EP1283797B1 - Device for tightening strapping bands - Google Patents

Description

The invention relates to a device for tensioning strapping, especially made of plastic, with an abutment and with a driven by a tension motor via a gear, with a backstop provided tensioning wheel, which with the Abutment forms a tension channel for the strap ends to be tensioned and with the tension motor and the gear in one gear block is arranged as a whole in the base frame of the device is pivotally mounted about a first fixed axis and from holding means mounted on a tensioning wheel pivot with friction held in its ineffective position, lifted from the end of the tape is and under the action of a pressure element is pivoted against the abutment when the tensioning wheel in Clamping direction starts and the holding means its effective position loses.

A device of this type is known (EP 0 664 256 B1), where the lower band end between the base plate of the device and an intermediate wedge is clamped while the upper End of the belt between the tensioning wheel and the intermediate wedge must, before the tensioning wheel when starting from a spring on the Abutment is pressed and the upper end of the band over the intermediate wedge pulls and thus tense. After tensioning and welding, if necessary of the band ends, it is then necessary to use the tensioning wheel to ventilate a special hand lever provided for this purpose and against the effect of the strong tension spring in its off the belt to take off, ineffective position so that the device be pulled off the strapping on the side and back can.

Inserting the tape ends and venting the tensioning wheel is difficult, requires strength when depressing the hand lever and can usually not be done with one hand. Since the tape ends to be connected through different openings of the tape channel run, they can only be inserted one after the other it can easily happen that they face each other laterally in the device shift and not during subsequent welding lie exactly on top of each other and result in incorrect welding is.

With a similar device (handheld device CE 92 from Cyklop GmbH) not the tensioning wheel, but the abutment and intermediate wedge with one special hand lever pivoted back to between the profiled peripheral surface of the tensioning wheel and the intermediate wedge to release the jammed upper band end and open the band channel.

A tensioning device is also known (handheld device PN 6.1 Cyklop GmbH), which is used for tensioning strapping with steel straps serves, the strap ends after strapping with a seal be closed. Here, both ends of the band are. the sealing seal pulled, the lower end of the band around the sealing seal folded and thereby secured against pulling out, while the upper end of the belt is passed from a tensioning wheel over a Tensioning wedge is pulled by a spring against the tensioning wheel is pressed. If the strapping before closing the Seal should be loosened again to tighten the strapping correct or re-tension, you can run the tensioning wheel backwards to let. To remove the device from the cocked and closed strapping it is then also necessary here Swing the tensioning wedge back with a hand lever to the band channel open and pull the device out of the strapping to be able to.

The object of the invention is a device of the beginning explained type in such a way that this also plastic tapes with ends of tape lying directly one above the other In the initial position, the band channel is open on the side and can be excited, just by switching on of the tensioning motor tensioning wheel and abutment in their tensioning position arrive and tighten the strapping and after completion of the clamping and, if necessary, closing process itself detach from the strapping again, return to their starting position and open the tape channel again.

This object is achieved with the invention in that the Tensioning wheel from the tensioning motor in the tensioning direction and in the opposite direction is drivable and that the backstop with a freewheel Brake is, which locks the reverse rotation of the tensioning wheel when the tensioning motor stops, which however reverses the Tension wheel allowed when the tension motor runs backwards and that the tensioning wheel with its tensioning wheel pivot in an eccentric is rotatably supported with friction, which in turn is in a steering lever is rotatably guided, which is about a second, fixed axis is pivotally mounted on the base frame and that as a holding means a freewheel locked against the tensioning direction between Tensioning wheel journal and eccentric is arranged.

This configuration has the advantage that a special, of Hand operated mechanism is not required to Tensioning wheel and abutment from their engagement with the tape ends too solve, but that it is sufficient to move the tension motor to forward gear switch on to bring the tensioning wheel into working position and initiate the tensioning process and later the tensioning motor in reverse gear to switch to lift the tensioning wheel from the abutment and open the tension channel. The device can be used with just one Hand grasped and guided, the strapping leaves insert yourself lightly with the other hand and out of the Pull out the band channel and start the tensioning process and To open the band channel, only one button on the device has to be pressed become.

