EP2285691B1 - Strapping device with a tensioner - Google Patents

Description

The invention relates to a strapping device, in particular mobile strapping device, for strapping packaged goods with a strapping, which has a clamping device for applying a belt tension on a loop of a strapping, a rotatably driven tensioning wheel and a pivotable relative to the tensioning wheel and cooperating with the tensioning wheel rocker, wherein a clamping plate for supporting a strapping band is arranged on the tensioning rocker, and a distance between the tensioning plate and the tensioning wheel for applying a tensioning force to the band is changeable, and a connecting device, in particular a welding device such as a friction welding device, for establishing a connection on two superimposed areas the loop of the strapping, has.

A strapping device in which a pivotable rocker can be pressed with a mounted on the rocker smooth clamping plate by means of a lever in the direction of the tensioning wheel of the strapping direction, for example, from the EP 0 480 627 A1 out. In the EP 0 997 377 A1 however, a rocker is pivotally mounted on a rigid base plate. On the rocker there are two counter-rollers, against which the band rests during the clamping process by means of the clamping device.

The US 4 015 643 discloses a strapping device in which in addition to the pivoting of the tensioning wheel, a variability of the relative position of the clamping plate with respect to the tensioning wheel can be generated by pivoting the clamping plate to compensate for different belt thicknesses.

In generic Umrelfungsvorrichtungen a rotatably drivable tensioning wheel cooperates with a toothed and usually concave clamping plate, which is arranged on a pivotable rocker. The rocker can be pivoted for the purpose of applying a clamping force on a belt loop in the direction of the tensioning wheel and pressed against the tensioning wheel. A pivot axis of the rocker does not coincide in this rule with the axis of rotation of the tensioning wheel. This allows "opening" and "closing" of the rocker with respect to the tensioning wheel, whereby the belt to be tensioned can be inserted in the strapping direction, grasped by the tensioning device and tensioned and subsequently removed again The lower belt layer is captured by the clamping plate of the rocker pivoted onto the tensioning wheel and is locked by its Surface structuring or other suitable means for generating a static friction held by the pressure exerted by the clamping plate on the lower band layer pressure on the clamping plate. This makes it possible by means of the then rotatively driven tensioning wheel to detect the upper band position and retreat. This causes or increases the belt tension in the belt loop and places the belt loop tightly around the respective packaged goods.

Such clamping devices are mainly used in conjunction with Kunststoffbändem whose loop are closed by a Reibschweissverbindung. Therefore, the strapping device has a Reibschweieinrichtung with which the belt loop in the region of the two superimposed band layers in the strapping device can be heated by means of an oscillating moving Reibschweisselements so far that the plastic tape melts locally, the material of the two band layers flows into each other and cohesively cohesively with each other combines.

It has now been found that in such clamping devices, the coatable tape tension can vary significantly, especially at different tape thicknesses. The invention is therefore an object of the invention to provide a strapping device of the type mentioned, with the same possible good clamping properties are achieved even with different tape thicknesses.

This object is achieved according to the invention in a strapping device of the type mentioned by the features of claim 1.

In the context of the invention, it has been recognized that at varying strip thicknesses a fluctuating sand tension is essentially due to the fact that the position of the clamping plate changes with respect to the tensioning wheel. As a result, depending on the respective strip thickness different engagement and pressure conditions between the two band layers on the one hand and the clamping plate and the tensioning wheel on the other. The invention therefore provides means for compensating the displacement of the intervention sites. This at least one means is a relative mobility of the clamping plate relative to the clamping rocker by a floating mounting of the clamping plate on the Spannwlppe. In addition, a variability of the position of the tensioning wheel could be provided in relation to the pivot axis of the rocker.

The proposed relative mobility of the clamping plate with respect to the rocker should be given in particular with respect to a direction by which a position of the clamping plate relative to the circumference of the tensioning wheel can be changed. This direction corresponds at least approximately to the longitudinal direction along which a strapping band inserted into the strapping device extends within the strapping device or the direction along which the straining plate moves due to the rocker movement. Such an embodiment has the advantage that the contact pressure, in particular a substantially uniformly distributed contact pressure, is made possible by the clamping plate on the band or band on the tensioning wheel, regardless of the respective band thickness over substantially the entire length of the clamping plate.

