Abstract:
The invention consists of a paper towel dispenser for dispensing individual sheets of paper towels from a roll of paper having regularly spaced apart lines of partial severance. The dispenser is comprised of a housing and a housing door which can be pivotally opened to allow a roll of sheet material to be inserted into the dispenser. The dispenser has a funnel-shaped exit to allow the end of the roll to protrude in order to be grasped by the user. A paper towel tearing member is located adjacent to the exit aperture of said funnel and the opening of this member is adjustable in order to vary the size of the opening of the dispenser. This adjustment of the exit size creates an adjustment in the position at which the sheet tears away from the roll to allow the use of different types of sheet material in a single dispenser.

Description:
RELATED APPLICATION 
     This application is a continuation-in-part of U.S. patent application Ser. No. 09/709,372 filed Nov. 13, 2000, all of which is herein incorporated by reference. 
    
    
     FIELD 
     This invention relates to a dispenser for sheet material, particularly to a dispenser that dispenses individual sheets of a material, such as paper towels, from the center of a coreless roll divided into a plurality of sheets by partially severed spaced apart lines. 
     BACKGROUND 
     A number of dispensers exist in the prior art for dispensing paper towels and similar sheet materials. One method of dispensing involves a “center-pull” mechanism whereby the sheet material is removed from the center of a coreless roll. The sheet material is pulled through a restricted opening that frictionally resists the pulling motion from the user. This resistance results in the sheet material tearing away into individual sheets at predetermined points marked by partially severed lines. 
     The most common design of a center-pull dispenser uses a cone or funnel shaped nozzle to provide the opening for resisting and dispensing the sheet material. This design provides a large initial entrance for the end of the sheet material roll that allows for easy insertion of the end of a new roll, while also having the restricted exit opening necessary to provide sufficient resistance to allow tearing of the perforations. 
     There are a couple of problems with the current center-pull dispenser designs. First, some dispensers have the point of the opening formed by the casing which is of a relatively inexpensive plastic. The repeated passage of the sheet material against the exit opening wears down this plastic, eventually making the opening too large to provide proper resistance for tearing the perforations. In most cases, the entire unit must be replaced to resolve this problem. 
     A second problem is the need for multiple dispensers for different types of sheet materials. Different grades of sheet material require exit openings of different sizes and shapes. Ideally, a sheet material dispenser should be adjustable to allow dispensing of different grades of sheet material. 
     Therefore, it is an object of this invention to provide a sheet material dispenser that has a modified exit opening that eliminates wear caused by friction from the sheet material. It is a further object of this invention to provide a sheet material dispenser that minimizes the chance of the sheet material jamming in the dispenser during operation. 
     It is a further object of this invention to provide a sheet material dispenser with an exit opening that can be adjusted in shape or size to allow the dispensing of different grades of sheet material. 
     SUMMARY 
     The invention consists of a paper towel dispenser for dispensing individual sheets of paper towels from a roll of paper having regularly spaced apart lines of partial severance. The dispenser is comprised of a housing and a housing door which can be pivotally opened to allow a roll of sheet material to be inserted into the dispenser. The dispenser has an exit aperture at the bottom to allow the end of the roll to protrude in order to be grasped by the user. This exit aperture is preferably located between the axis of the dispenser and the housing door in such a way as to provide space between the roll end and the wall on which the dispenser is mounted for a user to grasp the roll end. 
     The interior of the dispenser has a funnel-shaped platform which supports the roll of sheet material above the exit of the dispenser. The funnel-shaped platform has a rotatable ring attached at its exit. The rotatable ring has a slot which aligns with a corresponding slot in the platform to allow for the sheet material to be passed through when loading a new roll of sheet material into the dispenser. The rotatable ring is then rotated so the slot in the ring is no longer aligned with the slot in the platform. The misalignment of the two slots reduces the chances of the sheet material jamming in the platform slot during dispensing. 
     A paper towel tearing member is located adjacent to the exit aperture of the funnel and the opening of this member is adjustable in order to vary the size of the opening of the dispenser. This adjustment of the exit size creates an adjustment in the position at which the sheet tears away from the roll to allow the use of different types of sheet material in a single dispenser. 
     Optionally, a wear-resistant ring, preferably made of metal or hard plastic, is located in the housing and surrounds the exit opening, except for a slot, to permit the passage of the roll end. A spacer in the housing door enters a slot in the ring when the housing door-is closed to provide a solid ring enclosing the entire exit opening. When the user pulls on the roll end the material rubs along the plate and the friction creates enough resistance to allow separation of individual sheets of material along predetermined perforations. The ring will be extremely resistant to the wear caused by the repeated use of the dispenser. One preferred shape for the ring is an elongated rectangle. 
     The adjustment of the paper towel tearing member may be provided by a sliding plate composed of the same wear-resistant material as the ring. 
