DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0031] Referring to FIG. 1, the rolled tissue dispensing device 10 is comprised of an exterior housing 12 having a front face 11, a back face 15, and two lateral faces 13. A top cover 14, attached to the exterior housing 12 along the top edge of the back face 15 by hinge 16, provides access for the top loading of replacement tissue rolls 30. A bottom dispensing tray 18 provides the dispensing medium for users, and an opening 20 in the tray 18 facilitates the removal of a pile of tissue sheets. A lower cutout 17 in the vertical front face 11 of the housing 12, provides frontal access to the tissue sheets for the user. The front face 11 of the casing 12 also comprises an out-of-paper indicator light 26 and a load-paper push button 28. A selector switch 24 which permits the pre-selection of the number of tissue sheets desired, and a power switch 22 are located on a lateral face 13 of the exterior housing 12.

[0032] Referring now to FIG. 2, the device uses two sets of rollers, namely, feed rollers 32 and 34 and tearing rollers 40 and 42, to pull the tissue from the feed roll 30. Roller 32 is driven by a motor 48 through a belt 38. The motor 48 is also used to drive tearing roller 40, through an adjustable clutch 44 having a free pulley 41, by belt 46. Rollers 34 and 42 are held in contact with rollers 32 and 40 respectively, by helical coil compression springs 54 and 56 mounted on fixed bases 58. The springs ensure contact with driven rollers 32 and 40 causing spring-loaded rollers 34 and 42 to rotate in opposite directions from rollers 32 and 40. The spring-loaded rollers 34 and 42 apply pressure to the paper, however still allowing small foreign objects which may fall inside the housing, such as coins, to pass through without obstructing the system. The size of the pulleys are chosen such that rollers 40 and 42 rotate faster than rollers 32 and 34.

[0033] An optional additional feed roller 36 provides additional support and rotating force for the tissue roll 30. Small guide rollers 50 on either side of the tissue feed roll 30 ensure that the tissue roll 30 is centered and does not translate forward when it is rotated by the feed rollers 32 and 36. Alternate feed roller 36 is driven by the attached pulley 37 which is driven by the motor 48 through a belt 39. The motor pulley 51 is the driver for the belt driven roller pulleys 33, 37, and 41.

[0034] The entire roller support assembly 52 is fixed to the inside of the lateral faces 13 of the housing 12. The sheet paper guide 60, as shown in FIG. 4, is downwardly biased towards the rear face 15 of the exterior housing 12. The curved upper portion 62 of the sheet paper guide 60, accepts tissue sheets pushed into the guide by tearing rollers 40 and 42. Paper sheets then slide down the top surface of the guide 63. To ensure that the paper sheets slide down the guide smoothly, the guide can be coated with a material such as Teflon. At the upper portion of the guide, the individual tissue sheets are supported by the top surface 63 such that the sheets remain generally flat as they slide down the guide. Trapezoidal shaped cutout 66, in the middle of the guide 60, eliminates the center support for the descending tissue as it reaches the lower portion of the guide. This causes the tissue sheet to cave in the middle, and fall through the guide into the dispensing tray 18 below. An opening 64 in the upper curved portion 62 of the sheet paper guide 60, allows for the number of sheets dispensed to be counted by a censor. The device uses two photocell detectors 68 and 72 which have corresponding reflecting mirrors 70 and 74 respectively. Photocell detector 68 monitors the number of tissue sheets torn from the roll. Photocell detector 72 monitors the presence of paper in the dispensing tray 18.

[0035] When a roll of tissue 30 is inserted into the space 31 above the rollers, such that gravity maintains contact between the paper roll and the rollers, and the load button 28 on the front face 11 of the exterior housing 12 is pushed, the rollers 32 and 36 begin turning and rotate the roll of paper tissue 30. As the freed end of the paper roll reaches feed rollers 32 and 34, the loose end will get caught between feed rollers which pull the continuous tissue strip 19 down through the paper guide 25, feeding the end into tearing rollers 40 and 42. As rollers 40 and 42 are spinning faster than feed rollers 32 and 34, the clutch 44 on roller 40 will begin to slip. The difference in rotating speeds between the lower rollers 40 and 42 and the upper rollers 32 and 34 creates pressure on the tissue strip between the two sets of rollers. The clutch 44 is adjusted so that the pressure on the tissue is such that it does not break the non-perforated tissue. However, when a perforated line in the tissue strip comes between the upper and lower sets of rollers, the tissue strip will break. The now separated individual tissue sheet 21 is pushed down into the tissue sheet guide 60 under the tearing rollers 40 and 42, and subsequently falls into the dispensing tray 18 below. The system would equally work if rollers 32 and 34 were driven through the clutch and rollers 40 and 42 were driven directly by the motor. However, the roll of paper 30 would subsequently rotate in a less smooth and continuous manner.