The engagement conditions can be further improved even for different strip thicknesses alternatively or in addition to the mobility of the clamping plate in that the clamping plate is concavely curved with a radius that advantageously at least approximately corresponds to the outer radius of the tensioning wheel or can be slightly larger. By such a concave configuration of the clamping surface helps during clamping between the clamping surface of the clamping plate and the outer surface of the tensioning wheel over preferably the entire length of the clamping surface - with respect to the clamping direction - to provide a gap with at least approximately constant gap height.

In contrast to the solution according to the invention in the previous solution, a distribution of the contact pressure on a surface portion of the strap substantially only at a certain strip thickness is possible, through which the rocker has assumed a position in which the curvature of the clamping plate is parallel to the circumference of the clamping radius. The resulting between the tensioning wheel and the clamping plate gap thus had only at a certain strip thickness over the entire length of the clamping plate constant gap height. The more the tape thickness deviated from this one suitable tape thickness, the smaller was the area on which the clamping plate or the tensioning wheel could act both in the lower and in the upper band position. By contrast, with the embodiment according to the invention it is now possible for the different pivoting positions of the rocker in relation to the tensioning wheel resulting from different band thicknesses to be so compensate that despite the then different positions of the clamping rocker, the clamping plate can be substantially always aligned so that over the entire length of the clamping plate, a gap results in substantially constant gap height, at least with a lower gap height variation than in conventional solutions. This allows over the entire length of the clamping plate a more uniform pressure application to the strapping band than before.

The solution according to the invention shows in particular strong in small packages (edge length of about 750mm and smaller) and in round packages (diameter about 500mm - 1000mm) in conjunction with high clamping forces advantages. Under these circumstances, the then relatively small belt loop when tightening to a shock-like load of the lower belt layer, ie the end of the tape, out, through which the lower belt ply is pulled against the clamping plate. Due to very different pressure conditions over the entire length of the clamping plate, a secure holding of the band end in the strapping device could not be guaranteed in previous solutions. The movable clamping plate has here decisive advantages, which are essentially in the fact that even with shock-like clamping loads in conjunction with high clamping forces, the bands can be held by the optimal due to their mobility aligned tooth plate.

In a preferred erfindunsgemässen embodiment, the relative mobility of the clamping plate can be realized by a bearing of the clamping plate on the rocker using non-mutually parallel bearing surfaces of the clamping plate. According to this principle can be provided in particular that the clamping plate is provided with a convex contact surface which rests on a substantially flat support surface of the rocker. This allows a tilting of the clamping plate, whereby a self-alignment and nestling of the clamping plate can be made to the periphery of the tensioning wheel. In a preferred embodiment, measures can also be provided by which a self-alignment of the clamping plate in a direction transverse to the strip can be achieved. Such a measure may for example be a convex course of the bearing surface of the clamping plate and transverse to the belt.

A further advantageous embodiment according to the invention can provide that the clamping plate is provided with a guide, which results in a mobility in one or more predetermined directions. The guiding direction may in particular be a direction which is aligned at least substantially parallel to the strip course within the strapping device. Furthermore, in an expedient embodiment of the guide for the clamping plate by means of a slot and a guide means arranged therein, such as a screw can be formed.

Further preferred embodiments of the invention will become apparent from the claims, the description and the drawings.

Fig. 1

eine perspektivische Darstellung einer erfindungsgemässen Umreifungs vorrichtung;

Fig. 2

das Umreifungsgerät aus Fig. 1 ohne Gehäuse;

Fig. 3

eine teilweise geschnittene Darstellung des Motors der Umreifungsvorrichtung aus Fig. 1 zusammen mit auf der Motorwelle angeordneten Komponenten;

Fig. 4

eine stark schematisierte Darstellung des Motors zusammen mit seiner elektronischen Schaltung zur Kommutierung;

Fig. 5

eine perspektivische Teildarstellung des Antriebsstrangs des Umreifungsgeräts aus Fig. 1;

Fig. 6

der Antriebsstrang aus Fig. 5 in einer Darstellung aus einer anderen Blickrichtung;

Fig. 7

eine Seitenansicht des Antriebsstrangs aus Fig. 5 mit der Schweißeinrichtung in einer Ruheposition;

Fig. 8

eine Seitenansicht des Antriebsstrangs aus Fig. 5 mit der Schweißeinrichtung in einer Position zwischen zwei Endpositionen;

Fig. 9

eine Seitenansicht des Antriebsstrangs aus Fig. 5 mit der Schweißeinrichtung in einer Schweissposition.

