Feeding and tensioning device for a strap to be tensioned around a package.

The invention relates to a feed and clamping device for a around a package to exciting strapping that the first can be advanced with, the strap frictionally receiving between them pair of wheels in a the to be strapped package by far encircling band guide and then at article held the front end of the tape by a rotation direction reversal wheels^pAares then with a special tensioning wheel with a lower feed rate and greater force can be tensioned by retracting into abutment against the package brought and.

In this device, the pair of wheels is driven for advancing and retracting the tape andthe tension wheel by a single motor, but between the pair of wheels for feeding and retracting the strap, and the tensioning wheel, a reduction gear is provided so that the tensioning wheel with a smaller speed and greater force rotates. The tensioning wheel is partly wrapped around by the strap so that the tension wheel frictionally engages when tensioning the belt. The tensioning wheel is associated with a tape guide, so that when the strap feeding the tape only bears against the inside of the tape guide and does not come against the tension wheel to the plant. Upon retraction of the belt of the tensioning wheel wraps around part of the strap against the tensioning wheel comes to rest and is frictionally entrained by this, so that the actual tightening occurs. To tighten the strap so the strap is brought by the count-down, for advancing serving pair of wheels against the tensioning wheel in contact with the immediately entire pressing force for the frictional engagement comes into effect. Upon further tightening this pressing force can not increase, so that only a limited tightening is possible with the tensioning wheel.

The invention has for its object to provide a feed and clamping device of the type explained in which such disadvantages are avoided and the advance, retract and tension of the strap can be easily performed and during tensioning of the strap the drivable tensioning wheel with correspondingly the growing tension in the strapping increasing contact pressure against the strap rests without permanently deforming the existing particular plastic strap during tensioning.

This object is inventively achieved in that tensioning of the strapping carried out with a pair of wheels, one of which is a wheel designed as a co-running wheel and mounted the other wheel with an associated engine in tightening direction and with its axis in a pivoting lever such that when tensioning the strapping and the drivable by strapping partially looped tensioning wheel against which supporting against the nitlaufende wheel strap with in accordance with the growing tension rests in strapping increasing Nnpreßkraft. Thereby, a clamping device is easily created with a very high voltage in the strapping is achievable because during tensioning of the strap slipping of the strap is not to be feared on the tensioning wheel, as the drivable tensioning wheel with in accordance with the growing tension in the strapping increasing contact pressure is pressed against the supporting himself against the idler wheel strap.

In order to avoid crushing and deforming the in particular made of plastic strapping, the direction of rotation of the driven tensioning wheel runs in such a way that a force component occurs in terms of discrepancy pushing of the two wheels, but which force component is less than that caused by the swing lever by the belt tension pressing force. By the pivotable mounting of the tensioning wheel on the pivot lever and the direction of rotation of the tensioning wheel is thus achieved in a simple way that the resultant of the direction of rotation of the tensioning wheel force component which caused the swing lever by the belt tension pressing force is opposed, so that these two forces not add to such a force and cause destruction or deformation of the particular made of plastic strapping. The resultant of the direction of rotation of the tensioning wheel force component can be very small, since it. For the gentle treatment of, in particular made of plastic, strapping already sufficient if the contact pressure is not increased by the direction of rotation of the tensioning wheel

The drivable tensioning wheel can od on the metallic shell surface with the friction enhancing knurling. Like. Be provided. In this way slipping of the strapping band is prevented on the outer surface of the drivable tensioning wheel in a simple manner.

The coming against the strap to bear lateral surface of the idler wheel may be formed of an abrasion resistant, soft elastic pad. When tensioning the strapping the drivable tensioning wheel is pressed to the strap in the abrasion-resistant, soft elastic pad idler wheel a, so that a large contact area is achieved on both the drivable tensioning wheel and during idler wheel, at the same time easily damage, particularly from plastic existing strapping be avoided.

