Patent Publication Number: US-2010116862-A1

Title: Manual unrolling device

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a device for unrolling and tearing off a rolled up foil or paper web, with a housing in which the winding body can be placed and which exhibits at least one foil outlet opening, and with at least one lid cover connected to the housing via a hinge and with at least one cutting element for separating a foil section. 
     Such a manual unrolling device is known from DE 203 15 295 U1. This device can indeed be used to tear off foil pieces creating a straight separation line. However, the separation is carried out such that the foil is drawn against a toothed bar, which requires a relatively great force. In addition, to withdraw the next section of the foil, the lid cover needs to be opened in order to grasp the foil again at its end and pull it out of the housing. 
     SUMMARY OF THE INVENTION 
     It is, therefore, the objective of the invention to optimize a manual unrolling device with regard to easier operation. 
     This objective is achieved by a manual unrolling device of the type described above and in accordance with the invention wherein:
         (a) the cutting element is arranged at the bottom side of the lid cover that points toward the foil outlet opening, and   (b) a redirecting bar and at least two pull-off bars, which serve as a guide for the foil, are arranged parallel to each other at the foil outlet opening. The upper edges of at least one of the pull-off bars are provided with a friction-enhancing coating, and a gap is formed between the pull-off bars in which the cutting element dips when the lid cover is closed.       

