Patent Publication Number: US-7896285-B2

Title: Sheet product dispenser

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to sheet product dispensers, and more particularly to sheet product dispensers adapted for dispensing sheet product from a roll. 
     Sheet product dispensers can provide a dispensing mechanism including a drive roll coupled to a reciprocating operating lever via one or more gear racks internal to the dispenser that engage a drive gear. Accordingly, sheet product is dispensed via the drive gear in response to user-provided energy via the operating lever. 
     While existing products are suitable for their intended purpose, application of excessive user force, or rate of force application, to the drive roll via the operating lever may result in a tear of the sheet product, thereby requiring dispenser service. Additionally, excessive force, or rate of force application, can result in reduced feed drive component reliability and additional dispenser service. Current approaches to reduce such service requirements include use of sheets having an appropriate strength to resist tears. However, sheet product having appropriate strength to resist tears may not provide desired properties such as absorbency, or facilitate perforation. Accordingly, there is a need in the art for a sheet product dispenser arrangement that overcomes these drawbacks. 
     BRIEF DESCRIPTION OF THE INVENTION 
     An embodiment of the invention includes a dispenser for dispensing sheet product from a supply to a user. The dispenser includes a feed device for dispensing a length of sheet product, an energy storage device in operable communication with the feed device, and a user interface in operable communication with the energy storage device. The user interface is biased in a first direction to a rest position by the energy storage device and is responsive to energy from the user to move in a second direction opposite the first direction and transfer energy to the energy storage device. The energy storage device is in operable connection with the feed device and applies the transferred energy to generate motion of the user interface in the first direction toward the rest position to actuate the feed device and dispense the sheet product. 
     Another embodiment of the invention includes a dispenser for dispensing sheet product from a roll to a user. The dispenser includes a feed roll for dispensing a length of the sheet product from the roll to the user, a spring in operable communication with the feed roll, and a push arm. The push arm is pivotally mounted about an axis disposed proximate one end of the push arm and is in operable communication with the spring and biased in a first direction to a rest position by the spring. The push arm is responsive to energy from the user to move in a second direction opposite the first direction and to transfer the energy to the spring. The spring is in operable connection with the feed roll and applies the transferred energy to generate motion of the push arm in the first direction toward the rest position to rotate the feed roll and dispense the sheet product. 
     A further embodiment includes a method of dispensing sheet product from a supply to a user. The method includes applying energy to an energy storage device via a user interface biased in a first direction to a rest position by the energy storage device. The applied energy moves the user interface in a second direction opposite the first direction. The method further includes transferring the applied energy from the energy storage device to a feed device via the user interface. The transferred energy moves the user interface in the first direction toward the rest position and dispenses the sheet product from the supply to the user. 
     These and other features of the present invention will be better appreciated by reference to the appended drawings and the description which follows. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described in detail below with reference to the various figures wherein: 
         FIG. 1  is a perspective view of a sheet product dispenser in accordance with an embodiment of the invention; 
         FIG. 2  is a schematic diagram showing various parts of a sheet product dispenser in accordance with an embodiment of the invention; 
         FIG. 3  is a schematic detail showing interaction of a clutch bearing and press bar assembly in accordance with an embodiment of the invention; 
         FIG. 4  is a schematic detail showing a unitary support member including a molded-in rack of a press bar assembly in accordance with an embodiment of the invention; 
         FIG. 5  is a schematic front interior view in elevation of the dispenser of  FIG. 1 ; 
         FIGS. 6 and 9  are schematic diagrams showing various parts of the dispenser in accordance with embodiments of the invention; 
         FIG. 7  is a schematic detail showing interaction of a clutch bearing and press bar assembly in accordance with an embodiment of the invention; 
         FIG. 8  is a schematic detail showing a unitary support member including a molded-in rack of the press bar assembly in accordance with an embodiment of the invention; and 
         FIG. 10  is a flowchart of a method of dispensing sheet product in accordance with an embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention is described in detail below in connection with several embodiments for purposes of illustration only. Modifications to such embodiments, within the spirit and scope of the appended claims, will be readily apparent to those of skill in the art. 
     One embodiment of the invention provides an energy storage device to store energy supplied by a user, and release the stored energy to dispense sheet products. As used herein, the terms “sheet product” and “sheet products” are inclusive of natural and/or synthetic cloth or paper sheets. Further, sheet products can include both woven and non-woven articles. Examples of sheet products include, but are not limited to wipers, napkins, tissues, and towels. The energy storage device provides a controlled, consistent force to the sheet independent of an amount or rate of application of force by the user. 
