Abstract:
A cassette is received within a sleeve having an open end. Specially folded flaps at the open end are applied to center the cassette in the sleeve and to reduce a width of the open end of the sleeve.

Description:
FIELD OF THE INVENTION 
     The present invention relates to a system for storing and delivering cassettes to a device. 
     BACKGROUND OF THE INVENTION 
     U.S. Pat. No. 4,643,876, incorporated herein by reference, discloses a sterilization system in which an agent such as hydrogen peroxide is introduced into a evacuated sterilizing chamber where it is vaporized and allowed to disperse onto the items to be sterilized. After a desired period of time, electrical energy is applied to the chamber to ionize the gas and form a plasma field at a power level sufficient to achieve sterilization. 
     This system has been successfully commercialized as the STERRAD® Sterilization System and is available from Advance Sterilization Products, Division of Ethicon Endo-Surgery, Inc., Irvine, Calif. The system is used in hospitals and other environments where it is operated repeatedly throughout the day by personnel having a widely varying range of understanding of the apparatus. To ensure simple and automatic operation with adequate safeguards with respect to human error, the system employs an automated delivery system for delivering the liquid sterilant to the sterilization chamber. Measured portions of the sterilant, in this case hydrogen peroxide but many other sterilizing agents could be substituted therefor, are provided in rupturable cells within a rigid cassette housing. A transport system maneuvers the cassette within the STERRAD® sterilizer and releases the given quantity of hydrogen peroxide into the sterilization chamber automatically. One form of cassette and operation of the deliver system are more fully described in the Williams et al. U.S. Pat. No. 4,817,800 issued Apr. 4, 1989; U.S. Pat. No. 4,913,196 issued Apr. 3, 1990; U.S. Pat. No. 4,938,262 issued Jul. 3, 1990; and U.S. Pat. No. 4,941,518 issued Jul. 17, 1990, all of which are incorporated herein by reference. 
     An improved cassette and delivery system is shown in the Williams et al. U.S. Pat. No. 5,882,611 directed to a sleeve which retains and protects the cassette and U.S. Pat. No. 5,877,716 directed to an indicia system on a cassette sleeve. Each of these patents are incorporated herein by reference. The &#39;611 patent describes a sleeve having an inner layer of corrugated cardboard and an outer layer of pressboard, producing a sleeve of considerable thickness. 
     The present cassette and sleeve employ a single layer sleeve which eases manufacturing and reduces the expense of the sleeve and employs a pair of folded tabs to accommodate both the present type of cassette and sleeve and that shown in the &#39;611 patent in the same machine by providing that the important external dimensions of the cassette and sleeve can be the same for each system even though the present system employs a sleeve having a different thickness. 
     SUMMARY OF THE INVENTION 
     A cassette assembly for delivering a substance according to the present invention comprises a cassette having at least one cell therein containing a quantity of the substance and a protective sleeve containing the cassette. The cassettes has a first side, a second side opposite the first side and a first end and the sleeve has a first side, a second side opposite the first side and a first end. A first tab at the sleeve first end extends inwardly from the first side toward the second side and abuts the cassette&#39;s first side. A second tab at the sleeve first end extends inwardly from the second side toward the first side and abuts the cassette&#39;s second side. The cassette has a first lateral dimension between its first side and its second side which is smaller than a second lateral dimension between the sleeve first side and the sleeve second side. 
     Preferably, the cassette further comprises a first face between its first side and its second side and the sleeve further comprises a first edge at its first end between its first side and its second side with the sleeve having a retaining member connected to the sleeve by a hinge at the sleeve first edge and abutting the cassette first face, and with the first tab and the second tab extending inwardly from respective first and second lateral edges of the retaining member. 
     Preferably, the first and second tabs have at least one flap folded inwardly toward the sleeve sides. Preferably, the sleeve is formed of absorbent stock, as for instance cardboard or a coated cardboard, so that a small quantity of the substance on the cassette can be absorbed into the stock. 
     An indicator strip can be provided on the sleeve for indicating the presence of substance thereon. Identifying indicia on the cassette can be provided along with and an aperture through the sleeve in registry with the indicia whereby the indicia can be read through the aperture. 