Fig. 10

eine Seitenansicht auf die Spanneinrichtung des Umreifungsgerätes ohne Gehäuse, in der sich eine Spannwippe in einer Ruhestellung befindet;

Fig. 11

eine Seitenansicht auf die Spanneinrichtung des Umreifungsgerätes ohne Gehäuse, in der sich eine Spannwippe in einer Spannstellung befindet;

Fig. 12

die teilweise geschnitten dargestellte Spannwippe des Umreifungsgerätes aus Fig. 10 in einer Seitenansicht;

Fig. 13

die Spannwippe aus Fig. 12 in einer Frontansicht;

Fig. 14

ein Detail aus Fig. 12 gemäss der Linie C - C.

The invention will be explained in more detail with reference to embodiments shown purely schematically in the figures, in which:

Fig. 1

a perspective view of an inventive strapping device;

Fig. 2

the strapping device off Fig. 1 without housing;

Fig. 3

a partially sectioned view of the motor of the strapping from Fig. 1 together with components arranged on the motor shaft;

Fig. 4

a highly schematic representation of the engine together with its electronic circuit for commutation;

Fig. 5

a partial perspective view of the drive train of the strapping device Fig. 1 ;

Fig. 6

the powertrain off Fig. 5 in a representation from another perspective;

Fig. 7

a side view of the drive train Fig. 5 with the welding device in a rest position;

Fig. 8

a side view of the drive train Fig. 5 with the welding device in a position between two end positions;

Fig. 9

a side view of the drive train Fig. 5 with the welding device in a welding position.

Fig. 10

a side view of the clamping device of the strapping device without housing, in which a clamping rocker is in a rest position;

Fig. 11

a side view of the clamping device of the strapping device without housing, in which a clamping rocker is in a clamping position;

Fig. 12

the partially cut illustrated rocker of the strapping Fig. 10 in a side view;

Fig. 13

the tilting rocker Fig. 12 in a front view;

Fig. 14

a detail from Fig. 12 according to the line C - C.

That in the Fig. 1 and 2 shown, exclusively hand-operated inventive strapping device 1 has a housing 2, which surrounds the mechanism of the strapping device and on which a handle 3 for handling the device is formed. The strapping apparatus is further provided with a base plate 4, the underside of which is provided for placement on an object to be packaged. On the base plate 4 and connected to the base plate not shown carrier of the strapping device all functional units of the strapping device 1 are attached.

With the strapping device 1, a in Fig. 1 not shown loop of a plastic tape, for example, polypropylene (PP) or polyester (PET)), which was previously placed around the object to be packaged, are tensioned by means of a tensioning device 6 of the strapping device. The clamping device has for this purpose a tensioning wheel 7, with which the band can be detected for a clamping operation. The tensioning wheel 7 acts together with a rocker 8, which can be pivoted by means of a rocker arm 9 from an end position with distance to the tensioning wheel in a second end position about a rocker pivot axis 8a, in which the rocker 8 is pressed against the tensioning wheel 7. Also located between the tensioning wheel 7 and the rocker 8 band is in this case pressed against the tensioning wheel 7. By rotation of the tensioning wheel 7, it is then possible to provide the belt loop with a sufficiently high for the packaging purpose tape tension. The process of clamping and this purpose advantageously trained rocker 8 will be explained in more detail below.

Subsequently, a welding of the two layers by means of the friction-welding device 8 of the strapping device can take place at one point of the belt loop on which two layers of the belt lie one above the other. The strap loop can thereby be permanently closed. For this purpose, the friction-welding device 10 is provided with a welding shoe 11, which melts the two layers of the strapping band by mechanical pressure on the strapping band and a simultaneous oscillating movement with a predetermined frequency. The plasticized or molten areas flow into each other and after cooling of the band then creates a connection between the two band layers. If necessary, then the belt loop can be separated from a supply roll of the tape by means of a cutting device of the strapping device 1, not shown.

The actuation of the tensioning device 6, the delivery of the friction-welding device 10 by means of a transfer device 19 (FIG. Fig. 6 ) of the friction-welding device 10 as well as the use of the friction-welding device per se and the operation of the cutting device are carried out using only a common electric motor 14, which provides a drive movement for each of these components. To the power supply is on the strapping a replaceable and arranged in particular for charging removable accumulator 15. A supply of other external auxiliary energy, such as compressed air or other electricity, is in the strapping apparatus according to the Fig. 1 and 2 not provided.