     Referring generally to  FIGS. 1 through 5 , there is shown an embodiment of a sheet product dispenser  10  suitable for dispensing sheet product. Dispenser  10  includes a housing  12  defining an enclosure  14  with an enclosure front portion  16 , enclosure sidewall portions  18 ,  20 , an enclosure upper portion  22 , and an enclosure lower portion  24 . The dispenser  10  optionally includes an inner, modular chassis indicated at  25  to mount the various parts as is known in the art and may be made of any suitable material, such as plastic for example. 
     A dispensing nip  26  in the lower portion  24  of the housing  12  is defined in part by a drive roll  28  with first friction surface  30  defined by members  32  about the shaft of drive roll  28  and a second nip roll  34  having a second friction surface  36  whereby dispensing nip  26  is defined therebetween. At upper portion  22  of housing  12  there are provided hubs indicated at  38  and  40  for rotatably mounting a roll of sheet product in the upper portion  22  of enclosure  14  above dispensing nip  26 . The drive roll  28  is mounted for rotation about a driveshaft mounted in a one-way clutch bearing as is further discussed below. 
     A roll  42 , such as a supply or continuous web of sheet product (the terms roll, supply and web are used interchangeably throughout), is fed downwardly where the web is gripped between drive roll  28  and nip roll  34  by virtue of their friction surfaces. The friction surfaces  30 ,  36  may be continuous or may be formed with a plurality of disk-shaped members such as members  32 . These may be made of any suitable material which provides friction, such as a soft rubber roll or a tracked plastic roll for example. 
     One embodiment includes a vertically oriented press bar assembly  44  (also herein referred to as a “push arm”) with an upper press bar assembly portion  46  mounted pivotably about its upper portion for inward and outward motion with respect to enclosure  14 . Vertically oriented press bar assembly  44  includes at its lower portion  48  a molded-in rack  50  which engages pinion  52  coupled to drive roll  28  by way of a one-way clutch bearing  54  and a driveshaft  56 . Driveshaft  56  is mounted in the clutch bearing  54  which has pinion  52  secured (such as by press-fit for example) thereabout such that the driveshaft  56  advances only when the press bar assembly  44  is being pushed inwardly from its rest position, as will be appreciated from  FIGS. 1 through 4 . The one-way clutch bearing  54  may be a needle clutch bearing. One-way clutch bearings and their application are further discussed in U.S. Pat. No. 4,635,771 to Shoji et al; U.S. Pat. No. 5,655,722 to Muckridge; as well as U.S. Pat. No. 6,336,542 to Mintonye, II, the disclosures of which are hereby incorporated by reference. As used herein the term “lower portion” of the press bar assembly  44  refers to the fact that rack  50  is located toward the lower extremity of the press bar assembly  44  as shown in the drawing. For example, the rack  50  is vertically more than half way toward the bottom of the press bar assembly  44  and alternatively more than about 65% of the distance from top  58  to bottom  60  of the press bar assembly  44  towards its lower portion  48  in order to maximize mechanical advantage. One embodiment includes a unitary support member  62  with the molded-in rack  50  as depicted in  FIG. 4 . Member  62  may include a plurality of tabs  64 ,  66 , for example, to receive a press bar handle  68 . 
     Handle  68  is coupled to the drive roll  28  via press bar assembly  44  and driveshaft  56  such that the drive roll  28  will advance web  42  through dispensing nip  26  upon pivotable motion of press bar assembly  44  about its pivot point indicated at  70 . 
     There is further provided a spring  72  to bias the press bar assembly  44  towards the front of the dispenser  10  such that the press bar assembly  44  projects outwardly therefrom in a rest position as shown in  FIG. 1 . Stated alternatively, spring  72  biases the press bar assembly  44  to its rest position, whereas upon inward motion of the press bar assembly  44 , rack  50  engages pinion  52  and drives drive roll  28  to advance the sheet as will be appreciated from  FIGS. 1 through 4 . Upon outward motion of press bar assembly  44 , rack  50  still engages pinion  52 , however, since bearing  54  is a one-way clutch bearing  54 , pinion  52  is freewheeling and does not turn driveshaft  56 . 