As already mentioned, the strap ends in the tensioning channel can be used directly lie on top of each other, with the lower end of the tape from the Surface of the abutment is held in place by friction the upper end of the band from the profiled Circumferential surface of the tensioning wheel on the surface of the lower one Pulled along the end of the belt and thereby around a package or the like. is excited. This has the advantage that the two lie one above the other Band ends simultaneously from the side with one hand can be inserted into the open clamping channel while the other hand holds the jig and by pressing a button initiates the tensioning process.

In order to swivel the tensioning wheel precisely and effectively To ensure tensioning of the tape, the first can be fixed Axis of the gear block and the second fixed axis of the steering lever be arranged on different sides of the abutment, expedient in such a way that the first fixed axis of the gear block in the clamping direction in front of the abutment and the second fixed Axle of the steering lever is arranged behind the abutment. This ensures that when the tensioning wheel is turned on against the abutment the clamping angle between the abutment surface and tensioner tangent automatically changed so that the on Band exerted clamping effect greater with increasing band tension is that but also the tensioning wheel when later lifting off the interconnected band ends in the opposite direction can run off and detaches itself from the tape. in this connection the tensioning wheel is guided by the eccentric and steering lever in such a way that it when the tensioning wheel rotates in the tensioning direction Is pivoted against the abutment and at one Lift the tensioning wheel in the opposite direction from the abutment becomes.

The bearing friction of the tensioning wheel journal in the eccentric should be expedient not be too big so that the tensioning wheel is sufficiently high Can exert tension on the strap end to be tensioned. It is therefore useful if the eccentric under the action of a is the first pressure element, which strives to the eccentric in To turn the tensioning direction of the tensioning wheel. This pressure element can a torsion spring or a spiral spring, which is the rotational movement the eccentric supports or carries out.

The second freewheel with brake is useful in the drive shaft train arranged of the gear for the tensioning wheel and locks the Reverse rotation of the drive shaft train when the tensioning wheel the desired Belt tension has generated and the tension motor stops. However, the brake allows the drive shaft train to reverse, when the tension motor runs backwards. hereby is achieved that the strapping without loading the tensioning motor is kept under tension until the tape ends, for example with a seal or by welding them together have been connected and cut off before then that Tensioning wheel runs backwards and thereby swings back into its starting position.

The brake on the second freewheel can be one with the freewheel hub connected brake disc, which is between by spring elements compressed solid friction elements runs.

To reliably tighten the tensioning wheel when starting in the tensioning direction Swiveling down to exciting band ends is a pressure element a torsion spring wound around the pivot axis of the gear block provided which counter the pivoting movement of the tensioning wheel supports the fixed abutment. In the ventilated, from Abutment raised position, the tensioning wheel is then countered the effect of the spring by the cogging torque of the tensioning motor and / or by the freewheel lock in the transmission and by the Freewheel lock held in the eccentric.

It is particularly useful if the eccentric on one around the Tensioning wheel trunnion arranged rotatable hinge side guide element which is under the action of the first pressure element, which the hinge side guide element so far in the tensioning direction turns that it covers the band channel laterally when that Tensioning wheel in its tensioned position pivoted down on the abutment located. This hinge side guide member is one Sector disc, one at its front edge in the clamping direction has an inward conductive bevel. If the band ends after after inserting it into the band channel laterally protrude from the outside, they will after swiveling the sector disk captured by the chamfer and pressed completely into the band channel. When tensioning, the ends of the strap can not be on the side slide out of the band channel.

Fig. 1 eine Vorrichtung nach der Erfindung bei abgenommenem Gehäuse in einer schematischen, perspektivischen Darstellung in der Ausgangsstellung mit eingelegtem Umreifungsband,

Fig. 2 den Gegenstand der Fig. 1 in einer Seitenansicht,

Fig. 3 eine der Fig. 2 entsprechenden Darstellung, bei der sich die Spannvorrichtung in ihrer Spannstellung befindet und

Fig. 4 den Gegenstand der Fig. 3 in einem Teilquerschnitt nach Linie IV-IV der Fig. 3.

