EP0819604B1 - Strap guiding frame for a strapping machine - Google Patents

Description

The invention relates to a strap guide frame for a strapping machine with the features specified in the preamble of claim 1.

Such tape guide frames are an integral part of one Strapping machine, which ensures that the strapping as loose Loop around the packaged goods positioned in the frame opening becomes. Through the circumferential belt channel on the belt guide frame the belt usually transported by a shooting device clean guided.

To tighten the belt around the packaged goods, the belt must now be removed from the Band channel can get out. For this purpose are from the prior art on the one hand, flaps controlled by special drives on the inside the band channel known, which before pulling the band from the Strapping plane are swung out and thus the strap channel open inside.

The invention, on the other hand, is based on a "passive" - ie not motor controlled - coverage of the band channel as the closest state of the Technology off. In addition to one that limits the outside of the band channel the guide rail attached to the frame base there is the band channel with a moving. Cover provided from a variety of circumferential of the volume lined up, overlapping each other Slats is composed. The slats are so resilient the frame base stored so that when you tighten the strapping be acted upon by this and thereby become practically automatic Lift the opening of the band channel from the frame base.

The spring bearing of these slats is relatively narrow and in extreme cases coil springs formed on block which are perpendicular from the frame base are mounted protruding. The base of the respective coil spring sits e.g. on a pin attached to the frame base. The head of the coil spring is screwed to the lamella. Per slat at least two such coil springs must be provided.

As an example of such a spring mounting Document US-A-5,414,980.

The disadvantage of this known spring mounting of the slats is the high one design effort for spring and lamella assembly. Further must the springs and lamellae are adjusted properly so that a perfect Opening and closing of the slats is guaranteed.

Based on the problems described, the object of the invention to simplify the design of the spring support of the slats, without impairing their perfect opening and closing behavior.

This object is achieved by the specified in the characterizing part of claim 1 Features solved. Accordingly, the spring support of the slats each used a rubber-elastic spring plate, which on a assigned, seated on the frame base and mounted on which the slat is suspended from.

The spring plate provided according to the invention as such represents a far greater easier to manufacture and assemble component than that in the prior art Technology used coil springs. Furthermore, each spring plate for the present application a favorable spring behavior, because there is a relatively high degree of rigidity in the plate plane, while transverse a very elastic deflection behavior is achieved at the plate level. This means that the lifting of the slats and the associated deflection movement the spring plate in the transverse direction relative to its main plane easily proceed while the slats are overlapping in their mutually Assembly positions are kept clean.

Advantageous embodiments of the invention are in the subclaims specified. In this context it should be noted that under the term "slats" not only those from the prior art known stamped and bent parts made of sheet metal are to be understood. Much more According to preferred developments, slats are also possible particularly easy to manufacture as injection molded parts and thereby from the outset provided with appropriate mounting options for the spring plates can be. This sets the manufacturing effort for the tape guide frame further down.

Fig. 1

eine Seitenansicht eines Bandführungsrahmens für eine Umreifungsmaschine in einer ersten Ausführungsform,

Fig. 2

eine perspektivische, ausschnittsweise Detaildarstellung des Bandführungsrahmens aus Pfeilrichtung II nach Fig. 1 in geschlossenem Zustand des Bandkanals,

Fig. 3

eine Ansicht analog Fig. 2 in teilweise geöffnetem Zustand des Bandkanals,

Fig. 4

einen ausschnittsweisen Horizontalschnitt durch den Bandführungsrahmen entlang der Schnittlinie IV-IV nach Fig. 1,

Fig. 5

eine Detaildraufsicht auf den Bandführungsrahmen aus Pfeilrichtung V nach Fig. 4,

Fig. 6

einen Horizontalschnitt analog Fig. 4 durch einen Bandführungsrahmen in einer zweiten Ausführungsform,

Fig. 7 bis 9

eine Seiten-, Vorder- und Draufsicht auf eine als Spritzgußteil ausgebildete Lamelle in einer weiteren Ausführungsform,

Fig. 10

einen schematischen Schnitt analog Fig. 4 durch eine Einheit aus Träger, Federplatte und Lamelle entlang der Schnittlinie X-X nach Fig. 12,

Fig. 11 und 12

Ansichten der Einheit gemäß Fig. 10 aus Pfeilrichtung XI und XII, sowie

Fig. 13

einen schematischen Schnitt durch eine Einheit analog Fig. 10 in einer weiteren Ausführungsform.