     A dispensing chute  74  located below dispensing nip  26  is provided with a lower arcuate shelf  76  configured to direct web  42  forwardly toward front portion  16  of dispenser  10 . 
     In one embodiment rack  50  is an internal rack configured to engage the pinion  52  along a lower circumferential position  78  with respect to an axis of rotation  80  of the pinion  52 , which is the same as the axis of driveshaft  56 . Accordingly, rack  50  generally has a radius of curvature whose center is on the same side of the rack  50  as the gear teeth thereof. As noted above, clutch bearing  54  may be a one-way needle clutch bearing. An exemplary clutch bearing is Model No. HFZ 640 708E available from INA of Germany. 
     With reference now to  FIGS. 6 through 8 , an embodiment of the dispenser  10  employing an energy storage dispensing mechanism  100  is depicted. The energy storage dispensing mechanism  100  employs an energy storage device  102 , such as a spring for example, to store and transfer energy from the user to dispense a length of sheet from the roll  42  in a controlled manner as will be described further below. It will be appreciated that while the energy storage dispensing mechanism  100  may be described with reference to one embodiment of the dispenser  10 , the scope of the invention is not so limited, and the energy storage dispensing mechanism  100  may be incorporated within other embodiments of sheet product dispensers  10 . 
     In one embodiment, the energy storage dispensing mechanism  100  includes a feed device  104 , such as a feed roller, as part of the foregoing described dispensing nip  26  ( FIG. 3 ), for example. The feed device  104  dispenses a length of sheet product from a supply, such as the roll  42 , to the user. In one embodiment, a user interface  106  is mounted pivotably about an upper portion  108  at pivot  110  and is biased in a first direction  112 , such as to a rest position as shown in  FIG. 6 , by the energy storage device  102 . The user interface  106  is responsive to application of energy from the user to move in a second direction  114  opposite the first direction  112  and to transfer the energy from the user to the energy storage device  102 . The energy storage device  102  is in operable connection with the user interface  106  and the feed device  104  to apply the transferred energy to generate motion of the user interface  106  in the first direction  112  toward the rest position and actuate the feed device  104 , thereby dispensing sheet product from the roll  42 . 
     In one embodiment, the user interface  106  is a vertically oriented push arm assembly and includes at its lower portion  116  a molded-in rack  118  which engages a pinion  120  coupled to the feed device  104  by way of a one-way clutch bearing  122  and a driveshaft  124 . The one-way clutch bearing  122  is secured to pinion  120 , such as via press-fit for example, and is in operable connection with the driveshaft  124 . Upon motion of the user interface  106  in the second direction  114 , such as in response to force applied by the user, the rack  118  engages pinion  120 , however, since one-way clutch bearing  122  is a one-way clutch bearing  122 , the pinion  120  is freewheeling and does not turn the driveshaft  124 . Following such user force to displace the user interface  106  in the second direction  114 , from the rest position, the energy storage device  102  biases the user interface  106  in the first direction  112  back toward the rest position. Such motion of the rack  118 , responsive to the bias force provided by the energy storage device  102  in the first direction  112 , engages the pinion  120  and is transferred via the one-way clutch bearing  122  to rotate the driveshaft  124  (and feed device  104 ) as the user interface  106  moves in the first direction  112 . In one embodiment, the energy storage device  102  is a constant force spring to maintain application of a constant force throughout a range of motion of the user interface  106 . 
     Therefore, the force applied to the feed device  104  and the sheet product is a function of the energy storage device  102  employed, and is independent of the force applied by the user to the user interface  106 . Accordingly, the force, rate of force application, and thus, rate of dispensing speed of the sheet product is consistent, regardless of the force applied by the user to the user interface  106 . Application of consistent force to the feed device  104  is contemplated to increase dispenser  10  reliability and allow use of sheet products that may have reduced strength such as softer, lighter basis weight, or perforated sheets, for example. 
     In one embodiment, the one-way clutch bearing  122  may be a needle clutch bearing as described above. As used herein the term “lower portion” of the user interface  106  refers to the fact that rack  118  is located toward the lower extremity of the user interface  106  as shown in  FIGS. 6 and 8 . For example, the rack  118  is vertically more than half way toward a bottom  126  of the user interface  106  and alternatively more than about 65% of the distance from top  128  to bottom  126  of the user interface  106  towards its lower portion  116  in order to maximize mechanical advantage. An exemplary embodiment of the user interface  106  includes a unitary support member  130  with the molded-in rack  118 , such that material of the upper portion  108  is merged with material of the lower portion  116  as depicted in  FIG. 8 . 
