STRAPPING DEVICE

FIELD OF THE INVENTION

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

BACKGROUND OF THE INVENTION

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. Thereby, a free end portion of the strap usually overlaps with another section of the strap, wherein the free end portion forms a lower strap portion and the other section of the strap forms an upper strap portion. 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. 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. Friction welding for example, is advantageously used for plastic straps, whereas additional clamps may be used for joining metal straps.

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

For example, EP 0 949 146 A1 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 of the loop, that end of the plastic strip which is loaded with tensile force 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 of 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

While packing articles, it is desired to obtain stable strapping, in particular with a sufficiently tensioned strap, such that a reliable strapping around the articles may be achieved.

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.

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.

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 joining apparatus for joining two overlapping portions of the strap, the joining apparatus comprising a joining jaw and a joining base arranged to receive the two overlapping portions of the strap therebetween, wherein the joining base comprises a base body and a spacer releasably connectable with the base body, the spacer comprising at least one lower support surface for the one or more articles and at least one upper support surface for the strap, wherein the spacer is configured to be releasable from the base body when the two overlapping portions of the strap are joined.

Due to the lower support surface for the one or more articles and the upper support surface for the strap, the spacer can remain between the one or more articles and the strap after being released from the base body. In particular, the spacer may be held between the one or more articles and the strap by virtue of the tension applied to the strap by the strapping device. After tensioning of the strap and joining the two overlapping portions of the strap to form a tensioned loop around the one or more articles, the strapping device can therefore be removed from the joined strap portions and the one or more articles, while leaving behind the spacer released from the base body. In particular, the base body arranged between the overlapping portions of the strap and the one or more articles while tensioning the strap and joining the overlapping portions of the strap may be removed while leaving the spacer positioned between the strap and the one or more articles.

While tensioning the strap and joining the overlapping portions of the strap, one or more strap portions may rest against the at least one upper support surface. The spacer remaining between the strap and the one or more articles provides the advantage that a tension being established on the strap can be maintained, as the strap may remain essentially stationary while and/or after removing of the strapping device due to the at least one upper support surface which continues to support the one or more portions of the strap resting thereagainst. As the tensioning forces of the strap in the direction of the one or more articles are taken up by the spacer by means of the at least one upper support surface and can therefore be caused to not act on the base body, removal of the strapping device after the strapping operation can be facilitated.

Compared to the prior art, where removing the strapping device after tensioning the strap and joining overlapping strap portions between a joining jaw and a joining base to form a loop around one or more articles to be packed, reduces the tension of the strap due to a void arising from the joining base being removed together with the strapping device, the strapping device and, in particular, the spacer advantageously allows to maintain the tension in the strap after removing the strapping device and therefore to improve the reliability of the strapping. Loss of tension in the strap due to removing of the strapping device can therefore be prevented by virtue of the spacer.

Due to the at least one lower support surface of the spacer, direct contact of the base body, which may be made of a material larger hardness than the one or more articles, can be avoided, as the spacer lies against the one or more articles. By choosing a suitable material for the spacer, preferably with a comparable or lower hardness than the one or more articles, the surface of the one or more articles can be protected from damage.

Further, the exchangeability of the spacer advantageously allows to adapt the geometry of the spacer for specific strapping requirements without having to modify the strapping device. For example, the geometry of the spacer may be adapted depending on the one or more articles to be strapped, as described further below. The geometry of the spacer may for example be adapted depending on the size of the one or more articles. Further, the geometry of the spacer may be adapted to optimize force transmission arising from tensioning of the strap. The spacer therefore provides the advantage of a simple, flexible and adaptable tension maintaining device.

Due to maintaining of the tension in the strap by virtue of the spacer, the strapping device may operate with smaller tensioning forces. In particular, the strapping device may, in certain applications, be used without separate clamp for clamping a portion of the strap adjacent to the upper of the overlapping portions of the strap while joining. Instead, holding said portion of the strap by means of the joining jaw while joining may be sufficient due to the low decrease of the tension in the strap and the smaller tensioning forces applied during operation of the strapping device.

The base body of the joining base may, in some embodiments, comprise a base plate. In some embodiments, the base body of the joining base may comprise pins or bolts, in particular, two cylindrical pins arranged in parallel to each other.

In some embodiments, the joining apparatus is a welder, preferably a friction welder.

For a strapping device with the joining apparatus being a welder, the joining jaw may therefore be a welding jaw and the joining base a welding base. The base body of the welding base may be a welding plate. Accordingly, the spacer advantageously allows to maintain the tension in the strap after removing the strapping device and, in particular, the welding base from between the welded overlapping portions of the strap and the one or more articles.

In some embodiments, the spacer is configured to be releasable from the base body in a horizontal direction transverse to a longitudinal strap axis.

