Abstract:
A two-roll toilet paper dispenser automatically transfers a new roll into dispensing position once the previous roll is spent or nearly spent. A spring-loaded plate senses the decreasing diameter of the first roll, and once it reaches a predetermined minimum, actuates a linkage that permits a mandrel carrying the two rolls to drop down within the dispenser body and position the second roll for dispensing. The mandrel and track structure permits reloading the dispenser without removing the mandrel. The rolls of toilet paper have adapter plugs in one end only, to ensure that the rolls are placed in the correct orientation within the dispenser.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of application Ser. No. 11/541,666 filed on Oct. 3, 2006. The entire contents of the above-identified application are hereby incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The invention relates to an apparatus for automatically transferring rolls of absorbent material such as toilet paper or other wiping materials, as well as a method for reloading such an apparatus, and rolls of absorbent material specially adapted for use the apparatus. 
         [0004]    2. Description of Related Art 
         [0005]    In conventional multi-roll sheet dispensing apparatus, material from a first roll of absorbent material is incrementally dispensed through a dispensing opening in a housing. In some dispensers, as long as there is material on the first roll, a lever remains in position to prevent a second roll from falling down by gravity. 
         [0006]    U.S. Pat. No. 5,288,032 to Boone et al. is a dispenser of that type. However, in such dispensers, each roll of absorbent material requires two core plugs, which may lead to core plug insertion issues and which also permits a roll of toilet paper to be positioned in either of two orientations, such that the sheets could come from behind and under the roll, instead of the preferred over the top orientation. In addition, there are sometimes retention problems with the spent cores in that the cores are prone to fall out of the dispenser and onto the floor. 
         [0007]    Several attempts have been made to address the above-noted problems including U.S. Pat. No. 5,873,542 to Perrin et al. and a more recent attempt shown in U.S. Pat. No. 6,752, 349 to Moody et al. 
         [0008]    The device of Perrin attempts to solve the issue of the spent cores by using a mandrel. However, the device of Perrin does not automatically transfer the second roll once the first roll runs out. Rather, a user must physically dislodge the mandrel from a stop portion to enable the mandrel to slide down so that the second roll can be accessed. 
         [0009]    The device of Moody is complicated in that it requires not only a specialized latch dog assembly on the mandrel, but also removal of the entire mandrel from the dispenser in order to load a new roll. 
       SUMMARY OF THE INVENTION 
       [0010]    An object of the invention is to overcome one or more of the above-described shortcomings of the prior art, or to alleviate one or more of those shortcomings of the prior art at least in part. 
         [0011]    Another object of the invention is to have a relatively simple device for automatically transferring rolls of absorbent material that can be loaded and reloaded by a simple technique. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The above and other objects and advantages of the invention will become apparent from the following detailed description of preferred embodiments thereof, given with reference to the accompanying drawing figures, in which: 
           [0013]      FIG. 1  is a perspective view of a first embodiment of a dispenser according to the invention in an open position; 
           [0014]      FIG. 2  is an exploded view of the dispenser according to  FIG. 1 ; 
           [0015]      FIG. 3  is a top view of a support mandrel according to an embodiment of the invention; 
           [0016]      FIG. 4  is a side view with the cover removed for clarity showing an embodiment of the invention when the mandrel is in a first position; 
           [0017]      FIG. 5  is a side view similar to that of  FIG. 4 , when the mandrel has been freed to move to its second position; 
           [0018]      FIG. 6  is a sectional view showing an embodiment of the invention when the dispenser cover is closed and the mandrel is in a second position; 
           [0019]      FIG. 7  is a sectional view showing the mandrel in the first position and the sensor plate in a second position; 
           [0020]      FIG. 8  is a side view of a transfer link according to an embodiment of the invention; and 
           [0021]      FIG. 9  is a perspective view of the core plug  90  of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0022]      FIG. 1  shows a dispensing device  100  for automatically transferring a second roll (see R 2  in  FIG. 4 ) of absorbent material to be dispensed when a first roll R 1  is spent or substantially spent. 
