Field of the invention

The present invention relates to a method of strapping one or more articles with a strap, a strapping device and a strapping system .

Background of the invention

Strapping devices are used for packing various articles by placing a strap around the articles such that at least two portions of the strap overlap each other by forming a loop around the articles . Thereby, an end portion of the strap usually comprises a lower strap portion overlapping with another section of the strap forming an upper strap portion . The overlapping lower and upper portions of the strap are connected to each other by a strapping device which is applied to tension the strap and to j oin the overlapping portions of the strap . Various j oining techniques can be used for j oining the overlapping portion, such as for example welding, crimping, gluing etc . , the speci fic technique depending on the articles to be strapped and/or the material of the strap . Friction welding for example , is advantageously used for plastic straps , whereas additional clamps may be used for j oining metal straps .

The process of tensioning the strap placed around the articles , j oining the overlapping portions of the strap using the strapping device and releasing the strapping device from the tensioned and j oined strap loop, involves various operating elements of the strapping device which are to be designed to optimi ze the packaging of the one or more articles .

For example , EP 0 949 146 Al describes a strapping device where a plastic strip is placed in a loop around a package with a first , free end of the plastic strip forming a lower strip at a welding point and the other end of the plastic strip, as upper strip, being guided through together with the lower strip under a welding plate after formation of the loop at the welding point . The upper strip is then gripped by way of a friction wheel or a similar element , and the loop is tightened around the package . At the other end o f the loop, the end of the plastic strip is then guided as upper strip over the free end of the plastic strip as lower strip . The plastic strip is wound tightly around the package and is pressed together in this state at a point , at which the lower strip and upper strip run parallel to one another . A welding plate is then lowered at the welding point onto said upper strip which is free of tensile force , and said welding plate is vibrated with respect to the housing of the tightening strap device . At the same time , the welding plate presses the upper strip against the lower strip, with the result that a relative movement between the upper strip and the lower strip occurs on account of the vibration of the welding plate and the upper strip, which relative movement leads to local melting of the heat-weldable plastic strip on account of the friction which is produced in the process . After ending of the vibration movement and a brief time period o f cooling, the upper strip and lower strip are then welded to one another at the welding point . The clamping apparatuses which are present on both sides of the welding point for the lower strip or for the upper and lower strips can then be opened .

Summary of the invention

It is therefore an obj ect of the invention to provide a strapping device which at least partially improves the prior art and avoids at least part o f the disadvantages of the prior art .

According to the present invention, this obj ect 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 .

According to an aspect of the invention, this obj ect is particularly achieved by a method of strapping one or more articles with a strap, comprising the steps of : providing a strapping device comprising a j oining apparatus with a j oining j aw and a j oining base ; placing an end portion of the strap around the j oining base such that a fastening loop around the j oining base is formed; j oining overlapping first and second strap segments of the fastening loop by the j oining apparatus to form a strap j oint ; placing the strap around the one or more articles such that a third strap segment overlaps a segment of the fastening loop ; tensioning the strap around the one or more articles ; j oining the third segment of the strap with the segment of the fastening loop by the j oining apparatus ; shearing the tensioned strap of f from an untensioned bulk portion of the strap ; separating the strapping device from the tensioned strap by removing the j oining base from the fastening loop .

By forming a fastening loop around the j oining base , the end portion of the strap can be retained while tensioning the strap . In particular, additional parts for retaining the end portion of the strap, such as additional clamps , may be reduced or avoided, as the fastening loop is secured by the strap itsel f by j oining overlapping first and second strap segments of the fastening loop . Preferably, the fastening loop is closely placed around the j oining base such that the fastening loop lies against the j oining base . In the context of the present disclosure , placing an end portion of the strap around the j oining base or forming a fastening loop around the j oining base , respectively, shall be understood by the skilled person that the end portion of the strap or the fastening loop is placed or formed, respectively, around at least a portion of the j oining base . The fastening loop provides the advantage that a segment thereof can be used for j oining with a third segment of the strap to secure the strap tensioned around the one or more articles . In some embodiments , the segment of the fastening loop being j oined with the third segment may be the strap j oint or a segment adj acent to the strap j oint .

Thus , the method provides the advantage that the strap itsel f by an elaborate arrangement of the strap placing di f ferent strap segments in a useful relation to each other, can be used for retaining of the end portion of the strap while placing and tensioning of the strap around the one or more articles and for securing the strap tensioned around the one or more articles .

In some embodiments , the first and second strap segments , and the segment of the fastening loop and the third strap segment are j oined by welding, preferably friction welding .

For a strapping device with the j oining apparatus being a welder, the j oining j aw may therefore be a welding j aw and the j oining base may be a welding base .