Releasing the spacer transverse to a longitudinal strap axis may particularly be advantageous for small packages where the strap falls off from the joining base along the longitudinal strap axis. In some embodiments, however, the spacer may be configured to be releasable from the base body in a direction along a longitudinal strap axis. The person skilled in the art understands that “transverse” in this context does not have to be restricted to a direction strictly perpendicular to the longitudinal strap axis.

In some embodiments, the spacer is releasably connectable with the base body by a form-fit and/or a force-fit connection.

In particular, the spacer may be connected to the base body by a user of the strapping device before strapping the one or more articles and be removed from the base body after strapping without applying excessive force.

In some embodiments, the base body and the spacer are releasably connectable by a dovetail connection.

In some embodiments, the spacer is made of plastic.

Producing the spacer from plastic provides the advantage of reducing manufacturing costs. A spacer made of plastic may provide the advantage that the shape of the spacer may be manufactured to be adapted to one or more particular articles to be strapped in a simple fashion. A spacer made of plastic may particularly have the advantage of preventing the surface of the one or more articles from damage even for high tension applied to the strap. Further, using a spacer made of plastic provides the advantage that the spacer may be used for joining, in particular, welding one or more portions of the strap onto the spacer, as described further below. A spacer made of plastic may further be advantageous, as the spacer may be connected to the base body by a snap-fit connection due to the resilience of the plastic.

In some embodiments, the spacer comprises a concave profile formed on a lower side facing away from the base body.

The concave profile of the spacer provides the advantage that the transmission of forces arising from tensioning of the strap can be optimized. Preferably, the profile of the spacer is concave along a longitudinal axis of the spacer oriented along the longitudinal axis of the strap. Concave in the present context shall be understood to also comprise profiles with kinks or buckles. The concave profile does therefore not have to be a continuously smooth profile. However, the concave profile may be, in some embodiments, a continuously smooth, curved profile. The concave profile along the longitudinal axis of the spacer can be used to facilitate that the spacer abuts the one or more articles at a front and/or a rear portion of the spacer with respect to the longitudinal axis of the spacer, i.e. the at least one lower support surface may be arranged at the front and/or rear portion of the spacer. Further, a central portion of the spacer may be prevented from abutting the one or more articles. The concave profile may be particularly advantageous for a spacer where the at least one upper support surface is arranged at a front and/or a rear portion of the spacer, as the forces arising from tensioning of the strap may be taken up by the at least upper support surface at a front and/or rear portion and be guided to the at least one lower support surface arranged also at a front and/or rear portion of the spacer. In doing so, the spacer can advantageously be loaded predominantly by pressure and not by flexure. The concave profile of the spacer therefore allows for an optimized distribution of the forces arising from tensioning of the strap.

In some embodiments, the concave profile has an arc shape.

In some embodiments, the concave profile has an arc shape with a radius of curvature between 5 to 50 mm, preferably between 10 and 25 mm.

In some embodiments, the spacer comprises at least one chamfer or at least one convex profile adjacent to the concave profile.

The at least one chamfer or at least one convex profile adjacent to the concave profile may serve as a lower support surface by which the spacer may lie against the one or more articles. A spacer comprising a central concave profile along the longitudinal axis of the spacer and two chamfers or convex profiles adjacent to the concave profile may provide the advantage of an optimized distribution of forces when the spacer lies against the one or more articles. In particular, the forces may better be guided in the direction of a front leg and/or a rear leg of the spacer due to the at least one chamfer or the at least one convex profile adjacent to the concave profile.

In some embodiments, the joining apparatus comprises a clamp configured to clamp a portion of the strap between the clamp and the spacer.

In some embodiments, the portion of the strap adjacent to the upper of the two overlapping portions of the strap can be clamped while joining of the two overlapping portions of the strap. In some embodiments, the portion of the strap adjacent to the lower of the two overlapping portions of the strap can be clamped while tensioning of the strap. In some embodiments, the clamp is arranged to clamp the portion of the strap between the clamp and one of the at least one upper support surface of the spacer. Further, the clamp provides the advantage that the size of the base body can be reduced compared to strapping devices where the strap is clamped between a clamp and the base body. The clamp may particularly be advantageous for applications where high tensioning forces are used.

In some embodiments, the joining apparatus comprises a clamp configured to clamp a portion of the strap between the clamp and a front leg or a rear leg of the spacer. In some embodiments, the leg comprising a surface on which the portion of the strap is clamped by the clamp may have a larger transverse diameter than the other leg.

In some embodiments, the base body exhibits a tolerance with respect to the spacer along the longitudinal strap axis.

The tolerance may allow to mount and/or release the spacer more easily to/from the base body. The tolerance may be used for receiving a portion of the strap between the spacer and the base body. In some embodiments, receiving a portion of the strap between the spacer and the base body may be used for snap-fit connection of the spacer with the base body by means of a resilience of the strap.

In some embodiments, the spacer comprises a front leg and a rear leg connected by a lower bar, wherein the front leg, rear leg and lower bar are arranged to form a trough for receiving the base body.