         [0023]    With respect to  FIGS. 1 and 2 , the dispensing device  100  includes a main body having a back portion  10  and first and second side portions  15 ,  20 . A cover  30  is pivotally mounted to the first and second side portions  15 ,  20  using, for example, pins  13  and clips  18 , with pins  13  passing through openings  14  in cover  30 , then through slots  12  in back portion  10 , and then through bores  22  in side portions  15 ,  20 . However, any known manner of connecting two elements that pivot with respect to each other including, cotter pins, nut/bolt/washer combinations and any other element is contemplated by the present invention. As shown in  FIG. 1 , the side portions  15 ,  20  are nested within back portion  10 , and secured for example by screws (not shown) passing through slots  17  on the side portions  15 ,  20  and threaded bores  11  on the back portion  10 . The cover  30  is pivotal between an open loading position as seen in  FIG. 1  and a closed dispensing position. The cover  30  may include a transparent portion  85  as shown in  FIG. 2  so that a user can see whether there is a second roll of absorbent material in the dispenser  100  without opening the cover  30 . 
         [0024]    As shown in  FIG. 2 , each of the side portions  15 ,  20  includes a mandrel channel. Left-hand side portion  15  includes mandrel channel  16 . Right-hand side portion  20  includes mandrel channel  21 . 
         [0025]    A support mandrel  40  is slidably positioned in the mandrel channels  16 ,  21 . The support mandrel  40  has first and second roll holding elements  42 ,  44 . The support mandrel  40  in use moves automatically between a first position for dispensing sheets of absorbent material from a first roll R 1  of absorbent material contained on the first roll holding element  42  as shown in  FIG. 4  and a second position for dispensing sheets of absorbent material from a second roll R 2  of absorbent material contained on the second roll holding element  44  as shown in  FIG. 6 . As shown in  FIG. 6 , the first roll R 1  of absorbent material is spent or substantially spent when the support mandrel  40  is in the second position. 
         [0026]    In the embodiment of  FIGS. 2 and 3 , the support mandrel  40  includes a flange  45  having first and second opposing sides. Guide elements  41 ,  43  extend in a first direction from the first side of the flange  45  and have a first diameter. The roll support elements  42 ,  44  extend from the second side of the flange  45  in a second direction opposite the first direction. The roll support elements  42 ,  44  are each tapered from a proximal end to a free distal end. The diameter of the proximal end closely corresponds to the inner diameter of a roll of toilet paper, so as to hold the same rotatably but with as little play as possible. The distal ends have a diameter that is greater than the diameter of the guide elements  41 ,  43 , but less than the diameter of the proximal ends. That difference in diameter between the distal ends and the guide elements, and the fact that channel  16  is narrower than channel  21 , means that the mandrel can be inserted into the dispenser only in one orientation, i.e., in this embodiment, with the free distal ends pointing to the right as the dispenser is viewed from the front. 
         [0027]    Each roll support element  42 ,  44  is preferably coaxial with a corresponding one of the guide elements  41 ,  43 . The proximal end of the roll support elements  42 ,  44  is preferably non-rotatable. 
         [0028]    As shown in  FIG. 2 , the dispenser also includes a sensor plate  50  that is disposed between side portions  15 ,  20  and pivotally mounted thereto via pins  54 ,  58  received in openings  14 ,  26 . The sensor plate  50  is urged forwardly by a spring  70  that is connected at its upper end to a boss on the outer side of side portion  20 , and at its lower end to a pin  59  that projects laterally from sensor plate  50  through an arcuate track  24  formed in side portion  20 . 
