EP2280875B1 - Strapping device with a gear system device - Google Patents

Abstract

A mobile strapping device for strapping packaged goods with wrap-around strap comprises a tensioner (6) for applying a strap tension to a loop of a wrapping strap, and a friction welder (10) for producing a friction weld connection by way of a friction welding element at two areas of the loop of the wrapping strap disposed one on top of the other, and a chargeable energy storage means (15) for storing electrical energy that can be released as drive energy for motorized drive motions at least for the friction welder for producing a friction weld connection. In order for such a strapping device to have high functional reliability and ease of handling, despite the possibility of automated production of wrapped straps, at least to a large extent, it is proposed for the strapping device to comprise a planetary gear system (35, 37, 38) for transferring and changing the rotational speed of a drive motion provided by an electrical drive of the friction welder.

Description

The invention relates to a mobile strapping device for strapping packaged goods with a strapping band, which comprises a tensioning device for applying a belt tension to a loop of a strapping belt, and a friction welding device for generating a Reibschweissverbindung on two superimposed areas of the loop of the strapping, and a rechargeable energy storage for storage of electrical energy which is releasable as drive energy at least for the friction-welding device for generating a friction-welded connection.

Such mobile strapping device are used for strapping of packaged goods with a plastic tape. For this purpose, a loop of the respective plastic strip is placed around the packaged goods. In general, the plastic tape is hereby deducted from a supply roll. After the loop is completely wrapped around the packaged goods, the end portion of the band overlaps with a portion of the band loop. The strapping device is then applied to this two-layer region of the band, in which case the band is clamped in the strapping device, a band tension is applied to the band loop by means of the tensioning device, and a closure is produced by friction welding to the loop between the two band layers. In this case, the belt loop is pressed onto the belt with an oscillatingly moving friction shoe in the region of two ends. The pressure and the heat generated by the movement melts the usually plastic-containing band locally for a short time. This creates between the two band layers a permanent and at most with great force again to be solved connection between the two band layers. Thereafter, the loop is separated from the supply roll. The respective packaged goods are thereby strapped.

Generic strapping devices are provided for mobile use, in which the devices carried by a user to the respective site and should not rely on the use of externally supplied supply energy. The energy required for the intended use of such strapping tools for tensioning a strapping band around any packaged goods and for Closure generation is provided in prior art strapping devices usually by an electric accumulator or by compressed air available. Generic mobile strapping devices are often used in industry for the packaging of goods in continuous use. It is therefore desirable as simple as possible operation of the strapping devices. In this way, on the one hand, a high level of functional reliability of the strapping device and, on the other hand, the lowest possible loads for the servants should be ensured. There are therefore already known strapping devices in which the closure generation and generation of the belt tension run largely automated.

So is out of the EP 1 413 519 A a mobile strapping apparatus is known, which is provided with a tensioning device for applying a tension on the strapping band and with a welding device. The welding device is designed as a friction welding device in which an oscillating movement of a welding shoe on the strap laterally melts the latter and welds the belt layers of the strap together. To achieve such melting, certain frequencies and speeds of the oscillating movement of the welding shoe are required. This will be at the EP 1 413 519 A provided by means of an electric motor, the movement of which is transmitted to a transmission which converts the motor drive movement into an oscillating movement.

The EP 0 997 377 A describes a mobile strapping apparatus in which an electric motor is the starting point for the oscillating movement of a welding shoe. The rotary drive movement of the electric motor is transformed via an eccentric and a lever mechanism into an oscillating movement of the welding shoe. The EP 0 997 377 also describes a use of a planetary gear as a transmission for a tensioning drive, in which the tensioning wheel is driven continuously in one direction of rotation.

However, the automation of processes in the production of strapping has the disadvantage that the strapping devices a variety of components and in usually also have multiple engines. This leads to heavy and voluminous strapping tools. In addition, strapping devices provided with a plurality of components tend to be top-heavy with respect to their weight distribution. Finally, the automation also leads to disadvantages in terms of maintenance and reliability of such strapping.

The invention is therefore an object of the invention to provide a generic mobile strapping device of the type mentioned, which despite the possibility of at least largely automated generation of tape strapping has a high reliability and good handling properties.

This object is achieved in a mobile strapping apparatus according to the preamble of claim 1 according to the invention by a planetary gear for transmission and speed variation of a provided by an electric drive of the friction welding drive movement. According to the invention, the strapping device has at least one planetary gear, which is located in the drive train of the friction welding device. It has been found that planetary gear in combination with an electric drive motor bring particular advantages in Reibschweisseinrichtungen with it. Thus, high torques can be delivered with planetary gearboxes despite high input speeds and a compact design.

This can be used with advantage in particular also for particularly functionally reliable, automated as possible transfer movement of the friction-welding device from a rest position to a welding position in which the friction-welding device abuts against the band to be welded and generates a friction-welded closure by means of oscillating motion. This can be particularly advantageous if - as is the case with particularly advantageous embodiments according to the invention - both the actual friction-welding movement of a friction-welding element and the transfer movement are generated with the same drive. Such an embodiment with only one drive for these functions is despite a high degree of automation particularly compact and functionally reliable with favorable weight distribution.

