Abstract:
The present invention is directed to a wrap device and to methods of using a wrap device for facilitating manipulation of a stack of slides or other stackable objects in order to remove the stack from a packaging container and place within a hopper or other dispensing container. When using the device and methods of the present invention, no undue force is exerted on any particular slide within the stack, thus minimizing the risks of breakage, while stabilizing the stack such that “fanning” and slippage within the stack is substantially prevented. Further, the invention may be used to facilitate manipulation of a stack of slides without direct contact between the slides and a user&#39;s hands.

Description:
CROSS REFERENCE TO RELATED APPLICATION  
       [0001]     The present application is based on and claims priority from U.S. Provisional Patent Application Ser. No. 60/546,046 filed Feb. 19, 2004. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention relates to a device that facilitates the handling and/or transfer of a stack comprising a number of substantially flat, stackable objects including, but not limited to, microscope slides, plates, trays, and the like.  
       BACKGROUND OF THE INVENTION  
       [0003]     A variety of automated or semi-automated instruments exist that require manual loading of multiple slides or other stackable devices into some sort of dispensing container, hopper, or magazine-like structure designed to hold a stack of devices, for example, a stack of about 50 or more microscope slides. Typically, it is difficult to load more than just a few slides at a time by hand into a standard slide hopper due to the tendency of slides within a stack to slip against each other near the middle of the stack. However, the ability to transfer significant numbers of slides, as in a stack of 50 to 100 or more slides, at one time would decrease the amount of time and labor required for loading. Further, since contact of slides with oils, proteins, enzymes, powder and other contaminants on hands or gloves can produce fingerprints, smudges, and/or preparation artifacts, a method of transfer that minimizes manual contact is beneficial in terms of the performance of the slides.  
         [0004]     When a stack of slides is manipulated or moved, care must be taken to avoid “fanning” the stack and to avoid slippage in the middle of the stack. The application of sufficient pressure on the top and bottom of the stack may avoid such mishaps; however, too much pressure can lead to breakage. Therefore it is advantageous to spread the pressure more uniformly over the stack and/or make use of other stabilizing features besides pressure.  
       SUMMARY OF THE INVENTION  
       [0005]     The present invention is directed to devices and methods for facilitating manipulation of a stack of slides, or other stackable objects (referred to collectively as “slides”), to remove the stack from a packaging container and place within a hopper or other dispensing container. When using the device and methods of the present invention, no undue force is exerted on any particular slide within the stack, thus minimizing the risks of breakage, while stabilizing the stack such that “fanning” and slippage within the stack is substantially prevented. Further, the invention may be used to facilitate manipulation of a stack of slides without direct contact between the slides and a user&#39;s hands. 
     
    
     BRIEF DESCRIPTION OF DRAWINGS  
       [0006]      FIG. 1  is a perspective view of one embodiment of the device of the invention as oriented on a packaging container prior to packaging slides.  
         [0007]      FIG. 2  is a perspective view of the embodiment shown in  FIG. 1  with slides filling the packaging container.  
         [0008]      FIG. 3  is a perspective view of one embodiment illustrating a wrap device comprising a strip wrapped around a stack of slides in a packaging container.  
         [0009]      FIG. 4  shows a further view of the embodiment of  FIG. 3  with the excess portion of the strip folded to fit the packaging container.  
         [0010]      FIG. 5  illustrates a method of removing a stack of slides from a packaging container using the device of the present invention.  
         [0011]      FIG. 6  shows the placement of an entire stack of slides at once into an exemplary hopper.  
         [0012]      FIG. 7  illustrates a method of releasing the attachment formed between the attachment means and the attachment site on the wrap device.  
         [0013]      FIG. 8  shows a method of removing the wrap device from a stack of slides via a pulling force applied to one end of the device.  
         [0014]      FIG. 9  shows a stack of slides freed from the wrap device and contained within an exemplary hopper. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0015]     Referring to  FIG. 1 , the invention is a wrap device  2  comprising a strip of flexible, smooth material with adequate strength and toughness to resist unintentional breaking, tearing and cutting when used as described herein. Suitable materials include Tyvek® made from high density polyethylene fibers or Kevlar® made from poly-paraphenylene terephthalamide fibers (both trademarks of E.I. duPont de Nemours Company), as well as nylon, plastic polymers, paper and the like. The material is preferably non-woven, but certain woven materials may be appropriate if the woven fibers are sufficiently fine so as not to abrade the edges of the slides or other stacked objects. It is likewise advantageous that the material used to make the wrap device  2  be dust-free and/or lint-free so as not to leave debris on the stacked objects.  
         [0016]     The wrap device  2  is formed by any number of methods including cutting strips from sheets, or drawing, or molding. The width of the wrap device  2  is sufficient to stabilize movement and prevent “fanning” of slides. For a standard microscope slide (approximately 3 inches in length), a strip of about 1.0 to 2.5 inches in width is suitable, with 1.5-2.0 inches preferred.  
