Abstract:
Apparatus, systems, and methods in which a sheet product dispenser comprises a front cover moveably coupled with a housing back, and an overfill prevention protrusion disposed in an internal storage space defined by the front cover and housing back. The interior storage space is configured to hold a plurality of stacked sheets. The front cover and/or the housing back includes an opening for dispensing the plurality of sheets. The overfill prevention protrusion is configured to gradually interfere with the plurality of stacked sheets from fitting in the interior storage space. For example, the protrusion may be configured to prevent the plurality of stacked sheet from stacking in a linear fashion (e.g., in a fashion parallel to a wall of the housing back).

Description:
[0001]    This application claims the benefit of priority to U.S. provisional patent application Ser. No. 61/409632, filed on Nov. 3, 2010. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The field of the invention is dispensers, more specifically, overfill prevention for sheet product dispensers. 
       BACKGROUND 
       [0003]    When a technician fills a paper towel dispenser there is a tendency to overfill the dispenser with as much paper product as possible, in order to reduce the number of times the dispenser needs to be serviced. However, if too much product is added, the stack of paper towels will have a buildup of pressure. This increased pressure makes dispensing difficult and increases the likelihood of tabbing or ripping the paper towels. 
         [0004]    Numerous sheet product dispensers have been designed with overfill prevention mechanisms. U.S. Pat. No. 5,884,805 to Tramontina, for example, describes an overfill feature that will prevent the dispenser&#39;s cover from being closed if too much product is loaded into the dispenser. Tramontina specifically describes an overfill bracket that will be displaced from its normal position, thus preventing the front cover from engaging with the housing back. Since the front cover cannot close when the dispenser is overfilled with sheet product, the dispenser technician will need to remove enough product to allow the overfill bracket to move back to its normal position and allow the cover to engage with the closure mechanism. 
         [0005]    This and all other extrinsic materials discussed herein are incorporated by reference in their entirety. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply. 
         [0006]    Another overfill prevention mechanism is described in U.S. Pat. No. 6,520,372 to Phelps. Phelps describes a moveable housing bottom that lifts up as the dispenser cover is opened, thus reducing the internal storage space that can accept folded product. When the cover is closed, the bottom drops down increasing the internal storage space which in return prevents the overfilling of the folded product. U.S. Pat. No. 374,065 to Taylor also describes an overfill prevention feature that limites available storage capacity when the front cover is open, and increases storage capacity when the front cover is closed. 
         [0007]    In addition, U.S. Pat. No. 6,920,999 to Taylor describes an overfill mechanism that requires the technician to use two hands. This prevents the technician from pushing down and compressing (e.g., stuffing) the stack of folded product into the dispenser in order to add extra sheet product, thus preventing overfilling. 
         [0008]    Unfortunately, the prior art requires complex linkages and/or moving parts. It has yet to be appreciated that an overfill prevention feature can comprise a simple single non-moving part. 
         [0009]    Thus, there is still a need for improved overfill prevention features for sheet product dispensers. 
       SUMMARY OF THE INVENTION 
       [0010]    The inventive subject matter provides apparatus, systems, and methods in which a sheet product dispenser comprises a front cover moveably coupled with a housing back, and an overfill prevention protrusion disposed in an internal storage space defined by the front cover and housing back. The interior storage space is configured to hold a plurality of stacked sheets. The front cover and/or the housing back includes an opening for dispensing the plurality of sheets. The overfill prevention protrusion is configured to gradually interfere with the plurality of stacked sheets from fitting in the interior storage space. For example, the protrusion may be configured to prevent the plurality of stacked sheets from stacking in a linear fashion (e.g., in a fashion parallel to a wall of the housing back). 
         [0011]    The dispenser preferably includes a stacking surface for stacking the plurality of sheets. In addition, the overfill prevention protrusion preferably includes a first surface disposed in a plane that intersects a plane defined by the stacking surface. In some embodiments, the angle of intersection is at least 15 degrees, more preferably at least 30 degrees, most preferably at least 45 degrees. 
