Abstract:
A singulating and counting device includes a bulk housing for storing a plurality of substantially identical articles, an exit channel, and in the exit channel, forwardly- and rearwardly-directed jet apertures, each of which is fluidly connected to a positive pressure source. A forwardly-directed jet generated by the positive pressure source through the forward jet aperture can accelerate singulated articles in the exit channel, thereby increasing the interval between individual articles and rendering them more easily and accurately counted. A rearwardly-directed jet generated by the positive pressure source through the rearwardly-directed jet aperture can cause articles in the exit channel to return to the housing. A controller operatively connected with the pressure source(s) selectively controls the application of positive pressure to the aforementioned apertures to induce or halt singulation of the articles; the controller may be operatively associated with a sensor that detects and counts articles passing through the exit channel.

Description:
CROSS-REFERENCE TO PROVISIONAL APPLICATION  
       [0001]    This application claims the benefit of Provisional Application Serial No. 60/306,782, filed Jul. 20, 2001 entitled Device to Count and Dispense Articles, the disclosure of which is hereby incorporated herein by reference in its entirety as if set forth fully herein. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    This invention is directed generally to the dispensing of objects, and more particularly to dispensing singulated objects.  
         BACKGROUND OF THE INVENTION  
         [0003]    The problem of counting and dispensing a predetermined quantity from a bulk of small articles exists for a multitude of items and processes. Exemplary items include comestibles such- as candies and breath mints, machine components such as bolts, nuts and other fasteners, valuables such as diamonds and other gemstones, vitamins, and the like.  
           [0004]    The problem has been addressed using multiple approaches. For example, a cavity-filling device sized to physical particulars of a specific article is disclosed in U.S. Pat. No. 3,775,941 to Bross. As another example, a device that counts total weight using a calibrated pieceweight measurement is disclosed in U.S. Pat. No. 4,685,525 to Knothe et al. As an additional example, a device employing a vibratory feeder to singulate (and thus enable counting) is disclosed in U.S. Pat. No. 6,182,718 to Seaton. As yet another example, a device that employs a vacuum to separate and count a fixed, but predetermined number of objects is disclosed in U.S. Pat. No. 6,053,302 to Leu et al. The several devices and techniques exemplified above individually provide varying levels of performance in key operational parameters such as speed, accuracy, universality (adaptability), size, complexity, and cost. But few, if any, provide a high level of measure in more than one or two of the above parameters. Cavity fillers of the type described in Bross are typically bulky and suitable only for articles that closely match the cavity size. Vibratory counters like that disclosed in Seaton are ordinarily bulky and can be difficult to tune (i.e., configure). Weight counters like that described in Knothe can be inaccurate due to piece-weight variability. Vacuum-based systems such as that shown in Leu et al. are typically complex, slow and difficult to calibrate.  
           [0005]    In view of the foregoing, a singulating device which is fast, accurate, small, easy to configure, reliable, and nearly universal would be desirable.  
         SUMMARY OF THE INVENTION  
         [0006]    The present invention is directed to devices and methods for rapidly and accurately counting and dispensing a predetermined quantity of articles from a bulk supply of such articles. The devices include a bulk housing for storing a plurality of substantially identical articles and an exit channel. As a first aspect, a device of the present invention also includes, in the exit channel, a forwardly-directed jet aperture and a rearwardly-directed jet aperture, each of which is fluidly connected to a positive pressure source. A forwardly-directed jet generated by the positive pressure source through the forward jet aperture can accelerate singulated articles in the exit channel, thereby increasing the interval between individual articles and rendering them more easily and accurately counted. A rearwardly-directed jet generated by the positive pressure source through the rearwardly-directed jet aperture can cause articles in the exit channel to return to the housing. A controller operatively connected with the pressure source(s) selectively controls the application of positive pressure to the aforementioned apertures to induce or halt singulation of the articles; the controller may be operatively associated with a sensor that detects and counts articles passing through the exit channel.  