Further features and advantages of the invention result from the following description and the drawings, in which a preferred embodiment of the invention is explained in more detail using an example. It shows:

1 shows a device according to the invention with the housing removed in a schematic, perspective view in the starting position with the strapping inserted,

2 shows the subject of FIG. 1 in a side view,

Fig. 3 is a representation corresponding to FIG. 2, in which the clamping device is in its clamping position and

4 in a partial cross section along line IV-IV of FIG. 3rd

The tensioning device 10 shown in the drawings serves for tensioning a plastic strapping 11, namely made of stretched polyester, which is a not shown Package is laid around and its lower end of the band 11a and whose upper band end 11b lies directly on top of each other the tensioning device 10 tensioned and then with a welding device 12 welded and cut from the tape supply. The welding device 12 is not the subject of the invention and is therefore not shown in detail here described.

The clamping device 10 has a base frame 13 with a Base plate 14, on which a perpendicular central wall 15 and a bearing block 16 attached or to the base plate 14 are cast from one piece. The two upright and cheeks 16a and 16b of the bearing block 16 carry one at their upper, free ends first, fixed axis 17, which is in the clamping direction 29 in front of the abutment is located and on which a gear block 18 is pivotable is stored. The gear block 18 is from a gear housing 19 surrounded on which a tension motor 20 is arranged, the can work in both directions and at least in switches off in a direction of rotation depending on the load.

The transmission 31 arranged in the interior of the transmission housing 19 is described in more detail below. It is on the in Fig. 1st right side of the tensioning device 10 connected to a tensioning wheel 21, this together with the gear block 18 and the one on top of it attached tension motor 20 pivotable about the first fixed axis 17 is and from the tension motor 20 via a toothed belt 22 and that Gear 31 can be driven in both directions of rotation. The tensioning wheel 21 has a profile on its peripheral surface 25 23 and acts with an abutment 24 in the base plate 14 together, which is embedded in the base plate 14 and also has a profile not shown here. The profiled peripheral surface 25 of the tensioning wheel 21 forms together with the abutment 24 a tape channel 26 for the tape ends 11a and 11b, the inoperative initial state of the device 10 open on the right side of the device in FIG. 1 is so that the tape ends 11a and 11b from the right side forth between tensioning wheel 21 and abutment 24 in the tensioning device 10 can be inserted. On the inside of the band channel 26 there is an inner hinge side guide 27 (FIG. 2 and 3), which the strap ends during tensioning on their in Fig. 1st left, inner margin leads, while the outer, right Side edges of band ends 11a and 11b in the device of FIG an outer hinge side guide member 28 which when tightening the strapping 11 covers the band channel 26 outside and will be described in more detail below.

As already mentioned above, the upper band end 11b in Clamping direction 29 from the tensioning wheel 21 on the surface of the lower one End of band 11a pulled and tensioned, while the lower Strip end 11a from surface profiling or corrugation the abutment 24 is held. The direction of tension 29 corresponds here a direction of rotation of the tensioning wheel in FIG. 2 and 3 counterclockwise, which direction of rotation therefore hereinafter also referred to as "clamping direction 29". A Direction of rotation or swivel direction of the tensioning wheel 21 in the clockwise direction is always briefly referred to below as "opposite direction" and is marked with the reference number 30.

As already mentioned above, the tensioning wheel 21 can be pulled in by the motor 20 two directions of rotation 29 and 30 are driven. To this Purpose is the motor 20 via a gear 31 with the tensioning wheel 21 connected and transmits its drive torque via the toothed belt 22 from the motor driven pulley 32 to the main drive pulley 33 of the transmission 31, which is on the main drive shaft 34 of the gear 31 is seated, is rotatably mounted in the gear block 18 and carries a pinion toothing 35 at its inner end. The Pinion gear 35 is with two first planet gears 36 one two - stage planetary gear, of which in Fig. 4, however, only one is shown and which are in one Roll the internal toothing 37 of the gear housing 19 and thereby rotate a planet carrier 38 connected to them.

The planet carrier 38 rotates that which is firmly connected to it Central pinion 39 of the second stage of the planetary gear, which drives three more planet gears, which are in the gearbox 19 are mounted and turn the tensioning wheel 21, of which however only one 40 is shown. The tensioning wheel 21 is also mounted in the gear housing 19, overlaps with a Pot socket 41 and the other planet gears 40 via an internal toothing 42 of his pot socket 41 in engagement.