In some embodiments , placing an end portion of the strap around the j oining base such that a fastening loop around the j oining base is formed comprises placing the first strap segment on an upper toothed surface of the j oining base and the second strap segment on the first strap segment .

Placing the first strap segment on the upper toothed surface of the j oining base provides the advantage that the first strap segment can be held while j oining of the first strap segment and the second strap segment . In particular, undesirable movement of the first strap segment , e . g . movement transverse to the strap axis , may be reduced or avoided by the upper toothed surface . In the context of the present disclosure , a toothed surface shall be understood by the skilled person as a surface with a structure which increases the friction between the surface and the strap . By holding the first strap segment , relative movement of the second strap segment with respect to the first strap segment while j oining, especially welding, can be enabled . Further, the upper toothed surface provides the advantage that the segment of the fastening loop can be held while j oining of the segment of the fastening loop and the third strap segment. Similar as for the first strap segment, undesirable movement of the segment of the fastening loop, e.g. movement transverse to the strap axis, may be reduced or avoided. By holding the segment of the fastening loop, relative movement of the third strap segment with respect to the segment of the fastening loop while joining, especially welding, can be enabled .

In some embodiments, a strap portion adjacent to the third strap segment is clamped by a clamp while joining the third segment of the strap and the segment of the fastening loop by the joining apparatus.

The clamp may particularly be advantageous for applications where high tensioning forces are used.

In some embodiments, providing the strapping device comprising a joining apparatus with a joining jaw and a joining base comprises providing an exchangeable joining base .

By providing an exchangeable joining base, the joining apparatus can be adapted to different strapping requirements. For example, a joining base with a larger vertical diameter may be provided in order to adjust the joining height, in particular, the welding height of the joining apparatus.

In some embodiments, providing the strapping device comprising a joining apparatus with a joining jaw and a joining base comprises providing a modular joining base with a base body, preferably a base plate, and a spacer arranged between the base body and the joining jaw and releasably connected to the base body.

By providing a modular joining base, adaptability of the joining apparatus to different strapping requirements can be improved. A spacer with specific features, such as for example a specific geometry, may be exchanged with another spacer with different features for different strapping situations. For example, a spacer with a larger upper toothed surface may be provided for improving the holding of the first strap segment. The spacer may therefore be adapted to the specific strap used. In a further example, a spacer with a larger vertical diameter may be provided in order to adjust the joining height, in particular, the welding height of the joining apparatus.

In some embodiments, a blade of a cutter of the strapping device for shearing the tensioned strap off from an untensioned bulk portion of the strap is moved relative to the joining jaw to a retracted inactive position before the step of joining overlapping first and second strap segments of the fastening loop by the joining apparatus to form a strap joint.

According to a further aspect, the present invention is also directed to a strapping device for strapping one or more articles with a strap according to the method as described in the present disclosure, the strapping device comprising a joining apparatus with a joining jaw and a joining base, the joining base comprising an upper toothed surface configured to engage with a first strap segment of a fastening loop placed around the joining base. As described above, the upper toothed surface of the joining base provides the advantage that the first strap segment can be held while joining of the first strap segment and the second strap segment when forming the fastening loop around the joining base. Further, the upper toothed surface provides the advantage that the segment of the fastening loop can be held while joining of the segment of the fastening loop and the third strap segment.

In some embodiments, the joining base comprises a base body, preferably a base plate, and a spacer arranged between the base body and the joining jaw and releasably connectable to the base body.

Thus, a modular joining base, as described above, can be provided, thereby improving adaptability of the joining apparatus to different strapping requirements.

The spacer may be releasably connectable to the base body by a form-fit and/or a force-fit connection. For example, the spacer may be connectable to the base body by a screw joint or by one or more suitable shoulders and/or legs and/or recesses of the spacer and/or of the base body.

In some embodiments, the upper toothed surface is arranged at the spacer.

In particular, an upper surface of the spacer facing towards the joining jaw may comprise the upper toothed surface.

Preferably, the spacer is made of metal. In some embodiments, the spacer is made of ceramics. In some embodiments , the spacer comprises an upper bar and the base body comprises at least one shoulder configured to laterally position the spacer .

The spacer may therefore be placed onto the base body, such that the upper bar is arranged between the base body and the j oining j aw . The upper bar may comprise an upper surface with the upper toothed surface . The vertical diameter of the upper bar may advantageously be adapted to achieve a required j oining height , in particular, welding height . The at least one shoulder provides the advantage of improved positioning of the spacer, especially during j oining of the di f ferent strap segments and during tensioning of the strap . Further, the shoulder allows to remove the spacer together with the base body after j oining the third segment of the strap with the segment of the fastening loop and shearing the tensioned strap of f from the untensioned bulk portion of the strap . One of the at least one shoulder is therefore preferably arranged to abut the base body on a side facing away from the direction of removal of the j oining apparatus from the tensioned strap .

