Patent Grant
7380748
The present invention relates to dispensers for paper towel rolls and in particular to an improved drive roll to be used in a feed nip typical to such dispensers and an improved dispensing chute tray which has a textured surface to reduce friction between the towel and dispensing chute tray surface.
Paper towel dispensers of the class used for commercial establishments frequently include a drive mechanism for feeding a roll of towel over a cutting blade. A lever or the like is used to advance the towel, while the blade severs a length of towel from a roll when the portion of the towel protruding from a dispensing chute is grasped and removed. The chute/blade geometry is preferably configured to facilitate cutting. To this end, the blade is oftentimes a serrated blade and the feed nip, cutting blade and dispensing apertures of the chute are suitably positioned. Such dispensers are well known. One design which may be employed in connection with the present invention is shown in U.S. Pat. No. DES 417,109 to Johnson et al. The design of the '109 patent includes a generally cylindrically shaped upper portion and a lower, forward facing delivery area for dispensing towel.
It is well known in the art to provide towel dispensers with a dispensing mechanism including a drive roll coupled to a reciprocating operating lever. In this respect there is shown in U.S. Pat. No. 3,606,125 to Tucker et al. a towel dispenser provided with a reciprocating lever. The lever is coupled to a pair of gear racks internal to the dispenser. These gear racks each engage a respective drive gear, one of which is idle during operation, depending on the stroke direction. This action is achieved through a plurality of engagement mechanisms as can be seen in the '125 patent. See also Canadian Patent No. 918,610 and 918,611 also to Tucker et al.
Towel dispensers of the type used in a commercial establishments frequently include those adapted to dispense towels from a primary roll and a reserve roll. These dispensers typically include a rotatable dispensing drive roller and a means for feeding the sheet material from the reserve roll when the primary roll is depleted. In this respect, there is shown in U.S. Pat. No. 4,378,912 to Perrin et al. a dispenser including a rotatable dispensing roller with a groove, sensing means for entering the groove when sheet material from the primary roll is depleted and tucker means responsive to movement of the sensing means to engage the reserve roll of sheet material and introduce it into a nip between rotatable rollers. That is to say, when the primary roll becomes depleted the tucker means will urge material from the reserve roll into the nip between the nip and drive roll to start dispensing from the reserve roll of paper towel. Such towel dispensers may or may not include a push-bar. See, U.S. Pat. No. 5,979,822 to Morand et al.
Despite many advances in the art, drawbacks of existing dispensers include wrinkling and binding of towel during of the dispensing process as well as expense in terms of materials and labor for assembling intricate feed or switching systems. Moreover, existing dispensers tend to have levers and open areas which can lead to microbial contamination of hands after washing or can lead to microbial contamination of towel before it is dispensed. The present invention provides an improved push-bar, low weight drive mechanism which reduces wrinkling. Housing and parts are injection molded to reduce parts and promote a more hygienic enclosure. In further aspects of the invention, the dispensing chute is textured to reduce friction and binding of towel to the chute surface as towel is dispensed. The various improvements of the invention are readily employed in connection with dispensers of the class generally described above.
The present invention relates to towel dispensers of the class shown in U.S. patent application Ser. No. 10/366,120; United States Publication No. 2003/0164079 A1. In one aspect of the invention, there is provided an improved segmented drive roll having an elongate axis and a plurality of drive segments defining drive surfaces disposed along its length of generally equal radius with respect to the elongate axis of the roll, as well as a plurality of guide disks interposed between adjacent drive segments configured to alleviate misfeeding and wrinkling as the towel is dispensed. Generally, the guide disks have an axial span which is less than about 50% if an axial span of any drive segment; typically, the guide disks have an axial span which is less than about 30% if an axial span of any drive segment. So also, the guide disks are preferably of a radius from the elongate axis of the drive roll substantially the same as the radius of the drive surfaces with respect to the elongate axis of the drive roll. While any suitable number of guide disks may be disposed along the shaft, suitably, there are from 2 to 5 guide disks interposed between adjacent drive segments with 3 guide disks interposed between adjacent drive segments shown in the drawings.
