Abstract:
A method for storing and dispensing thin, flimsy objects such as end disks that form the ends of light-tight packages for photosensitive materials. The thin, flimsy objects are loaded onto a hub member and supported by a biased pusher plate that urges the objects one at a time through a stripper plate that has a removed section slightly smaller in dimensions than the object.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is related to U.S. application Ser. No. 09/430,449, filed Oct. 29, 1999, by John A. Spina, et al., and entitled, “An Article Of Manufacture For Storing And Dispensing An Object;” and U.S. application Ser. No. 09/430,582, filed Oct. 29, 1999, by John A. Spina, et al., and entitled, “Cassette And Method For Storing And Dispensing Objects Arranged In A Stack.” 
    
    
     FIELD OF THE INVENTION 
     The invention relates generally to a method of storing and dispensing thin, flimsy objects. More particular, the invention relates to a method of storing and dispensing objects such as end disks suitable for forming the ends of light-tight packages. 
     BACKGROUND OF THE INVENTION 
     Currently rolls of photographic film and paper are packaged in several different ways to facilitate room light loading into cooperating apparatus which dispenses or otherwise uses the film or paper. Commonly assigned U.S. Pat. Nos. 4,148,395 (Apr. 10, 1979, by Syracuse et al., and entitled “Roll Package”) and 5,515,970 (May 14, 1996, by Ritchie et al., and entitled “Light-Tight Package”) each discloses a package which includes a pair of flexible opaque end disks or covers attached to the ends of the core of the roll and an attached leader attached to the leading end of the length of film or paper forming the roll. A peripheral portion of each disk is folded over and adhered to the edge of an underlying convolution of the leader. 
     Commonly assigned U.S. Pat. No. 5,133,171 (Jul. 28, 1992, by Chase et al., and entitled “Light-Tight Packaging Method For Photosensitive Web Roll”) discloses a package that includes a pair of similar end disks and a leader. After a first convolution of the leader is wrapped onto the roll, peripheral portions of the end disks are folded over the first convolution. A second convolution is then wrapped onto the roll to capture the folded-over peripheral portions between the first and second convolutions and to make the package light-tight. 
     An existing practice for installing end disks on light-tight packages of the sort described above include manually grasping an end disk from a stack and then fastening it to the ends of the core. Another practice includes using a vacuum suction device to pick out a single end disk and then transfer it to the core of the roll. Each of the above practices, however, has numerous shortcomings that the present invention solves. In particular, an operator will invariable damage thin, flimsy, end disks when handling them manually. Moreover, multiple end disks are dispensed although only one is intended. 
     Although not particularly related to the problem encountered by the inventors, U.S. Pat. No. 4,199,076 (Apr. 22, 1980, by Brown and entitled, “Cup Dispenser”) discloses a dispenser of cups that has a slidable plate for supporting a stack of cups and an end plate having a cavity through which the cups are dispensed one at a time. The patent does not provide means for storing and dispensing thin, substantially flat objects. 
     Therefore a need persists in the art for a method of storing and dispensing thin flimsy objects that is simple to use, protects the fragile objects from damage and is cost effective to manufacture. 
     SUMMARY OF THE INVENTION 
     It is, therefore, an object of the invention to provide a method for storing and dispensing a plurality of thin flimsy objects. 
     It is another object of the invention to provide a method for storing and dispensing thin flimsy objects that can dispense a single object without affecting the next adjacent object in the stack. 
     The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, a method of storing and dispensing thin, flimsy objects each having a first, removed concentric section, a loading side and an opposed active side, said method comprising the steps of: 
     providing a cassette having a base member, a hub member arranged centrally in the base member, a pusher plate arranged on said cassette for supporting a portion of one of said thin flimsy objects arranged in a stack, a stripper plate having a removed section for relieving a top most thin flimsy object from said cassette, and a source of air for separating said top most thin flimsy object from a nearest adjacent thin flimsy object; 
     mounting said thin flimsy objects onto said hub member with the loading side of one object in contact with he unloading side of the nearest adjacent object arranged in the stack; and, 
     directing a burst of air to said loading side of said top most object and to the unloading side of said nearest adjacent object for relieving said top most object from said hub and then through said removed section of said stripper plate. 
