Abstract:
The invention relates to a device for feeding a quasi-endless material web ( 4 ) to a manipulation device ( 19 ) receiving the material web ( 4 ), wherein a feed tension unit ( 8 ) is provided, through which the material web ( 4 ) is fed in an S-shape. The feed tension unit ( 8 ) comprises a pivotal feed dancer roller ( 12 ), the angle positions thereof being captured by a feed angle sensor ( 34 ) and fed to a control unit ( 36 ), by means of which the material web ( 4 ) is fed or retracted by a dispenser roller motor ( 3 ) in the direction of the manipulation device ( 19 ), depending on the deviation of the angle position from a reference angle position. Substantially uniform tension in the material web ( 4 ) is thereby ensured, even under extreme operating conditions.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a U.S. National Phase patent application based on International Application Serial No. PCT/EP2010/002209 filed Apr. 9, 2010, the disclosure of which is hereby explicitly incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a device for feeding a quasi-endless material web. 
     2. Description of the Related Art 
     Devices for feeding a quasi-endless material web, such as according to DE 12 46 344 A, frequently have a pivoted dispenser roll and a feed tension unit which is equipped with a swivel-mounted floating roll. The swivel-mounted dispenser roll, held under tension by a helical tension spring, is used to give the material web a predetermined tensile stress by means of the helical tension spring. This approach had proven useful under operating conditions with a tensile load of the material web that does not fluctuate greatly. 
     SUMMARY OF THE INVENTION 
     The present invention provides a device for feeding a quasi-endless material web to a manipulation device receiving the material web, which operates very reliably even with very non-uniform tensile loads of the material web. 
     Even relatively strong changes in the tensile stress of the material web, caused by relatively quick, extensive movements of the manipulation device, for example, and the securing of the functionality of the device can be balanced quasi-instantaneously because in the device according to the invention the dispenser roll, controlled by the control unit, is triggered via the dispenser roll motor to add or remove material web to or from the manipulation device via the angle sensor detecting the angular position of the dispenser roll when certain angular peripheral positions of the floating roll are reached or exceeded and thus the change range of the tensile loads of the material web that can be buffered by the pivotable floating roll is left. 
     Based on the following explanation of an exemplary embodiment of the invention with reference to the figures of the drawing, further expedient embodiments and advantages are shown. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above mentioned and other features and objects of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of embodiments of the invention taken in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a side view of an exemplary embodiment of a device according to the invention; 
         FIG. 2  is a perspective view of an exemplary embodiment of a feed tension unit of the device according to the invention according to  FIG. 1 ; 
         FIG. 3  is a block diagram of an exemplary embodiment of a control unit for a device according to the invention; 
         FIG. 4  is a plan view of a swivel arm with a device according to  FIG. 1  that is supported in a slidable manner along rails; and 
         FIG. 5  is an enlarged representation compared to the representation according to  FIG. 4  of the swivel arm in the attachment region with a supporting frame. 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. Although the exemplifications set out herein illustrate embodiments of the invention, in several forms, the embodiments disclosed below are not intended to be exhaustive or to be construed as limiting the scope of the invention to the precise forms disclosed. 
     DETAILED DESCRIPTION 
       FIG. 1  shows an exemplary embodiment of a device according to the invention in a side view. The exemplary embodiment according to  FIG. 1  has a rigid, torsionally stiff supporting frame  1 , on which a dispenser roll  2  is rotatably supported. The dispenser roll  2  can be driven to rotate in two directions of rotation via a dispenser roll motor  3 . 
     On the dispenser roll  2  a quasi-endless material web  4  is stored, which in this exemplary embodiment is formed by two conveyor belts  5  arranged at a distance parallel to one another with mounting elements  6  attached at regular intervals between the conveyor belts  5 . 
     The material web  4  is fed in a conveyor direction after the dispenser roll  2  through a guide sleeve  7  to a feed tension unit  8  of the device according to the invention. The feed tension unit  8  in this exemplary embodiment has an inlet-side fixed feed roll  9  as a first fixed roll, which is attached rigidly and rotatably to an ascending support bar  11  facing away from the dispenser roll  2 . Furthermore, the feed tension unit  8  has a floating feed roll  12  as a floating roll, which is pivotable via a floating feed roll supporting arm  13  with respect to the inlet fixed roll supporting arm  10 . Furthermore, the feed tension unit  8  is equipped with an outlet-side fixed feed roll  14 , which on the side of the floating feed roll  12  facing away from the inlet-side fixed feed roll  9  as a second fixed roll is connected via an inlet fixed roll supporting arm  15  to the support bar  11  in a rigid and rotatable manner. 