It can be seen from Fig. 4 that the tensioning wheel 21 on its outer Front surface has a hollow tensioning wheel pivot 43 with which pushed it onto an axle stub 44 of the gear housing 19 and turns on it. On this idler pin 43 is an eccentric 45 is rotatable with a freewheel in the clamping direction 29, mounted non-rotatably in the opposite direction 30. The eccentric in turn is guided by a steering lever 47, which is a second, fixed axis 48 is pivotally mounted in the clamping direction 29th to the right of the abutment 24 on the middle wall 15 of the base frame 13 is pivotally arranged. In Fig. 1 on the one hand and in the 2 and 3, on the other hand, are different ways of Connection between steering lever and eccentric shown. In the 1 has the eccentric to the tensioning wheel 21 concentric base plate 49 on which an eccentric pin is eccentric 50 is arranged in a corresponding to him Bore at the free end of the steering lever 47 is rotatable.

In contrast, in the embodiment shown in FIGS. 2 and 3 the steering lever 47 has a large, circular eye 51, in which there is a circular eccentric disc 52 can turn on with an eccentric bearing bore 53 the tensioning wheel pin 43 is rotatable.

The mode of operation of both versions is essentially the same and will be described in more detail below.

In both embodiments, the base plate 49 or Eccentric disc 52 the hinge side guide element already mentioned above 28, which is useful with this disc in one piece exists and is designed as a sector disk. The circular arc, outer edge 54 of the band side guide elements 28 protrudes beyond the peripheral surface 25 of the tensioning wheel and can be in a Enter recess 55 of base plate 14 of base frame 13 if they are together with the eccentric 45 in the clamping direction 29 rotates towards the abutment 13. To support this rotation, is a first pressure element 56, namely a torsion spring or a coil spring is provided, which strives to eccentric 45th to rotate in the tensioning direction 29 of the tensioning wheel 21. At her in Clamping direction 29 front edge 68 has the hinge side guide element 28 an inwardly leading chamfer 69, which is still a outwardly protruding tape end 11a and 11b into the tape channel 26 pushes when the sector disk rotates to the abutment.

It can be seen from Fig. 4 that in the drive shaft train 34,35,39 Gearbox, namely a second freewheel next to one of the main bearings 57 is provided in which the main drive shaft 34 can rotate freely when the tensioning wheel 21 in the tensioning direction 29 is driven, however, a reverse rotation of the drive shaft train 34,35,39 locks when the tension motor 20 when reached the desired belt tension remains. In this condition exerts the tensioned upper band end 11b on the tensioning wheel 21 a reverse torque in the opposite direction and it must be prevented be that the tensioning wheel turns back and thereby the band tension is loosened. This is done by locking the second freewheel 57 and the brake 58 reached.

In order to enable the tensioning motor 20 to run in reverse and via the drive shaft train 34, 35, 39 the tensioning wheel 21 also in the opposite direction 30 can be rotated, the brake 58 is designed so that a reverse rotation of the locked drive shaft train 34,35,39 is possible if the tension motor 20 runs backwards. This Brake 58 on the second freewheel 57 consists of one with the Freewheel hub 59 firmly connected brake disc 60 between Friction elements 61 and 62 runs, which are compressed by spring elements 63 become.

1 and 4 that the gear block 18 with the tensioning wheel 21 under the action of a second pressure element 64, namely a torsion spring that strives as a pivoting element is, the gear block 18 with the tensioning wheel 21 in the opposite direction 30 about the first, fixed axis 17 against the fixed To pivot abutment 24. With this swiveling movement it will Tensioning wheel 21 on its tensioning wheel pin 43 with the aid of the eccentric 45 and the steering lever 47, which form the guide means, guided, this pivoting movement also through the first Pressure element 56 is supported.

It can be seen from FIGS. 2 and 3 that on an extension 65 of the Gear housing 19 attached a forward nose 66 is that with a pivoting movement of the gear block 18 to the first, fixed axis 17 swings up and down and when swiveling up of the tensioning wheel against a stop 67 on the Middle wall 15 sets and thereby the pivoting movement of the tensioning wheel limited to its ineffective starting position.

The device works as follows:

In the starting position shown in Fig. 2, the Strap ends 11a and 11b of the strapping placed around a package 11 lying on top of each other from the right side in FIG Device 10 in the band channel 26 up to the inner band side guide 27 inserted and held. Then the Tension motor 20 with a switch button, not shown switched on forwards. The one from the engine driven pulley 32 driven by the toothed belt 22 main drive pulley 33 then rotates the main drive shaft 34 which in this forward run is not hindered by the second freewheel 57.