In the present case, the portable mobile strapping device 1 has a trained as a pressure switch actuator 16, which is provided for commissioning of the motor. For the actuating element 16 17 three modes can be adjusted by means of a switch. In the first mode, both the tensioning device 6 and the friction-welding device 10 are actuated successively and automatically by actuation of the actuating element 16 without the need for further operator activity. To set the second mode, the switch 17 is switched to a second switching mode. In the second possible mode, only the tensioning device 6 is then released by actuating the actuating element 16. For separate triggering of the friction-welding device 10, a second actuating element 18 must be actuated by the operator. In alternative embodiments, it may also be provided that in this mode for triggering the friction-welding device, the first actuating element 16 is to be actuated a second time. The third mode is a kind of semiautomatic, in which the tension button 16 is to be pressed until the prestressed tension or tensile stress in the belt is reached. In this mode, it is possible to interrupt the clamping process by releasing the tensioning button 16, for example, to attach edge protectors to the Umreifungsgut under the strapping. By pressing the tension button, the clamping process can then be resumed. This third mode can be combined with a separately triggered as well as with an automatically subsequent friction welding process.

On a in Fig. 3 shown motor shaft 27 designed as a brushless, grooved female rotor DC motor 14, a transmission device 13 is arranged. In the embodiment shown here, a motor of the company. Maxon Motor AG, Brünigstrasse 20, 6072 Sachseln, type ECI40 is used. The brushless DC motor 14 can be operated in both directions of rotation, with one direction of rotation being used as the drive movement of the clamping device 6 and the other direction of rotation being used as the drive movement of the welding device 10.

The in Fig. 4 brushless DC motor 14 shown purely schematically is formed with a grooved internal rotor (rotor) 20 with three Hall sensors HS1, HS2, HS3. This EC motor (electronically commutated motor) has a permanent magnet in its rotor 20 and is provided with an electronic control 22 which is provided for electronic commutation in the stator 24. The electronic controller 22 determines via the Hall sensors HS1, HS2, HS3, which also assume the function of position sensors in the embodiment, the respective instantaneous position of the rotor 20 and switches the electric magnetic field in the windings of the stator 24. Thus, the phases (Phase 1, Phase 2, Phase 3) are switched in response to the position of the rotor 20 to cause a rotational movement of the rotor in a certain direction of rotation, with a predeterminable variable speed and torque. In the present case, a so-called "1 quadrant motor drive amplifier" is used, which provides the motor with the voltage, as well as peak and continuous current available and controls. The current flow for not shown coil strands of the stator 24 is controlled by a bridge circuit 25 (MOSFET transistors), ie commutated. Furthermore, a not further shown temperature sensor is provided on the engine. It is thus possible to monitor and control the direction of rotation, the speed of rotation, the current limit and the temperature. The commutation is constructed as a separate print component and accommodated in the strapping device separately from the motor.

The power supply is ensured by the trained as a lithium-ion battery accumulator 15. Such rechargeable batteries are based on a number of independent lithium-ion cells, in each of which at least substantially independently chemical processes for generating a potential difference between two poles of the respective cell take place. In the exemplary embodiment is a lithium-ion battery manufacturer Robert Bosch GmbH, D-70745 Leinfelden-Echterdingen. The battery of the embodiment has eight cells and has a capacity of 2.6 ampere hours. As an active material or as a negative electrode of the lithium-ion battery graphite is provided. The positive electrode of the accumulator often has lithium metal oxides, in particular in the form of layer structures. The electrolyte used is usually anhydrous salts, such as lithium hexafluorophosphate or polymers. The one by one conventional lithium-ion battery delivered voltage is usually 3.6 volts. The energy density of such accumulators is about 100 Wh / kg - 120 Wh / kg.

