EP0847923B1 - Apparatus for strapping articles - Google Patents

Description

The invention relates to a device for strapping of packages according to the preamble of the claim 1.

Strapping devices of this type do this Strapping agent tight around a package and weld overlapping in the strapping device Strapping ends together, the loop formed from the stock of strapping material is separated. The strapping goes through during a working cycle of strapping guides, the strapping channel and strapping clamps in the area of the strapping device.

At the beginning of a work cycle, the strapping tool shot into the strapping channel, until the free leading end of the strap clamped in the area of the locking unit can be and the strapping guide located in the strapping area. To make the strapping fastener too can by overlapping strapping sections be connected to each other, it is required this strapping, mostly the function of a separator for the overlapping Strapping ends comes from the strapping level to control.

Now the strapping around the package tightened and the strapping fastener manufactured. This can be done by means of friction welding or else by means of resistance heating, which is part of the present invention is irrelevant. Important is, that the overlapping strapping ends until the strapping is finished and until the package is removed this from a headstock (sometimes in technical jargon also called "anvil" or "closure plate") against which the softened ends of the strapping are pressed to form a seal. On the side pointing away from the package, the Head plate itself as part of the locking unit be trained or hold parts of it. There the head plate, however, between the package and the Strapping closure area is arranged it is necessary to temporarily remove the headstock from the To control the strapping level, i.e. to move it, to release the welded strapping.

From this inevitable sequence of functions follows the disadvantage that occurs again and again in practice, that when the machine is triggered for a strapping cycle, where there is no strapping-capable package is strapped to the headstock. It forms such a strapping 'blind loop' that can cause significant malfunctions.

There have been both attempts to form a blind loop to prevent as well as suggestions that have arisen Blind loops from the work area of the Conveyor strapping device.

To avoid strapping blind loops you have a so-called on the strapping device Package detection provided. This includes one Sensor that detects whether a package is in the passage of the strapping guide channel is introduced or not. In the absence of a package the working cycle of the machine cannot be triggered. The packet detection works with automatic Operation quite reliable. With manual operation leaves there is a problem, especially with a fast package sequence, however, do not prevent rapidly operating operators a package is already out of the strapping channel pull out even before it straps correctly has been. The loop in progress then pulls around the locking unit. The result conditioned machine failure leads to an adverse Business interruption, the consequences of which are time-consuming, manual are to be fixed.

Around strapping blind loops to eliminate it has been suggested, at least a strapping clamp in a special way and Way to arrange so that they eject when starting exerts forces against the loop. The effect such a loop ejection is only with relatively low strapping tension at all basically possible and works in but not the rest even if, which is very rapid cycle can easily happen already a new package is available on the top plate.

The present invention is concerned with Problem with strapping parts strapping blind loops produced reliably remove from the working area of the machine to be able to. The facility that makes this possible should work automatically, and then also efficiently if there is any before the strapping blind loop is removed already a new package located in the strapping area.

The invention solves this problem with the features of claim 1 and is accordingly characterized in that in the strapping direction immediately in front of and behind the headstock Contact surfaces arranged for a strapping edge and that between them the entire strapping device, including Head plate and strapping clips, with reference to the strapping plane the strapping level is controllable.

In contrast to the prior art now all functional parts in the strapping plane from a strapping blind loop could be bordered from the strapping level led out. The strapping blind loop of the passive wipers Contact surfaces in front of and behind the head plate retained, so that when the shutter assembly functional parts be moved away from the strapping plane and thus from the area of the strapping device can fall out.

The control of the locking unit functional parts from the strapping level is preferred automatically after the completion of each strapping process, so inevitably, like So far only the head plate to release the finished one Strapping was temporarily adjusted.

However, compared to the prior art essential difference now in that not only the head plate, but all the functional parts of the Locking unit subject to the actuation movement. The head plate itself can therefore, e.g. with a load-bearing component of the closure assembly, in one piece trained or firmly attached to it.

According to a preferred further embodiment the invention provides that the strapping device including headstock and strapping clips around one Strapping plane extending parallel, at a distance pivoting axis extending from the locking unit is arranged. The strapping device can around the same axis as that Strapping means, but in opposite directions Direction, swiveling out of the strapping plane be arranged.

The swivel axis can be defined by a control shaft be the control cams for actuating the strapping clamps, the strapping guide and other organs of the closure unit. In this respect, a very compact assembly is achieved whose central control element from the control shaft and the associated control cam provided becomes.

The chute into which the strapping blind loop after stripping by modulation the functional parts of the locking unit fall into it, can at least one from the machine area leading sliding surface to be assigned so that the strapping blind loops in a simple manner outside the machine to the ground or in can fall into a collection container.

