of the strapping device 100 of Figure 1a in a perspective view from the rear side with respect to Figure 1a. The first eccentric shaft 5.11 of the first actuating device 5.1 is configured to actuate an actuation rod 5.12 to execute a linear motion when the first freewheel is rotated in its engaging direction due to the first drive motion of the actuating drive 4 which is transmitted via the belt 42 and the coupling of the first clutch. The actuation rod 5.12 actuates a lever 131 of the rocker 13 such that the tensioning wheel 11 can be lowered and raised, respectively. The first actuating device 5.1 further comprises a spring 5.12 limiting the force applied to the lever 131, such that different thicknesses of the straps used can be taken into account and tolerances can be balanced. In the shown configuration, the first eccentric shaft 5.11 of the first actuating device 5.1 has pushed the actuation rod 5.12 and the lever 131 downwards, thereby executing an activating motion on the tensioning apparatus 1 such that the tensioning wheel 11 is moved to the active position.

[0077] The tensioning apparatus 1 comprises a planetary gear set 14 of which the outer ring gear 141 can be seen in Figure 2a. In addition to the internal toothing meshing with the planet gears, the outer ring gear 141 comprises an outer toothing 142. A brake lever 5.14 arranged at a lower end region of the actuation rod 5.12 is configured to engage into the outer toothing 142 of the outer ring gear 141, depending on the linear position of the actuation rod 5.12. In the shown configuration where the tensioning apparatus 1 is in the active position, the brake lever 5.14 is engaged with the outer toothing 142 of the outer ring gear 141, thereby locking the outer ring gear 141.

[0078] Figure 2b shows the interior part of Figure 2a with the first actuating device 5.1 having executed a raising motion on the tensioning apparatus 1. Compared to the configuration shown in Figure 2a, the first eccentric shaft 5.11 has been rotated by the actuating drive 4 continuing the first drive motion such that the first actuating device 5.1 executes a raising motion on the tensioning apparatus 1 by raising the lever 131 of the rocker 13 such that the tensioning wheel is moved to the open position. The raising motion executed by the first actuating device 5.1 disengages the brake lever 5.14 from the outer toothing 142 of the outer ring gear 141 such that the outer ring gear 141 is unlocked. By continuing the first drive motion bay the drive 4, the configuration of Figure 2a is eventually reached again, since the first actuating device 5.1 starts to execute an activating motion on the tensioning apparatus 1 after completing the raising motion. Raising and activating motion on the tensioning apparatus 1 is therefore executed cyclically by the first actuating device 5.1. However, the angular position of the first eccentric shaft 5.11 may differ from cycle to cycle.

[0079] As the actuating drive 4 rotates the drive shaft in the engaging direction of the first freewheel for reaching the configuration of Figure 2b, the second actuating device 5.2 does not execute any actuating motion on the joining jaw 21, which is pivotably mounted on a second pivot axis 211, since the second freewheel is rotated in its free rotating direction. However, by rotating the drive shaft of the actuating drive 4 in the engaging direction of the second freewheel, opposite to the engaging direction of the first freewheel (or corresponding to the free rotating direction of the first freewheel, respectively), the second eccentric shaft 5.21 can be rotated such that the second actuating device can cyclically execute an activating and raising motion on the joining jaw 21. However, the angular position of the second eccentric shaft 5.21 may differ from cycle to cycle. In Figure 2b, the eccentric element of the eccentric shaft 5.21 is hidden behind a part of the housing 10.

[0080] Figure 3 shows a close-up to an interior part of an embodiment of a strapping device 100 in the region of the actuating drive 4 and the first and second eccentric shafts 5.11, 5.21. A first position sensor, realized by a first Hall sensor 5.15, is arranged at the first eccentric shaft 5.11. The first Hall sensor 5.15 is configured to detect the angular position of the first eccentric shaft 5.11 such that the current position of the tensioning apparatus and the tensioning wheel, respectively, can be determined. Similarly, a second position sensor, realized by a second Hall sensor 5.25, is arranged at the second eccentric shaft 5.21. The second Hall sensor 5.25 is configured to detect the angular position of the second eccentric shaft 5.21 such that the current position of the joining apparatus and the joining jaw, respectively, can be determined. The strapping device 100 comprises a control unit (not shown in Figure 3) connected to the first Hall sensor 5.15 and the second Hall sensor 5.25. The control unit is configured to determine the open position and / or the active position of the tensioning apparatus using the angular position of the first eccentric shaft 5.11 detected by the first Hall sensor 5.15. Similarly, the control unit is configured to determine the open position and / or the active position of the joining apparatus using the angular position of the second eccentric shaft 5.21 detected by the second Hall sensor 5.25.

