Patent Application
20080190982
This invention relates generally to dispensers for dispensing sheet material. More particularly, this invention relates to an improved automatic dispenser for dispensing paper towels.
Dispensers for rolls of flexible sheet material, such as paper toweling, have been employed for a great many years. Dispensers are widely used in public lavatories to dispense paper toweling for users to dry their hands. Typically, a roll of sheet material is rotatably supported inside the dispenser cabinet. A user actuates a crank or lever that drives a feed mechanism for dispensing the sheet material. The feed mechanism typically includes a drive roller and an idle roller (or pinch roller). The crank or lever interacts with the drive roller so that actuation of the crank or lever rotates the drive roller. Rotation of the drive roller acts to unwind the sheet material roll. The crank or lever is usually a separate mechanism from the housing of the roll dispenser.
Recently, in order to provide more sanitary conditions and to improve the ease with which roll towel dispensers are used, “hands free” or “touchless” dispensers have been developed. Examples of such dispensers can be seen in U.S. Pat. Nos. 6,820,785, 6,745,927, and 5,772,291. These dispensers eliminate the manually operated crank or lever drive systems in favor of electrically operated drive systems that feed paper with minimal user effort.
In one form, hands free dispensers require a user to wave a hand (or other body part) in front of a sensor mounted in the front of the dispenser. In such constructions, a sensor is generally on or behind the dispenser's front cover. This approach makes the dispenser susceptible to accidental triggering and requires a user to first waive his or her wet hand, then move that or the other hand to the mouth of the dispenser to receive the paper as it's dispensed.
Another form of hands free dispenser starts with a length of paper extending from the dispenser. When the paper is tensioned or a length torn off, the dispenser automatically feeds another length. From a purely ergonomic point of view, this approach is more effective since a user need do nothing other than tear off the previously presented length of paper. However, this approach can be perceived as less sanitary since the length of paper extending from the dispenser prior to use is exposed to the environment for some period of time.
One of the problems with many conventional dispensers is that their configurations permit a user to cause the dispenser to “freewheel” or “free pul” such that an unlimited amount of paper can be pulled. Free pulling is made possible by the angular relationship between the dispenser mouth, the drive and idler roller and the cutting blade. More specifically, where the paper can be pulled in a straight line without contacting the cutting bar, free pulling is possible.
Another problem with conventional dispensers is that paper can jam in the mouth. This can be caused by one or more of a variety of factors including the weight of the paper, the curl of the paper, humidity, ragged edges and static electricity. In general, the narrower the mouth, the greater the likelihood of jamming. On the other hand, if the mouth is made too wide, the ability to free pull increases.
As a general rule, roll sheet material dispensers feed paper downwardly from the bottom of their housings through wide mouths. Some feed the paper straight down while others feed the paper somewhat outwardly as well as down. Depending on the height and placement of the dispenser, this feeding approach actually places the paper in a position that is less than optimal for a user to grasp it, particularly after waving a hand in front of the dispenser's housing. Moreover, the height and width of the mouth of most dispensers is such that when the paper is torn, the edge can get ragged resulting in paper jams and unsightly presentation. This is because there is very little, if any, limitation on the tearing angle that a user can employ to tear off a length of paper and because the size and shape of the mouth causes the ragged edge to catch and twist or fold up on itself. This may also be attributed to safety concerns that limit the sharpness of the blade that can be used. Because the size of the mouth of most dispensers is such that a user's fingers could fit within the housing and contact the blade, its sharpness must be limited.
Accordingly, a need exists for a sheet material dispenser that overcomes some or all of the disadvantages set forth above and provides an improvement over prior art dispensers.
In one embodiment of the present invention, the mouth of a sheet material dispenser is constructed so that the roof of the mouth is essentially eliminated, bringing the dispensing area back to adjacent the point at which the sheet material exits from between the drive roller and idler roller (the “pinch point”). This mouth construction precludes jamming since the paper is available for user access immediately upon exiting from the pinch point. Moreover, since the mouth still retains its floor structure, and since the cutting blade (and trigger arm if the dispenser is an automatic dispenser without a sensor) is positioned so that any outward or upward pull on the paper results in the paper tearing or additional paper being fed in a predetermined manner. No free pulling is possible.
In another embodiment of the present invention a sheet material dispenser is provided that completely changes the paradigm for the presentment of roll sheet material to a user. It does so by providing a “slot mouth” construction that allows dispensed paper to emerge from the dispenser housing upwardly or outwardly, before it moves downwardly.