In some embodiments , the base body comprises two shoulders , wherein the upper bar is receivable between the two shoulders .

In some embodiments , the upper bar is receivable between a shoulder of the base body and a vertical wall portion of the j oining apparatus .

In some embodiments , the upper bar comprises at least one recess which is engageable with the at least one shoulder . The at least one recess provides the advantage that the lateral positioning of the spacer can be improved.

In some embodiments, the spacer comprises a front leg and a rear leg connected by an upper bar, wherein the front leg, rear leg and upper bar are arranged to form a laterally open arch for receiving the base body.

The arch-shape provides the advantage that the spacer can be retained in position with respect to the direction along the strap axis.

In some embodiments, the joining base is releasably mounted at a mounting interface of the strapping device.

The joining base may be releasably mounted at the mounting interface by a form-fit and/or force-fit connection. For example, the joining base may be mounted at the mounting interface by a screw joint.

Therefore, an exchangeable joining base can be provided, such that the joining apparatus can be adapted to different strapping requirements, as described above.

In some embodiments, the strapping device comprises a cutter for shearing the strap, wherein the cutter comprises a blade which is movable relative to the joining jaw between an advanced active position and a retracted inactive position.

By providing a blade which is movable relative to the joining jaw, the cutter can selectively be activated or inactivated. Typically, the strap is sheared by the blade at a position next to where the overlapping strap portions are joined for the completed loop around the articles . Shearing of the strap may thereby be performed while the overlapping strap portions are being j oined exploiting the reciprocating movement of the j oining j aw and a suitable position of the blade contacting the strap .

Selectively inactivating the cutter by retracting the blade with respect to the j oining j aw provides the advantage that overlapping first and second strap segments of the fastening loop may be j oined without the strap being sheared at a proximate position . Preferably, the blade may be movable in an at least substantially vertical direction with respect to the j oining base .

After j oining overlapping first and second strap segments of the fastening loop, forming of a loop around the articles to be strapped may be continued . After completion of the loop, the cutter may be activated by advancing the blade relative to the j oining j aw to the active position such that the strap may be sheared while the third segment of the strap may be j oined with the segment of the fastening loop for the completed loop around the articles .

The blade may therefore be moved from an advanced active position where the blade may contact the strap to be sheared to a retracted inactive position with a greater distance to the j oining j aw and where the blade may not contact the strap even i f the strap is undergoing a j oining process by the j oining j aw .

In some embodiments , the cutter is simultaneously movable with the j oining j aw relative to the j oining base between an advanced joining position and a retracted strap receiving position .

In particular, the cutter may be fixedly connected to the joining jaw in order to enable simultaneous lowering and raising of the cutter with the joining jaw. While the cutter as a whole may be simultaneously movable with the joining jaw, the blade may be movable relative to the joining jaw, as described above.

In the joining position of the joining jaw, overlapping portions of the strap may be joined with each other. In case shearing of the strap while joining is desired, the blade of the cutter may be advanced to the active position. If shearing of the strap while joining is to be avoided, the blade of the cutter may be retracted to the inactive position. In the retracted strap receiving position of the joining jaw, the strap may be received or introduced, respectively, between the joining jaw and the joining base.

In some embodiments, the cutter comprises a follower which is fixedly arranged with respect to the blade and an actuating element with a cam, wherein the actuating element is configured to engage the cam with the follower to move the blade relative to the joining jaw between the advanced active position and the retracted inactive position.

The actuating element thus provides the advantage of an operating device by which the blade can be moved relative to the joining jaw by means of the cam engaging with the follower of the cutter owing to the fixed arrangement of the follower with respect to the blade . The cam may be a linear cam or a rotating cam, as will be described further below .

In some embodiments , the actuating element is biased against a cam spring such that the cam is movable against a bias force of the cam spring in a direction to raise or a direction to lower the blade relative to the j oining j aw .

The cam spring provides the advantage that active actuation of the actuating element and the cam, respectively, may be required only in one direction . For example , the actuating element may actively be actuated against the cam spring in a direction where the blade may be raised relative to the j oining j aw . For lowering the blade , the actuating element may passively be actuated in the opposite direction exploiting the bias force of the cam spring . Alternatively, the cam spring may be configured that active actuation of the actuating element and the cam, respectively, is only required in the direction to lower the blade and raising the blade is passively achieved using the bias force of the cam spring .

In some embodiments , the follower is biased against a follower spring such that the follower is movable against a bias force of the follower spring in a direction to raise or a direction to lower the blade relative to the j oining j aw .