The transmission device 13 has a freewheel 36 arranged on the motor-side drive shaft, on which a sun gear 35 of a first planetary gear stage is arranged. The freewheel 36 is only in one of the two possible directions of rotation of the drive, the rotational movement of the sun gear 35 on. The sun gear 35 meshes with three Planentenrädern 37, which are in a conventional manner in engagement with a fixed ring gear 38. Each of the planet gears 37 is in turn arranged on a respective shaft 39 associated therewith, which is in each case integrally connected to a driven gear 40. The rotation of the planet gears 37 about the motor shaft 27 results in a rotational movement of the driven gear 40 about the motor shaft 27 and determines a rotational speed of this rotational movement of the output gear 40. In addition to the sun gear 35, the output gear 40 is located on the freewheel 36 and is therefore also on the motor shaft stored. This freewheel 36 causes both the sun gear 35 and the output gear 40 rotate only in one direction of rotation of the rotational movement of the motor shaft 27. The freewheel 29 may for example be of the type INA HFL0615, as offered by the company Schaeffler KG, D-91074 Herzogenaurach.

The gear device 13 has on the motor-side output shaft 27 also a belonging to a second planetary gear toothed sun gear 28, through the recess while the shaft 27 is performed, in this case, the shaft 27 is not connected to the sun gear 28. The sun gear is fixed to a disc 34, which in turn is connected to the planetary gears 37. The rotational movement of the planetary gears 37 about the motor-side output shaft 27 is thus transmitted to the disc 34, which in turn transmits its rotational motion identical to the sun gear 28. The sun gear 28 meshes with a plurality of planet gears, namely three, each arranged on a parallel to the motor shaft 27 extending shaft 30 gears 31. The shafts 30 of the three gears 31 are fixedly arranged, ie they do not rotate about the motor shaft 27. The three gears 31 are in turn with an internally toothed ring gear engaged on its outer side has a cam 32 and subsequently as Cam wheel 33 is designated. The sun gear 28, the three gears 31 and the cam 33 are components of the second planetary gear stage. The planetary gear on the input side Rotationsbewegegung the shaft 27 and the rotational movement of the cam wheel 33 are in a ratio of 60: 1, ie by the two-stage planetary gear is a 60-fold reduction takes place.

At the end of the motor shaft 27, a bevel gear 43 is also arranged on a second freewheel 42, which is in engagement with a second bevel gear, not shown. This freewheel 42 also transmits only in one direction of rotation of the motor shaft 27, the rotational movement. The direction of rotation, in which the freewheel 36 of the sun gear 35 and the freewheel 42 transmit the rotational movement of the motor shaft 27 are opposed to each other. This means that in one direction of rotation rotates only the freewheel 36 and in the other direction only the freewheel 42 with.

The second bevel gear is arranged at one end of a clamping shaft, not shown, which carries at its other end another planetary gear 46 ( Fig. 2 ). The drive movement of the electric motor in a certain direction of rotation is thus transmitted to the two bevel gears 43 to the clamping shaft. By means of a sun gear 47 and three planetary gears 48, the tensioning wheel 49 of the tensioning device 6 designed as an internally toothed ring gear is thereby set in rotation. The provided on its outer surface with a surface structure tensioning wheel 7 takes in its rotational movement, the respective strap through a frictional engagement, whereby the intended belt tension is applied to the belt loop.

The output gear 40 is formed in the region of its outer peripheral surface as a gear on which a toothed belt 50 of an envelope drive is arranged ( Fig. 5 and Fig. 6 ). The toothed belt 50 also wraps around a relative to the output gear 40 in diameter smaller pinion 51, whose shaft drives an eccentric 52 for an oscillating reciprocating movement of the welding shoe 53. Instead of a toothed belt drive and any other form of enveloping drives could be provided, such as a V-belt or chain drive. The eccentric drive 52 has an eccentric shaft 54, on which an eccentric 55 is arranged, on which in turn sits a welding shoe arm 56 with a circular recess. The eccentric Rotational movement of the eccentric 55 about the rotation axis 57 of the eccentric shaft 54 leads to a translational oscillating reciprocating motion of the welding shoe 53. Both the eccentric drive 52 and the welding shoe 53 itself can also be formed in any other manner known per se.

The welding device is further provided with a toggle device 60, by means of which the welding device is moved from a rest position (FIG. Fig. 7 ) in a welding position ( Fig. 9 ) can be transferred. The toggle device 60 is attached to the welding shoe arm 56 and in this case provided with a pivotable on Schweissschuharm 56 longer toggle lever 61. The toggle device 60 is further provided with a pivotable about a pivot axis 62 pivoted pivot member 63 which acts in the toggle lever 60 as a shorter toggle. The pivot axis 62 of the pivot member 63 in this case runs parallel to the axes of the motor shaft 27 and the eccentric shaft 57th