     A method, according to the present invention, supplies a cassette encased in a sleeve for a machine, the machine having an opening sized to accommodate cassettes having a first fixed dimension between first and second sides thereof and to accommodate sleeves containing the cassettes having a second fixed dimension between first and second sides thereof, the difference between the second and the first dimensions being substantially greater than twice the thickness of the sleeve. The cassette is provided with the first dimension between the first and second sides thereof and the sleeve is provided with the second dimension between the first and second sides thereof. A first tab is folded inwardly from the sleeve first side and a second tab inwardly from the sleeve second side to create a space equaling the first fixed dimension between the first tab and the second tab and the cassette is contained within the sleeve between the first tab and the second tab. Preferably, the cassette is centered in the sleeve between the first and second sides of the sleeve. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a cassette and sleeve according to the present invention, in preparation for entering a sterilization apparatus; 
         FIG. 2  is a cutaway view of a receiver on the sterilization apparatus of  FIG. 1  for receiving the cassette and sleeve of  FIG. 1 ; 
         FIG. 3  is a sectional view taken along lines  3 — 3  of  FIG. 1 , but showing only the cassette without the sleeve; 
         FIG. 4  is a plan view of an unfolded blank for forming the sleeve of  FIG. 1 ; 
         FIG. 5  is an exploded perspective view of the cassette and sleeve; 
         FIG. 6  is a perspective view of the sleeve of  FIG. 1 ; 
         FIG. 7  is a sectional view taken along lines  7 — 7  of  FIG. 1  and showing a retaining tab on the sleeve; 
         FIG. 8  is a detail view a portion of  FIG. 1  showing the folding of tabs on the sleeve; 
         FIG. 9  is a side elevational view of the cassette and sleeve of  FIG. 1 ; and 
         FIG. 10  is a plan view of an unfolded blank for forming an alternative embodiment of a sleeve according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  illustrate a sterilization or other machine  10  and receiver  12  for receiving a cassette  14 . The cassette  14  is received within a protective sleeve  16  which will later be described in more detail. Such a machine and receiver generally comprises a pair of motorized wheels  18  for driving the cassette  14  out of the sleeve  16 , a position sensing switch  20  for detecting the presence of the cassette  14  within the receiver  12 , a bar code reader  22  or other device for reading indicia (to be described later) on the cassette  14  and a controller  24  for controlling the receiver  12 . The cassette  14  has a plurality of cells  26  containing a liquid  28  to be dispensed into the machine  10  (see also  FIG. 3 ) through a hollow piercing needle  30 . In the preferred embodiment, the machine  10  is a sterilizer having a sterilization chamber  32  capable of being lowered to subatmospheric pressures, preferable about 10 Torr or less, and the liquid  28  is hydrogen peroxide which vaporizes in the chamber  32  to create a sterilizing vapor. Such systems are described in more detail in the aforementioned patents. 
     Certain such machines  10  are already commercially available and employ cassettes  14  encased in a thick two layer sleeve such as shown in U.S. Pat. No. 5,882,611. The present cassette  14  is essentially the same as described in the &#39;611 patent. However, the sleeve  16  of the present invention is of a single layer. As shown in  FIG. 4 , the sleeve  16  is folded from a blank  34  of material such as pressboard or other suitable material and folded into a configuration shown in  FIGS. 5 and 6 . Preferably, it is absorbent so that after the spent cassette  14  is returned to the sleeve  16  any droplets of the liquid  28  are absorbed by the sleeve  16 . However, any number of cellulosic or polymeric materials, coated or uncoated, among others, are suitable for the stock. 
     The receiver  12  is adapted to receive the cassette  14  having a first fixed lateral dimension  36  and the sleeve having a second wider fixed lateral dimension  38 . In the prior cassette/sleeve combinations having a two layer sleeve, the cassette  14  fit closely within the sleeve and the sleeve had a thickness of about 0.086 inch due to its two layer construction employing a layer of corrugated cardboard. Sleeves of a smaller dimension due to a thinner construction would not operate suitably in the receiver  12 . Accordingly, the sleeve  16  of the present invention has a unique folded opening  40  with first and second inwardly extending tabs  42  and  44  whereby to provide a sleeve  16  having the same second fixed lateral dimension  38  as the prior sleeves with the two wall construction yet which properly receive the cassette  14  having the first fixed lateral dimension  36 . Additionally, the tabs  42  and  44  provide the needed mechanism to center the cassette  14  in the sleeve  16 . 