         [0012]    Unless the context dictates the contrary, all ranges set forth herein should be interpreted as being inclusive of their endpoints, and open-ended ranges should be interpreted to include commercially practical values. Similarly, all lists of values should be considered as inclusive of intermediate values unless the context indicates the contrary. 
         [0013]    In other aspects of some preferred embodiments, the overfill prevention protrusion preferably extends into the interior storage space at a length of at least 20% of a width of the stacking surface, more preferably at least 30%, most preferably at least 50%. 
         [0014]    In yet other aspects of some preferred embodiments, the front cover and housing back are rotatably coupled. However, translating couplings are also contemplated. The dispenser preferably includes a latching mechanism for locking the front cover and housing back together, thus controlling access to the internal storage space. 
         [0015]    Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
         [0016]      FIG. 1  is a front view of one embodiment of a dispenser, without sheet product in the internal storage space. 
           [0017]      FIG. 2  is a side view of the housing back of the dispenser of  FIG. 1 . 
           [0018]      FIG. 3  is a front view of the housing back of the dispenser of  FIG. 1  with sheet product disposed in the internal storage space. 
           [0019]      FIG. 4  is a side view of the housing back of the dispenser of  FIG. 1  with sheet product disposed in the internal storage space. 
           [0020]      FIG. 5  is a front view of the housing back of the dispenser of  FIG. 1  with sheet product disposed in the internal storage space beyond the overfill prevention protrusion. 
           [0021]      FIG. 6  is a side view of the housing back of the dispenser of  FIG. 1  with sheet product disposed in the internal storage space beyond the overfill prevention protrusion. 
           [0022]      FIG. 7  is a side view of the dispenser of  FIG. 1  with the front cover partly closed due to interference of the stacked sheet product with the front cover. 
           [0023]      FIG. 8  is a side view of another embodiment of a dispenser. 
       
    
    
     DETAILED DESCRIPTION 
       [0024]    One should appreciate that the disclosed techniques provide many advantageous technical effects including a simple non-moving solution for preventing overfilling of sheet product dispensers. 
         [0025]    The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed. 
         [0026]      FIG. 1  shows a front view of a towel dispenser assembly  1 . Dispenser  1  comprises a housing back  2  and a front cover  8  (see  FIG. 7 ). Front cover  8  is moveable between an open position for accessing cavity  4  (for loading sheet product), and a closed position (for storing and dispensing the sheet product). In  FIG. 1 , front cover  8  has been removed and sheet product  10  ( FIGS. 3 and 4 ) has not yet been placed in cavity  4 .  FIG. 1  also shows fill level indicator  3  and an overfill protrusion  6 . Indicator  3  shows an appropriate level for filling cavity  4  with sheet product  10 . Overfill protrusion  6  prevents closure of front cover  8  when sheet product  10  has been filled beyond indicator  3 . Dispenser  1  also has an opening  11  for dispensing sheet product, which could alternatively be located on front cover  8  rather than housing back  2 . 
         [0027]      FIG. 2  shows a side view of dispenser  1 , without front cover  8  or sheet product  10 . Housing back  2  has a stacking surface  14  for stacking sheet product  10  and an overfill protrusion  6  for preventing cavity  4  from being overfilled. Protrusion  6  extends from housing back  2  into cavity  4  and has a first surface  13  that is angled with respect to stacking surface  14 . Vertical wall  5  can include fasteners for fastening dispenser  1  to a surface such as a wall. Pivot coupling  7  is used to rotatably couple front cover  8  to housing back  2 . 
         [0028]    The angle between first surface  13  and stacking surface  14  is preferably at least 15 degrees, more preferably 30 degrees, most preferable at least 45 degrees. If the angle is too small, a technician may be able to stuff a stack of sheet product between surfaces  13  and  14 , causing undesirable pressure in the stack of sheet product. 
         [0029]    The width that protrusion  13  extends into cavity  4  is preferably at least 15% of the width of surface  14 , more preferably at least 25%, most preferably at least 50%. If the width of protrusion  13  is too small, overfill position  12  will not be large enough to interfere with front cover  8  from closing. 