[0036] FIG. 10 shows the individual elements of the adjustable clutch 44. The driven tearing roller 40 rotates about an axial shaft 55, and is located by a support bearing 53. Drive disk 43 is fixed on the shaft 55 by a keyway 57. A free clutch pulley 41 is driven by the electric motor 48 through a drive belt 46. The clutch pulley 43 is held against the drive disk 43 by a clutch helical coil compression spring 47, and a retaining nut 49 is threaded onto the shaft 55. By tightening or loosening the retaining nut 49, the spring will exert more or less force on the clutch pulley 41. This allows the amount of slip of the clutch to be varied, and therefore permits calibration of the force applied by the tearing rollers on the tissue.

[0037] An alternate embodiment of the present invention, shown in FIG. 3, comprises two independent electric motors, namely, existing motor 48 and additional motor 76. No clutch is required in this embodiment, as motor 48 drives feed rollers 32 and 36, and the additional motor 76 drives the tearing roller 40. The additional motor 76, however, is driven with a higher voltage than the first motor 48. This difference in voltages translates directly into a difference in torques. Therefore, the motor 76, having more torque than the first motor 48, would apply a greater downward pressure on the paper tissue, thereby tearing off tissue sheets from the continuous roll. The voltage difference for the alternate motor 76 is calibrated in a manner similar to the variable clutch 44 in the first embodiment. The voltage difference is set to a value such that if there is no perforated line in the tissue paper between the two sets of rollers, the tissue strip will not break. However, when a perforated line in the tissue strip appears between the two sets of rollers, the tissue will tear along these perforations. A sufficient discharge speed of the torn-off tissue sheets is required in order to guarantee that the tissue sheets 21 will fall through the trapezoidal cutout 66 in the guide 60 and settle in the dispensing tray 18 before the next sheet arrives. This guarantees that the individual tissue sheets 21 are stacked neatly on top of each other.

[0038] The user can select the number of sheets desired in the dispensed stack by presetting the sheet selector switch 24 on the lateral face 13 of the exterior housing 12, which varies the subsequent thickness of the tissue sheet pile. As each individual torn-off tissue sheet 21 is discharged from the tearing rollers 40 and 42, the photocell detector 68 senses each sheet of paper as it passes through the light beam of the detector. An electronic control system 97, as shown in FIG. 11, receives the input of the photocell detector 68 and compares the number of sheets that have passed by the detector 68 to the value preset by the user with the selector switch 24. When these two numbers are equal, the drive motor is stopped by the control system 97. When the photo detector 72 senses that the pile of sheets in the dispensing tray 18 has been removed, the motor is activated, and the cycle restarts delivering another pile of sheets into the dispensing tray. When the load paper button 28 on the exterior of the casing 12 is pushed, the motor is similarly started and runs until the preset number of individual tissue sheets have been dispensed into the tray. If the photocell detector 68 fails to sense paper for a preset time period, the motor will automatically stop, and the out-of-paper indicator 26 on the exterior of the casing 12 will light up.

[0039] Although the system has been designed for toilet paper use, the device could be equally used in other applications requiring larger systems, such as paper toweling or sheet paper production. Similarly, this system could replace boxed facial tissue when used in commercial establishments. Additional features which would prevent the abuse of the device can be easily introduced through the control system 97, such as fixing a maximum number of tissue sheets which can be dispensed at one time, and presetting a delay time before subsequent tissue sheets are dispensed following the removal of a stack of tissue sheets.