     The advantages of the method of present invention include it&#39;s simplicity, ease of removing a object, elimination of damage to features of the thin flimsy object upon removal, such as interior diameter, and it is easily adaptable to various materials. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other objects, features, and advantages of the present invention will become more apparent when taken in conjunction with the following description and drawings wherein identical reference numerals have been used, where possible, to designate identical features that are common to the figures, and wherein: 
     FIG. 1 is a schematic perspective, exploded view of a light-tight package having two unattached end disks; 
     FIG. 2 is side elevation view, partially sectioned, of the cassette of the invention; 
     FIG. 3 is a front elevational view of the cassette of the invention; 
     FIG. 4 is a perspective view, of the cassette tilted on a side; and 
     FIG. 5 is a perspective view of the cassette as shown in FIG. 4 tilted on an opposing side. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The invention will now be described with respect to various embodiments thereof. Turning now to the drawings, and in particular to FIGS. 2-5, a storage and dispensing cassette  10  for objects, such as end disks  12  (shown in FIG.  1 ), arranged in a stack  14  is illustrated. Cassette  10  is suitable for use to store and dispense various sizes of end disks  12  (described below). The end disks  12 , generally arranged in a stack  14  in cassette  10 , are positioned to be picked from the cassette  10  via vacuum source (not shown) or similar methods, indexed to the pick position, and then dispensed one at a time from the cassette  10 . According to FIG. 1, the objects or end disks  12  are suitable for use in a light-tight package  16  (FIG.  1 ). When properly arranged on the core of the roll of light sensitive web  17 , a pair of identical end disks  12  blocks light passage to the light sensitive web  17 . As seen in FIG. 1, end disks  12  have a first concentric section  18 , a loading side  20  and an opposed unloading side  22 . Moreover, end disks  12  are of flat materials made of generally plastic, foil, and paper laminates or extrusions with thickness from 0.003 inches to 0.010 inches. The form of the end disk  12  is generally one of circular shape with a removed concentric section  18 . 
     Referring to FIG. 2, cassette  10  has a body  24  (clearly shown in FIG. 4) having a base plate  26  and a plurality of spaced, upright, outwardly extending standoffs  28  fixedly attached at one end to the base plate  26 . 
     Referring again to FIG. 2, a hub member  30  is arranged substantially centered in the base plate  26  and extends outwardly therefrom. The hub member  30  has a diameter slightly smaller than the first, removed concentric section  18  of any one of said plurality of objects or end disks  12  to be stored thereon. 
     As illustrated in FIGS. 2-5, a biased pusher plate  32  supports at least a portion of the loading side  20  (as shown in FIG. 1) of one of the plurality of objects or end disks  12  arranged about the hub member  30 . The biased pusher plate  32  is biased preferably by spring  34  fixed against the base plate  26  and is slidable substantially in a plane substantially parallel to the base plate  26 . The spring  34  is sized such that it is strong enough to push the stack  14  of end disks  12  as each is removed, but not too forceful to interfere with the removing of single end disks  12 . With the material tested, a force between 1 lb. and 4 lbs. was acceptable. Other devices in place of springs could be used such as an air cylinder or a hydraulic cylinder which could apply constant force. Biased pusher plate  26  rides on bearings  11  and is slidable from a first position absent of supporting an object or end disk  12  thereon, to a second position supporting at least one of the objects or end disks mounted on the hub member  30 . The outside diameter of the pusher plate  32  is preferably larger than the removed section  38  of the stripper plate  36  (described below), for it might push the last few end disks  12  through the second, removed concentric section  38  if it were smaller. 
     Referring now to FIGS. 3 and 4, a stripper plate  36  has a removed section  38  and a continuous edge  40  surrounding the removed section  38 . It is important to our invention that second concentric section  38  has a diameter at least slightly smaller than the diameter of the end disks  12  for securing a top most object or end disk  12   t  on the hub member  30 . Clearly shown in FIG. 2, stripper plate  36  is supported on an end  44  of the outwardly extending standoffs  28  for receiving and relieving the end disks  12  through the second concentric section  38 . 
     As indicated above, the removed section  38  of stripper plate  36  has a diameter smaller than the diameter of the removed concentric section  18  of end disks  12  so that the end disks  12  are retained but can be removed without permanently distorting the end disk material. As the air blast (described below) is applied, a smaller diameter of removed concentric section  38  in stripper plate  36  would be desired. Relief pockets  37  can be cut into the stripper plate  36  opening to allow the material to escape easier with less deformation also allowing the second, removed concentric section  38  of stripper plate  36  to be even smaller. To avoid forcing end disks  12  out the second, removed concentric section  38  from the force of the air blast (described below), the relief pockets  37  must not expose the outer surface (OD) of the end disk  12 . The relief pockets  37  could be of various shapes, such as rectangular, square, triangular, and circular. 