As noted above, in traditional roll sheet material dispensers, one component of the initial delivery of a sheet material is virtually always down. This embodiment of the present invention alters that convention by essentially “offering” the sheet material to a user by pushing it first upwardly or outwardly before it moves down. This makes a length of sheet material much easier to grasp and is consistent with a more “user-friendly” approach that actually puts the sheet material in a user's hands.
The slot mouth also provides a number of additional advantages. First, because of its visual appearance in the front of the dispenser, the slot mouth provides a user with a visual cue as to where and how to reach for sheet material. Still further, by virtue of its narrow size, the slot mouth “guides” the sheet material from the drive rollers through the slot thereby decreasing the likelihood that the sheet material will roll over on itself and cause a jam. The size of the slot mouth also precludes the possibility of a user using his or her fingers to contact the drive rollers or the cutting blade. As a result, the ability for users to cause jams is reduced because they cannot interfere with the feeding of the sheet material as it leaves the drive rollers. The cutting blade can also be made sharper without fear of user injury, thereby minimizing the possibility of incomplete or uneven tearing of the sheet material and further reducing the chance of jamming. The integrity of the tear is further enhanced because the slot mouth construction effectively limits the angle that the sheet material can take vis-à-vis the cutting bar. More particularly, in order to separate a length of sheet material from the roll, a user must pull the sheet material within a very narrow angular range, relative to the dispenser and/or the cutting bar. For the same reasons, the slot mouth prevents the possibility of a user achieving free pull”. Such action is stopped because there is no way to achieve an angular relationship that would result in free pull without contacting the cutting blade and tearing the sheet material. The avoidance of free pull has a marked impact on the overall consumption of paper because only appropriately measured amounts are dispensed.
The present invention also preferably comprises a sensor that is constructed to minimize power consumption, false triggering, unit cost and is adjustable to achieve various user needs. The present invention preferably provides a means by which the feeding of sheet material can be triggered in a manner consistent with a user's natural tendencies to acquire sheet material from a dispenser. While such a sensor has certain advantages when coupled with the mouth designs of the present invention, it also provides numerous advantages when used in conjunction with more conventional dispensers.
As shown in
As shown in
The drive module 22 comprises an idler roller 30 and a drive roller 32 that, by virtue of their interaction, are capable of selectively advancing sheet material from a roll mounted on support arms 20. The idler roller 30 is mounted between a pair of bearing blocks 34 which rotatably support posts 36 that extend from either side of the idler roller 30. Inside the bearing blocks 34 are springs (not shown) that bias the idler roller 30 to maintain contact with the drive roller 32. The drive roller 32 also has support posts 38 and 40 that extend from its right and left ends, respectively, that are journaled into interior walls of the rear housing 14. Mounted on the end of post 40 of the drive roller 32 is a main drive gear 42. This gear is part of a gear assembly 45 that is used to automatically drive the drive roller 32 and thereby feed sheets of paper. Interacting with main driver gear 42 is a cluster gear 44 that also interacts with an encoder gear 46. The encoder gear 46 is mounted on a shaft 48 that is driven by a motor 50 that selectively supplies the force necessary to turn the drive roller 32.
The motor 50 is driven in accordance with signals conveyed to it from a circuit board 52. Incorporated onto circuit board 52 is some form of controller capable of sending and receiving different signals. One such signal is conveyed to the circuit board by the movement of trigger arm 54 which is rotatably mounted in bearing blocks 34. As trigger arm 54 is moved from a first position to a second position, coincident with the tensioning of paper by a user, trip lever 56 is moved. This, in turn, results in the tensioning of leaf spring 58 that activates switch 60 on the circuit board 52. When trigger arm 54 returns to its first position, the switch 60 is opened and the motor 50 is given a signal to rotate an amount sufficient to feed a predetermined length of sheet material. This predetermined length can be based on a predetermined number of revolutions of the motor shaft, or by using an encoder 62 to measure the length fed in real time.
As shown in
In additional embodiments of the present invention, the power supply for the drive motor and controller can be in the form of a self perpetuating source such as solar cells or static discharge collector. This source can be instead of or supplemental to batteries.