           [0007]    As a second aspect of the invention, a singulating device having a bulk housing and an exit channel includes a jet aperture positioned across the bulk housing from the exit channel. The jet nozzle is fluidly connected with a positive pressure source, which in turn is connected with a controller that selectively controls the application of positive pressure through the jet aperture. This configuration can produce a jet that urges articles in the housing to travel toward the exit channel.  
           [0008]    As a third aspect of the present invention, a singulating device having a bulk housing and an exit channel includes an article-orienting unit that has a pair of panels that, in concert with an upstream portion of the exit channel, define an entry space that permits an oblong or oblate article to enter the exit channel only in a longitudinal orientation in which the longest dimension of the article is generally parallel to a downstream flow path. The upstream ends of the panels extend upstream away from the exit channel and are spaced such that an oblong or oblate article entering the entry space in a transverse orientation in which its longest dimension is generally perpendicular to the downstream flow path that strikes the exit channel?s upstream portion and is re-oriented to the longitudinal orientation in which passage through the exit channel is permitted. In one embodiment, the panels are parallel with one another, and the articles are reoriented when striking either exposed edge of the exit channel upstream portion. In a second embodiment, a third panel perpendicular to the first two panels is included, such that the entry space is generally rectangular. In a third embodiment, the panels are hinged to one another and pivot about a pivot axis that is parallel to the direction of flow, such that the entry space (which is adjustable) is generally triangular. In any of these embodiments, the function of the panels is to orient the objects into a desired attitude for entry into the exit channel.  
           [0009]    In singulating devices with these aspects of the invention, individual articles can enter the exit channel from the housing and travel through the exit channel in single file and with an interval sufficient to allow accurate detection and precise counting of the articles. The pneumatic, reversible nature of the device can enable the handling of a large range of sizes and shapes with a single device configuration. Furthermore, this same feature allows simple adjustments to be applied to handle an even broader range of sizes. The ability to control the various airflows permits the mechanism to be implemented in a volume not significantly larger than a small portion of the bottom of a bulk storage chamber. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    [0010]FIG. 1 is a partial cutaway perspective view of the singulating and counting device of the present invention.  
         [0011]    [0011]FIG. 2 is a schematic side view of the device of FIG. 1.  
         [0012]    [0012]FIG. 3A is a side section view of the device of FIG. 1 showing both the forward jet valve and the rear jet valve closed.  
         [0013]    [0013]FIG. 3B is a side section view of the device of FIG. 1 showing the forward jet valve open and the rear jet valve closed.  
         [0014]    [0014]FIG. 3C is a side section view of the device of FIG. 1 showing the forward jet valve closed and the rear jet valve open.  
         [0015]    FIGS.  4 A- 4 C are front, top and side views of an exemplary article to be singulated with the device of FIG. 1.  
         [0016]    FIGS.  5 A- 5 C are end section views of the article-orienting unit of the device of FIG. 1 showing how the unit admits passage of a properly longitudinally-oriented article (FIG. 5A), prevents passage of a horizontal, transversely-oriented article (FIG. 5B), and re-orients a vertical, transversely-oriented article for proper entry into the exit channel (FIG. 5C).  
         [0017]    [0017]FIGS. 6A and 6B are end section views of an alternative embodiment of an article-orienting unit according to the present invention that enables the size of the opening therein to be adjusted.  
         [0018]    [0018]FIGS. 7A and 7B are end section views of another embodiment of an article-orienting unit according to the present invention.  
         [0019]    [0019]FIG. 8 is a flow chart illustrating a method of singulating articles according to the present invention. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0020]    The present invention will now be described more fully hereinafter, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, like numbers refer to like elements throughout. Thicknesses and dimensions of some components may be exaggerated for clarity.  
         [0021]    Referring now to the drawings, a singulating device, illustrated broadly at  10 , is illustrated in FIGS. 1 and 2. The device  10  includes a bulk article housing  11  in which a plurality of small articles A are suspended in fluidized motion. The housing  11  includes a surrounding wall  12 , a floor  13 , and a ceiling  14 . The wall  12  may be continuous or segmented (i.e., it may comprise multiple contiguous walls), may have a door  12   a  filling for access for articles A and is preferably transparent to allow visual access to the articles A contained therein. Similarly, the floor  13  and ceiling  14  may smoothly merge with the wall  12  or may form distinct corners therewith. Those skilled in this art will recognize that housings of many shapes and configurations may be suitable for use with the present invention.  