The drivable tensioning wheel can also form a guide for the strap and extend the drivable tensioning wheel from the package leading part of the strap at least approximately parallel to the pressing direction of the mounted on the pivot lever, drivable tensioning wheel. This is pressed in a simple manner by increasing the strap tension the drivable tensioning wheel with increasing contact pressure against which supporting against the idler wheel strap.

The pressing of the mounted on the pivot lever, drivable tensioning wheel against the supported by the idler wheel strapping can be carried out against the action of a force acting on the pivot lever spring. This is achieved in a simple manner that the pivoting lever mounted, drivable tensioning wheel is eager to assume a position in which the contact pressure is low or zero.

The bearings on the pivot lever, drivable tensioning wheel can before tensioning, during the advance of the strap, be held with the spring in a basic position, in which the drivable tensioning wheel and the zugehörige'mitlaufende wheel on the free feeding of the strap with a thickness of the strap-border distance are arranged to each other. The strap can thus be passed freely when advancing between the drivable tensioning wheel and the associated idler wheel.

The carrying the drivable tensioning wheel swivel lever can rest in its normal position with an adjustable stop against a fixed stop surface. Thus, the thickness of the strap-border distance between the drivable tensioning wheel and the idler wheel can be adapted to the particular requirements of the free feeding of the strap in a simple manner.

That the strap frictionally therebetween receiving pair of wheels for advancing and retracting the strap may be formed of a in both directions with its own motor driven projection and Zurückziehrad and an idler wheel. Thus, the pair of wheels for advancing and retracting the strap of a drivable projection and Zurückziehrad and a follower wheel is formed in an advantageous manner, the projection and Zurückziehrad has its own motor, which can be effective in both directions of rotation. When turning in one direction of rotation, the feeding the tape and in the other rotational direction is the retraction of the strapping.

The cooperating with the driven projection and Zurückziehrad idler wheel can also form the revolving wheel of the drivable tensioning wheel. The idler wheel thus acts together in a simple manner with the driven projection and Zurückziehrad and the drivable tensioning wheel.

The driven projection and Zurückziehrad may comprise a polished metal casing surface. The driven projection and Zurückziehrad thus has a low coefficient of friction, so that only small projection and retraction forces can be transmitted to the driven projection and Zurückziehrad. This force is sufficient to engage the feed the strapping which to umreifende.Packstück spaced encircling band guide. Further, this small force is sufficient when switching the motor to withdraw the tape when held fixed front end of the tape, so that the strap comes into abutment against the package and against the tensioning wheel. Furthermore, this force is sufficient to bring the mounted on the pivot lever drivable tensioning wheel into engagement with the strap, the case bears against the idler wheel. Further retraction of the band, ie, the tensioning of the belt will now be made of the drivable tensioning wheel, wherein the driven projection and Zurückziehrad slips on the strapping band.

The idler wheel may be on the rotatably mounted an arm of a rocker and the rocker engage a spring under the action of the rocker is held in a normal position, in which the idler wheel frictionally abuts against the at drivable projection and Zurückziehrad supporting strap , By acting on the rocker spring thus rotatably supporting the idler wheel rocker is held in the basic position, in which the idler wheel frictionally against which the driven projection and Zurückziehrad rests supporting strap.

The carrying the drivable tensioning wheel swivel lever and supporting the idler wheel rocker can be pivoted on a common pivot pin. Characterized both the pivot lever carrying the drivable tensioning wheel and the rocker carrying the follower wheel on a single bearing pin is mounted pivotably in a simple manner.

The bearing on the rocker, idler wheel may be convertible during tensioning of the strap through the coming of the drivable tensioning wheel and acting on the idler wheel contact pressure against the action of the spring into a release position in which the drivable Vorschieb and Zurückziehrad and the associated idler wheel the free tensioning of the strap with a thickness of the strapping border are spaced to each other. This is achieved in an advantageous manner that the effect of the S^pannrades the idler wheel of the driven projection and Zurückziehrad is released so that the drivable Vorschieb and Zurückziehrad no longer slips on the strap and thus damage of the strap can be avoided.