Similar to the cam spring, the follower spring provides the advantage that active actuation of the follower may be required only in one direction . For example , the follower may actively be actuated against the follower spring in a direction where the blade may be raised relative to the j oining j aw . For lowering the blade , the follower may passively be actuated in the opposite direction exploiting the bias force of the follower spring . Alternatively, the follower spring may be configured that active actuation of the follower is only required in the direction to lower the blade and raising the blade is passively achieved using the bias force of the follower spring .

The strapping device may comprise both a cam spring and a follower spring ef fectively biasing the movement of the blade in the same direction . Alternatively, the strapping device may comprise only a cam spring or only a follower spring .

In some embodiments , the strapping device comprises a catch configured to lock the actuating element in a raised or lowered position of the blade by engaging with the actuating element , preferably with a recess of the actuating element .

Using the catch, the blade can be locked in a raised or lowered position . The catch may be released from the engagement with the actuating element by a manual or driven handle or a releasing element of a tensioning unit of the strapping device . The catch may exhibit a profile configured to engage with a counter profile of the actuating element .

In some embodiments , the cam is a rotating cam with a noncircular and/or eccentric cam profile , wherein the actuating element is configured to rotate with the cam .

In particular, the actuating element and the rotating cam may be supported on a common rotating shaft . The cam may comprise a noncircular profile and/or be eccentrically mounted on the rotating shaft . Due to the noncircular profile and/or the eccentricity, the cam may raise or lower the blade by engaging with the follower by rotation of the actuating element and the cam, respectively . The actuating element may comprise a rotatable plate or disc with a lever extending from the plate or disc within the plane of the rotatable plate or disc .

In some embodiments , the strapping device comprises an actuating bolt , wherein the actuating element comprises a lever and the actuating bolt is configured to engage with the lever to rotate the actuating element .

The actuating bolt may be moved linearly, especially in order to engage with the lever of the actuating element in a pushing fashion . By advancing the actuating bolt , the lever of the actuating element may be pushed ef fecting a rotation of the actuating element . The actuating bolt may be driven or manually be moved .

In some embodiments , the actuating bolt may trigger a j oining operation while engaging with the lever and rotating the actuating element . In particular, the actuating bolt may trigger a lowering of the j oining j aw while engaging the lever . For example , the actuating bolt may activate an end switch for triggering a j oining operation while engaging with the lever . The actuating bolt may trigger the j oining operation when the lever is engaged such that the blade is in the retracted inactive position .

In some embodiments , the cam is a linear cam with a ramp facing towards the follower, wherein the actuating element is configured to linearly move the cam, preferably in a hori zontal direction .

In particular, the actuating element and the linear cam may be moved in a transverse direction with respect to the longitudinal strap axis . The ramp may engage with the follower in order to raise or lower the blade relative to the j oining aw upon linear movement of the linear cam . The actuating element may comprise a bar which may be linearly movable . The linear cam may be arranged at an end o f the bar . The bar may comprise a recess or a counter profile configured to engage with a catch or a profile of a catch for locking the actuating element .

In some embodiments , the strapping device comprises a stop element with one or more stop surfaces , wherein the actuating element comprises a stop pin configured to engage with the one or more stop surfaces to maintain the blade in the advanced active position and/or in the retracted inactive position .

In particular, the stop element may be spatially fixed with respect to the strapping device and neither move with the j oining j aw nor with the cutter . The stop element therefore provides the advantage that the actuating element may engage with the stop element and lock the blade in the active or the inactive position depending on the position of the j oining j aw between the j oining position and the strap receiving position or at the j oining position or the strap receiving position . The stop pin may engage with the one or more stop surfaces by abutting on the one or more stop surfaces . One or more of the one or more stop surfaces may be part of a protrusion and/or a recess.

According to a further aspect, the present invention is also directed to a strapping system comprising a strapping device as described in the present disclosure and a plurality of spacers with different geometries, preferably different vertical diameters and/or different upper toothed surface areas .

In some embodiments of the strapping system, the spacers each comprise an upper bar with a different vertical diameter.

In some embodiments of the strapping system, the spacers each comprise a front leg and a rear leg connected by an upper bar, wherein the front leg, rear leg and upper bar are arranged to form a laterally open arch for receiving the base body, wherein the spacers preferably each comprise a different vertical diameter of the upper bar.

According to a further aspect, the present invention is also directed to a strapping system comprising a strapping device as described in the present disclosure and a plurality of joining bases with different geometries, preferably different vertical diameters and/or different upper toothed surface areas .