         [0022]    In the illustrated embodiment, the floor  13  includes a screen  15  or other foraminous member that allows air passage into the housing  11  but not passage of the articles A out. Similarly, the ceiling  14  includes a screen  16  or other foraminous member that functions to keep articles A in, but allow air passage; in this instance the air flows out of the housing  11 . A blower  17  or other device for inducing airflow is attached to a low pressure plenum  17   a  mounted above the screen  16 . The blower  17  is included to create a negative pressure differential with respect to ambient air pressure by drawing air from outside the housing through the screen  15 , into the cavity of the housing  11 , and out through the screen  16 .  
         [0023]    The illustrated embodiment also includes a jet nozzle  18  or other jet aperture located on the wall  12 . The jet nozzle  18  is oriented to direct a jet into the housing  11  toward an exit channel  20  located opposite the housing from the jet nozzle  18 . Access to the nozzle  18  is controlled by a valve  18   a , which is fluidly attached to a positive pressure source  28  (described in detail below).  
         [0024]    Referring still to FIGS. 1 and 2, at the lower portion of the wall  12 , the exit channel  20  extends away from the housing  11  opposite the jet nozzle  18 . An article-orienting unit  30  is located at the mouth of the exit channel  20  to singulate articles A entering the exit channel  20 . These components are described in detail hereinbelow.  
         [0025]    Referring now to FIGS.  3 A- 3 C, the exit channel  20  includes a primary lumen  21  that extends downstream from the article-orienting unit  30  to terminate at an outlet  22 . The lumen  21  defines a downstream flow path P therein. As used herein, the term “downstream” means the direction that articles A travel in moving from the housing  11  to the outlet  22 . Conversely, the term “upstream” means the direction opposite the downstream direction. It should be noted that, relative to an absolute x-y-z coordinate axis system, these directions may shift as articles A move in the exit channel  20  (for example, in the illustrated embodiment, the articles A move directly away from the housing  11 , then turn downwardly). The “longitudinal” dimension of a structure or component is intended to be parallel with the downstream direction, and the “transverse” dimension of a structure or component is intended to be normal to the downstream direction.  
         [0026]    In the illustrated embodiment, the lumen  21  has a cross-section that permits the passage of only one article at a time; i.e., two or more articles may not travel in the lumen  21  side-by-side. Preferably, the lumen has a cross-section that generally resembles, but is somewhat larger than, that of the transverse cross-section of an article A traveling in the lumen  21 . For example, the lumen  21  of the channel  20  can be sized to be generally rectangular in cross section, with a height or width dimension slightly smaller than two minimum dimensions α of the articles A (see FIGS. 4A and 4C) to prevent the simultaneous passage of two articles A.  
         [0027]    A forward jet pressure chamber  24  and a rear pressure jet chamber  25  are mounted to the exit channel  20 . The forward jet pressure chamber  24  is in fluid communication with the lumen  21  via a pair of forward jet apertures  26   a ,  26   b , each of which is oriented at an angle (preferably between about 1 and 89 degrees, and more preferably between 5 and 50 degrees) relative to the longitudinal axis of the lumen  21  such that a jet exiting the forward jet apertures  26   a ,  26   b  enhances flow in the lumen  21  toward the outlet  22 . The rear pressure jet chamber  25  is in fluid communication with the lumen  21  via a rear jet aperture  27 , which is oriented at an angle (preferably between about 1 and 89 degrees, and more preferably between 5 and 50 degrees) relative to the longitudinal axis of the lumen  21  such that a jet exiting the rear jet aperture  27  impedes flow in lumen  21  toward the outlet  22 . In some embodiments, any or all of the forwardly and rearwardly-directed apertures may be arranged in combinations of any number.  