Further features, details and advantages of the invention also result from the following description in which exemplary embodiments of the subject matter of the invention are explained in more detail with reference to the accompanying drawings. Show it:

Fig. 1

a side view of a strap guide frame for a strapping machine in a first embodiment,

Fig. 2

2 shows a perspective, detailed illustration of the band guide frame from arrow direction II according to FIG. 1 in the closed state of the band channel,

Fig. 3

2 in a partially open state of the band channel,

Fig. 4

2 shows a partial horizontal section through the tape guide frame along the section line IV-IV according to FIG. 1,

Fig. 5

3 shows a detailed top view of the tape guide frame from arrow direction V according to FIG. 4,

Fig. 6

4 through a tape guide frame in a second embodiment,

7 to 9

a side, front and top view of a lamella formed as an injection molded part in a further embodiment,

Fig. 10

4 shows a schematic section analogous to FIG. 4 through a unit consisting of carrier, spring plate and lamella along the section line XX according to FIG. 12,

11 and 12

10 from the direction of the arrow XI and XII, and

Fig. 13

a schematic section through a unit analogous to FIG. 10 in a further embodiment.

Fig. 1 shows the tape guide frame 1 as part of a not shown Strapping machine, which is usually on the work table of the Machine is built. The frame 1 forms an opening 2 in which the Packaged goods P to be strapped are inserted using a transport device and transported out of it again after the strapping process becomes.

The tape guide frame 1 has one of corresponding plate elements 3, 4, 5 composite frame base 6, which in Fig. 1 only is shown schematically. Furthermore, a circumferential is on the tape guide frame 1 Strap channel 7 for guiding a strapping strap 8 (see 2 to 5) are provided around a packaged product P. The band channel 7 leads from a welding head 9 shown schematically in Fig. 1 below the Opening 2 around the legs of the tape guide frame 1 around back to the welding head 9.

As indicated in dashed lines in Fig. 1, the band channel 7 is on the outside limited by a guide rail 10 attached to the frame base 6, on the respective plate elements 3, 4 and 5 by appropriate Bracket 11 (Fig. 4) is attached so that a circumferential Guide surface 12 for the strapping 8 is formed. At this guide surface 12 runs along the shooting strapping 8.

The band channel 7 is moved inwards towards the packaged product P by a movable one Cover 13 bounded by a variety of circumferential U lined-up slats 14 is composed.

As is clear from FIGS. 2 and 4, each lamella 14 is an angled plate with a bearing leg running essentially parallel to the frame base 6 15 and a wall leg 16 formed with the bearing leg 15 an obtuse angle W slightly exceeding 90 ° forms. The wall leg 16 has a bevel at its free end 17 with which it rests on the frame base 6.

As is clear from FIGS. 1 to 3, each lamella 14 overlaps with the subsequent lamella 14, the lamella following in the direction of rotation U. 14 is placed outside on the preceding lamella 14. As a result, there is no shooting-in of the strapping in the band channel 7 8 obstructing edges against the shooting direction of the Band. Otherwise, the band channel 7 is particularly clear, as shown in FIG. 4 is approximately trapezoidal in cross-section, with the outside - As discussed - by the guide surface 12 of the guide rail 10, after inside through the wall leg 16 of the lamella 14 and in the area of it both narrow sides through the corresponding areas of the frame base 6 or the bearing leg 15 is limited to that shown in FIG. 4 closed state of the band channel 7 rests on the guide rail 10.

Each slat 14 is by means of a spring plate 18 via a carrier 19th so resiliently mounted on the frame base 6 that they pull when tightening of the strapping around the packaged goods P for the automatic opening of the Band channel 7 can be lifted from the frame base 6. Each spring plate 18 is elongated rectangular in shape and made of a rubber-elastic material, such as. Polyurethane rubber formed. The carrier 19 is in each case formed as a cross-sectionally U-shaped profile part, which with its a leg 20 on the frame base 6 by corresponding rivets 21 is attached. On the inside 22 of the frame base 6 pointing second leg 23 is the upper base 24 of the spring plate 18 and is fastened there with two corresponding rivets 25 The spring plate 18 stands with its width beyond the leg 23 and carries on lower base 26, the respective lamella 14, which has two more Rivets 27 are attached to the spring plate 18. As is clear from Fig. 5 is, the length of the carrier 19 and the spring plate 18 is approximately that Half of the length of the lamella 14. The support 19 and the lamella 14 are also parallel to one another on the longitudinal side regions facing away from one another 28, 29 of the spring plate 18 attached.