Brief description of the drawings

The present invention will be explained in more detail, by way of exemplary embodiments, with reference to the schematic drawings, in which: Fig. la shows an illustration of an embodiment of the invention with a fastening loop placed around a joining base of a strapping device comprising a spacer;

Fig. lb shows the strapping device of Fig. la without strap;

Fig.2a shows an illustration of an embodiment of the invention with a fastening loop placed around an exchangeable joining base of a strapping device;

Fig.2b shows the strapping device of Fig.2a without strap;

Fig.3 shows a flow diagram of a sequence of steps of an embodiment of the method of strapping one or more articles with a strap.

Fig.4a-b show illustrations of an embodiment of a strapping device in a partial view with a blade of a cutter in an advanced active position and in a retracted inactive position;

Fig.5 shows a partial view of the cutter of Figure 4a and

4b;

Fig.6a-b show vertical cut views of the cutter along the line A-A shown in Figure 5;

Fig.7 shows a semitransparent perspective view of the cutter;

Fig.8 shows the strapping device where the joining aw is moved relative to the joining base into the advanced joining position; Fig.9 shows a perspective partial view of an embodiment of a cutter with a linear cam;

Fig.lOa-d show the cutter of Fig.9 with different positions of the actuating element and of the cutter.

Detailed description of exemplary embodiments

For some embodiments in the description of the Figures, same reference numerals may be used for corresponding parts of the embodiments .

Figure la shows an illustration of an embodiment of the invention in a partial view of a strapping device 1 at the region of the joining apparatus 1.0. The joining apparatus 1.0 comprises a joining jaw 1.1 which, in the shown embodiment, is a welding jaw and a modular joining base 1.2 which is a welding base in the shown embodiment. The welding base 1.2 comprises a base body 1.21 in the form of a base plate and a laterally open, arch-shaped spacer 1.22 receiving the base body 1.21. The base body 1.21 comprises a lateral shoulder 1.211 which engages with a recess 1.221 of the spacer 1.2. The spacer 1.22 is made of metal.

An end portion 10.4 of a strap 10 is placed around the joining base 1.2 such that a fastening loop 10.5 is formed. Thereby, a first strap segment 10.1 is arranged on an upper surface of the spacer 1.22 and a second strap segment 10.2 is arranged on the first strap segment 10.1 such that the first and second strap segments 10.1, 10.2 overlap. The overlapping first and second strap segments 10.1, 10.2 are joined by the joining apparatus 1.0 to form a strap joint and to secure the fastening loop 10.5. For the purpose of illustration, the first and second strap segments 10.1, 10.2 are separately shown in Fig. la and the strap joint is not explicitly indicated. However, the skilled person understands that the strap joint is formed by joining the overlapping portions of the first and second strap segments 10.1, 10.2. The end portion of the strap 10 being fastened to the joining base 1.2, the strap 10 is placed around one or more articles (not shown in Fig. la) such that a third strap segment 10.3 is placed above a segment of the fastening loop (or the strap joint, or the first and second strap segments 10.1, 10.2, respectively) . After tensioning of the strap 10 around the one or more articles, the third strap segment 10.3 is joined with a segment of the fastening loop by the joining apparatus 1.0. Subsequently, the strap tensioned around the one or more articles is sheared off from an untensioned bulk portion of the strap and the strapping device 1 is separated from the tensioned strap by removing the joining base 1.2 from the fastening loop 10.5.

Removing of the joining base 1.2 from the fastening loop 10.5 is achieved by moving the strapping device 1 in a direction transverse to the strap axis (e.g. in Fig. la into the plane of the drawing) . Due to the shoulder 1.211 of the base body 1.21, the spacer 1.22 is removed together with the base body 1.21 from the fastening loop 10.5. The fastening loop 10.5 is closely placed around the joining base 1.2 such that the fastening loop 10.5 lies against the joining base 1.2. However, the tolerance between the fastening loop 10.5 and the joining base 1.2 is sufficient to allow removing of the joining base 1.2 from the fastening loop 10.5.

Fig. lb shows the strapping device 1 of Fig. la without a strap. The spacer 1.22 comprises an upper toothed surface 1.226 configured to engage with the first strap segment of the fastening loop shown in Fig. la. The upper toothed surface 1.226 retains the first strap segment and allows relative movement of the second strap segment with respect to the first strap segment while joining the first and second strap segment to form a strap joint. Further, the upper toothed surface 1.226 retains the fastening loop 10.5 and allows relative movement of the third strap segment with respect to the fastening loop 10.5 such that the third strap segment can be joined with a segment of the fastening loop.

The spacer 1.22 comprises a front leg 1.222 and a second leg 1.223 which are connected by an upper bar 1.224, such that a laterally open arch receiving the base plate 1.21 is formed. The upper bar 1.224 serves to provide a sufficient height required for the operation of the joining jaw 1.1.