The spacer may therefore exhibit a C-like shape. The front leg may comprise a first upper support surface for the strap and the rear leg may comprise a second upper support surface for the strap. The front leg and/or the lower bar, respectively, may further comprise a lower surface serving as a first lower support surface for the one or more articles. The rear leg and/or the lower bar, respectively, may further comprise a lower surface serving as a second lower support surface for the one or more articles. The lower bar may comprise a concave profile on a surface facing away from the joining jaw. The lower surfaces of the front leg and/or the rear leg and/or the lower bar, respectively, may comprise a chamfer or a convex profile.

In some embodiments, the joining base comprises a gap between the base body and the spacer configured to receive a portion of the strap such that the portion of the strap is placeable around at least a part of the base body.

Placing a portion of the strap around at least a part of the base body provides the advantage that the lower portion of the overlapping portions of the strap can be held while tensioning the strap. In particular, the lower portion of the overlapping portions of the strap may be held without the need of an additional clamp to hold the lower portion of the overlapping portions.

For a C-shaped spacer for example, the portion of the strap may be placed between the lower bar and the base body, and between the front leg and the base body. By placing the strap in this fashion, the base body may be pressed against the rear leg due to the resilience of the strap, such that the spacer can be connected with the base body in a snap-fit fashion. The gap may thus be arranged between the front leg and the base body and between the lower bar and the base body when the spacer is connected to the base body.

In some embodiments, the base body comprises a toothing configured to frictionally engage with a portion of the strap placed around the at least a part of the base body or with a portion of the spacer. The toothing may be arranged at a front part of the base body facing towards the front leg of the spacer and/or at a lower part of the base body facing towards the lower bar of the spacer and/or at an upper part of the base body facing towards the joining jaw or an upper bar of the spacer. The toothing or toothed surface may be any structure which increases the friction between the base body and the strap or between the base body and the spacer.

In some embodiments, the spacer comprises a shoulder, wherein the gap between the base body and the spacer is shaped to receive the portion of the strap in a manner that the base body is engaged with the shoulder by a resilience of the portion of the strap.

In particular, the base body may be pressed against the shoulder by a resilience of the portion of the strap.

In some embodiments, the front leg and/or the rear leg comprises an undercut.

The undercut may be used for connecting the spacer with the base body. For example, the undercut may be used to connect the spacer to the base body by a snap-fit connection.

In some embodiments, the front leg and/or the rear leg comprises a protrusion engageable with a recess of the base body or the front leg and/or the rear leg comprises a recess engageable with a protrusion of the base body.

The protrusions and/or recesses of the spacer and/or the base body may be used for connecting the spacer with the base body.

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 spacer may therefore be placed on the base body, such that the upper bar is arranged between the base body and the joining jaw. For releasing the spacer from the base body, the base body may be moved downwards with respect to the spacer and removed laterally. The upper bar may comprise an upper surface serving as an upper support surface for the strap. The front leg and the rear leg may comprise lower surfaces serving g as lower support surfaces for the one or more articles.

In some embodiments, the front leg and rear leg are further connected by a lower bar, wherein the front leg, rear leg, lower bar and upper bar are arranged to form a laterally open hollow for receiving the base body.

The lower bar provides the advantage that the stability of the spacer can be increased. The lower bar may comprise a lower support surface for the strap. Further, the lower bar may comprise a concave profile at a lower surface facing away from the joining jaw.

In some embodiments, the upper bar comprises a joining surface facing towards the joining jaw, wherein the joining apparatus is configured to join a portion of the strap to the joining surface of the upper bar.

For strapping devices comprising a welder as a joining apparatus, the joining surface of the upper bar may be a welding surface. By joining a portion of the strap, preferably the lower of the two overlapping portions of the strap to be joined, the strap can be held while tensioning of the strap. A separate clamp for holding a portion of the strap adjacent to the lower of the overlapping portions of the strap while tensioning may therefore not be required. Joining a portion of the strap with the joining surface of the upper bar provides the further advantage of an increased stability of the joined strap and the packed one or more articles. For example, laterally slipping out of the spacer can be prevented, as the spacer is joined with the strap.

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. Shearing of the strap may thereby be performed while the overlapping strap portions are being joined exploiting the reciprocating movement of the joining jaw and a suitable position of the blade contacting the strap.

Selectively inactivating the cutter by retracting the blade with respect to the joining jaw provides the advantage that a portion of the strap may be joined to the joining surface of the upper bar of the spacer 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 joining base or the joining surface.

After joining a portion of the strap to the joining surface of the upper bar, 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 joining jaw to the active position such that the strap may be sheared while overlapping portions of the strap may be joined. For some uses, it may be advantageous to retract the blade with respect to the joining jaw in order to join overlapping portions of the strap without the strap being sheared at a proximate position.