The rocker can be assigned to limit the pivoting movement into the release position a stop. This too wide a pivoting of the rocker is avoided on the release position into a simple manner.

The rocker karn an actuated upon reaching the release position switch with time relay for switching off the engine to be assigned by the tensioning wheel. Upon reaching the release position thereby actuating the rocker switch with a time relay, which switches off the engine for the tensioning wheel. The time relay can be adjustable in a simple manner, so that after pressing the switch for a predetermined time elapses until the motor of the tensioning wheel is turned off. This period thus determines the magnitude of the voltage, which is caused in the strapping. The greater the period of time is, the greater the tension in the strapping.

The rocker may also be a more resilient in the pivoting direction and - be associated with provided with an adjustable biasing force store and operable on reaching the release position switch for switching off the engine from the tensioning wheel. Thereby an accurate adjustment of the tension in the strap is easily achieved, since before reaching the release position, the pivoting movement of the rocker must be carried out against the action of an energy accumulator, the force of which is adjustable. Reaching the release position is thus dependent on the tension in the strap so that the actuation of the switch to turn off the engine from the tensioning wheel is carried out only with the achievement of the desired tension in the strap.

The duty of the rocker in pivoting direction motor memory can be formed by a helical compression spring is supported at one end to the passing against an abutting against a stop and with the rocker in Wirkverbundung piston and at the other end against an adjustable in the direction of loading slide. The forming the energy storing coil spring can thus easily adjusted to the desired preload and thus the tension in the strap to be brought to the desired size.

The against the compression coil spring fitting, adjustable slide can have on its, the compression coil spring side facing away, a wedge surface of a sphere, the plant, which on the wedge surface of the slider is provided with a threaded spindle transversely to the loading direction of the helical compression spring adjustable. can with the transverse to the loading direction of the helical compression spring threaded spindle Thus, the ball can be adjusted on the wedge surface of the slide and thus in a simple and reliable way, the desired bias voltage can be applied to the helical compression spring.

In the drawing the invention is shown in one embodiment, and show namely:<ul><li>FIG. 1 and the feed and clamping device of the invention for a package to be clamped strapping in a schematic view in the feeding position</li><li>Fig. 2, the feed and clamping device in the clamping position.</li></ul>

The feed and clamping device for a to a not-shown package to exciting strapping 10 illustrated in the drawing has a the strap 10 force fit therebetween receiving pair of wheels 11, 12, enclosing with the strap 10 in a the to be strapped package by far , tape guide, not shown can be advanced. By a rotation direction reversal of the pair of wheels 11, 12, the strap can then be brought by retracting into abutment against the package when held fixed front end of the tape. After application of the strapping. band 10 may be 10 provided with the required voltage to the package then with a special, driven tensioning wheel for themselves the strap.

D as tensioning of the strapping band 10 is accomplished with a pair of wheels 12, 13, of which the one wheel 12 is formed as a co-running wheel and the wheel 13 is rotatably connected to a not shown motor in the tensioning direction. The tensioning wheel 13 is supported so with its axis 14 in a pivoting lever 15 that during tensioning of the strap 10 the drivable tensioning wheel 13 abuts against which supporting against the idler wheel 12 strap 10 according to the increasing tension in the strap 10 increasing contact pressure. To this end, the drivable tensioning wheel 13 also forms a deflection for the strapping 10, said from the drivable tensioning wheel 13 for the package leading part of the strap 10 extends at least approximately parallel to the pressing direction of the swing lever 15 mounted, drivable tensioning wheel. 13 In a simple way is thus achieved that match the growing tension in the strapping increasing Anpreßkraftdas tensioning wheel 13 is pressed against the up supporting against the idler wheel 12 strap 10 so that no risk of slipping of the tensioning wheel 13 on the strap and on the rising tension is.