     In one embodiment, rack  118  is an external rack  118  configured to engage the pinion  120  along an upper circumferential position  131  with respect to an axis of rotation  132  of the pinion  120 , which is the same as the axis of driveshaft  124 . For example, rack  118  generally has a radius of curvature whose center (the pivot  110 ) is on the opposite side of the rack  118  as gear teeth  134  thereof, such that the gear teeth  134  point away from the pivot  110 . 
     Referring now to  FIG. 9 , an alternate embodiment of the energy storage dispensing mechanism  100  is depicted. The energy storage device  102  includes a pneumatic storage vessel  136  to store and transfer energy applied by the user. In one embodiment, the pneumatic storage vessel  136  is a pressure containment vessel  136  and is in fluid communication with a cylinder  138  that is sealably disposed surrounding a piston  140  that is in operable communication with the user interface  106 . In response to motion of the user interface  106  in the second direction  114 , the piston  140  is displaced relative to the cylinder  138  and compresses a fluid, such as air for example, within the storage vessel  136  via the cylinder  138 . The energy created by the compression of the fluid within the storage vessel  136  thereby biases the user interface  106  in the first direction  112  toward the rest position to dispense the sheet product as described above. In one embodiment, the energy storage dispensing mechanism  100  further includes a motion rate control  141  (e.g., damper), such as a damper or dashpot for example, to ensure that a velocity of the user interface  106  remains constant throughout its range of motion. For example, the motion rate control  141  may include a cylinder  142  that is sealably disposed surrounding a piston  144  that is in operable communication with the user interface  106 . The cylinder  142  further includes an orifice  146  to control a rate of airflow into and out of the cylinder  142 . In response to motion of the user interface  106  in either of the first direction  112  or the second direction  114  the rate of air flow through the orifice  146  regulates, or dampens a rate of motion of the user interface  106  in either the first direction  112  or the second direction  114 . 
       FIG. 10  (with periodic reference to  FIGS. 6 and 9 ) depicts a flowchart  150  of an exemplary method of dispensing sheet product from a supply to a user. The method begins at  152  with applying mechanical energy to the energy storage device  102  via the user interface  106  that is biased in the first direction  112  to a rest position by the energy storage device  102 . The mechanical energy applied by the user to the user interface  106 , moves the user interface  106  in the second direction  114 , thereby storing the applied energy in the energy storage device  102 . 
     At  154 , the method proceeds with ceasing further application of mechanical energy to the user interface  106 . Therefore, the user interface  106  is permitted to be biased in the first direction  112  under the influence of the stored energy in the energy storage device  102 . In response to the user interface  106  moving in the first direction  112  toward the rest position, the method concludes at  156  with transferring the energy from the energy storage device  102  to the feed device  104  via the user interface  106 , resulting in dispensing of sheet product from the supply  42  to the user. 
     While embodiments of the invention have been described with energy storage devices such as springs and pneumatic storage vessels, it will be appreciated that the scope of the invention is not so limited, and that other energy storage devices to store and transfer energy applied by the user are contemplated as within the scope of the invention, such as flywheels and generator/battery combinations, for example. Further, while an embodiment of the invention has been described and depicted having a vertically oriented user interface that pivots in an inwardly direction relative to the enclosure of dispenser, it will be appreciated that the scope of the invention is not so limited, and that the invention will also apply to other user interfaces that may incorporate other user interface motion and orientation, such as linear motion, which may be oriented horizontally, or may incorporate motions that are parallel to an exterior of the dispenser, for example. 
     As disclosed, some embodiments of the invention may include some of the following advantages: an ability to utilize at least one of softer, lighter basis weight, more absorbent, and pre-perforated sheet product by applying a consistent, appropriate drive force to the towels via the dispensing nip; an ability to increase feed drive component reliability by reducing any force shocks that may be user applied; an ability to meet Americans with Disabilities Act constant compliance since an initial force is set and will not change; and an ability to reduce overall cost of dispenser operation by reducing service requirements. 
     While the invention has been described with reference to exemplary embodiments, it will be understood that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best or only mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. Moreover, the use of the terms first, second, etc. do not denote any order or importance, but rather the terms first, second, etc. are used to distinguish one element from another. Furthermore, the use of the terms a, an, etc. do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.