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 joining jaw and where the blade may not contact the strap even if the strap is undergoing a joining process by the joining jaw.

In some embodiments, the cutter is simultaneously movable with the joining jaw relative to the joining 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 or a portion of the strap to the joining surface of the spacer. 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, for example if a portion of the strap is joined to the joining surface of the spacer, 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 joining jaw.

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 joining jaw. 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 joining jaw.

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 joining jaw. 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 effectively 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 effecting 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 joining operation while engaging with the lever and rotating the actuating element. In particular, the actuating bolt may trigger a lowering of the joining jaw while engaging the lever. For example, the actuating bolt may activate an end switch for triggering a joining operation while engaging with the lever. The actuating bolt may trigger the joining 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 horizontal 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 joining jaw 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 of 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 joining jaw 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 joining jaw between the joining position and the strap receiving position or at the joining 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.

In some embodiments, the base body comprises one or more lateral shoulders, wherein the one or more shoulders are configured to laterally position the upper bar.

The one or more lateral shoulders provide the advantage of improved positioning of the spacer, especially during tensioning and joining of the strap.

In some embodiments, the upper bar comprises one or more recesses engageable with the one or more lateral shoulders of the base body.

In some embodiments, the spacer comprises a slot configured to receive and fasten an end portion of the strap.

The end portion of the strap may be folded over and inserted into the slot, such that the strap may be pinched in the slot while tensioning of the strap. The end portion fastened at the slot is preferably adjacent to the lower of the overlapping portions of the strap.

In some embodiments, the spacer comprises a wedge insertable into the slot to fasten the end portion of the strap by a force-fit connection.

The end portion may be folded around the wedge and inserted together with the wedge into the slot. By tensioning the strap, the end portion and the wedge may be pinched in the slot.

In some embodiments, the strapping device comprises a plurality of spacers according to the present disclosure.

Using a plurality of spacers provides the advantage of improved adaptability to the one or more articles to be strapped. The plurality of spacers may, in some embodiments, each comprise a different shape in order to better adapt to the one or more articles to be strapped.

In particular, the strapping device may comprise two, three or four spacers.

According to a further aspect, the present invention is also directed to a method of operating a strapping device for strapping one or more articles as described in the present disclosure, the method comprising the steps of: placing a strap around the one or more articles; connecting the spacer with the base body; fastening an end portion of the strap at the spacer; tensioning the strap around the one or more articles and the spacer; joining two overlapping portions of the strap positioned between the joining jaw and the joining base; shearing the tensioned strap off from an untensioned bulk portion of the strap; separating the strapping device from the strap tensioned around the one or more articles and the spacer by releasing the spacer from the base body such that the spacer remains between the one or more articles and the tensioned strap.

The person skilled in the art understands that the steps in the above method may be changed in order. For example, placing the strap around the one or more articles may be executed after fastening an end portion of the strap at the spacer. Fastening an end portion of the strap at the spacer may comprise among others placing the end portion around the base plate connected with the spacer or joining the end portion of the strap to the spacer.

In some embodiments of the method, a plurality of spacers is used for strapping the one or more articles. The plurality of spacers may be positioned at different positions along the strap placed or to be placed around the one or more articles. Therefore, additional to the step of fastening an end portion of the strap at a first spacer, one or more additional spacers may be fastened at different positions along the strap.

According to a further aspect, the present invention is also directed to a spacer for a strapping device according to the present disclosure, comprising at least one lower support surface for the one or more articles and at least one upper support surface for the strap, wherein the spacer is configured to be releasably connectable with the base body and to be releasable from the base body when the two overlapping portions of the strap are joined.

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. 1a shows an illustration of a prior art strapping device while strapping an article;

FIG. 1b shows the article after removing of the strapping device of FIG. 1a;

FIG. 2a shows an illustration of an embodiment of a strapping device while strapping an article with a spacer;

FIG. 2b shows the article after removing of the strapping device of FIG. 2a;

FIG. 3a shows an illustration of an embodiment of a spacer arranged between two articles;

FIG. 3b shows an illustration of an embodiment of a spacer arranged on top of an article;

FIG. 4 shows an illustration of an embodiment of a strapping device in a partial view;

FIG. 5a shows an illustration of an embodiment of a strapping device in a partial view before connecting the spacer to the base body;

FIG. 5b shows the strapping device of FIG. 5a after connecting the spacer to the base body;

FIG. 6a shows an illustration of an embodiment of a spacer in a cut view;

FIG. 6b shows an illustration of an embodiment of a spacer in a cut view;

FIG. 7 shows an illustration of an embodiment of a strapping device in a partial view;

FIG. 8 shows an illustration of an embodiment of a strapping device in a partial view;

FIG. 9 shows an illustration of an embodiment of a strapping device in a partial view;

FIG. 10a-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. 11 shows a partial view of the cutter of FIGS. 10a and 10b;

FIG. 12a-b show vertical cut views of the cutter along the line A-A shown in FIG. 11;

FIG. 13 shows a semitransparent perspective view of the cutter;

FIG. 14 shows the strapping device where the joining jaw is moved relative to the joining base into the advanced joining position;

FIG. 15 shows a perspective partial view of an embodiment of a cutter with a linear cam;

FIG. 16a-d show the cutter of FIG. 15 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.