By crushing and deforming the, in particular consisting of plastic, to prevent the strapping band 10, the direction of rotation of the driven tensioning wheel 13 runs in such a way that a force component in terms of discrepancy pushing of the two wheels 12, 13 occurs, but this force component is less than that of the pivoting lever 15 caused by the belt tension pressing force is. Characterized one of the destroying and deforming, in particular made of plastic, the strapping band is prevented in a simple manner. Here, the force component can be very small since it mainly as a way that evoked by pivoting lever 15 by the belt tension pressing force is not increased by the caused by the direction of rotation of the tensioning wheel 13 force component.

In order to achieve an anti-slip system of the tensioning wheel 13 against the strap 10, the drivable tensioning wheel 13 is in its metallic. Lateral surface 16 or the like with a not illustrated, increasing the coefficient of friction, knurling. provided. Furthermore, the coming against the strap 10 to the plant generated surface 17 of the idler wheel 12 is formed of an abrasion resistant, soft elastic pad 18th When pressing the tensioning wheel 13 against the supported by the idler wheel 12 strapping the tensioning wheel 13 is expressed with the overlying strap 10 in the abrasion-resistant, soft elastic pad 18, so that a large surface conditioning of the strap 10 at both the idler wheel 12 and the idler wheel 13 takes place. Damage, in particular consisting of plastics material, the strapping band 10 is thus avoided in a simple manner.

The pressing of the pivot lever 15 mounted, drivable tensioning wheel 13 takes place against the supported by the idler wheel 12 strapping 10 against the action of a force acting on the pivot lever 15 spring 19. The spring 19 is designed as a coil spring and one end with a hook 20 at the free end of the pivot lever 15 and at the other end supported by a hook 21 on a stationary stop face 22nd The force of the spring 19 of the pivot lever 15 and thus the tensioning wheel 13 is committed to maintaining a basic position in which the drivable tensioning wheel 13 and the associated idler wheel 12 arranged on the free feeding of the strap 10 with the thickness of the strapping 10-border distance apart are. In the basic position of the drivable tensioning wheel 13 bearing pivot lever 15 is equipped with an adjustable stop 23 against the fixed stop surface 22nd The adjustable stop 23 is in this case of a screw 24 with locknut 25 gebildet.In the basic position is the screw 24 with its head against the fixed stop surface 22 and can be adjusted according to the prevailing circumstances.

The on the pivot lever 15 mounted, drivable tensioning wheel 13 takes the basic position before tightening, a while advancing the strap 10th As already explained, for advancing and retracting the strap 10 a the strap 10 is provided kräftschlüssig therebetween receiving pair of wheels 11, 12th This pair of wheels 11, 12 is formed by a drivable in both directions of rotation with a private, non-illustrated engine projection and Zurückziehrad 11 and the same time cooperating with the tensioning wheel 13 idler wheel 12th

The idler wheel 12 is rotatably mounted on the one arm 26 of a rocker 27, on which a helical compression spring 29 engages, under the action of the rocker is held in a normal position 27 in which the idler wheel 12 positively against which the drivable Vorschieb- and Zurückziehrad 11 supporting strap 10 applies. The idler wheel 12 is thus urged by the spring-loaded rocker 27 against the projection and Zurückziehrad 11 so that the strap 10 is clamped non-positively between the wheels. 11 and 12 The driven projection and Zurückziehrad 11 has a polished metallic shell surface 30 so that between the projection and Zurückziehrad 11 and the strap 10 has only a slight friction occurs. The power transmitted to the strap 10 force is sufficient, however, to feed the band in which the material to be strapped package by far encircling band guide. Similarly, the force is sufficient to bring the strap 10 when held fixed front end of the tape by a rotation direction reversal of advancing and retracting wheel 11 by pulling back into abutment against the package.