These advantages can be further increased by embodiments according to the invention in which the same drive which is provided for generating the oscillating friction-welding movement also generates the clamping movement of the clamping device. In order to form the clamping device as compact as possible despite high torque, a planetary gear can also be arranged in the drive train for the clamping device.

According to a further aspect of the present invention, which also has independent significance, the strapping device is provided with a brushless DC motor. This motor can be provided in particular as the only motor in the strapping device. Unlike brush-based DC motors, such a motor can deliver rotational motion with a substantially constant and relatively high torque over a wide range of speeds. Such a high torque is particularly advantageous for motor-driven transfer movements of the friction-welding device from a rest position to a welding position and possibly back. If high torques can be provided with the strapping device, then it is possible to make the initiation of the transfer movements dependent on overcoming high forces. This increases the safety, in particular the functional safety, since the Friction welding device can not be moved unintentionally due to external influences from their respective intended position.

With the use of a brushless DC motor as drive for the clamping device, further advantages can be achieved. As a result, it is possible to control the clamping operation speed dependent. This allows, for example, even at low speeds a - compared to previously possible torques - to provide comparatively high torque of the clamping device. Thus, with such mobile strapping devices, for example, for the first time a band with low speed but still put around packaged goods with a high clamping force towards the end of the clamping process. In previous clamping devices to achieve a sufficient belt tension, the band had to be moved at the beginning of the tensioning process at high speed, so that towards the end of the clamping process in the band, the desired belt tension can be achieved. The tape is thereby whipped properly against the packaged goods, which involves a high risk of damage to the packaged goods in itself. This also sensitive packaged goods, now with significantly lower risk of damage with a band with high band tension can be strapped.

Furthermore, a speed-dependent or speed-controlled tensioning operation also enables a quick first tensioning, i. a tensioning at a high belt retraction speed, followed by a second tensioning operation with reduced belt retraction speed compared to the first tensioning operation. The belt retracting speeds can be adjusted in particular in such brushless motors due to the ability to adjust the speed of the motor shaft and the motor torque in certain areas independently, adjust the required or desired conditions in both clamping operations. With the described division into a first and at least a second clamping operation, particularly high belt tensions can be achieved.

According to a further aspect of the present invention, which may also have independent significance, the strapping device is provided with means by which rotational positions of the motor shaft or positions of components of the strapping device dependent on the motor shaft can be determined. The Information about one or more rotational positions may preferably be used by a control of the strapping device to control components of the strapping device, such as the friction-welding device and / or the tensioning device. If a brushless DC motor is used as the drive, this can be done in a particularly simple manner. Such motors must already for their commutation information about current positions of the rotating component of the engine, which is usually designed as a rotating armature determine. For this purpose, detectors or sensors, such as Hall sensors provided on the engine, the rotational positions of the rotating motor component, for example, the motor shaft or position of the motor shaft dependent position of an arranged in the drive train of the welding device element, determine and provide the engine control available. This information can be used with advantage also in particular for controlling the friction-welding device. The means or detectors for determining the rotational position may also be part of a circuit for controlling an electronically generated commutation of the electric drive. Thus, in a preferred embodiment of the strapping device can be provided that a number of revolutions of the rotating component of the engine is determined to make a switching operation when a predetermined value for the revolutions. This switching operation may in particular be a switching off of the friction-welding device to end the generation of a friction-welded connection. In a further advantageous embodiment of the invention it is provided that the engine can not be turned off at one or more specific rotational positions or can only be parked at one or more specific rotational positions.

Finally, it has proven to be advantageous if, for the transfer of the welding device from the rest position into the welding position and back, a device is provided which has a knee lever device. The lever of the toggle device connected to one another via a joint can be brought into its two end positions by overcoming two dead center positions, in which they hold the welding device in the rest position or in the welding position. Advantageously, the toggle device is at least in the two end positions held by a respective force, preferably by a force emitted by a mechanical spring force. The toggle device should only be able to get from one end position to the other by overcoming this force. With the toggle device can achieve the advantage that end positions of Welding device can only be changed by overcoming relatively high torques. Since this applies in particular to the welding position, the toggle device contributes to further increasing the functional reliability of the strapping device. Furthermore, the toggle device advantageously complements the drive train of the strapping device having a brushless DC motor and a planetary gear drive in an embodiment of the invention, in order to automatically transfer the welding device into its welding position, since all the components are capable of generating high torques respectively Only execute movements when high torque is present.

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;

Figure 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;

Figure 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 eirte 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 exemplary 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 discharged 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 planetary gears 37 about the motor shaft 27 results in a rotational movement of the output 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 thus 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 extending through the toggle lever 61 (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 the Cam 33 is 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 Reibschweissverbiridung 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 of the strapping device.

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 operating the switch 17, the actuator 16 can be occupied only with the function of 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 arm 9, the cam can perform a rotational movement of about 30 ° and move the rocker 8 or 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.