FIG. 1a shows an illustration of a prior art strapping device 1 while strapping an article 20. The article 20 may also symbolize a plurality of articles. The strapping device 1 comprises a joining jaw 1.1 and a joining base 1.2 arranged to receive a strap 10 therebetween. The strapping device 1 further comprises a tensioning apparatus 1.3 with a tensioning wheel. The strap 10 is shown to be positioned around the article 20 to form a loop. Two overlapping portions of the strap 10 are arranged between the joining jaw 1.1 and the joining base 1.2 at a position P. The portions 10.1 of the strap 10 adjacent to the lower of the two overlapping portions of the strap 10 and the lower portion of the two overlapping portions of the strap 10 are termed lower strap. Accordingly, the portions 10.2 of the strap 10 adjacent to the upper of the two overlapping portions of the strap 10 and the upper portion of the two overlapping portions of the strap 10 are termed upper strap. The base body 1.2 as a whole is fixedly mounted in the strapping device 1. The terms “lower” and “upper” shall be understood with respect to the strapping device and the strap being in a typical working position. Typically, “upper” shall therefore be understood as being facing towards the strapping device and “lower” shall be understood as being facing towards the one or more articles to be strapped.

FIG. 1b shows the article 20 with the strap 10 after removing of the strapping device of Figure la. As the base body arranged between the overlapping portions of the strap and the article 20 during joining of the overlapping strap portions is removed, a void V is formed between the overlapping portions of the strap at position P and the article 20. Due to the tension in the strap 10, the void V collapses after removing of the base body, i.e. the overlapping portions of the strap 10 move towards the article 20, as indicated by the vertical arrow. Thereby, the tension in the strap 10 decreases, which decreases the reliability of the strapping.

FIG. 2a shows an illustration of an embodiment of a strapping device 2 while strapping an article 20. The article may also symbolize a plurality of articles, such as for example a plurality of pipes. Although the article 20 of FIG. 2a is denoted with the same numeral as in FIG. 1a, it is clear to the skilled person, that the articles are only symbolized in the Figures and may in fact be different articles. This may also apply to the other Figures of the present disclosure.

The strapping device 2 comprises a joining apparatus comprising a joining jaw 2.1 and a joining base 2.2. In the shown example, the joining apparatus is a friction welder, such that the joining jaw 2.1 is a welding jaw and the joining base 2.2 is a welding base. The joining base 2.2 comprises a base body 2.21 in the form of a base plate and a spacer 2.22 releasably connected to the base body 2.21 in a form-fit fashion by a dovetail connection. The base body 2.21 and the spacer 2.22 are releasably from each other in a direction transverse to the longitudinal strap axis, i.e. in a direction perpendicular to the plane of drawing. The spacer 2.22 exhibits a C-shape forming a trough for receiving the base body 2.21. The spacer 2.22 is made of plastic and is arranged between two overlapping portions of the strap 10 and the article 20. The two overlapping portions of the strap 10 are received between the joining jaw 2.1 and the base body 2.21 and can be joined by friction welding. The lower strap is partially placed around the spacer 2.22.

FIG. 2b shows the article 20 and the strap 10 after removing of the strapping device of FIG. 2a. Due to the spacer 2.22 being releasable from the base body, the spacer 2.22 remains between the strap 10, in particular the overlapping portions of the strap 10, and the article 20, after removing of the strapping device. Compared to the situation in FIG. 1b, there is no void between the overlapping portions of the strap 10 and the article 20, as the spacer 2.22 keeps the overlapping portions of the strap 10 stationary at the position P and therefore maintains the tension in the strap 10. The spacer 2.22 can therefore create space for the parts of the strapping device, such as the joining base and the base body, which are arranged between the article 20 and the strap 10 while strapping. Furthermore, the spacer can prevent said space from collapsing after removing of the strapping device, such that the tension in the strap 10 can be maintained. Thereby, loss of tension due to removing of the strapping device can be prevented.