The the drivable tensioning wheel 13 bearing pivot lever 15 and the pivotally mounted the idler wheel 12 bearing rocker 27 are on a common bearing journals 31st Thus only a single bearing pin 31 is used for the two pivotable parts 15 and 27th

The mounted on the rocker idler wheel 12 is, as illustrated particularly in FIG. 2 seen converted by the coming from the drivable tensioning wheel 13 and acting on the idler wheel 12 contact pressure against the action of the spring 29 into a release position during the tensioning of the strapping band, in of 12 10 border are spaced to each other, the driven projection and Zurückziehrad 11 and the associated idler wheel for free tensioning of the strap 10 with the thickness of the strap. Characterized the tensioning of the strapping band is not affected by the Vorschieb and Zurückziehrad 11 in a simple manner.

The rocker 27 is assigned for limiting the pivotal movement into the release position a cooperating with the first pivot arm 26 Anschlag'32. Characterized too wide a pivoting of the rocker is prevented 27 through the release position also in a simple manner.

The stop 32 is a switch 33 associated with an adjustable time relay, not shown, with the engine not shown in detail the tension wheel 13 is switched off.

When the intended use of the device, the strap 10 is first the strap 10 is advanced with the force-receiving between them-wheel pair 11, 12 in which the material to be strapped package by far encircling band guide. Here, the device assumes the basic position shown in FIG. 1, in which the idler wheel 12 is positively pressed to the federbelasteteten rocker 27 against which supporting against the projection and Zurückziehrad 11 strapping 10th Between the idler wheel 12 and the tensioning wheel 13, a distance is provided so that the strap can be pushed freely between the two wheels 12 and 13. FIG. Since the strap 10, the idler wheel 12 and the tensioning wheel 13 loops around the idler wheel a tape guide 37 and the tensioning wheel 12 is 13 associated with a gang leader 38th The two gang leaders 37 and 38 are supported on the rocker 27th During advancement of the strap only the projection and Zurückziehrad 11 is driven in the feed direction while the tensioning wheel 13 remains without drive.

After the strap 10 is fully in the the to be strapped package by far encircling band guide is pushed forward, the strap is retracted so that the strap 10 applies under the same time holding the front end of the strap against the package. The retraction of the strap 10 will be within the projection and Zurückziehrad 11, for which the associated drive motor is driven in the direction of rotation entgegegengesetzten. By switching on the motor for the feed and Zurückziehrad 11 in the retracting direction and the motor for the tension wheel 13 is simultaneously switched, so that the tension wheel 13 rotates in the clamping direction. The turning of the tensioning wheel 13 with its own engine is carried out with a lower rotational speed and greater force.

Upon retraction of the strapping 1o after the application of the package is an increase in the tension in the strap. This makes the mounted on the pivot lever 15 tensioning wheel 13 is transferred against the action of the spring 19 from the basic position into the operative position in which the tension wheel 13 first comes against the strap 10 and the strap 10 against the idler wheel 12 to the plant. Further retraction of the strap "10, ie the tensioning of the strap 10 is carried out, now with the tension wheel 13. Initially is still the projection and Zurückziehrad 11 with the strap 10 in system. Through the contact pressure of the tensioning wheel 13 against the idler wheel 12 However, the rocker against the action of the spring 29 from the basic position transferred to the release position 27th transferring the rocker 27 with the idler wheel 12 against the action of the spring 29 from the basic position into the release position is effected as a function of the strapping 10 increasing voltage, and thus increasing pressure force with which the tension wheel 13 is pressed against the idler wheel 12th Uber When guiding the rocker 27 in the

Feigabestellung the switch is operated with the adjustable time relay for switching off the motor from the tensioning wheel fourteenth Depending on the setting of the time relay is the elimination of the motor from the tensioning wheel 13 immediately or after a predetermined period of time, so that can be set exactly how long the tensioning wheel 13 to continue to operate and increases the tension in the strap. By switching off the engine for the tensioning wheel 13 course takes place at the same time an engine stop of the projection and Zurückziehrad 11th