         [0017]     Referring to an embodiment shown in  FIG. 1 , an attachment means is provided at an attachment site  4  for securing an attachment end  5  of the wrap device  2  when the device is later wrapped around a stack of slides. An exemplary attachment means is an adhesive, for example, double-sided tape. A preferred method of making a wrap device  2  is to cut an appropriate length of the device material and then apply approximately 1-2 inches of double-sided adhesive tape (such as any of the double-sided types provided by 3M Corporation) at the attachment site  4 . Alternatively, one may apply a suitable adhesive by brushing, rolling, spraying or the like, to an area on the wrap device  2  to serve as an attachment site  4 . The selected adhesive must be capable of securing the attachment end  5  in a releasable manner. The wrap device  2  is placed in a packaging container  6  with the adhesive side up, as shown in  FIG. 1 , for receiving slides. In an alternative embodiment, adhesive is placed at an attachment end  5  of the wrap device  2 ; for this alternative embodiment, it is preferable to place the wrap device  2  in the container  6  with the adhesive side down. One advantage of applying adhesive to an attachment end  5  of a wrap device  2  is that a single length of strip is adjustable according to the size of the stack and, thus, is usable with stacks containing variable numbers of slides  8 .  
         [0018]     Referring  FIGS. 2 and 3 , in a preferred embodiment, the length of the wrap device  2  is sufficient to wrap around the stack of slides  8  with additional length provided to form an excess end  10 . In use, the attachment end  5  of the wrap device  2  is attached at an attachment site  4  on the wrap device  2 , with the additional length at the excess end  10  serving as a tab for grasping the wrapped stack of slides  8 . Further, the excess end  10  of the wrap device  2  can be used for containing printed instructions, product logos/trademarks, and/or other disclosure. A wrap device  2  with a length ranging from 10 to 15 inches is preferred for handling stack of about 50 to 100 standard microscope slides, but lengths outside this range may be more suitable for other purposes. An approximate suitable length for a wrap device  2  is determined as the summation of: 2a+2b+c, where “a” is the maximum height of the stack, “b” is the width of the stack, and “c” is an allowance for the excess end  10 .  
         [0019]     As an alternative to adhesive, mechanical methods of attaching the attachment end  5  of the wrap device  2  to an attachment site  4  can be used. For example, mechanisms such as snaps, clips, hooks, molded catches and/or a “hook-and-loop” material such as Velcro® (trademark of Velcro Industries B.V.) are suitable for achieving a releasable attachment. The use of certain mechanisms may require that attachment means be placed at the attachment end  5  and at the attachment site  4  of the wrap device  2 , thereby limiting the use of the wrap device  2  to a particular stack size. Mechanical means are affixed to the wrap device  2  through any number of methods known in the art including, but not limited to, gluing, welding and sewing.  
         [0020]     Another alternative means of attachment is “tacking”, such as heat tacking, to create a weak seal between an attachment end  5  of the wrap device  2  and an attachment site  4  on the wrap device  2  at the site of overlap. If tacking is used, the bond formed must be “releasable” without undue demand for strength on the part of the user.  
         [0021]     In a preferred embodiment, the invention contemplates placement of the wrap device  2  around a stack of slides  8  during packaging. For example, referring again to  FIG. 1 , a wrap device  2  is placed over an open packaging container  6  of the type typically used to package a stack of slides  8  for shipping and/or storage, such that both ends of the wrap device  2  are significantly outside the container  6 . Also, the length of the wrap device  2  is placed across the container  6  so as to be perpendicular to the long axis of the microscope slides  8 . Referring to  FIG. 2 , the slides  8 , when placed in the container  6 , rest upon a portion of the flexible wrap device  2  along the bottom of the container  6 , while the ends  5 ,  10  of the wrap device  2  remain outside of the container  6 . Alternatively, the wrap device  2  may be placed around a stack of slides  8  prior to placement of the stack within a container  6 .  
         [0022]     In a preferred embodiment, as shown in  FIG. 3 , the wrap device  2  is wrapped snugly around the stack of slides  8  so that an attachment end  5  is attached to an attachment site  4  on the opposite side of the wrap device  2  to form a releasable adhesion site  12  thereby securing the slides  8  in a tight stack. Preferably, the excess end  10  of the wrap device  2  is folded to fit within the container  6  as shown in  FIG. 4 .  
         [0023]     Referring to  FIG. 5 , the stack of slides  8  is removed from the packaging container  6  without need for contact between the slides  8  and a user&#39;s hands by grasping the wrap device  2  by its excess end  10  or elsewhere on the wrap device  2  and tilting the container  6  to facilitate removal of the stack of slides  8 . Further, the stack of slides  8  is placed within a dispensing magazine or hopper  14  without need for contact between the slides  8  and the user&#39;s hands, by placing fingers or other means of mechanically grasping the stack so that they contact the wrap device  2  as shown in  FIG. 6 .  
         [0024]     Referring to  FIG. 7 , when the stack of slides  8  is contained within the hopper  14 , the wrap device  2  is removed by releasing the adhesive contact through a gentle tugging force exerted on the excess end  10  of the wrap device  2 , countered by downward pressure exerted on the stack of slides  8  by a user&#39;s finger or any other suitable device. As shown in  FIG. 8 , a pulling force applied to the excess end  10  of the wrap device  2  in a relatively smooth motion is used to free the wrap device  2  while the stack of slides  8  remains within the hopper  14  as shown in  FIG. 9 .  
         [0025]     The invention is not limited to use with microscope slides and can be used with other stacked articles including, but not limited to, plates, dishes, lids, and the like. Although the invention has been described with reference to particular embodiments, those skilled in the art can appreciate that variations and modifications can be substituted without substantially departing from the spirit of the invention.