[0081] The actuating drive 4 and the gear mechanism of the strapping device 100 comprising the first and second eccentric shafts 5.11, 5.21 may be halted as soon as the first or second Hall sensor 5.15, 5.25 detects that the first or second eccentric shaft 5.11, 5.21 is at a required position, for example an open position or an active position of the tensioning apparatus or joining apparatus.

Examples

Embodiment Construction

[0071]Figure 1a shows an illustration of an interior part of an embodiment of a strapping device 100 in a side view. The strapping device 100 comprises a tensioning apparatus 1 which is shown in an active position and a joining apparatus 2 shown in an open position. The tensioning apparatus 1 comprises a tensioning wheel 11 which may be pivoted around a first pivot axis 111 by a rocker 13. In the shown active position, the tensioning wheel 11 is lowered towards a tensioning base 12 such that a strap (not shown in Figure 1a) may be clamped between the tensioning wheel 11 and the tensioning base 12, in order to tension the strap. In the shown open position of the joining apparatus 2, a joining jaw 21 is spaced from a joining base 22 such that a strap may be moved between the joining jaw 21 and the joining base 22. In particular, the joining jaw 21 is spaced from the joining base 22 such that a strap loop may be formed, and two overlapping portions of the strap be positioned between jo...

Claims

1. A strapping device (100) for strapping one or more articles with a strap, comprising a tensioning apparatus (1) for tensioning the strap around the one or more articles, a joining apparatus (2) for joining two overlapping portions of the strap, a first actuating device (5.1) operatively connected to the tensioning apparatus (1), a second actuating device (5.2) operatively connected to the joining apparatus (2), an actuating drive (4), a first clutch (3.1) configured to couple the tensioning apparatus (1) with the actuating drive (4) and a second clutch (3.2) configured to couple the joining apparatus (2) with the actuating drive (4), wherein the first actuating device (5.1) is configured to execute on the tensioning apparatus (1) an actuating motion generated by a first drive motion of the actuating drive (4) via the coupling of the first clutch (3.1), and the second actuating device (3.2) is configured to execute on the joining apparatus (2) an actuating motion generated by a second drive motion of the actuating drive (4) via the coupling of the second clutch (3.2).

2. The strapping device (100) according to claim 1, wherein the first clutch (3.1) is configured to decouple the tensioning apparatus (1) from the actuating drive (4) when the joining apparatus (2) is coupled with the actuating drive (4) by the second clutch (3.2), and the second clutch (3.2) is configured to decouple the joining apparatus (2) from the actuating drive (4) when the tensioning apparatus (1) is coupled with the actuating drive (4) by the first clutch (3.1).

3. The strapping device (100) according to claim 1 or 2, wherein the first actuating device (5.1) is configured to execute on the tensioning apparatus (1) a raising motion where the tensioning apparatus (1) is at least partially moved from an active position to an open position and an activating motion where the tensioning apparatus (1) is at least partially moved from the open position to the active position, wherein the tensioning apparatus (1) is preferably configured that in the open position a tensioning wheel (11) of the tensioning apparatus (1) is spaced from the strap and in the active position the tensioning wheel (11) of the tensioning apparatus (1) is in contact with the strap, wherein the strapping device (100) preferably comprises an operating drive configured to drive the tensioning apparatus (1) for tensioning the strap in the active position of the tensioning apparatus (1) .