         [0028]    A common pressure source  28  is attached to each of the forward and rear pressure jet chambers  24 ,  25  and, as noted above, the jet nozzle  18 . The pressure is each chamber  24 ,  25 ,  18  is regulated by a respective valve  29   a ,  29   b ,  18   a . Those skilled in this art will recognize that the pressure in each chamber  24 ,  25 ,  18 , or in fact each jet aperture  26   a ,  26   b ,  27 ,  18 , may be controlled by a separate pressure source. Thus, it is to be understood that when separate “first”, “second”, “third” or even “fourth” pressure sources are described, these pressure sources may be common (i.e., coincident) sources, or any or all of these may be separate sources.  
         [0029]    An article sensor  23  is positioned near the outlet  22  and is configured to count passing articles A as they travel through the lumen  21 . Exemplary sensors include an opposing LED/photo-transistor pair and reflective, capacitive, or mechanical switches. A controller  40  is operatively connected with the valves  29   a ,  29   b ,  18   a  and with the sensor  23 . The controller  40  causes the valves  29   a ,  29   b ,  18   a  to open or close depending on the number of articles A that have been counted by the sensor  23  at any particular point in time. The controller  40  can be any number of controller units known to those skilled in this art as being suitable for receiving signals from the sensor  23  and transmitting operating signals to the valves  29   a ,  29   b ,  18   a ; an exemplary controller is the 87518-bit micro controller, available from Intel,. It should be recognized that the controller  40  may be connected directly to the pressure source  28  (or any other pressure sources in embodiments in which multiple pressure sources are employed) to activate them directly rather than operating the valves.  
         [0030]    Referring now to FIGS.  5 A- 5 C, the article-orienting unit  30  has a pair of generally parallel, spaced panels  31  a,  31   b  and a third panel  32  that is generally perpendicular to the panels  31   a ,  31   b . The downstream ends of these panels  31   a ,  31   b ,  32  abut the mouth of the exit channel  20  and their upstream ends extend slightly upstream into the housing  11 . One skilled in the art will recognize that the downstream ends of one or all of the aforementioned panels may extend most or all the entire length of the lumen  21 , ensuring that only one article A at a time may pass therein. The panels  31   a ,  31   b  are spaced apart a distance a, and the panel  32  is spaced from an upstream portion  20   a  of the exit channel  20  a distance b, thereby defining an entry space E of the dimensions a×b for the articles A. The article-orienting unit  30  is particularly suited for the singulation of articles A that are oblong or oblate, with a longest longitudinal dimension β, a shortest transverse dimension α, and an intermediate transverse dimension δ that is greater than α but less than or equal to β (see FIGS.  4 A- 4 C).  
         [0031]    In one embodiment, the distance a is greater than a but less than the smaller of δ and two times α. In this embodiment, the distance b is greater than δ but less than the smaller of β and two times δ. In this configuration, the articles A can fit in the entry space E in only one orientation (that shown in FIG. 5A, in which the dimension α is generally parallel to the distance a). In another embodiment, the distance a is greater than α and δ, but is less than two times α. In this second embodiment, the distance b is greater than  8  but is less than the smaller of β and two times α. In this configuration, the article A can fit in the entry space E in any orientation in which P is perpendicular to the distances a, b of the entry space E.  
         [0032]    Those skilled in this art will recognize that other configurations for singulating articles may be suitable. The design and dimensions of an alternative article-orienting unit should be chosen to prevent more than one article A entering the exit channel  20  at once. Furthermore, objects whose three dimensions are substantially equal (i.e. spheres) will also pass through the orienting device achieving the desired singulation.  
         [0033]    Exemplary articles include comestibles such as candies and breath mints, machine components sucha as bolts, nuts and other fasteners, valuables such as diamonds and other gemstones, vitamins, and the like. It may also be understood that an article-orienting device may be attached at the outlet  22 , with the result that the device  10  may singulate in both directions.  