The pivotal movement is initiated by means of the cam 32 of the cam wheel 33, which in the counterclockwise rotation in the rotation - based on the representations of Fig. 7 to 9 - the cam wheel 33 passes under the pivot member 63 ( Fig. 8 ). A ramp-like rising surface 32a of the cam 32 in this case touches an inserted into the pivot member 63 contact element 64. The pivot member 63 is thereby rotated clockwise about its pivot axis 62. In the area of a concave recess of the pivoting element 63, a two-part longitudinally adjustable toggle lever rod of the toggle lever 61, which is in two parts according to the principle "piston-cylinder", is arranged pivotable about a pivot axis 69. The latter is also rotatably articulated to a pivot axis 65 designed as a further pivot point 65 of the welding shoe arm 56 in the vicinity of the welding shoe 53 and at a distance from the pivot axis 57 of the welding shoe arm 56. Between the two ends of the longitudinally variable toggle rod, a compression spring 67 is arranged on this, by means of which the toggle lever 61 is pressed both against the welding shoe arm 56 and against the pivoting element 63. The pivoting member 63 is thus operatively connected with the toggle lever 61 and the welding shoe arm 56 with respect to its pivotal movements.

As in the representations of FIGS. 7 and 9 can be seen, is located in the rest position by a toggle lever 61 extending (imaginary) connecting line 68 of the two articulation points of the toggle lever 61 between the pivot axis 62 of the pivot member 63 and the cam wheel 33, ie on one side of the pivot axis 62. By pressing of the cam wheel 33, the pivot member 63 - with respect to the representations of Fig. 7 to 9 - Turned clockwise. Here, the toggle lever 61 is taken from the pivot member 63 with. In Fig. 8 an intermediate position of the toggle lever 61 is shown, in which the connecting line 68 of the articulation points 65, 69, the pivot axis 62 of the pivot member 63 intersects. In the in Fig. 9 The knee lever 61 is then with its connecting line 68 with respect to the cam wheel 33 and the rest position on the other side of the pivot axis 62 of the pivot member 63. In this movement, the Schweißschuharm 56 by the toggle lever 61 of his Rest position transferred by rotation about the pivot axis 57 in the welding position. In the latter, the compression spring 67 presses the pivot member 63 against a stop, not shown, and the welding shoe 53 on the two tape layers to be welded together. The toggle lever 61 and thus also the welding shoe arm 56 is thus in a stable welding position.

The in the representation of Fig. 6 and 9 counterclockwise driving movement of the electric motor is transmitted from the timing belt 50 to the now transferred by the toggle lever 60 in the welding position welding shoe 53, which is pressed on the two band layers and moves back and forth in an oscillating motion. The welding time for generating a Reibschweissverbindung is determined by the fact that the adjustable number of revolutions of the cam wheel 33 is counted from the time from which the cam 32, the contact element 64 is actuated. For this purpose, the number of revolutions of the shaft 27 of the brushless DC motor 14 is counted to determine the position of the cam wheel 33, from which the engine 14 is turned off and thus the welding process is to be terminated. In this case, it should be avoided that when stopping the engine 14, the cam 32 stops below the contact element 64. For stopping the motor 14, therefore, only relative positions of the cam 32 are provided with respect to the pivot member 63, in which the cam 32 is not located below the pivoting element. This ensures that the welding shoe arm 56 is returned from the welding position to the rest position (FIG. Fig. 7 ) can pivot. In this way, in particular a position of the cam 32 is avoided, in which the cam 32 would arrange the toggle lever 61 in a dead center position, ie in a position in which the connecting line 68 of the two articulation points, the pivot axis 62 of the pivoting element 63 - Fig. 8 shown - cuts. Since such a position is avoided, now by means of an actuation of the rocker lever, the rocker ( Fig. 2 ) Loosened from the tensioning wheel 7 and in this case also the toggle lever 61 in the direction of the cam wheel 33 in the in Fig. 7 be pivoted position shown. After the strap loop is removed from the strapping, the latter is ready for another strapping process.

The described successive processes "clamping" and "welding" can be triggered jointly in a switching state of the actuating element 16. For this purpose, the actuating element 16 is to be actuated once, whereby the electric motor 14 first runs in the first direction of rotation and in this case (exclusively) the tensioning device 6 is driven. The band tension to be applied to the respective band can preferably be set on the strapping apparatus by means of a pushbutton in nine stages which correspond to nine different band tension values. Alternatively, a continuous adjustment of the belt tension could be provided. Since the motor current from the torque of the tensioning wheel 7 and this in turn depends on the instantaneous belt tension, the applied belt tension can be adjusted in the form of a limit of the motor current via push buttons in nine stages on the control electronics des.Umreifungsgeräts.