         [0029]    Sensor plate  50  bears via roller  52  against the outer periphery of a lower roll R 1  of toilet paper. As the toilet paper is withdrawn from roll R 1  by users, spring  70  urges the roller  52  to maintain in continuous contact with roll R 1 . Thus, as the toilet paper on roll R 1  is consumed, the diameter of that roll steadily diminishes, and the plate  50  gradually pivots forwardly, causing pins  59  and  51  to travel forwardly in arcuate slots  24  and  19 , respectively. 
         [0030]    Pin  51  of sensor plate  50  projects through arcuate slot  19 , and is received in the generally triangular opening  61  of a slide arm  60  (see  FIGS. 2 and 4 ). Slide arm  60  is mounted for vertical sliding movement on the outer side of side portion  15 , and even with the cover removed as in  FIG. 4 , most of the slide arm is in this embodiment concealed by the lateral parts of back portion  10 . 
         [0031]    Slide arm  60  coacts with a transfer link  55  that is pivotally mounted at its lower end to the outer side of side portion  15 . Transfer link  55  includes an upper distal end that contacts the distal end of the slide arm. The upper distal end of transfer link  55  includes a projecting element  56  that passes through an opening  31  formed in side portion  15 . Projecting element  56  is moveable from a position as shown in  FIGS. 1 and 4  in which it blocks the channel  16  and forces mandrel  40  to stay in the position shown in  FIG. 4 , to a position as shown in  FIG. 5  where transfer link has been pivoted counterclockwise relative top the position shown in  FIG. 4 , and projecting element is withdrawn from the channel to permit the mandrel to slide downwardly and position roll R 2  for dispensing. 
         [0032]    As noted above, as the diameter of roll R 1  decreases with the withdrawal of toilet paper from the roll, pin  51  travels forwardly in arcuate slot  19 . Because the distal end of pin  51  is also received in the opening  61  of slide arm  60 , arm  60  is moved progressively vertically upwardly as pin  51  travels forwardly in slot  19 . So long as the vertical front-facing surface of the upper end of slide arm  60  is contacting the vertical rear-facing surface of the upper end of transfer link  55 , the transfer link  55  is prevented from pivoting counterclockwise, and the projection  56  is kept in the channel  16  through opening  31 , thereby blocking the guide element  43  and preventing the mandrel from dropping down ( FIG. 4 ). 
         [0033]    However, once the lower roll R 1  is empty or nearly empty (or, more generally, has reached a predetermined minimum diameter corresponding to a forward position of pin  51  in slot  19 ), the slide arm  60  has been raised sufficiently high so as to be free of the blocking contact with the upper end of transfer link  55 . Then, the weight of upper roll R 2  bearing on the inclined upper surface of projection  56  via guide element  43  causes transfer link  55  to pivot counterclockwise (relative to the vantage point of  FIG. 4 ). The oppositely-inclined surface  57  of transfer link  55  on the outside of side portion  15  at this time coacts with slide arm  60  to raise the same to its maximum vertical position, with pin  51  resting in the bottom of triangular opening  61 , as shown in  FIG. 5 . 
         [0034]    The mandrel  40  bearing fresh upper roll R 2  and spent or nearly spent lower roll R 1  is then free to drop down to the position shown in  FIG. 6 , in which roll R 2  is in dispensing position (albeit slightly higher than the dispensing position of roll R 1  in  FIG. 4 ), and in which the lower end of mandrel  40  is confined within the dispenser by cover  30  (channels  16 ,  21  being open at their upper and lower ends). As the full roll R 2  drops down, it deflects the sensor plate  50  backwardly against the action of spring  70 , as shown in  FIG. 6 , so that projection  56  returns to its blocking position inside channel  16 . Although there is no mandrel part above projection  56  at this point, its blocking position prevent a user from pushing roll R 2  upwardly into the dispenser housing and out of its dispensing position. 