         [0034]    In operation, the device  10  begins with the valves  29   a ,  29   b  of the forward and rear jet chambers  24 ,  25  closed (as directed by the controller  40 ), such that the pressure source  28  does not provide jets through the jet apertures  26   a ,  26   b ,  27  or through the jet aperture  18   a  (see FIG. 3A and Block  200  of FIG. 8). The blower  17  is activated and creates a low-level negative pressure with respect to ambient air pressure, causing ambient air to be drawn into the housing  11  through the bottom screen  15  and onto the articles A, thereby suspending (agitating or fluidizing) them.  
         [0035]    The air then passes out through the top screen  16  and past the blower  17 . This agitation gives the articles A fluid flow characteristics within the housing  11  (Block  210 ). The individual articles A travel randomly about the interior of the housing  11 , or can be made to mimic specific fluid flow patterns if desired. In addition, airflow is established from the exterior of the device  10  backward through the exit channel  20 , inward to the housing  11 , and out the top screen  16  to the blower  17 . This airflow pattern prevents articles A from spilling out of the housing  11  into the exit channel  20 .  
         [0036]    Those skilled in this art will recognize that other techniques for preparing articles for singulation may also be employed with the present invention. For example, articles in the housing may be mechanically agitated through known techniques.  
         [0037]    When the controller  40  requests the dispensing and counting of articles, the controller  40  signals the forward jet chamber valve  29   a  to open, and a forwardly-directed air jet is generated through the forward jet apertures  26   a ,  26   b  (see FIG. 3B and Block  220  of FIG. 8). This activity creates a net outward flow of air from the housing  11  through the exit channel  20 . Preferably, the jets apply a pressure of between about 1 and 500 pounds per square inch into the exit channel  20 . One skilled in the art will recognize that a number of different variable pressure control methods may be used for a given pressure pulse through a jet, depending on the effect desired (for example to match the impedance of the object in the channel), including simple square waves, sawtooth, sinusoidal, or complex pressure waveforms. In addition, the controller  40  may signal the valve  18   a  to open so that the jet nozzle  18  emits a jet (preferably of about 1 to 500 psi) that urges articles toward and through the exit channel  20  (Block  230  of FIG. 8). In the case where  26  and  27  are only used a vacuum is induced at the entry space E, with the result that articles A within the influence of this induced airflow are drawn to the article-orienting unit  30 . In the case where only the jet nozzle  18  is used, the high-speed air impinging on the object propels it towards and through the exit channel. Of course one skilled in the art will realize that jets  26  and  18  may be used in concert.  
         [0038]    As the articles A are drawn to the entry space E at the entrance to the exit channel  20 , their orientation determines whether they are able to travel through the article-orienting unit  30 . If an article A is oriented generally parallel to the air flow path with its shortest dimension α generally parallel with dimension a of the entry space E (see FIG. 5A), it is able to fit between the panels  31   a ,  31   b , the panel  32  and the channel wall  20   a  and is, therefore, free to travel into the exit channel  20 . If an article A is oriented perpendicular to the air flow path and generally parallel to panel  32  (see FIG. 5B), it strikes the upstream ends of the panels  31   a ,  31   b  (and therefore cannot enter the exit channel  20 ) and rebounds back into the housing  11  to be further agitated. If an article A is oriented perpendicular to the air flow path and parallel to the panels  31   a ,  31   b  (see FIG. 5C), one end of the article A can strike either the panel  32  or the wall  20   a  of the exit channel  20  (as is illustrated in FIG. 5C). Contact with the panel  32  or of the wall  20   a  causes the article A to rotate about 90 degrees to a position parallel to the air flow path, thereby automatically orienting the article A such that it is free to enter the exit channel  20 .  
         [0039]    Notably, the article-orienting unit  30  is sized and configured so that only one article A can pass through the article-orienting unit  30  at a time. Consequently, articles A enter the exit channel as an endwise (or edgewise), single-file stream.  
         [0040]    Referring now to FIG. 3B, once an article A passes into the exit channel  20  (Block  240  of FIG. 8), the air flow velocity induced by the jet exiting the forward jet aperture  26   a  increases and thus the article A tends to accelerate with that airflow (Block  250  of FIG. 8). Further along the exit channel  20 , the article A encounters that jet directly and so achieves a higher acceleration. Still further downstream in the exit channel  20 , the article A encounters the second jet exiting the forward jet aperture  26   b  and experiences even higher acceleration. Through each of these stages, the interval between successive articles A is increased. Those skilled in the art will recognize that operating with only one forward jet may achieve adequate results.  