The planet gears 36 are driven by the pinion teeth 35, which are on the internal toothing 37 of the gear housing Roll off 19 and turn her tarpaulin support 38. This also causes the planet carrier 38 to rotate connected central pinion 39 and drives the planet gears 40, which in turn has the tensioning wheel 21 on its internal toothing 42 turn in clamping direction 29.

When the tensioning wheel 21 begins to rotate in the tensioning direction 29, the eccentric 45 is released from its inhibition and follows its bearing friction and under the pressure of the first pressure element 56 the tensioning wheel 21 in the tensioning direction 29. The eccentric rotates here in that shown in FIGS. 2 and 3 Embodiment in the bearing bore 53 of the steering lever 47 from the Starting position shown in Fig. 2 in that shown in Fig. 3 Working position, the steering lever 47 the tensioning wheel 21 in the opposite direction 30 around the first, fixed axis 17 on the abutment 24 swings down until the tensioning wheel with its profiled Circumferential surface 25 is placed on the upper band end 11b.

When the eccentric 45 rotates, it also pivots with it connected outer hinge side guide element 28 in the tensioning direction 29 down and at the same time covers the band channel 26 on his From the outside, so that the tape ends 11a and 11b when tensioning in Band channel 26 are performed on both side edges.

It can be seen that the rotation of the tensioning wheel 21 in Clamping direction 29 initiated pivoting movement of the gear block 18 is supported by the second pressure element 64, which the tensioning wheel 21 firmly against the band ends 11a and 11b and against the abutment 24 presses. The profiled peripheral surface 25 of the This causes the tensioning wheel to dig into the surface of the upper one Band end 11b, first climbs a little in the opposite direction 30 along until the increasing contact pressure the friction between the tensioning wheel 21 and the upper band end 11b becomes so great that it causes friction between the two ends of the belt 11a and 11b. The rotating tensioning wheel 21 pulls then the upper band end 11b in the tensioning direction over the lower one End of band 11a, which in this case from the profiled surface of the Abutment 24 is held.

As soon as the belt tension reaches the desired, predetermined value has reached, the tensioning motor 20 switches off automatically. The reverse torque generated by the band tension in the tensioning wheel 21, that through the drive shaft train 34,35,39 in the transmission 31st continues, activates the locking mechanism in the second freewheel 57, thereby due to the action of the brake 58, a reverse rotation of the tensioning wheel 21 is prevented.

The tape ends 11a and 11b can now in the welding device 12 are welded and cut in a manner known per se. Then the tensioning motor 20 is in reverse gear with the switch button switched and now drives via the main drive pulley 33 the main drive shaft 34 backwards. This one Direction of rotation is blocked by the second freewheel 57, must the effect of the brake 58 can be overcome. The driving force of the motor 20 is, however, so large that this is possible is. When reversing, the tensioning wheel is now via the gear 31 21 rotated in the opposite direction 30. Since also the first freewheel 46 locks in this direction of rotation, the eccentric 45 of the carried and rotates backward rotating idler pin 43 in the bearing bore 53 of the steering lever 47 also in the opposite direction 30 back into the starting position shown in FIG. 2. During this rotary movement, the gear block 18 of the steering lever 47 against the action of the second pressure element 64 pivoted counterclockwise until the Nose 66 hits the stop 67. The tensioning wheel 21 is then by the cogging torque of the tensioning motor 20 and / or by the the freewheels 46 and 57 inhibitions formed in the gear 31 and in the eccentric 45 in the starting position shown in Fig. 2 held. In this position, the clamping device 10 can then be pulled off the side of the closed strapping.

The invention is not based on that shown and described Embodiment limited, but there are several changes and additions possible without the scope of the invention leave. For example, as an inhibition instead of a freewheel a ratchet or a suitable brake is also used become. It is also possible to use other pivoting means Pressure elements such as pneumatic pressure accumulators or elastomer blocks to use. Finally, it is also possible instead of an electric motor to use an air motor and the motor according to an electronic program together with the welding and Control cutting device.