     It is discernible from  FIG. 1  that the material web  4 , after passing through the guide sleeve  7 , is placed in an S-shaped manner around the inlet-side fixed feed roll  9 , the floating feed roll  12  and the outlet-side fixed feed roll  14 . 
     Furthermore, the exemplary embodiment of a device according to the invention according to  FIG. 1  has a swivel arm  16  projecting from the supporting frame  1  and, with arrangement of the device as directed, aligned horizontally, which via a rocker pivot  17  with use as directed can be pivoted in the horizontal with respect to the supporting frame  1 . On the end of the swivel arm  16  facing away in front of the supporting frame  1 , a rotatable feed deflection roll  18  is attached, via which the material web  4  can be fed to a manipulation device  19 . 
     With the manipulation device  19 , which in this exemplary embodiment is embodied in the form of a setting gun for the mounting elements  6 , the mounting elements  6  can be mounted by a worker  20 , for example, on a motor vehicle not shown in  FIG. 1 . After the assembly operation, the material web  4  is released from the mounting elements  6  and has only the two conveyor belts  5 , which emerge from the manipulation device  19 . 
     This part of the material web  4  passes through a further guide sleeve  21 , which is attached to the end of the swivel arm  16  facing away from the supporting frame  1  and wraps around a further discharge deflection roll  22 , via which the material web  4  can be fed to the supporting frame  1  again. 
     On the end of the support bar  11  facing towards the swivel arm  16 , an inlet-side fixed discharge roll  23  is fed as a first fixed roll of a discharge tension unit  24 . The discharge tension unit  24  is furthermore equipped with a floating discharge roll  25  as a floating roll, which is arranged rotably via a floating discharge roll supporting arm  26  and pivotally with regard to a fixed discharge roll supporting arm  27  rigidly connected to the support bar  11 . On the fixed discharge roll supporting arm  27  furthermore an outlet-side fixed discharge roll  28  is rotatably attached as a second fixed roll of the discharge tension unit  24 . 
     It is discernible from  FIG. 1  that the material web  4  in the form of the two conveyor belts  5 , after emerging from the manipulation device  19 , is placed in an S-shaped manner around the inlet-side fixed discharge roll  23 , around the floating discharge roll  25  and around the outlet-side fixed discharge roll  28  and via a rotatable auxiliary roll  29 , fixedly attached to the supporting frame  1 , of a further guide sleeve  30  as well as by a routing unit  31  set up for the space-saving routing of the material web  4  discharged from the manipulation unit  19  by lateral to and fro guidance of the material web  4 , is fed to a receiving roll  32  of the exemplary embodiment of the device according to the invention. The receiving roll  32  can be driven to rotate in both directions of rotation via a receiving roll motor  33  according to the dispenser roll  2 . 
       FIG. 2  shows in a perspective view the inlet-side fixed feed roll  9  and the floating feed roll  12  of the feed tension unit  8  with the material web  4  fed through in an S-shaped manner. From  FIG. 2  it is discernible that the floating feed roll supporting arm  13  is supported pivotably in the inlet fixed roll supporting arm  10 , so that during the pivoting of the floating feed roll  12 , the S-shaped wrapping of the inlet-side fixed feed roll  9  and the floating feed roll  12  is more or less marked, to equalize certain changes in the tensile stress exerted on the material web  4  with the gravitational force acting on the floating feed roll  12  as a restoring force. 
     Alternatively or additionally to the gravitational force, with a modification (not shown) of the exemplary embodiment explained it is provided that the or a further restoring force is exerted by a torsion spring acting on the floating feed roll supporting arm  13 . 
     The feed tension unit  8  is furthermore equipped with a feed angle sensor  34  as an angle sensor, with which control signals assigned to the angular positions of the floating feed roll supporting arm  13  can be generated. 
     Furthermore, it is discernible from  FIG. 2  that the inlet-side fixed feed roll  9  is coupled with a direction of rotation sensor  35 , the output signals of which are assigned to the respective direction of rotation of the inlet-side fixed feed roll  9 . 
       FIG. 3  shows in a block diagram an exemplary embodiment of a control unit  36  of a device according to the invention. The control unit  36  is in connection on the input side with the feed angle sensor  34  and the direction of rotation sensor  35 . The output signals of the feed angle sensor  34  can be fed to an angle evaluation module  37 , with which the current angular position of the floating feed roll supporting arm  13  can be converted into an input signal for a rotational control module  38 . 