         [0041]    As the articles A continue through the exit channel  20 , they pass the sensor  23 , where the articles A are detected and counted (Block  260  of FIG. 8). The increased interval created by the multiple acceleration stages encourages accurate counting of the articles A. Also, the inability of the exit channel  20  to permit the passage of more than one article A at a time at any single point in the exit channel  20  (i.e., the articles A cannot pass “side-by-side” through the exit channel  20 ) also assists the sensor  23  in distinguishing one article A from the next. The sensor  23  signals the controller  40  with the passage of each article A so that the controller  40  can count the number of articles A that have passed thereby and compare that number to a predetermined number (Block  270  of FIG. 8). Those skilled in this art will recognize that, although it is preferred that the sensor  23  be positioned downstream of the forwardly-directed jet apertures  26   a ,  26   b , other locations for the sensor  23  on the exit channel  20  may also be suitable for use with the present invention, and that more than one sensor may be used.  
         [0042]    After the articles A have passed the outlet  22 , they eventually reach a point that they are no longer under the influence of the jet flows or low-pressure flow. They are then free to travel to a receiving container (not shown).  
         [0043]    The process described above continues until the controller  40  determines that a predetermined number of articles has passed the sensor  23 , at which point the controller  40  signals the valve  29   a  to close, which deactivates the forward jets (Block  280  of FIG. 8), and signals the valve  29   b  to open to generate a reverse jet from the rear jet aperture  27  (see FIG. 3C and Block  290  of FIG. 8). The controller  40  also signals the valve  18   a  if present to close in order to cease the production of the jet from the nozzle  18 . The momentum of the articles A that have passed the sensor  23  propels them out of the exit channel  20  and into the receiving container. Articles A that have not yet reached the sensor  23 , however, reverse direction due to the reverse flow created by both the reverse jet and the sub-ambient pressure generated by the blower  17 . Consequently, they return to the housing  11  through the article-orienting unit  30  (aided by the fact that the cross-section of the lumen  21  of the exit channel  20  prevents the articles A from re-orienting). This reversal of direction of the articles A is also assisted by the interval created by the multiple acceleration stages described earlier. In some embodiments, the housing  11  may even be filled with articles A through the outlet  22  via the suction provided by the blower  17  and the rearward jet  27 .  
         [0044]    Another aspect of this invention is that it some instances it may operate adequately without the orienting device. In this case, the controller  40  may be used to detect jams at the entrance to the exit channel (by dint of the lack of passage signals at sensor  23 ) and so the forward and reverse jets may be pulsed off and on to clear the jam. Typically, this is will reduce the overall speed of the system but that may be an acceptable trade in certain applications.  
         [0045]    Those skilled in this art will recognize that other designs for components of the device  10  may be suitable for use with the present invention. For example, the article-orienting unit  30 ′ may take the configuration of that illustrated in FIGS. 7A and 7B, which lacks a plate  32 . Also suitable is the configuration of an article-orienting unit  100  shown in FIGS. 6A and 6B. The article-orienting unit  100  includes a pair of hinged panels  110  that pivot about a pivot axis  111  that is parallel with the flow axis of the exit channel  20 . The hinged panels  110  and the wall  20   a  of the exit channel  20  define an entry space E′ that is generally wedge-shaped and that can, depending on the shape of the article A only permit a single article A to pass therethrough at a time, and to do so in a preferred orientation. One skilled in the art will recognize that the downstream ends of the panels  110  may extend most or all the entire length of the lumen  21 . One advantage of this configuration is the capability of one or both of the panels  110  to pivot relative to one another to adjust the size of the entry space available to the article A, thereby enabling the device  100  to be used on batches of articles that vary in size from batch to batch.  
         [0046]    The foregoing is illustrative of the present invention, and is not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.