         [0035]    Even as the roll R 2  is depleted, sensor plate  50  remains deflected rearwardly and projection  56  remains in the blocking position in channel  16 , by virtue of the mandrel  40  in this dropped-drown position bearing against the lateral arm  53  provided on sensor plate  50   
         [0036]    It is also preferred to include a mandrel channel brake  75  at a lower end of one of the mandrel channels ( 16  in the embodiment of  FIGS. 2 and 4 ) that slows the movement of the support mandrel  40  between the first and second positions. The mandrel channel brake  75  may also serve to prevent the support mandrel from being pushed up into the cover  30 . The mandrel channel brake  75  preferably includes a spring  76  urging the mandrel channel brake  75  into the mandrel channel  16  to slow the movement of the support mandrel  40 . 
         [0037]    The dispensing device  100  preferably includes a locking mechanism  80  connected to the cover  30  for locking the cover  30  to the back portion  10 . 
         [0038]    In a presently preferred embodiment, the mandrel channels  16 ,  21  and/or the guide elements  41 ,  43  may include motion control grease to control the rate of descent of the support mandrel  40  from the first position to the second position. 
         [0039]    In a presently preferred embodiment, the mandrel channels  16 ,  21  are configured so that when the support mandrel  40  is in the second (dropped-down) position and when roll R 2  is a full or substantially full roll, the support mandrel  40  is prevented from being removed from the dispenser even when the cover is in the open position. 
         [0040]    As shown in  FIG. 2 , the mandrel channels  16 ,  21  are nearly mirror images of each other except that one channel  16  is thinner than the other mandrel channel  21  (and includes opening  31  for projection  56 , as discussed above). Each mandrel channel  16 ,  21  include a wider portion  16   a,    21   a  at a top thereof for insertion of the support mandrel  40 . The mandrel channels  16 ,  21  also each have a first substantially vertical portion  16   b,    21   b  adjacent the wider portion  16   a,    21   a,  an angled portion  16   c,    21   c  adjacent the first substantially vertical portion  16   b,    21   b  that is angled toward the back portion  10  and a second substantially vertical portion  16   d,    21   d  at a bottom of the mandrel channels. 
         [0041]    When the support mandrel is in the second position, guide element  43  and the distal end of roll support element  44  of the support mandrel  40  are at the junction between the first substantially vertical portion  16   b,    21   b  and the first angled portion  16   c,    21   c.  Due to the substantial remaining thickness of the roll R 2  and because of the angled portions  16   c,    21   c,  sensor plate  50  prevents the support mandrel  40  from being removed from the dispenser even when the cover  30  is open. Once sufficient absorbent material has been removed from the second roll R 2 , the support mandrel  40  can be withdrawn from the open dispenser at the bottoms of the second substantially vertical portions  16   d,    21   d.    
         [0042]    Preferably, prior to the material on roll R 2  being completely or substantially completely removed from the second roll R 2 , maintenance personnel will see through window  85  that no upper roll is present, and a new roll of absorbent material will be placed on the empty roll holding element  42 . Roll holding element  42  bearing a newly-replaced fresh roll R 1  may then be flipped upwardly using elements  43  and  44  still resident in channels  16  and  21 , respectively, as a fulcrum, this maneuver involving both pivoting and translation of these elements. The wider portion  16   a,    21   a  facilitate introduction of the guide element  41  and the roll holding element  42  bearing fresh roll R 1  into the mandrel channels  16 ,  21 , and this operation can be performed easily and without ever removing the support mandrel  40  from the dispensing device  100 . 
         [0043]    As noted previously, roll holding elements  42 ,  44  are wider at their base and narrower at their free distal ends. The rolls of absorbent material to be used in the dispenser of the invention preferably include a core plug  90 , as shown in  FIGS. 1 and 9 . The core plug  90  fits snugly into a roll of absorbent material, and preferably has an outer diameter that will be a friction fit via surface  92  inside a standard cardboard toilet paper core. Each of the first and second roll holding elements  42 ,  44  has a distal end whose diameter preferably corresponds to the diameter of a hole  91  in the core plug  90 , in that the core plug fits over the distal end of the roll holding elements and is rotatable relative thereto, but with as little play as possible. 