With reference to Fig. 1 it should be noted that due to the simple attachment and storage of the slats 14 using the spring plates 18 and carrier 19 it readily from the manufacturing Effort is justifiable over the entire circumferential length of the belt guide frame 1 with slats, spring plates and carrier plates of a uniform Overall length of z. B. 10 cm to work. The use of longer Slats 14 'in straight areas of the band channel 7 is in contrast basically known from the prior art and leads to a Increase the number of different ones required for machine construction Items.

2 and 3 is the automatic, passive opening mechanism to explain:

After shooting the strapping 8 into the band channel 7, such as this is shown in Fig. 2, the leading end of the strapping 8 held in the welding head 9 and the tape pulled back. Thereby pulls the loop formed and acts on the Slats 14, due to the spring-elastic mounting by the spring plates 18 dodge upwards and the tape guide channel 7 inwards release (Fig. 3). After the strapping 8 under the folds 17 of the slats 14 has slipped through, leads through the Deflection of the spring plates 18 acting restoring force R the fins 14 back to the starting position shown in FIG. 4. In that with it closed band channel 7, the strapping 8 can then again for the next strapping process.

6 shows a further exemplary embodiment of an inventive one Tape guide frame 1 shown. Here, the carrier 19 'is a plastic injection molded part, which in turn is U-shaped in cross section and with one leg 20 'is attached to the frame base 6. The second Leg 23 'does not run parallel to the lower leg 20', but from the base 30 starting obliquely upwards and is through an intermediate web 31 stably supported. At the free end of the upper leg 23 'is in a Groove 32 in turn inserted the spring plate 18 ', the carrier 19' itself extends at least over the length of this spring plate 18 '. So that's the leg-side long side region 28 'of the spring plate 18' over its entire length Length of the groove 32 includes.

On the opposite longitudinal side area 29 'of the spring plate 18' is the Lamella 14 '' fastened by a clip connection 33. In contrast to the Slats in the embodiment according to FIGS. 1 to 5 is the slat 14 "according to FIG. 6 not an angled sheet, but an easy to manufacture one Plastic injection molding. This injection molded part is analogous to the fins 14 as an angle piece with a bearing leg 15 'and a wall leg 16' educated. In this respect there is no difference in the basic structure to the Slats 14 of the first embodiment. This is manufacturing technology Injection molded part, however, much easier and cheaper.

In Fig. 6, the guide rail 10 'can also be seen, which as a continuous Metal band is formed and held by the carriers 19 '. Point to this the latter molded on boom 34, between which and the frame base 6 the practically continuous guide rails 10 'is clamped. The slats 14 '' are again supported on the upper edge of the guide rail 10 '. With the help, for example, of approximately 5 cm long supports 19 'with corresponding ones Slats 14 ″ can be a belt channel in a modular manner on the frame base 6 7 can be realized by a plurality of such supports 19 'with lamellae 14 '' strung together with the course shown in FIG. 1 and then the continuous guide rail 10 'between the arms 34 and the frame base 6 are introduced. In the curve areas of the Band channel 7, the beams 19 'describe a polygonal curve, the guide rail 10 'evenly curved the course of the bend adapts and only via a line contact at the respective base 30 the support 19 'supports, as shown in Fig. 6.

Otherwise, the carrier 19 'is simple in terms of production technology a locking lug 35 in a corresponding opening 36 of the frame base 6 established.

It should be noted that in FIG. 6 the carrier 19 ', the spring plate 18' and the lamella 14 "are shown as separate components. However, it is also conceivable, the spring plate 18 'as a pre-molded component in an injection mold to insert and at the same time to spray the carrier 19 'and the lamella 14 "onto it. Can do just as well in a two-component spraying process on the one hand spring plate 18 'made of a rubber-elastic material and on the other hand Carrier 19 'and lamella 14 "made of a dimensionally stable material in be sprayed together in one operation.