As can be seen in FIG. 2b, the spacer 2.22 comprises a front leg 2.221 and a rear leg 2.222 which are connected by a lower bar 2.223. The terms “front” and “rear” shall be understood with respect to the longitudinal strap axis. The front leg 2.221, the rear leg 2.222 and the lower bar 2.223 are arranged to form a trough T for receiving the base body. The front leg 2.221 comprises an upper surface 2.224 serving as a first upper support surface for the strap 10 and a lower surface 2.226 serving as a first lower support surface for the article 20. The rear leg 2.222 comprises an upper surface 2.225 serving as a second upper support surface for the strap 10 and a lower surface 2.227 serving as a second lower support surface for the article 20. The lower bar 2.223 comprises a concave profile 2.228 in the shape of an arc at its lower side facing away from the trough T. Due to the arrangement of the first and second lower support surfaces 2.226, 2.227 and the concave profile 2.228, forces arising from tensioning of the strap 10 taken up by the first and second upper support surfaces 2.224, 2.225 can be guided to the first and second lower support surfaces 2.226, 2.227, such that the spacer 2.22 can predominantly be loaded by pressure and not by flexure, allowing for an optimized force distribution, as symbolized by the double arrows. The lower strap 10.1 is partially placed around the spacer 2.22. The upper strap 10.2 is arranged above the lower strap 10.1 at the position P where the upper strap 10.2 and the lower strap 10.1 are joined.

FIG. 3a shows an illustration of an embodiment of a spacer 3.22 arranged between two articles 20.1 and 20.2. In the shown example, the articles 20.1 and 20.2 are pipes. The spacer 3.22 comprises a front leg 3.221 and a rear leg 3.222 connected by a lower bar 3.223. The front leg 3.221 comprises a first upper support surface 3.224 and a first lower support surface 3.226. The rear leg 3.222 comprises a second upper support surface 3.225 and a second lower support surface 3.227. The lower bar 3.223 comprises a concave profile 3.228 in the shape of an arc at its lower side facing away from the trough formed by the front leg 3.221, rear leg 3.222 and the lower bar 3.223. The upper support surfaces 3.224 and 3.225 are laterally bordered by walls which improves holding of the spacer 3.22 while separating the strapping device from the tensioned strap by releasing the spacer 3.22 from the base body. The lateral walls may especially prevent the spacer 3.22 from laterally slipping out of the position between the one or more articles and the tensioned strap when the base body is released from the spacer 3.22 in a horizontal direction transverse to the longitudinal strap axis. The lateral walls may further improve positioning of a strap at the upper support surfaces 3.224 and 3.225. Further, the lateral walls may improve holding of the spacer 3.22 in place during transport of the one or more articles, as transverse forces may thereby act on the spacer. The rear leg 3.222 further comprises or protrusion 3.229, a shoulder respectively, engageable with a recess of the base body of a strapping device and giving rise to an undercut which may be used for snap-fit connection between the spacer 3.22 and the base body of a strapping device. The first and second lower support surfaces 3.226 and 3.227 exhibit a convex profile. In some embodiments, the first and/or second lower support surface 3.226, 3.227 may be chamfered. The spacer 3.22 is arranged between the articles 20.1 and 20.2, as the first and second lower support surfaces 3.226 and 3.227 lie against the articles 20.1 and 20.2, respectively. Such an arrangement is particularly advantageous for the radius of curvature of the concave profile 3.228 being larger than the radius of the curvature of the pipes 20.1 and 20.2.

FIG. 3b shows an illustration of an embodiment of a spacer 3.22′ arranged on top of an article 20.1′ shown as a pipe. The spacer 3.22′ has essentially the same shape as the spacer 3.22 shown in FIG. 3a. However, the radius of curvature of the concave profile 3.228′ of the lower bar 3.223′ may differ from the one of the spacer 3.22 of FIG. 3a. In the shown example, the spacer 3.22′ is arranged on top of an article 20.1′. Such an arrangement is particularly advantageous for the radius of curvature of the concave profile 3.228′ being smaller than the radius of curvature of the pipe 20.1′. Compared to FIG. 3a, the radius of curvature of the concave profile 3.228′ may be smaller or the radius of curvature of the article 20.1′ may be larger.

FIG. 4 shows an illustration of an embodiment of a strapping device 4 in a partial view at the region of the joining apparatus 4.0. The joining apparatus 4.0 comprises a welding jaw 4.1 and a welding base 4.2. The welding base 4.2 comprises a base plate 4.21 and a spacer 4.22 with a similar shape as the spacer 3.22 shown in FIG. 3a. The spacer 4.22 comprises a bore in the front leg 4.221 into which a pin 4.5 engages in order to connect the spacer with the base plate 4.21. The joining apparatus 4.0 further comprises a clamp 4.4 configured to clamp the upper strap portion 10.2 between the clamp 4.4 and the first upper support surface 4.224 while welding the overlapping portions of the lower strap 10.1 and the upper strap 10.2 between the welding jaw 4.1 and the base plate 4.21. The clamp 4.4 may optionally be used for improving the holding of the upper strap portion 10.2 while joining the overlapping strap portions, in particular, in applications where high tensioning forces are used. The base plate 4.21 exhibits a tolerance with respect to the spacer 4.22, especially along the longitudinal strap axis. The welding base 4.2 comprises a gap between the base plate 4.21 and the spacer 4.22 into which an end portion of the lower strap 10.1 is inserted such that the end portion of the lower strap 10.1 is placed around a part of the base plate 4.21 to lie along the top, front and bottom surface of the base plate 4.21. By placing the end portion of the lower strap 10.1 partially around the base plate 4.21, the strap 10 can be held while tensioning of the strap 10. The base plate 4.21 comprises teeth 4.211 at a front part of the base plate 4.21 which may frictionally engage with the portion of the lower strap 10.1 lying against the front part of the base plate 4.21 when the strap 10 is tensioned, which improves holding of the strap 10 while tensioning. The base plate 4.21 further comprises a recess 4.212 which may engage with a shoulder 4.229 of the spacer 4.22. In some embodiments without a pin 4.5, the recess 4.212 may engage with the shoulder 4.229 due to a resilience of the portion of the strap 10 received in the gap between the base plate 4.21 and the spacer 4.22.