As best seen in
Preferably, the present invention also includes a mechanical cover switch 76 that is used to prevent the drive mechanism from being activated when the front cover 12 is open. More particularly, when the front cover 12 is moved to an open position, by rotating about the center line of hinge 78, the cover switch 76 interacts with trip lever 56 to activate the switch 60 and thereby preclude the activation of the drive mechanism. The configuration of the mechanical switch 76, described herein results in a cost savings over various prior art devices since the electrical switch 60, by virtue of this approach, is able to perform the dual function of precluding activation of the drive mechanism when the cover is open and causing activation of the drive mechanism when the trigger arm 54 completes a cycle from its first position to its second position and back again. A sensor, button or other activation device (not shown) is present so that when the cover of the dispenser is open the drive mechanism can be selectively activated to facilitate paper loading and threading.
In another embodiment of the present invention, a dispenser substantially as shown in
In use, the dispenser of the present invention is first loaded with a roll of paper or other sheet material (not shown). Assuming the housing is closed, this is accomplished by disengaging the latch mechanism 24 and opening the front cover 12 by rotating it about the hinge 78. The roll supports 20 are separated and the roll of sheet material fit thereon. The end of the sheet material is then threaded between the idler roller 30 and the drive roller 32 and the front cover 12 closed. When the cover is closed, a length of sheet material is automatically fed into the throat area 70 and through the slot mouth 18. Preferably that first length of sheet material is then torn off. If the dispenser is operating in trigger arm mode (or is only equipped with a trigger arm), another length of sheet material will be immediately fed as the tensioning and/or tearing of the paper will move the trigger arm from its first position to its second position and back again. When the trigger arm moves to its second position, it acts upon trip lever 56 which, in turn, tensions leaf spring 58. When leaf spring 58 is tensioned, it activates switch 60 on the circuit board 52. Upon release of the trigger arm back to its first (rest position) the switch 60 opens which sends a signal to motor 50 to rotate an amount sufficient to feed a length of sheet material through the slot mouth 18. As motor 50 rotates, the encoder 62 also rotates to measure the amount of sheet material being fed. The motor 50 also rotates encoder gear 46, which in turn, rotates cluster gear 44, which, in turn, rotates driver gear 42. Driver gear 42 is connected to drive roller 32, so that as it rotates, driver roller 32 also rotates thereby forcing sheet material between it and idler roller 30 such that sheet material travels through the throat area 70 and through the slot mouth 18.
In another embodiment of the present invention, shown in
If the dispenser of the various embodiments of the present invention is operating in sensor mode (or is only equipped with a sensor), the tearing of the length of sheet material originally fed when the front cover 12 (or 12a) is closed leaves the dispenser in full operating mode. The dispenser is maintained in this manner until an object is properly sensed by the sensor. Generally, this would be a hand reaching for the slot mouth 18 or wide mouth 18a. At that point, a signal is sent to the controller, which, in turn sends a signal to the motor 50 to begin rotating to feed a length of sheet material. From that point on, the dispensing operation is the same as that described with respect to the trigger arm mode.
Referring to
The sensor 100 operates by detecting and processing reflected light transmitted from a standard IR emitter output in the form of a pulsed carrier wave, preferably but not necessarily a 37 kHz carrier wave. Any commercially available IR emitter may be used in constructing the sensor. However, the IR emitter is preferably a Fairchild QED234 emitter. The IR transmission from the emitter is reflected by an object and detected by a receiver module. The IR receiver module provides all the necessary IR detection and signal processing circuits integrated into one package. Preferably, the receiver module is a consumer remote control receiver module used in common consumer electronic products. These modules are produced by several manufacturers including Lite-On, Vishay, Panasonic, Agilent, Rohm, Sharp and others. The IR receiver module is preferably a Sharp GP1UD262K series receiver module.
When an object enters the sensing area, the sensor is activated. When the sensor is employed in a paper towel dispenser, this configuration provides an intuitive interface between the user and dispenser by anticipating the user's desire to obtain a towel. As the user reaches for the paper towel dispenser, the user's hand enters the sensing area and activates the sensors.
The sensor 100 of the present invention preferably has two states, a quiescent state and an active state. In the quiescent state, the sensor pulses at a rate fast enough to detect an approaching hand, but not fast enough to discern it from noise and minimize false positives and slow enough to reduce the sensor's power consumption. Preferably this pulse rate is between 0.1 milliseconds and 1 second, most preferably approximately 18 milliseconds (ms), although the rate is randomized to reject noise (e.g., fluorescent lights, other washroom sensors) and avoid interference with other identical sensors that may be present in the same facility.