     Turning primarily to  FIGS. 4 to 6 , longitudinal fold lines  46  form a top panel  48 , bottom panel  50 , a first side panel  54  and a second side panel  52 . The longitudinal fold lines  46  also form a flap  56  which seals to the second side panel  52  to form the three dimensional structure of the sleeve  16 . Side tabs  58  and a foldable flap  60  form a closed end  62  of the sleeve  16 . An arrow shaped aperture  64  in the sleeve  16  points toward the sleeve open or first end  40 . 
     A lateral fold line  66  at a forward end  68  (at the sleeve open end  40 ) of the bottom panel  50  forms a hinge  70  about which rotates a retaining flap  72 . The retaining flap  72  extends from the fold line  66  to terminate in a tang  74 , a terminal edge  76  of which engages the cassette  14  to retain the cassette  14  within the sleeve  16 . (See also  FIG. 7 ). An annular post  78  surrounds each of a plurality of piercing apertures  80  in the cassette  14  such that each aperture  80  extends axially through the post  78 . The post has a vertical annular sidewall  82  against which the terminal edge  76  abuts. The retaining flap  72  holds the cassette  14  within the sleeve  16 . Additionally, the tabs  42  and  44  can further reinforce the retaining flap  72  to secure the cassette  14  in the sleeve  16  during shipping or after use. Even fairly vigorous shaking will not dislodge the cassette  14  from the sleeve  16 . They are assisted by a pair of central tabs  84  centrally located on the bottom panel  50  which fold inwardly and rearwardly about fold lines  86  to abut an edge (not shown) on the cassette  14  to further hold the cassette  14  within the sleeve  16 . Additional functions of central tabs  84  are fully disclosed in the incorporated U.S. Pat. No. 5,882,611. 
     The first tab  42  extends laterally from a first side  90  of the retaining flap  72  and the second tab  44  extends laterally from a second side  94  of the retaining flap. Each of the first and second tabs  42  and  44  comprise a proximal portion  96  attached to the retaining flap and a distal portion  98  extending forwardly from the proximal portion  96  and separated therefrom by a fold line  100 . The proximal portions  96  are folded inwardly toward each other and the distal portions  98  are folded outwardly over the proximal portions  96  as best seen in  FIG. 8 . This creates the second lateral dimension between the first tab  42  and second tab  44  which accommodates the cassette  14  which has a width slightly smaller than the second lateral dimension. 
     The sleeve  16  contains several additional features, such as openings  102  through the bottom and side panels through which driving wheels (not shown) in the receiver  12  can access the cassette  14 . A pair of chemical indicator strips  104  shows whether the sleeve  16  has been exposed to hydrogen peroxide (or, as adapted, to whatever is stored therein). The cassette  14  and sleeve  16  are preferably supplied within a non-permeable overwrap (not shown), such as a sealed clear plastic wrap. If the indicator strips  104  show a color change then the operator knows that the hydrogen peroxide contained in the cassette  14  has leaked and should not open the overwrap. Instructions to this effect are also provided on the sleeve  16 . A bar code  106  can provide machine readable information on what is contained in the cassette  14 , lot numbers, expiration dates, serial numbers and the like. Each cassette  14  can have a unique identification number or code encoded into the bar code  106 . A used cassette  14  can be easily recognized by storing and comparing the unique identification number or code in the memory of the controller  24  each time a cassette  14  is placed in the receiver  12 . Used cassettes  14  can thus be rejected. Turning also to  FIG. 9 , a window  108  through the sleeve  16  can show printed indicia  110  on the cassette  14  indicative of lot numbers and expiration dates and the like. 
       FIG. 10  illustrates an alternative embodiment of a sleeve  200  according to the present invention. It is similar in most respects to the sleeve  16 . However, it employs tabs  202  similar to tabs  42  and  44  but which do not fold upon themselves. They are but a single layer. Of course, the tabs could alternatively be structured to fold more than once so as to produce a tab of three, four or more layers depending upon the thickness of the material and the desired dimensions. 
     While the invention has been described with regard to a particular embodiment thereof, those skilled in the art will understand, of course, that the invention is not limited thereto since modifications can be made by those skilled in the art, particularly in light of the foregoing teachings. Reasonable variation and modification are possible within the foregoing disclosure of the invention without departing from the spirit of the invention.