Fig. 1

eine Umreifungsmaschine in schematischer Ansicht,

Fig. 2

eine schematische Darstellung des Umreifungsmittel-Verschlußaggregats in einer ersten Stellung nach dem Straffen des Umreifungsmittels zur Bildung einer Blindschlaufe,

Fig. 3

eine der Fig. 2 entsprechende Darstellung des Verschlußaggregats unmittelbar vor der Ausbildung des Umreifungsmittelverschlusses an einer Blindschlaufe,

Fig. 4

eine schematische teilgeschnittene und bis zur Steuerwelle nach unten verlängerte Seitenansicht des etwa in der Stellung nach Fig. 2 befindlichen Umreifungsmittel-Verschlußaggregats, und

Fig. 5

eine der Fig. 4 entsprechende Darstellung, bezogen auf die Situation der Fig. 3.

Otherwise, the invention is best understood from its description below with reference to an embodiment shown in the drawings. show it:

Fig. 1

a strapping machine in a schematic view,

Fig. 2

2 shows a schematic illustration of the strapping device in a first position after tightening the strapping material to form a blind loop,

Fig. 3

2 shows the closure assembly corresponding to FIG. 2 immediately before the strapping closure is formed on a blind loop,

Fig. 4

is a schematic partially sectioned and extended down to the control shaft side view of the strapping device in the position shown in FIG. 2, and

Fig. 5

4 shows a representation corresponding to FIG. 4, based on the situation in FIG. 3.

On the machine frame 11 one in its entirety with 10 designated strapping machine an essentially closed strapping guide channel 12, through and around a with package 13 indicated by dash-dotted lines around a strapping means 14, in particular a thermoplastic plastic strap, a strapping device 15 is supplied. Whose The task is to overlap ends of the strapping means 14 surrounding the package to connect with each other, in particular through Heat to weld together. For this are in particular resistance heating or friction welding processes in use.

The strap 14 - e.g. also a Steel belt could be - will be outside the machine frame 11 on a rotatably mounted strapping roll (Drum) 55 in stock. First goes through the strapping means 14 on the machine input side a pair of rollers 16, which two on opposite one another Strapping surfaces frictionally has attacking roles that are tense towards each other and so with pressure against the strapping are held. The motor drive of this pair of rollers 16 promotes the strapping 14 in one Strapping agent store 17 of such a length of tensioning means 14 stored tension-free, such as he at least for the following strapping and for the Distance of the strapping material to the sealing unit 15 is required.

In the strapping feed direction onto the strapping stock 17 following is a second pair of rollers 18 arranged. Also the two roles of this Pair of rollers 18 drive the strapping 14 frictionally on. This pair of rollers is driven reversibly, because on the one hand it serves to fire the Strapping means 14 in the strap guide channel 12 and, with the opposite drive direction, on the other hand the withdrawal of the strapping means 14 and its tightening around the package 13. In the latter In sense, the pair of roles is a so-called "low Tension tensioning device ".

In the strapping feed direction, the bullet and retraction roller pair 18 still a "high Tension tensioning device "by means of tension drum 19 subordinate to the subject of another patent application and is of no further importance here. On this tension drum 19 still follow a special strapping clamp 20 and a guide channel 21, the the strapping means 14 to the strapping device 15 feeds.

Fig. 2 illustrates details of the strapping fastener assembly 15. Correspondingly this representation was the strapping means 14 of the shot roller pair 18 by the tension drum 19 and through the strap guide 21 fed to the strapping device 15, until the leading strap end 14 ' ran against a so-called bullet switch 23.

On its way there has free leading Strap end 14 'has a separator slot 24 in pass through a first strap clamp 25 and then one for guiding the strapping Separator 26 within a so-called "Weld clamp" 27. The two separator slots serve the strapping sections in their common overlap area (initially) from each other keep away. Then would - accordingly Fig. 1, but different from Fig. 2 - the strapping 14 the strap guide channel 12 have gone through and returned to the sealing unit his.

The actuation of the entry switch 23 by the leading, free strapping end 14 'signals the machine control the machine starting position and practically performs a 'reset'. This starting position is characterized by that within the strapping guide 12th (Fig. 1) already a strapping section of the Strapping means 15 is kept ready.

At the press of a button then initiated machine command the strapping process now sets itself after a package 13 is placed in the channel 12 is. The pair of rollers 18 receives the command to reserving drive and pulls the strapping 14 back, which corresponds to that of the pair of rollers 18 friction forces exerted around the package 13 begins to tighten. If the package 13 in a higher strapping tension as the "Low Tension" pair of rollers 18 the Strapping means 14 can exercise the "High Tension" tensioning drum 19 in the strapping tensioning process and tightens the strapping by turning with strong tension.

Fig. 2 shows the state that is in this situation if, on level E of the machine table, so the package support, accidentally no package 13 is present. You can see that that Strapping means 14 then in tight loop formation the so-called head plate 22, which is the first strap clamp 25 and the separator 26 as well the strapping sections present in this area from the package lying on level E. should keep away, wraps around. Further wraps around the strap loop the counterholder 42 for a second strap clamp 41.