In a preferred construction, the drive segments have a substantially cylindrical rigid mounting disk with a support surface and disposed thereabout a band of elastomer material, which elastomer band operates as the drive surface of the drive segment. This drive roll is an injection molded drive roll, wherein the mounting disks with the support surfaces and the guide disks are parts of a unitary injection molded structure; and the guide disks are of a radius which exceeds the radius of the mounting disks by about the thickness of the elastomer band. The injection molded drive roll is injected molded from any suitable injection molding composition; including a molding composition with a polymeric resin selected from the group consisting of ABS resins, polycarbonate resins, polyester resins, polyacetal resins and nylon resins.
In another aspect of the invention there is provided a dispenser for dispensing rolls of paper towel comprising: (a) a housing; (b) means for rotatably mounting rolls of paper towel in the housing; (c) a feed nip including a drive roll and a nip roll adapted to cooperate to advance the towel to a dispensing chute; (d) a cutter bar disposed between the feed nip and the dispensing chute; wherein the dispensing chute is provided with a textured delivery tray surface configured to guide the dispensed towel forward toward a dispensing aperture. The textured delivery tray surface of the dispensing tray is preferably an injection-molded tray surface produced in a textured mold. Suitably, the textured mold has a surface finish at least as rough as an SPI D-2 surface finish; a textured mold with a surface finish at least as rough as an SPI D-3 surface finish is believed more preferred.
The textured surface eliminates the need for unsightly ribs to reduce towel/surface friction on the delivery tray and uses less material making for a more economical and efficient construction of the device; the improvement thus comprising providing the delivery chute with a textured delivery tray surface configured to guide dispensed towel forward over the cutter bar to a dispensing aperture, wherein the textured delivery tray surface has a topography free from projections other than the texture provided thereto. Preferably, the surface of the delivery tray has a texture of less than about 100 microns. “Texture” in quantitative terms referring to the maximum distance that surface features project from their base over the surface of the dispensing tray.
In another aspect of the invention there is provided a method of dispensing paper towel from a primary feed roll and a partially depleted stub roll comprising: (a) providing a towel dispenser with housing, an elevated mounting rack for rotatably mounting a primary feed towel roll, a stub roll cavity below the elevated towel mounting rack and drive means for advancing paper towel from the rolls to a dispensing chute, the drive means consisting of: a feed nip with (i) a drive roll and (ii) a nip roll as well as (iii) means for rotating the drive and nip rolls; (b) rotatably mounting a primary feed paper towel roll on the elevated mounting rack; (c) concurrently with step (b), disposing a partially depleted stub roll in the stub roll cavity below the primary feed roll; (d) concurrently with steps (b) and (c), providing towel from both the primary feed roll and the stub roll into the feed nip such that towel from both the primary feed roll and the stub roll are advanced when the drive and nip rolls are rotated in a dispensing direction; and (e) simultaneously dispensing towel from both the primary feed roll and the stub roll through the feed nip.
The inventive method eliminates the need for complex internal assemblies for switching from one roll to another.
Further features and advantages will become apparent from the discussion which follows.
The invention is described in detail below in connection with the various Figures wherein like numerals indicate like parts and wherein:
The invention is described in detail below in connection with the various figures. Such description and illustration is for purposes of exemplification only; modifications within the spirit and scope of the present invention, set forth in the appended claims, will be readily apparent to those of skill in the art.
Referring to
In order to evaluate towel inventory, there is provided a sight glass 32 on the front of cover 14 so that a technician can observe the amount of towel remaining on a feed roll 25.
Paper towel is fed to a feed nip 36 which includes a drive roll 38 as well as a nip roll 40 which feeds towel 25 over a cutter bar 34. Drive roll 38 is mounted on a drive shaft 42 which has a pinion 44 preferably mounted on a one way bearing at 46. A push bar assembly 48 has a drive member 50 with an integrally formed rack 52 for driving pinion 44 and operating the dispenser. The push bar assembly 48 also has push bar plate 54 which preferably has a baffle 56 which helps maintain slot 58 in a closed or shielded position even when the push bar is retracted into slot 58 when pushed to dispense towel. In other words, baffle 56 is configured to substantially seal slot 58 even when the push bar is pushed inwardly to drive roll 38 and dispense more towel.