     Preferably, the ring is also removable, to allow replacement of the ring in order to adjust the shape of the exit opening to accommodate different grades of sheet material. 
     The ring and sliding plate assemblies can also be combined in the paper towel tearing member to provide the widest range of adjustment possibilities. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention itself, both as to organization and method of operation, as well as additional objects and advantages thereof, will become readily apparent from the following detailed description when read in connection with the accompanying drawings: 
     FIG. 1 is a side view of a closed dispenser; 
     FIG. 2 is an end view of the base of a closed dispenser; 
     FIG. 3 is an interior view of the housing door; 
     FIG. 4 is a cut-away view of the housing; 
     FIG. 4 a  is a close-up of the lower interior of the housing without the platform funnel collar visible; 
     FIG. 4 b  is a close-up of the lower interior of the housing with the platform funnel collar visible; 
     FIG. 5 is an end view of the housing; 
     FIG. 6 is an interior view of the closed dispenser with the platform removed; 
     FIG. 6 a  is an interior view of the closed dispenser showing the sliding plate in an extended position; 
     FIG. 7 is a cross section of the adjustment mechanism in the closed dispenser; 
     FIG. 8 is a cross section of the adjustment mechanism showing the sliding plate in an extended position; 
     FIG. 9 is a cut-away view of an alternative embodiment for the adjustment mechanism; and 
     FIG. 10 is a typical ring, shown in an elongated rectangular shape. 
    
    
     DETAILED DESCRIPTION 
     FIG. 1 shows the closed dispenser  10  for dispensing individual sheets from a roll of sheet material divided into a plurality of sheets by partially severed spaced apart lines. The dispenser  10  consists of a housing door  12  and a housing  14 . In the embodiment shown, a funnel outlet  16  is preferably located forward of a center axis A—A of the closed dispenser  10 . By locating the funnel outlet  16  forward of the center axis A—A, there is an increase in the space available to the user for grasping the projecting roll end  70  when the dispenser is mounted on a wall. The funnel outlet  16  is also shown with an optional adjustment mechanism  20  located behind the funnel exit opening  18 . In the current embodiment, the hinges  40 , which allow the closed dispenser  10  to be opened by rotating the housing door  12  away from the housing  14 , are located on an exterior side of the dispenser  10 . A locking clasp (not shown) or similar mechanism is used to hold the housing door  12  in the closed position. The roll end  70  of the sheet material projects through the exit opening  18  to be grasped by a user. 
     FIG. 2 shows an end view of the closed dispenser  10 , with the funnel outlet  16  and the exit opening  18 . The adjustment mechanism  20  is also shown. In the current embodiment, the adjustment mechanism  20  consists of a sliding plate  22 . A portion of a ring  30  defining the exit opening  18  is also visible around the exit opening  18  and below the sliding plate  22 . The ring  30  and the sliding plate  22  are made of metal to prevent any wear from the repeated passage of the sheet material. However, any suitably resistant material, such as a hard plastic, could also be used. 
     FIG. 3 shows the interior of the housing door  12 . A spacer  28  is located at the edge of the exit opening  18  (as shown in FIG. 2) when the housing door  12  is closed against the housing  14  (as shown in FIG.  4 ). 
     FIGS. 4,  4   a , and  4   b  show the base of the interior of the housing  14 . Any conventional method can be used to secure the housing  14  to a wall for use. For example, holes may be included in the back of the housing  14  to allow for screws to secure the housing  14  to a wall. The two projections  32  and  34  (see FIG. 4 a ) in the funnel outlet  16  support a platform  36  which holds the roll (not shown) of sheet material and allows the roll to rotate as the roll end  70  (see FIG. 1) is pulled by the user. The platform  36  is attached to the housing  14  at slots  44 . The platform  36  has a funnel-shaped opening  38  dimensioned to fit inside the funnel outlet  16  of the housing  14  and to allow space between the end of the funnel-shaped opening  38  and the exit opening  18  for the ring  30  and sliding plate  22 . 
     The platform  36  has a collar  80  with a slot  82  attached at the end of the funnel-shaped opening  38 . The collar  80  is rotatable such that slot  82  can be aligned with the slot  37  in the platform  36  to insert a new roll as described below. During operation, the slot  82  is misaligned from the slot  37  to prevent jamming of the dispenser that may otherwise result from the sheet material being caught in the slot  37  during dispensing. 
     As seen in FIG. 4 b , the collar  80  extends down to the sliding plate  22 . In an embodiment without the sliding plate  22 , the collar  80  should extend to the ring  30  which surrounds the exit opening  18 . In this manner, the sheet material is surrounded at all times during dispensing, thereby minimizing the risk of the sheet material becoming jammed in any part of the dispenser  10  during dispensing. The sliding plate  22  and the ring  30  are located immediately above the exit opening  18 . 