When the sensor, in its quiescent state, detects what may be the presence of hand or other object, it immediately moves to its active state and begins pulsing (sampling) comparatively quickly, preferably between 0.1 milliseconds and 1 second, most preferably on the order of 1-2 ms, in a randomized manner. If the faster pulsing confirms the presence of a proper object within the sensing area, the controller on the circuit board 52 sends a signal causing the motor to turn and feed a length of sheet material. If the faster pulsing fails to confirm the presence of a proper object, for example if someone is walking by and just briefly crosses the active sensing area, the sensor will return to its quiescent state. This particular sensor design, by virtue of its high signal to noise ratio and low power consumption, provides additional advantages over many prior sensors because it doesn't interfere with other sensors that may be present in a given location.
The sensor 100 preferably includes a molded enclosure 106 that at least partially directs and shapes the IR light from the emitter into a desired pattern. (Adjusting the strength of the emitter signal (the field strength) or a lens can be used to assist in shaping the IR light into a desired pattern). The molded enclosure is preferable a polymer material that is preferably both opaque to and absorptive of 940 nm IR light and ambient light. This direction and shaping, coupled with the chosen emitter's inherent directivity characteristics (i.e., relative radiant intensity pattern) and the selective adjustment of power to the emitter, results in a predictable and optimized active sensing area.
However, it is not the emitter alone that defines the sensing area. The IR receiver (or detector) also plays a significant role. More specifically, the detector itself has a detector area or pattern that is inherent in its characteristics. Thus, the area of convergence of the emitter pattern and detector pattern define the ultimate active sensing area. While not generally necessary where the emitter pattern is tightly controlled, the detector pattern can also be shaped by similar means to further define or more tightly control the active sensing area. For example, as shown in
The sensor need not be mounted in the center or the bottom of the dispenser in order to function in accordance with the present invention. In fact, for the dispenser of
The first potential sensor location is on, in or behind the front cover 10 where the cover bulges outwardly to accommodate a roll of sheet material (this location is designated as S1 in
The second and third potential sensor locations are within the throat area 70. Preferably, the emitter and detector would be able to sense directly through the slot mouth 18 or throughout the wide mouth 18a. However, this is not a requirement. It has been determined that the IR sensor of the present invention can function through most appropriate plastic materials used in manufacturing sheet material dispensers, regardless of their visual transparency. Thus, while power requirements may be less if the sensor can function directly through the slot mouth, it is not necessary to achieve the appropriate functionality of the sensor.
Placing the sensor in the throat area 70 also has the potential effect of minimizing the amount of power required for the sensor since the active sensing field is very close to the sensor itself. However, this also means that the sensor must be capable of providing a fairly wide pattern within a very short distance. Within the throat area 70, the dispenser could be mounted in the middle or to the side. As shown in
The fourth potential sensor location is below the slot mouth, either in the throat area 70 or on the bottom of the dispenser 10. In such case, the shaped sensing area would be above and outward from the sensor. There would be no downward component of the emitter or detector fields. The sensing area would extend below, above and in front of the slot mouth 18 or wide mouth 18a.
In all cases, the sensing area is preferably three dimensional. In one preferred embodiment, both the emitter field and the detector field are conical in shape. This renders the convergence or active sensing area as something akin to an elliptical cone, a hyperbolic cone or an asymmetrical elliptical cone, depending on the placement of the sensor with respect to the dispenser. The exact shape and dimensions of the convergence area, however, can be modified by sensor placement, the amount of power applied to the emitter, the shape of the housing used to shape the emitter (or detector) field and the inherent directivity characteristics of the emitter to match the preferred shape of the active sensor area for a given dispenser.
As described above, the sensor is configured as a unit with the detector and emitter located substantially in one location. However, this need not be the case, The emitter and detector can be separated, for example the emitter located in position S1 and the detector located on the bottom the dispenser as described with respect to the fourth potential location. While this configuration increases costs and complexity, the sensing can still be appropriately shaped by the combination of elements described above.
While the sensor and shaped sensing area have principally been described in connection with the dispenser embodiment depicted in
Although the invention has been herein shown and described in what is perceived to be the most practical and preferred embodiments, it is to be understood that the invention is not intended to be limited to the specific embodiments set forth above. Rather, it is recognized that modifications may be made by one of skill in the art of the invention without departing from the spirit or intent of the invention and, therefore, the invention is to be taken as including all reasonable equivalents to the subject matter set forth herein.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2005/047484 | 12/30/2005 | WO | 00 | 11/12/2007 |
| Number | Date | Country | |
|---|---|---|---|
| 60640283 | Dec 2004 | US |