         [0030]    While  FIGS. 1 and 2  show surface  13  as a substantially flat surface, those of skill in the art will appreciate that non-planar surfaces could also be used consistently with the inventive subject matter disclosed herein. For example, surface  13  could be concave or convex. In addition, while  FIGS. 1 and 2  show stacking surface  14  on housing back  2 , surface  14  could alternatively be included in front cover  8 . 
         [0031]      FIG. 3  shows a front view of a dispenser  1 , with sheet product  10  disposed in cavity  4  of housing back  2 , just below overfill protrusion  6 .  FIG. 3  shows an acceptable amount of sheet product  10  loaded in dispenser  1 .  FIG. 4  shows a side view of dispenser  1  with an acceptable amount of sheet product  10  loaded in cavity  4 . Sheet product  10  rests on stacking surface  14  and rises to just below first surface  13  of overfill protrusion  6 . Sheet product  10  stacks parallel with vertical wall  5 . 
         [0032]      FIG. 5  shows a front view of dispenser  1  with sheet product  10  overfilling cavity  4  (e.g., beyond level indicator  3  and protrusion  6 ). Protrusion  6  causes sheet product  10  to interference with front cover  8  from coupling with housing back  2 , as best seen in  FIG. 6 . 
         [0033]      FIG. 6  shows a side view of dispenser  1  with sheet product  10  extending into overfill position  12 . When a technician overfills cavity  4  by compressing the stack of sheet product, the stack will expand upward as the technician removes pressure from the stack. As the stack expands upward, it travels along vertical wall  5  until it hits surface  13 , forcing the stack forward into overfill position  12 . This, in turn, prevents front cover  8  from closing. The technician is prompted to remove sheet product until front cover  8  can close properly. 
         [0034]      FIG. 7  shows a side view of towel dispenser assembly  1  with sheet product  10  overfilling cavity  4 . Protrusion  12  interferes with the closure of front cover  8 , alerting the dispenser technician that sheet product must be removed. The technician is prevented from overfilling cavity  4 , thus preventing any pressure buildup within the stack of sheet product  10 . 
         [0035]    The inventive concepts disclosed herein are specifically contemplated for use with rectangular folded paper towels. However, one of skill in the art will recognize that these inventive concepts can be equally applicable with non-rectangular, non-folded, non-absorbent, and/or non-paper sheets of product. As such, the inventive subject matter is not intended to be limited by the term “sheet product.” The advantage of the present invention is a simple overfill prevention feature that does not require the movement of additional parts, which can be applied to numerous kinds of sheet dispensers. 
         [0036]      FIG. 8  shows a dispenser assembly  15 , which has a front cover  16  translatably coupled with housing back  17 . Housing back  17  has tracks  18  configured to engage with protrusions (not shown) on the inside of front cover  16 , thus allowing front cover  16  to slide vertically with respect to housing back  17 . When the interior cavity of dispenser  15  is overfilled with sheet product, front cover  16  is prevented from sliding down to enclose the sheet products. Once sheet product has been removed and the interior cavity is properly filled, front cover  16  slides down to couple with housing back  17 . Latch mechanism  19  interlocks front cover  16  with housing back  17  and controls who may access the cavity of dispenser  15 . 
         [0037]    As used herein, and unless the context dictates otherwise, the term “coupled to” is intended to include both direct coupling (in which two elements that are coupled to each other contact each other) and indirect coupling (in which at least one additional element is located between the two elements). Therefore, the terms “coupled to” and “coupled with” are used synonymously. 
         [0038]    It should be apparent to those skilled in the art that many more modifications besides those already described are possible without departing from the inventive concepts herein. The inventive subject matter, therefore, is not to be restricted except in the scope of the appended claims. Moreover, in interpreting both the specification and the claims, all terms should be interpreted in the broadest possible manner consistent with the context. In particular, the terms “comprises” and “comprising” should be interpreted as referring to elements, components, or steps in a non-exclusive manner, indicating that the referenced elements, components, or steps may be present, or utilized, or combined with other elements, components, or steps that are not expressly referenced. Where the specification claims refers to at least one of something selected from the group consisting of A, B, C . . . and N, the text should be interpreted as requiring only one element from the group, not A plus N, or B plus N, etc.