[0040] FIG. 5 shows an alternate embodiment of the tissue dispensing device. A double dispenser system 78 comprises a double system exterior housing 80 enclosing two individual tissue dispensing devices 10, as previously described. This system solves the problem associated with a single roll dispensing device running out of paper. Such a double dispenser system is necessary for commercial uses. Commercial establishments, such as restaurants and hotels, are reluctant to leave partially used rolls in the roll dispensing holders in the event that a partial roll will not be sufficient. Full spare rolls left unattended can be stolen or incorrectly inserted into the dispenser by the user. Dispenser holders which stack one roll above the other are not ideal, as the stacked rolls impede the bottom dispensing roll from turning. Two individual rolls side by side do not adequately solve the problem either, as there is no way to ensure that users will use the smallest roll first. This increases the likelihood that two partially used rolls will remain. Attendants then have to replace the partially used rolls with full ones in order to ensure a sufficient quantity is supplied. A solution is to use two identical dispensing systems in one single enclosure with an electronic switch-over from one system to another when the smallest roll is completely used up. In this way, there is also a backup system should one fail. Two additional photocell detectors 82 are provided on the interior wall 81 of the double system housing 80. Corresponding reflecting mirrors 84 on the interior of the lateral faces 83 of the housing 80 reflect back the light beam from the photocell detectors when a paper roll is empty. When a photocell detector 82 senses that one roll is used beyond a preset level, the system automatically dispenses paper from the smallest roll, making sure that the roll will be completely finished before switching to the fuller roll.

[0041] FIG. 6 shows an alternate embodiment of the tearing rollers 40 and 42. In this embodiment, rollers 86 and 88 are formed having an interfitting wavy profile, which gives the paper passed through the rollers added rigidity. This prevents tissue sheets from them curling backwards as they slide down the tissue sheet guide 60.

[0042] Another embodiment of the present invention is shown in FIG. 7. One potential problem with the device is that a paper roll which is not correctly inserted or which for some other reason moves laterally as it is pulled through rollers 32 and 34, can become jammed. A solution to this problem, as shown in this embodiment, is to replace one or both feed rollers 32 and 34 having a uniform circumferential surface, with rollers 94 and 96 which have a double-convex longitudinal profile such that they are generally cylindrical but have a circular cross-section which gradually decreases towards the ends of the roller. Additionally, two control system activated solenoids 90 and 92 can provide slight rotation of the rollers about a vertical central axis through roller lever arms 91 or 93.

[0043] Two additional sensors, a left photocell 102 with corresponding light emitting diode 104 and a right photocell 106 with corresponding light emitting diode 108, are positioned on opposing ends of the sensing and serrating assembly 110, such that they are located on either side of the descending tissue strip 19. If the continuous tissue strip wanders too far to one side, the photocell on the corresponding side will sense the presence of the tissue, and the control system will activate the opposing solenoid side in order to recenter the tissue strip. The curve of the rollers 94 and 96, and their relative rotation when the solenoids are activated, will re-align the off center tissue strip. FIG. 8a shows such a system in normal operation.

[0044] FIG. 8b shows the case where the tissue strip has moved laterally to the left in the drawing, and the rollers are squeezed together on the opposite side, creating a pulling center to the right side of the tissue strip, thereby recentering the strip. FIG. 8c shows the same situation, but for a strip that has strayed to the opposite side of center. Activating both solenoids simultaneously, as shown in FIG. 8d, permits the rollers to be completely removed from contact with each other. This removes the pressure put on the tissue strip and allows the strip to pass through the device without being broken. This permits a continuous sheet to be delivered if desired. The tissue feed slot 109, between the opposing halves of the sensing and serrating assembly 110, helps guide the descending tissue strip between the sets of rollers.

[0045] For certain applications, the rolled tissue may not be preperforated into individual sheets. The embodiment shown in FIG. 7 permits the serration of such a tissue roll. A comb-like serrator assembly 111 comprises a serrator base 114, serrator blades 116, and a dedicated solenoid 112. Corresponding holes 117 for the serrator blades 116 are located in the opposing half of the sensing and serrating assembly 110, as shown in FIGS. 7 and 9. When the serrator is activated by the solenoid 112, the sharp edges of the serrator blades are pushed through the stretched paper tissue, causing it to break. A control system, as shown in FIG. 11, detects if the inserted roll of tissue is non-perforated and switches automatically to the program for providing serrations using the serrator assembly 111. This allows the use of both perforated and non-perforated tissue.

[0046] The embodiment(s) of the invention described above is(are) intended to be exemplary only. The scope of the invention is therefore intended to be limited solely by the scope of the appended claims.