In a strapping system, spacers with different geometries, e.g. different vertical diameters of the upper bar, and/or different upper toothed surface areas may be used for the strapping device 1.

The strapping device 1 further comprises a blade apparatus 1.7 for shearing the tensioned strap off from a bulk portion of the strap.

The strapping device 1 further comprises a positioning pin 1.6 which engages into a recess 1.225 of the spacer 1.22. In some embodiments, the positioning pin may not engage into a recess of the spacer. In some embodiments, the positioning pin may be arranged at a distance to the spacer. In some embodiments, the strapping device may comprise two or more positioning pins. The positioning pin 1.6 serves as guiding element for a strap. The positioning pin 1.6 is retractable in an upward direction, i.e. in a direction away from the spacer 1.22. In particular, the positioning pin 1.6 may be retracted before removing the strapping device 1 from the fastening loop.

Figure 2a shows an illustration of an embodiment of the invention in a partial view of a strapping device 2 at the region of the joining apparatus 2.0. The joining apparatus 2.0 comprises a joining jaw (not shown in Fig.2a) and an exchangeable joining base 2.2. The joining base 2.2 is made of metal.

An end portion 10.4 of a strap 10 is placed around the joining base 2.2 such that a fastening loop 10.5 is formed. A first strap segment 10.1 is arranged on an upper surface of the joining base 2.2 and a second strap segment 10.2 is arranged on the first strap segment 10.1 such that the first and second strap segments 10.1, 10.2 overlap. The overlapping first and second strap segments 10.1, 10.2 are joined by the joining apparatus 2.0 to form a strap joint and to secure the fastening loop 10.5. Similar to the embodiment shown in Fig. la, the first and second strap segments 10.1, 10.2 are separately shown and the strap joint is not explicitly indicated. With the end portion of the strap 10 being fastened to the joining base 2.2, the strap 10 is placed around one or more articles (not shown in Fig.2a) such that a third strap segment 10.3 is placed on a segment of the fastening loop 10.5 (or the strap joint, or the first and second strap segments 10.1, 10.2, respectively) . After tensioning of the strap 10 around the one or more articles, the third strap segment 10.3 is joined with the segment of the fastening loop by the joining apparatus 2.0. Subsequently, the strap tensioned around the one or more articles is sheared off from an untensioned bulk portion of the strap.

The joining base 2.2 is removed from the fastening loop 10.5 by moving the strapping device 2 in a direction transverse to the strap axis (e.g. for Fig.2a into the drawing plane) . The fastening loop 10.5 is closely placed around the joining base 2.2 such that the fastening loop 10.5 lies against the joining base 2.2. However, the tolerance between the fastening loop 10.5 and the joining base 2.2 is sufficient to allow removing of the joining base 2.2 from the fastening loop 10.5.

The joining base 2.2 is for example releasably mounted at a mounting interface of the strapping device 2 by a screw joint, such that the joining base 2.2 may be removed from the fastening loop 10.5 together with the strapping device 2 by e.g. a movement transverse to the strap axis, while being releasable from the mounting interface of the strapping device 2 by releasing the screw joint.

Figure 2b shows the strapping device 2 of Fig.2a without a strap. The joining base 2.2 comprises an upper toothed surface 2.21 configured to engage with the first strap segment of the fastening loop shown in Fig.2a. The upper toothed surface 2.21 is configured to retain the first strap segment and allows relative movement of the second strap segment with respect to the first strap segment while joining the first and second strap segment to form a strap joint. The upper toothed surface 2.21 is further configured to retain the fastening loop and allows relative movement of the third strap segment with respect to the fastening loop while joining the third strap segment with a segment of the fastening loop. The joining base 2.2 is releasably mounted from below at a mounting interface 2.3 of the strapping device 2. In a strapping system, different joining bases with different geometries, e.g. different vertical diameters, and/or different upper toothed surface areas, may be used for the strapping device 2.

Figure 3 shows a flow diagram of a sequence of steps of an embodiment of the method of strapping one or more articles with a strap. A strapping device comprising a joining apparatus, for example as shown as in Figures la or 2a, is provided in step SI. In step S2, an end portion of the strap is placed around a joining base of the strapping device such that a fastening loop is formed. In step S3, overlapping first and second strap segments of the fastening loop are joined by the joining apparatus to form a strap joint and to secure the fastening loop. The strap is placed around the one or more articles such that a third strap segment overlaps a segment of the fastening loop in step S4. The strap is tensioned around the one or more articles in step S5. In step S6, the third segment of the strap is joined with the segment of the fastening loop by the joining apparatus. The tensioned strap is sheared off from a bulk portion of the strap in step S7. In step S8 , the strapping device is separated from the tensioned strap by removing the joining base from the fastening loop.