Claims (11)

1. Device (10) for tightening strapping bands (11), in particular of plastics, with an abutment (24) and with a tensioning wheel (21) provided with a return stop driven by a tensioning motor (20) by means of a gearing (31), which wheel forms a tensioning channel (26) with the abutment (24) for the band ends (11a and 11b) to be tightened and is arranged in a gearing block (18) with the tensioning motor (20) and the gearing (31) which is, as a whole, pivotally mounted around a first stationary axis (17) in the base frame (13) of the device (10) and which is held by holding means which are mounted with friction on a tensioning wheel pin (43) in its ineffective position lifted from the band end (11b) and is pivoted against the abutment (24) under the action of a (second) pressure element (64) when the tensioning wheel (21) starts in the tensioning direction (29) and the holding means loses its effective position, characterised in that the tensioning wheel (21) can be driven by the tensioning motor (20) in the tensioning direction (29) and in the opposite direction (30) and that the return stop is a (second) freewheel (57) with brake (58) which blocks the reverse rotation of the tensioning wheel (21) when the tensioning motor (20) stops, but which allows a reverse rotation of the tensioning wheel (21) when the tensioning motor reverses, and that the tensioning wheel (21) is mounted rotatably with its tensioning wheel pin (43) in an eccentric (45) with friction, which in turn is guided rotatably in a steering lever (47) which is pivotally mounted on a second stationary axis (48) on the base frame (13) and that a (first) freewheel (46) is arranged against the tensioning direction (29) between the tensioning wheel pin (43) and the eccentric (45).
2. Device according to claim 1, characterised in that the band ends (11a and 11b) are immediately on top of one another in the tensioning channel (26), whereby the lower band end (11a) is held in a non-positive manner by the surface of the abutment (24), while the upper band end (11b) is drawn along on the surface of the lower band end (11b) by the circumferential surface (25) of the tensioning wheel provided with a profile (23), and is tightened hereby around a package or the like.
3. Device according to claim 1 or 2, characterised in that the first stationary axis (17) of the gearing block (18) and the second stationary axis (48) of the steering lever (47) are arranged on different sides of the abutment (24).
4. Device according to one of claims 1 to 3, characterised in that the first stationary axis (17) of the gearing block (18) is arranged in the tensioning direction (29) in front of the abutment (24) and the second stationary axis (48) of the steering lever (47) is arranged behind the abutment (24).
5. Device according to one of claims 1 to 4, characterised in that the tensioning wheel (21) is guided by the eccentric (45) and the steering lever (47) in such a manner that it is pivoted against the abutment (24) during a rotation of the tensioning wheel (21) in the tensioning direction (29) in the opposite direction (30) and is lifted from the abutment (24) during a rotation of the tensioning wheel (21) in the opposite direction (30).
6. Device according to one of claims 1 to 5, characterised in that the eccentric (45) is under the action of a first pressure element (56) which strives to rotate the eccentric (45) in the tensioning direction (29) of the tensioning wheel (21).
7. Device according to one of claims 1 to 6, characterised in that the (second) freewheel (57) with brake (58) is arranged in the drive shaft train (34, 35, 39) of the gearing (31) for the tensioning wheel (21).
8. Device according to one of claims 1 to 7, characterised in that the brake (58) at the second freewheel (57) is a brake disc (60) connected to the freewheel hub (59), which disc runs between rigid friction elements (61, 62) pressed together by spring elements (63).
9. Device according to one of claims 1 to 8, characterised in that the tensioning wheel (21) is held in the ineffective position lifted from the band ends (11a and 11b) by the detent torque of the tensioning motor (20) and/or by the block in the (first) freewheel (46) of the eccentric (45) and/or by the block in the second freewheel (57) of the gearing (31).
10. Device according to one of claims 1 to 9, characterised in that the eccentric (45) is arranged on a band side guide element (28) rotatable around the tensioning wheel swivel pin (43) which element is under the action of the first pressure element (56) which rotates the band side guide element (28) in the tensioning direction to the extent that it covers the band channel (26) laterally when the tensioning wheel (21) is in its tensioning position pivoted down on the abutment (24).
11. Device according to claim 10, characterised in that the band side guide element (28) is a sector disc which comprises a chamfer (69) guided inwardly at the front edge (68) in the tensioning direction (29).

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