After reaching an adjustable and thus predeterminable limit value for the motor current or for the belt tension, the motor 14 is turned off by its controller 22. Immediately thereafter, the motor is operated by the controller 22 in the reverse direction of rotation. As a result, in the manner described above, the welding shoe 53 is lowered onto the two superposed belt layers and the oscillating movement of the welding shoe is carried out to produce the friction-welded connection.

By actuating the switch 17, the actuating element 16 can be occupied only with the function of the triggering the clamping device. If such a setting is made, only the clamping device is put into operation by pressing the actuator and turned off again after reaching the preset belt tension. In order to trigger the Reibschweissvorgang the second actuator 18 must be actuated. However, apart from the separate triggering, the function of the friction welding device is identical to the other mode of the first actuating element.

As already explained above, the rocker 8 by pressing the in the Fig. 2 . 10 . 11 illustrated rocker lever 9 pivoting movements to perform about the rocker axis 8a. The rocker is this purpose by means of a behind the tensioning wheel 7 and therefore in Fig. 2 unrecognizable, rotatable cam moves. About the rocker lever 9, the cam can perform a rotational movement of about 30 ° and move the rocker 8 and clamping plate 12 relative to the tensioning wheel 7, which allows insertion of the tape in the strapping or between the tensioning wheel 7 and clamping plate 12.

In this way, the arranged in the region of the free end of the rocker on the latter toothed clamping plate 12 of a in Fig. 10 shown rest position in one Fig. 11 resulting clamping position and be pivoted back again. In the rest position, the clamping plate 12 has a sufficiently large distance to the tensioning wheel 7, so that a strapping between the tensioning wheel and the clamping plate can be arranged in two layers, as is required for the formation of a closure on a belt loop. In the clamping position, the clamping plate 12 is pressed in a conventional manner, for example by means of a force acting on the rocker spring force against the tensioning wheel 7, wherein different than in Fig. 11 represented, in a strapping process, the two-ply tape between the clamping plate and the tensioning wheel and thus should take place between the two latter no contact. The tensioning wheel 7 facing toothed surface 12a (clamping surface) is concavely curved, wherein the radius of curvature corresponds to the radius of the tensioning wheel 7, or is slightly larger.

As in particular in the Fig. 10 and 11 as well as in the detailed representations of the Fig. 12 - 14 can be seen, the toothed clamping plate 12 is arranged in a groove-shaped recess 71 of the rocker. In addition, the clamping plate 12 is provided with a convexly curved contact surface 12 b, with which it is mounted in the recess 71 of the rocker 8 on a flat bearing surface 72 is. As can be seen in particular from the Fig. 11 and 12 results, the convex curvature in a direction parallel to the belt running direction 70, while the contact surface 12b formed transversely to this direction ( Fig. 13 ). Due to this configuration, the clamping plate 12 is able to perform in the position in the band running direction 70 relative to the rocker 8 and the tensioning wheel 7 tilting movements. Furthermore, the clamping plate 12 is fastened to the rocker 8 with a screw 73 carried out from below by the rocker. For this purpose, the screw is located in a slot 74 of the rocker, whose longitudinal extent runs parallel to the band path 70 in the strapping device. The clamping plate 12 is thereby additionally arranged longitudinally displaceable on the rocker 8 in addition to the tiltability.