Figure 4a and 4b show illustrations of an embodiment of a strapping device 1 in a partial view. The strapping device 1 comprises a cutter 1.4 for shearing the strap with a blade 1.41 which is movable relative to the joining aw 1.1 in a substantially vertical direction with respect to the joining base 1.2. The joining base 1.2 corresponds to the embodiment as shown in Figure la. The cutter 1.4 is arranged in a rear position next to the joining jaw 1.1 with respect to the longitudinal axis of a strap introduced between the joining jaw 1.1 and the joining base 1.2 (not shown in Figure 4a and 4b) . The cutter 1.4 may therefore shear a strap at a position next to where overlapping strap portions are joined.

Figure 4a shows the blade 1.41 of the cutter 1.4 in an advanced active position whereas Figure 4b shows the blade 1.41 in a retracted inactive position. In both cases, the cutter 1.4 is shown in a retracted strap receiving position. The cutter 1.4 may be lowered together with the joining jaw 1.1 towards the joining base 1.2 to an advanced joining position. In the advanced joining position of the joining jaw 1.1, the cutter 1.4 may shear a strap while joining overlapping strap portions if the blade 1.41 is in the advanced active position. If the blade 1.41 is in the retracted inactive position, as shown in Figure 4b, the cutter 1.4 may be lowered together with the joining jaw 1.1 to the advanced joining position without the strap being sheared during a joining operation of the joining jaw 1.1.

The cutter 1.4 is fixedly connected to the joining jaw 1.1 via the connecting block 1.11 such that the cutter 1.4 as a whole may be movable together with the joining jaw 1.1. The blade 1.41, however, may be movable relative to the joining jaw 1.1 by a rotating actuating element 1.42. The actuating element 1.42 comprises a disc with a lever 1.421 extending from the disc within the plane of the disc. A linearly movable actuating bolt 1.43 is engageable with the lever 1.421 in order to rotate the actuating element 1.42. In Figure 4b, the actuating bolt 1.43 is advanced compared to the configuration in Figure 4a and pushes the lever 1.421 such that the actuating element 1.42 is rotated, thereby retracting the blade 1.41 to the retracted inactive position.

As can be seen in Figure 4b, the actuating element 1.42 is locked in a raised position of the blade 1.41 by a catch 1.47 engaging with a counter profile of the actuating element 1.42 in the form of a recess 1.422. The catch 1.47 may be disengaged from the recess 1.422 using by a manual or driven handle, e.g. of the tensioning unit of the strapping device 1 (not shown in Figure 4b) , in order to allow the actuating element 1.42 to rotate back to the position shown in Figure 4a and the blade 1.41 to be advanced to the active position.

Figure 5 shows a partial view of the cutter 1.4 of Figure 4a and 4b attached to the connecting block 1.11. The cutter 1.4 is connected to the joining jaw via the connecting block 1.11 and thereby movable together with the joining jaw. The blade 1.41 is slidably arranged with respect to the connecting block 1.11. The cutter 1.4 comprises a follower 1.45 which is fixedly arranged with respect to the blade 1.41 and biased against a follower spring 1.44. The follower 1.45 is movable against a bias force of the follower spring 1.44 in a direction to raise the blade 1.41 relative to the connecting block 1.11 and therefore, to the joining jaw. As described above, the actuating element 1.42 may be rotated by pushing and releasing the lever 1.421 by the actuating bolt 1.43.

Figure 6a and 6b show vertical cut views of the cutter 1.4 along the line A-A shown in Figure 5. The cutter 1.4 comprises a rotating cam 1.46 with a noncircular profile 1.461. The cam 1.46 is supported on a common rotating shaft as the actuating element and configured to be rotatable by the actuating element. Due to the noncircular profile, the cam 1.46 can raise or lower the blade 1.41 by engaging with the follower 1.45 by rotation of the cam 1.46.

In Figure 6a, the blade 1.41 is in an advanced active position with respect to the joining jaw and the connecting block 1.11. In Figure 6b, the actuating element has rotated the cam 1.46 such that the cam 1.46 pushes the follower 1.45 against the bias force of the follower spring 1.44 by means of the noncircular profile 1.461. The follower spring 1.44 is therefore compressed compared to the configuration shown in Figure 6a.

By raising the follower 1.45, the blade 1.41 is raised with respect to the joining jaw and the connecting block 1.11 and thus moved from the advanced active position of Figure 6a into the retracted inactive position of Figure 6b. By rotating the cam 1.46 back, the follower 1.45 can be lowered by the bias force of follower spring 1.44 and the blade 1.41 moved from the retracted inactive position of Figure 6b to the advanced active position of Figure 6a.