     The sliding plate  22  and ring  30  are mounted on the housing  14  because of the large size of the housing  14  compared to the housing door  12 . The large size of the housing  14  is a result of locating the funnel outlet  16  forward of the center axis A—A (as shown in FIG.  1 ). While the described configuration is considered optimal, it is conceivable that either or both of the sliding plate  22  and the ring  30  could be located on the housing door  12  in an alternative embodiment. 
     FIG. 5 shows an end view of the exterior of the housing  14 . The ring  30  has a gap  29  to accept the spacer  28  (shown in FIGS.  3  and  6 ). The shape of the ring  30  defines the exit opening  18  and the ring  30  is preferably removable to allow the use of differently shaped rings for different grades of sheet material without replacing the dispenser  10  (as shown in FIG.  1 ). 
     FIG. 10 shows a typical ring  30 , shaped as an elongated rectangle. The elongated rectangular shape allows for tearing of the sheet material when the user pulls the roll end in any direction. Due to the small size of the ring  30 , it may be possible to provide a space in the housing door  12  or the housing  14  to store excess rings to allow a single dispenser to handle various grades of sheet material. 
     FIG. 6 is an interior view showing the base of the closed dispenser  10  with the platform  36  (shown in FIG. 4) removed. The spacer  28  is inserted into the gap  29  (shown in FIG. 5) in the ring  30  to completely enclose the exit is opening  18  when the housing door  12  is closed against the housing  14 . The sliding plate  22  is shown in a fully retracted position, leaving the entire exit opening  18  in the ring  30  exposed. Preferably, the sliding plate  22  has a rounded end to match the rounded shape of the exit opening  18 . FIG. 6 a  shows the same view with the sliding plate  22  in a partially extended position to partially cover the exit opening  18 . 
     FIG. 7 is a cross section of the adjustment mechanism  20 . The sliding plate  22  is located directly above the ring  30  and the spacer  28 . The position of the sliding plate  22  is adjusted to reduce or enlarge the size of the exit opening  18 . In the embodiment shown, a threaded fastener  24  connected to the sliding plate  22  and to an adjustment knob  26  provides this adjustment. The rotation of the adjustment knob  26  moves the sliding plate  22  along the fastener  24  while washer  27  retains fastener  24  in position. The adjustment knob  26  is positioned such that it can be accessed from the exterior of the closed dispenser  10  (as shown in FIG.  1 ). As a result, it may optionally include some anti-tamper means to prevent user interference with the dispensing process such as a unique screw head. FIG. 8 shows the same view with the sliding plate  22  in a partially extended position, partially covering the exit opening  18 . 
     FIG. 9 shows an alternative embodiment for the adjustment mechanism  20 . A pair of curved bars  50  and  52  are used in place of the ring  30 . A fastener  54  passed through blocks  56  connects the curved bars  50  and  52 . The fastener  54  can be tightened (to expand the opening) or loosened (to reduce the opening). A hole  60  is positioned to provide access to the fastener  54  for adjustment. A bar  62 , preferably attached to the housing door  12 , rests on top of the ends of the curved bars  50  and  52  to fully enclose the exit opening  18 . This alternative embodiment is shown without the sliding plate  22  (as seen in FIG.  4 ), however, it can be anticipated that a design that combines the curved bars  50  and  52  with a sliding plate  22  is also possible. 
     In operation of a unit designed according to the preferred embodiment, a roll of sheet material is mounted inside the closed dispenser  10 . The roll end  70  of the sheet material roll (see FIG. 1) runs through the funnel-shaped opening  38  in platform  36 , through the collar  80  and through the exit opening  18 . The user pulls the sheet material, which frictionally contacts the ring  30 . The force exerted by a user, and the associated friction against the ring  30 , increases until the partially severed line extends out of the exit opening  18  a predetermined distance, at which point the sheet material tears along the partially severed line. The torn end of the sheet material protrudes through the exit opening  18 , ready for use by another user. 
     Installing and replacing a roll of sheet material is facilitated by the housing construction. The housing door  12  is opened and pivoted out of position along the hinges  40 . A roll of sheet material is then inserted into the housing  14 , which is mounted to a wall. The collar  80  is rotated so the slot  82  is aligned with the slot  37  in the platform  36 . The end of the roll is then passed through the slot  37 , the slot  82  in the collar  80  and the gap  29  in the ring  30 . The collar  80  is then rotated so that the slot  82  is no longer aligned with the slot  37 . The collar  80  prevents the sheet material from being caught in the slot  37  during dispensing and therefore greatly reduces the chance -of the dispenser jamming. The housing door  12  is then closed against the housing  14 . The spacer  28  fits into the gap  29  in the ring  30  to form a closed ring surrounding the protruding roll end  70 . Other embodiments would be expected to function in a manner similar to the one described above. 
     Accordingly, while this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to this description. It is therefore contemplated that the appended claims will cover any such modifications or embodiments as fall within the scope of the invention.