7 to 9 is another embodiment for a plastic injection molded part executed lamella 14 '' 'shown. This is essentially again as an angle part with a bearing leg 15 '' and a Wall leg 16 '' designed. On the bearing leg 15 '' are in the area of the two longitudinal ends of flanges 37 with opposite one another Axle stub 38 projecting in one piece, the part a hinge joint to be explained in more detail for additional articulation of the slats 14 '' 'on the carriers. The fins 14 "'are further in the area of their inlet-side overlap area 39, in the the outlet-side end of the previous slat scaly under the subsequent lamella engages both in the area of the bearing leg 15 " as well as the wall leg 16 "with an offset 40 to the outside. This allows the successive slats 14 '' 'to be clean overlap and on the inside as smooth a band channel as possible 7 form.

10 to 12 is another embodiment of the invention using the lamellae detailed in FIGS. 7 to 9 14 '' 'shown. As is clear from these figures, the carrier 19 "is a essentially box-shaped plastic injection molded part, which in turn is fixed via latches 35 in openings 36 of the frame base 6. The Carrier 19 "has an upstanding holding body in its interior 41 42, at its upper end an inclined groove 32 'for receiving of the corresponding longitudinal side region 28 'of the spring plate 18 " is. Their other long side region 29 'is in turn more suitable Way in the bearing leg 15 "of the lamella 14" 'set.

As is clear from FIGS. 11 and 12, the narrow side walls 43 have of the carrier 19 "at the upper end recesses 44 into which the stub axle 38 engage the slats 14 "'to form a hinge joint. The slats 14 '' 'are thus pivotable about the axis S am Carrier 19 "is articulated, the pivot axis - as can be seen in FIG. 10 S lies in the area of the plane of the spring plate 18 ″ Figure also recognizable bend of the spring plate 18 '' is the lamella 14 '' 'biased in the closed position shown.

As is clear from FIGS. 11 and 12, the length of the carrier corresponds to 19 " essentially that of the lamella 14 '' '. It also forms the band channel 7 inner wall 45 located at the same time the limitation for this band channel. Carriers 19 "which are placed seamlessly next to one another thus form with their inner walls 45 as the guide leg together the guide rail 10 of the tape guide frame. In this way also a curved band channel course To be able to implement, the carriers 19 '' have on their inner walls 45 nose projections 46 on one side and on the other Page shape-matching shots 47 on. To realize a band channel course So carriers 19 '' are strung together, the nose-like Projection 46 of a carrier 19 ″ into the corresponding receptacle 47 of the previous wearer. Since nose-like projection 46 and receptacle 47 form a kind of elongated socket joint, two can be on top of each other following carrier 19 "in a different from the stretch Angle can be arranged. Because of a slightly recurrent course the inner wall 45 in the region of the receptacle 47 ensures that the leading end of the strapping 8 no obstacle in the way stands.

It should also be noted that the additional pivotable linkage of the slats 14 '' 'on the supports 19 "an even more defined opening and closing behavior when acting on it the tape channel 7 pulling tape is made possible. This means that the overlap areas, the dimensioning of which is always the worst Case must emerge when the strapping 8 emerges, tighter can be chosen. This has the advantage that per belt frame length fewer supports / spring plates / slat units used and fewer Forces for opening the band channel 7 are applied by the band have to.

Finally, in Fig. 13 is a schematic side view of another one Embodiment of the carrier / spring plates / slat unit shown. It is again a lamella 14 ″ ′ designed as a plastic injection molded part is used, in which the hinge joint indicated schematically with 48 its pivot axis S not in the plane of the spring plate 18 '' ', but with a clear distance below it. The latter is with its slat-sided Longitudinal region 29 "in turn in a groove 32" in the lamella 14 '' 'set. The other long side region 28 "is only supported on a corresponding bevel 49 of the support 19 "'. By bending the Spring plate 18 '' 'in turn causes a preload on the lamella 14' '. Furthermore, the distance of the pivot axis S from the Level of the spring plate 18 '' 'when bending the lamella 14' '' and the further deflection of the spring plate 18 '' 'causes a sliding effect, which holds the spring plate 18 '' 'within the groove 32 ". Therefore the spring plate needs 18 '' 'can only be fixed on one side, which is assembly-related has a favorable effect.