     Referring to FIGS. 2,  4 , and  5 , a source of air  48  is structurally associated with the body  24  of cassette  10 , for instance base plate  26 . The source of air  48  has an air nozzle  50  directed between the loading side  20  of the top most end disk  12   TM  and the unloading side  22  of the nearest adjacent end disk  12   NA . A stream of air from air nozzle  50  causes the top most end disk  12   TM  to lift from the hub member  30  through the second concentric section  38  of the stripper plate  36 . More particularly, the air nozzle  50  is positioned such that the air is directed in a manner to separate the leading (the end disk being dispensed) and the trailing disk, allowing the leading end disk to be removed without also removing or even partially removing the trailing end disk. The air nozzle  50  may be directed perpendicular to the stack  14  of end disks  12  as long as only one end disk  12  is removed. It also could be directed at some angle (i.e. 45 degrees) along the stripper plate  36  back face such that the air flow would travel along the stripper plate  36  face creating the desired state mentioned above. The position of the air nozzle  50  relative to the stack of end disks  12  should be in an area where air is allowed to pass between the two end disks  12 , but not where the vacuum suction cups (not shown) are applying force. The end disks  12  must be able to move or separate relative to each other. The pressure of the air must be great enough to force the materials away from each other but not so great as to force the end disks  12  through the second, removed concentric section  38  of stripper plate  36 . The setting would depend on material characteristics of the end disk  12  (i.e. flexibility). For instance, we tested an end disk  12  having a laminate structure comprising HDPE. It was determined that a pressure between about 30 psi and about 60 psi could be used to separate adjacent end disks  12  in a stack  14 . Moreover, the amount of overlap of the removed section  38  of stripper plate  36  as well as the relief pockets  37  in the stripper plate  36  relative to the OD of the end disk  12  have some bearing on air pressure setting. 
     In operation, the end disks  12  are loaded onto the cylindrical end disk hub  30  about the removed concentric section  18  of the end disk  12 . The end disks  12  are retained between the stripper plate  36  and the pusher plate  32  via pressure from pusher plate  32  spring  34 . The pusher plate  32  and pusher plate bearing  11  index the end disks  12  to the pick position as each end disk  12  is removed. An air nozzle  50  supplies a blast of air that separates the ends as each end disk  12  is pulled through the stripper plate  36  and removed from the cassette  10 . The air nozzle  50  is positioned such that it directs air in such a way to separate the leading and the lagging end disk  12 . The removed section  38  in the stripper plate  36  is circular in shape and is slightly smaller in diameter than the end disk  12  outside diameter. The stripper plate  36  also has four relief pockets  37  to allow the end disk  12  to be pulled through without creasing the material as shown in FIG.  2 . 
     When removing flexible materials it is desired to pick the material at three or four locations along the surface. A circular groove or ring (not shown) could also be used which would have 360 degrees of hold. It was found that pulling the material out of the removed section  38  of stripper plate  36  at a slight angle was beneficial as it peeled the material out versus pulling the entire surface out at once. This was accomplished using four vacuum suction cups (not shown), each one slightly more protruding than the next. As the end disk  12  is being pulled through the removed section  38  of stripper plate  36  it is desirable to move slowly until the end disk  12  is completely removed. 
     The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention. 
     PARTS LIST: 
       10  end disk dispensing cassette 
       11  pusher plate bearing 
       12  end disks 
       12   TM  top most end disk 
       12   NA  nearest adjacent end disk 
       14  stack of end disks  12   
       16  light-tight package 
       17  light sensitive web 
       18  removed concentric section of end disk  12   
       20  loading side of end disks  12   
       22  unloading side of end disks  12   
       24  body of cassette  10   
       26  base plate 
       28  standoff 
       30  hub member 
       32  biased pusher plate 
       34  spring 
       36  stripper plate 
       37  relief pockets 
       38  removed section of stripper plate  36   
       40  continuous edge 
       44  end of standoff 
       48  source of air 
       50  air nozzle