The adjustment of the tension in the strap with adjustable time relay is connected to the operator with difficulties since the values ​​have to be collected by experience. When changing the wrap length of the strap and packages of other material other periods must be rehired. To avoid this, the elimination of the motor in dependence on the respectively currently prevailing in the belt band voltage can be effected. To this end, the rocker arm is the second 28 27 a associated in the pivoting direction resilient and provided with an adjustable bias force storage 34th Transferring the rocker 27 into the release position thus takes place counter to the action of a bias provided with an adjustable energy accumulator 34 so that only the force of the energy accumulator 34 has to be overcome before the switch 33 is actuated. The switch 33 operates in this case without a time relay. The duty of the rocker 27 in the pivoting direction force accumulator 34 is formed by a helical compression spring which is supported at one end passing against an abutting against a stop 36 and the rocker 27 in Wirkverbundung Yolben 35 and at the other end against an adjustable in loading direction

Slide 39 is supported. The piston 35, the compression coil spring 34 and slider 39 are slidably disposed in a housing 40 which is supported on the stop wall 22nd The stop 36 of the piston 35 is formed by a spring ring which is inserted in a non-descript annular groove of the cylindrical casing 40th The piston 35 protrudes with a remote extension 41 from the housing 40 and engages with the second arm 28 of the rocker 27 is operatively connected to 27 brake the pivoting movement of the rocker in the release position, depending on the currently prevailing in strapping tape tension.

The against the coil compression spring 34 abutting, adjustable slide 39 has, on its the compression coil spring 34 side facing away from a wedge surface 42 for a ball 43, the system transversely to the loading direction of the helical compression spring 34 on the wedge surface 42 of the slide 39 is adjustable with a threaded spindle 44th can with the threaded spindle 44. Thus, the ball 43 can be adjusted on the wedge surface 42 of the slider 39, whereby a displacement of the slide is caused 39th Due to the displacement of the slider 39, the bias of the helical compression spring 34 is changed and thus change the force 27 opposes the pivoting of the rocker in the release position. The pivoting of the rocker 27 thus takes place in dependence on the pressure prevailing in the strapping band tension against the action of the force - memory 34, so that an accurate adjustment of the belt tension is possible to cause the switch 33 for switching off the motor from the tensioning wheel. 13

After reaching the predetermined voltage in the looped around the package strapping 10 now the overlapping band ends can be interconnected and the surplus for the strapping of the package part of the strap are separated. The required equipment may have a known structure and are therefore not mentioned here. After cutting off the excess for the strapping of the package part of the strap may now again be fed the strap.

As mentioned above, the illustrated embodiment is merely an example implementation of the invention and these are not limited thereto. Rather, many other embodiments and other applications are possible.

LIST OF REFERENCE NUMBERS

<ul><li>10 strapping</li><li>11 projection and Zurückziehrad</li><li>12 co-running wheel</li><li>13 tensioning wheel</li><li>14 axis of 13</li><li>15 pivot lever</li><li>16 lateral surface of 13</li><li>17 lateral surface of 12</li><li>18 edition of 12</li><li>19 spring at 15</li><li>20 hooks</li><li>21 hooks</li><li>22 stop surface</li><li>23 adjustable stop</li><li>24 screw</li><li>25 locknut</li><li>26 first pivot arm</li><li>27 rocker</li><li>28 second pan</li><li>29 spring</li><li>30 lateral surface of 11</li><li>31 journals</li><li>32 stop</li><li>33 switch</li><li>34 power storage</li><li>35 piston</li><li>36 stop for 35</li><li>37 gang leader to 12</li><li>38. Ringleader at 13</li><li>39 slide</li><li>40 housing</li><li>41 stepped approach 35</li><li>42 wedge surface</li><li>43 ball</li><li>44 threaded spindle</li></ul>