In a clamping operation, first, the clamping rocker 8 from the rest position ( Fig. 10 ) in the clamping position ( Fig. 11 ). In the clamping position, the spring-loaded rocker 8 presses the clamping plate 12 in the direction of the tensioning wheel and clamps both tape layers between the tensioning wheel 7 and the clamping plate 12. Due to different strip thicknesses, different distances between the clamping plate 12 and the circumferential surface 7a of the tensioning wheel 7 can result. This not only different pivoting positions of the rocker 8 result, but also different position of the clamping plate 12 with respect to the circumferential direction of the tensioning wheel 7. To still achieve uniform contact pressure, the clamping plate 12 is directed during the pressing of the tape by a longitudinal movement in the recess 71 and a tilting movement on the contact surface 12b on the support surface 72 independently so that the clamping plate 12 exerts over its entire length as uniform as possible pressure on the strapping. Now, if the tensioning wheel 7 is turned on, the teeth of the clamping plate 12 holds the lower band position, while the tensioning wheel 7 detects the upper band position with its toothed peripheral surface 7a. The rotation movement the tensioning wheel 7 and the lower coefficient of friction between the two band layers then causes the tensioning wheel to retract the upper band ply and thus increase the tension in the band loop to the desired tension value. <B> LIST OF REFERENCES </ b> 1 Strapping device 1 30 wave 2 casing 31 gear 3 Handle 32 cam 4 baseplate 32a area 6 tensioning device 33 cam 7 tensioning wheel 35 sun 7a peripheral surface 36 freewheel 8th seesaw 37 planet 8a Rocker pivot axis 38 ring gear 9 rocker lever 39 wave 10 friction welder 40 output gear 11 welding shoe 42 freewheel 12 chipboard 43 bevel gear 12a clamping surface 46 planetary gear 12b contact area 47 sun 13 transmission device 48 planet 14 electric DC motor 49 tensioning wheel 15 accumulator 50 toothed belt 16 actuator 51 pinion 17 switch 52 eccentric 18 actuator 53 welding shoe 19 Transfer device 54 eccentric shaft 20 rotor 55 eccentric HS1 Hall sensor 56 Welding shoe arm HS2 Hall sensor 57 Rotation axis eccentric shaft HS3 Hall sensor 60 Toggle lever device 22 electronic control 61 longer toggle 24 stator 62 swivel axis 25 bridge circuit 63 pivoting element 27 motor-side output shaft 64 contact element 28 sun 65 swivel axis 66 swivel axis 72 bearing surface 67 compression spring 73 screw 68 connecting line 74 Long hole 69 swivel axis 70 Band-running direction 71 recess

Claims (10)

1. Strapping device, in particular a mobile strapping device, for strapping packaged goods with a strapping band, having a tensioning unit (6) for applying band tensioning to a loop of a strapping band, which tensioning unit (6) has a rotatingly drivable tensioning wheel (7) and a tensioning compensator (8) which is pivotable in relation to the tensioning wheel (7) and interacts with the tensioning wheel (7), wherein a tensioning plate (12) for bearing a strapping band is disposed on the tensioning compensator (8), and spacing between the tensioning plate (12) and the tensioning wheel (7) for applying a tensioning force on the band is modifiable, and having a connection unlit, in particular a welding unit, such as a friction-welding unit (10), for creating a connection on two regions of the loop of the strapping band which lie on top of one another,
   characterized
   by means by which, in addition to the pivotability of the tensioning compensator (8), modifiability of the relative position of the tensioning plate (12) in relation to the tensioning wheel (7) by way of a floating mounting of the tensioning plate (12) on the tensioning compensator (8) is creatable.
2. Mobile strapping device according to Claim 1, characterized in that the tensioning plate (12) is movably mounted on the tensioning compensator (8).
3. Mobile strapping device according to Claim 2, characterized in that the tensioning plate (12) is mounted on the tensioning compensator so as to be longitudinally movable in at least one direction in relation to the tensioning compensator (8).
4. Mobile strapping device according to Claim 3, characterized by a slot-type recess (71, 74) for fastening the tensioning plate (12) on the tensioning compensator (8) in a longitudinally movable manner.
5. Mobile strapping device according to at least one of the preceding claims, characterized by a contact face which is curved in a convex manner and by which the tensioning plate is mounted on the tensioning compensator.
6. Mobile strapping device according to at least one of the preceding claims, characterised by wobbling mounting of the tensioning plate on the tensioning compensator.
7. Mobile strapping device according to at least one of the preceding claims, characterized by means by which during the tensioning operation the tensioning compensator is stressable by force in the direction of the tensioning wheel.
8. Mobile strapping device according to at least one of the preceding claims, characterized in that a tensioning face of the tensioning plate which is provided for contact with a strapping band has a concave curvature.
9. Mobile strapping device according to Claim 8, characterized in that a radius of curvature of the tensioning face is equal to or larger than a radius of a circumferential face of the tensioning wheel.
10. Mobile strapping device according to at least one of the preceding claims, characterized by a chargeable energy accumulator for storing energy, in particular electrical, mechanical, elastic or potential energy which, for creating the connection, is releasable as driving energy at least for the connection unit.

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