Figure 7 shows a semitransparent perspective view of the cutter 1.4 with the rotating element 1.42 being locked by the catch 1.47 in a retracted inactive position of the blade 1.41. The actuating element 1.42 is biased against a cam spring 1.462 such that the cam is movable against a bias force of the cam spring 1.462 in a direction to raise the blade 1.41 relative to the joining jaw.

Figure 8 shows the strapping device 1 where the joining jaw

1.1 is moved relative to the joining base 1.2 into the advanced joining position. The cutter 1.4 as a whole is also moved together with the joining jaw 1.1 towards the joining base 1.2 due to the fixed connection to the joining jaw 1.1 via the connecting block 1.11. The blade 1.41 is in the advanced active position and may therefore shear a strap while overlapping portions of the strap are being joined between the joining jaw 1.1 and the joining base 1.2. By retracting the blade 1.41 by pushing the actuating bolt 1.43 and rotating the actuating element 1.42, a joining operation of a strap between the joining jaw 1.1 and the joining base

1.2 may be performed without shearing the strap next to the joining jaw 1.1.

The lever 1.421 of the actuating element 1.42 has a sufficient length to be engageable with the actuating bolt 1.43 also in the advanced joining position of the joining jaw 1.1 where the cutter 1.4 as a whole is being lowered towards the joining base 1.2. The lever 1.421 is therefore configured to be engageable with the actuating bolt 1.43 both in the advanced joining position of the joining jaw 1.1 and the retracted strap receiving position of the joining jaw 1.1.

Figure 9 shows a perspective partial view of an embodiment of a cutter 1.4' with a linear cam 1.46' . The linear cam 1.46' comprises a ramp 1.461' facing towards the follower 1.45' . The ramp 1.461' may engage with the follower 1.45' and raise the blade 1.41' relative to the joining aw upon linear movement of the cam 1.46' by pushing the follower 1.45' against the bias force of the follower spring 1.44' . The actuating element 1.42' has a bar-like shape with the cam 1.46' being arranged at an end of the bar. The actuating element 1.42' and the cam 1.46' are linearly movable in a direction transverse to the longitudinal strap axis or parallel to the cutting edge of the blade 1.41' , respectively .

The actuating element 1.42' comprises a recess 1.422' into which a catch 1.47' may engage in order to lock the actuating element 1.42' in a position where the blade 1.41' is in the advanced active position. Next to the actuating element 1.42' , there is arranged a stop element 1.5' with stop surfaces with which a stop pin 1.463' of the actuating element 1.42' can engage to selectively maintain the blade 1.41' in the advanced active position or in the retracted inactive position.

Figure 10a and 10b show the cutter 1.4' with the blade 1.41' in the advanced active position (Figure 10a) and in the retracted inactive position (Figure 10b) . In Figure 10a, the catch 1.47' engages the recess 1.422' of the actuating element 1.42' such that the blade 1.41' is locked in the advanced active position. The stop element 1.5' comprises a first stop surface 1.51' and a second stop surface 1.52' with which the stop pin 1.463' of the cam 1.46' may engage, depending on the horizontal position of the actuating element 1.42' and the vertical position of the cutter 1.4' . The stop element 1.5' may therefore be spatially fixed with respect to the strapping device and neither move with the joining aw nor with the cutter 1.4' . In Figure 10b, the catch 1.47' which is supported against a catch spring 1.471' has disengaged from the actuating element 1.42' . The actuating element 1.42' is moved in a parallel direction to the cutting edge of the blade 1.41' such that the ramp 1.461' of the cam 1.46' engages with the follower 1.45' and pushed the follower 1.45' against the bias force of the follower spring 1.44, thereby raising the blade 1.41' to the retracted inactive position. The stop pin 1.463' engages with the second stop surface 1.52' of the stop element 1.5' such that the actuating element 1.42' can not be further transversally moved in the direction away from the blade 1.41' .

Figure 10c and lOd show the cutter 1.4' with different positions of the actuating element 1.42' where the cutter 1.4' has been moved together with the joining jaw (not shown in Figures 10c and lOd) into the advanced joining position. In Figure 10c, the stop pin 1.463' engages with the second stop surface 1.52' of the stop element 1.5' forming a recess to receive the stop pin 1.463' . Due to the engagement of the stop pin 1.463' with the second stop surface 1.52' , the blade 1.41' is locked in the retracted inactive position. The joining aw may therefore execute a joining operation without the strap being sheared by the blade 1.41' .

In Figure lOd, the stop pin 1.463' engages with the first stop surface 1.51' forming an abutting surface against which the stop pin 1.463' abuts. Due to the engagement of the stop pin 1.463' with the first stop surface 1.51' , the blade 1.41' is locked in the advanced active position. The blade 1.41' may therefore shear the strap during a joining operation of the joining jaw.