LIST OF REFERENCE NUMBERS

1

Strapping device 1

2

casing

3

Handle

4

baseplate

6

tensioning device

7

tensioning wheel

7a

peripheral surface

8th

seesaw

8a

Rocker pivot axis

9

rocker lever

10

friction welder

11

Schweissschüh

12

chipboard

12a

clamping surface

12b

contact area

13

transmission device

14

electric DC motor

15

accumulator

16

actuator

17

switch

18

actuator

19

Transfer device

20

rotor

HS1

Hall sensor

HS2

Hall sensor

HS3

Hall sensor

22

electronic control

24

stator

25

bridge circuit

27

motor-side output shaft

28

sun

30

wave

31

gear

32

cam

32a

area

33

cam

35

sun

36

freewheel

37

planet

38

ring gear

39

wave

40

output gear

42

freewheel

43

bevel gear

46

planetary gear

47

sun

48

planet

49

tensioning wheel

50

toothed belt

51

pinion

52

eccentric

53

welding shoe

54

eccentric shaft

55

eccentric

56

Welding shoe arm

57

Rotation axis eccentric shaft

60

Toggle lever device

61

longer toggle

62

swivel axis

63

pivoting element

64

contact element

65

swivel axis

66

swivel axis

67

compression spring

68

connecting line

69

swivel axis

70

Band-running direction

71

recess

72

bearing surface

73

screw

74

Long hole

Claims (15)

1. Mobile strapping apparatus for strapping packed articles by way of a strapping band, said apparatus having
   a tensioning device (6) for applying a band tension to a loop of a strapping band, and also a friction-welding device (10) for producing, by means of a friction-welding element, a friction-welded connection at two regions, located one above the other, of the loop in the strapping band, and
   a chargeable energy store for storing electrical energy, which is releasable as drive energy for motorized drive movements at least for the friction-welding device (10) for producing a friction-welded connection,
   characterized
   by a planetary gear mechanism for transmitting and for changing the rotational speed of a drive movement provided by an electric drive of the friction-welding device (10).
2. Mobile strapping apparatus according to Claim 1, characterized in that the electric drive is in the form of a brushless DC motor (14).
3. Mobile strapping apparatus according to at least one of the preceding claims, characterized by automatic disconnection of the electric drive.
4. Mobile strapping apparatus according to at least one of the preceding claims, characterized in that a duration of a welding cycle, during which the friction-welding device (10) is in use, is settable, it being possible to predetermine the duration depending on a number of revolutions of the electric drive.
5. Mobile strapping apparatus according to at least one of the preceding claims, characterized by means for transferring the friction-welding device (10) from a rest position into a welding position, wherein the means are drivable by the same drive with which an oscillating movement of a friction-welding element used for producing a friction weld can also be produced.
6. Mobile strapping apparatus according to at least one of the preceding claims, characterized in that the friction-welding device (10) is provided with a toggle lever (61) which is pivotable between two end positions, wherein one end position of the toggle lever (61) determines a friction-welding position and the other end position determines a rest position in which the friction-welding device (10) is not in use.
7. Mobile strapping apparatus according to Claim 6, characterized in that the toggle lever (61) is articulated in a pivotable manner about two pivot axes, wherein at least the movement in a direction between the two end positions takes place as a motor-driven movement driven by the electric drive of the strapping apparatus.
8. Mobile strapping apparatus according to Claim 6 or 7, characterized by the planetary gear mechanism, which transmits a drive movement of the electric drive to the tensioning device (6) in order to move the toggle lever from its rest position into the friction-welding position.
9. Mobile strapping apparatus according to at least one of Claims 6 and 7, characterized in that the toggle lever (61) is spring-loaded.
10. Mobile strapping apparatus according to at least one of the preceding claims, characterized by only a common electric drive for the tensioning device (6) and the friction-welding device (10).
11. Mobile strapping apparatus according to Claim 10, characterized in that the common electric drive drives preferably only the tensioning device (6) in one of its two directions of rotation and drives preferably only the friction-welding device (10) in the other direction of rotation.
12. Mobile strapping apparatus according to at least one of the preceding claims, characterized by a speed-controlled tensioning cycle of the tensioning device (6), during which the electric drive is operated at least temporarily at different rotational speeds with an at least substantially constant torque.
13. Mobile strapping apparatus according to at least one of the preceding claims, characterized by an actuating means for triggering an automatic friction-welding process, in which the friction-welding device (10) is transferred into a friction-welding position by a motorized drive movement and the friction-welded connection is produced by means of the friction-welding element.
14. Mobile strapping apparatus according to at least one of the preceding claims, characterized in that an output shaft on the motor side is operatively connectable to a plurality of functional components of the strapping apparatus, wherein one of the functional components is the friction-welding device (10), upstream of which the at least one planetary gear mechanism is connected.
15. Mobile strapping apparatus according to at least one of the preceding claims, characterized by two planetary gear mechanisms (46) for transmitting and for changing the rotational speed of a drive movement provided by an electric drive of the friction-welding device (10).

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