Such an engagement between base plate and spacer is shown in FIGS. 5a and 5b. FIG. 5a an illustration of an embodiment of a strapping device 5 in a partial view before connecting the spacer 5.22 to the base plate 5.21. The recess 5.212 of the base plate 5.21 is not engaged with the shoulder 5.229 of the spacer 5.22. The recess 5.212 and the shoulder 5.229 comprise corresponding lateral chamfers in lateral direction which prevent releasing of an engagement between the recess 5.212 and the shoulder 5.229 in a specific lateral direction. In the shown example, the recess 5.212 comprises a lateral chamfer closing in the direction oriented towards the drawing plane, such that the spacer 5.22 is to be laterally released from the base plate 5.21 in the direction oriented away from the drawing plane or, the base plate 5.21 is to be laterally released from the spacer 5.22 in the direction oriented towards the drawing plane, respectively.

FIG. 5b shows the strapping device 5 of FIG. 5a after connecting the spacer 5.22 to the base plate 5.21. The recess 5.212 of the base plate 5.21 is engaged with the shoulder 5.229 using at least partially the resilience of an end portion 10.11 of the lower strap 10.1 placed partially around the base plate 5.21.

FIG. 6a shows an illustration of an embodiment of a spacer 6.22 comprising a slot 6.2210 configured to receive and fasten an end portion 10.11 of the lower strap 10.1. A wedge 6.2211 with the end portion 10.11 of the lower strap 10.1 placed around the wedge 6.211 is inserted into the slot 6.2210 of the spacer 6.22. By tensioning of the strap 10, the end portion 10.11 is fastened by the wedge 6.211 pinched into the slot 6.2210 in a force-fit fashion. The base plate 6.21 is dimensioned to leave a sufficient gap between the front part of the base plate and the front leg 6.221 of the spacer 6.22 such that the lower strap 10.1 can be guided from the wedge 6.2211 over the base plate 6.21 to the rear leg 6.222 of the spacer 6.22. The lower strap 10.1 may further hold the base plate 6.21 at a rear region of the trough of the spacer 6.22 while tensioning and joining of the strap 10.

FIG. 6b shows an illustration of an embodiment of a spacer 6.22′ comprising a slot 6.2210′ configured to receive and fasten an end portion 10.11 of the lower strap 10.1. The end portion 10.11 is folded over and inserted into the slot 6.2210′ without a wedge. The end portion 10.11 of the strap is pinched into the slot 6.2210′ while tensioning of the strap 10. Similar to FIG. 6a, the base body 6.21′ is dimensioned to leave sufficient place for the strap portion running within the trough of the spacer 6.22′. Further, the lower strap 10.1 may hold the base body 6.21′ at a rear region of the trough of the spacer 6.22′ while tensioning and joining of the strap 10.

FIG. 7 illustration of an embodiment of a shows an strapping device 7 in a partial view. The spacer 7.22 comprises a front leg 7.221 and a rear leg 7.222 connected by a lower bar 7.223 and an upper bar 7.2212. The front leg 7.221, the rear leg 7.222, the lower bar 7.223 and the upper bar 7.2212 are arranged to form a laterally open hollow H for receiving the base plate 7.21. The base plate 7.21 comprises a lateral shoulder 7.213. The upper bar 7.2212 is receivable between the shoulder 7.213 and a vertical side wall portion (hidden behind the spacer 7.22 in FIG. 7) of the joining apparatus, such that the shoulder 7.213 serves as lateral positioner for the upper bar 7.2212. The shoulder 7.213 engages into a recess 7.2213 formed in the upper bar 7.2212. The spacer 7.22 is therefore hanging on the base plate 7.21. In order to remove the base plate 7.21 after joining a strap to form a loop, the base plate 7.21 may be moved downwards with respect to the spacer 7.22, such that the shoulder 7.213 disengages with the upper bar 7.2212 and the recess 7.2213, and subsequently removed laterally from the hollow H. In some embodiments, the base plate may comprise two lateral shoulders with the upper bar of the spacer being receivable therebetween. Accordingly, the upper bar of the spacer may, in some embodiments, comprise two recesses engageable with the lateral shoulders. The strapping device 7 further comprises two positioning pins 7.6 which engage into recesses 7.2214 of the spacer 7.22. In some embodiments, the positioning pins may not engage into recesses of the spacer. In some embodiments, the positioning pins may be arranged at a distance to the spacer. The positioning pins 7.6 serve as guiding elements for a strap which may be guided to lie between the positioning pins 7.6 and on the upper surface 7.2215 of the upper bar 7.2212. The positioning pins 7.6 may further contribute to lateral positioning of the spacer 7.22. The upper surface 7.2215 may serve as a joining surface, especially a welding surface, where a portion of a strap may be joined, especially welded, onto said surface 7.2215. The positioning pins 7.6 can be retracted upwards, i.e. in a direction away from the spacer 7.22.