     With the rotational control module  38  of the control unit  36  a frequency converter  39  arranged upstream of the dispenser roll motor  3  can be controlled, in order when a reference angular position of the floating feed roll supporting arm  13  is exceeded as a first form of the deviation from a reference angular position to trigger an addition of material web  4  via the performance of a feed rotation of the dispenser roll  2  and/or when the same or a further reference angular position is fallen below as a second form of deviation from a reference angular position to trigger the dispenser roll motor  3  to rotate the dispenser roll  2  in a return direction opposite to the feed rotation to return material web  4  onto the dispenser roll  2 . 
     In this manner it is ensured that in the event of deviation of the floating feed roll supporting arm  13  from the or a reference angular position by active feed or by active discharge the material web  4  is loaded within predetermined limits with an essentially constant tensile stress in order to guarantee a reliable use of the manipulation device  19  for example even in the case of rapid extensive movements. 
     It is further discernible from  FIG. 3  that the direction of rotation sensor  35  is connected to a first direction of rotation discrimination module  40  and the frequency converter  39  to a second direction of rotation discrimination module  41 . The direction of rotation discrimination modules  40 ,  41  are attached to an AND operator element  42 , which then supplies an output signal for an error display module  43  and a STOP signal fed to the frequency converted  39  to switch off the control when the directions of rotation of the dispenser roll  2  and the inlet-side fixed feed roll  9  are contrarotating, which is indicative of an incorrect operation of the device according to the invention. 
     The control unit  36  furthermore has a counter module  44  connected to the manipulation unit  19 , with which counter module the mounting elements  6  separated by the manipulation unit  19  from the conveyor belts  5  can be counted. The counter module  44  is connected to a parameter set selection module  45 , which in turn is connected to the frequency converter  39 . Depending on the counter reading stored in the counter module  44 , the rotational speed of the dispenser roll  2  can be preset in at least two stages in order to take into account the decreasing level of the dispenser roll  2  with an effective discharge of the material web  4  from the dispenser roll  2  averaged over a longer period such that the dispenser roll  2  rotates relatively slowly with a still relatively high level and rotates more quickly with a relatively low level compared to a relatively high level. 
     In a further development of the device according to the invention explained above, it is provided that the discharge tension unit  24  is also equipped with a discharge angle sensor corresponding to the feed angle sensor  34  with respect to functionality and with a discharge direction of rotation sensor corresponding to the feed angle sensor  24  with regard to functionality for the outlet-side fixed discharge roll  28 , which with the duplication of the elements of the control unit  36  explained above, lead to a corresponding control of the direction of rotation and the speed of the receiving roll  32 , if the floating delivery roll supporting arm  36  deviates from the or a reference angular position. 
       FIG. 4  shows in a plan view the swivel arm  16  of the exemplary embodiment according to  FIG. 1 . It is discernible from  FIG. 4  that a first manipulation device suspension  46  and a second manipulation device suspension  47  are attached to the swivel arm  16  in order, in addition to the manipulation device  19  shown in  FIG. 1 , to have a further manipulation device  19  by way of replacement and, as needed, to be able to store both manipulation devices  19  at a predetermined location in the event that they are not used. The representation according to  FIG. 4  shows that the device according to the invention is supported on guide rails  48  so as to be slidable to and fro along a working stroke, in order to be able to use the material web  4 , for example, in an assembly line at different locations. 
     As can be seen from  FIG. 4 , at the end of the swivel arm  16  facing towards the supporting frame  1 , a lateral position detection unit  49  is arranged, which is explained in more detail below. 
       FIG. 5  shows the lateral position detection unit  49  in an enlarged plan view compared to the representation in  FIG. 4 . The lateral position detection unit  49  has brackets  50  attached on both sides of the swivel arm  16  to the supporting frame  1 , on the ends of which facing away from the supporting frame  1  in each case a lateral stop damper  51  and an induction sensor  52  are attached. Furthermore, the ends of the bracket  50  facing away from the supporting frame  1  are mechanically connected via respectively one helical tension spring  53  to the supporting arm  16 , which hold the supporting arm  16  essentially in a central position without exerting laterally acting forces. 
     When the swivel arm  16  approaches one of the induction sensors  52 , however, from when a predetermined distance threshold value is fallen below, the respective induction sensor  52  emits an output signal to a control unit, not shown in  FIG. 5 , which causes the device according to the invention to be moved in the direction of the inductions sensor  52  emitting the output signal until the distance threshold value is again exceeded. The device according to the invention can thus be automatically moved very comfortably by a worker  20  over a working stroke stipulated by the length of the guide rails  48 . 
     While this invention has been described as having a preferred design, the present invention can be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and which fall within the limits of the appended claims.