Claims (18)

1. A strap guiding frame for a looping machine, comprising a frame base (6) and an encircling strap channel (7) for a looping strap (8) to be guided around a product stack (P), the strap channel (7) being formed on the frame base (6) by a guide bar (10, 10'), which is located on the frame base (6) and defines the strap channel (7) externally, and by a movable cover (13), which defines the strap channel (7) internally toward the product stack (P) and which is composed of a plurality of overlapping lamellae (14, 14', 14", 14"') lined up in the direction of circulation (U) of the looping strap (8), the lamellae (14, 14', 14", 14"') being spring-mounted on the frame base (6) in such a way that when the looping strap (8) is tautened around the product stack (P), they can be lifted off the frame base (6) for the automatic opening of strap channel (7), characterized in that the spring-mounting of the lamellae (14, 14', 14", 14"') is formed by a rubber-elastic spring plate (18, 18', 18", 18"'), which is supported on an associated support (19, 19', 19", 19") located on the frame base (6), and on which the lamella (14, 14', 14", 14"') is suspended.
2. A strap guiding frame according to claim 1, characterized in that the respective spring plate (18, 18', 18", 18"') is of elongated rectangular shape, the support (19, 19', 19", 19"') and the lamella (14, 14', 14", 14"') being fixed parallel to each other on the lengthwise portions (28, 28', 28", 29, 29', 29"), turned away from each other, of the spring plate (18, 18', 18", 18"').
3. A strap guiding frame according to claim 1 or 2, characterized in that the support (19, 19') is a section of U-shaped cross-section, one leg (20, 20') of which is mounted on the frame base (6) and on the second leg (23, 23') of which the respective spring plate (18, 18') is disposed.
4. A strap guiding frame according to claim 3, characterized in that the spring plate (18) is disposed on the inside (22), turned toward the frame base (6), of the second leg (23).
5. A strap guiding frame according to claim 3 or 4, characterized in that the lamella (14) and the second leg (23) of the support (19) are mounted on the bases (24, 26), turned away from each other, of the spring plate (18).
6. A spring plate according to one of claims 1 to 5, characterized in that each lamella (14, 14', 14", 14"') is an angled part, one leg of which is fixed as a bearing leg (15, 15', 15") to the spring plate (18, 18', 18", 18"') and, in the closed condition, rests on the guide bar (10, 10'), forming a narrow side wall of the strap channel (7), and the second leg of which, as a wall leg (16, 16', 16"), partially forms the inner side wall of the strap channel (7).
7. A strap guiding frame according to claim 6, characterized in that the edge of the wall leg (16) that rests on the frame base (6) has an edged portion (17).
8. A strap guiding frame according to one of claims 1 to 7, characterized in that the lamellae (14, 14'), spring plates (18) and supports (19) are fixed to each other by rivetings (25, 27).
9. A strap guiding frame according to one of claims 1 to 8, characterized in that at least on three sides of the strap guiding frame (1), the strap channel (7) is formed by lamellae (14, 14', 14", 14"'), spring plates (18, 18', 18", 18"') and supports (19, 19', 19", 19"') of a uniform overall length.
10. A strap guiding frame according to one of claims 1 to 9, characterized in that the spring plates (18, 18',. 18", 18"') consist of a rubber-like plastic material, in particular of polyurethane rubber.
11. A strap guiding frame according to one of claims 1 to 10, characterized in that the supports (19', 19", 19"') are plastic injection-molded parts.
12. A strap guiding frame according to one of claims 1 to 5 or 7 to 11, characterized in that the lamellae (14", 14"') are plastic injection-molded parts.
13. A strap guiding frame according to claim 12, characterized in that the lamellae (14", 14"') have a misalignment (40) in the portion (39) on the inlet side where they lap the neighboring lamella (14", 14"').
14. A strap guiding frame according to one of claims 1 to 13, characterized in that the lamellae (14", 14"') are additionally articulated to the supports (19", 19"') by way of a hinge (38, 44, 48).
15. A strap guiding frame according to one of claims 1 to 14, characterized in that the supports (19') are formed as holders for the guide bar (10').
16. A strap guiding frame according to one of claims 1 to 14, characterized in that the supports (19', 19") are elongated components and have guide legs (45) which, by the supports (19", 19"') being lined up without gap, combine to form the guide bar of the strap guiding frame (1).
17. A strap guiding frame according to one of claims 1 to 7 or 9 to 16, characterized in that the lengthwise portions (28', 28", 29', 29") of the spring plates (18', 18", 18"') are fixed in grooves (32', 32") on the lamellae (14", 14"') and/or the supports (19', 19", 19"').
18. A strap guiding frame according to claim 11 and 12, characterized in that a support (19'), a lamella (14") and a spring plate (18') are formed in one piece as an injection-molded part.

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