FIG. 8 shows an illustration of an embodiment of a strapping device 8 in a partial view. The spacer 8.22 has a shape corresponding to the spacer 7.22 shown in FIG. 7. However, the base plate 8.21 comprises instead of lateral shoulders a toothing or toothed surface 8.214 configured for engagement with a lower surface of the upper bar 8.2212 of the spacer 8.22. By means of a downward force exerted by the joining jaw, the upper bar 8.2212 is pressed onto the toothing 8.214 such that the spacer 8.22 can be fixed and, in particular, lateral movement of the spacer 8.22 can be prevented.

FIG. 9 shows an illustration of an embodiment of a strapping device 9 in a partial view. The spacer 9.22 comprises a front leg 9.221 and a rear leg 9.222 connected by an upper bar 9.2212. The front leg 9.221, the rear leg 9.222 and the upper bar 9.2212 are arranged to form a laterally open arch for receiving the base plate 9.21. The base plate 9.21 comprises a lateral shoulder 9.213 for positioning of the spacer 9.22. The lateral shoulder 9.213 engages into a recess 9.2213 formed in the upper bar 9.2212 The spacer 9.22 is further positioned by positioning pins 9.6 which also serve for guiding a strap. The positioning pins 9.6 are retractable in a direction away from the spacer 9.22. The upper bar 9.2212 comprises on its upper surface a joining surface 9.2215 where a portion of a strap may be joined, especially welded, onto said surface 9.2215. The front leg 9.221 and the rear leg 9.222 project vertically beyond the base plate 9.21 and thereby provide a first lower support surface 9.226 and a second lower support surface 9.227 for the one or more articles. Furthermore, owing to the front leg 9.221 and the rear leg 9.222 projecting vertically beyond the base plate 9.21, the base plate 9.21 may be moved downwards with respect to the spacer 9.22 for releasing the spacer 9.22 from the base plate 9.21 after tensioning and joining of the strap.

FIGS. 10a and 10b 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 jaw 1.1 in a substantially vertical direction with respect to the joining base 1.2. The joining base 1.2 comprises a base plate and a spacer corresponding to the embodiment as shown in FIG. 7. 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 FIGS. 10a and 10b). The cutter 1.4 may therefore shear a strap at a position next to where overlapping strap portions are joined.

FIG. 10a shows the blade 1.41 of the cutter 1.4 in an advanced active position whereas FIG. 10b 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 in is the retracted inactive position, as shown in FIG. 10b, 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 FIG. 10b, the actuating bolt 1.43 is advanced compared to the configuration in FIG. 10a 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 FIG. 10b, 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 FIG. 10b), in order to allow the actuating element 1.42 to rotate back to the position shown in FIG. 10a and the blade 1.41 to be advanced to the active position.

FIG. 11 shows a partial view of the cutter 1.4 of FIGS. 10a and 10b 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.

FIGS. 12a and 12b show vertical cut views of the cutter 1.4 along the line A-A shown in FIG. 11. 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 FIG. 12a, the blade 1.41 is in an advanced active position with respect to the joining jaw and the connecting block 1.11. In FIG. 12b, 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 FIG. 12a.

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 FIG. 12a into the retracted inactive position of FIG. 12b. 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 FIG. 12b to the advanced active position of FIG. 12a.

FIG. 13 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.

FIG. 14 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.

FIG. 15 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 jaw 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.

FIGS. 16a and 16b show the cutter 1.4′ with the blade 1.41′ in the advanced active position (FIG. 16a) and in the retracted inactive position (FIG. 16b). In FIG. 16a, 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 jaw nor with the cutter 1.4′. In FIG. 16b, 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′.

FIGS. 16c and 16d 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 FIGS. 16c and 16d) into the advanced joining position. In FIG. 16c, 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 jaw may therefore execute a joining operation without the strap being sheared by the blade 1.41′.

In FIG. 16d, 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.

STRAPPING DEVICE

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CPC

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