4. The strapping device (100) according to one of the preceding claims, wherein the second actuating device (5.2) is configured to execute on the joining apparatus (2) a raising motion where the joining apparatus (2) is at least partially moved from an active position to an open position and an activating motion where the joining apparatus (2) is at least partially moved from the open position to the active position, wherein the joining apparatus (2) is preferably configured that in the open position a joining jaw (21) of the joining apparatus (2) is spaced from the two overlapping portions of the strap and in the active position the joining jaw (21) of the joining apparatus (2) is in contact with the two overlapping portions of the strap, wherein the strapping device (100) preferably comprises an operating drive configured to drive the joining apparatus (2) for joining the two overlapping portions of the strap in the active position of the joining apparatus (2).

5. The strapping device (100) according to claim 3 and 4, wherein the strapping device (100) comprises a shared operating drive configured to operate as the operating drive for the tensioning apparatus (1) and as the operating drive for the joining apparatus (2).

6. The strapping device (100) according to one of the preceding claims, wherein the first clutch (3.1) comprises a first freewheel (3.11) and the second clutch (3.2) comprises a second freewheel (3.21), wherein the first freewheel (3.11) preferably comprises a free rotating direction which is oppositely oriented to a free rotating direction of the second freewheel (3.21), and the first freewheel (3.11) preferably comprises an engaging rotating direction which is oppositely oriented to an engaging rotating direction of the second freewheel (3.21), wherein the actuating drive (4) preferably comprises an electric motor, preferably a brushless DC motor, with a drive shaft (41) that is parallel with the axes of the first and second freewheels (3.11; 3.21).

7. The strapping device (100) according to claim 6, wherein the first actuating device (5.1) comprises a first eccentric shaft (5.11) operatively connected to the tensioning apparatus (1) and rotatable with the first freewheel (3.11) in its engaging rotating direction, wherein the first freewheel (3.11) and the first eccentric shaft (5.11) are preferably configured that a raising motion and an activating motion of the tensioning apparatus (1) are executed cyclically while rotating the first freewheel (3.11) in its engaging rotating direction.

8. The strapping device (100) according to claim 7, wherein the strapping device (100) comprises a first position sensor (5.15), preferably a first Hall sensor, arranged at the first eccentric shaft (5.11) and configured to detect the angular position of the first eccentric shaft (5.11).

9. The strapping device (100) according to claim 8, wherein the strapping device (100) comprises a control unit connected to the first position sensor (5.15) and configured to determine the open position and / or the active position of the tensioning apparatus (1) using the angular position of the first eccentric shaft (5.11) detected by the first position sensor (5.15).

10. The strapping device (100) according to one of the claims 6 to 9, wherein the second actuating device (5.2) comprises a second eccentric shaft (5.21) operatively connected to the joining apparatus (2) and rotatable with the second freewheel (3.21) in its engaging rotating direction, wherein the second freewheel (3.21) and the second eccentric shaft (5.21) are preferably configured that a raising motion and an activating motion of the joining apparatus (2) are executed cyclically while rotating the second freewheel (3.21) in its engaging rotating direction.

11. The strapping device (100) according to claim 10, wherein the strapping device (100) comprises a second position sensor (5.25), preferably a second Hall sensor, arranged at the second eccentric shaft (5.21) and configured to detect the angular position of the second eccentric shaft (5.21).

12. The strapping device (100) according to claim 11, wherein the strapping device (100) comprises a control unit connected to the second position sensor (5.25) and configured to determine the open position and / or the active position of the joining apparatus (2) using the angular position of the second eccentric shaft (5.21) detected by the second position sensor (5.25).

13. The strapping device (100) according to claim 9 and 12, wherein the strapping device (100) comprises a shared control unit configured to operate as the control unit connected to the first position sensor (5.15) and as the control unit connected to the second position sensor (5.25).

14. The strapping device (100) according to one of the claims 6 to 13, wherein the strapping device (100) comprises a belt (42) which runs around the first and second freewheels (3.11; 3.21) and the drive shaft (41) of the electric motor (4).

15. The strapping device (100) according to one of the claims 6 to 14, wherein the first and second freewheels (3.11; 3.21) and the drive shaft (41) of the electric motor (4) are arranged such that the axes of the first and second freewheels (3.11; 3.21) and the axis of the drive shaft (41) of the electric motor (4) form longitudinal edges of a prism with a triangular base.

Images