         [0044]    In operation, as seen in  FIGS. 4 and 5 , the absorbent material is removed from the first roll R 1  until this roll is depleted or substantially depleted. The sensor plate  50  detects that the roll R 1  is depleted and then based on the position of the slide arm, as set forth above, the weight of the second roll R 2  causes the transfer link to be shifted out of the guide groove  16 , enabling the mandrel  40  with the second roll thereon to drop under the influence of gravity. The mandrel moves from the first position as seen in  FIG. 4  to the second position as seen in  FIG. 5 . 
         [0045]    Hopefully not long thereafter, a maintenance person will notice that the first roll R 1  is spent and must be replaced with a new roll. To replace the roll, the maintenance person opens the cover  30  of the dispensing device  100 . The maintenance person then places a new roll of absorbent material on an end of the support mandrel  40 . In the shown embodiment, the new roll is placed on roll holding element  44 . 
         [0046]    However, as would be recognized by one of ordinary skill in the art, the support mandrel is symmetrical about a horizontal axis and the new roll would be placed on the appropriate end that needs replacement. The maintenance person would then pivot the support mandrel  40  about an axis of the roll holding element  42 , while the support mandrel  40  is contained within the dispensing device  100 . Of course, if the second roll were also sufficiently depleted, the maintenance person could remove the support mandrel  40  from the mandrel channels  16 ,  21  and add new rolls to both the first and second roll holding elements  42 ,  44 . 
         [0047]    If the maintenance person were only replacing a single roll, after pivoting the support mandrel  40 , the maintenance person would insert the roll holding element  44  of the support mandrel  40  into the mandrel channels  16 ,  21  at the wider portion  16   a,    21   a  at the top of the dispensing device  100 . The maintenance person would then close the cover  30 . Of course, if the cover  30  were to include a locking mechanism  80 , the maintenance person would lock and unlock the locking mechanism  80  at the appropriate times in the loading process. 
         [0048]    In the presently preferred embodiment, the new rolls of absorbent material each come pre-packaged with a core plug  90  in only one end to assist in easy installation by making the roll insertable in only one orientation. 
         [0049]    Another aspect of the present invention is therefore a roll of absorbent material as depicted for example in  FIG. 1  and as described above. The inventive roll of absorbent material is characterized by having openings of distinctly different diameters at its respective sides. In a preferred embodiment, the inventive roll of absorbent material is an otherwise conventional roll of toilet paper having a cardboard core, into one end of which is inserted a core plug  90  as described above. Core plug  90  is preferably an injection molded plastic component, whose outer diameter  92  is a snug fit inside the cardboard core. The core plug preferably also includes a small radially outwardly projecting flange  93  whose outer diameter is greater than the inner diameter of the cardboard core, to prevent the plug from being inserted too deeply. The roll of absorbent material according to the invention includes such a core plug in one end only, to oblige a maintenance person to place the roll into the dispenser in the correct orientation (over the top dispensing, as described above). 
         [0050]    Core plug  90  has a circular central opening  91 , which permits mandrel  40  to be made in one piece, because the plugs  90  can spin on the free ends of the roll holding elements  42  and  44 . Alternatively, the central opening  91  may be formed in any desired non-circular shape. In this case, the distal ends of roll holding elements  42  and  44  are made in a complementary non circular shape, and the roll holding elements are fashioned so as to be rotatable relative to the body of mandrel  40 , or alternatively, the non-circular distal ends of roll holding elements  42  and  42  are made rotatable relative to the remainder of roll holding elements  42  and  44 . 
         [0051]    The invention has been described in detail with respect to presently preferred embodiments. However, it will be apparent to those of skill in the art that changes or modifications may be made without departing from the spirit of the invention. The invention should not be limited by the disclosed embodiments and rather should be defined by the appended claims.