Subsequent to the machine cycle runs the second strap clamp 41 against the counter-holder 42 and clamps a strapping section here. The welding clamp continues to drive 27 with one attached to its face Cutting knife 28 against the head plate 22, the one forming the strap loop Strapping section from the supplied strapping section separates and the overlapping strapping sections 14 'and 14 "together against the Bottom of the head plate 22 are pressed. This everything happens after the strapping 14 previously leading separator 26 from the strapping plane 31, namely from the plane of FIG. 2 to the viewer out, was swung out like it out Fig. 4 can be seen. The overlapping one another Strapping sections 14 'and 14 "are now on not described in detail and also not shown Way firmly connected, in particular plasticized by heating and together merged.

The strapping means 14 runs correctly Package lying around on level E has about 3 in dash-dotted lines 14 ‴. Around the strapped package 13 from level E The top plate can usually be removed 22 and the counter-holder 42 from the strapping plane steered out, e.g. perpendicular to the strapping plane postponed.

Is in the formation of the strapping fastener however, a package to be strapped does not is present, a so-called 'blind loop' is formed 32, as in Figs. 2 and 3 shown. A strapping course thus arises one as he pulled through Line is shown. As already stated, wraps around the strapping blind loop 32 the top plate 22 and the counterholder 42. Also located the first strap clamp is also in the strapping plane 25, the welding clamp 27 with the knife 28 and the second strap clamp 41.

In order to ensure that one manufactured incorrectly Strapping blind loop 32 automatically and safely from the locking unit area can be removed without causing malfunction can come, are all functional parts of the Strapping device 15, namely the Head plate 22 and the counter holder 42 on the inside the blind loop 32 and the first strap clamp 25, the welding clamp 27 with Knife 28 and the second strap clamp 41 outside of the blind loop 32 all and preferably controllable together from the strapping level 31.

In the exemplary embodiment, this is done by Swiveling around the longitudinal axis 43 of a common one Control shaft 44. In the area of the strapping level 31 only one contact surface 29 is retained and 30 against which the strap 14 with its indicative edge edge or where it is can support.

Fig. 5 shows how all functional parts of the Strapping device from the strapping plane 31 are pivoted out such that the Strapping blind loop 32 in free fall the unit area can fall out. To ensure, that they complete the area of the machine leaves, by swiveling the unit away 15 emerging chute 33 still sliding surfaces 34 provided. These are with the swivel Unit 15 firmly connected or in a suitable Fixed in place on the machine frame.

So that a strapping blind loop is thrown off 32 in any case and automatically can, this happens in the embodiment by means of Swiveling realized control of the functional parts of the strapping fastener assembly 15 once during each strapping cycle, and immediately after completion of the strapping closure. Then the head plate also comes - which are now not movable on their own needs to be stored - between strapping closure and package 13 free so that this is removed can be.

It is remarkable in the context of the invention that that a strapping blind loop 32 itself then safely removed from the aggregate area can be if a package is in the strapping plane is or the closure plate with high tension is strapped. For this success the Invention, it is essential that all below of the blind loop 32 located aggregate parts temporarily moved out of the strapping plane become, whereby the chute automatically for the automatic release of the blind loop.

Claims (5)

1. Device for strapping packages having a means for girdling (14), in particular a thermoplastic tape, which is introduced from a girdling means supply (55) into a girdling means channel (12) surrounding the package (13) and fed through this to a girdling means closure unit (15), wherein the circular girdling means loop formed in this way defines the girdling means plane in which on the closure unit side a girdling means guide (21) capable of being steered out of the girdling plane, equipped if necessary with a separator for the girdling means sections overlapping one another in the closure region, is provided ahead of formation of the girdling means closure and wherein in the girdling plane the girdling means closure unit (15) is covered in the direction of the package by a cover plate (22) which can be steered out of the girdling plane to release the girdling means following formation of the girdling means closure and wherein controllable girdling means clamps (25, 41) are allocated to the girdling means closure unit, characterised in that in the girdling means guide direction directly in front of and behind the cover plate (22) contact surfaces (29, 30) for a girdling means edge are arranged and that between the latter the entire girdling means closure unit (15) including the cover plate (22) and girdling means clamps (25, 27, 41, 42) can be steered out of the girdling plane (31) when the contact surfaces (29, 30) are fixed with respect to the girdling plane.
2. Device according to Claim 1, characterised in that the girdling means closure unit (15) including the cover plate (22) and girdling means clamps (25, 27, 41, 42) is arranged so that it can be swung out about an axis (43) extending parallel to the girdling means plane (31) and running at a distance from the closure unit (15).
3. Device according to Claim 2, characterised in that the girdling means closure unit including the cover plate and girdling means clamps (25, 27, 41, 42) is arranged so that it can be swung out of the girdling means plane (31) about the same axis (43) as the girdling means guide (26) but in the opposite direction.
4. Device according to Claim 2 or 3, characterised in that the swivel axis (43) is defined by a control shaft (44) which carries peripheral cams (45) for operating the girdling means clamps (25; 27, 28; 41, 42), the girdling means guide (26) and if necessary elements forming the closure.
5. Device according to Claim 1, characterised in that as a result of steering the girdling means closure unit (15) out of the girdling plane a drop shaft (33) is produced and that at least one slide surface (34) leading out of the machine region is allocated to the drop shaft (33).

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