     The web, which may be a foil or thin paper, is initially unrolled slightly and guided to the outside of the housing such that the web runs beyond the pull-off bars. At the moment that the lid cover is closed, the web is pulled down by the outer redirecting bar such that it is guided downward adjacent to the housing and in this manner is tightened across the pull-off bars. 
     An alternative embodiment of the invention functions in the same manner. In this embodiment, however, the arrangement of the pull-off bars and of the cutting element in the housing and the lid are reversed, as compared to the first embodiment. 
     In this context, it is particularly advantageous to provide a symmetrical arrangement, wherein not only is a redirecting bar provided on the outside in front of the pull-off bars but also an additional inside redirecting bar is provided such that the web is pulled taut on both sides of the pull-off bars. 
     When closing the lid cover, the cutting element impacts the taut web such that it is separated at least across a significant portion of the width. 
     A discontinuation is provided preferably in the middle at the outer pull-off bar, which means, there is no bar at this location or the bar is significantly lower in height at this location such that the web cannot rest there. Thus, at this location it is in part not tightened as in the remaining areas, which results in it being not fully separated by the cutting element. Thus, a small bridge connection remains. 
     The user can grab the cut section and tear it off at the remaining bridge connection. To this end, he pulls at the same time additional portions of the foil web partially out of the manual unrolling device. The tip protruding in this manner from the manual unrolling device is used to easily grip the foil web upon the next use. 
     The hinges can be designed as film hinges such that the housing and lid cover can be made of one piece. To retain the foil or paper roll in the inside of the housing, an advantageous embodiment has a pivoting side flap attached on each side of the front side. This pivoting side flap has at least one holding mandrel for inserting it into a hollow cylindrical winding body of the web. The roll is supported by the holding mandrel and, because of this, will not drop out even when the lid cover is opened widely. 
     To this end, the housing can exhibit a slot-shaped recess on the front side and a holding mandrel designed as a flat bar can pivot into said recess. This allows even for the use of rolls that exhibit no or only a very tight hollow space. In this case, the side flaps simply remain on the outside in the up position. 
     The holding mandrel can engage in the slot-shaped recess by means of latching elements, for example in the form of partial elevations at the side areas. 
     Preferably, this side flap is connected to the housing or the lid cover via a film hinge. In particular, the film hinge is designed as a so-called butterfly hinge, such as is known, for example, from one-piece lid connections on packages for body care products. This design allows for defined closing and opening positions. Random unintentional opening of the side flaps is prevented because force must be used to overcome a dead center between these positions. According to one preferred embodiment, it is provided that when closing the lid cover at least one spring element, which is designed in particular as a leaf spring, is deflected. The spring element should preferably be arranged centrally in the area of the redirecting and pull-off edges. This has the following two effects: 
     Operation is made easier due to the slight counter-pressure because the lid cover is initially in the up position. 
     The spring, which not only pushes the lid cover up but in addition also pushes from underneath against the web located above, lifts it up from the pull-off bars. In this manner, the user can easily pull the web out to the desired length without having to hold the lid cover and having to keep the foil from the friction-reduced coated pull-off bars. 
     The other effect is that the user must overcome a certain counter force when closing the lid cover. As is also the case with precision mechanics pliers, where the pliers legs are spread apart of each other, this allows for sensitive force metering. In addition, the preset counter holding force when closing the lid cover also achieves a certain acceleration. In this manner, the cutting element exerts an impulse on the taut foil web underneath it. The sharpness of the cutting element combined with the sudden movement provides for easy separation of the web. 
     According to the invention, the separation is less caused by a strenuous indentation of a cutting element into the web but rather through a brief, fast, sudden closing movement of the lid cover. 
     In addition to or in place of the central spring element, spring elements can also be arranged in the housing on both sides in the front, in order to avoid canting even with an asymmetrical handling and to achieve the desired result. 
     For a full understanding of the present invention, reference should now be made to the following detailed description of the preferred embodiments of the invention as illustrated in the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  an exploded view of a manual unrolling device according to the invention. 
         FIG. 2  a perspective view of the manual unrolling device with a slightly opened lid cover. 
         FIGS. 3 and 4  are perspective views of the manual unrolling device with a closed lid cover and a foil section pulled out from it. 
         FIG. 5  a section of the manual unrolling device. 
         FIGS. 6 and 7  are a perspective view and a top view, respectively, of a housing with side flaps in a magnified presentation. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The preferred embodiments of the present invention will now be described with reference to  FIGS. 1-7  of the drawings. Identical elements in the various figures are designated with the same reference numerals. 
       FIG. 1  shows a fully disassembled manual unrolling device  100 . It comprises a housing  10  with an inner chamber  13 , in which, for examples, foils  31  can be taken up that are wound onto a winding body  30 . 
     A lid cover  10 , which carries a cutting element  16  at its lower side, is connected to the housing  20  via two hinges  27 . 1 ,  27 . 2 . At its front, the lid cover  10  concludes with a redirecting edge  14  that points downwards. 
     Two parallel pull-off edges  21 ,  22  exhibiting a silicon coating for slip resistance are provided at the front of the housing  20 . A gap is present between them into which the cutting element  16  can move when the lid cover  10  is closed. 
     The front pull-off edge  22  has a discontinuation  23  in the center. In this area, the height is significantly reduced. The rear pull-off edge  21  has a recess in the center into which a leaf spring can dip when it is bent down. 
     At its narrow sides, the housing  20  has side areas with slot-shaped recesses  24 . A side flap  25  that exhibits a holding mandrel  26  is connected at the side areas via a film hinge. Its shape corresponds precisely to the slot-shaped recess  24  such that when placing the side flaps  25  onto the housing  20 , the holding mandrel  26  will be pushed through the recess  24  into the inner space  13  and there will be pushed into the hollow cylindrical winding body  30 . 
       FIG. 2  shows the manual unrolling device  100  in a ready to use state. The foil web  31  is pulled out of the gap between the pull-off edges  21 ,  22  and the still open lid cover  10 . The redirecting edge  14  is already resting on the foil web  31 . Also visible is the discontinuation  29  in the front pull-off edge  22 . 
       FIG. 3  shows the state created after the sudden closing of the lid cover  10 . Closing causes the cutting element  16  to affect a cut  33  through the foil  31 , said cut being, however, interrupted in the area where the discontinuation  29  is located and where the foil, therefore, has not been tightened between the pull-off edges  21 ,  22 . A small bar  32  remains at this location by which the mainly already separated area of the foil  31  is still connected to the foil roll that is located inside of the manual unrolling device  100 . Additional pulling, as indicated by the arrow, will tear off the foil piece at the bar  32 . 
     As shown in  FIG. 4 , a portion of the bar  32  remains as the tip that protrudes from the re-directing edge  14 , said tip being easily gripped subsequently in order to pull out a new piece of the foil. 
       FIG. 5  shows a sectional view of the foil guide in the manual unrolling device  100 . The section plane is located in the center of the manual unrolling device  100 , i.e., it runs through the discontinuation  29 . Shown is the position after the closing of the lid cover  10 . 
     The foil  31  wound onto the winding body  30  runs underneath the inner redirecting edge  15 , then up across the parallel pull-off edges  21 ,  22  and finally under the outer redirecting edge  14  toward the outside. Through the redirecting edges  14 ,  15  that are arranged to the right and left of the pair of pull-off edges  21 ,  22  and that reach deep into the bottom area of the bars that form the pull-off edges  21 ,  22 , the foil  31  has been pulled taut to the pull-off edges  21 ,  22  and tightened across them when the lid cover  10  was closed. In the area of the section plane of  FIG. 5 , the cutting element  16  did not separate the foil because it did not rest tightly on the pull-off edges  21 ,  22 . 
     The leaf spring  28  is bent down such that it causes the return forces onto the lid cover  10  and the foil web  31  guided across it. If the manual unrolling device  100  is no actively longer pushed closed by the user, the lid cover  10  moves abruptly upward and the foil  31  is lifted up as well such that it separates from the slip-resistant and maybe even slightly sticky pull-off edges  21 ,  22 . 
       FIG. 6  shows a perspective view of a side area of the housing  20  with the lid cover removed. The side flap  25  is connected to the housing  20  via a film hinge  25 . 1 . Braces  25 . 2 ,  25 . 3  extend from the housing  20  and from the side flap  25  across the film hinge  25 . 1 , with said braces having the shape of circular sections. The bracings have the effect that the film hinge  25 . 1  on the one hand is supported and on the other hand must be overextended to be able to move the side flap  25  from the open to the closed position. 
       FIG. 7  shows a top view of the arrangement of the side flaps  25 . It is apparent that the slot-shaped recess  24  for receiving the holding mandrel  26  extends to the bottom of the housing  20 . 
     There has thus been shown and described a novel manual unrolling device which fulfills all the objects and advantages sought therefor. Many changes, modifications, variations and other uses and applications of the subject invention will, however, become apparent to those skilled in the art after considering this specification and the accompanying drawings which disclose the preferred embodiments thereof. All such changes, modifications, variations and other uses and applications which do not depart from the spirit and scope of the invention are deemed to be covered by the invention, which is to be limited only by the claims which follow.