There is further provided a dispensing chute module 60 having a tray 62 provided with a textured tray surface 64. As noted above surface 64 is preferably provided with a textured surface having a surface roughness corresponding to that of an SPI D-3 finish.
Preferably, all parts are injection molded for efficient fabrication and in order to make the enclosure hygienic; that is, to substantially isolate the interior of the dispenser from its surroundings. Also, push bar assembly 48 may be pushed inwardly without using fingers or hands, if so desired. A user may use a forearm or other means to activate the dispenser. Injection molding allows for modular construction as is appreciated perhaps best by reference to
The improved drive roll 38 of the present invention is perhaps better understood by reference to
Prior art drive roll 78 is a segmented drive roll having a plurality of spaced drive surfaces 80, 82, 84 and 86. The drive surfaces are spaced apart on a shaft 90. It will be appreciated from the various diagrams that there is a gap between the drive surfaces and central shaft 90 which leads to towel wrinkling or misfeeding of the product.
A drive roller of the invention is shown in
Each guide disc has an axial span 124 which is much less than the axial span 126 of the drive segments.
It is further noted that the drive segments include an elastomer band such as bands 128, 130, 132 and 134 mounted on a substantially cylindrical rigid mounting disc such as discs 136, 138, 140 and 142. The mounting discs are much broader, that is, have much more axial span than the elastomer bands 128 through 134. The elastomer bands define the drive surfaces in a preferred embodiment shown in the various Figures.
Preferably, drive roll 38 is fabricated by injection molding and is dimensioned such that the drive surfaces 100 through 106 are of generally equal radius with respect to an elongate axis 144 of the drive roll. In a particularly preferred embodiment, the guide discs are of a radius such as radius 146 which exceeds the radius such as radius 148 of the mounting discs by about the thickness of the elastomer bands 128 through 134 such that the guide surfaces of the discs and the drive surfaces of the drive segments are of substantially equal radius with respect to elongate axis 144 of the drive roll.
A further salient feature of the present invention is a textured chute as noted above. Particularly important is textured tray surface 64 which prevents or alleviates frictional binding of towel from roll 25 to the delay surface. This feature promotes smooth delivery of product.
A still further aspect of the invention is a novel method of simultaneously feeding product from a fresh feed roll such as roll 25 and a stub roll such as roll 125.
To this end, roll 25 is mounted on towel rack 24 of dispenser 10. At the same time, a partially depleted or stub roll is disposed in a stub roll cavity 130 of the dispenser. Towel 25 is fed into feed nip 36 together with towel 125 such that towel from both rolls is fed through the nip as shown in
The towel dispenser has drive means consisting of feed nip 36 which has a drive roll and a nip roll as well as means for rotating the drive and nip rolls. This configuration eliminates the need for complex apparatus and mechanisms for switching feed from one roll to another. Also, the towel from stub roll 125 is not discarded but fed with towel 25 to a consumer.
While the invention has been described in connection with several examples, modifications to these examples within the spirit and scope of the invention will be readily apparent to those of skill in the art. In view of the foregoing discussion, relevant knowledge in the art and references discussed above in connection with the Background, Summary of Invention and Detailed Description, the disclosures of which are all incorporated herein by reference, further description is deemed unnecessary.
This non-provisional application is based upon U.S. Provisional Patent Application Ser. No. 60/635,788 filed on Dec. 14, 2004, of the same title. The priority of U.S. Provisional Patent Application Ser. No. 60/635,788 is hereby claimed and the disclosure thereof is incorporated into this application by reference.
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| Number | Date | Country |
|---|---|---|
| 918610 | Jan 1973 | CA |
| 918611 | Jan 1973 | CA |
| 0 319 166 | Jun 1989 | EP |
| Number | Date | Country | |
|---|---|---|---|
| 20060138274 A1 | Jun 2006 | US |
| Number | Date | Country | |
|---|---|---|---|
| 60635788 | Dec 2004 | US |
